Challenges of operational river forecasting

Skillful and timely streamflow forecasts are critically important to water managers and emergency protection services. To provide these forecasts, hydrologists must predict the behavior of complex coupled human–natural systems using incomplete and uncertain information and imperfect models. Moreover, operational predictions often integrate anecdotal information and unmodeled factors. Forecasting agencies face four key challenges: 1) making the most of available data, 2) making accurate predictions using models, 3) turning hydrometeorological forecasts into effective warnings, and 4) administering an operational service. Each challenge presents a variety of research opportunities, including the development of automated quality-control algorithms for the myriad of data used in operational streamflow forecasts, data assimilation, and ensemble forecasting techniques that allow for forecaster input, methods for using human-generated weather forecasts quantitatively, and quantification of human interference in the hydrologic cycle. Furthermore, much can be done to improve the communication of probabilistic forecasts and to design a forecasting paradigm that effectively combines increasingly sophisticated forecasting technology with subjective forecaster expertise. These areas are described in detail to share a real-world perspective and focus for ongoing research endeavors

Mechanisms of spontaneous melanomia regression in melim pigs

Le mélanome est la forme la plus agressive des cancers cutanés et les formes invasives sont résistantes aux thérapies classiques. L objectif principal de cette thèse a été l étude des mécanismes de la régression spontanée dans un modèle porcin de mélanome cutanée (MeLiM). Par une approche de biologie intégrative utilisant des techniques d étude du transcriptome (HSS, puce ADN) et de caractérisation phénotypique des cellules du microenvironnement tumoral nous avons disséqué le processus de régression au niveau cellulaire et moléculaire. Ce travail a également permis de montrer qu il existe des similarités entre le transcriptome du mélanome chez le porc et chez l homme en plus de celles déjà observées au niveau clinique et génétique. D ores et déjà, ce travail apporte des cibles à utiliser pour développer des traitements contre le mélanome chez l homme.Melanoma is the most aggressive form of skin cancer. The invasive form of the disease exhibits resistance to classical therapy. The overall objective of this PhD was to investigate mechanisms of spontaneous tumor regression using a porcine melanoma model (MeLiM). We applied an approach of integrative biology composed of transcriptomic techniques (SSH and DNA chips) and the phenotypic characterization of cells in the tumor microenvironment. By these means, we deciphered the process of regression on a cellular and molecular level. This work allowed us to point out similarities between porcine and human melanoma on the transcriptomic level along with the already observed parallels on the clinical and genetic level. Already, this work contributes to human anti-melanoma therapy as it provides potential targets that could be used for developing new strategies.VERSAILLES-BU Sciences et IUT (786462101) / SudocSudocFranceF

[Mn(bipyridyl)(CO)3Br]: An Abundant Metal Carbonyl Complex as Efficient Electrocatalyst for CO2 Reduction

International audienc

Catalyse homogène efficace de la réduction électrochimique de l'oxyde nitreux en diazote sur des catalyseurs de type rhénium-carbonyle

International audienceWe show that reduced rhenium bipyridyl carbonyl complexes are stable and selective catalysts for deoxygenation of nitrous oxide (N2O) in organic media in the presence of water. Mechanistic studies indicate that the Re complex is initially reduced to produce the activated species. N2O then binds to labile position at the reduced metal and the resulting adduct is further reduced to trigger N–O bond breaking and release of N2. Proton donors are beneficial to enhance the catalytic rate and to reduce the energy required to generate potential limiting intermediate. These results open directions for N–O bond activation.Dans cette publication, nous montrons que les complexes réduits de rhénium bipyridylcarbonyle sont des catalyseurs stables et sélectifs pour la désoxygénation du protoxyde d'azote (N2O) en milieu organique en présence d'eau. Des études mécanistiques indiquent que le complexe Re est initialement réduit pour produire l'espèce catalytique active. Le N2O se coordine ensuite au métal réduit et complexe résultant est encore réduit pour déclencher la rupture de la liaison N-O et la libération de N2. La présence de donneurs de protons est bénéfique pour améliorer l'efficacité catalytique et pour réduire l'énergie requise pour générer l'intermédiaire réactionnel limitant. Ces résultats ouvrent des perspectives pour l'activation de la liaison N-O

Controlled Potential Electrolysis: Transition from Fast to Slow Regimes in Homogeneous Molecular Catalysis. Application to the Electroreduction of CO₂ Catalyzed by Iron Porphyrin

International audienceMolecular catalysis of electrochemical reactions is a field of intense activity because of the current interest in electrifying chemical transformations, including both electrosynthesis of organic molecules and production of fuels via small molecule activation. Controlled potential electrolysis (CPE) is often coupled with in situ in operando spectroscopic methods with the aim to gather mechanistic information regarding the catalytic species involved. Herein, considering a simple mechanism for a homogeneous molecular catalysis of an electrochemical reaction, we establish the concentration profile of the catalyst in the electrolysis cell enabling to envision the information that can be obtained from the coupling of this CPE with a spectroscopic probe in the cell compartment. We show how the characteristic parameters of the system (catalytic rate constant, cell dimensions and stirring rate) affect the response with particular emphasis on the transition between two limiting cases, namely a ‘fast’ catalysis regime where catalysis only takes place in a small layer adjacent to the electrode surface and a ‘slow’ catalysis regime where catalysis takes place in the bulk of the solution. These formal concepts are then illustrated with an experimental example, the electroreduction of CO2 in dimethylformamide homogeneously catalyzed by iron tetraphenylporphyrin and followed by UV-vis spectroscopy

Soluble {[Rh2(μ-OOCCH3)2(dbbpy)2][BF4]}n molecular wire and [Rh2(μ-OOCCH3)2(dbbpy)2L2]2+ complexes; dbbpy=4,4′-di-tert-butyl-2,2′-bipyridine: Synthesis and physicochemical characterization

International audienc

Synthesis and Structural and Physicochemical Characterization of {[Rh 2 (μ-OOCCH 3 ) 2 (dmbpy) 2 ][BF 4 ]} n Molecular Wire

International audienc

Dataset for worldwide survey of cerebrospinal total protein upper reference values

This article reports data pertaining to a worldwide web-based survey referenced in the publication “Adult CSF Total Protein: Higher upper reference limits should be considered worldwide ” (P.R. Bourque, et al., 2019). This survey was distributed to corresponding authors of the journal Neurology and the Journal of neurological sciences for the period of Jan–Dec 2017. The response rate was 36.9%. Additional results were collated through networking and national associations. There were 473 unique responses from clinical hospital laboratories in 69 countries: North America 178, South America 26, Europe 139, Africa 20, Asia 102 and Oceania 8. The upper reference limit for cerebrospinal fluid total protein ranged from 0.2 g/L to 0.8 g/L. 86.8% of the survey responses were 0.45 g/L or less. Data is presented separately for tertiary/academic and non-university/community centers

Bedrock radioactivity influences the rate and spectrum of mutation

International audienceAll organisms on Earth are exposed to low doses of natural radioactivity but some habitats are more radioactive than others. Yet, documenting the influence of natural radioactivity on the evolution of biodiversity is challenging. Here, we addressed whether organisms living in naturally more radioactive habitats accumulate more mutations across generations using 14 species of waterlice living in subterranean habitats with contrasted levels of radioactivity. We found that the mitochondrial and nuclear mutation rates across a waterlouse species’ genome increased on average by 60% and 30%, respectively, when radioactivity increased by a factor of three. We also found a positive correlation between the level of radioactivity and the probability of G to T (and complementary C to A) mutations, a hallmark of oxidative stress. We conclude that even low doses of natural bedrock radioactivity influence the mutation rate possibly through the accumulation of oxidative damage, in particular in the mitochondrial genome