Time Transfer functions as a way to validate light propagation solutions for space astrometry

Given the extreme accuracy of modern space astrometry, a precise relativistic modeling of observations is required. Concerning light propagation, the standard procedure is the solution of the null-geodesic equations. However, another approach based on the Time Transfer Functions (TTF) has demonstrated its capability to give access to key quantities such as the time of flight of a light signal between two point-events and the tangent vector to its null-geodesic in a weak gravitational field using an integral-based method. The availability of several models, formulated in different and independent ways, must not be considered like an oversized relativistic toolbox. Quite the contrary, they are needed as validation to put future experimental results on solid ground. The objective of this work is then twofold. First, we build the time of flight and tangent vectors in a closed form within the TTF formalism giving the case of a time dependent metric. Second, we show how to use this new approach to obtain a comparison of the TTF with two existing modelings, namely GREM and RAMOD. In this way, we evidentiate the mutual consistency of the three models, opening the basis for further links between all the approaches, which is mandatory for the interpretation of future space missions data. This will be illustrated through two recognized cases: a static gravitational field and a system of monopoles in uniform motion.Comment: 16 pages, submitted to CQ

Leptin Reverts Pro-Apoptotic and Antiproliferative Effects of α-Linolenic Acids in BCR-ABL Positive Leukemic Cells: Involvement of PI3K Pathway

It is suspected that bone marrow (BM) microenvironmental factors may influence the evolution of chronic myeloid leukaemia (CML). In this study, we postulated that adipocytes and lipids could be involved in the progression of CML. To test this hypothesis, adipocytes were co-cultured with two BCR-ABL positive cell lines (PCMDS and K562). T cell (Jurkat) and stroma cell (HS-5) lines were used as controls. In the second set of experiments, leukemic cell lines were treated with stearic, oleic, linoleic or α-linolenic acids in presence or absence of leptin. Survival, proliferation, leptin production, OB-R isoforms (OB-Ra and OB-Rb), phosphoinositide 3-kinase (PI3k) and BCL-2 expression have been tested after 24h, 48h and 72h of treatment. Our results showed that adipocytes induced a decrease of CML proliferation and an increase in lipid accumulation in leukemic cells. In addition, CML cell lines induced adipocytes cell death. Chromatography analysis showed that BM microenvironment cells were full of saturated (SFA) and monounsaturated (MUFA) fatty acids, fatty acids that protect tumor cells against external agents. Stearic acid increased Bcl-2 expression in PCMDS, whereas oleic and linoleic acids had no effects. In contrast, α-linolenic acid decreased the proliferation and the survival of CML cell lines as well as BCL-2 and OB-R expression. The effect of α-linolenic acids seemed to be due to PI3K pathway and Bcl-2 inhibition. Leptin production was detected in the co-culture medium. In the presence of leptin, the effect of α-linolenic acid on proliferation, survival, OB-R and BCl-2 expression was reduced

When a Digital Learning System Cannot Replace Face-to-Face Teaching, as Demonstrated by Postpandemic Practical Work at the Postsecondary Level

peer reviewedCette étude mesure l’efficacité d’un dispositif de travaux pratiques sous forme de classe inversée, dans un contexte postpandémique. Elle fait ressortir, lorsqu’un dispositif numérique à distance de substitution est mis en place, l’importance du maintien d’un enseignement en présentiel : i) le présentiel permet de pallier les inégalités observées lors d’un travail numérique à distance; ii) il permet un encadrement rapproché; iii) il permet de développer davantage les acquis de type appliqué. De plus, elle démontre que la partie présentielle d’un apprentissage hybride permet bien plus que le simple maintien d’un contact humain.This study measures the effectiveness of practical work organized as a flipped-learning system in the postpandemic context. It highlights the importance of maintaining in-person learning when a distance learning is implemented, for the following reasons: i) in-person learning can compensate for the inequalities observed with distance learning; ii) it allows for close supervision; iii) it results in better development of applied skills. Moreover, it demonstrates that the face-to-face component of a hybrid learning system does much more than just maintain human contact

Sensitivity for self-discrepancy predicts alcohol consumption in alcohol- dependent inpatients with high self-consciousness

Background: A specific sense of self and sensitivity to self-threatening situations among alcohol-dependent (AD) individuals has often been reported by clinicians. Unpleasant self-awareness of situations of personal failure may lead to relapse, especially for AD individuals with high self-consciousness. However, the implication of Higgins’ self-discrepancy theory for alcohol-dependence has not yet been empirically investigated. This study tested the relation between self-discrepancies evaluated by the Self-Discrepancy Questionnaire and different self-related dimensions (i.e., self-consciousness, depression, emotional regulations strategies) in alcohol-dependence. Methods: Forty-four AD inpatients (28 men) presenting with an Axis-1 diagnosis of alcohol-dependence (DSMIV) and recruited during detoxification process completed Self-Discrepancy Questionnaire and others self-related questionnaires. Results: High self-discrepancies and associated distress were related to more negative affect, depression, abstract-analytical ruminations, and to lower adaptive emotion regulation strategies and higher alcohol craving and alcohol intake. Self-discrepancies and associated distress predicted alcohol intake but only in high selfconsciousness AD population. Conclusion: Self-discrepancies lead to discomfort and to emotional distress, which may results of more nonadaptive ruminations and less adaptive emotion regulation strategies. This unpleasant awareness of self-discrepancy predicted higher alcohol craving and alcohol intake. Two subpopulations were distinguished by the sensitivity to selfdiscrepancy according to their level of self-consciousness

Vers une meilleure compréhension du processus d'habituation à l'observateur humain: Une approche statistique chez Macaca leonina (Primates: Cercopithecidea)

peer reviewedHabituation allows an observer to closely approach and follow free-ranging animals, as they no longer respond to the observer presence (e.g., through flight, avoidance, display, curiosity). While habituation is implicitly acknowledged as a necessary step before any direct observational studies of primates, there is very little published data on the subject. The aim of this study is to analyse the habituation process over time (17 months) in a wildfeeding troop of northern pigtailed macaques (Macaca leonina) inhabiting a degraded forest fragment of the Sakaerat Biosphere Reserve, Thailand. Based on the number of encounters, contact duration with the studied troop, and behavioural responses to the observer recorded ad libitum and via scan sampling, we found statistical evidence of habituation progress over five stages: early, minimal, partial, advanced, and full. The complete habituation process took nearly 13 months. Factors such as the macaques’ limited experience of human contact, semi-terrestriality, large ranging patterns, fission-fusion dynamics, unpredictable resource use, as well as reduced native fruit availability in this degraded forest fragment may explain the length of the process. It was only possible to collect ranging and behavioural data from the partial habituation stage, although these data were biased toward adult males and sub-adults, while overestimating movement behaviour over inactivity and social behaviours. Our results highlight the importance of analysing behavioural data of fully habituated groups of primates to limit biases of observer presence, and also of not underestimating the habituation process length. This study provides novel information on the habituation process in macaques and proposes an effective methodology to analyse the habituation process across a wide range of primate species.Northern Pigtailed Macaque Projec

Disease recognition is related to specific autobiographical memory deficits in alcohol-dependence

The particularly high treatment gap in alcohol-dependence suggests the existence of important barriers to treatment decision and in particular difficulties in problem recognition. This study tested the relation between problem recognition and self-related memories. Forty-one recently detoxified alcohol-dependent individuals (AD) were compared to twenty alcoholic subjects that were abstinent for 6 months or more (recruited among alcoholics-anonymous (AA)), and to twenty controls on autobiographical memories elicited by pictures depicting or not alcohol using the autobiographical memory test. Autonoetic consciousness was measured with the Remember/Know paradigm. We tested whether memories performances were related with data obtained on the readiness to change questionnaire (RCQ) or with consciousness of the severity of drinking. AD subjects provided less specific memories than control and AA subjects, and fewer Remember responses than controls. The deficits in AD subjects were not specific for memories elicited by pictures depicting alcohol, suggesting a global deficit. Autobiographical memories specificity was negatively correlated to scores of consciousness of the severity of drinking but not to RCQ. Our results support potential recovery of autobiographical memory with abstinence. AD’s deficits in autobiographical memory were related to capacities to recognize the severity and therefore may be a barrier to treatment decision

Tubectomy of Pregnant and Non-pregnant Female Balinese Macaques (Macaca Fascicularis) With Post-operative Monitoring

peer reviewedWorldwide, primates, and humans increasingly share habitats and often enter in conflict when primates thrive in human-dominated environments, calling for special management measures. Reproductive control is increasingly used to manage population growth but very few monitoring data are available. Therefore, the efficiency and implications of such programs require a careful examination. In the context of a contraception program in wild female long-tailed macaques in Ubud, Bali, conducted over four successive campaigns between 2017 and 2019, including 140 females (i.e., 41.9% of the reproductive females of the population in 2019), modifications of an endoscopic tubectomy procedure, a permanent sterilization method, clinical evaluation of this method, and the post-operative monitoring results of the neutered females after release are described. This surgical approach was applicable for pregnant females: 28.6% of the treated females were pregnant at the time of the surgery. The procedure used a single lateral port to reach and cauterize both oviducts in non-pregnant as well as in early to mid-term pregnant females. Pregnant females nearer to term required a second lateral port to access both oviducts masked by the size of the gravid uterus. Moreover, bipolar thermocauterization was utilized successfully without resection to realize the tubectomy. The average duration of the laparoscopic surgery was 14 min for non-pregnant females and 22 min for pregnant females. Animals were released 3 h 22 min in average following their capture. This short holding time, recommended for free-ranging primates, was made possible by the minimal invasiveness of the sterilization approach. A laparoscopic post-operative evaluation conducted on two patients during the following campaign confirmed that the oviducts were definitely disrupted and no longer patent. Moreover, no new pregnancies in sterilized females were recorded during the 3-year observation period. The survival rate of the treated females 6 months after sterilization was high (96.3%) with no major post-operative complications clinically recorded. Among females that were pregnant during surgery, 81.1% were confirmed to experience term delivery. This study demonstrates the safety and efficiency of endoscopic tubectomy, even for pregnant females, as a mean of wild macaques' population control