Pour une nouvelle vitrine de la francophonie au Burkina Faso

C\u27est une course folle vers la modernité. En dix mois, l\u27Institut français de Ouagadougou a transformé sa bibliothèque vieillotte en une médiathèque performante. Bibliothécaires de France et d\u27Afrique en sont les acteurs. Avec une enveloppe de 215 000 , ils restructurent l\u27espace et l\u27organisation interne de l\u27établissement. Récit de cette coopération franco-africaine

Anatomical Connectivity Influences both Intra- and Inter-Brain Synchronizations

Recent development in diffusion spectrum brain imaging combined to functional simulation has the potential to further our understanding of how structure and dynamics are intertwined in the human brain. At the intra-individual scale, neurocomputational models have already started to uncover how the human connectome constrains the coordination of brain activity across distributed brain regions. In parallel, at the inter-individual scale, nascent social neuroscience provides a new dynamical vista of the coupling between two embodied cognitive agents. Using EEG hyperscanning to record simultaneously the brain activities of subjects during their ongoing interaction, we have previously demonstrated that behavioral synchrony correlates with the emergence of inter-brain synchronization. However, the functional meaning of such synchronization remains to be specified. Here, we use a biophysical model to quantify to what extent inter-brain synchronizations are related to the anatomical and functional similarity of the two brains in interaction. Pairs of interacting brains were numerically simulated and compared to real data. Results show a potential dynamical property of the human connectome to facilitate inter-individual synchronizations and thus may partly account for our propensity to generate dynamical couplings with others

Study of transformations and microstructural modification in Ti-LCB and T-555 alloys using Differential Scanning Calorimetry

peer reviewedThe aerospace industry is the single largest market for titanium products primarily due to the exceptional strength to weight ratio, elevated temperature performance and corrosion resistance. Titanium applications are most significant in jet engine and airframe components that are subject to high temperatures. The studied Ti-LCB and Ti-555 titanium alloys must present good properties to fatigue damage as they are located in a low-pressure compressor. In order to avoid this damage, an optimized alloy microstructure is required. In our case, the optimal microstructure would be a beta matrix in which small alpha particles are uniformly distributed, obtained after a combination of thermomechanical and thermal treatments. The understanding of the mechanisms ruling the microstructure evolution is achieved through the study of phase transformations versus temperature. During heating, the ωath phase is transformed into the ωiso phase, allowing itself the appearance of the α phase. Then this α phase is transformed progressively into the β phase, and the structure becomes totally β when the transus temperature is reached. Therefore, a thermal analysis tool such as DSC (Differential Scanning Calorimetry) was used in order to characterise the phase transformations of the material during imposed controlled temperature programs

Inter-Brain Synchronization during Social Interaction

During social interaction, both participants are continuously active, each modifying their own actions in response to the continuously changing actions of the partner. This continuous mutual adaptation results in interactional synchrony to which both members contribute. Freely exchanging the role of imitator and model is a well-framed example of interactional synchrony resulting from a mutual behavioral negotiation. How the participants' brain activity underlies this process is currently a question that hyperscanning recordings allow us to explore. In particular, it remains largely unknown to what extent oscillatory synchronization could emerge between two brains during social interaction. To explore this issue, 18 participants paired as 9 dyads were recorded with dual-video and dual-EEG setups while they were engaged in spontaneous imitation of hand movements. We measured interactional synchrony and the turn-taking between model and imitator. We discovered by the use of nonlinear techniques that states of interactional synchrony correlate with the emergence of an interbrain synchronizing network in the alpha-mu band between the right centroparietal regions. These regions have been suggested to play a pivotal role in social interaction. Here, they acted symmetrically as key functional hubs in the interindividual brainweb. Additionally, neural synchronization became asymmetrical in the higher frequency bands possibly reflecting a top-down modulation of the roles of model and imitator in the ongoing interaction

O desempenho da medida da translucência nucal na predição do desfecho gestacional

Purpose: nuchal translucency (NT) is the sonographic appearance of the fluid accumulation in the posterior cervical region of the fetus, in the first trimester of pregnancy. It is used as an excellent method of screening for aneuploidy. In this study, we evaluate the association of NT measurement in exams performed at the institution with the occurrence of pregnancy outcomes. Objectives: To characterize the studied sample according with the maternal age, paternal age, gestational age and head length, buttocks of the fetus at the time of the examination. Examine the association between NT thickness measurement with the spontaneous termination of pregnancy; with the presence of chromosomal changes and malformation. Methods: A retrospective, descriptive and transversal study. 687 cases of singleton pregnancies were included, who performed ultrasonography with NT measure, with known outcome of pregnancy. Pregnancy outcomes were: miscarriage, fetal death, chromosomal abnormalitiesanmalformation. ROC (Receiver Operator Characteristic) curve was constructed to determine the performance of the test, define the value for the one that was verified the test sensitivity with false positive rate of 5% and performed logistic regression analysis for each of the possible outcomes studied. Results: 664 cases were normal and 23 showed an outcome.The gestational age ranged between 11 and 14.57 weeks and the CRL ranged from 45.2mm to 83.8mm. The mothers age ranged from 12 to 47 years. The paternal age ranged from 15 to 65 years. The NT thickness distribution showed an average of 1.617. In our sample, from the established cutoff point of 2.44 mm, it was verified that the NT measurement was excellent predictor of chromosomal alterations with AUC of 0.9961, and a sensitivity of 100% with a false positive rate of 5%. Abortions had low values ofNT, which was confirmed by the AUC 0.54 and sensitivity of 0%. Stillbirth sensitivity of 20%, with AUC of 0.7254.Regarding the association of NT thickness in the presence of malformation, it was found a good discriminatory ability of the test (AUC - 0.070), with a sensitivity of 57% for the cutoff of 2.4mm and an odds ratio of 6.017 in the sample. Conclusions: The measurement of NT thickness in the studied sample, had good association with the occurrence of fetal death and not associated with the occurrence of abortion. The association with the presence of chromosomal and morphological changes was excellent.Introdução: Translucência nucal (TN) é a aparência ultrassonográfica do acúmulo de fluido na região cervical posterior do feto, no 1otrimestre da gravidez. É utilizado como excelente método de rastreio para aneuploidias. Neste trabalho avaliaremos a associação da medida da TN, nos exames realizados na instituição com a ocorrência dos desfechos estacionais. Objetivos: Caracterizar a amostra estudada quanto à idade materna, idade paterna, idade gestacional e comprimento cabeça nádega do feto no momento do exame. Verificar a associação da medida da espessura da TN com a interrupção espontânea da gestação; com a presença de alterações cromossômicas e com a presença de malformações. Métodos: Estudo retrospectivo, transversal e descritivo. Foram incluídos 687 casos de gestações únicas, que realizaram ultrassonografia (USG)com a medida da TN, com desfecho conhecido da gestação. Os desfechos foram: aborto espontâneo, óbito fetal, alterações cromossômicas e malformações. Foi construída curva ROC (receiver operator characteristic) para determinar o desempenho do teste, definir o valor para a qual foi verificada a sensibilidade do teste com taxa de falso positivo de 5%e realizada análise de regressão logística para cada um dos possíveis desfechos estudados. Resultados: 664 casos foram considerados normais e 23 apresentaram algum desfecho. A idade gestacional variou entre 11 e 14,57 semanas e o CCN variou de 45,2mm a 83,8mm. A idade das gestantes variou de 12 a 47 anos. A idade paterna variou de 15 a 65 anos. A distribuição da espessura da TN apresentou média de 1,617.Na amostra estudada a partir do ponto de corte estabelecido de 2,4mm, verificou-se que a medida da TN foi excelente preditor de alterações cromossômicas com AUC de 0,9961, além de sensibilidade de 100% com taxa de falso positivo de 5%. Aborto apresentaram valores baixos de TN o que foi confirmado pela AUC de 0,54 e sensibilidade de 0%. Óbito fetal sensibilidade de 20%, com AUC de 0,7254. E quanto à associação da espessura da TN com a presença de malformações foi verificado boa habilidade discriminatória do exame (AUC – 0,070) com sensibilidade de 57% para o ponto de corte de 2,4mm e Odds ratio de 6,017 na amostra estudada. Conclusões: A medida da espessura da TN, na amostra estudada, teve boa associação com a ocorrência de óbito fetal e não apresentou associação com a ocorrência de abortamento. A associação com a presença de alterações cromossômicas e morfológicas foi excelente

Does the brain know who is at the origin of what in an imitative interaction?

Brain correlates of the sense of agency have recently received increased attention. However, the explorations remain largely restricted to the study of brains in isolation. The prototypical paradigm used so far consists of manipulating visual perception of own action while asking the subject to draw a distinction between self- versus externally caused action. However, the recent definition of agency as a multifactorial phenomenon combining bottom-up and top-down processes suggests the exploration of more complex situations. Notably there is a need of accounting for the dynamics of agency in a two-body context where we often experience the double faceted question of who is at the origin of what in an ongoing interaction. In a dyadic context of role switching indeed, each partner can feel body ownership, share a sense of agency and altogether alternate an ascription of the primacy of action to self and to other. To explore the brain correlates of these different aspects of agency, we recorded with dual EEG and video set-ups 22 subjects interacting via spontaneous versus induced imitation (II) of hand movements. The differences between the two conditions lie in the fact that the roles are either externally attributed (induced condition) or result from a negotiation between subjects (spontaneous condition). Results demonstrate dissociations between self- and other-ascription of action primacy in delta, alpha and beta frequency bands during the condition of II. By contrast a similar increase in the low gamma frequency band (38–47 Hz) was observed over the centro-parietal regions for the two roles in spontaneous imitation (SI). Taken together, the results highlight the different brain correlates of agency at play during live interactions

A short-term divergent selection for resistance to Teladorsagia circumcincta in Romanov sheep using natural or artificial challenge

This experiment was conducted to assess the efficiency of selection on the basis of response to artificial challenges in order to breed sheep resistant to natural infection. A short-term divergent selection process was designed to estimate the genetic parameters of these two traits. Two flocks, including 100 Romanov ram lambs each, were challenged in 1990 when they were 6 months old. One flock received three artificial infections with 20 000 third-stage Teladorsagia circumcincta larvae, at intervals of 7 weeks. Faecal egg counts (FEC) were performed on Days 22, 25 and 28 post infection (p.i.) and the animals were drenched on Day 28 p.i. The other flock was grazed for 5 months on a pasture contaminated with the same species. Faecal samples were taken from the lambs at similar ages. About 5 rams with the lowest FEC and 5 with the highest FEC were selected in each flock and mated with unselected ewes. Their offspring (200 animals) were challenged in 1992, half in the same way as their sires, and the other half by the other method. Because of a drought in the summer of 1990, it was necessary to repeat part of the experiment, and in 1992 the 5 and 8 rams with the lowest and highest FEC, respectively, were selected from the offspring challenged on the pasture in 1992 and were mated with unselected ewes. Their progeny (about 80 animals) were challenged in 1994, half by natural infection, half by artificial infection. The mean FEC of the flock increased from the first to the third artificial infection. The natural infection was highly variable in different years, reflecting the difficulty of assessing resistance using this mode of challenge. Genetic parameters were estimated using animal models and REML solutions. The repeatabilities of the FEC following artificial and natural infection were 0.49 and 0.70 respectively within a period of one week, and 0.22 and 0.41 respectively for periods separated by intervals of 7 weeks; the heritabilities of the single egg count were 0.22 and 0.38 respectively. The genetic correlation was 0.87: the FEC recorded under natural or artificial infection appear to depend on the same genetic potential