Etude expérimentale du ruissellement et de l'érosion sur les terres agricoles de Siliana (Tunisie)

Cette étude propose une méthode de mesure des érosions aérolaires sur les sols calcimagnésiques plus ou moins encroûtés et emblavés du terroir de Siliana, en Tunisie centrale semi aride recevant moins de 400 mm de pluies. Elle entre dans les thèmes de recherches des programmes HYDROMED et AMBRE sur les potentialités et risques de petits bassins versants alimentant des retenues ou des barrages collinaires. Les informations de base proviennent de parcelles expérimentales soumises à une simulation de pluies selon des protocoles respectant les situations culturales et les énergies des précipitations naturelles de cette région. Cette analyse utilise les relations (R(I)) s'établissant entre les intensités de ruissellements et les intensités des pluies puis celles s'établissant entre les charges solides et les intensités de ruissellements (Cs(R)). Cette analyse est confrontée avec celle des intensités des pluies naturelles (I max 5') susceptibles de provoquer les premiers ruissellements pour différentes situations culturales saisonnières. Cette analyse est à l'origine du modèle MOBIL. Les résultats montrent que lorsque les premières pluies tombent sur des sols fraîchement labourés l'érosion aréolaire annuelle moblise 5,5 t/ha/an en année normale (P 369 mm et Rsi 57 t.m/ha.h) et 8,0 t/ha/an en année agressive (P 588 mm, Rsi 130). La majorité de l'érosion annuelle (50 à 80%) provient des périodes orageuses post-récolte. Si les premières pluies arrivent avant les labours, les érosions deviennent très importantes avec, respectivement, quelque 20 et 40 t/ha/an. Les risques érosifs sont liés au décalage entre les périodes de préparation des terres et d'apparition des pluies : un labour à grosses mottes est susceptible d'infiltrer les premières averses violentes de la saison pluvieuse... (D'après résumé d'auteur

Superconducting properties of very high quality NbN thin films grown by high temperature chemical vapor deposition

Niobium nitride (NbN) is widely used in high-frequency superconducting electronics circuits because it has one of the highest superconducting transition temperatures ($T_c$ $\sim$ 16.5 K) and largest gap among conventional superconductors. In its thin-film form, the $T_c$ of NbN is very sensitive to growth conditions and it still remains a challenge to grow NbN thin film (below 50 nm) with high $T_c$. Here, we report on the superconducting properties of NbN thin films grown by high-temperature chemical vapor deposition (HTCVD). Transport measurements reveal significantly lower disorder than previously reported, characterized by a Ioffe-Regel ($k_F$$\ell$) parameter of $\sim$ 14. Accordingly we observe $T_c$ $\sim$ 17.06 K (point of 50% of normal state resistance), the highest value reported so far for films of thickness below 50 nm, indicating that HTCVD could be particularly useful for growing high quality NbN thin films

MLb-LDLr: A Machine Learning Model for Predicting the Pathogenicity of LDLr Missense Variants

Untreated familial hypercholesterolemia (FH) leads to atherosclerosis and early cardiovascular disease. Mutations in the low-density lipoprotein receptor (LDLr) gene constitute the major cause of FH, and the high number of mutations already described in the LDLr makes necessary cascade screening or in vitro functional characterization to provide a definitive diagnosis. Implementation of high-predicting capacity software constitutes a valuable approach for assessing pathogenicity of LDLr variants to help in the early diagnosis and management of FH disease. This work provides a reliable machine learning model to accurately predict the pathogenicity of LDLr missense variants with specificity of 92.5% and sensitivity of 91.6%. © 2021 The Author

The ethical desirability of moral bioenhancement: A review of reasons

Background: The debate on the ethical aspects of moral bioenhancement focuses on the desirability of using biomedical as opposed to traditional means to achieve moral betterment. The aim of this paper is to systematically review the ethical reasons presented in the literature for and against moral bioenhancement. Discussion: A review was performed and resulted in the inclusion of 85 articles. We classified the arguments used in those articles in the following six clusters: (1) why we (don't) need moral bioenhancement, (2) it will (not) be possible to reach consensus on what moral bioenhancement should involve, (3) the feasibility of moral bioenhancement and the status of current scientific research, (4) means and processes of arriving at moral improvement matter ethically, (5) arguments related to the freedom, identity and autonomy of the individual, and (6) arguments related to social/group effects and dynamics. We discuss each argument separately, and assess the debate as a whole. First, there is little discussion on what distinguishes moral bioenhancement from treatment of pathological deficiencies in morality. Furthermore, remarkably little attention has been paid so far to the safety, risks and side-effects of moral enhancement, including the risk of identity changes. Finally, many authors overestimate the scientific as well as the practical feasibility of the interventions they discuss, rendering the debate too speculative. Summary: Based on our discussion of the arguments used in the debate on moral enhancement, and our assessment of this debate, we advocate a shift in focus. Instead of speculating about non-realistic hypothetical scenarios such as the genetic engineering of morality, or morally enhancing 'the whole of humanity', we call for a more focused debate on realistic options of biomedical treatment of moral pathologies and the concrete moral questions these treatments raise

Could Moral Enhancement Interventions be Medically Indicated?

This paper explores the position that moral enhancement interventions could be medically indicated (and so considered therapeutic) in cases where they provide a remedy for a lack of empathy, when such a deficit is considered pathological. In order to argue this claim, the question as to whether a deficit of empathy could be considered to be pathological is examined, taking into account the difficulty of defining illness and disorder generally, and especially in the case of mental health. Following this, Psychopathy and a fictionalised mental disorder (Moral Deficiency Disorder) are explored with a view to consider moral enhancement techniques as possible treatments for both conditions. At this juncture, having asserted and defended the position that moral enhancement interventions could, under certain circumstances, be considered medically indicated, this paper then goes on to briefly explore some of the consequences of this assertion. First, it is acknowledged that this broadening of diagnostic criteria in light of new interventions could fall foul of claims of medicalisation. It is then briefly noted that considering moral enhancement technologies to be akin to therapies in certain circumstances could lead to ethical and legal consequences and questions, such as those regarding regulation, access, and even consent

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century