A novel underdetermined source recovery algorithm based on k-sparse component analysis

Sparse component analysis (SCA) is a popular method for addressing underdetermined blind source separation in array signal processing applications. We are motivated by problems that arise in the applications where the sources are densely sparse (i.e. the number of active sources is high and very close to the number of sensors). The separation performance of current underdetermined source recovery (USR) solutions, including the relaxation and greedy families, reduces with decreasing the mixing system dimension and increasing the sparsity level (k). In this paper, we present a k-SCA-based algorithm that is suitable for USR in low-dimensional mixing systems. Assuming the sources is at most (m−1) sparse where m is the number of mixtures; the proposed method is capable of recovering the sources from the mixtures given the mixing matrix using a subspace detection framework. Simulation results show that the proposed algorithm achieves better separation performance in k-SCA conditions compared to state-of-the-art USR algorithms such as basis pursuit, minimizing norm-L1, smoothed L0, focal underdetermined system solver and orthogonal matching pursuit

Elevated Blood-Based Brain Biomarker Levels in Patients with Epileptic Seizures: A Systematic Review and Meta-analysis

Recently, growing attention has been paid to the changes of brain biomarkers following the epilepsy. However, establishing specific epilepsy-related biomarkers has been impeded due to contradictory findings. This study systematically reviewed the evidence on brain biomarkers in epilepsy and determined reliable biomarkers in epileptic patients. A comprehensive systematic search of online databases was performed to find eligible studies up to August 2019. The quality of studies methodologically was assessed using the Newcastle-Ottawa Scale score. Among the several biomarkers, S100 calcium binding protein B (S100B) and neuron specific enolase (NSE) have been qualified for meta-analysis of the association between epilepsy and the brain biomarkers. Inverse-variance weights method was used to calculate pooled standardized mean difference (SMD) estimate with 95 CI, and random effects meta-analysis was conducted taking into account conceptual heterogeneity. Sensitivity analysis and publication bias assessment was performed using Stata. Of 29 studies that were qualified for further analysis, only 22 studies were eligible to quantify by meta-analysis. Significant increase of serum S100B levels (SMD = 0.80; 95 CI 0.18 to 1.42) but not NSE (SMD = 0.45; 95 CI -0.09 to 1.00) has been found in epileptic patients compared with healthy controls. Subgroup meta-analysis by age demonstrated that S100B could be found in pediatric (SMD = 1.15; 95 CI 0.03 to 2.27) not adult patients (SMD = 0.43; 95 CI -0.12 to 0.98). Findings of this meta-analysis indicate that serum level of S100B is significantly increased in epileptic patients, suggesting the elevation and release of the brain biomarkers from brain to blood following epileptic seizures. © 2020 American Chemical Society

M. Pierre-Yves GUMERY

Thèse dirigée par Christian JUTTEN et codirigée par Bertrand RIVET préparée au sein du laboratoire Grenoble, images, parole, signal, automatique (GIPSA-lab) dans l’école doctorale d’électronique, électrotechnique, automatique et traitement du signal (EEATS) Extraction et débruitage de signaux ECG du fœtus Thèse soutenue publiquement le 7 Novembre 2013, devant le jury composé de

Axonal transport proteins and depressive like behavior, following Chronic Unpredictable Mild Stress in male rat

Background: A common mood disorder, depression has long been considered a leading cause of disability worldwide. Chronic stress is involved in the development of various psychiatric diseases including major depressive disorder. Stress can induce depressive-like symptoms and initiate neurodegenerative processes in the brain. The neurodegenerative theory of depression holds impaired axonal transport as a negative factor in neural survival. Axonal transport is a critical mechanism for normal neuronal function, playing crucial roles in axon growth, neurotransmitter secretion, normal mitochondrial function and neural survival. Methods and materials: To investigate the effects of stress-induced depression, in the present study, we evaluated behavior by forced swimming test (FST), corticosterone plasma level by ELISA assay, hippocampal mRNA expression of three genes (NGF, kinesin and dynein) via real-time PCR and hippocamp count by Nissl staining in male Wistar rats. Results: Our data demonstrated a significant decrease in the expression of NGF, kinesin and dynein genes in CUMS groups compared to the control group (non-stressed) (p < 0.05). CUMS also caused an elevation in immobility time and corticosterone plasma level in the stressed group compared to the controls (p < 0.01 and p < 0.05, respectively). Conclusion: The results suggested that the possibility of stress-induced depressive behavior associated with hippocampal neurodegeneration process is correlated with a low expression of kinesin and dynein, the two most important proteins in axonal transport. © 2018 Elsevier Inc

Comparison of the Adulthood Chronic Stress Effect on Hippocampal BDNF Signaling in Male and Female Rats

Studies show that gender plays an important role in stress-related disorders, and women are more vulnerable to its effect. The present study was undertaken to investigate differences in the change in expression of brain-derived neurotrophic factor (BDNF), and its tyrosine intracellular kinase-activating receptor (TrkB) genes in the male and female rats� hippocampus (HPC) under chronic mild repeated stress (CMRS) conditions. In this experiment, male and female Wistar rats were randomly divided into two groups: the CMRS and the control group. To induce stress, a repeated forced swimming paradigm was employed daily for adult male and female rats for 21 days. At the end of the stress phase, elevated plus maze (EPM) was used for measuring the stress behavioral effects. Serum corticosterone level was measured by ELISA. BDNF and TrkB gene methylation and protein expression in the HPC were detected using real-time PCR and Western blotting. Chronic stress in the adolescence had more effects on anxiety-like behavior and serum corticosterone concentration in female rats than males. Furthermore, stressed female rats had higher methylation levels and following reduced protein expression of BDNF but not TrkB compared to stressed male rats. These findings suggest that in exposure to a stressor, sex differences in BDNF methylation may be root cause of decreased BDNF levels in females and may underlie susceptibility to pathology development. © 2015, Springer Science+Business Media New York

Axonal transport proteins and depressive like behavior, following Chronic Unpredictable Mild Stress in male rat

Background: A common mood disorder, depression has long been considered a leading cause of disability worldwide. Chronic stress is involved in the development of various psychiatric diseases including major depressive disorder. Stress can induce depressive-like symptoms and initiate neurodegenerative processes in the brain. The neurodegenerative theory of depression holds impaired axonal transport as a negative factor in neural survival. Axonal transport is a critical mechanism for normal neuronal function, playing crucial roles in axon growth, neurotransmitter secretion, normal mitochondrial function and neural survival. Methods and materials: To investigate the effects of stress-induced depression, in the present study, we evaluated behavior by forced swimming test (FST), corticosterone plasma level by ELISA assay, hippocampal mRNA expression of three genes (NGF, kinesin and dynein) via real-time PCR and hippocamp count by Nissl staining in male Wistar rats. Results: Our data demonstrated a significant decrease in the expression of NGF, kinesin and dynein genes in CUMS groups compared to the control group (non-stressed) (p < 0.05). CUMS also caused an elevation in immobility time and corticosterone plasma level in the stressed group compared to the controls (p < 0.01 and p < 0.05, respectively). Conclusion: The results suggested that the possibility of stress-induced depressive behavior associated with hippocampal neurodegeneration process is correlated with a low expression of kinesin and dynein, the two most important proteins in axonal transport. © 2018 Elsevier Inc

The potential impact of tumor suppressor genes on human gametogenesis: a case-control study

PURPOSE: To study the incidence of tumor suppressor gene (TSG) mutations in men and women with impaired gametogenesis. METHODS: Gene association analyses were performed on blood samples in two distinct patient populations: males with idiopathic male infertility and females with unexplained diminished ovarian reserve (DOR). The male study group consisted of men with idiopathic azoospermia, oligozoospermia, asthenozoospermia, or teratozoospermia. Age-matched controls were men with normal semen analyses. The female study group consisted of women with unexplained DOR with anti-Mullerian hormone levels 1.1 ng/mL). RESULTS: Fifty-seven male cases (mean age = 38.4; mean sperm count = 15.7 +/- 12.1; mean motility = 38.2 +/- 24.7) and 37 age-matched controls (mean age = 38.0; mean sperm count = 89.6 +/- 37.5; mean motility = 56.2 +/- 14.3) were compared. Variants observed in CHD5 were found to be enriched in the study group (p = 0.000107). The incidence of CHD5 mutation c.*3198_*3199insT in the 3'UTR (rs538186680) was significantly higher in cases compared to controls (p = 0.0255). 72 DOR cases (mean age = 38.7; mean AMH = 0.5 +/- 0.3; mean FSH = 11.7 +/- 12.5) and 48 age-matched controls (mean age = 37.6; mean AMH = 4.1 +/- 3.0; mean FSH = 7.1 +/- 2.2) were compared. Mutations in CHD5 (c.-140A>C), RB1 (c.1422-18delT, rs70651121), and TP53 (c.376-161A>G, rs75821853) were found at significantly higher frequencies in DOR cases compared to controls (p </= 0.05). In addition, 363 variants detected in the DOR patients were not present in the control group. CONCLUSION: Unexplained impaired gametogenesis in both males and females may be associated with genetic variation in TSGs. TSGs, which play cardinal roles in cell-cycle control, might also be critical for normal spermatogenesis and oogenesis. If validated in larger prospective studies, it is possible that TSGs provide an etiological basis for some patients with impaired gametogenesis