Ecology Drives the Worldwide Distribution of Human Diseases

Identifying the factors underlying the origin and maintenance of the latitudinal diversity gradient is a central problem in ecology, but no consensus has emerged on which processes might generate this broad pattern. Interestingly, the vast majority of studies exploring the gradient have focused on free-living organisms, ignoring parasitic and infectious disease (PID) species. Here, we address the influence of environmental factors on the biological diversity of human pathogens and their global spatial organization. Using generalized linear multivariate models and Monte Carlo simulations, we conducted a series of comparative analyses to test the hypothesis that human PIDs exhibit the same global patterns of distribution as other taxonomic groups. We found a significant negative relationship between latitude and PID species richness, and a nested spatial organization, i.e., the accumulation of PID species with latitude, over large spatial scales. Additionally, our results show that climatic factors are of primary importance in explaining the link between latitude and the spatial pattern of human pathogens. Based on our findings, we propose that the global latitudinal species diversity gradient might be generated in large part by biotic interactions, providing strong support for the idea that current estimates of species diversity are substantially underestimated. When parasites and pathogens are included, estimates of total species diversity may increase by more than an order of magnitude

β-Cyclodextrins grafted with chiral amino acids: A promising supramolecular stabilizer of nanoparticles for asymmetric hydrogenation?

International audienceWater-soluble ruthenium nanoparticles stabilized by randomly methylated β-cyclodextrins (RaMeCDs) grafted with chiral amino-acid moieties like l-alanine (Ala) and l-leucine (Leu) were prepared in aqueous solution by two approaches: (i) a one-step hydrogen reduction of ruthenium trichloride as metal source in the presence of appropriate cyclodextrins (one-pot method) or (ii) a NaBH4 reduction of the metal salts, followed by the stabilization of ruthenium hydrosol by the addition of chirally modified RaMeCDs (cascade method). The influence of the ligand's nature and the synthesis methodologies on the size, dispersion and surface properties of the obtained ruthenium colloids were studied by TEM and NMR analyses. The spherical ruthenium suspensions contain very small particles (0.82-1.00 nm) with narrow size distributions. Their catalytic properties were evaluated in biphasic hydrogenation of various prochiral compounds (olefins, ketones and disubstituted arenes) showing promising results in terms of activity and selectivity. Nevertheless, no significant enantiomeric excesses were observed

An Introduction to Drug Discovery by Probing Protein-Substrate Interactions Using Saturation Transfer Difference-Nuclear Magnetic Resonance (STD-NMR).

International audienceNMR spectroscopy is a powerful tool for characterizing and identifying mols. and nowadays is even used to characterize complex systems in biol. In the expt. presented here, students learned how to apply this modern technique to probe interactions between small mols. and proteins. With the use of simple org. synthesis, students prepd. different analogs of the well-known anxiolytic drug, nitrazepam. This study constituted the students' first approach into the drug-discovery field and encouraged the students to think about how to improve the design of drugs in a rational way. [on SciFinder(R)

Trimethylaluminum and borane complexes of primary amines.

International audienceTrimethylaluminum (TMA) complexes of methyl-, n-propyl-, cyclopropyl-, allyl-, and propargylamine were synthesized and their experimental properties and theoretical characteristics were compared with the respective amine-borane analogues. The amine ligand of an amine-TMA Lewis acid-base complex can be easily changed by another amine through a 2:1 amine-TMA intermediate in pentane at room temperature. The exchange of the same ligands in the case of amine-boranes requires remarkably more time in line with the calculated relative energy of the respective transition state. The (1)H and (13)C NMR experiments examining the addition of one or more equivalent of amine to the respective Lewis acid-base complex conclude in the fast exchange of the amine ligand in the NMR time scale only in the cases of amine-TMA complexes, which could also be caused by similar 2:1 complexes. However, in gas phase, only 1:1 amine-TMA complexes are present as evidenced by ultraviolet photoelectron spectroscopy (UPS). The observed UP spectra, which are the first recorded photoelectron spectra of primary amine-TMA compounds, indicate that the stabilization effect of the lone electron pair of nitrogen atom in amines during the borane complexation is stronger than that of the TMA complexation. In line with this observation, the destabilization of the σ(Al-C) orbitals is lower than that of σ(B-H) orbitals during the formation of amine-TMA and amine-borane complexes, respectively. As showed by theoretical calculations, the CH(4) elimination of the studied amine-TMA complexes is exothermic, indicating the possibility of using these compounds in metal organic chemical vapor deposition techniques (MOCVD). On the other hand, our experimental conditions avoid this methane elimination and constitutes the first procedure employing distillation to isolate primary amine-TMA complexes

Polyhydroxylated ammonium chloride salt: a new efficient surfactant for nanoparticles stabilisation in aqueous media. Characterization and application in catalysis

International audienc

Horner-Wadsworth-Emmons Reaction of Unprotected Sugars in Water or in the Absence of Any Solvent: One-Step Access to C-Glycoside Amphiphiles

International audienceThe synthesis of C-glycosides in water or in the absence of any solvent from free sugars and β-keto phosphonates is reported. The methodology permits a one-step access to C-glycoside amphiphiles in moderate-to-good yields. The selectivity (α/β and furanoside/pyranoside) is discussed and a process that leads to pure β-C-pyranosides is also described

Sustainable Development Goal n° 3, "health and well-being", and the need for more integrative thinking

Recently, the United-Nations adopted 17 sustainable development goals for the 2030 Agenda. The Sustainable Development Goal (SDG) 3 "Ensuring a healthy life and promoting well-being for all ages" is one of the most transversal goals, which is interconnected with the other SDGs. The health and well-being are the aim of this goal and also, they are the result of other goals that empower people to develop better in different social, economic and productive areas. The SDG 3 is a multiple and universal resource on which sustainable development policies can be based, in particular for the most needed countries, and can lead to the sustainable maintenance of well-being and health. However, SDG 3 faces a high sectorization, so there is a risk of not being able to achieve the stated objectives. Only a national and international reflection on human population and animal health surveillance devices, environmental health, implementation of appropriate indicators and specific research funding will ensure the balance between the legitimacy of society's demands and the needs of scientific and medical excellence. The health and well-being indicators that are needed to achieve the agenda goals are based on reliable and relevant quantitative data, which are currently rare or even non-existent in some regions. Therefore, it is now necessary to initiate a more integrative international animal and public health and research strategy in order to collect new data, particularly those relating to current emerging infectious diseases that affect public and animal health, especially in developing countries

Chapitre 7. L’ODD 3, ou la nécessité d’une approche de santé globale

L’Objectif de développement durable 3 « Bonne santé et bienêtre » est parmi les 17 Objectifs de l’Agenda 2030 l’un des plus transversaux et interconnectés aux autres. Intervenant soit en tant que facteur, soit en tant que conséquence découlant d’actions entreprises dans l’un des autres ODD, l’ODD 3 constitue un levier démultiplié et universel sur lequel asseoir une politique de développement durable, notamment pour les pays les plus démunis. Les indicateurs de santé et de bien-être nécessaires à l’atteinte de cet Objectif impliquent l’existence de données quantitatives fiables et pertinentes qui sont aujourd’hui rares, voire inexistantes. Une véritable stratégie de recherche et de santé publique internationale, tenant compte des politiques nationales, doit ainsi être initiée pour acquérir de nouvelles données de santé, notamment celles relatives aux maladies de génération, en particulier dans les pays du Sud. À défaut de pouvoir atteindre les objectifs fixés, une réflexion générale sur les dispositifs de surveillance des populations et l’adoption de stratégies nouvelles reposant sur le choix et la mise en œuvre d’indicateurs pertinents, soutenus par des financements de recherche dédiés, garantiront l’équilibre entre la légitimité de la demande sociétale et les impératifs d’excellence scientifique et médicale. De réels effets sur la santé et le bien-être des populations sont à ce prix

Un défi pour la planète : les Objectifs de développement durable en débat

L'Objectif de développement durable 3 "Bonne santé et bien-être" est parmi les 17 Objectifs de l'Agenda 2030 l'un des plus transversaux et interconnectés aux autres. Intervenant soit en tant que facteur, soit en tant que conséquence découlant d'actions entreprises dans l'un des autres ODD, l'ODD 3 constitue un levier démultiplié et universel sur lequel asseoir une politique de développement durable, notamment pour les pays les plus démunis. Les indicateurs de santé et de bien-être nécessaires à l'atteinte de cet Objectif impliquent l'existence de données quantitatives fiables et pertinentes qui sont aujourd'hui rares, voire inexistantes. Une véritable stratégie de recherche et de santé publique internationale, tenant compte des politiques nationales, doit ainsi être initiée pour acquérir de nouvelles données de santé, notamment celles relatives aux maladies de génération, en particulier dans les pays du Sud. À défaut de pouvoir atteindre les objectifs fixés, une réflexion générale sur les dispositifs de surveillance des populations et l'adoption de stratégies nouvelles reposant sur le choix et la mise en oeuvre d'indicateurs pertinents, soutenus par des financements de recherche dédiés, garantiront l'équilibre entre la légitimité de la demande sociétale et les impératifs d'excellence scientifique et médicale. De réels effets sur la santé et le bien-être des populations sont à ce prix