Automatic identification of sleep and wakefulness using single-channel EEG and respiratory polygraphy signals for the diagnosis of obstructive sleep apnea

Polysomnography (PSG) is necessary for the accurate estimation of total sleep time (TST) and the calculation of the apnea-hypopnea index (AHI). In type III home sleep apnea testing (HSAT), TST is overestimated because of the lack of electrophysiological sleep recordings. The aim of this study was to evaluate the accuracy and reliability of a novel automated sleep/wake scoring algorithm combining a single electroencephalogram (EEG) channel with actimetry and HSAT signals. The study included 160 patients investigated by PSG for suspected obstructive sleep apnea (OSA). Each PSG was recorded and scored manually using American Academy of Sleep Medicine (AASM) rules. The automatic sleep/wake-scoring algorithm was based on a single-channel EEG (FP2-A1) and the variability analysis of HSAT signals (airflow, snoring, actimetry, light and respiratory inductive plethysmography). Optimal detection thresholds were derived for each signal using a training set. Automatic and manual scorings were then compared epoch by epoch considering two states (sleep and wake). Cohen\u27s kappa coefficient between the manual scoring and the proposed automatic algorithm was substantial, 0.74 ± 0.18, in separating wakefulness and sleep. The sensitivity, specificity and the positive and negative predictive values for the detection of wakefulness were 76.51% ± 21.67%, 95.48% ± 5.27%, 81.84% ± 15.42% and 93.85% ± 6.23% respectively. Compared with HSAT signals alone, AHI increased by 22.12% and 27 patients changed categories of OSA severity with the automatic sleep/wake-scoring algorithm. Automatic sleep/wake detection using a single-channel EEG combined with HSAT signals was a reliable method for TST estimation and improved AHI calculation compared with HSAT

Factors Influencing Performance of Internet-Based Biosurveillance Systems Used in Epidemic Intelligence for Early Detection of Infectious Diseases Outbreaks

Background: Internet-based biosurveillance systems have been developed to detect health threats using information available on the Internet, but system performance has not been assessed relative to end-user needs and perspectives. Method and Findings Infectious disease events from the French Institute for Public Health Surveillance (InVS) weekly international epidemiological bulletin published in 2010 were used to construct the gold-standard official dataset. Data from six biosurveillance systems were used to detect raw signals (infectious disease events from informal Internet sources): Argus, BioCaster, GPHIN, HealthMap, MedISys and ProMED-mail. Crude detection rates (C-DR), crude sensitivity rates (C-Se) and intrinsic sensitivity rates (I-Se) were calculated from multivariable regressions to evaluate the systems’ performance (events detected compared to the gold-standard) 472 raw signals (Internet disease reports) related to the 86 events included in the gold-standard data set were retrieved from the six systems. 84 events were detected before their publication in the gold-standard. The type of sources utilised by the systems varied significantly (p<0001). I-Se varied significantly from 43% to 71% (p = 0001) whereas other indicators were similar (C-DR: p = 020; C-Se, p = 013). I-Se was significantly associated with individual systems, types of system, languages, regions of occurrence, and types of infectious disease. Conversely, no statistical difference of C-DR was observed after adjustment for other variables. Conclusion: Although differences could result from a biosurveillance system's conceptual design, findings suggest that the combined expertise amongst systems enhances early detection performance for detection of infectious diseases. While all systems showed similar early detection performance, systems including human moderation were found to have a 53% higher I-Se (p = 00001) after adjustment for other variables. Overall, the use of moderation, sources, languages, regions of occurrence, and types of cases were found to influence system performance

Self-defined residential neighbourhoods: size variations and correlates across five European urban regions.

The neighbourhood is recognized as an important unit of analysis in research on the relation between obesogenic environments and development of obesity. One important challenge is to define the limits of the residential neighbourhood, as perceived by study participants themselves, in order to improve our understanding of the interaction between contextual features and patterns of obesity. An innovative tool was developed in the framework of the SPOTLIGHT project to identify the boundaries of neighbourhoods as defined by participants in five European urban regions. The aims of this study were (i) to describe self-defined neighbourhood (size and overlap with predefined residential area) according to the characteristics of the sampling administrative neighbourhoods (residential density and socioeconomic status) within the five study regions and (ii) to determine which individual or/and environmental factors are associated with variations in size of self-defined neighbourhoods. Self-defined neighbourhood size varies according to both individual factors (age, educational level, length of residence and attachment to neighbourhood) and contextual factors. These findings have consequences for how residential neighbourhoods are defined and operationalized and can inform how self-defined neighbourhoods may be used in research on associations between contextual characteristics and health outcomes such as obesity

Statistical Computing on Non-Linear Spaces for Computational Anatomy

International audienceComputational anatomy is an emerging discipline that aims at analyzing and modeling the individual anatomy of organs and their biological variability across a population. However, understanding and modeling the shape of organs is made difficult by the absence of physical models for comparing different subjects, the complexity of shapes, and the high number of degrees of freedom implied. Moreover, the geometric nature of the anatomical features usually extracted raises the need for statistics on objects like curves, surfaces and deformations that do not belong to standard Euclidean spaces. We explain in this chapter how the Riemannian structure can provide a powerful framework to build generic statistical computing tools. We show that few computational tools derive for each Riemannian metric can be used in practice as the basic atoms to build more complex generic algorithms such as interpolation, filtering and anisotropic diffusion on fields of geometric features. This computational framework is illustrated with the analysis of the shape of the scoliotic spine and the modeling of the brain variability from sulcal lines where the results suggest new anatomical findings

Increased liver stiffness in patients with severe sleep apnoea and metabolic comorbidities

The goal of this study was to assess the relationship between the severity of obstructive sleep apnoea (OSA) and liver stiffness measurement (LSM), one of the most accurate noninvasive screening tools for liver fibrosis in nonalcoholic fatty liver disease.The study included 147 patients with at least one criterion for the metabolic syndrome, assessed by polysomnography for suspected OSA. LSM was performed using transient elastography (FibroScan). Significant liver disease and advanced liver fibrosis were defined as LSM ≥7.3 and ≥9.6 kPa, respectively.23 patients were excluded because of unreliable LSM. Among 124 patients, 34 (27.4%) had mild OSA, 38 (30.6%) had moderate OSA and 52 (42.0%) had severe OSA. LSM values were 7.3- &lt;9.6 kPa in 18 (14.5%) patients and ≥9.6 kPa in 15 (12.1%) patients. A dose-response relationship was observed between OSA severity and LSM values (p=0.004). After adjustment for age, sex, metabolic syndrome and insulin resistance, severe OSA was associated with an increased risk of LSM ≥7.3 kPa (OR 7.17, 95% CI 2.51-20.50) and LSM ≥9.6 kPa (OR 4.73, 95% CI 1.25-17.88).In patients with metabolic comorbidities, severe OSA is independently associated with increased liver stiffness, which may predispose to a higher risk of significant liver disease and poorer prognosis

Independent association between obstructive sleep apnea severity and glycated hemoglobin in adults without diabetes

OBJECTIVE: We tested the hypothesis of an independent cross-sectional association between obstructive sleep apnea (OSA) severity and glycated hemoglobin (HbA(1c)) in adults without known diabetes. RESEARCH DESIGN AND METHODS: HbA(1c) was measured in whole-blood samples from 2,139 patients undergoing nocturnal recording for suspected OSA. Participants with self-reported diabetes, use of diabetes medication, or HbA(1c) value ≥6.5% were excluded from this study. Our final sample size comprised 1,599 patients. RESULTS: A dose-response relationship was observed between apnea-hypopnea index (AHI) and the percentage of patients with HbA(1c) &gt;6.0%, ranging from 10.8% for AHI &lt;5 to 34.2% for AHI ≥50. After adjustment for age, sex, smoking habits, BMI, waist circumference, cardiovascular morbidity, daytime sleepiness, depression, insomnia, sleep duration, and study site, odds ratios (95% CIs) for HbA(1c) &gt;6.0% were 1 (reference), 1.40 (0.84-2.32), 1.80 (1.19-2.72), 2.02 (1.31-3.14), and 2.96 (1.58-5.54) for AHI values &lt;5, 5 to &lt;15, 15 to &lt;30, 30 to &lt;50, and ≥50, respectively. Increasing hypoxemia during sleep was also independently associated with the odds of HbA(1c) &gt;6.0%. CONCLUSIONS: Among adults without known diabetes, increasing OSA severity is independently associated with impaired glucose metabolism, as assessed by higher HbA(1c) values, which may expose them to higher risks of diabetes and cardiovascular disease

Trajectoires : une application mobile pour le contrôle et l’écriture de la spatialisation sonore

International audienceIn this paper, we explore the potential of mobile devices for the control and the composition of sound spatialization. We conducted interviews with four composers to understand their needs and guide the design of a new mobile application that allows the drawing of sound sources trajectories. We describe three collaborations with composers who appropriated the application to create trajectories and integrate them into their creations.Dans cet article, nous explorons les possibilités offertes par les dispositifs mobiles pour le contrôle et l'écriture de la spatialisation sonore. Nous avons réalisé des entre-tiens avec quatre compositeurs pour comprendre leurs besoins et guider la conception d'une nouvelle application mobile permettant le dessin de trajectoires de sources sonores. Nous décrivons des collaborations avec trois compositeurs qui se sont appropriés l'application pour créer des trajectoires et les intégrer dans leurs créations

Need and importance of health protection training in Nepal

By investing in health protection, the health of the nation can be safeguarded from future threats of uncontrolled infectious disease epidemics and disasters

Reduction of nucleosome assembly during new DNA synthesis impairs both major pathways of double-strand break repair

Assembly of new chromatin during S phase requires the histone chaperone complexes CAF-1 (Cac2p, Msi1p and Rlf2p) and RCAF (Asf1p plus acetylated histones H3 and H4). Cells lacking CAF-1 and RCAF are hypersensitive to DNA-damaging agents, such as methyl methanesulfonate and camptothecin, suggesting a possible defect in double-strand break (DSB) repair. Assays developed to quantitate repair of defined, cohesive-ended break structures revealed that DSB-induced plasmid:chromosome recombination was reduced ∼10-fold in RCAF/CAF-1 double mutants. Recombination defects were similar with both chromosomal and plasmid targets in vivo, suggesting that inhibitory chromatin structures were not involved. Consistent with these observations, ionizing radiation-induced loss of heterozygosity was abolished in the mutants. Nonhomologous end-joining (NHEJ) repair proficiency and accuracy were intermediate between wild-type levels and those of NHEJ-deficient yku70 and rad50 mutants. The defects in NHEJ, but not homologous recombination, could be rescued by deletion of HMR-a1, a component of the a1/alpha2 transcriptional repressor complex. The findings are consistent with the observation that silent mating loci are partially derepressed. These results demonstrate that defective assembly of nucleosomes during new DNA synthesis compromises each of the known pathways of DSB repair and that the effects can be indirect consequences of changes in silenced chromatin structure