Theoretical densities of the most recurring polymers found in the environment.
\r\n\t
",isbn:"978-1-83969-591-9",printIsbn:"978-1-83969-590-2",pdfIsbn:"978-1-83969-592-6",doi:null,price:0,priceEur:0,priceUsd:0,slug:null,numberOfPages:0,isOpenForSubmission:!0,hash:"e39a567d9b6d2a45d0a1d927362c9005",bookSignature:"Dr. Umar Zakir Abdul Hamid and Associate Prof. Ahmad 'Athif Mohd Faudzi",publishedDate:null,coverURL:"https://cdn.intechopen.com/books/images_new/10778.jpg",keywords:"Model-Based Control, Optimal Control, Industrial Automation, Linear Actuator, Nonlinear Actuator, System Identification, Soft Robotics, Service Robots, Unmanned Aerial Vehicle, Autonomous Vehicle, Process Engineering, Chemical Engineering",numberOfDownloads:null,numberOfWosCitations:0,numberOfCrossrefCitations:null,numberOfDimensionsCitations:null,numberOfTotalCitations:null,isAvailableForWebshopOrdering:!0,dateEndFirstStepPublish:"February 25th 2021",dateEndSecondStepPublish:"March 25th 2021",dateEndThirdStepPublish:"May 24th 2021",dateEndFourthStepPublish:"August 12th 2021",dateEndFifthStepPublish:"October 11th 2021",remainingDaysToSecondStep:"21 days",secondStepPassed:!1,currentStepOfPublishingProcess:2,editedByType:null,kuFlag:!1,biosketch:"Umar Zakir Abdul Hamid, Ph.D. is an autonomous vehicle expert, and with more than 30 scientific publications under his belt, Umar actively participates in global automotive standardization efforts and is a Secretary for a Society of Automotive Engineers (SAE) Committee.",coeditorOneBiosketch:"Associate Professor Dr. Ahmad 'Athif Mohd Faudzi has more than 100 scientific publications as of 2021 and is currently leading a team of 18 researchers in UTM doing research works on control, automation, and actuators.",coeditorTwoBiosketch:null,coeditorThreeBiosketch:null,coeditorFourBiosketch:null,coeditorFiveBiosketch:null,editors:[{id:"268173",title:"Dr.",name:"Umar Zakir Abdul",middleName:null,surname:"Hamid",slug:"umar-zakir-abdul-hamid",fullName:"Umar Zakir Abdul Hamid",profilePictureURL:"https://mts.intechopen.com/storage/users/268173/images/system/268173.jpg",biography:"Umar Zakir Abdul Hamid, PhD has been working in the autonomous vehicle field since 2014 with various teams in different countries (Malaysia, Singapore, Japan, Finland). He is now leading a team of 12 engineers working in the Autonomous Vehicle Software Product Development with Sensible 4, Finland. Umar is one of the recipients for the Finnish Engineering Award 2020 for his contributions to the development of all-weather autonomous driving solutions with the said firm. He is an aspiring automotive thought leader and often invited as a guest and keynote speaker to industrial and technical events. With more than 30 scientific and technical publications as author and editor under his belt, Umar actively participates in global automotive standardization efforts where he is a Secretary for a Society Automotive Engineers (SAE) Committee.",institutionString:"Sensible 4 Oy",position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"0",totalChapterViews:"0",totalEditedBooks:"1",institution:null}],coeditorOne:{id:"204176",title:"Associate Prof.",name:"Ahmad 'Athif Mohd",middleName:null,surname:"Faudzi",slug:"ahmad-'athif-mohd-faudzi",fullName:"Ahmad 'Athif Mohd Faudzi",profilePictureURL:"https://mts.intechopen.com/storage/users/204176/images/system/204176.png",biography:"Assoc. Prof. Ir. Dr. Ahmad `Athif Bin Mohd Faudzi received the B. Eng. in Computer Engineering, the M. Eng. in Mechatronics and Automatic Control from Universiti Teknologi Malaysia, Malaysia and the Dr. Eng. in System Integration from Okayama University, Japan in 2004, 2006, and 2010 respectively. He was a Visiting Research Fellow at the Tokyo Institute of Technology from 2015 to 2017. From March 2019 to date, he is the Director of the Centre for Artificial Intelligence and Robotics (CAIRO), Universiti Teknologi Malaysia, Malaysia. He is mainly engaged in the research fields of actuators (pneumatic, soft mechanism, hydraulic, and motorized actuators) concentrate his work in field robotics, bioinspired robotics and biomedical applications. He is a Professional Engineer (PEng), a Charted Engineer (CEng), a member of the IEEE Robotics and Automation Society (RAS) and a member of two Akademi Sains Malaysia Special Interest Group (ASM SIG) of Biodiversity and Robotics. He is also the recipient of Top Research Scientist Malaysia (TRSM) 2020 in the area of Robotics. As of 2021, he has more than 100 scientific publications and leads a team of 18 researchers in UTM doing research works on automation and actuators.",institutionString:"University of Technology Malaysia",position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"0",totalChapterViews:"0",totalEditedBooks:"0",institution:{name:"University of Technology Malaysia",institutionURL:null,country:{name:"Malaysia"}}},coeditorTwo:null,coeditorThree:null,coeditorFour:null,coeditorFive:null,topics:[{id:"11",title:"Engineering",slug:"engineering"}],chapters:null,productType:{id:"1",title:"Edited Volume",chapterContentType:"chapter",authoredCaption:"Edited by"},personalPublishingAssistant:{id:"346794",firstName:"Mia",lastName:"Miskulin",middleName:null,title:"Ms.",imageUrl:"https://mts.intechopen.com/storage/users/346794/images/15795_n.png",email:"mia@intechopen.com",biography:"As an Author Service Manager my responsibilities include monitoring and facilitating all publishing activities for authors and editors. From chapter submission and review, to approval and revision, copyediting and design, until final publication, I work closely with authors and editors to ensure a simple and easy publishing process. I maintain constant and effective communication with authors, editors and reviewers, which allows for a level of personal support that enables contributors to fully commit and concentrate on the chapters they are writing, editing, or reviewing. I assist authors in the preparation of their full chapter submissions and track important deadlines and ensure they are met. I help to coordinate internal processes such as linguistic review, and monitor the technical aspects of the process. As an ASM I am also involved in the acquisition of editors. Whether that be identifying an exceptional author and proposing an editorship collaboration, or contacting researchers who would like the opportunity to work with IntechOpen, I establish and help manage author and editor acquisition and contact."}},relatedBooks:[{type:"book",id:"1591",title:"Infrared Spectroscopy",subtitle:"Materials Science, Engineering and Technology",isOpenForSubmission:!1,hash:"99b4b7b71a8caeb693ed762b40b017f4",slug:"infrared-spectroscopy-materials-science-engineering-and-technology",bookSignature:"Theophile Theophanides",coverURL:"https://cdn.intechopen.com/books/images_new/1591.jpg",editedByType:"Edited by",editors:[{id:"37194",title:"Dr.",name:"Theophanides",surname:"Theophile",slug:"theophanides-theophile",fullName:"Theophanides Theophile"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"3092",title:"Anopheles mosquitoes",subtitle:"New insights into malaria vectors",isOpenForSubmission:!1,hash:"c9e622485316d5e296288bf24d2b0d64",slug:"anopheles-mosquitoes-new-insights-into-malaria-vectors",bookSignature:"Sylvie Manguin",coverURL:"https://cdn.intechopen.com/books/images_new/3092.jpg",editedByType:"Edited by",editors:[{id:"50017",title:"Prof.",name:"Sylvie",surname:"Manguin",slug:"sylvie-manguin",fullName:"Sylvie Manguin"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"3161",title:"Frontiers in Guided Wave Optics and Optoelectronics",subtitle:null,isOpenForSubmission:!1,hash:"deb44e9c99f82bbce1083abea743146c",slug:"frontiers-in-guided-wave-optics-and-optoelectronics",bookSignature:"Bishnu Pal",coverURL:"https://cdn.intechopen.com/books/images_new/3161.jpg",editedByType:"Edited by",editors:[{id:"4782",title:"Prof.",name:"Bishnu",surname:"Pal",slug:"bishnu-pal",fullName:"Bishnu Pal"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"72",title:"Ionic Liquids",subtitle:"Theory, Properties, New Approaches",isOpenForSubmission:!1,hash:"d94ffa3cfa10505e3b1d676d46fcd3f5",slug:"ionic-liquids-theory-properties-new-approaches",bookSignature:"Alexander Kokorin",coverURL:"https://cdn.intechopen.com/books/images_new/72.jpg",editedByType:"Edited by",editors:[{id:"19816",title:"Prof.",name:"Alexander",surname:"Kokorin",slug:"alexander-kokorin",fullName:"Alexander Kokorin"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"1373",title:"Ionic Liquids",subtitle:"Applications and Perspectives",isOpenForSubmission:!1,hash:"5e9ae5ae9167cde4b344e499a792c41c",slug:"ionic-liquids-applications-and-perspectives",bookSignature:"Alexander Kokorin",coverURL:"https://cdn.intechopen.com/books/images_new/1373.jpg",editedByType:"Edited by",editors:[{id:"19816",title:"Prof.",name:"Alexander",surname:"Kokorin",slug:"alexander-kokorin",fullName:"Alexander Kokorin"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"57",title:"Physics and Applications of Graphene",subtitle:"Experiments",isOpenForSubmission:!1,hash:"0e6622a71cf4f02f45bfdd5691e1189a",slug:"physics-and-applications-of-graphene-experiments",bookSignature:"Sergey Mikhailov",coverURL:"https://cdn.intechopen.com/books/images_new/57.jpg",editedByType:"Edited by",editors:[{id:"16042",title:"Dr.",name:"Sergey",surname:"Mikhailov",slug:"sergey-mikhailov",fullName:"Sergey Mikhailov"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"371",title:"Abiotic Stress in Plants",subtitle:"Mechanisms and Adaptations",isOpenForSubmission:!1,hash:"588466f487e307619849d72389178a74",slug:"abiotic-stress-in-plants-mechanisms-and-adaptations",bookSignature:"Arun Shanker and B. Venkateswarlu",coverURL:"https://cdn.intechopen.com/books/images_new/371.jpg",editedByType:"Edited by",editors:[{id:"58592",title:"Dr.",name:"Arun",surname:"Shanker",slug:"arun-shanker",fullName:"Arun Shanker"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"878",title:"Phytochemicals",subtitle:"A Global Perspective of Their Role in Nutrition and Health",isOpenForSubmission:!1,hash:"ec77671f63975ef2d16192897deb6835",slug:"phytochemicals-a-global-perspective-of-their-role-in-nutrition-and-health",bookSignature:"Venketeshwer Rao",coverURL:"https://cdn.intechopen.com/books/images_new/878.jpg",editedByType:"Edited by",editors:[{id:"82663",title:"Dr.",name:"Venketeshwer",surname:"Rao",slug:"venketeshwer-rao",fullName:"Venketeshwer Rao"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"4816",title:"Face Recognition",subtitle:null,isOpenForSubmission:!1,hash:"146063b5359146b7718ea86bad47c8eb",slug:"face_recognition",bookSignature:"Kresimir Delac and Mislav Grgic",coverURL:"https://cdn.intechopen.com/books/images_new/4816.jpg",editedByType:"Edited by",editors:[{id:"528",title:"Dr.",name:"Kresimir",surname:"Delac",slug:"kresimir-delac",fullName:"Kresimir Delac"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"3621",title:"Silver Nanoparticles",subtitle:null,isOpenForSubmission:!1,hash:null,slug:"silver-nanoparticles",bookSignature:"David Pozo Perez",coverURL:"https://cdn.intechopen.com/books/images_new/3621.jpg",editedByType:"Edited by",editors:[{id:"6667",title:"Dr.",name:"David",surname:"Pozo",slug:"david-pozo",fullName:"David Pozo"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}}]},chapter:{item:{type:"chapter",id:"46096",title:"Functional MRI in Alzheimer’s Disease",doi:"10.5772/58264",slug:"functional-mri-in-alzheimer-s-disease",body:'Alzheimer’s disease (AD) is the most common form of dementia affecting millions of people worldwide. AD results in progressive brain atrophy, memory loss and widespread neurologic deterioration. The first AD-related neuropathological changes appear in the medial temporal lobe (MTL) memory structures already years prior to the manifestation of clinical dementia. Atrophy of the MTL structures as revealed by structural magnetic resonance imaging (MRI) is nowadays considered to be a valid diagnostic marker at the mild cognitive impairment stage, although structural imaging findings may be somewhat nonspecific. “Mild cognitive impairment” (MCI) is in fact one of the recent concepts to describe the possible prodromal state of AD, that is a stage between healthy aging and full-blown clinical AD, for example in terms of neuropathological, imaging and cognitive changes.
Despite extensive research, the fundamental neural basis of memory impairment characteristic to early AD is still largely unknown. Particularly, the relationship between β-amyloid (Aβ) pathology and alterations in memory function remains to be fully elucidated. During recent years, clinical functional MRI (fMRI) has provided tools to investigate the neural underpinnings of AD-related cognitive alterations and thus novel insights into the pathognomonic changes in the MTL structures and related whole-brain memory networks. The ultimate clinical goal of fMRI research is to develop means to reliably define alterations in brain function related to the earliest symptoms of AD before development of significant irreversible structural damage. Since the MTL memory structures are known to be the site of early neuropathological alterations (e.g., neurofibrillary tangles) in AD, previous fMRI studies have largely focused on investigating this particular region of the brain. FMRI during tasks probing episodic memory encoding, which is the cognitive function most characteristically impaired in early AD, is of particular interest.
In this chapter, we will summarize previous studies demonstrating changes in task-related fMRI activity, primarily focusing on memory tasks, as well as studies investigating resting state fMRI findings in clinical AD patients compared to healthy elderly individuals. In a nutshell, fMRI studies in AD patients have demonstrated hypoactivation of the MTL structures during memory task performance, whereas studies in elderly individuals with MCI have reported both increased and decreased MTL responses depending on the severity of the cognitive impairment and underlying structural atrophy. Additionally, recent fMRI findings in MCI and AD patients are beginning to reveal functional abnormalities between the MTL and posteromedial regions such as posterior cingulate and precuneal cortices. In addition to MCI and clinical AD, we will also review recent advances in our understanding of the neuroimaging correlates of cognitively intact elderly subjects at increased risk to develop AD in terms of carrying the apolipoprotein E ε4 (APOE ε4) allele.
The long asymptomatic or minimally symptomatic phase of AD provides a potential period for early therapeutic interventions to slow down – and perhaps ultimately prevent – the progression to clinical dementia. Large-scale worldwide multimodal imaging studies on reliable predictors of AD are on-going. There is great hope that imaging of the MTL memory structures and related whole-brain networks would facilitate early diagnosis of AD and other dementias as well as improve treatment options of these devastating diseases in the near future.
AD was originally described in 1907 by the German physician Alois Alzheimer (Alzheimer, 1907; Maurer et al., 1997). Today it is the most common form of dementia in the elderly (Bookmayer et al., 1998). AD is a progressive neurodegenerative syndrome which typically begins with insidious impairment of episodic memory (i.e., memory for past personal experiences in a particular spatial and temporal context).
The most common form of AD is often termed sporadic or late-onset AD as opposed to the relatively rare early-onset forms of the disease (Tanzi & Bertram, 2001). For late-onset AD, the main known genetic risk factor is the APOE ε4 allele in chromosome 19 (Bertram et al., 2007; Saunders et al., 1993). Neuropathologically, the disease is characterized by the accumulation of extracellular deposits of Aβ plaques, intracellular neurofibrillary tangles (NFTs) consisting of hyperphosphorylated tau protein, and brain atrophy with regional synaptic, neuronal, and axonal loss (Braak & Braak, 1991). Interestingly, as opposed to the NFT pathology, at the early stages of the disease, Aβ accumulation is often modest within the MTL memory structures but more pronounced, for example, in the posteromedial cortices of the brain. Presentation and clinical course of the AD syndrome can, however, be very variable. Accordingly, AD can be heterogeneous in terms of genetic background (Bertram et al., 2007), response to treatment (Kaduszkiewicz et al., 2005) as well as neuropathological and neuroradiological patterns (Henry-Feugeas, 2007; Jagust et al., 2008;\n\t\t\t\tJellinger, 2002).
The diagnosis of AD relies on clinical judgement. Perhaps the most widely used criteria for defining AD were developed by the National Institute of Neurological and Communicative Disorders and Stroke / Alzheimer’s Disease and Related Disorders Association (NINCDS-ADRDA; McKhann et al., 1984). A recent proposal for new research criteria for AD suggests that various biomarkers could be used as supportive features in the diagnostics to improve the specific identification of AD as early as possible (Dubois et al., 2007; Dubois et al., 2010). According to this suggestion, the diagnosis of AD requires meeting the core criterion of significant episodic memory impairment together with at least one or more of the supportive biomarker criteria. Hippocampal atrophy as revealed by structural MRI is one of the most widely documented supportive biomarkers of AD, in addition to abnormal cerebrospinal fluid (CSF) Aβ and tau findings, and a specific pattern of temporoparietal hypometabolism as indicated by [18F]fluorodeoxyglucose positron emission tomography (FDG-PET). Currently, a diagnosis of definite AD can, however, only be done by post mortem neuropathological evaluation.
The concept of MCI (mild cognitive impairment) refers to subjects with cognitive impairment beyond that expected for their age and education but who are not demented (Petersen et al., 1999; Petersen et al., 2001; Petersen et al., 2004; Petersen et al., 2009; Winblad et al., 2004). During recent years, MCI has had a number of definitions. Diagnostic criteria for the amnestic subtype of MCI widely used during recent years are as follows: 1) memory complaint, preferably corroborated by an informant; 2) objective memory impairment; 3) normal general cognitive function; 4) intact activities of daily living; and 5) not demented (Petersen et al., 2001). Persons who present with amnestic MCI have an increased risk of developing clinical AD with an annual conversion rate of 12 – 15 %, in contrast to 1 – 2 % risk of conversion in healthy elderly individuals (Petersen et al., 1999). Not all subjects with MCI progress to dementia / AD, but a high number of MCI subjects remain stable or may even revert back to normal during follow-up (Ganguli et al., 2004; Gauthier et al., 2006; Larrieu et al., 2002; Petersen, 2004). As noted above, however, a lively discussion on revisions of the MCI / AD diagnostic criteria is on-going among researchers and clinicians.
During the past fifteen years, fMRI – together with complementary imaging modalities and sophisticated data analysis methods – has proved to be a very useful tool in investigating the neural basis of intact human memory and other higher cognitive functions. Activation of the hippocampal and parahippocampal regions of the MTL during successful memory encoding has been demonstrated in several fMRI studies in healthy young subjects (Brewer et al., 1998; Pihlajamäki et al., 2003; Sperling et al., 2003b; Stern et al., 1996; Wagner et al., 1998;). These human fMRI findings strongly support the notion that the MTL structures are critical for encoding new events into long-term memory (Eichenbaum, 2000; Mesulam, 1998; Squire & Zola-Morgan, 1991).
Clinical fMRI research into the pathophysiology of age-associated neurodegenerative diseases has become established more recently. Neuroimaging tools such as fMRI provide in vivo methods to investigate the integrity of the resting human brain as well as mapping neural networks supporting higher cognitive functions (e.g., memory). fMRI is non-invasive, radiation-free and offers a combination of good spatial and reasonable temporal resolution. Nowadays, the most widely used fMRI technique to measure hemodynamic changes related to underlying cellular activity is based on imaging of the endogenous blood-oxygen-level-dependent (BOLD) contrast (Kwong et al., 1992; Ogawa et al., 1992). In a nutshell, the relative decrease in the amount of deoxygenated hemoglobin enhances the MRI signal locally in brain areas activated during a particular cognitive task. In addition to observed increases in BOLD signal in “activated” brain areas, it has recently been shown that negative BOLD responses are also related to underlying neural activity and originate in decreases in neuronal activity below spontaneous activity in “deactivated” brain regions (Logothetis et al., 2001;\n\t\t\t\tShmuel et al., 2006).
Typically, fMRI experiments compare the BOLD signal during one cognitive condition (e.g., encoding novel pictures) to a control task (e.g., viewing familiar pictures) or to a passive baseline condition (e.g., visual fixation on a cross-hair). This can be done in a “block design” paradigm, in which stimuli of each cognitive condition are grouped together in blocks lasting 20–40 s, or in “event-related” paradigms, in which single stimuli from several different conditions are interspersed.
In addition to functional activation studies, there has recently been considerable interest in studying the baseline activity, or the “default mode” activity, of the resting human brain using FDG-PET and various fMRI techniques (Buckner et al., 2005; Gusnard & Raichle, 2001). It is very interesting that the same brain areas which show high default mode activity and predilection for task-induced fMRI deactivation responses have also demonstrated the earliest hypometabolic changes in AD in previous FDG-PET studies as well as early accumulation of Aβ pathology in recent molecular PET studies using a tracer called [11C]Pittsburgh Combound B, or PIB (Buckner et al., 2005; Cavanna & Trimble, 2006; Klunk et al., 2004; Minoshima et al., 1997; Nestor et al., 2003).
Taken together, fMRI based on BOLD contrast offers a unique, safe and widely available technique for the study of intact human cognition as well as alterations in neuronal function related to healthy aging and dysfunction related to neurodegenerative diseases such as AD.
The hallmark of early AD is the inability to form new enduring episodic memories. At the same time, mild AD patients typically present with neuropathological changes such as synaptic alterations, selective neuronal loss and neurofibrillary tangles in the MTL structures (Braak & Braak 1991; Gomez-Isla et al., 1997; Hyman et al., 1984; Kordower et al., 2001; Scheff et al., 2006; Scheff et al., 2007). In addition to the critical role of the MTL, successful memory formation is thought to require a carefully synchronized interplay between the MTL and large-scale neural networks (Buckner et al., 2005; Eichenbaum, 2000; Lavenex & Amaral, 2000; Mesulam, 1998; Squire & Zola-Morgan, 1991; Suzuki, 2007; Tulving & Markowitsch, 1998).
Given the prominence of MTL pathology and structural atrophy in early AD, the pioneering fMRI studies on AD focused on investigating alterations in hippocampal activation during various episodic memory tasks (Kato et al., 2001; Machulda et al., 2003; Rombouts et al., 2000; Small et al., 1999; Sperling et al., 2003a). To date, there are several fMRI studies, which have consistently reported diminished or absent MTL activation in AD compared to healthy elderly controls (Fig. 1), during encoding numerous different types of novel stimuli such as faces, face-name pairs, line-drawings, scenes, and geometric shapes (Dickerson et al., 2005; Golby et al., 2005; Grön & Riepe, 2004; Hämäläinen et al., 2007; Kato et al., 2001; Machulda et al., 2003; Pariente et al., 2005; Remy et al., 2005; Rombouts et al., 2000; Small et al., 1999; Sperling et al., 2003a).
Subjects with amnestic MCI (Petersen et al., 2001; Petersen et al., 2009) are an important group to investigate, as they are at increased risk for developing dementia, AD in particular. Consonant with the notion of clinical heterogeneity, results of fMRI studies in MCI subjects relative to controls and AD patients have been variable, findings of hippocampal activation ranging from hyperactivation during encoding (Dickerson et al., 2004; Dickerson et al., 2005; Hämäläinen et al., 2007; Kircher et al., 2007; Woodard et al., 2009;\n\t\t\t\t\tYassa et al., 2010) to hypoactivation both during encoding and retrieval tasks (Johnson et al., 2006a; Machulda et al., 2003; Mandzia et al., 2009; Petrella et al., 2006). In addition to the heterogeneity of the MCI population, some of the diversity of fMRI results in MCI subjects may be explained by differences in subject selection criteria and the level of clinical severity and underlying MTL atrophy, fMRI paradigms and their difficulty as well as functional imaging and data analysis methods. The mechanistic underpinnings of the observed MTL hyperactivation still remain unclear. In addition to pathological changes in cellular, synaptic or neurotransmitter activity, for example, multiple non-neural factors (such as resting hypoperfusion and metabolism) may also confound the interpretation of BOLD fMRI results in MCI and AD. Typically MCI subjects with significantly impaired memory have, however, similar to AD patients, shown decreased hippocampal activity compared with controls (Machulda et al., 2003; Petrella et al., 2006).
Increased fMRI activity in neocortical (A) and medial temporal (B) brain areas during processing of repeated face-name stimuli in patients with Alzheimer’s disease (in red) relative to healthy older control subjects (in yellow). A: Crosshair is located in the right (R) prefrontal cortex, MNI coordinate: 40, 8, 50; B: Crosshair is located in the left (L) anterior hippocampus, MNI coordinate: -24, -4, -28.
Interestingly, there is also evidence of increased MTL activity in AD patients during specific contrasts, primarily involving the brain response to repetitive stimuli. Golby et al. (2005) reported impaired fMRI repetition suppression paralleled by more MTL activation in AD patients than in older controls during processing of repeated scenes. Another recent study provided evidence that the normal suppression of MTL activity to repeated face-name pairs as compared to visual fixation is impaired in AD (Pihlajamäki et al., 2008). Similar findings have been reported in individuals with amnestic MCI (Johnson et al., 2004). Failure of the hippocampus and surrounding MTL cortices to discriminate familiar from novel information at encoding has also been related to both poor associative recognition memory and poor performance in neuropsychological tests of episodic memory across a range of age and cognitive impairment (Pihlajamäki et al., 2011).
As mentioned above, not only the hippocampus but also whole-brain neural networks interconnected with the MTL, are critical for higher cognitive functions such as episodic memory formation (Buckner et al., 2005; Eichenbaum, 2000; Mesulam, 1998). It can be hypothesized that – as opposed to focal changes in the MTL only – multiple nodes within these networks and their mutual interconnectivity are affected at the earliest stage of AD (Scheff et al., 2006; Selkoe, 2002). A recent meta-analysis (Schwindt & Black, 2009) of both fMRI and FDG-PET memory activation studies of AD identified several cortical regions as being more likely to show greater encoding-related activation in controls than in AD patients, including the ventrolateral prefrontal, precuneal, cingulate and lingual cortices. On the other hand, in addition to consistent findings of decreased MTL activation during novel encoding memory tasks, several groups have found evidence of increased fMRI or PET activation in neocortical brain regions, such as frontal and parietal cortices in mild AD patients compared to controls (Grady et al., 2003; Sperling et al., 2003a; Pariente et al., 2005; Celone et al., 2006). This may represent a compensatory process in the setting of MTL dysfunction.
In summary, previous fMRI studies in AD patients, compared to healthy elderly individuals, have reported decreased MTL activity during processing of novel versus repeated information (Dickerson et al., 2005; Golby et al., 2005; Rombouts et al., 2000; Sperling et al., 2003b). These findings of decreased hippocampal activity when comparing novel to repeated stimuli in AD or MCI patients are, in fact, likely to be explained at least to some degree by failure of hippocampal repetition suppression to repeatedly presented stimuli as reviewed above (Golby et al., 2005; Johnson et al., 2004; Pihlajamäki et al., 2008; Pihlajamäki et al., 2011). There is also converging evidence that AD patients show increases in brain activity to compensate for cognitive difficulties in brain regions such as frontal areas that are pathologically less affected than the MTL at the early stages of the disease (Braak & Braak, 1991; Johnson & Albert, 2000; Lehtovirta et al., 1996). Future studies combining multiple imaging modalities such as various structural and functional MRI techniques and PIB-PET imaging (Klunk et al., 2004) are likely to expand our knowledge of the relationships between cognitive impairment, neuropathological changes and alterations in functional imaging patterns.
Several experiments in cognitively intact elderly control subjects have demonstrated that elderly individuals are able to activate their hippocampus during successful associative encoding largely to the same degree as young subjects (Miller et al., 2008a; Rand-Giovannetti et al., 2006; Sperling et al., 2003a; Sperling et al., 2003b), although age-related alterations in fMRI activity during normal aging have also been reported (Cabeza et al., 2004; Daselaar et al., 2006a, Daselaar et al., 2006b;\n\t\t\t\t\tDennis et al., 2007). It has been suggested that age-related changes in memory performance may primarily be due to alterations in cortical regions or in the connectivity between the MTL and neocortical regions.
Similarly to MCI subjects, results of fMRI studies comparing activation in APOE ε4 carriers at risk for AD versus their non-carrier counterparts have been diverse. Increased hippocampal and cortical activation has been reported during tasks such as encoding novel and repeated pictures or face-name pairs, encoding and retrieval of word-pairs, a letter fluency task, and an auditory verbal n-back working memory task, and has usually been interpreted to reflect compensatory neural mechanisms (Bondi et al., 2005; Bookheimer et al., 2000;\n\t\t\t\t\tBurggren et al., 2002; Dickerson et al., 2005; Fleisher et al., 2005; Han et al., 2007; Pihlajamäki & Sperling, 2009; Smith et al., 2002; Wishart et al., 2006). At the same time, several studies have demonstrated reduced functional brain activity in the MTL and other brain areas in cognitively normal ε4 carriers (Borghesani et al., 2007; Lind et al., 2006; Smith et al., 1999; Trivedi et al., 2006). Several of the above mentioned studies have carefully matched the study groups regarding age, gender and cognitive performance. It is difficult to draw firm conclusions of the ε4 effects on BOLD fMRI activation pattern. In the most recent large-scale fMRI studies, more complex patterns of alterations in brain activation differentially affected by APOE ε4 and family history of AD have been suggested (Bassett et al., 2006; Johnson et al., 2006). Longitudinal fMRI testing of subjects at genetic risk for AD would likely be informative, optimally in combination with metabolic FDG- and molecular PIB-PET imaging to improve our understanding of the temporal sequence of events early in the course of prodromal AD.
Since some of the MCI subjects will remain stable and some will progress to dementia over time, great interest has been focused on attempts to identify the features predicting future conversion from MCI to clinical AD. As reviewed above, previous cross-sectional fMRI studies in subjects with MCI / prodromal AD have reported variable results, ranging from MTL hypoactivation to hyperactivation compared to cognitively normal elderly individuals. It has been hypothesized that subjects in early phases of prodromal AD may present a short period of paradoxical hippocampal hyperactivation, which is then followed by loss of hippocampal activation along with progressive cognitive decline. FMRI studies with clinical follow-up data on MCI subjects have reported that increased MTL activity at baseline in MCI compared to elderly control subjects may indicate higher likelihood of subsequent cognitive decline (Dickerson et al., 2004; Miller et al., 2008b). Similar findings of a temporary period with abnormally enhanced MTL activity during a preclinical stage of AD have been reported in APOE ε4 carriers relative to non-carriers (Bookheimer et al., 2000).
Recently, one longitudinal fMRI study (O’Brien et al., 2010) demonstrated both the highest hippocampal activation at baseline and the greatest loss of hippocampal activation during follow-up in cognitively impaired subjects with the most rapid decline during the follow-up period. The authors concluded that cognitive decline is associated with loss of hippocampal activation and suggested that fMRI may prove valuable in tracking very early progression of brain dysfunction on the trajectory towards clinical AD but prior to the point of irreversible neuronal loss and significant macroscopic atrophy. Thus, it seems that there may be a temporary phase of abnormal MTL hyperactivity along the course of MCI to clinical AD, which may in turn be an indicator of compensatory neural mechanisms recruited in MCI subjects in order to keep memory performance close to the level of cognitively normal elderly subjects. Around the conversion from MCI to clinical AD, the ability to compensate for the MTL pathology is lost, which is then seen as poor task performance and disrupted hippocampal fMRI activity. In other words, hippocampal hyperactivity observed in some previous fMRI studies during the progression of MCI to clinical AD may be a compensatory phenomenon, but it may also be a harbinger of impending hippocampal failure.
In addition to task-related fMRI activation studies primarily focusing on the MTL function, recent functional imaging studies have demonstrated AD-related alterations in the so called brain “default mode”, or resting state activity. The default mode of the human brain was originally identified by its consistent activity increases during passive task states as compared to a wide range of goal-directed activation tasks (Buckner et al., 2008; Gusnard & Raichle, 2001; Mazoyer et al., 2001; Raichle et al., 2001; Shulman et al., 1997). Regions of the default network show high resting glucose metabolism and blood flow relative to other brain regions as well as coordinated low frequency fluctuations in states of relative rest (Buckner et al., 2008; Minoshima et al., 1997; Raichle et al., 2001; Shulman et al., 1997). Anatomically, the key default mode regions consist of the posteromedial and lateral parietal regions as well as midline and lateral frontal regions. Interestingly, the same default mode regions which are upregulated at rest appear to be suppressed during various cognitive activities, including intentional encoding of new memories (Pihlajamäki et al., 2008; Rombouts et al., 2005a; Shulman et al., 1997). Deactivation of key nodes of the default mode network, in coordination with hippocampal activation, seems in fact to be a prerequisite for successful memory encoding (Daselaar et al., 2004; Miller et al., 2008a; Weissman et al., 2006).
FMRI deactivation areas during processing of repeated face-name stimuli in healthy older subjects (in blue). Crosshair is located in the left (L) posterior cingulated cortex, MNI coordinate: -6, -40. 38.
Previous FDG-PET studies in clinical AD patients and older individuals at risk for AD have revealed hypometabolism of the posteromedial and other association cortical regions (Herholz et al. 2002; Minoshima et al. 1997; Mosconi et al. 2008b; Rapoport 1991; Reiman et al., 1996). In recent fMRI studies of AD, corresponding brain default mode regions have been found to demonstrate an abnormal fMRI task-induced deactivation pattern (Greicius et al., 2004; Lustig et al., 2003; Petrella et al., 2007a; Petrella et al., 2007b; Pihlajamäki et al., 2008; Rombouts et al., 2005a; Rombouts et al., 2005b). Predilection of the posteromedial core regions of the default network to demonstrate task-induced deactivation (i.e., relative decreases in the BOLD fMRI signal) during paradigms requiring attention to external stimuli has been consistently demonstrated in both young and old healthy subjects (Fig. 2) using a multitude of cognitive stimuli and both fMRI and PET imaging modalities (Buckner et al., 2005, 2008; Cavanna & Trimble, 2006; Daselaar et al., 2004; Fransson & Marrelec, 2008; Gusnard et al., 2001; Mazoyer et al., 2001; Miller et al., 2008a; Otten & Rugg, 2001; Raichle et al., 2001; Shulman et al., 1997). In other words, the relative decreases in fMRI signal normally observed in the default mode regions in healthy subjects performing a cognitive task are not seen in AD patients, or may even be reversed to a paradoxical activation response (Grady et al., 2006; Lustig et al., 2003; Miller et al., 2008a; Otten & Rugg, 2001).
Recent fMRI studies have also revealed alterations in the deactivation pattern in elderly individuals at risk for AD by virtue of their APOE e4 genotype or evidence of MCI. The pattern of fMRI task-induced deactivation seems to be progressively disrupted along the continuum from normal aging to MCI and to clinical AD and more impaired in ε4 carriers than in non-carriers (Persson et al., 2008; Pihlajamäki et al., 2009). It is likely that the pathologically affected MCI or AD brain (Selkoe, 2002; Tanzi, 2005) is no longer capable of “turning off” the default mode activity during focused cognitive processing as it should in order to optimally recruit other networks – such as the hippocampal memory network or the frontoparietal attentional network – for task performance (Eichenbaum, 2000; Mesulam, 1998; Miller et al., 2008a; Weissman et al., 2006). This finding is consonant with recent studies in healthy young and elderly adults demonstrating that the ability to suspend default mode activity during goal-directed cognitive tasks, i.e. to reallocate neurocognitive resources to those brain regions optimal for the task performance, may be critical for successful cognitive performance (Daselaar et al., 2004; Grady et al., 2006; Miller et al., 2008a; Otten & Rugg, 2001; Weissman et al., 2006). Posteromedial cortical regions of the default mode network not only overlap topographically with the pattern of FDG-PET hypometabolism but also with the distribution of the fibrillar Aβ deposition in AD (Buckner et al., 2005). Recent PIB-PET studies, the tracer PIB labeling Aβ plaques (Edison et al., 2007; Klunk et al., 2004), have suggested that the posteromedial cortical areas of high default mode activity may in fact be among the earliest sites of Aβ pathology in AD (Mintun et al., 2006). Thus, functional (as well as structural) imaging studies focusing on this region are pathobiologically very relevant when searching for potential early markers of prodromal AD.
In MCI and AD patients, alterations observed in the fMRI deactivation pattern of the posteromedial cortices (Greicius et al., 2004; Lustig et al., 2003; Petrella et al., 2007a; Petrella et al., 2007b; Pihlajamäki et al., 2008; Rombouts et al., 2005a; Rombouts et al., 2005b) may also reflect remote effects of the MTL pathology and atrophy. The MTL, which is thought to be responsible for the episodic memory deficits observed in amnestic MCI and AD and is known to present the earliest neurofibrillary changes and neuronal and synapse loss, is strongly interconnected to the posteromedial nodes of the default network (Braak & Braak, 1991; Gomez-Isla et al., 1997; Hyman et al., 1984; Insausti et al., 1987; Kordower et al., 2001; Leichnetz, 2001; Suzuki & Amaral, 1994). It is also possible that local structural atrophy of the underlying posteromedial brain regions may explain some of the findings of altered fMRI deactivation (Greicius et al., 2004; Lustig et al., 2003; Petrella et al., 2007a; Petrella et al., 2007b; Pihlajamäki et al., 2008; Rombouts et al., 2005a; Rombouts et al., 2005b).
A more recent imaging approach, that is the functional connectivity MRI (fcMRI), identifies brain systems via intrinsic functional (activity) correlations (Damoiseaux et al., 2006; Fox & Raichle, 2007; Greicius et al., 2003; Greicius & Menon, 2004). Recent fcMRI studies in healthy young subjects have demonstrated the consistency of the resting state networks in the human brain and have also corroborated the findings of altered task-induced deactivation in MCI and AD relative to controls (Celone et al., 2006; Sorg et al., 2007; Supekar et al., 2008; Wang et al., 2007; Zhou et al., 2008). As an example, functional connectivity between the posteromedial and MTL cortices has been reported to be impaired even in MCI subjects relative to healthy elderly controls (Sorg et al., 2007; Zhou et al., 2008). Resting state fcMRI between the MTL and posteromedial cortices has also been demonstrated to reflect underlying structural connectivity as revealed by diffusion tensor imaging. Future studies investigating the relations between, for example, the fMRI task-induced activation / deactivation, resting fcMRI and PIB-PET amyloid imaging findings will further expand our understanding of the role of the Aβ pathology and impaired default mode network function in the pathogenesis and cognitive symptomatology of AD.
There have been a number of promising clinically relevant imaging studies targeting brain functional alterations in AD, MCI and subjects at-risk for AD relative to normal aging. Functional imaging during memory paradigms has shown evidence of specific alterations in the MTL and related whole-brain memory networks that may be able to differentiate the process of very early AD from normal aging. The greatest potential of functional imaging most likely lies in the study of very early stages of dementias, at the point of emerging neuronal dysfunction without significant macroscopic brain atrophy. In the context of early diagnostics of AD, the most interesting and challenging target group to be investigated continues to be the elderly subjects with subtle memory impairment as these subjects would still have preserved brain function and thus scope for therapeutic interventions. Recent revisions of the criteria for AD and MCI strongly emphasize the use of imaging biomarkers in future clinical diagnostics of these disorders. Structural MRI evaluation of the hippocampus is already widely used as a supportive biomarker for AD diagnosis.
The past two decades have seen remarkable advances in our understanding of the pathophysiology of neurodegenerative dementias. As reviewed above, fMRI has many potential advantages in studying patients with cognitive impairment. FMRI can be acquired on a standard clinical magnet during the same session as structural imaging. Because it is non-invasive and subjects are not exposed to radiation, fMRI can be safely repeated many times over the course of longitudinal studies. Perhaps the greatest potential advantage of fMRI is that we can image patients with memory disorders while they are attempting to do the type of cognitive process that is causing them difficulty in their daily living. The use of event-related designs enables investigation of the hemodynamic correlates of specific behavioral events, such as successful long-term memory formation.
There are, however, several challenges in performing fMRI studies in patients with neurodegenerative dementias. It is likely that fMRI will remain quite problematic in examining patients with more severe cognitive impairment. High-field fMRI with optimized imaging parameters can offer spatial resolution as high as in the order of 1 mm, or even less. This is, however, currently not realistic with demented patients as the technique is sensitive to head motion. Inherently, the signal-to-noise ratio of BOLD signal changes between activation and baseline conditions is low, which necessitates repeated measurements and thus leads to relatively long scanning sessions. There is a need for continued technical advances, such as real-time motion correction and high-speed acquisition, to fully realize the potential of this technology in dementia research. Also, if the patients are not able to adequately perform the cognitive task, one of the major advantages of fMRI activation studies is lost. Differences in task performance between patient and control groups complicate data interpretation, as the ability to perform the task may greatly influence the pattern and degree of observed fMRI activity. Resting state fMRI can, however, be performed with less co-operative subjects and is thus better applicable to imaging more severely impaired patients.
It is important to remember that BOLD fMRI is an indirect measure of neuronal activity. The BOLD fMRI signal, and neurovascular coupling linking cellular activity to hemodynamic changes, is likely to undergo changes during healthy aging and during AD-related pathological processes. Some of the changes that may occur even in healthy elderly subjects include, for example, increased atherosclerosis. In AD, the presence of Aβ in the cerebral vasculature, together with altered neurotransmitter activity, impairs synaptic, neuronal and glial function, and may thus lead to attenuated BOLD response. Both increased and decreased BOLD fMRI responses have, however, been reported in MCI and AD and MCI compared to elderly controls, which does not support the view of attenuation of the BOLD signal solely due to vascular reasons (Golby et al., 2005; Grady et al., 2003; Sperling et al., 2003a). The alterations in BOLD activity reported in AD also appear to be quite regionally specific and dependent on the nature of the cognitive task, thus making it relatively unlikely that the changes observed in fMRI studies represent global pathophysiological alterations in neurovascular coupling.
In terms of using fMRI in longitudinal or pharmacological studies, it is critical to complete further validation experiments. The reproducibility of BOLD signal changes within young healthy individuals during memory encoding tasks across separate days is reported to be reasonable (Sperling et al., 2002; Harrington et al., 2006). However, reproducibility of task-related or resting state fMRI activity in older and cognitively impaired subjects has not yet been well established. More longitudinal functional imaging studies are needed to track the evolution of alterations in the fMRI activation / deactivation pattern over the course of the cognitive continuum from healthy aging to AD. It is also important to evaluate the contribution of structural atrophy to changes observed with functional imaging. A combination of structural MRI, fMRI and other functional and molecular imaging techniques such as PIB-PET may eventually serve as a valuable method for the in vivo detection of AD prior to clinical dementia, at the point when disease modifying therapies would likely be most efficacious.
In summary, despite technical challenges, there have been a number of promising fMRI studies in elderly individuals with prodromal AD. Neuroimaging, and in particular BOLD fMRI has produced invaluable information and will likely enable even deeper understanding of the human brain function both in health and disease in the future. Carefully designed future studies using multimodal imaging are hoped to yield us new tools that aid in the early identification of subjects likely to develop dementia. Further longitudinal studies are needed to track the evolution of brain functional alterations over the course of the cognitive continuum from healthy aging to clinical dementias such as AD, and perhaps also the pharmacological efficacy for novel disease-modifying therapies.
The original work from our laboratory described in this chapter was supported by Health Research Council of the Academy of Finland, grant #121038 (HS) and grants #108188 and #214050 (MP), and Kuopio University Hospital EVO grants #477311 and #5772720. We express special gratitude to the subjects who participated in this study.
We live in the “Plastic Age”. From its creation in the early 1870, plastic material has largely contributed to the society development making everyday life easier. Plastic material offer good advantages as it can be customized with specific shapes and chemical and physical properties i.e., elasticity, hardness, lightness, transparency and durability. Due to this, the production has dramatically boosted annual plastic production from 0.5 million tons in the 40s to 550 million tons in 2018 [1]. However, plastics sturdiness presents some negative implications as the increasing rate of plastic consumption worldwide its release in the environment associated with a low degradation rate is resulting in its accumulation in coastal and marine sediments, pelagic and benthic biota from coastal to open ocean areas at each latitude from the poles to the equator. Depending on sources and formation mechanisms plastic fragments are split into “primary” and “secondary”. Primary plastics are resulting from the direct input of freshly manmade emissions, adding new micronized size by-design plastic material to the environment. According to this definition, major sources primary plastics are: (A) polymers intentionally produced and used as such. In this group belong i.e., personal care consumer products, industrial or commercial products and other specialty chemicals with plastic microbeads; (B) inherent collateral products of other industrial activities or (C) plastic sourced as accidental or deliberate spillage i.e., pellets loss from plastic factories and transport. In contrast, secondary plastics are associated as secondary pollution sources where larger plastic items undergo degradation and subsequent fragmentation leads to the formation of smaller plastic pieces as they start to break down by photo-oxidative degradation followed by thermal and/or chemical degradation [2].
\nWhile addressing the comprehension of plastics degradation mechanisms in marine aquatic environments it is useful to divide them into plastics with a carbon-carbon backbone and plastics with heteroatoms in the main chain. Some of the most environmentally recurrent polymers like polyethylene, polypropylene, polystyrene and polyvinylchloride have a pure carbon-based backbone. On the contrary, polyethylene terephthalate and polyurethane plastics have heteroatoms in the main chain. Most packaging materials are made of plastics with a carbon-carbon backbone structure. As they are very often discarded after a short period of time, there is a high potential to observe significant loading in the environment. All these polymers are susceptible to photo-initiated oxidative degradation, which is believed to be their most important abiotic degradation pathway in aerobic outdoor environments. This degradation pathway consists of a complex sequential multi-step process where initially chemical bonds in the main polymer chain are broken down by light, by heat or by a combination of both to produce a free radical formation [3, 4]. Polymer radicals react with oxygen and form a peroxy-radical species. As a side effect, the co-occurring formation of hydroperoxides promotes a further complex pathway of radical reactions leading to significant autoxidation of the target polymer. These processes ultimately lead to chain scission, branching and creation of oxygen-containing functional groups. As the molecular weight of the polymers is reduced, the material becomes fragile and is more vulnerable to fragmentation, which makes a higher surface area reactive to further degradation. Nevertheless, anti-oxidants and stabilizers used as additives inhibit the degradation of the polymer. Thus, degradation rates depend strongly on used additives and plasticizers [4]. In most cases these are well-known toxic chemicals not covalently bonded to the polymer and therefore capable of leaching out from the plastic during the degradation process, and easily enters into the aquatic environment representing a further point of concern for eco-toxicologists. On the other hand, different degradation mechanisms cause degradation of plastics with heteroatoms in the main chain. They show an increased thermal stability compared to polymers with a simple carbon backbone. Under marine environmental conditions the degradation processes of plastics like polyethylene terephthalate (PET) or polyurethane (PU) are normally controlled by hydrolytic cleavage. Similar to carbon-carbon backbone plastic polymers, PET can undergo photo-induced autoxidation via radical reactions leading to the ultimate formation of a carboxylic acid end groups, which show a promoting effect on thermo- as well as photo-oxidative degradation. Weathering of PET in the marine environment occurs mainly by photo-induced oxidation and secondly by hydrolytic degradation processes which cause the yellowing of the polymer. For thermo-oxidative degradation the consequences are an in the content of the some end groups i.e., carboxylic acid as well as a general decrease in molecular weight of the main polymer [4]. Hydrolysis also leads to a reduction in molecular weight and an increase in carboxylic acid end groups. PET is highly resistant to environmental biodegradation because of its compact structure [4]. On the other hand, polyurethane-like compounds show carbon, oxygen and nitrogen in the main chain demonstrating enhanced susceptibility to degradation via photo-oxidation, hydrolysis and biodegradation. Plastic floating on the ocean surface is exposed to moderate temperatures, solar radiation at wavelengths of 300 nm and longer, as well as oxidizing conditions. Since temperatures are moderate, the most important factors initiating abiotic degradation are oxygen and sunlight. According to recent studies, fragmentation patterns first occur at the plastic surface, which is exposed and available for chemical or photo-chemical attack. The process is more efficient with smaller plastic fragments as they show a higher surface to volume ratio [5]. Changes in color and crazing of the surface are the initial visual effects of polymer degradation. Surface cracking makes the inside of the plastic material available for further degradation, which eventually leads to embrittlement and disintegration. Furthermore, almost all commercial plastics include additives. These co-production chemicals embedded in the polymers can also leach into the aquatic environment, which is an additional point of concern. As these substances enhance plastics’ resistance to degradation, it becomes difficult to quantitatively estimate the fragmentation patterns since different plastic products can vary in their composition. On the other hand, additional factors can significantly influence degradation rates as floating plastic may develop biofilms that shield it from UV radiation. The formation of biofilm in plastic microliter collected from the marine aquatic environment has been previously documented worldwide [6, 7, 8]. Such phenomena could lead to a reduction in photo-initiated degradation. So far, there have been very few studies of degradation mechanisms for plastic polymers in the marine environment although some promising early findings have been reported by ongoing joint research initiatives (e.g., JPI-Weather Mic and JPI-PlasTox). The biofilm formation can also affect the vertical distribution of plastic fragments largely affecting their distribution in the water column or in the sedimentary environment. Most synthetic polymers are buoyant in water and substantial quantities of plastic debris that are buoyant enough to float in seawater are transported and potentially washed ashore. The polymers that are denser than seawater tend to settle near the point where they entered the environment; however, they can still be transported by underlying currents. Table 1 resumes the theoretical densities of the most recurring polymers found in the environment. Microbial films rapidly develop on submerged plastics and change their physicochemical properties such as surface hydrophobicity and buoyancy [9, 10]. All in all, plastic debris is a mixture of molecules and chemicals, its size ranging from some meters to a few micrometers and probably nanometers. It is derived from a broad variety of origins, such as fishing gear, nets, bottles, bags, food packaging, taps, straws, cigarette butts and cosmetic microbeads and the associated fragmentation of all of these. Plastic debris has become ubiquitous in all environmental compartments of the marine ecosystem form sediments to sea surface. Thus, the observed loadings floating in the ocean represents only a limited portion of the total input. It has been previously reported that most plastic litter ends up on the seabed with a remaining fraction distributed on beaches or floating on the seawater surface leading one to consider that merely quantifying floating plastic debris may lead to a significant underestimation of the actual amount of plastics in aquatic environments [11].
\nPolymer | \nAbbreviation | \nDensity (g/cm3) | \nApplications | \n
---|---|---|---|
Expanded polystyrene | \nEPS | \n0.01–0.04 | \nBait boxes, floats, cups | \n
Low density polyethylene | \nLDPE | \n0.89–0.93 | \nPlastic bags, bottles, gear, cages | \n
High density polyethylene | \nHDPE | \n0.94–0.98 | \nPlastic bags, bottles, gear, cages | \n
Polypropylene | \nPP | \n0.83–0.02 | \nRope, bottle caps, | \n
Polypropylene terephthalate | \nPET | \n0.96–1.45 | \nBottles, gear | \n
Styrene butadiene rubber | \nSBR | \n0.94 | \nCar tyre | \n
Polyamide | \nPA | \n1.02–1.16 | \nGera, fish farm nets, rope | \n
Polystyrene | \nPS | \n1.04–1.10 | \nContainers, packaging | \n
Polymethyl methacrylate | \nPMMA | \n1.09–1.20 | \nInsulation, packaging | \n
Polyvinylchloride | \nPVC | \n1.16–1.58 | \nFilm, pipe, containers | \n
Polycarbonate | \nPC | \n1.20–1.22 | \nTextiles, leisure boats | \n
Polyurethane | \nPU | \n1.20 | \nInsulation, floats | \n
Alkyd | \nALK | \n1.24–2.10 | \nPaints, packaging | \n
Polyester | \nPES | \n1.24–2.3 | \nTextiles, | \n
Polytetrafluoroethylene | \nPTFE | \n2.1–2.3 | \nPersonal care products | \n
Theoretical densities of the most recurring polymers found in the environment.
Overall ecosystem health can be significantly affected by the accumulation of trash and plastics in our seas. Ingestion of and entanglement in marine debris directly impacts marine life. Laboratory studies provide a strong proof of evidence for the effects of microplastic ingestion observed in organisms collected from the natural environment. Indeed, in laboratories, under natural like conditions, microplastics have been shown to be ingested by amphipods, barnacles, lugworms and bivalves [12, 13, 14]. In the same organisms, the uptake of microplastics caused notable ultrastructural changes in the investigated tissues including histological changes as well as cell functioning impairments [15]. In field observations, the occurrence of MPs in the gastrointestinal tract and gills of pelagic and demersal fish and marine mammals has been documented [16, 17]. Past reports have shown that many marine organisms wrongly identify plastic debris for food. Ingestion of marine debris induce different deleterious effects such as pathological alteration, starvation and mechanical blockages of digestive processes. Furthermore, the interaction of plastic fragments, especially those at micrometric and nanometric scales, with organic pollutants are of importance in relation to environmental contamination and biological effects on organisms in the water column as well as in the sedimentary environment [18, 19]. Hydrophobic pollutants co-occurring in the aquatic environment may in fact adsorb onto MP debris. According to the different sizes, plastic fragments have the potential to transport contaminants more effectively through biological membranes and ultimately inside cells of aquatic organisms. The presence of organic pollutants on marine plastics has been illustrated for a wide range of chemicals in natural aquatic conditions [20, 21]. The exposure routes of organic pollutant-enriched MPs are varied, while the toxicity is largely inversely correlated to the size of the particles, as the smaller the particle the further into the organism it can penetrate releasing toxic chemicals under acidic gut conditions [22]. According to the properties of the adsorbed chemicals, several toxicity mechanisms are represented by increased oxidative stress, genotoxicity, depletion of immune competence, impairment of key cell functioning, loss in reproductive performance, disorders in energy metabolism, and changes in liver physiology [23, 24, 25].
\nDifferent methods have been developed for identifying plastics, including meso, micro and nanoplastics in water, sediments and biota as well as to a lesser extent in soil. The percentage of organic matter (OM) in general as well as some recurring specific macromolecules, such as fats and proteins may hamper the analysis, thus hiding plastic fragments in visual analyses and distort signals in Fourier transformed infrared (FT-IR) and Raman spectroscopy, two of the most frequently used methods for plastic identification [26, 27]. Hence, identifying and quantifying plastic materials in organic matter enriched samples may be a challenge. In sediments, several available protocols recommend a preliminary sorting of plastic size grounding and sieving. After sieving, the mineral phase of soils might be removed easily using density fractionation methods. Different density solutions have been used including NaCl, ZnCl2, NaI and more recently 3Na2WO4 9WO3 H2O to obtain dense floating solutions [28, 29]. However, it has been shown that simple density fractionations will not succeed in separating organic matter from plastic materials in sediments because most of the OM show densities between 1.0 and 1.4 g/cm3, similar to that of several environmentally recurring plastic types like PET, PP, PE and Nylon. Sufficient removal of OM without destroying small plastic polymers is challenging because large parts of OM are refractory. At the same time, polymers show strong sensitivity to acidic or strong oxidizing treatment conditions, which induce permanent modifications (e.g. yellowing), thus hampering their classification by microscope-oriented techniques. To efficiently remove OM, multistep extraction, purification processes based on alkaline treatments possibly combined with multi-enzymatic digestion steps have been suggested for the analyses of biota water or sediments. Enzymatic digestion has been promising for the removal of organic as well as other interferents, such as chitin, agar and lipid enriched samples [27]. Strong alkali digestions have been pointed out as being effective for sediments as well as biological samples, without altering the plastic itself [30]. While on the contrary and as previously mentioned, strong acidic conditions induce partial dissolution of polycarbonate as well as partial digestion of polyethylene and polypropylene [13]. Another largely exploited strategy to remove organic matter relies on the application of concentrated hydrogen peroxide [26]. However, its use must be critically evaluated in terms of digestion conditions as treatments with incubation exceeding 48 h with temperatures exceeding 50C, which may degrade plastic polymers like polyethylene and polypropylene [31]. In this context, some authors have recently suggested an effective combined multistep method based on a sequence of enzymatic digestions followed by a short hydrogen peroxide treatment for the removal of organic matter from complex environmental matrices (e.g., wastewater samples). In summary, several promising methods have been tested for extracting, purifying and pre-concentrating plastic materials from sediments and marine biota, all of them having potential limitations. More research is needed to develop a standard protocol for isolating plastics from a range of different environmental matrices, ideally at low cost and without altering plastic properties.
\nOnce isolated, plastic fragments can be tracked and characterized by different analytical techniques. Some are defined as “surface oriented” methods like Raman spectroscopy, Fourier Transformed Infra-Red (FTIR), Scanning Electron Microscopy/Energy Dispersive X-Ray Spectroscopy (SEM-EDS) and environmental scanning electron microscope (ESEM) with an attached X-ray energy dispersive system (ESEM-EDS). Plastic fragments are visually sorted and analyzed coupled with microscopy. However, as discussed above, the use of strong oxidant/acidic agents applied during the extraction from sometimes complex environmental matrices (e.g., organic matter enriched marine sediments, or fat rich marine biota) may induce alteration in the plastic surface like partial dissolution, yellowing and polymer structure disruption leading to erroneous characterization of microparticles. Furthermore, some compounds of natural origin occurring in marine samples (e.g., chitin) have shown spectroscopic properties similar to those of the most recurrent plastic polymers leading to inaccurate polymer characterizations and overall abundance estimation. In addition, these microscopy-based techniques are time consuming and unable to process large numbers of samples. However, significant advances in the automatic and semi-automatic FTIR spectra recognition have been recently presented as promising time saving solutions (Jes recent paper). Alternatively, promising solutions include the Pyrolysis-gas chromatography in combination with mass spectrometry (Pyr-GC-MS) as well as the Thermogravimetric analysis coupled with mass spectrometry (TGA-MS). Pyr-GC-MS in particular can be used to assess the chemical composition of potential microplastic particles by analyzing their thermal degradation products. The polymer origin of particles is identified by comparing their characteristic combustion products with reference pyrograms of known virgin-polymer samples. Py-GC/MS had the advantage of being able to analyze the polymer type and OPA content in one run without using any solvents and with few background contaminations. Additionally, the Pyr-GC/MS method has an appropriate degree of sensitivity for analyzing plasticizers in microplastic particles with limited sample masses. However, although the pyrolysis-GC/MS approach allows for a good assignment of potential microplastics to polymer type it has the disadvantage of being a “destructive” technique as the sample is burned to obtain the pyrolytic products. Furthermore, due to limitations in the quantity of sample loaded in the pyrolysis cup only particles of a certain minimum size can be processed resulting in a lower size limitation of particles that can be analyzed. Each of these methods have their own limitations and advantages, therefore, their combined use, especially for the analysis of complex environmental samples, is a recommended strategy to reduce the effect of interferents in the analysis and obtain reliable results.
\nWith some of the most significant amounts of solid waste generated annually per person (208–760 kg/year), the Mediterranean Sea is one of the world’s areas most affected by litter [32]. The estimated amount is 62 million of macrolitter items floating on the surface of the whole basin [33]. Litter enters the seas from land-based sources, ships and other infrastructure at sea and can travel long distances before being deposited on the seabed or along the coasts. Mean densities of floating microplastics in the Mediterranean Sea of more than 100,000 items/km2 [34] indicate the importance of this threat for the basin. In this context, the Adriatic Sea represents a hot spot for plastic litter both because of peculiarities in its oceanographic conditions as well as the high degree of anthropogenic pressure related to tourism, artisanal and industrial activities coexisting in a narrow area. The Adriatic Sea is an elongated basin, located in the central Mediterranean, between the Italian peninsula and the Balkans, with its major axis in the NW-SE direction. The northern area is very shallow, gently sloping, with an average depth of about 35 m, while the central part is on average 140 m deep, with the two Pomo depressions reaching 260 m. The northern and central parts of the basin are affected by a great number of rivers along the Italian coast, of which the Po river is the most relevant. River discharge and wind stress are the main drivers of the water circulation. West Adriatic Current (WAC), flowing SE along the western coast, and East Adriatic Current (EAC), flowing NE along the eastern coast are the main currents affecting the Adriatic circulation. There are two main cyclonic gyres, one in the northern part and the other in the south. The Bora wind (from NE) causes free sea surface to rise close to the coast enhancing the WAC and the Sirocco wind (from SE), which is the major wind affecting the Adriatic Sea, leads flood events in the shallow lagoons along the basin coast [35]. A vertical thermohaline front parallel to the coast and extending throughout the water mass, divides the coastal waters from the open sea. This retains the materials flowing from rivers and other water sources within the coastal area. A stratification characterizes the water column separating the warmer surface waters with lower salinity from deeper, colder and more saline ones during summer [35].
\nAcross the Mediterranean, but in the Adriatic Sea in particular, there is a continued demand to increase aquaculture production to fulfill the increasing market demand. Mussels, clams, sea bass and seabream production has become a significant source of regional income. Aquaculture was developed to support consumers’ demand for seafood and the methods of production have continued to expand with the growing consumer market. As the need for fish and mussel aquaculture has increased, the development and expansion of aquaculture facilities in coastal and open water locations has increased accordingly. The expansion of the industry and the diversity of materials used to build and maintain aquaculture systems have paralleled the development of synthetic polymers over recent decades. Synthetic fibers offer greater strength and durability than natural fiber ropes; they are cheap, durable and easier to handle compared to their natural counterparts. Most modern aquaculture activities use plastic-based lines, cages, or nets suspended from buoyant or submergible structures (in part made of plastic) and have nanotech plastic-based biofouling and paint applied. Today, tanks, pens, nets, floats, pontoons as well as the pipes of the fish feed supplying systems are made of plastic materials. All plastic material within an aquaculture site is maintained and controlled for chemical degradation, biofouling and corrosion, and is regularly inspected to ensure strength and stability. In the context of global plastic pollution to the oceans, aquaculture may be a contributor to this. However, the estimation of their contribution remains a knowledge gap and lost or derelict gear as well as other possible plastics emissions from aquaculture can be a locally important contributor especially in coastal areas with intensive activity. New reports also point out a potential micro and nanoplastic contamination in wild and cultured seafood products even if the extent of such phenomena is still unknown. There is also concern regarding fisheries as a source of microplastics to the marine environment because both sectors use plastics that may degrade/fragment into microplastics. The coastal areas of Emilia Romagna and the Croatian coast represent sites of intense mussel and fish aquaculture production with hundreds of tons produced yearly. On the other hand, intense fishing activities coexist with a variety of fishing gear and methods being used in industrial and small-scale fisheries. Fishing gear for capture fisheries includes trawl nets, dredges, surrounding nets, lift nets, seine nets, traps, hook and lines. Nets and floats are made from a range of plastics including PP, PET, NyL, PVC, polyamide (PA) and PS.
\nIn oil and gas exploration, drilling fluids based on plastic microbeads were introduced a decade ago. Teflon strengthened particles have been largely applied for drilling purposes internationally. Despite the use of Teflon and other polymers with specific features being used extensively in production, waste treatment processes are not designed for, and give no mention of how to handle plastic particles, so this has clearly not been addressed as an issue in the past. Therefore, there is a substantial lack of information on potential loadings of microplastics used in this sector. To date, few fragmentary studies have addressed this topic. CEFAS’s report entitled, “The discharge of plastic materials during offshore oil and gas operations” suggests that 532 tons of plastics and 7475 tons of “possible plastics” have been released from the UK offshore oil sector. Although knowledge about microplastic from oil and gas extraction activities is limited, it is very likely they represent a potential contributor in the emissions of plastics in aquatic environments, including microplastic and fibers, emphasizing that it should certainly be considered in future source assessments. The mapping of the distribution of rigs and platforms in the Adriatic Sea where tens of oil fields with hundreds of medium sized oil rigs occur, may provide estimations about the geographic distribution of the potential input related to these industrial activities.
\nShips and maritime installations contain many plastic items, like insulation, coating, electrical wiring, furniture and textiles. Ideally, installations should be stripped of all potentially hazardous materials before dismantling. However, plastics items are not identified in the list of harmful materials. Therefore, polymer-based coatings and several kinds of insulation and wiring are rarely stripped.
\nThe distribution of products can contribute to the release of plastics in the environment. Most transferring of stock will occur alongside the transport infrastructure network. However, even if recognized as an important source of pollution, the contribution from releases during transportation, and as is the case for shipping, a map of the main transportation network including roads and harbors is still lacking. Systematic mapping in the Adriatic context has been suggested to improve the understanding of the areas where potential inputs can occur, providing a proxy for the potential intensity for release. The Adriatic Ship Traffic Database also contains information on ports in the Adriatic Sea that could be used to gauge the intensity of port activity to identify which of the port areas could potentially be receiving the largest inputs. Furthermore, the cruise ship industry is pointed out as a significant contributor to the problem of plastic pollution in the Adriatic sea. However, very limited data are available and no specific regulations in place for their plastic waste management and/or assessment of their environmental impact [36].
\nAt a global level, the major challenge to tackle the input of plastic debris from land into the ocean is the lack of adequate waste management in coastal regions with a high and growing population density. Due to a generally high population density in coastal areas of the Adriatic, the pressure resulting from land-based inputs should be relatively high overall. Given such levels of anthropogenic pressure, the lack of, or deficient local waste management systems may lead to locally high inputs linked to industrial or domestic waste management.
\nThere are no studies looking specifically at the leakage and marine input of plastic debris linked to these waste management systems, but ongoing work to quantify and characterize beach litter here points toward potential input from inadequate waste management on the eastern shores of Croatia where the islands of the Quarnero natural park present high loadings of plastic fragments. The composition of the waste accumulated resembles the composition of surveys carried out in the mid-Adriatic region where influence from higher population densities along the coastline is being registered. In addition, a study looking into microplastics near Venice has detected exceptionally high concentrations of small plastic fragments and microplastics in a nearby sandy beach [52]. Though not specified in this report, this exceptionally high concentration of microplastics, including large amounts of plastic fibers and film, could be linked to this location being close to the harbor as well as the lack of waste management facilities. To gain further insight into the potential release of plastics associated with waste management, it would be useful to map the distribution of population density as well as the location of urban agglomerations and settlements as this information will provide an indication of potential localized points of release of plastic waste into the environment. This kind of information is readily available at a sufficient resolution to allow identification of the areas within the Adriatic Sea that need more attention to this potential source of plastic pollution.
\nA rough estimation predicts that 70–80% of marine litter, composed primarily of plastics, originate from inland sources, ending in rivers and oceans. However, inland deposition of MP has not been investigated thoroughly. Potential sources include sewage treatment plants (STPs) and runoff from urban, agricultural, tourist, and industrial areas. As the retention capacity of conventional wastewater treatment processes to MPs appears to be variable in both magnitude and specificity, a characterization of MP emission by STPs and other sources is needed to map major sources of freshwater and terrestrial MPs. A relevant input to the terrestrial ecosystem is by fertilizers obtained by processing sewage sludge, as it typically contains more MPs than liquid effluents. Such fertilizers are frequently used in agriculture, implying a potential accumulation of plastic particles in the soil with continued use, and a systematic examination and quantification has been addressed by several research groups around the world. However, due to runoff, deposited plastic items are most likely transported to rivers and other waterways and ultimately discharged into estuarine and marine environments.
\nThe north of Italy and Croatia represent areas of intense horticultural activities where the agricultural practice of plastic mulching is prevalent. Plastic sheets are used to cover soil in order to preserve moisture, improve fertility and reduce weed infestation. Very often, fragments of plastic films are left behind after use and may accumulate in the soil, further fragmenting to produce nanometric particles. It has been estimated that 125–850 tons of microplastic per million inhabitants are added each year to agricultural soils in Europe, with an annual total of 63,000–430,000 tons of microplastic added to European farmlands. The northern part of Italy and Croatia is an area of significant agricultural and horticultural activities, therefore representing a potential hot spot for the release of plastic fragments in the terrestrial ecosystem. However, due to runoff phenomena these plastic items are most likely transported to rivers and other waterways and ultimately discharged into the estuarine and marine environments.
\nThe first pilot studies of microplastic abundance in confined areas of heavily populated areas like the Oslo fjord noted that a large fraction of particles may be related to city dust (e.g. asphalt and car tires). City dust in urban runoff is known as a significant source of pollution to waterways. Plastics, such as styrene-butadiene, styrene-ethylene-butylene-styrene copolymer, are also used in road materials to make the asphalt more elastic [37]. Another potential contributor to the emissions of plastic fragments is road marking paint as these paints have a variable fraction (1–10%) of thermoplastic component (e.g. styrene-isoprene-styrene, ethylene-vinyl acetate, polyamide and acryl-monomer). On the other hand, the tread of car tires is largely based on styrene-butadiene rubber, a synthetic polymer formulation. Therefore, road dust entering the sea through air or storm water carries a significant fraction of microplastic from road materials, marking paint and car tires.
\nThe description and understanding of the pathways of the entry of marine plastic pollution into the Adriatic Sea is a central element in tracing the pollution back to its sources and developing effective plastic pollution preventing policies. A complete understanding of the input of plastic pollution into the aquatic environment needs to consider the source sectors and the mechanisms of transportation, distribution and partition through different environmental matrices. If the release occurs in the terrestrial environment, rivers and wind or atmospheric circulation constitute the logic pathways. When considering the presence of plastic debris and microplastics in a part of the global Mediterranean Sea there is a need to consider the transfer of marine plastic pollution into the relevant part of the large water bodies through the regional circulation pathway like the Adriatic Sea. The understanding of the input through these pathways is crucial in gauging the relative importance of local sea-based or coastal sources versus remote sources within the Arctic watershed or from other parts of the ocean.
\nThe Adriatic Sea has a limited watershed. The largest rivers in the area are mostly located in the northern sector and include the Po, Adige, Tagliamento, and Arsa rivers. In terms of discharge, the Po River has the largest discharge with 1540 m3/s followed closely by the Adige River with 235 m3/s. The Po Basin is home to some 14 million people and extends over 24% of Italy’s territory. The Po catchment is densely populated and subjected to high anthropogenic pressure heavily anthropized. Indeed, it represents the largest cultivated area in Italy and accounts for one third of national’s agricultural production. The area account also for one of the highest concentrations of economic activities. Such massive river discharges make terrestrial influences particularly strong in the Adriatic Sea. However, to date there is no monitoring of the flux of plastics from rivers into the Adriatic Sea and though it has been identified as a possible pathway, the contribution of riverine discharge to plastic input is expected to be high because these rivers flow through densely populated and anthropized watersheds.
\nIt has been speculated that at the global level much less plastic debris is transported by wind than by rivers [38, 39]. However, wind transport of plastic debris may be significant, particularly in coastal areas dominated by strong periodic winds. Wind may be a significant contributor in lightweight debris distribution. During intense storms wind can mobilize debris that would not normally be available for transport and carry it directly into rivers and the sea. Wind-blown litter is likely to be considerable as the Adriatic Sea is characterized by periodically windy shorelines. Atmospheric circulation has been proven to provide an efficient pathway for the transportation of floating microfibers and small plastic particles in the Mediterranean Sea as well as in other areas [33, 40]. Furthermore, some preliminary transport models tailored to the Adriatic oceanographic conditions, considering the contribution of waves and wind in the surface plastic distribution, define the Adriatic Sea as a highly “dissipative” system with respect to floating plastics with a calculated half-life of floating condition of 43.1 days [41, 42]. The authors conclude by pointing out that by construction the Adriatic coastline may be responsible for the main sink of floating plastic debris.
\nThe contribution of inputs through the movement of marine water masses by currents also needs to be considered in the global distribution model. The Adriatic region is poorly connected to the Mediterranean through the southern edges of the Otranto strait and the Ionian Sea exchanging with the Mediterranean Sea. The exchange of water, and possibly any moving plastic pollution, from and to the Mediterranean Sea has recently been addressed by the modeling work of Liubartseva et al. [40] and partially by the results of Pasquini et al., [40] which pointed out the formation of an accumulation zone corresponding to the three well known gyres located northside, central and in the southern sector of the Adriatic Sea.
\nSome key research projects have recently addressed the need of defining the baseline levels of litter (macro-, meso- and microplastics) in the intertidal areas of beaches within the Adriatic Sea. Blašković et al. [41] investigated the occurrence of plastic debris in several sites of the Natural Park of Telaščica (Croatia). In all analyzed sites, fibers were the most recurring shape (90%) within the identified plastic debris while films where the second most common plastic fragment observed (7%) followed by pellet, foams, granules and unrecognized plastic pieces. Most of the plastic debris belonged to the size fraction from 1 mm and 64 μm (88%) followed by the fraction between 1 and 2 mm (11%). These results confirm previous characterization efforts of Laglbauer et al. [43] in six Slovenian beaches located in the gulf of Trieste (North-East Adriatic Sea). Within this assessment the authors sorted out a total of 5870 macro-debris units, yielding a median density of 1.25 items/m2. The detailed analyses of the processed samples revealed a dominant secondary microplastics source being fibers the 85% of the total observed plastics and a number of 155 particles m2 in the infralittoral zone, and 133 particles m2 on the shoreline. On the Adriatic beaches surveyed, plastic dominated in terms of abundance, followed by paper and other groups. The average density was 0.2 litter items m2, but at one beach it raised to 0.57 items m2. Among plastic, cigarette butts were the most frequently found type of litter, and other plastic items with the highest occurrence were: small fragments, bottles and bottle caps, cutlery, and mesh bags. Their presence is a good indicator of pollution from beach users [44]. Most of the beached marine litter are from land-based sources, but with different sources and contributors. The main source of litter was primarily touristic activities, accounting for 37.9% of found litter which is lower than r the Mediterranean average (52%; [45, 46]). Filter cigarette were the second litter origin, but with a value (25.5%) lower than indicated for the Mediterranean (40%) [44]. The high percentages of in situ deposited litter found in the investigated sites are caused by the high number of visitors, more than 700,000 annually mainly during the touristic season (see i.e.,
Few studies have addressed the occurrence of floating plastic debris in the surface water of the Adriatic Sea. Suaria et al. [33] reported by a larger study addressing the Mediterranean Sea and partially the Adriatic sector a clear prevalence of smaller particles. Quantitative estimations collected by a 400 μm net mesh pointed out values ranging from 0.4 ± 0.7 to 1.0 ± 1.8 items/m3. The overall result the study pointed out that, within a total no. of 14,106 scored particles, 26% of all counted particles were smaller than 300 μm while 51% were smaller than 500 μm being the mean abundance of these meso-particles of 0.016 ± 0.028 particles/m2. PE was the predominant form with an overall frequency of 52%, followed by PP (16%) and synthetic paints (7.7%). Polyamides (PA) accounted for 4.7% of all categorized particles which accounted alone for 2%), while PVC, PS and PVA represented equally contributed with 3% of the total. Other less frequent polymers (<1%) included: PET, polyisoprene, poly(vinyl stearate) (PVS), ethylene-vinyl acetate (EVA) and cellulose acetate. Noteworthy the authors concluded that the composition of western Mediterranean samples was dominated by low-density polymers such as polyethylene and polypropylene while the processed Adriatic samples instead were more heterogeneous and rather characterized by a higher presence of paint chips, PS, PVC, PVA and PAs. Within the “Derelict Fishing Gear Management System project – “DeFishGear” project co-funded by IPA-Adriatic Cross-border Cooperation Programme and the European Union, 120 visuals transect surveys were conducted during three cruises, covering a total length of 922.2 km [47]. A total of 1364 macro marine debris objects were observed floating on the Adriatic. The densities of the recorded floating debris were 5.66 items/km2. The authors estimated that the observed floating marine debris was mostly originated from coastal segments close the high-density population cities and major rivers and transported by cyclonic surface circulation until either stranding. They calculated an average time from source to the sighting point of 22.8 days. These outcomes support Carlson and co-workers [48] previous assessment where an average residence time of 22.9 days but with also an average transit times of 20–60 days from a coastal region in the northwest Adriatic to a coastal region in the southwest [47]. The transport pathways, residence times, and probable sources and sinks identified further support with previous studies of the Adriatic Sea surface circulation and marine debris published by Liubartseva et al., [40].
\nData regarding macro- and mesolitter on the sea-floor in the Adriatic Sea are also available from the “SoleMon” Project (Solea Monitoring—Rapido trawl survey in the Northern Adriatic Sea), carried out since 2005 in the Northern and Central Adriatic Sea [49]. Plastic litter was divided by the authors in three sub-categories based on its source: fishing nets, mussel culture debris and other plastic e.g., bottles, plastic glasses, bags. Lost fishing nets and mussel culture debris accounted for 50% of the overall plastic litter collected over the investigated period. The remaining plastic comprised a wide range of objects such as garbage bags, shopping bags, cups, bottles, food packaging, dishes, other kitchen stuffs and industrial packaging [40, 48]. Results of this study indicated that the largest amount of mussel culture debris was found close to the coast and its distribution was constant over the years. These nets might have been accidentally lost/abandoned at sea during the collection and preparation of the product [50]. In the meantime, the fishing nets were found mainly close to the coast within 3 nm. This distribution was explained as fishing nets were mainly set-nets used by small scale fisheries that usually fish not further than 3 nm where there is not trawl fishing that can destroy these nets. A significant contribution of plastic litter found close to the coast was represented by food packaging, plastic bags, bottles and dishes or kitchen tools. The land origin is due to the municipal solid waste [48]. The authors concluded considering that the distribution varied among the years, but the occurrence was mostly related to both the close position of the sampling site to large cities along the coast, where the population density increases during the touristic season as well as the contribution of river [40, 50, 51]. As regards the microliter in the sedimentary environment, a preliminary assessment of microplastics in marine sediments along a coast- off-shore transect in the Central Adriatic was performed by Munari et al. [44]. Plastic fragments recollected from 64 samples were scored, weighted and identified by FTIR. Microplastics ranging 1–30 mm were found in all analyzed samples. The most recurring shapes were filaments-like (69.3%), followed by fragments-like (16.4%), and film-like (14.3%). In term of size distribution, plastic fragments in a range from 1 to 5 mm accounted for 65.1% of debris, while larger fragments (5–20 mm) contributed with the 30.3% of total amount, while larger fragments >20 mm represented the 4.6% of total. Six were the most recurring polymer types: nylon, polyethylene and ethylene vinyl alcohol copolymer. Furthermore, sediments from several sampling sites located in Italy, Slovenia, Croatia, and Greece were also analyzed for plastic debris content by the “DeFishGear” project. Plastic fragments in beach sediments were ranked into large sized particles (1–5 mm) and small microplastic particles (<1 mm). In general, microplastic from 1 to 5 mm ranged from 11 to 710 items/m2. On the other hand, the fraction of smaller size scored from 70 to 6724 items/kg of dry sediments. The mean concentration for all Adriatic region was calculated as 113 ± 101 items/kg for the larger sized fragments and 1133 ± 1271 items/kg of dry sediments for the smaller ones. In detail, the selected Croatian beaches showed considerably greater presence of smaller microplastic per kg of sediment with value of approx. 227 items/kg of sediment while the larger sized fragments sored values approx. Ten times lower (17–28 items/kg of dry sediments). The composition of sorted fragments <1 mm showed the prevalence of plastic fragments as fragments represented approx. 70% of the total while filaments represented the left 29% of the total while a limited amount (1.8 and 0.9%) were film and foams. The chemical characterization of microplastic of the larger particles was performed on foams, pellets, fragments and filaments, while filaments and films were analyzed among the smaller sized particles. Beside the PE and PP in a few percent also PA, PET, PES, PS, PO, nylon and acrylic fibers were present among larger particles, while among the smaller viscose was detected. In the Greek sector data were obtained from three sites: the Halikounas, Issos and Acharavi beaches. The mean concentration of 1–5 mm sized debris varied from 68 items/m2 (Halikounas) to 58 items/m2 (Acharavi) while the small sized fraction of Ø > 1 mm showed values from 19 to 7 items/m2 respectively for Halikounas and Acharavi. The most abundant categories on Halikounas beach were fragments and foam, while on the contrary pellets were the most abundant in Issos and Acharavi beaches. Chemical characterization of fragments, for Halikounas beach were done being both PE and PP the most recurring polymers in the larger particles while PP was the most occurring polymer in the smaller size fraction. The same project also addressed the occurrence in the Italian sector. High amount of small microplastic particles (<1 mm), up to 2526 items/kg of sediment, was found in the Cesenatico area. In the meantime, a limited amount corresponding to 0.56–1.02 items/kg of large particles (1–5 mm) were reported. Overall, 73% of the small microplastic particles were characterized by fragments while the remaining 26% as filaments. On the other hand, the large microplastic particles had different amount of all categories; however, fragments resulted the most abundant category (44%). The chemical identification showed PE as the most abundant material, followed by PP, PO, PES, PS and PAN. In the Slovenian coastline the selected sampling site showed a higher abundance of small microplastic particles (615 items/kg) respect of large microplastic particles (516 items/kg). In detail, the analysis of the small size fraction reported filaments being the predominant type of the microplastic composition, with representation of approx., 76% of the total. The second most common type of microplastic category were fragments and the third were films, with occurrence high as 9.5%. The chemical identification pointed out PE as the most recurring polymer type in the analyzed sediment samples, followed by PP, PET and PVC. Finally, Vianello and co-workers investigated the Venice Lagoon, a fragile estuarine ecosystem dominated by diversified anthropogenic activities, suspected to be a hot spot of plastic debris contamination [53]. Plastic debris of ≤1 mm or less was investigated in sediments collected from 10 sites chosen in shallow areas. Total abundances of plastic fragments varied from 2175 to 672 items/kg with higher concentrations generally found in the inner parts of the Lagoon. PE, PP, ethylene propylene (PEP), polyester (PEst), polyacrylonitrile (PAN), PS, alkyd resin (Alkyd), PVC, polyvinyl alcohol (PVOH) and NyL were identified. PE and PP were the most recurring polymer in the investigated samples which accounted for more than 82% of the total detected plastic debris in the whole sampling area. Among all classified shapes, irregular fragments accounted of the 87% of the total while films (2%) and pellets/granules (1%) were only occasionally recognized [54].
\nThe first report on the harmful effects of plastic debris ingestion on marine species in the Adriatic Sea was published in 1999 [55]. A dead dolphin S. coeruleoalba with the stomach occluded by different kinds of plastic materials was found near the island Krk, in the North Adriatic Sea. A following study on the logger head sea turtles, C. caretta, revealed a percentage of 35.2% of turtles sampled in the eastern Adriatic Sea were affected by plastic debris [55]. Occurrence of MPs in the gastrointestinal tract and gills of pelagic and demersal fish and marine mammals have been reported [56]. Few plastic debris accumulation studies have been performed in the Adriatic Sea. Pellini et al. [57] aimed at characterizing the occurrence, amount, typology of microplastic litter in the gastrointestinal tract of a benthic fish, S. solea, in the northern and central Adriatic Sea. The digestive tract contents of over 500 individuals were collected from 60 sampling sites and examined for microplastics. These were recorded in 95% of sampled fish, with more than one microplastic item found in around 80% of the examined specimens. The most commonly found polymers were PVC, PP, PE, polyester (PES) and PA. In details, 72% of the total classified plastic debris were fragments and 28% were identified as fibers. The mean number of ingested microplastics was 1.6–1.7 items/fish. PVC and PA showed the highest densities in the northern Adriatic Sea, both inshore and off-shore while PE, PP and PET were more concentrated in coastal areas with the highest values offshore from the port of Rimini. These results confirm previous observations of Avio and co-workers [13] in various fish species collected along the Adriatic Sea. FTIR analyses indicated PE as the predominant polymer (65%) in the stomach of fish. More than 100 fish representatives of five commercial species like S. pilchardus, S. acanthias, M. merlucius, M. barbatus C. lucernus were collected from the Central and North Adriatic Sea. The mean number of ingested microplastics was 1.0–1.7 items/fish. In details, the shape of the plastic debris observed in the stomachs of the investigated samples was mostly fragments and line followed by film and pellet. The 18% of extracted microplastics exhibited the larger size class (from 5 to 1 mm), 43% was between 1 and 0.5 mm, 23% between 0.5 and 0.1 mm, and the 16% lower than 0.1 mm. The chemical characterization pointed out that approximately 65% of analyzed plastic fragments were PE, followed by PET, PS, PVC, Nylon and PP. These early findings suggest the possible accumulation of plastic debris through the food web. Despite of some recent findings point out that at the bottom of the food pyramid, filter feeders, such as mussels can ingest and incorporate MPs in their tissues [58], more research is needed to unveil the abundance, distribution and polymeric composition of plastic debris in marine organisms at different levels ecological web in areas like the Adriatic Sea were multiple anthropogenic activities coexist.
\nThe few available studies in the area prove the ubiquity of plastic pollution in the Adriatic Sea. The peculiar oceanographic conditions as well as the high levels of plastic debris recorded in all investigated matrices tend to classify such enclosed area as a hot spot of plastic contamination. Despite the distribution and circulation models appear to accurately estimate fluxes and final fate of marine plastic debris, sinks, sources, fate and residence times of different polymers at sea are the knowledge gaps that need to be addressed in the future to provide concrete info to support concrete actions toward plastic contamination reduction and remediation solutions.
\nThe authors wish to thank The International Research Institute of Stavanger and the National Research Council of Italy- Institute of Marine Science for technical assistance and financial support to publish this work.
\nThe authors declare no conflict of interest.
IntechOpen books are indexed by the following abstracting and indexing services:
",metaTitle:"Indexing and Abstracting",metaDescription:"IntechOpen was built by scientists, for scientists. We understand the community we serve, but to bring an even better service to the table for IntechOpen Authors and Academic Editors, we partnered with the leading companies and associations in the industry and beyond.",metaKeywords:null,canonicalURL:"/page/indexing-and-abstracting",contentRaw:'[{"type":"htmlEditorComponent","content":"Clarivate Web Of Science - Book Citation Index
\\n\\nCroatian Library (digital NSK)
\\n\\nOCLC (Online Computer Library Center) - WorldCat® Digital Collection Gateway
\\n\\n\\n\\n
\\n"}]'},components:[{type:"htmlEditorComponent",content:'
Clarivate Web Of Science - Book Citation Index
\n\nCroatian Library (digital NSK)
\n\nOCLC (Online Computer Library Center) - WorldCat® Digital Collection Gateway
\n\n\n\n
\n'}]},successStories:{items:[]},authorsAndEditors:{filterParams:{sort:"featured,name"},profiles:[{id:"126408",title:"Prof.",name:"A",middleName:null,surname:"Chaves",slug:"a-chaves",fullName:"A Chaves",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:{name:"Universidade Federal do Ceará",country:{name:"Brazil"}}},{id:"116458",title:"Prof.",name:"A. A.",middleName:null,surname:"Minzoni",slug:"a.-a.-minzoni",fullName:"A. A. Minzoni",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:{name:"National Autonomous University of Mexico",country:{name:"Mexico"}}},{id:"105746",title:"Dr.",name:"A.W.M.M.",middleName:null,surname:"Koopman-van Gemert",slug:"a.w.m.m.-koopman-van-gemert",fullName:"A.W.M.M. Koopman-van Gemert",position:null,profilePictureURL:"https://mts.intechopen.com/storage/users/105746/images/5803_n.jpg",biography:"Dr. Anna Wilhelmina Margaretha Maria Koopman-van Gemert MD, PhD, became anaesthesiologist-intensivist from the Radboud University Nijmegen (the Netherlands) in 1987. She worked for a couple of years also as a blood bank director in Nijmegen and introduced in the Netherlands the Cell Saver and blood transfusion alternatives. She performed research in perioperative autotransfusion and obtained the degree of PhD in 1993 publishing Peri-operative autotransfusion by means of a blood cell separator.\nBlood transfusion had her special interest being the president of the Haemovigilance Chamber TRIP and performing several tasks in local and national blood bank and anticoagulant-blood transfusion guidelines committees. Currently, she is working as an associate professor and up till recently was the dean at the Albert Schweitzer Hospital Dordrecht. She performed (inter)national tasks as vice-president of the Concilium Anaesthesia and related committees. \nShe performed research in several fields, with over 100 publications in (inter)national journals and numerous papers on scientific conferences. \nShe received several awards and is a member of Honour of the Dutch Society of Anaesthesia.",institutionString:null,institution:{name:"Albert Schweitzer Hospital",country:{name:"Gabon"}}},{id:"90116",title:"Dr.",name:"Aaron",middleName:null,surname:"Flores-Gil",slug:"aaron-flores-gil",fullName:"Aaron Flores-Gil",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:{name:"Autonomous University of Carmen",country:{name:"Mexico"}}},{id:"83089",title:"Prof.",name:"Aaron",middleName:null,surname:"Ojule",slug:"aaron-ojule",fullName:"Aaron Ojule",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:{name:"University of Port Harcourt",country:{name:"Nigeria"}}},{id:"295748",title:"Mr.",name:"Abayomi",middleName:null,surname:"Modupe",slug:"abayomi-modupe",fullName:"Abayomi Modupe",position:null,profilePictureURL:"https://mts.intechopen.com/storage/users/no_image.jpg",biography:null,institutionString:null,institution:{name:"Landmark University",country:{name:"Nigeria"}}},{id:"119935",title:"Prof.",name:"Abbas",middleName:null,surname:"Dandache",slug:"abbas-dandache",fullName:"Abbas Dandache",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:{name:"Universidad Politécnica del Valle de México",country:{name:"Mexico"}}},{id:"94191",title:"Prof.",name:"Abbas",middleName:null,surname:"Moustafa",slug:"abbas-moustafa",fullName:"Abbas Moustafa",position:null,profilePictureURL:"https://mts.intechopen.com/storage/users/94191/images/96_n.jpg",biography:"Prof. Moustafa got his doctoral degree in earthquake engineering and structural safety from Indian Institute of Science in 2002. He is currently an associate professor at Department of Civil Engineering, Minia University, Egypt and the chairman of Department of Civil Engineering, High Institute of Engineering and Technology, Giza, Egypt. He is also a consultant engineer and head of structural group at Hamza Associates, Giza, Egypt. Dr. Moustafa was a senior research associate at Vanderbilt University and a JSPS fellow at Kyoto and Nagasaki Universities. He has more than 40 research papers published in international journals and conferences. He acts as an editorial board member and a reviewer for several regional and international journals. His research interest includes earthquake engineering, seismic design, nonlinear dynamics, random vibration, structural reliability, structural health monitoring and uncertainty modeling.",institutionString:null,institution:{name:"Minia University",country:{name:"Egypt"}}},{id:"84562",title:"Dr.",name:"Abbyssinia",middleName:null,surname:"Mushunje",slug:"abbyssinia-mushunje",fullName:"Abbyssinia Mushunje",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:{name:"University of Fort Hare",country:{name:"South Africa"}}},{id:"202206",title:"Associate Prof.",name:"Abd Elmoniem",middleName:"Ahmed",surname:"Elzain",slug:"abd-elmoniem-elzain",fullName:"Abd Elmoniem Elzain",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:{name:"Kassala University",country:{name:"Sudan"}}},{id:"98127",title:"Dr.",name:"Abdallah",middleName:null,surname:"Handoura",slug:"abdallah-handoura",fullName:"Abdallah Handoura",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:{name:"École Supérieure des Télécommunications",country:{name:"Morocco"}}},{id:"91404",title:"Prof.",name:"Abdecharif",middleName:null,surname:"Boumaza",slug:"abdecharif-boumaza",fullName:"Abdecharif Boumaza",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:{name:"Abbès Laghrour University of Khenchela",country:{name:"Algeria"}}}],filtersByRegion:[{group:"region",caption:"North America",value:1,count:5766},{group:"region",caption:"Middle and South America",value:2,count:5228},{group:"region",caption:"Africa",value:3,count:1717},{group:"region",caption:"Asia",value:4,count:10370},{group:"region",caption:"Australia and Oceania",value:5,count:897},{group:"region",caption:"Europe",value:6,count:15791}],offset:12,limit:12,total:6959},chapterEmbeded:{data:{}},editorApplication:{success:null,errors:{}},ofsBooks:{filterParams:{topicId:"15"},books:[{type:"book",id:"10676",title:"Graph Theory",subtitle:null,isOpenForSubmission:!0,hash:"900c60742d224080732bd16bd25ccba8",slug:null,bookSignature:"Dr. Harun Pirim",coverURL:"https://cdn.intechopen.com/books/images_new/10676.jpg",editedByType:null,editors:[{id:"146092",title:"Dr.",name:"Harun",surname:"Pirim",slug:"harun-pirim",fullName:"Harun Pirim"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"10677",title:"Topology",subtitle:null,isOpenForSubmission:!0,hash:"85eac84b173d785f989522397616124e",slug:null,bookSignature:"",coverURL:"https://cdn.intechopen.com/books/images_new/10677.jpg",editedByType:null,editors:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"10678",title:"Biostatistics",subtitle:null,isOpenForSubmission:!0,hash:"f63db439474a574454a66894db8b394c",slug:null,bookSignature:"",coverURL:"https://cdn.intechopen.com/books/images_new/10678.jpg",editedByType:null,editors:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}}],filtersByTopic:[{group:"topic",caption:"Agricultural and Biological Sciences",value:5,count:17},{group:"topic",caption:"Biochemistry, Genetics and Molecular Biology",value:6,count:4},{group:"topic",caption:"Business, Management and Economics",value:7,count:2},{group:"topic",caption:"Chemistry",value:8,count:8},{group:"topic",caption:"Computer and Information Science",value:9,count:6},{group:"topic",caption:"Earth and Planetary Sciences",value:10,count:7},{group:"topic",caption:"Engineering",value:11,count:18},{group:"topic",caption:"Environmental Sciences",value:12,count:2},{group:"topic",caption:"Immunology and Microbiology",value:13,count:3},{group:"topic",caption:"Materials Science",value:14,count:5},{group:"topic",caption:"Mathematics",value:15,count:1},{group:"topic",caption:"Medicine",value:16,count:24},{group:"topic",caption:"Neuroscience",value:18,count:2},{group:"topic",caption:"Pharmacology, Toxicology and Pharmaceutical Science",value:19,count:3},{group:"topic",caption:"Physics",value:20,count:3},{group:"topic",caption:"Psychology",value:21,count:4},{group:"topic",caption:"Robotics",value:22,count:1},{group:"topic",caption:"Social Sciences",value:23,count:3},{group:"topic",caption:"Technology",value:24,count:1},{group:"topic",caption:"Veterinary Medicine and Science",value:25,count:1}],offset:12,limit:12,total:3},popularBooks:{featuredBooks:[{type:"book",id:"9385",title:"Renewable Energy",subtitle:"Technologies and Applications",isOpenForSubmission:!1,hash:"a6b446d19166f17f313008e6c056f3d8",slug:"renewable-energy-technologies-and-applications",bookSignature:"Tolga Taner, Archana Tiwari and Taha Selim Ustun",coverURL:"https://cdn.intechopen.com/books/images_new/9385.jpg",editors:[{id:"197240",title:"Associate Prof.",name:"Tolga",middleName:null,surname:"Taner",slug:"tolga-taner",fullName:"Tolga Taner"}],equalEditorOne:{id:"186791",title:"Dr.",name:"Archana",middleName:null,surname:"Tiwari",slug:"archana-tiwari",fullName:"Archana Tiwari",profilePictureURL:"https://mts.intechopen.com/storage/users/186791/images/system/186791.jpg",biography:"Dr. Archana Tiwari is Associate Professor at Amity University, India. Her research interests include renewable sources of energy from microalgae and further utilizing the residual biomass for the generation of value-added products, bioremediation through microalgae and microbial consortium, antioxidative enzymes and stress, and nutraceuticals from microalgae. She has been working on algal biotechnology for the last two decades. She has published her research in many international journals and has authored many books and chapters with renowned publishing houses. She has also delivered talks as an invited speaker at many national and international conferences. Dr. Tiwari is the recipient of several awards including Researcher of the Year and Distinguished Scientist.",institutionString:"Amity University",position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"3",totalChapterViews:"0",totalEditedBooks:"1",institution:{name:"Amity University",institutionURL:null,country:{name:"India"}}},equalEditorTwo:{id:"197609",title:"Prof.",name:"Taha Selim",middleName:null,surname:"Ustun",slug:"taha-selim-ustun",fullName:"Taha Selim Ustun",profilePictureURL:"https://mts.intechopen.com/storage/users/197609/images/system/197609.jpeg",biography:"Dr. Taha Selim Ustun received a Ph.D. in Electrical Engineering from Victoria University, Melbourne, Australia. He is a researcher with the Fukushima Renewable Energy Institute, AIST (FREA), where he leads the Smart Grid Cybersecurity Laboratory. Prior to that, he was a faculty member with the School of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA, USA. His current research interests include power systems protection, communication in power networks, distributed generation, microgrids, electric vehicle integration, and cybersecurity in smart grids. He serves on the editorial boards of IEEE Access, IEEE Transactions on Industrial Informatics, Energies, Electronics, Electricity, World Electric Vehicle and Information journals. Dr. Ustun is a member of the IEEE 2004 and 2800, IEC Renewable Energy Management WG 8, and IEC TC 57 WG17. He has been invited to run specialist courses in Africa, India, and China. He has delivered talks for the Qatar Foundation, the World Energy Council, the Waterloo Global Science Initiative, and the European Union Energy Initiative (EUEI). His research has attracted funding from prestigious programs in Japan, Australia, the European Union, and North America.",institutionString:"Fukushima Renewable Energy Institute, AIST (FREA)",position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"1",totalChapterViews:"0",totalEditedBooks:"0",institution:{name:"National Institute of Advanced Industrial Science and Technology",institutionURL:null,country:{name:"Japan"}}},equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"10065",title:"Wavelet Theory",subtitle:null,isOpenForSubmission:!1,hash:"d8868e332169597ba2182d9b004d60de",slug:"wavelet-theory",bookSignature:"Somayeh Mohammady",coverURL:"https://cdn.intechopen.com/books/images_new/10065.jpg",editors:[{id:"109280",title:"Dr.",name:"Somayeh",middleName:null,surname:"Mohammady",slug:"somayeh-mohammady",fullName:"Somayeh Mohammady"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9644",title:"Glaciers and the Polar Environment",subtitle:null,isOpenForSubmission:!1,hash:"e8cfdc161794e3753ced54e6ff30873b",slug:"glaciers-and-the-polar-environment",bookSignature:"Masaki Kanao, Danilo Godone and Niccolò Dematteis",coverURL:"https://cdn.intechopen.com/books/images_new/9644.jpg",editors:[{id:"51959",title:"Dr.",name:"Masaki",middleName:null,surname:"Kanao",slug:"masaki-kanao",fullName:"Masaki Kanao"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"8985",title:"Natural Resources Management and Biological Sciences",subtitle:null,isOpenForSubmission:!1,hash:"5c2e219a6c021a40b5a20c041dea88c4",slug:"natural-resources-management-and-biological-sciences",bookSignature:"Edward R. Rhodes and Humood Naser",coverURL:"https://cdn.intechopen.com/books/images_new/8985.jpg",editors:[{id:"280886",title:"Prof.",name:"Edward R",middleName:null,surname:"Rhodes",slug:"edward-r-rhodes",fullName:"Edward R Rhodes"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9671",title:"Macrophages",subtitle:null,isOpenForSubmission:!1,hash:"03b00fdc5f24b71d1ecdfd75076bfde6",slug:"macrophages",bookSignature:"Hridayesh Prakash",coverURL:"https://cdn.intechopen.com/books/images_new/9671.jpg",editors:[{id:"287184",title:"Dr.",name:"Hridayesh",middleName:null,surname:"Prakash",slug:"hridayesh-prakash",fullName:"Hridayesh Prakash"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9313",title:"Clay Science and Technology",subtitle:null,isOpenForSubmission:!1,hash:"6fa7e70396ff10620e032bb6cfa6fb72",slug:"clay-science-and-technology",bookSignature:"Gustavo Morari Do Nascimento",coverURL:"https://cdn.intechopen.com/books/images_new/9313.jpg",editors:[{id:"7153",title:"Prof.",name:"Gustavo",middleName:null,surname:"Morari Do Nascimento",slug:"gustavo-morari-do-nascimento",fullName:"Gustavo Morari Do Nascimento"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9888",title:"Nuclear Power Plants",subtitle:"The Processes from the Cradle to the Grave",isOpenForSubmission:!1,hash:"c2c8773e586f62155ab8221ebb72a849",slug:"nuclear-power-plants-the-processes-from-the-cradle-to-the-grave",bookSignature:"Nasser Awwad",coverURL:"https://cdn.intechopen.com/books/images_new/9888.jpg",editors:[{id:"145209",title:"Prof.",name:"Nasser",middleName:"S",surname:"Awwad",slug:"nasser-awwad",fullName:"Nasser Awwad"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9027",title:"Human Blood Group Systems and Haemoglobinopathies",subtitle:null,isOpenForSubmission:!1,hash:"d00d8e40b11cfb2547d1122866531c7e",slug:"human-blood-group-systems-and-haemoglobinopathies",bookSignature:"Osaro Erhabor and Anjana Munshi",coverURL:"https://cdn.intechopen.com/books/images_new/9027.jpg",editors:[{id:"35140",title:null,name:"Osaro",middleName:null,surname:"Erhabor",slug:"osaro-erhabor",fullName:"Osaro Erhabor"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"7841",title:"New Insights Into Metabolic Syndrome",subtitle:null,isOpenForSubmission:!1,hash:"ef5accfac9772b9e2c9eff884f085510",slug:"new-insights-into-metabolic-syndrome",bookSignature:"Akikazu Takada",coverURL:"https://cdn.intechopen.com/books/images_new/7841.jpg",editors:[{id:"248459",title:"Dr.",name:"Akikazu",middleName:null,surname:"Takada",slug:"akikazu-takada",fullName:"Akikazu Takada"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"8558",title:"Aerodynamics",subtitle:null,isOpenForSubmission:!1,hash:"db7263fc198dfb539073ba0260a7f1aa",slug:"aerodynamics",bookSignature:"Mofid Gorji-Bandpy and Aly-Mousaad Aly",coverURL:"https://cdn.intechopen.com/books/images_new/8558.jpg",editors:[{id:"35542",title:"Prof.",name:"Mofid",middleName:null,surname:"Gorji-Bandpy",slug:"mofid-gorji-bandpy",fullName:"Mofid Gorji-Bandpy"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"7847",title:"Medical Toxicology",subtitle:null,isOpenForSubmission:!1,hash:"db9b65bea093de17a0855a1b27046247",slug:"medical-toxicology",bookSignature:"Pınar Erkekoglu and Tomohisa Ogawa",coverURL:"https://cdn.intechopen.com/books/images_new/7847.jpg",editors:[{id:"109978",title:"Prof.",name:"Pınar",middleName:null,surname:"Erkekoglu",slug:"pinar-erkekoglu",fullName:"Pınar Erkekoglu"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"10432",title:"Casting Processes and Modelling of Metallic Materials",subtitle:null,isOpenForSubmission:!1,hash:"2c5c9df938666bf5d1797727db203a6d",slug:"casting-processes-and-modelling-of-metallic-materials",bookSignature:"Zakaria Abdallah and Nada Aldoumani",coverURL:"https://cdn.intechopen.com/books/images_new/10432.jpg",editors:[{id:"201670",title:"Dr.",name:"Zak",middleName:null,surname:"Abdallah",slug:"zak-abdallah",fullName:"Zak Abdallah"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}}],offset:12,limit:12,total:5240},hotBookTopics:{hotBooks:[],offset:0,limit:12,total:null},publish:{},publishingProposal:{success:null,errors:{}},books:{featuredBooks:[{type:"book",id:"10065",title:"Wavelet Theory",subtitle:null,isOpenForSubmission:!1,hash:"d8868e332169597ba2182d9b004d60de",slug:"wavelet-theory",bookSignature:"Somayeh Mohammady",coverURL:"https://cdn.intechopen.com/books/images_new/10065.jpg",editors:[{id:"109280",title:"Dr.",name:"Somayeh",middleName:null,surname:"Mohammady",slug:"somayeh-mohammady",fullName:"Somayeh Mohammady"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9644",title:"Glaciers and the Polar Environment",subtitle:null,isOpenForSubmission:!1,hash:"e8cfdc161794e3753ced54e6ff30873b",slug:"glaciers-and-the-polar-environment",bookSignature:"Masaki Kanao, Danilo Godone and Niccolò Dematteis",coverURL:"https://cdn.intechopen.com/books/images_new/9644.jpg",editors:[{id:"51959",title:"Dr.",name:"Masaki",middleName:null,surname:"Kanao",slug:"masaki-kanao",fullName:"Masaki Kanao"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9385",title:"Renewable Energy",subtitle:"Technologies and Applications",isOpenForSubmission:!1,hash:"a6b446d19166f17f313008e6c056f3d8",slug:"renewable-energy-technologies-and-applications",bookSignature:"Tolga Taner, Archana Tiwari and Taha Selim Ustun",coverURL:"https://cdn.intechopen.com/books/images_new/9385.jpg",editors:[{id:"197240",title:"Associate Prof.",name:"Tolga",middleName:null,surname:"Taner",slug:"tolga-taner",fullName:"Tolga Taner"}],equalEditorOne:{id:"186791",title:"Dr.",name:"Archana",middleName:null,surname:"Tiwari",slug:"archana-tiwari",fullName:"Archana Tiwari",profilePictureURL:"https://mts.intechopen.com/storage/users/186791/images/system/186791.jpg",biography:"Dr. Archana Tiwari is Associate Professor at Amity University, India. Her research interests include renewable sources of energy from microalgae and further utilizing the residual biomass for the generation of value-added products, bioremediation through microalgae and microbial consortium, antioxidative enzymes and stress, and nutraceuticals from microalgae. She has been working on algal biotechnology for the last two decades. She has published her research in many international journals and has authored many books and chapters with renowned publishing houses. She has also delivered talks as an invited speaker at many national and international conferences. Dr. Tiwari is the recipient of several awards including Researcher of the Year and Distinguished Scientist.",institutionString:"Amity University",position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"3",totalChapterViews:"0",totalEditedBooks:"1",institution:{name:"Amity University",institutionURL:null,country:{name:"India"}}},equalEditorTwo:{id:"197609",title:"Prof.",name:"Taha Selim",middleName:null,surname:"Ustun",slug:"taha-selim-ustun",fullName:"Taha Selim Ustun",profilePictureURL:"https://mts.intechopen.com/storage/users/197609/images/system/197609.jpeg",biography:"Dr. Taha Selim Ustun received a Ph.D. in Electrical Engineering from Victoria University, Melbourne, Australia. He is a researcher with the Fukushima Renewable Energy Institute, AIST (FREA), where he leads the Smart Grid Cybersecurity Laboratory. Prior to that, he was a faculty member with the School of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA, USA. His current research interests include power systems protection, communication in power networks, distributed generation, microgrids, electric vehicle integration, and cybersecurity in smart grids. He serves on the editorial boards of IEEE Access, IEEE Transactions on Industrial Informatics, Energies, Electronics, Electricity, World Electric Vehicle and Information journals. Dr. Ustun is a member of the IEEE 2004 and 2800, IEC Renewable Energy Management WG 8, and IEC TC 57 WG17. He has been invited to run specialist courses in Africa, India, and China. He has delivered talks for the Qatar Foundation, the World Energy Council, the Waterloo Global Science Initiative, and the European Union Energy Initiative (EUEI). His research has attracted funding from prestigious programs in Japan, Australia, the European Union, and North America.",institutionString:"Fukushima Renewable Energy Institute, AIST (FREA)",position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"1",totalChapterViews:"0",totalEditedBooks:"0",institution:{name:"National Institute of Advanced Industrial Science and Technology",institutionURL:null,country:{name:"Japan"}}},equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"8985",title:"Natural Resources Management and Biological Sciences",subtitle:null,isOpenForSubmission:!1,hash:"5c2e219a6c021a40b5a20c041dea88c4",slug:"natural-resources-management-and-biological-sciences",bookSignature:"Edward R. Rhodes and Humood Naser",coverURL:"https://cdn.intechopen.com/books/images_new/8985.jpg",editors:[{id:"280886",title:"Prof.",name:"Edward R",middleName:null,surname:"Rhodes",slug:"edward-r-rhodes",fullName:"Edward R Rhodes"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9671",title:"Macrophages",subtitle:null,isOpenForSubmission:!1,hash:"03b00fdc5f24b71d1ecdfd75076bfde6",slug:"macrophages",bookSignature:"Hridayesh Prakash",coverURL:"https://cdn.intechopen.com/books/images_new/9671.jpg",editors:[{id:"287184",title:"Dr.",name:"Hridayesh",middleName:null,surname:"Prakash",slug:"hridayesh-prakash",fullName:"Hridayesh Prakash"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9313",title:"Clay Science and Technology",subtitle:null,isOpenForSubmission:!1,hash:"6fa7e70396ff10620e032bb6cfa6fb72",slug:"clay-science-and-technology",bookSignature:"Gustavo Morari Do Nascimento",coverURL:"https://cdn.intechopen.com/books/images_new/9313.jpg",editors:[{id:"7153",title:"Prof.",name:"Gustavo",middleName:null,surname:"Morari Do Nascimento",slug:"gustavo-morari-do-nascimento",fullName:"Gustavo Morari Do Nascimento"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9888",title:"Nuclear Power Plants",subtitle:"The Processes from the Cradle to the Grave",isOpenForSubmission:!1,hash:"c2c8773e586f62155ab8221ebb72a849",slug:"nuclear-power-plants-the-processes-from-the-cradle-to-the-grave",bookSignature:"Nasser Awwad",coverURL:"https://cdn.intechopen.com/books/images_new/9888.jpg",editors:[{id:"145209",title:"Prof.",name:"Nasser",middleName:"S",surname:"Awwad",slug:"nasser-awwad",fullName:"Nasser Awwad"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9027",title:"Human Blood Group Systems and Haemoglobinopathies",subtitle:null,isOpenForSubmission:!1,hash:"d00d8e40b11cfb2547d1122866531c7e",slug:"human-blood-group-systems-and-haemoglobinopathies",bookSignature:"Osaro Erhabor and Anjana Munshi",coverURL:"https://cdn.intechopen.com/books/images_new/9027.jpg",editors:[{id:"35140",title:null,name:"Osaro",middleName:null,surname:"Erhabor",slug:"osaro-erhabor",fullName:"Osaro Erhabor"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"10432",title:"Casting Processes and Modelling of Metallic Materials",subtitle:null,isOpenForSubmission:!1,hash:"2c5c9df938666bf5d1797727db203a6d",slug:"casting-processes-and-modelling-of-metallic-materials",bookSignature:"Zakaria Abdallah and Nada Aldoumani",coverURL:"https://cdn.intechopen.com/books/images_new/10432.jpg",editors:[{id:"201670",title:"Dr.",name:"Zak",middleName:null,surname:"Abdallah",slug:"zak-abdallah",fullName:"Zak Abdallah"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"7841",title:"New Insights Into Metabolic Syndrome",subtitle:null,isOpenForSubmission:!1,hash:"ef5accfac9772b9e2c9eff884f085510",slug:"new-insights-into-metabolic-syndrome",bookSignature:"Akikazu Takada",coverURL:"https://cdn.intechopen.com/books/images_new/7841.jpg",editors:[{id:"248459",title:"Dr.",name:"Akikazu",middleName:null,surname:"Takada",slug:"akikazu-takada",fullName:"Akikazu Takada"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}}],latestBooks:[{type:"book",id:"9243",title:"Coastal Environments",subtitle:null,isOpenForSubmission:!1,hash:"8e05e5f631e935eef366980f2e28295d",slug:"coastal-environments",bookSignature:"Yuanzhi Zhang and X. San Liang",coverURL:"https://cdn.intechopen.com/books/images_new/9243.jpg",editedByType:"Edited by",editors:[{id:"77597",title:"Prof.",name:"Yuanzhi",middleName:null,surname:"Zhang",slug:"yuanzhi-zhang",fullName:"Yuanzhi Zhang"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"10020",title:"Operations Management",subtitle:"Emerging Trend in the Digital Era",isOpenForSubmission:!1,hash:"526f0dbdc7e4d85b82ce8383ab894b4c",slug:"operations-management-emerging-trend-in-the-digital-era",bookSignature:"Antonella Petrillo, Fabio De Felice, Germano Lambert-Torres and Erik Bonaldi",coverURL:"https://cdn.intechopen.com/books/images_new/10020.jpg",editedByType:"Edited by",editors:[{id:"181603",title:"Dr.",name:"Antonella",middleName:null,surname:"Petrillo",slug:"antonella-petrillo",fullName:"Antonella Petrillo"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9521",title:"Antimicrobial Resistance",subtitle:"A One Health Perspective",isOpenForSubmission:!1,hash:"30949e78832e1afba5606634b52056ab",slug:"antimicrobial-resistance-a-one-health-perspective",bookSignature:"Mihai Mareș, Swee Hua Erin Lim, Kok-Song Lai and Romeo-Teodor Cristina",coverURL:"https://cdn.intechopen.com/books/images_new/9521.jpg",editedByType:"Edited by",editors:[{id:"88785",title:"Prof.",name:"Mihai",middleName:null,surname:"Mares",slug:"mihai-mares",fullName:"Mihai Mares"}],equalEditorOne:{id:"190224",title:"Dr.",name:"Swee Hua Erin",middleName:null,surname:"Lim",slug:"swee-hua-erin-lim",fullName:"Swee Hua Erin Lim",profilePictureURL:"https://mts.intechopen.com/storage/users/190224/images/system/190224.png",biography:"Dr. Erin Lim is presently working as an Assistant Professor in the Division of Health Sciences, Abu Dhabi Women\\'s College, Higher Colleges of Technology in Abu Dhabi, United Arab Emirates and is affiliated as an Associate Professor to Perdana University-Royal College of Surgeons in Ireland, Selangor, Malaysia. She obtained her Ph.D. from Universiti Putra Malaysia in 2010 with a National Science Fellowship awarded from the Ministry of Science, Technology and Innovation Malaysia and has been actively involved in research ever since. Her main research interests include analysis of carriage and transmission of multidrug resistant bacteria in non-conventional settings, besides an interest in natural products for antimicrobial testing. She is heavily involved in the elucidation of mechanisms of reversal of resistance in bacteria in addition to investigating the immunological analyses of diseases, development of vaccination and treatment models in animals. She hopes her work will support the discovery of therapeutics in the clinical setting and assist in the combat against the burden of antibiotic resistance.",institutionString:"Abu Dhabi Women’s College",position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"3",totalChapterViews:"0",totalEditedBooks:"0",institution:{name:"Perdana University",institutionURL:null,country:{name:"Malaysia"}}},equalEditorTwo:{id:"221544",title:"Dr.",name:"Kok-Song",middleName:null,surname:"Lai",slug:"kok-song-lai",fullName:"Kok-Song Lai",profilePictureURL:"https://mts.intechopen.com/storage/users/221544/images/system/221544.jpeg",biography:"Dr. Lai Kok Song is an Assistant Professor in the Division of Health Sciences, Abu Dhabi Women\\'s College, Higher Colleges of Technology in Abu Dhabi, United Arab Emirates. He obtained his Ph.D. in Biological Sciences from Nara Institute of Science and Technology, Japan in 2012. Prior to his academic appointment, Dr. Lai worked as a Senior Scientist at the Ministry of Science, Technology and Innovation, Malaysia. His current research areas include antimicrobial resistance and plant-pathogen interaction. His particular interest lies in the study of the antimicrobial mechanism via membrane disruption of essential oils against multi-drug resistance bacteria through various biochemical, molecular and proteomic approaches. Ultimately, he hopes to uncover and determine novel biomarkers related to antibiotic resistance that can be developed into new therapeutic strategies.",institutionString:"Higher Colleges of Technology",position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"8",totalChapterViews:"0",totalEditedBooks:"0",institution:{name:"Higher Colleges of Technology",institutionURL:null,country:{name:"United Arab Emirates"}}},equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9560",title:"Creativity",subtitle:"A Force to Innovation",isOpenForSubmission:!1,hash:"58f740bc17807d5d88d647c525857b11",slug:"creativity-a-force-to-innovation",bookSignature:"Pooja Jain",coverURL:"https://cdn.intechopen.com/books/images_new/9560.jpg",editedByType:"Edited by",editors:[{id:"316765",title:"Dr.",name:"Pooja",middleName:null,surname:"Jain",slug:"pooja-jain",fullName:"Pooja Jain"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9669",title:"Recent Advances in Rice Research",subtitle:null,isOpenForSubmission:!1,hash:"12b06cc73e89af1e104399321cc16a75",slug:"recent-advances-in-rice-research",bookSignature:"Mahmood-ur- Rahman Ansari",coverURL:"https://cdn.intechopen.com/books/images_new/9669.jpg",editedByType:"Edited by",editors:[{id:"185476",title:"Dr.",name:"Mahmood-Ur-",middleName:null,surname:"Rahman Ansari",slug:"mahmood-ur-rahman-ansari",fullName:"Mahmood-Ur- Rahman Ansari"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"10192",title:"Background and Management of Muscular Atrophy",subtitle:null,isOpenForSubmission:!1,hash:"eca24028d89912b5efea56e179dff089",slug:"background-and-management-of-muscular-atrophy",bookSignature:"Julianna Cseri",coverURL:"https://cdn.intechopen.com/books/images_new/10192.jpg",editedByType:"Edited by",editors:[{id:"135579",title:"Dr.",name:"Julianna",middleName:null,surname:"Cseri",slug:"julianna-cseri",fullName:"Julianna Cseri"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9550",title:"Entrepreneurship",subtitle:"Contemporary Issues",isOpenForSubmission:!1,hash:"9b4ac1ee5b743abf6f88495452b1e5e7",slug:"entrepreneurship-contemporary-issues",bookSignature:"Mladen Turuk",coverURL:"https://cdn.intechopen.com/books/images_new/9550.jpg",editedByType:"Edited by",editors:[{id:"319755",title:"Prof.",name:"Mladen",middleName:null,surname:"Turuk",slug:"mladen-turuk",fullName:"Mladen Turuk"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"10065",title:"Wavelet Theory",subtitle:null,isOpenForSubmission:!1,hash:"d8868e332169597ba2182d9b004d60de",slug:"wavelet-theory",bookSignature:"Somayeh Mohammady",coverURL:"https://cdn.intechopen.com/books/images_new/10065.jpg",editedByType:"Edited by",editors:[{id:"109280",title:"Dr.",name:"Somayeh",middleName:null,surname:"Mohammady",slug:"somayeh-mohammady",fullName:"Somayeh Mohammady"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9313",title:"Clay Science and Technology",subtitle:null,isOpenForSubmission:!1,hash:"6fa7e70396ff10620e032bb6cfa6fb72",slug:"clay-science-and-technology",bookSignature:"Gustavo Morari Do Nascimento",coverURL:"https://cdn.intechopen.com/books/images_new/9313.jpg",editedByType:"Edited by",editors:[{id:"7153",title:"Prof.",name:"Gustavo",middleName:null,surname:"Morari Do Nascimento",slug:"gustavo-morari-do-nascimento",fullName:"Gustavo Morari Do Nascimento"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9888",title:"Nuclear Power Plants",subtitle:"The Processes from the Cradle to the Grave",isOpenForSubmission:!1,hash:"c2c8773e586f62155ab8221ebb72a849",slug:"nuclear-power-plants-the-processes-from-the-cradle-to-the-grave",bookSignature:"Nasser Awwad",coverURL:"https://cdn.intechopen.com/books/images_new/9888.jpg",editedByType:"Edited by",editors:[{id:"145209",title:"Prof.",name:"Nasser",middleName:"S",surname:"Awwad",slug:"nasser-awwad",fullName:"Nasser Awwad"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}}]},subject:{topic:{id:"845",title:"Ecosystem",slug:"environmental-sciences-ecology-ecosystem",parent:{title:"Ecology",slug:"environmental-sciences-ecology"},numberOfBooks:5,numberOfAuthorsAndEditors:140,numberOfWosCitations:85,numberOfCrossrefCitations:44,numberOfDimensionsCitations:122,videoUrl:null,fallbackUrl:null,description:null},booksByTopicFilter:{topicSlug:"environmental-sciences-ecology-ecosystem",sort:"-publishedDate",limit:12,offset:0},booksByTopicCollection:[{type:"book",id:"8978",title:"Changing Ecosystems and Their Services",subtitle:null,isOpenForSubmission:!1,hash:"825fa534e3cff809ca6d965327fe2d67",slug:"changing-ecosystems-and-their-services",bookSignature:"Levente Hufnagel",coverURL:"https://cdn.intechopen.com/books/images_new/8978.jpg",editedByType:"Edited by",editors:[{id:"10864",title:"Dr.",name:"Levente",middleName:null,surname:"Hufnagel",slug:"levente-hufnagel",fullName:"Levente Hufnagel"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"7535",title:"Wetlands Management",subtitle:"Assessing Risk and Sustainable Solutions",isOpenForSubmission:!1,hash:"4bb1768b7d5af4fc017028ed386b550b",slug:"wetlands-management-assessing-risk-and-sustainable-solutions",bookSignature:"Didem Gökçe",coverURL:"https://cdn.intechopen.com/books/images_new/7535.jpg",editedByType:"Edited by",editors:[{id:"178260",title:"Associate Prof.",name:"Didem",middleName:null,surname:"Gokce",slug:"didem-gokce",fullName:"Didem Gokce"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"6570",title:"Ecosystem Services and Global Ecology",subtitle:null,isOpenForSubmission:!1,hash:"659109f1d6de7b7f6dce3cfa5011d7b3",slug:"ecosystem-services-and-global-ecology",bookSignature:"Levente Hufnagel",coverURL:"https://cdn.intechopen.com/books/images_new/6570.jpg",editedByType:"Edited by",editors:[{id:"10864",title:"Dr.",name:"Levente",middleName:null,surname:"Hufnagel",slug:"levente-hufnagel",fullName:"Levente Hufnagel"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"6099",title:"Symbiosis",subtitle:null,isOpenForSubmission:!1,hash:"309fee35292674da9b56e03269ca4291",slug:"symbiosis",bookSignature:"Everlon Cid Rigobelo",coverURL:"https://cdn.intechopen.com/books/images_new/6099.jpg",editedByType:"Edited by",editors:[{id:"39553",title:"Prof.",name:"Everlon",middleName:"Cid",surname:"Rigobelo",slug:"everlon-rigobelo",fullName:"Everlon Rigobelo"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"1367",title:"Research in Biodiversity",subtitle:"Models and Applications",isOpenForSubmission:!1,hash:"213516a0e507a15f628317e141e39506",slug:"research-in-biodiversity-models-and-applications",bookSignature:"Igor Ya. Pavlinov",coverURL:"https://cdn.intechopen.com/books/images_new/1367.jpg",editedByType:"Edited by",editors:[{id:"50006",title:"Dr.",name:"Igor",middleName:null,surname:"Pavlinov",slug:"igor-pavlinov",fullName:"Igor Pavlinov"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}}],booksByTopicTotal:5,mostCitedChapters:[{id:"61029",doi:"10.5772/intechopen.75705",title:"Laticifers and Secretory Ducts: Similarities and Differences",slug:"laticifers-and-secretory-ducts-similarities-and-differences",totalDownloads:761,totalCrossrefCites:8,totalDimensionsCites:19,book:{slug:"ecosystem-services-and-global-ecology",title:"Ecosystem Services and Global Ecology",fullTitle:"Ecosystem Services and Global Ecology"},signatures:"Erika Prado and Diego Demarco",authors:[{id:"237096",title:"Ph.D.",name:"Diego",middleName:null,surname:"Demarco",slug:"diego-demarco",fullName:"Diego Demarco"},{id:"237322",title:"Ms.",name:"Erika",middleName:null,surname:"Prado",slug:"erika-prado",fullName:"Erika Prado"}]},{id:"59280",doi:"10.5772/intechopen.73495",title:"Potential of Rhizobia in Improving Nitrogen Fixation and Yields of Legumes",slug:"potential-of-rhizobia-in-improving-nitrogen-fixation-and-yields-of-legumes",totalDownloads:1412,totalCrossrefCites:7,totalDimensionsCites:13,book:{slug:"symbiosis",title:"Symbiosis",fullTitle:"Symbiosis"},signatures:"Yassine Mabrouk, Imen Hemissi, Issam Ben Salem, Sonia Mejri,\nMouldi Saidi and Omrane Belhadj",authors:[{id:"114694",title:"Prof.",name:"Omrane",middleName:null,surname:"Belhadj",slug:"omrane-belhadj",fullName:"Omrane Belhadj"},{id:"169165",title:"Dr.",name:"Mabrouk",middleName:null,surname:"Yassine",slug:"mabrouk-yassine",fullName:"Mabrouk Yassine"},{id:"193503",title:"Dr.",name:"Issam",middleName:null,surname:"Ben Salem",slug:"issam-ben-salem",fullName:"Issam Ben Salem"},{id:"203025",title:"Dr.",name:"Imen",middleName:null,surname:"Hemissi",slug:"imen-hemissi",fullName:"Imen Hemissi"},{id:"203027",title:"Prof.",name:"Mouldi",middleName:null,surname:"Saidi",slug:"mouldi-saidi",fullName:"Mouldi Saidi"},{id:"219610",title:"Dr.",name:"Sonia",middleName:null,surname:"Mejri",slug:"sonia-mejri",fullName:"Sonia Mejri"}]},{id:"21530",doi:"10.5772/24906",title:"Towards a Better Understanding of Beta Diversity: Deconstructing Composition Patterns of Saproxylic Beetles Breeding in Recently Burnt Boreal Forest",slug:"towards-a-better-understanding-of-beta-diversity-deconstructing-composition-patterns-of-saproxylic-b",totalDownloads:4009,totalCrossrefCites:0,totalDimensionsCites:11,book:{slug:"research-in-biodiversity-models-and-applications",title:"Research in Biodiversity",fullTitle:"Research in Biodiversity - Models and Applications"},signatures:"Ermias T. Azeria, Jacques Ibarzabal, Jonathan Boucher and Christian Hébert",authors:[{id:"60303",title:"Dr.",name:"Ermias",middleName:"T.",surname:"Azeria",slug:"ermias-azeria",fullName:"Ermias Azeria"},{id:"61735",title:"Dr.",name:"Jacques",middleName:null,surname:"Ibarzabal",slug:"jacques-ibarzabal",fullName:"Jacques Ibarzabal"},{id:"61736",title:"MSc",name:"Jonathan",middleName:null,surname:"Boucher",slug:"jonathan-boucher",fullName:"Jonathan Boucher"},{id:"61737",title:"Dr.",name:"Christian",middleName:null,surname:"Hébert",slug:"christian-hebert",fullName:"Christian Hébert"}]}],mostDownloadedChaptersLast30Days:[{id:"67892",title:"An Economic Valuation and Mapping of Pollination Services in Ethiopia",slug:"an-economic-valuation-and-mapping-of-pollination-services-in-ethiopia",totalDownloads:296,totalCrossrefCites:0,totalDimensionsCites:0,book:{slug:"changing-ecosystems-and-their-services",title:"Changing Ecosystems and Their Services",fullTitle:"Changing Ecosystems and Their Services"},signatures:"Dawit Woubishet Mulatu",authors:[{id:"305838",title:"Dr.",name:"Dawit",middleName:null,surname:"Mulatu",slug:"dawit-mulatu",fullName:"Dawit Mulatu"}]},{id:"64675",title:"Introductory Chapter: Wetland Importance and Management",slug:"introductory-chapter-wetland-importance-and-management",totalDownloads:1464,totalCrossrefCites:4,totalDimensionsCites:4,book:{slug:"wetlands-management-assessing-risk-and-sustainable-solutions",title:"Wetlands Management",fullTitle:"Wetlands Management - Assessing Risk and Sustainable Solutions"},signatures:"Didem Gokce",authors:[{id:"178260",title:"Associate Prof.",name:"Didem",middleName:null,surname:"Gokce",slug:"didem-gokce",fullName:"Didem Gokce"}]},{id:"59049",title:"Ecosystem Services Provided by Benthic Macroinvertebrate Assemblages in Marine Coastal Zones",slug:"ecosystem-services-provided-by-benthic-macroinvertebrate-assemblages-in-marine-coastal-zones",totalDownloads:703,totalCrossrefCites:0,totalDimensionsCites:0,book:{slug:"ecosystem-services-and-global-ecology",title:"Ecosystem Services and Global Ecology",fullTitle:"Ecosystem Services and Global Ecology"},signatures:"Gwynne Stoner Rife",authors:[{id:"225447",title:"Dr.",name:"Gwynne",middleName:null,surname:"Rife",slug:"gwynne-rife",fullName:"Gwynne Rife"}]},{id:"21531",title:"Twenty Landmark Papers in Biodiversity Conservation",slug:"twenty-landmark-papers-in-biodiversity-conservation",totalDownloads:6644,totalCrossrefCites:0,totalDimensionsCites:3,book:{slug:"research-in-biodiversity-models-and-applications",title:"Research in Biodiversity",fullTitle:"Research in Biodiversity - Models and Applications"},signatures:"Corey J. A. Bradshaw, Navjot S. Sodhi, William F. Laurance and Barry W. Brook",authors:[{id:"54768",title:"Prof.",name:"Corey",middleName:"James Alexander",surname:"Bradshaw",slug:"corey-bradshaw",fullName:"Corey Bradshaw"},{id:"54773",title:"Prof.",name:"Navjot",middleName:null,surname:"Sodhi",slug:"navjot-sodhi",fullName:"Navjot Sodhi"},{id:"54774",title:"Prof.",name:"William",middleName:null,surname:"Laurance",slug:"william-laurance",fullName:"William Laurance"},{id:"54775",title:"Prof.",name:"Barry",middleName:null,surname:"Brook",slug:"barry-brook",fullName:"Barry Brook"}]},{id:"21526",title:"Towards Bridging Worldviews in Biodiversity Conservation: Exploring the Tsonga Concept of Ntumbuloko in South Africa",slug:"towards-bridging-worldviews-in-biodiversity-conservation-exploring-the-tsonga-concept-of-ntumbuloko-",totalDownloads:2788,totalCrossrefCites:0,totalDimensionsCites:1,book:{slug:"research-in-biodiversity-models-and-applications",title:"Research in Biodiversity",fullTitle:"Research in Biodiversity - Models and Applications"},signatures:"Brandon P. Anthony, Sylvia Abonyi, Petra Terblanche and Alan Watt",authors:[{id:"50324",title:"Dr.",name:"Brandon",middleName:null,surname:"Anthony",slug:"brandon-anthony",fullName:"Brandon Anthony"},{id:"85901",title:"Prof.",name:"Alan",middleName:null,surname:"Watt",slug:"alan-watt",fullName:"Alan Watt"},{id:"85902",title:"Mrs.",name:"Petra",middleName:null,surname:"Terblanche",slug:"petra-terblanche",fullName:"Petra Terblanche"},{id:"85903",title:"Prof.",name:"Sylvia",middleName:null,surname:"Abonyi",slug:"sylvia-abonyi",fullName:"Sylvia Abonyi"}]},{id:"21538",title:"Biodiversity Conservation Planning in Rural Landscapes in Japan: Integration of Ecological and Visual Perspectives",slug:"biodiversity-conservation-planning-in-rural-landscapes-in-japan-integration-of-ecological-and-visual",totalDownloads:2294,totalCrossrefCites:3,totalDimensionsCites:3,book:{slug:"research-in-biodiversity-models-and-applications",title:"Research in Biodiversity",fullTitle:"Research in Biodiversity - Models and Applications"},signatures:"Yoji Natori, Janet Silbernagel and Michael S. Adams",authors:[{id:"52950",title:"Dr.",name:"Yoji",middleName:null,surname:"Natori",slug:"yoji-natori",fullName:"Yoji Natori"},{id:"61498",title:"Dr.",name:"Janet",middleName:null,surname:"Silbernagel",slug:"janet-silbernagel",fullName:"Janet Silbernagel"},{id:"61499",title:"Dr.",name:"Michael",middleName:null,surname:"Adams",slug:"michael-adams",fullName:"Michael Adams"}]},{id:"59798",title:"Non-Native Invasive Species as Ecosystem Service Providers",slug:"non-native-invasive-species-as-ecosystem-service-providers",totalDownloads:1005,totalCrossrefCites:0,totalDimensionsCites:4,book:{slug:"ecosystem-services-and-global-ecology",title:"Ecosystem Services and Global Ecology",fullTitle:"Ecosystem Services and Global Ecology"},signatures:"Barbara Sladonja, Danijela Poljuha and Mirela Uzelac",authors:[{id:"88464",title:"Dr.",name:"Barbara",middleName:null,surname:"Sladonja",slug:"barbara-sladonja",fullName:"Barbara Sladonja"},{id:"227713",title:"Dr.",name:"Danijela",middleName:null,surname:"Poljuha",slug:"danijela-poljuha",fullName:"Danijela Poljuha"},{id:"243906",title:"MSc.",name:"Mirela",middleName:null,surname:"Uzelac",slug:"mirela-uzelac",fullName:"Mirela Uzelac"}]},{id:"21530",title:"Towards a Better Understanding of Beta Diversity: Deconstructing Composition Patterns of Saproxylic Beetles Breeding in Recently Burnt Boreal Forest",slug:"towards-a-better-understanding-of-beta-diversity-deconstructing-composition-patterns-of-saproxylic-b",totalDownloads:4007,totalCrossrefCites:0,totalDimensionsCites:11,book:{slug:"research-in-biodiversity-models-and-applications",title:"Research in Biodiversity",fullTitle:"Research in Biodiversity - Models and Applications"},signatures:"Ermias T. Azeria, Jacques Ibarzabal, Jonathan Boucher and Christian Hébert",authors:[{id:"60303",title:"Dr.",name:"Ermias",middleName:"T.",surname:"Azeria",slug:"ermias-azeria",fullName:"Ermias Azeria"},{id:"61735",title:"Dr.",name:"Jacques",middleName:null,surname:"Ibarzabal",slug:"jacques-ibarzabal",fullName:"Jacques Ibarzabal"},{id:"61736",title:"MSc",name:"Jonathan",middleName:null,surname:"Boucher",slug:"jonathan-boucher",fullName:"Jonathan Boucher"},{id:"61737",title:"Dr.",name:"Christian",middleName:null,surname:"Hébert",slug:"christian-hebert",fullName:"Christian Hébert"}]},{id:"59861",title:"Ecosystem Service Mapping: A Management-Oriented Approach to Support Environmental Planning Process",slug:"ecosystem-service-mapping-a-management-oriented-approach-to-support-environmental-planning-process",totalDownloads:967,totalCrossrefCites:0,totalDimensionsCites:1,book:{slug:"ecosystem-services-and-global-ecology",title:"Ecosystem Services and Global Ecology",fullTitle:"Ecosystem Services and Global Ecology"},signatures:"Lisa Pinto de Sousa, Ana I. Lillebø and Fátima L. Alves",authors:[{id:"220988",title:"Dr.",name:"Ana",middleName:null,surname:"Lillebø",slug:"ana-lillebo",fullName:"Ana Lillebø"},{id:"228742",title:"Ph.D.",name:"Lisa",middleName:null,surname:"Sousa",slug:"lisa-sousa",fullName:"Lisa Sousa"},{id:"228745",title:"Prof.",name:"Fátima",middleName:null,surname:"Alves",slug:"fatima-alves",fullName:"Fátima Alves"}]},{id:"62933",title:"Introductory Chapter: Evaluation Methods of Ecosystem Services and Their Scientific and Societal Importance in Service of Solving the Global Problems of the Humankind",slug:"introductory-chapter-evaluation-methods-of-ecosystem-services-and-their-scientific-and-societal-impo",totalDownloads:742,totalCrossrefCites:0,totalDimensionsCites:0,book:{slug:"ecosystem-services-and-global-ecology",title:"Ecosystem Services and Global Ecology",fullTitle:"Ecosystem Services and Global Ecology"},signatures:"Levente Hufnagel, Ferenc Mics and Réka Homoródi",authors:[{id:"10864",title:"Dr.",name:"Levente",middleName:null,surname:"Hufnagel",slug:"levente-hufnagel",fullName:"Levente Hufnagel"},{id:"268024",title:"MSc.",name:"Ferenc",middleName:null,surname:"Mics",slug:"ferenc-mics",fullName:"Ferenc Mics"},{id:"268025",title:"MSc.",name:"Réka",middleName:null,surname:"Homoródi",slug:"reka-homorodi",fullName:"Réka Homoródi"}]}],onlineFirstChaptersFilter:{topicSlug:"environmental-sciences-ecology-ecosystem",limit:3,offset:0},onlineFirstChaptersCollection:[],onlineFirstChaptersTotal:0},preDownload:{success:null,errors:{}},aboutIntechopen:{},privacyPolicy:{},peerReviewing:{},howOpenAccessPublishingWithIntechopenWorks:{},sponsorshipBooks:{sponsorshipBooks:[{type:"book",id:"10176",title:"Microgrids and Local Energy Systems",subtitle:null,isOpenForSubmission:!0,hash:"c32b4a5351a88f263074b0d0ca813a9c",slug:null,bookSignature:"Prof. Nick Jenkins",coverURL:"https://cdn.intechopen.com/books/images_new/10176.jpg",editedByType:null,editors:[{id:"55219",title:"Prof.",name:"Nick",middleName:null,surname:"Jenkins",slug:"nick-jenkins",fullName:"Nick Jenkins"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}}],offset:8,limit:8,total:1},route:{name:"profile.detail",path:"/profiles/86544/giorgio-berton",hash:"",query:{},params:{id:"86544",slug:"giorgio-berton"},fullPath:"/profiles/86544/giorgio-berton",meta:{},from:{name:null,path:"/",hash:"",query:{},params:{},fullPath:"/",meta:{}}}},function(){var e;(e=document.currentScript||document.scripts[document.scripts.length-1]).parentNode.removeChild(e)}()