Transformation kinetics and microstructures of Ti17 titanium alloy during continuous cooling

International audienceWe have investigated the microstructure evolutions in the Ti17 near Click to view the MathML source titanium alloy during heat treatments. The phase transformation has first been studied experimentally by combining X-ray diffraction analysis, electrical resistivity and microscopy observations. From a series of isothermal treatments, a IT diagram has been determined, which takes into account the different morphologies. Then, a Johnson–Mehl–Avrami–Kolmogorov (JMAK) model has been successfully used to describe the phase transformation kinetics during either isothermal or cooling treatments. Finally, the coupling of the JMAK model to the finite element software ZeBuLoN allowed us to investigate the evolution of the spatial distribution of the different morphologies during the cooling of an aircraft engine shaft disk after forging

A new energy detector of micro-emboli using a time-varying threshold

International audienceDetection of small emboli, precursors of Cerebrovascular Accidents, is a worldwide concern since CVAs represent the second cause of mortality in the world. Computerized analysis of Transcranial Doppler signals can aid early detection of circulating emboli and micro-emboli. Commercially used systems of automatic emboli detection rely on standard short time Fourier transform techniques in which detection is based on constant thresholds. These standard algorithms do not offer robust detections and are incapable of detecting the smallest micro-emboli. To enhance this detection, we propose in this study optimized techniques based on novel methods of threshold application. By implementing our new time-varying threshold of detection, we were able to decrease the probability of non-detection and the probability of false alarm by around half the values obtained by standard techniques. Moreover, our new techniques were clearly efficient in exploiting the transient-like embolic signals and hence make detection of micro-emboli easier and more evident. This was proved by enhancing important parameters of which are the embolus to blood ratio and the peak to threshold ratio. Applied on our set of recorded signals, the new detectors allowed obtaining embolus to blood ratios twice greater than the embolus to blood ratios achieved by standard techniques and a sufficient increase in peak to threshold ratios

A Micro-Embolic Energy Detector based on Sub-band Decomposition

International audienceCerebrovascular Accidents can be caused by cerebral emboli blocking brain blood vessels. Analysis of transcranial Doppler signals practically aids the detection of emboli. Signal processing methods have been proposed for emboli detection. In this study, we introduce a new micro-embolic energy detector composed of N detectors associated to N Doppler frequency sub-bands. To test our detectors, we propose a training phase during which we adjust the optimal number of sub-bands and detection thresholds and a testing phase through which we measure performances. Using real signals, we show that in terms of the number of sub-bands, 4 sub-bands provide the highest detection rate and lowest false alarm. Moreover, compared to standard detectors, the 4 sub-band energy detector reduces the false alarm rate from 44% to 36%, increases the detection rate from 66% to 79% and augments the Embolus to Blood Ratio from 24 dB to 40 dB. This new energy detector permits detecting smallest micro-emboli, precursors of coming large emboli with high stroke risks

Personalised pathway analysis reveals association between DNA repair pathway dysregulation and chromosomal instability in sporadic breast cancer

The Homologous Recombination (HR) pathway is crucial for the repair of DNA double-strand breaks (DSBs) generated during DNA replication. Defects in HR repair have been linked to the initiation and development of a wide variety of human malignancies, and exploited in chemical, radiological and targeted therapies. In this study, we performed a personalised pathway analysis independently for four large sporadic breast cancer cohorts to investigate the status of HR pathway dysregulation in individual sporadic breast tumours, its association with HR repair deficiency and its impact on tumour characteristics. Specifically, we first manually curated a list of HR genes according to our recent review on this pathway (Liu et al., 2014), and then applied a personalised pathway analysis method named Pathifier (Drier et al., 2013) on the expression levels of the curated genes to obtain an HR score quantifying HR pathway dysregulation in individual tumours. Based on the score, we observed a great diversity in HR dysregulation between and within gene expression-based breast cancer subtypes, and by using two published HR-defect signatures, we found HR pathway dysregulation reflects HR repair deficiency. Furthermore, we identified a novel association between HR pathway dysregulation and chromosomal instability (CIN) in sporadic breast cancer. Although GIN has long been considered as a hallmark of most solid tumours, with recent extensive studies highlighting its importance in tumour evolution and drug resistance, the molecular basis of CIN in sporadic cancers remains poorly understood. Our results imply that HR pathway dysregulation might contribute to CIN in sporadic breast cancer. (C) 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved

Spatial-temporal pattern of malaria in Burkina Faso from 2013 to 2020.

Despite the implementation of different strategies to fight against malaria in Burkina Faso since 2005, it remains today the leading cause of hospitalization and death. Adapting interventions to the spatial and temporal distribution of malaria could help to reduce this burden. This study aims to determine the structure and stability of malaria hotspots in Burkina Faso, with the objective of adapting interventions at small geographical scales. Data on malaria cases from 2013 to 2020 were acquired at municipalities level. Municipality-wise malaria endemicity levels were mapped through geographical information system (GIS) tools. Spatial statistical analysis using Kulldoff sweeps were carried out to identify malaria hotspots. Then we mapped the monthly malaria risk. Malaria is endemic in all the municipalities of Burkina Faso. However, two stable main spatial clusters (South-Western and Eastern part of the country) are emerging with seasonal reinforcement. Interventions targeting the identified clusters could significantly reduce the incidence of malaria in Burkina Faso. This also prompts for further studies to identify the local determinants of this high transmission for the future success of malaria control

Effects of malnutrition on mortality in oldest-old inpatients with COVID-19 in the GERIA-COVID cohort: Additional findings from the AgeBru cohort.

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Genome analysis of the necrotrophic fungal pathogens Sclerotinia sclerotiorum and Botrytis cinerea

Sclerotinia sclerotiorum and Botrytis cinerea are closely related necrotrophic plant pathogenic fungi notable for their wide host ranges and environmental persistence. These attributes have made these species models for understanding the complexity of necrotrophic, broad host-range pathogenicity. Despite their similarities, the two species differ in mating behaviour and the ability to produce asexual spores. We have sequenced the genomes of one strain of S. sclerotiorum and two strains of B. cinerea. The comparative analysis of these genomes relative to one another and to other sequenced fungal genomes is provided here. Their 38–39 Mb genomes include 11,860–14,270 predicted genes, which share 83% amino acid identity on average between the two species. We have mapped the S. sclerotiorum assembly to 16 chromosomes and found large-scale co-linearity with the B. cinerea genomes. Seven percent of the S. sclerotiorum genome comprises transposable elements compared t

Kepler-21b: A 1.6REarth Planet Transiting the Bright Oscillating F Subgiant Star HD 179070

We present Kepler observations of the bright (V=8.3), oscillating star HD 179070. The observations show transit-like events which reveal that the star is orbited every 2.8 days by a small, 1.6 R_Earth object. Seismic studies of HD 179070 using short cadence Kepler observations show that HD 179070 has a frequencypower spectrum consistent with solar-like oscillations that are acoustic p-modes. Asteroseismic analysis provides robust values for the mass and radius of HD 179070, 1.34{\pm}0.06 M{\circ} and 1.86{\pm}0.04 R{\circ} respectively, as well as yielding an age of 2.84{\pm}0.34 Gyr for this F5 subgiant. Together with ground-based follow-up observations, analysis of the Kepler light curves and image data, and blend scenario models, we conservatively show at the >99.7% confidence level (3{\sigma}) that the transit event is caused by a 1.64{\pm}0.04 R_Earth exoplanet in a 2.785755{\pm}0.000032 day orbit. The exoplanet is only 0.04 AU away from the star and our spectroscopic observations provide an upper limit to its mass of ~10 M_Earth (2-{\sigma}). HD 179070 is the brightest exoplanet host star yet discovered by Kepler.Comment: Accepted to Ap