Fire spalling sensitivity of concrete made with recycled concrete aggregates (RCA)

The fire spalling of concrete is a complex phenomenon, which can affect the integrity of the structures during a fire. This thermal instability is associated with a complex coupled chemo-thermo-hydro-mechanical mechanism and it can be influenced by many factors, related to material (e.g. per- meability, porosity and water content), geometry (e.g. shape and size) and environmental parameters (e.g. mechanical load and heating rate). Concrete made with recycled concrete aggregates presents higher porosity, higher water content and different interfaces between aggregates and mortar. All these aspects can lead to a different behaviour under fire exposure, including the spalling risk of these sustainable concretes. The main objective of this paper is to analyse the influence of the use of recycled concrete aggregates on the spalling risk of concrete. In this paper, concrete prisms with different replacement rates of recycled coarse aggregates (0 up to 100%) were exposed to a standard fire curve (ISO 834-1) with a constant uniaxial compression load. After heating, samples surfaces were evaluated by means of digital photogrammetry. Results showed that concrete with RCA is sensitive to explosive spalling. All replacement rates presented higher degree of spalling than concrete made with natural aggregates

Borna Disease Virus Blocks Potentiation of Presynaptic Activity through Inhibition of Protein Kinase C Signaling

Infection by Borna disease virus (BDV) enables the study of the molecular mechanisms whereby a virus can persist in the central nervous system and lead to altered brain function in the absence of overt cytolysis and inflammation. This neurotropic virus infects a wide variety of vertebrates and causes behavioral diseases. The basis of BDV-induced behavioral impairment remains largely unknown. Here, we investigated whether BDV infection of neurons affected synaptic activity, by studying the rate of synaptic vesicle (SV) recycling, a good indicator of synaptic activity. Vesicular cycling was visualized in cultured hippocampal neurons synapses, using an assay based on the uptake of an antibody directed against the luminal domain of synaptotagmin I. BDV infection did not affect elementary presynaptic functioning, such as spontaneous or depolarization-induced vesicular cycling. In contrast, infection of neurons with BDV specifically blocked the enhancement of SV recycling that is observed in response to stimuli-induced synaptic potentiation, suggesting defects in long-term potentiation. Studies of signaling pathways involved in synaptic potentiation revealed that this blockade was due to a reduction of the phosphorylation by protein kinase C (PKC) of proteins that regulate SV recycling, such as myristoylated alanine-rich C kinase substrate (MARCKS) and Munc18–1/nSec1. Moreover, BDV interference with PKC-dependent phosphorylation was identified downstream of PKC activation. We also provide evidence suggesting that the BDV phosphoprotein interferes with PKC-dependent phosphorylation. Altogether, our results reveal a new mechanism by which a virus can cause synaptic dysfunction and contribute to neurobehavioral disorders

Aerobic Fitness Level Affects Cardiovascular and Salivary Alpha Amylase Responses to Acute Psychosocial Stress

BACKGROUND: Good physical fitness seems to help the individual to buffer the potential harmful impact of psychosocial stress on somatic and mental health. The aim of the present study is to investigate the role of physical fitness levels on the autonomic nervous system (ANS; i.e. heart rate and salivary alpha amylase) responses to acute psychosocial stress, while controlling for established factors influencing individual stress reactions. METHODS: The Trier Social Stress Test for Groups (TSST-G) was executed with 302 male recruits during their first week of Swiss Army basic training. Heart rate was measured continuously, and salivary alpha amylase was measured twice, before and after the stress intervention. In the same week, all volunteers participated in a physical fitness test and they responded to questionnaires on lifestyle factors and personal traits. A multiple linear regression analysis was conducted to determine ANS responses to acute psychosocial stress from physical fitness test performances, controlling for personal traits, behavioural factors, and socioeconomic data. RESULTS: Multiple linear regression revealed three variables predicting 15 % of the variance in heart rate response (area under the individual heart rate response curve during TSST-G) and four variables predicting 12 % of the variance in salivary alpha amylase response (salivary alpha amylase level immediately after the TSST-G) to acute psychosocial stress. A strong performance at the progressive endurance run (high maximal oxygen consumption) was a significant predictor of ANS response in both models: low area under the heart rate response curve during TSST-G as well as low salivary alpha amylase level after TSST-G. Further, high muscle power, non-smoking, high extraversion, and low agreeableness were predictors of a favourable ANS response in either one of the two dependent variables. CONCLUSIONS: Good physical fitness, especially good aerobic endurance capacity, is an important protective factor against health-threatening reactions to acute psychosocial stress

Pour une préparation anticipée des futurs enseignants du secondaire à une approche impliquante de la grammaire

Les étudiants qui se destinent à passer les concours de recrutement du secondaire bénéficient à la Sorbonne Nouvelle (et sans doute ailleurs) de cours majoritairement frontaux et transmissifs durant toute leur formation initiale, que ce soit en licence LLCER ou en master MEEF Anglais, 1ère année. Ils sont préparés à passer un concours qui vérifie leurs connaissances en linguistique anglaise et leur capacité à produire des analyses linguistiques, et non leur capacité à l’enseigner dans le secondaire dans le cadre d’une pédagogie actionnelle où l’enseignement de la grammaire reste nécessaire quoique marginal. C’est en 2ème année du Master MEEF anglais, alors que les étudiants, devenus stagiaires, sont déjà en position d’enseignement, que nous leur présentons une méthode pour intégrer le point de grammaire à une séquence actionnelle et leur donnons la possibilité de pratiquer dans le cadre du cours. Nous suggérons ici que l’année de M2 est trop courte pour opérer cette mue nécessaire d’un enseignement frontal et transmissif à une approche pratique et actionnelle. Nous préconisons d’adopter une démarche impliquante tout au long de leur formation universitaire dans la continuité de l’approche actionnelle qu’ils ont connue au lycée. Nous basons notre proposition sur une recherche-action collaborative entamée en 2015 sur des cohortes annuelles de 200 étudiants de deuxième année de licence LLCER anglais (N=600). En nous appuyant sur nos supports de cours, les enquêtes de satisfaction menées auprès des étudiants à l’issue de chaque semestre, et leurs copies d’examens, nous montrons qu’il est possible et souhaitable d’enseigner la grammaire à des spécialistes dans une perspective que nous qualifions d’impliquante à défaut d’être actionnelle. Cette démarche favorise à la fois l’intégration de savoir expert utile à la réussite des concours d’enseignement mais aussi la préparation, par l’exemple, à un enseignement où les apprenants sont placés en situation d’acteurs et non de récepteurs. Students who intend to take the recruitment exams to become secondary school teachers are predominantly exposed to frontal and transmissive courses at Sorbonne Nouvelle university (and probably elsewhere) throughout their initial training, during their BA and their first year of MA. They are trained for a competitive exam that checks their knowledge of English linguistics and their ability to produce linguistic analyses, and not their ability to teach grammar in secondary schools in the context of an action-oriented pedagogy where the teaching of grammar is considered as necessary and yet remains marginal. The students have to wait for the 2nd year of their MA, when they have become interns with teaching responsibilities, to be taught a method to integrate grammar into an action-based class, and to be given the opportunity to practice that method among their fellow students. Our paper suggests that the 2nd year of Master is too short to make this necessary shift from a frontal transmissive teaching to a practical action-oriented approach. We recommend adopting an engaging approach throughout their university training, in the continuity of the action-oriented approach they experienced as pupils in high school. Our contention is based on a collaborative action-research initiated in 2015 and targeted at annual cohorts of 200 undergraduate second-year English Majors (N = 600). Our data is made up of the course material, satisfaction surveys conducted at the end of each semester, and the students’ exam papers. We show that it is both possible and desirable to teach grammar to English Majors using an engaging approach – as we cannot describe our approach as fully action-based. It promotes the learning of expert knowledge that will help the students pass their teaching exam. It also prepares them to teach in classrooms where pupils are meant to be active learners

Stage-Wise Learning of Reaching Using Little Prior Knowledge

In some manipulation robotics environments, because of the difficulty of precisely modeling dynamics and computing features which describe well the variety of scene appearances, hand-programming a robot behavior is often intractable. Deep reinforcement learning methods partially alleviate this problem in that they can dispense with hand-crafted features for the state representation and do not need pre-computed dynamics. However, they often use prior information in the task definition in the form of shaping rewards which guide the robot toward goal state areas but require engineering or human supervision and can lead to sub-optimal behavior. In this work we consider a complex robot reaching task with a large range of initial object positions and initial arm positions and propose a new learning approach with minimal supervision. Inspired by developmental robotics, our method consists of a weakly-supervised stage-wise procedure of three tasks. First, the robot learns to fixate the object with a 2-camera system. Second, it learns hand-eye coordination by learning to fixate its end-effector. Third, using the knowledge acquired in the previous steps, it learns to reach the object at different positions and from a large set of initial robot joint angles. Experiments in a simulated environment show that our stage-wise framework yields similar reaching performances, compared with a supervised setting without using kinematic models, hand-crafted features, calibration parameters or supervised visual modules

Quantification of the animal tuberculosis multi-host community offers insights for control

Animal tuberculosis (TB) is a multi-host zoonotic disease whose prevalence in cattle herds in Europe has been increasing, despite a huge investment in eradication. The composition of the host community is a fundamental driver of pathogen transmission, and yet this has not been formally quantified for animal TB in Europe. We quantified multi-host communities of animal TB, using stochastic models to estimate the number of infected domestic and wild hosts in three regions: officially TB-free Central–Western Europe, and two largely TB-endemic regions, the Iberian Peninsula and Britain and Ireland. We show that the estimated number of infected animals in the three regions was 290,059–1,605,612 and the numbers of infected non-bovine domestic and wild hosts always exceeded those of infected cattle, with ratios ranging from 3.3 (1.3–19.6):1 in Britain and Ireland to 84.3 (20.5–864):1 in the Iberian Peninsula. Our results illustrate for the first time the extent to which animal TB systems in some regions of Europe are dominated by non-bovine domestic and wild species. These findings highlight the need to adapt current strategies for effective future control of the disease.This research was funded by MINECO and EU-FEDER WildDriver grant CGL2017-89866; NS was funded by FCT—Fundação para a Ciência e a Tecnologia grant SFRH/BPD/116596/2016

Using remote sensing to map larval and adult populations of Anopheles hyrcanus (Diptera: Culicidae) a potential malaria vector in Southern France

Although malaria disappeared from southern France more than 60 years ago, suspicions of recent autochthonous transmission in the French Mediterranean coast support the idea that the area could still be subject to malaria transmission. The main potential vector of malaria in the Camargue area, the largest river delta in southern France, is the mosquito Anopheles hyrcanus (Diptera: Culicidae). In the context of recent climatic and landscape changes, the evaluation of the risk of emergence or re-emergence of such a major disease is of great importance in Europe. When assessing the risk of emergence of vector-borne diseases, it is crucial to be able to characterize the arthropod vector's spatial distribution. Given that remote sensing techniques can describe some of the environmental parameters which drive this distribution, satellite imagery or aerial photographs could be used for vector mapping.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

Quelle place pour la recherche dans l'apprentissage des métiers de la communication ?

On the basis of a study conducted in collaboration with Formasup in the Hauts-de-France region, the aim is to observe what "research does to learning" and, conversely, what "learning does to research" in the diversity of educational projects in the field of information and communication sciences. In short, it is a question of appreciating the forms and the added value of the research in the devices of training to the communication by way of learning.Sur la base d’une étude conduite en collaboration avec le CFA Formasup en région Hauts-de-France, il s’agit d’observer ce que « la recherche fait à l’apprentissage » et, réciproquement, ce que « l’apprentissage fait à la recherche » dans la diversité des projets pédagogiques en Sciences de l’Information et de la Communication et des besoins en recherche exprimés par les structures d’accueil. En bref, il s’agit d’apprécier les formes et la valeur ajoutée de la recherche dans les dispositifs de formation à la communication par voie d’apprentissage

Hyperglycaemia and apoptosis of microglial cells in human septic shock

International audienceIntroductionThe effect of hyperglycaemia on the brain cells of septic shock patients is unknown. The objective of this study was to evaluate the relationship between hyperglycaemia and apoptosis in the brains of septic shock patients.MethodsIn a prospective study of 17 patients who died from septic shock, hippocampal tissue was assessed for neuronal ischaemia, neuronal and microglial apoptosis, neuronal Glucose Transporter (GLUT) 4, endothelial inducible Nitric Oxide Synthase (iNOS), microglial GLUT5 expression, microglial and astrocyte activation. Blood glucose (BG) was recorded five times a day from ICU admission to death. Hyperglycaemia was defined as a BG 200 mg/dL g/l and the area under the BG curve (AUBGC) > 2 g/l was assessed.ResultsMedian BG over ICU stay was 2.2 g/l. Neuronal apoptosis was correlated with endothelial iNOS expression (rho = 0.68, P = 0.04), while microglial apoptosis was associated with AUBGC > 2 g/l (rho = 0.70; P = 0.002). Neuronal and microglial apoptosis correlated with each other (rho = 0.69, P = 0.006), but neither correlated with the duration of septic shock, nor with GLUT4 and 5 expression. Neuronal apoptosis and ischaemia tended to correlate with duration of hypotension.ConclusionsIn patients with septic shock, neuronal apoptosis is rather associated with iNOS expression and microglial apoptosis with hyperglycaemia, possibly because GLUT5 is not downregulated. These data provide a mechanistic basis for understanding the neuroprotective effects of glycemic control