34 research outputs found

    Characterization of K-Complexes and Slow Wave Activity in a Neural Mass Model

    Get PDF
    NREM sleep is characterized by two hallmarks, namely K-complexes (KCs) during sleep stage N2 and cortical slow oscillations (SOs) during sleep stage N3. While the underlying dynamics on the neuronal level is well known and can be easily measured, the resulting behavior on the macroscopic population level remains unclear. On the basis of an extended neural mass model of the cortex, we suggest a new interpretation of the mechanisms responsible for the generation of KCs and SOs. As the cortex transitions from wake to deep sleep, in our model it approaches an oscillatory regime via a Hopf bifurcation. Importantly, there is a canard phenomenon arising from a homoclinic bifurcation, whose orbit determines the shape of large amplitude SOs. A KC corresponds to a single excursion along the homoclinic orbit, while SOs are noise-driven oscillations around a stable focus. The model generates both time series and spectra that strikingly resemble real electroencephalogram data and points out possible differences between the different stages of natural sleep

    Emotional and Behavioral Problems in Children Living With Addicted Family Members: Prevention Challenges in an Underprivileged Suburban Community

    Get PDF
    Abstract Children living with substance abusers are more likely to experience negative outcomes. Our goal was to compare caregivers' reports on the Child Behavior Checklist (CBCL) and a socioeconomic and risk form of psychological aspects of children exposed to substance abuse assisted versus not assisted by a preventive intervention program in an underprivileged community. This observational intervention study was conducted with 66 caregivers of children who attended the program and 35 caregivers of children from the same community who did not attend. Ages ranged between six and 11 years old. Chi-square and logistic regression tests indicate that children exposed to substance abusers have more mental health problems than the general population and those who did not participate in the preventive intervention program presented worse outcomes, with higher rates of behavioral/emotional problems and exposure to risk situations. Results suggest that preventive actions might be helpful to promote the mental health of children at risk, validating the need for public policies and services

    Planck 2015 results I. Overview of products and scientific results

    Get PDF
    The European Space Agency's Planck satellite, which is dedicated to studying the early Universe and its subsequent evolution, was launched on 14 May 2009. It scanned the microwave and submillimetre sky continuously between 12 August 2009 and 23 October 2013. In February 2015, ESA and the Planck Collaboration released the second set of cosmology products based on data from the entire Planck mission, including both temperature and polarization, along with a set of scientific and technical papers and a web-based explanatory supplement. This paper gives an overview of the main characteristics of the data and the data products in the release, as well as the associated cosmological and astrophysical science results and papers. The data products include maps of the cosmic microwave background (CMB), the thermal Sunyaev-Zeldovich effect, diffuse foregrounds in temperature and polarization, catalogues of compact Galactic and extragalactic sources (including separate catalogues of Sunyaev-Zeldovich clusters and Galactic cold clumps), and extensive simulations of signals and noise used in assessing uncertainties and the performance of the analysis methods. The likelihood code used to assess cosmological models against the Planck data is described, along with a CMB lensing likelihood. Scientific results include cosmological parameters derived from CMB power spectra, gravitational lensing, and cluster counts, as well as constraints on inflation, non-Gaussianity, primordial magnetic fields, dark energy, and modified gravity, and new results on low-frequency Galactic foregrounds

    Toward precision medicine of breast cancer

    Full text link

    Efeitos da Reeducação Postural Global em escolares com escoliose Global Posture Reeducation effects in students with scoliosis

    Get PDF
    O objetivo deste estudo foi analisar o efeito do método da Reeducação Postural Global (RPG) em escolares com diagnóstico de escoliose torácica não estrutural (ETNE). Os escolares com indicativo de ETNE ao exame postural e teste de Adams negativo foram encaminhados ao exame radiográfico para comprovação diagnóstica. Foram selecionados 20 participantes (11 meninos e 9 meninas, com 10±3 anos), divididos randomicamente em dois grupos homogêneos: o que realizou o RPG (GRPG) durante 12 semanas com duração de 25 a 30 minutos cada sessão, de acordo com o que aguentou permanecer na postura; e o grupo controle (GC), sem intervenção. Após três meses, os dois grupos repetiram a avaliação postural e o exame radiográfico. Para avaliação das estatísticas, foi utilizada análise de variância (ANOVA) univariada, com medidas repetidas, seguida do Post Hoc de Tukey para identificar as possíveis diferenças intra e intergrupos. O valor de &#945; foi de 0,05. O GRPG apresentou redução significativa no ângulo de Cobb na comparação intragrupo (&#916;%=-35,100; p=0,009), mas o GC não (&#916;%=9,520; p=0,789). Pode-se concluir que escolares submetidos ao método da RPG apresentaram melhora do quadro de escoliose torácica não estrutural.<br>The aim of this study was to analyze the effect of Global Reeducation Postural (RPG) method in scholars diagnosed with thoracic nonstructural scoliosis (ETNE). Scholars with indicative of ETNE to postural exam and Adams test negative were directed to radiographic exam to diagnostic. Twenty participants were selected (11 boys and 9 girls, 10±3 years old) and randomly divided in two homogeneous groups: group treated by RPG (GRPG) and control group (CG). The GRPG was submitted a RPG treatment during 12 weeks in sessions from 25 to 30 minutes in agreement with each student tolerance at posture. The CG didn't suffer intervention. After three months, both groups repeated the postural and radiographic exam. For statistics, it was used ANOVA univariated with repeated measures, followed by Tukey Post Hoc Test to identify the possible differences intra and intergroups. The &#945; value used was 0.05. The GRPG present significant reduction at Cobb angle between pre and posttest (&#916;%=-35.100; p=0.009), but the CG didn´t show (&#916;%=9.520; p=0.789). It was concluded that scholars submitted to RPG method presented improvement in thoracic nonstructural scoliosis
    corecore