Closed-loop separation control over a sharp edge ramp using Genetic Programming

We experimentally perform open and closed-loop control of a separating turbulent boundary layer downstream from a sharp edge ramp. The turbulent boundary layer just above the separation point has a Reynolds number $Re_{\theta}\approx 3\,500$ based on momentum thickness. The goal of the control is to mitigate separation and early re-attachment. The forcing employs a spanwise array of active vortex generators. The flow state is monitored with skin-friction sensors downstream of the actuators. The feedback control law is obtained using model-free genetic programming control (GPC) (Gautier et al. 2015). The resulting flow is assessed using the momentum coefficient, pressure distribution and skin friction over the ramp and stereo PIV. The PIV yields vector field statistics, e.g. shear layer growth, the backflow area and vortex region. GPC is benchmarked against the best periodic forcing. While open-loop control achieves separation reduction by locking-on the shedding mode, GPC gives rise to similar benefits by accelerating the shear layer growth. Moreover, GPC uses less actuation energy.Comment: 24 pages, 24 figures, submitted to Experiments in Fluid

Changes in liver mitochondrial plasticity induced by brain tumor

BACKGROUND: Accumulating data suggest that liver is a major target organ of systemic effects observed in the presence of a cancer. In this study, we investigated the consequences of the presence of chemically induced brain tumors in rats on biophysical parameters accounting for the dynamics of water in liver mitochondria. METHODS: Tumors of the central nervous system were induced by intraveinous administration of ethylnitrosourea (ENU) to pregnant females on the 19th day of gestation. The mitochondrial crude fraction was isolated from the liver of each animal and the dynamic parameters of total water and its macromolecule-associated fraction (structured water, H(2)Ost) were calculated from Nuclear Magnetic Resonance (NMR) measurements. RESULTS: The presence of a malignant brain tumor induced a loss of water structural order that implicated changes in the physical properties of the hydration shells of liver mitochondria macromolecules. This feature was linked to an increase in the membrane cholesterol content, a way to limit water penetration into the bilayer and then to reduce membrane permeability. As expected, these alterations in mitochondrial plasticity affected ionic exchanges and led to abnormal features of mitochondrial biogenesis and caspase activation. CONCLUSION: This study enlightens the sensitivity of the structured water phase in the liver mitochondria machinery to external conditions such as tumor development at a distant site. The profound metabolic and functional changes led to abnormal features of ion transport, mitochondrial biogenesis and caspase activation

Disruption of Dnmt1/PCNA/UHRF1 Interactions Promotes Tumorigenesis from Human and Mice Glial Cells

Global DNA hypomethylation is a hallmark of cancer cells, but its molecular mechanisms have not been elucidated. Here, we show that the disruption of Dnmt1/PCNA/UHRF1 interactions promotes a global DNA hypomethylation in human gliomas. We then demonstrate that the Dnmt1 phosphorylations by Akt and/or PKC abrogate the interactions of Dnmt1 with PCNA and UHRF1 in cellular and acelluar studies including mass spectrometric analyses and the use of primary cultured patient-derived glioma. By using methylated DNA immunoprecipitation, methylation and CGH arrays, we show that global DNA hypomethylation is associated with genes hypomethylation, hypomethylation of DNA repeat element and chromosomal instability. Our results reveal that the disruption of Dnmt1/PCNA/UHRF1 interactions acts as an oncogenic event and that one of its signatures (i.e. the low level of mMTase activity) is a molecular biomarker associated with a poor prognosis in GBM patients. We identify the genetic and epigenetic alterations which collectively promote the acquisition of tumor/glioma traits by human astrocytes and glial progenitor cells as that promoting high proliferation and apoptosis evasion

Applying an immersive tutorial in virtual reality to learning a new technique

International audienc

Rev Med Interne

We aimed to evaluate the impact of an immersive simulation session on the experience of the beginning of residency. The interventional group consisted of newly recruited residents in 2019, who participated in the workshop presenting four emergency scenarios frequently encountered during night shifts; the control group comprised residents who had begun their internship in 2018, without having participated in the simulation workshop. The level of psychological stress and self-confidence were self-estimated in the simulation group before and immediately after the workshop. During the second semester of residency, stress, self-efficacy and anxiety were evaluated in both groups with the Perceived Stress Scale (PSS), General Self-efficacy Scale (GSES), and Generalized Anxiety Disorder-7 (GAD-7) scale. In the second semester 2020, the PSS, GSES and GAD-7 were 20.71±8.15 and 22.44±5.68 (P=0.40); 26.88±6.30 and 27.11±3.95 (P=0.87); 6.94±5.25 and 8.89±4.78 (P=0.22) for the simulation (n=17, 89.5% of participation) and control (n=9, 75%) groups, respectively. In the simulation group, the level of self-confidence had significantly improved from 1.82±0.95 before the session to 2.29±1.16 after the session (P=0.05). Interestingly, this improvement in self-confidence was significantly correlated with GAD-7 (P=0.014) and PSS (P=0.05), and tended to be correlated with GSES (P=0.09). Our study showed a significant improvement in self-confidence between before and after the simulation session. Residents who experienced an improvement in self-confidence saw their stress and anxiety levels decrease during the second semester reevaluation, in favor of a prolonged benefit from the session

Fast analysis of beta-ecdysone in Brazilian ginseng (Pfaffia glomerata) extracts by high-performance liquid chromatography using a fused-core column

The recent development of fused-core technology in HPLC columns is enabling faster and highly efficient separations. This technology was evaluated for the development of a fast analysis method for beta-ecdysone in extracts of Pfaffia glomerata. A step-by-step strategy was used to optimize temperature (30-55 degrees C), flow rate (1.0-2.0 mL min(-1)), mobile phase composition (mixtures of water and methanol or acetonitrile) and equilibration time (1-5 min). A gradient method has been developed using two solvents: 0.1% acetic acid in water and 0.1% acetic acid in acetonitrile. Optimized conditions provided a method for the separation of beta-ecdysone in approximately 2 min with a total analysis time (sample-to-sample) of 9 min, including the return to initial conditions and the re-equilibration of the column. Evaluation of chromatographic performance revealed excellent intraday and interday reproducibility (>99.5%), resolution (2.78), selectivity (1.13), and peak symmetry (1.09) while presenting low limits of detection (0.20 mg L-1) and quantitation (0.67 mg L-1). The robustness of the method has also been calculated according to the concentration/dilution of the sample. Several sample solvents were evaluated and the best chromatographic results were obtained using 80% methanol in water. Finally, the developed method was validated with different extracts of Pfaffia glomerata samples6824522459CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP470916/2012-5; 560914/2010-5; 140282/2013-0; 151165/2010-62012/10685-8; 2013/04304-4; 2013/15049-

Premières identifications d’un profil traumatique chez des patients hospitalisés en psychiatrie en Martinique

La population hospitalisée en psychiatrie apparaît davantage exposée à des événements traumatiques que la population française en général, avec plus particulièrement des agressions à caractère sexuel. Notre objectif principal est de décrire la population hospitalisée en psychiatrie et en particulier l’histoire traumatique des patients, les comorbidités associées (psychiatriques et addictologiques) ainsi que le niveau socioéconomique. Cette étude descriptive, transversale et rétrospective a été réalisée au Centre de crise du Centre Hospitalo-Universitaire de Martinique de février à juillet 2013. Un questionnaire socioéconomique, le Mini International Neuropsychiatric Interview 5.0, le Trauma History Questionnaire et le questionnaire Impact Events Scale-Revised (IES-R) ont été réalisés de façon aléatoire auprès de 49 des 143 patients admis sur cette période (soit 34,3 %). Dans notre échantillon, une moyenne de 6,5 types différents d’événements traumatiques a été établie (écart-type = 4,2) : 38,8 % des patients rapportent un traumatisme à la suite d’une catastrophe naturelle, et 38,8 % déclarent au moins une agression sexuelle. Parmi les 25 patients souffrant de syndrome de stress post-traumatique, 66,7 % ont subi une agression sexuelle dans l’enfance, avant l’âge de 10 ans (P = 0,01), et dans l’adolescence, entre 10 et 18 ans (P = 0,01). Ces résultats soulignent l’importance d’interroger systématiquement le profil traumatique, c’est-à-dire l’association entre les événements traumatiques et leur retentissement clinique.The population hospitalised in psychiatry seems more exposed to traumatic events than the French general population, with particularly more sexual aggressions. The aim of this study is to describe the population hospitalised in psychiatry and more precisely the traumatic history of these patients, their comorbidities (mental diseases and addictions), and socio economical level. This descriptive, cross sectional and retrospective study took place in the Crisis Center in the University Hospital in Martinique (French West Indies), from February to July 2013. A socio-demographic information, the Mini International Neuropsychiatric Interview 5.0, the Trauma History Questionnaire and the Impact Events Scale-Revised were realised with 49 of the 143 patients admitted during this period (34.3%). In this population, we found a mean of 6.5 (standart-deviation=4.2) different types of traumatic event, with 38.8% patients reporting a natural disaster, and 38.8% declaring at least one sexual aggression. In the 25 patients suffering from post-traumatic stress disorder, 66.7% underwent a sexual aggression, significatively during childhood (before 10 years old, P=0.01), and during adolescence (between 10 to 18 years old, P=0.01). These results underline the importance of a systematic screening of the traumatic profile: the characteristics of the traumatic events and its clinical impact