221 research outputs found
Altered rich club and frequency-dependent subnetworks organization in mild traumatic brain injury: A MEG resting-state study
Functional brain connectivity networks exhibit “small-world” characteristics and some
of these networks follow a “rich-club” organization, whereby a few nodes of high
connectivity (hubs) tend to connect more densely among themselves than to nodes
of lower connectivity. The Current study followed an “attack strategy” to compare the
rich-club and small-world network organization models using Magnetoencephalographic
(MEG) recordings from mild traumatic brain injury (mTBI) patients and neurologically
healthy controls to identify the topology that describes the underlying intrinsic brain
network organization. We hypothesized that the reduction in global efficiency caused
by an attack targeting a model’s hubs would reveal the “true” underlying topological
organization. Connectivity networks were estimated using mutual information as
the basis for cross-frequency coupling. Our results revealed a prominent rich-club
network organization for both groups. In particular, mTBI patients demonstrated hypersynchronization
among rich-club hubs compared to controls in the d band and the
d-g1, "-g1, and b-g2 frequency pairs. Moreover, rich-club hubs in mTBI patients
were overrepresented in right frontal brain areas, from " to g1 frequencies, and
underrepresented in left occipital regions in the d-b, d-g1, "-b, and b-g2 frequency pairs.
These findings indicate that the rich-club organization of resting-state MEG, considering
its role in information integration and its vulnerability to various disorders like mTBI, may
have a significant predictive value in the development of reliable biomarkers to help the
validation of the recovery frommTBI. Furthermore, the proposed approachmight be used
as a validation tool to assess patient recovery
Parametric and Nonparametric EEG Analysis for the Evaluation of EEG Activity in Young Children with Controlled Epilepsy
There is an important evidence of differences in the EEG frequency spectrum of control subjects as compared to epileptic subjects. In particular, the study of children presents difficulties due to the early stages of brain development and the various forms of epilepsy indications. In this study, we consider children that developed epileptic crises in the past but without any other clinical, psychological, or visible neurophysiological findings. The aim of the paper is to develop reliable techniques for testing if such controlled epilepsy induces related spectral differences in the EEG. Spectral features extracted by using nonparametric, signal representation techniques (Fourier and wavelet transform) and a parametric, signal modeling technique (ARMA) are compared and their effect on the classification of the two groups is analyzed. The subjects performed two different tasks: a control (rest) task and a relatively difficult math task. The results show that spectral features extracted by modeling the EEG signals recorded from individual channels by an ARMA model give a higher discrimination between the two subject groups for the control task, where classification scores of up to 100% were obtained with a linear discriminant classifier
Deep-PowerX: A Deep Learning-Based Framework for Low-Power Approximate Logic Synthesis
This paper aims at integrating three powerful techniques namely Deep
Learning, Approximate Computing, and Low Power Design into a strategy to
optimize logic at the synthesis level. We utilize advances in deep learning to
guide an approximate logic synthesis engine to minimize the dynamic power
consumption of a given digital CMOS circuit, subject to a predetermined error
rate at the primary outputs. Our framework, Deep-PowerX, focuses on replacing
or removing gates on a technology-mapped network and uses a Deep Neural Network
(DNN) to predict error rates at primary outputs of the circuit when a specific
part of the netlist is approximated. The primary goal of Deep-PowerX is to
reduce the dynamic power whereas area reduction serves as a secondary
objective. Using the said DNN, Deep-PowerX is able to reduce the exponential
time complexity of standard approximate logic synthesis to linear time.
Experiments are done on numerous open source benchmark circuits. Results show
significant reduction in power and area by up to 1.47 times and 1.43 times
compared to exact solutions and by up to 22% and 27% compared to
state-of-the-art approximate logic synthesis tools while having orders of
magnitudes lower run-time
Review on solving the inverse problem in EEG source analysis
In this primer, we give a review of the inverse problem for EEG source localization.
This is intended for the researchers new in the field to get insight in the
state-of-the-art techniques used to find approximate solutions of the brain sources
giving rise to a scalp potential recording. Furthermore, a review of the performance
results of the different techniques is provided to compare these different inverse
solutions. The authors also include the results of a Monte-Carlo analysis which they
performed to compare four non parametric algorithms and hence contribute to what is
presently recorded in the literature. An extensive list of references to the work of
other researchers is also provided
A decision support framework for the discrimination of children with controlled epilepsy based on EEG analysis
This work was supported in part by the EC-IST project Biopattern, contract no:
508803, by the EC ICT project TUMOR, contract no: 247754, by the University of
Malta grant LBA-73-695, by an internal grant from the Technical University of
Crete, ELKE# 80037 and by the Academy of Finland, project nos: 113572,
118355, 134767 and 213462.Background: In this work we consider hidden signs (biomarkers) in ongoing EEG activity expressing epileptic
tendency, for otherwise normal brain operation. More specifically, this study considers children with controlled
epilepsy where only a few seizures without complications were noted before starting medication and who showed no
clinical or electrophysiological signs of brain dysfunction. We compare EEG recordings from controlled epileptic
children with age-matched control children under two different operations, an eyes closed rest condition and a
mathematical task. The aim of this study is to develop reliable techniques for the extraction of biomarkers from EEG
that indicate the presence of minor neurophysiological signs in cases where no clinical or significant EEG abnormalities
are observed.
Methods: We compare two different approaches for localizing activity differences and retrieving relevant information
for classifying the two groups. The first approach focuses on power spectrum analysis whereas the second approach
analyzes the functional coupling of cortical assemblies using linear synchronization techniques.
Results: Differences could be detected during the control (rest) task, but not on the more demanding mathematical
task. The spectral markers provide better diagnostic ability than their synchronization counterparts, even though a
combination (or fusion) of both is needed for efficient classification of subjects.
Conclusions: Based on these differences, the study proposes concrete biomarkers that can be used in a decision
support system for clinical validation. Fusion of selected biomarkers in the Theta and Alpha bands resulted in an
increase of the classification score up to 80% during the rest condition. No significant discrimination was achieved
during the performance of a mathematical subtraction task.peer-reviewe
Review of the Commission Decision 2010/477/EU concerning MSFD criteria for assessing Good Environmental Status, Descriptor 7
This report represents the result of the scientific and technical review of Commission Decision 2010/477/EU in relation to Descriptor 7. The review has been carried out by the EC JRC together with experts nominated by EU Member States, and has considered contributions from the GES Working Group in accordance with the roadmap set out in the MSFD implementation strategy (agreed on at the 11th CIS MSCG meeting).
The report is one of a series of reports (review manuals) including Descriptor 1, 2, 5, 7, 8, 9, 10 that conclude phase 1 of the review process and, as agreed within the MSFD Common Implementation Strategy, are the basis for review phase 2, towards an eventual revision of the Commission Decision 2010/477/EU.
The report presents the state of the technical discussions as of 30 April 2015 (document version 7.0: ComDecRev_D7_V7.0_FINAL.docx), as some discussions are ongoing, it does not contain agreed conclusions on all issues.
The document does not represent an official, formal position of any of the Member States and the views expressed in the document are not to be taken as representing the views of the European Commission.JRC.H.1-Water Resource
Comparison of single trial back-projected independent components with the averaged waveform for the extraction of biomarkers of auditory P300 EPs
The independent components analysis (ICA) of the auditory P300 evoked responses in the EEG of normal subjects is described. The purpose was to identify any features which might provide the basis for biomarkers for diseases, such as Alzheimer’s disease. Single trial P300s were analysed by ICA, the activations were back-projected to scalp electrodes, many artefactual components were removed automatically, and the back-projected independent components (BICs) were first clustered according to their amplitudes and latencies. Then these primary clusters were secondarily clustered according to the columns of their mixing matrices, which clusters together those BICs with the same scalp topographies and, therefore, source locations. The BICs comprising the P300s had simple shapes, approximating half-sinusoids. Trial- to-trial variations in the BICs were found, which explain why different averages have been reported. Both positive- and also negative-going BICs were identified, some associated with known peaks in the P300 waveform. Artefact-free, single trial P300 waveforms could be constructed from the BICs, but these are probably of less interest than the BICs themselves. The findings demonstrate that neither averaged P300s, nor single trial P300s, are reliable as biomarkers, but rather it will be necessary to investigate the BICs present in a number of single trial realizations.peer-reviewe
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Mediterranean Sea response to climate change in an ensemble of twenty first century scenarios
The Mediterranean climate is expected to become warmer and drier during the twenty-first century. Mediterranean Sea response to climate change could be modulated by the choice of the socio-economic scenario as well as the choice of the boundary conditions mainly the Atlantic hydrography, the river runoff and the atmospheric fluxes. To assess and quantify the sensitivity of the Mediterranean Sea to the twenty-first century climate change, a set of numerical experiments was carried out with the regional ocean model NEMOMED8 set up for the Mediterranean Sea. The model is forced by air–sea fluxes derived from the regional climate model ARPEGE-Climate at a 50-km horizontal resolution. Historical simulations representing the climate of the period 1961–2000 were run to obtain a reference state. From this baseline, various sensitivity experiments were performed for the period 2001–2099, following different socio-economic scenarios based on the Special Report on Emissions Scenarios. For the A2 scenario, the main three boundary forcings (river runoff, near-Atlantic water hydrography and air–sea fluxes) were changed one by one to better identify the role of each forcing in the way the ocean responds to climate change. In two additional simulations (A1B, B1), the scenario is changed, allowing to quantify the socio-economic uncertainty. Our 6-member scenario simulations display a warming and saltening of the Mediterranean. For the 2070–2099 period compared to 1961–1990, the sea surface temperature anomalies range from +1.73 to +2.97 °C and the SSS anomalies spread from +0.48 to +0.89. In most of the cases, we found that the future Mediterranean thermohaline circulation (MTHC) tends to reach a situation similar to the eastern Mediterranean Transient. However, this response is varying depending on the chosen boundary conditions and socio-economic scenarios. Our numerical experiments suggest that the choice of the near-Atlantic surface water evolution, which is very uncertain in General Circulation Models, has the largest impact on the evolution of the Mediterranean water masses, followed by the choice of the socio-economic scenario. The choice of river runoff and atmospheric forcing both have a smaller impact. The state of the MTHC during the historical period is found to have a large influence on the transfer of surface anomalies toward depth. Besides, subsurface currents are substantially modified in the Ionian Sea and the Balearic region. Finally, the response of thermosteric sea level ranges from +34 to +49 cm (2070–2099 vs. 1961–1990), mainly depending on the Atlantic forcing
Habitat Selection and Temporal Abundance Fluctuations of Demersal Cartilaginous Species in the Aegean Sea (Eastern Mediterranean)
Predicting the occurrence of keystone top predators in a multispecies marine environment, such as the Mediterranean Sea, can be of considerable value to the long-term sustainable development of the fishing industry and to the protection of biodiversity. We analysed fisheries independent scientific bottom trawl survey data of two of the most abundant cartilaginous fish species (Scyliorhinus canicula, Raja clavata) in the Aegean Sea covering an 11-year sampling period. The current findings revealed a declining trend in R. clavata and S. canicula abundance from the late ′90 s until 2004. Habitats with the higher probability of finding cartilaginous fish present were those located in intermediate waters (depth: 200–400 m). The present results also indicated a preferential species' clustering in specific geographic and bathymetric regions of the Aegean Sea. Depth appeared to be one of the key determining factors for the selection of habitats for all species examined. With cartilaginous fish species being among the more biologically sensitive fish species taken in European marine fisheries, our findings, which are based on a standardized scientific survey, can contribute to the rational exploitation and management of their stocks by providing important information on temporal abundance trends and habitat preferences
B-cell receptor sequencing of anti-citrullinated protein antibody (ACPA) IgG-expressing B cells indicates a selective advantage for the introduction of N-glycosylation sites during somatic hypermutation
Immunobiology of allogeneic stem cell transplantation and immunotherapy of hematological disease
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