bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring the electron density localization in single MoS2 monolayers by means of a localize-electrons detector and the quantum theory of atoms in molecules
Authors: Aray Yosslen
Published: November 2017

The nature of the electron density localization in a MoS2 monolayer under 0 % to 11% tensile strain has been systematically studied by means of a localized electron detector function and the Quantum Theory of atoms in molecules. At 10% tensile strain, this monolayer become metallic. It was found that for less than 6.5% of applied stress, the same atomic structure of the equilibrium geometry (0% strain) is maintained; while over 6.5% strain induces a transformation to a structure where the sulfur atoms placed on the top and bottom layer form S2 groups. The localized electron detector function shows the presence of zones of highly electron delocalization extending throughout the Mo central layer. For less than 10% tensile strain, these zones comprise the BCPs and the remainder CPs in separates regions of the space; while for the structures beyond 10% strain, all the critical points are involved in a region of highly delocalized electrons that extends throughout the material. This dissimilar electron localization pattern is like to that previously reported for semiconductors such as Ge bulk and metallic systems such as transition metals bulk.
Epitaxial growth of LiCoO2 thin films with (001) orientation
Authors: Okada Koichi , Ohnishi Tsuyoshi , Mitsuishi Kazutaka , Takada Kazunori
Published: November 2017

The layered structure of LiCoO2 implies anisotropic ionic conduction; however, experimental data have never demonstrated this. The anisotropy can be observed clearly in epitaxial films with controlled orientations. Our previous study had reported that LiCoO2 grows epitaxially on Nb-doped SrTiO3 (100) and (110) substrates with complete (104) and (018) orientations, respectively. On the other hand, the growth on SrTiO3 (111) substrates with (001) orientation was accompanied by the inclusion of (012)-oriented domains, although the (012) orientation is higher in the energy state than the (001). The present study reveals that lower laser energy density (fluence) and lower substrate temperature decrease the amount of inclusions; that is, the occurrence of the (012) orientation in spite of its higher energy is governed by these factors. Higher fluence leading to higher deposition rates does not provide sufficient time for the cations to be rearranged into the (001) orientation, and the higher substrate temperature increases the nucleation frequency for the (012) orientation. A micrograph of the final (001)-oriented film reveals that the LiCoO2 film grows in an island growth mode.
Heating of heavy plasma species by damping electron beam in beam-generated plasma
Authors: Levko Dmitry
Published: November 2017

The heating of heavy species (both ions and neutrals) in the beam-generated plasma by damping electron beam is analyzed using a self-consistent one-dimensional Particle-in-Cell Monte Carlo collisions model. It is observed that the damping of the electron beam leads to the excitation of a wide spectrum of electrostatic waves. These waves lead to the heating not only of the thermal plasma electrons but also of the plasma ions. The first less efficient mechanism of the ion heating is the ponderomotive force due to the generation of non-homogeneous high-frequency electric field which is excited by the damping electron beam. The second more efficient mechanism of the ion heating obtained in the simulations is the acceleration by slow plasma waves. This mechanism is responsible for the acceleration of ions to the velocities few times higher than the ion thermal velocity.
Highly stretchable metallic silver electrodes on poly(dimethylsiloxane) substrate
Authors: Jang Ikjun , Jeong Jaewook
Published: November 2017

In this study, Ag stretchable electrodes with a very high stretching capability, exceeding 59 %, were fabricated using a combination of prestretching and O2 plasma treatments on poly(dimethylsiloxane) substrates. The resistance increased by a factor of only 4.8 compared to the initial value when 59% strain was applied. The high performance of the O2-plasma-treated sample is attributed to the initial formation of large periodic wavy structures without cracks, which effectively release the external strain under the stretched condition. In addition, the sample showed a stable operation with no variation in the resistance under prolonged and cyclic strains of 20 % for 500 cycles. Owing to the simple fabrication process and high performance, it is expected that the Ag electrodes can be used for high-end applications such as interconnections of devices and circuits.
What’s in a name? An overview of organisational health literacy terminology
Authors: Meggetto Elizabeth , Ward Bernadette , Isaccs Anton
Published: November 2017

Organisational health literacy (OHL) is a relatively new concept and its role in improving population health outcomes is gaining recognition. There are several terms being used in relation to OHL but there is no consensus about the definition of OHL nor agreement on a single approach to its application within health services. This contested space continues to create discussion and debate between health literacy researchers worldwide. Increasingly, health service accreditation standards are moving towards including OHL and so services need to clearly define their roles and responsibilities in this area. Inherent in this is the need to develop and validate quantifiable measures of OHL change. This is not to say it needs a ‘one-size-fits-all’ approach but rather that terminology needs to be fit for purpose. This paper reviews the literature on OHL, describing and contrasting OHL terminology to assist practitioners seeking OHL information and health services clarifying their roles and responsibilities in this area. What is known about the topic? Organisational health literacy (OHL) is a new and emerging field. Currently there is no agreed definition or approach to OHL. As a result there is a large number of terms being used to describe OHL and this can make it difficult for practitioners and health services to understand the meanings of the different terms and how they can be used when seeking OHL information and its application to health service policy. What does this paper add? This paper provides an overview of 19 different OHL terms currently in use and how they apply in a range of health service contexts. What are the implications for practitioners? This paper provides practitioners with an overview of OHL terms currently in use and how they can be used to seek information and evidence to inform practice or develop health service OHL policy. This will allow health services to ensure they can clearly define their roles and responsibilities in OHL for accreditation purposes by ensuring that terminology use is fit for purpose. Lastly, the paper provides an inventory of terminology to be used when searching for evidence-based practices in OHL. This ensures all relevant papers can be captured, leading to robust and thorough reviews of the evidence most relevant to the OHL area of focus.
Strain-hardening characteristics of ferrite layers in pearlite microstructure
Authors: Yasuda Y. , Ohashi T. , Shimokawa T. , Niiyama T.
Published: November 2017

Strain hardening of ferrite layers in pearlite microstructures plays a crucial role in the stability of elasto-plastic deformation of pearlite. The effects of layer thickness, crystal orientation relationship and loading direction on the strain-hardening characteristics of the ferrite layers were studied by crystal plasticity analysis. The results show that the strain-hardening rate increases in the ferrite layers with small thickness, whereas at the same thickness, the strain-hardening rate varies depending on the loading direction and crystal orientation relationship. When the Schmid factors and mean-free paths of the activated systems are small and short, the strain-hardening rate tends to be high. The ferrite layer exhibits a remarkably high strain-hardening rate when slip systems are sequentially activated with the increase of deformation.

This is part of a thematic issue on Pearlitic Steel Wires.
Higher education regionalism in Europe and Southeast Asia: Comparing policy ideas
Authors: Chou Meng-Hsuan , Ravinet Pauline
Published: November 2017

Regional cooperation in the higher education policy sector has been on the rise throughout the last decades. In this article, we compare and analyse two instances of higher education regionalisms (i.e. political projects of higher education region creation) in Europe and South-East Asia from an ideational perspective. In so doing, we engage with and challenge the diffusion argument common in both European higher education studies (‘Bologna Process export thesis’) and new comparative regionalism. Using publicly accessible documents from regional bodies active in higher education policy coordination, and 53 semi-structured interviews with key policy actors involved in these developments, we identify the policy ideas of European and South-East Asian higher education regionalisms, and consider whether the extant models of regional cooperation and the knowledge discourse affected their evolution. Our findings indicate that the ‘Bologna Process export thesis’ and the diffusion assumptions of comparative regionalism are too simplistic and misleading. We conclude with suggestions for scholars interested in new comparative regionalism.
Policy learning and policy networks in theory and practice: the role of policy brokers in the Indonesian biodiesel policy network
Authors: Howlett Michael , Mukherjee Ishani , Koppenjan Joop
Published: November 2017

This paper examines how learning has been treated, generally, in policy network theories and what questions have been posed, and answered, about this phenomenon to date. We examine to what extent network characteristics and especially the presence of various types of brokers impede or facilitate policy learning. Next, a case study of the policy network surrounding the sustainability of palm oil biodiesel in Indonesia over the past two decades is presented using social network analysis. This case study focuses on sustainability-oriented policy learning in the Indonesian biodiesel governance network and illustrates how network features and especially forms of brokerage influence learning.
Learning in the bath-tub: the micro and macro dimensions of the causal relationship between learning and policy change
Authors: Dunlop Claire A , Radaelli Claudio M
Published: November 2017

Whilst the literature classifies policy learning in terms of types or ontological approaches (reflexive and social constructivist learning versus rational up-dating of priors), we offer a three-dimensional approach to explore the relationships between individual learning, learning in groups and the macro-dimension. Our contribution maps most (although not all) lively debates in the field on a multi-dimensional space and explores the logic of causality from micro to macro. To achieve these two aims, we draw on Coleman’s ‘bath-tub’. We map learning in the bath-tub by considering prominent studies on learning but also, in some cases, by exploring and drawing lessons from political science and behavioural sciences. By integrating findings in an eclectic way, we explain the logic of learning using a single template and suggest methods for empirical analysis. This is not a literature review but an original attempt to capture the causal architecture of the field, contributing to learning theory with findings from mainstream political and behavioural sciences.
Changing public service delivery: learning in co-creation
Authors: Voorberg William , Bekkers Victor , Timeus Krista , Tonurist Piret , Tummers Lars
Published: November 2017

Co-creation – where citizens and public organizations work together to deal with societal issues – is increasingly considered as a fertile solution for various public service delivery problems. During co-creation, citizens are not mere consumers, but are actively engaged in building resilient societies. In this study, we analyze if and how state and governance traditions influence learning and policy change within a context of co-creation. We combine insights from the co-creation and learning literature. The empirical strategy is a comparative case study of co-creation examples within the welfare domain in childcare (Estonia), education (Germany) and community work (the Netherlands). We show that state and governance traditions may form an explanation for whether co-creation, learning and policy change occurs. Our paper suggests that this seems to be related to whether there is a tradition of working together with citizens and a focus on rule following or not.
What is so wicked about wicked problems? A conceptual analysis and a research program
Authors: Peters B Guy
Published: November 2017

The concept of wicked problems has become a fad in contemporary policy analysis, with any number of problems being labeled as “wicked”. However, if many of these problems are analyzed using a strict definition of the concept they do not meet the criteria. Building on this analysis, I have developed a research program to investigate the extent to which even those problems usually thought to be wicked are actually that difficult.
Wicked problem definition and gradual institutional change: federalism and immigration in Canada and Australia
Authors: Paquet Mireille
Published: November 2017

This article examines the impacts of problem definition, defined as a social mechanism, in bringing about gradual institutional change. Focusing on a similar process of gradual institutional change in Canada and Australia, it shows that problem definition is one pathway by which actors’ interests and behaviors are redefined inside an institutional regime. By tracing the process of federalization of Canada and Australia’s immigration regime since the 1990, it demonstrates that problem definition contributed to the rise of subnational governments as legitimate actors in the management of immigration. In these two countries, the specificities of the operation of this mechanism, including the actors mobilized for change, and the content of the policy problem being put forward generated different processes of federalization that nonetheless resulted in inclusive immigration federalism. In dialogue with historical institutionalism, this points to the potential of the mechanismic approach for theory building regarding the consequences of the dynamics of problem definition.
Implementing pay-for-performance in primary health care: the role of institutional entrepreneurs
Authors: Smith Verna , Cumming Jackie
Published: November 2017

Institutional entrepreneurs are vital for facilitating non-incremental health policy change in complex institutional settings where established traditions and practices carry considerable weight. This paper describes a comparative case study of health policy-making which shows that Kingdon’s Multiple Streams Framework for non-incremental policy change requires enhancement to explain results in policy-making in two Westminster unitary majoritarian jurisdictions. The most similar systems comparative study found that historical, rational choice, organisational and discursive institutionalist approaches explained the policy change and variation observed better than agency-based approaches did. However, institutional entrepreneurs were important in both cases. Differences in coordinative discourse help to explain the differences in degree of change achieved in each case study and highlight the importance of discursive institutionalist approaches in bridging institutional and agency-based approaches.
Entrepreneurial failure in the transition to electric vehicles: a case study of support for sustainability policy in Israel
Authors: Cohen Nissim , Naor Michael
Published: November 2017

Why do entrepreneurs who gained initial remarkable government support for sustainability policy lose it rapidly and what may be learned from such failure? In May 2013, a national attempt for transition of transportation industry from internal combustion engine to electric vehicle by building country-wide infrastructure in Israel went bankrupt. Only short period before, the company, Better Place, seemed to be successful both in recruiting $850 million from investors and gaining institutional and political support via successful policy entrepreneurship from top governmental echelons to cut dependence on oil. The case study investigates what caused policy entrepreneur to lose political support and why the government did not provide a bailout plan for the company. Based on in-depth interviews over a period of several years with company employees and government officials in Israel and use of secondary data sources, the study concludes that, in the wake of national demonstrations for social justice in 2011, politicians shifted their agenda from national security concerns to welfare issues. This case fills a gap in the literature which tends to focus on successful ventures, by deriving insights from a case of entrepreneurial failure, as much can be learned from failure too. The practical lesson learned as the global movement for social justice spread is that initial success of policy entrepreneurship, which exploits a political window of opportunity, does not guarantee long-term governmental support for sustainability policy.
Biological invasions in aquatic ecosystems in China
Authors: Chen Yiyong , Sun Changsen , Zhan Aibin
Published: November 2017

In China, aquatic ecosystems have been highly disturbed by the introduction and spread of non-native invasive species. Unfortunately, problems of biological invasions in aquatic ecosystems have been largely overlooked and lessons from known disasters are learned slowly, despite that negative effects are frequently detected and reported. Here, we review the available literature to generate a list of invasive species in aquatic ecosystems in China. We summarize five major negative effects caused by invasive species, including habitat damage, community change, pests of agriculture and aquaculture, biodiversity loss, and genetic pollution/extinction. We discuss three major vectors (aquaculture, shipping, and aquarium and ornamental trades) responsible for the introduction and spread of aquatic invasive species. Finally, we propose and call for management of vectors responsible for the introduction and spread of invasive species in China.
Harmful non-indigenous dinoflagellate cysts in China: A review
Authors: Gao Yangchun , Dong Yanhong , Li Haitao , Zhan Aibin
Published: November 2017

Harmful dinoflagellate cysts (e.g. dinocysts) represent a great threat to marine and coastal ecosystems and even human health. As dinocysts have resistant cell walls that allow dinoflagellate species to successfully survive harsh environments, they can easily pass through multiple barriers during biological invasions and successfully colonize new locations. In introduced ranges, dinocysts often serve as seeds for harmful algal blooms, which can result in large-scale environmental disasters and economic losses. Correct identification of dinocysts represents the first step for both ecological studies and management programs. However, traditional methods, which are based on morphological observations, pose great technical challenges for dinocysts. Recent advances in molecular techniques, such as high-throughput sequencing-based metabarcoding, have tremendously revolutionized our abilities to detect marine biodiversity. Here, we summarize species composition of non-indigenous/cryptogenic dinocysts and their identification methods commonly used in China, discuss major problems in traditional morphological identification and technical issues of molecular identification, and finally propose future perspectives for the efficient identification of non-indigenous dinocysts using high-throughput sequencing-based metabarcoding. We also discuss technical issues that should be addressed before high-throughput sequencing-based metabarcoding can be widely used for dinocyst identification at large geographical scales.
Autocorrelation Structure in the Macaque Dorsolateral, But not Orbital or Polar, Prefrontal Cortex Predicts Response-Coding Strength in a Visually Cued Strategy Task
Authors: Fascianelli Valeria , Tsujimoto Satoshi , Marcos Encarni , Genovesio Aldo
Published: November 2017

In previous work, we studied the activity of neurons in the dorsolateral (PFdl), orbital (PFo), and polar (PFp) prefrontal cortex while monkeys performed a strategy task with 2 spatial goals. A cue instructed 1 of 2 strategies in each trial: stay with the previous goal or shift to the alternative goal. Each trial started with a fixation period, followed by a cue. Subsequently, a delay period was followed by a “go” signal that instructed the monkeys to choose one goal. After each choice, feedback was provided. In this study, we focused on the temporal receptive fields of the neurons, as measured by the decay in autocorrelation (time constant) during the fixation period, and examined the relationship with response and strategy coding. The temporal receptive field in PFdl correlated with the response-related but not with the strategy-related modulation in the delay and the feedback periods: neurons with longer time constants in PFdl tended to show stronger and more prolonged response coding. No such correlation was found in PFp or PFo. These findings demonstrate that the temporal specialization of neurons for temporally extended computations is predictive of response coding, and neurons in PFdl, but not PFp or PFo, develop such predictive properties.
Local production of tenascin-C acts as a trigger for monocyte/macrophage recruitment that provokes cardiac dysfunction
Authors: Abbadi Dounia , Laroumanie Fanny , Bizou Mathilde , Pozzo Joffrey , Daviaud Danièle , Delage Christine , Calise Denis , Gaits-Iacovoni Fréderique , Dutaur Marianne , Tortosa Florence , Renaud-Gabardos Edith , Douin-Echinard Victorine , Prats Anne-Catherine , Roncalli Jerome , Parini Angelo , Pizzinat Nathalie
Published: November 2017

Aims

Tenascin-C (TNC) is an endogenous danger signal molecule strongly associated with inflammatory diseases and with poor outcome in patients with cardiomyopathies. Its function within pathological cardiac tissue during pressure overload remains poorly understood.

Methods and results

We showed that TNC accumulates after 1 week of transverse aortic constriction (TAC) in the heart of 12-week-old male mice. By cross bone marrow transplantation experiments, we determined that TNC deposition relied on cardiac cells and not on haematopoietic cells. The expression of TNC induced by TAC, or by administration of a recombinant lentivector coding for TNC, triggered a pro-inflammatory cardiac microenvironment, monocyte/macrophage (MO/MΦ) accumulation, and systolic dysfunction. TNC modified macrophage polarization towards the pro-inflammatory phenotype and stimulated RhoA/Rho-associated protein kinase (ROCK) pathways to promote mesenchymal to amoeboid transition that enhanced macrophage migration into fibrillar collagen matrices. The amplification of inflammation and MO/MΦ recruitment by TNC was abrogated by genetic invalidation of TNC in knockout mice. These mice showed less ventricular remodelling and an improved cardiac function after TAC as compared with wild-type mice.

Conclusions

By promoting a pro-inflammatory microenvironment and macrophage migration, TNC appears to be a key factor to enable the MO/MΦ accumulation within fibrotic hearts leading to cardiac dysfunction. As TNC is highly expressed during inflammation and sparsely during the steady state, its inhibition could be a promising therapeutic strategy to control inflammation and immune cell infiltration in heart disease.
Recording Principles
Authors: Schomer Donald L. , Epstein Charles M. , Herman Susan T. , Maus Douglas , Fisch Bruce J.
Published: November 2017

This chapter reviews the technical aspects of recording and reviewing clinical electroencephalograms (EEGs) and related biopotentials. While advances in engineering technology have revolutionized EEG machines, the basic principles underlying accurate representation of brain activity are largely unchanged. The first section reviews the analog EEG components, and the second section discusses analog-to-digital conversion, digital filters, and display and storage parameters. Digital EEG machines are now less expensive and their capabilities far surpass those of analog machines. The third section reviews how electrode positions and systems of signal display (montages) can be used to determine the polarity and field of EEG signals. The final section describes how other biopotentials are acquired and displayed. Polygraphy can provide crucial information on other physiological processes that can impact EEG activity and can help identify potential artifactual signals. We highlight recent advances that allow the recording of a broader range of EEG frequencies and spatial distribution.
Brain Tumors and Other Space-Occupying Lesions
Authors: Hartman Adam L , Lesser Ronald P.
Published: November 2017

Brain tumors are a leading cause for new-onset seizures in adults, and many patients still present with seizures as their first manifestation of a tumor. Although at one time electroencephalography (EEG) was important for diagnosing brain tumors and other space-occupying lesions, this is now more commonly done using imaging studies, such as computed tomography and magnetic resonance imaging. However, clinical neurophysiology still is important in managing these patients. This can include the use of electrocorticography during testing to identify the seizure onset zone and eloquent cortex during resection surgeries, application of evoked potentials in assessing the location of sensorimotor cortex or the extent of tumor involvement, and the application of magnetoencephalography for both magnetic source imaging (e.g., in localizing spike-generating zones) and functional mapping. These topics will be discussed in this chapter.
Seizures and Epilepsy in Preterm and Term Neonates, Infants, Children, and Adolescents
Authors: Beal Jules C. , Eisermann Monika , Misra Sunita , Pearl Phillip L. , Plouin Perrine , Mizrahi Eli M. , Moshe Solomon L.
Published: November 2017

Children are often affected by seizure types and epilepsy syndromes that are specific to their age group and distinct from those seen in adults. At the same time, certain epilepsy syndromes affecting the adult population, such as Lennox–Gastaut syndrome and juvenile myoclonic epilepsy, often begin during childhood, as do seizures related to genetic abnormalities. The use of electroencephalography (EEG) and prolonged EEG monitoring has allowed for further insight and greater specificity in identifying and understanding seizures and epilepsy syndromes in children. This chapter reviews the role of EEG in pediatric seizures and the pediatric epilepsies, including electrographic findings in the ictal state and in the interictal period, as well as the correlation with clinical seizure semiology as it contributes to the diagnosis of epileptic phenomena. The chapter discusses EEG patterns, seizure types, and epilepsy syndromes specific to neonates, infants, children, and adolescents.
Nonconvulsive Status Epilepticus
Authors: Drislane Frank W , Herman Susan T , Kaplan Peter W
Published: November 2017

The clinical presentation and encephalographic (EEG) findings of nonconvulsive status epilepticus (NCSE) can be complicated, making diagnosis difficult. There are generalized (e.g., absence status) and focal (e.g., aphasic status, complex partial status) forms. Some patients are responsive but have cognitive or other neurologic deficits; others are less responsive or even comatose. Increasingly, the diagnosis of NCSE is considered in intensive care unit patients. Here, without clinical signs of seizures such as convulsions, EEG is critical in diagnosis, but there is uncertainty about which EEG patterns represent seizures and which clinical situations and EEG patterns warrant aggressive treatment. Antiseizure medications are tailored to the NCSE type and the clinical condition. Treatment is often easier for NCSE, and the outcome better, than for convulsive SE, but this is not always true for critically ill patients with NCSE in the ICU, for whom continuous EEG monitoring is often crucial for diagnosis and management.
Nonepileptic Events
Authors: Chen David K. , LaFrance W. Curt
Published: November 2017

Nonepileptic events (NEE) represent important differential diagnoses in patients with neurobehavioral paroxysms, especially those with apparent drug-resistant epilepsy. Errant recognition of NEE may not only subject the patient to potential complications of unnecessary epilepsy treatment, but delay the delivery of treatment that properly addresses the underlying pathology. For many patients with NEE, such as those with the conversion disorder psychogenic nonepileptic seizures (PNES) or with physiologic NEE (e.g., cardiac-induced syncope), delays in the provision of proper treatment have been shown to be associated with significant morbidity. This review focuses on clinical evaluations aiming to enhance the recognition of the different etiologies of NEE and distinguish between NEE and epilepsy, as well as between NEE of varying pathologies. Evidence-based treatments and management of NEE, particularly those pertaining to PNES, will also be discussed.
EEG in Psychiatric Disorders
Authors: Kanner Andres M. , Bermeo-Ovalle Adriana
Published: November 2017

Psychiatric symptoms are not restricted to primary psychiatric disorders and are relatively frequent in medical and neurological disorders. They may represent the clinical manifestations of these disorders, of a comorbid psychiatric disorder, or of iatrogenic complications of pharmacological and/or surgical therapies. Clearly, proper diagnosis is of the essence to provide the correct treatment. Electroencephalographic (EEG) studies are used on a regular basis to identify a potential organic cause of psychiatric symptomatology. This chapter reviews the diagnostic yield of EEG recordings in psychiatric symptomatology associated with primary psychiatric disorders, with neurological and medical conditions, and in particular with epilepsy, and provides suggestions on the optimal use of the different types of EEG recordings in clinical practice.
Standardizing EEG Interpretation and Reporting
Authors: Beniczky Sándor , Aurlien Harald , Brøgger Jan , Pressler Ronit , Hirsch Lawrence J.
Published: November 2017

This chapter describes how to standardize electroencephalographic (EEG) interpretation and reporting in clinical practice. The Standardized Computer-Based Organized Reporting of EEG (SCORE) software program was developed by an international taskforce under the auspices of the International League Against Epilepsy and the International Federation of Clinical Neurophysiology. Clinically relevant features are scored by choosing predefined terms in the software. This process automatically generates a report and at the same time builds up a database for education, quality assurance, and research. SCORE is the template used for the interactive online educational EEG platform of this textbook.
Automatic Integrated EEG Interpretation and Reporting
Authors: Shibasaki Hiroshi , Nakamura Masatoshi
Published: November 2017

Automatic interpretation of electroencephalograms (EEG) is complicated due to fluctuation of background activity, paroxysmal activities, artifacts, and use of different electrode montages. Previous attempts at automatic EEG interpretation focused on a certain feature such as background activity and paroxysmal abnormalities. The authors’ group has developed a computer-assisted, offline system for automatic comprehensive interpretation of EEG that takes into account all features of the adult waking EEG and provides the results in a written report. The system is not aimed at standardization of EEG interpretation, but its results can match the results of visual inspection by a limited number of qualified EEG-ers. Thus, this system can be adjusted in accordance with the strategy of visual inspection adopted by any EEG-er. Artifacts, spikes, and the vigilance level and attention level of subjects are automatically detected. This system can be used to supplement visual inspection and for training purposes.
Electrocorticography
Authors: Nuwer Marc R. , Schuele Stephan
Published: November 2017

Electrocorticography (ECoG) is the method of recording electroencephalographic signals directly from surgically exposed cerebral cortex. It detects intraoperatively the cortical regions with substantial epileptiform interictal discharges. Direct cortical stimulation during ECoG provides a method of identifying language, motor, and sensory regions during a craniotomy. Both techniques—the identification of cortex with epileptic activity and cortex with important eloquent functional activity—help determine limits for surgical cortical resection. These are used most commonly during epilepsy and tumor surgery. Anesthetic agents can adversely affect the recording, and ECoG restricts the types of anesthesia that can be used. The amount of spiking from diffuse or remote cortical regions on ECoG can predict the success of postoperative seizure control.
Principles and Techniques for Long-Term EEG Recording (Epilepsy Monitoring Unit, Intensive Care Unit, Ambulatory)
Authors: Nuwer Marc R , Emerson Ronald G. , Hahn Cecil D.
Published: November 2017

Long-term monitoring is a set of methods for recording electroencephalographic (EEG) signals over a period of 24 hours or longer. Patient video recording is often synchronized to the EEG. Interpretation aids help physicians to identify events, which include automated spike and seizure detection and various trending displays of frequency EEG content. These techniques are used in epilepsy monitoring units for presurgical evaluations and differential diagnosis of seizures versus nonepileptic events. They are used in intensive care units to identify nonconvulsive seizures, to measure the effectiveness of therapy, to assess depth and prognosis in coma, and other applications. The patient can be monitored at home with ambulatory monitoring equipment. Specialized training is needed for competent interpretation of long-term monitoring EEGs. Problems include false-positive events flagged by automated spike and seizure detection software, and muscle and movement artifact contamination during seizures.
Infraslow EEG Activity
Authors: Vanhatalo Sampsa , Palva J. Matias
Published: November 2017

Infraslow electroencephalographic (EEG) activity refers to frequencies below the conventional clinical EEG range that starts at about 0.5 Hz. Evidence suggests that salient EEG signals in the infraslow range are essential parts of many physiological and pathological conditions. In addition, brain is known to exhibit multitude of infraslow processes, which may be observed directly as fluctuations in the EEG signal amplitude, as infraslow fluctuations or intermittency in other neurophysiological signals, or as fluctuations in behavioural performance. Both physiological and pathological EEG activity may range from 0.01 Hz to several hundred Hz. In the clinical context, infraslow activity is commonly observed in the neonatal EEG, during and prior to epileptic seizures, and during sleep and arousals. Laboratory studies have demonstrated the presence of spontaneous infraslow EEG fluctuations or very slow event-related potentials in awake and sleeping subjects. Infraslow activity may not only arise in cortical and subcortical networks but is also likely to involve non-neuronal generators such as glial networks. The full, physiologically relevant range of brain mechanisms can be readily recorded with wide dynamic range direct-current (DC)-coupled amplifiers or full-band EEG (FbEEG). Due to the different underlying mechanisms, a single FbEEG recording can even be perceived as a multimodal recording where distinct brain modalities can be studied simultaneously by performing data analysis for different frequency ranges. FbEEG is likely to become the standard approach for a wide range of applications in both basic science and in the clinic.
Intraoperative Monitoring of Central Neurophysiology
Authors: Legatt Alan D. , Nuwer Marc R. , Emerson Ronald G.
Published: November 2017

This chapter covers neurophysiological intraoperative monitoring (NIOM). It describes the relevant neurophysiological signals, their anatomical sources, the techniques used to record them, the manner in which they are assessed, and possible causes of intraoperative signal changes. Techniques used include electroencephalography (EEG), electromyography, and auditory, somatosensory, and motor evoked potentials. Some of these techniques can be used to localize and identify areas of cerebral cortex or the corticospinal tract. Recording of the electromyogram generated by reflex activity can be used to evaluate central nervous system function in some circumstances. EEG can be used to assess depth of anesthesia. Signals can be affected by anesthesia, and the chapter discusses various anesthetic agents, their effects on signals, and considerations for anesthetic management during NIOM. Personnel performing NIOM must be knowledgeable about the anatomy and physiology underlying the signals, the technology used to record them, and the factors (including anesthesia) that can affect them.
Polysomnography
Authors: Chokroverty Sudhansu , Vertugno Roberto
Published: November 2017

This chapter covers the technical and clinical aspects of polysomnography (PSG). Section 1 includes a brief review of the historical milestones, functional neuroanatomy of sleep, physiological changes (emphasizing those pertinent to overnight PSG interpretation) and clinical relevance as well as homeostatic and circadian factors, and functions of sleep. Section 2 deals with laboratory procedures, including PSG recording and scoring techniques, indications for PSG, video-PSG, ambulatory and computerized PSG, artifacts during PSG recording, and pitfalls of PSG. Section 3 includes clinical considerations, briefly describing the clinical presentation, diagnosis, and treatment but mainly focusing on PSG findings in common sleep disorders as well as sleep-related movement disorders, neurological disorders, and sleep-related epilepsies. Section 4 addresses related laboratory procedures for the assessment of sleep, including the multiple sleep latency test, the maintenance-of-wakefulness test, and actigraphy.
Recording Techniques Related to Deep Brain Stimulation for Movement Disorders and Responsive Stimulation for Epilepsy
Authors: Shils Jay L. , Sani Sepehr , Kochanski Ryan , Kerolus Mena , Arle Jeffrey E.
Published: November 2017

Neuromodulation therapies are now common treatments for a variety of medically refractory disorders, including movement disorders and epilepsy. While surgical techniques for each disorder vary, electricity is used by both for relieving symptoms. During stereotactic placement of the stimulating electrode, either deep brain stimulation electrodes or cortical strip electrodes, intraoperative neurophysiology is used to localize the target structure. This physiology includes single-unit recordings, neurostimulation evoked response evaluation, and intracranial electroencephalography (EEG) to ensure the electrode leads are in the optimal location. Because the functional target for the responsive neurostimulator is more easily visualized on preoperative magnetic resonance imaging, intraoperative physiology is used more as a confirmatory tool, in contrast to the more functional localization-based use during electrode placement for movement disorders. This chapter discusses surgical placement of the electrodes for each procedure and the physiological guidance methodology used to place the leads in the optimal location.
Event-Related Potentials
Authors: Congendo Marco , Lopes da Silva Fernando H.
Published: November 2017

Event-related potentials (ERPs) can be elicited by a variety of stimuli and events in diverse conditions. This chapter covers the methodology of analyzing and quantifying ERPs in general. Basic models (additive, phase modulation and resetting, potential asymmetry) that account for the generation of ERPs are discussed. The principles and requirements of ensemble time averaging are presented, along with several univariate and multivariate methods that have been proposed to improve the averaging procedure: wavelet decomposition and denoising, spatial, temporal and spatio-temporal filtering. We emphasize basic concepts of principal component analysis, common spatial pattern, and blind source separation, including independent component analysis. We cover practical questions related to the averaging procedure: overlapping ERPs, correcting inter-sweep latency and amplitude variability, alternative averaging methods (e.g., median), and estimation of ERP onset. Some specific aspects of ERP analysis in the frequency domain are surveyed, along with topographic analysis, statistical testing, and classification methods.
EEG Event-Related Desynchronization and Event-Related Synchronization
Authors: Pfurtscheller Gert , Silva Fernando Lopes da
Published: November 2017

Event-related desynchronization (ERD) reflects a decrease of oscillatory activity related to internally or externally paced events. The increase of rhythmic activity is called event-related synchronization (ERS). They represent dynamical states of thalamocortical networks associated with cortical information-processing changes. This chapter discusses differences between ERD/ERS and evoked response potentials and methodologies for quantifying ERD/ERS and selecting frequency bands. It covers the interpretation of ERD/ERS in the alpha and beta bands and theta ERS and alpha ERD in behavioral tasks. ERD/ERS in scalp and subdural recordings, in various frequency bands, is discussed. Also presented is the modulation of alpha and beta rhythms by 0.1-Hz oscillations in the resting state and phase-coupling of the latter with slow changes of prefrontal hemodynamic signals (HbO2), blood pressure oscillations, and heart rate interval variations in the resting state and in relation to behavioral motor tasks. Potential uses of ERD-based strategies in stroke patients are discussed.
Brainstem Auditory Evoked Potentials and Other Auditory Evoked Potentials
Authors: Hani Abeer J. , Husain Aatif M.
Published: November 2017

Auditory evoked potentials (AEP) are used to evaluate the auditory pathways. Clinically the most useful AEPs are short-latency AEP, also known as brainstem auditory evoked potentials (BAEPs). As their name implies, BAEPs are used to assess the auditory pathways in the brainstem. This chapter focuses on BAEPs. The basic neuroanatomy of the generators of the BAEP waveforms is reviewed, followed by a detailed description of the techniques used to obtain BAEP and factors that may impact the results. A description of the interpretation and applications of BAEPs is provided with discussion of the significance of the changes in amplitude, absolute latencies, and interpeak latencies of the BAEP waveforms. An overview of other auditory evoked potentials is also provided.
Somatosensory and Pain Evoked Potentials
Authors: Mauguière François , Garcia-Larrea Luis
Published: November 2017

This chapter discusses the use of somatosensory evoked potentials (SEPs) and pain evoked potentials for diagnostic purposes. The generators of SEPs following upper limb stimulation have been identified through intracranial recordings, permitting the analysis of somatosensory disorders caused by neurological diseases. Laser activation of fibers involved in thermal and pain sensation has extended the applications of evoked potentials to neuropathic pain disorders. Knowledge of the effects of motor programming, paired stimulations, and simultaneous stimulation of adjacent somatic territories has broadened SEP use in movement disorders. The recording of high-frequency cortical oscillations evoked by peripheral nerve stimulation gives access to the functioning of SI area neuronal circuitry. SEPs complement electro-neuro-myography in patients with neuropathies and radiculopathies, spinal cord and hemispheric lesions, and coma. Neuroimaging has overtaken SEPs in detecting and localizing central nervous system lesions, but SEPs still permit assessment of somatosensory and pain disorders that remain unexplained by anatomical investigations.
Neurocognitive Processes
Authors: Lopes da Silva Fernando H. , Halgren Eric
Published: November 2017

Transmembrane neuronal currents that embody cognition in the cortex produce magnetoencephalographic and electroencephalographic signals. Frequency-domain analysis reveals standard rhythms with consistent topography, frequency, and cognitive correlates. Time-domain analysis reveals average event-related potentials and field (ERP/ERF) components with consistent topography, latency, and cognitive correlates. Standard rhythms and ERP/ERF components underlie perceiving stimuli; evaluating whether stimuli match predictions, and taking appropriate action when they do not; encoding stimuli to permit semantic processing and then accessing lexical representations and assigning syntactic roles; maintaining information in primary memory; preparing to take an action; and closing processing of an event–response sequence. Sustained mental processes are associated with theta and gamma. Consolidating memories appears to occur mainly during replay of specific firing patterns during sleep spindles and slow oscillations. Biophysical, neuroanatomical, and neurophysiological factors interact to render cognitive rhythms and components particularly sensitive to the large-scale modulatory processes that sequence and integrate higher cortical processing.
The Comprehensive Narrative-Crisis Model of Suicide
Authors: Briggs Jessica
Published: November 2017

The narrative crisis model of suicide posits that individuals attempt suicide when they experience a distinct emotional state termed the suicide crisis syndrome. This chapter describes the model, which has three components: trait vulnerability, suicidal narrative, and the suicidal crisis syndrome. Trait vulnerability includes all static risk factors, which are relatively stable over time and distal to acute suicidal behavior. Suicidal narrative describes a suicidal person’s perception of his or her life story in which the past has led to an intolerable present and a future that is unimaginable. The suicidal crisis syndrome (SCS) is a distinct emotional state characterized by entrapment, affective dysregulation, and loss of cognitive control. The result is the suicidal act, brought on by an emotional urge to end the intolerable mental pain of SCS. Imminent suicide risk is primarily determined by SCS intensity, to which both trait vulnerability and the suicidal narrative also contribute independently.
Stressful Life Events
Authors: Linzer Shoshana , Chesir Adina , Ginsburg Tal , Varas Olivia
Published: November 2017

Stressful life events often occur during the week or month preceding suicide and may aid both the formation of the suicidal narrative and the triggering of the suicide crisis syndrome. This chapter examines the stressors that have been linked to imminent suicidal behavior. The chapter has five sections. The work and career section describes imminent risk associated with economic hardship, business/work failures, and home loss. The relationship conflict section discusses suicide risks stemming from romantic rejection, intimate relationship and family conflicts, as well as abuse, neglect, and bullying. The serious medical illness section discusses suicide risks associated with diagnosis and chronicity of being critically ill. The serious mental illness section focuses on imminent risk associated with recent diagnosis, acuity and hospitalization for mental illness, as well the risks following recent failed suicide attempts. The recent substance misuse section assesses imminent risk associated with chronic alcohol/drug use, acute intoxication, and withdrawal.