80 research outputs found
An ab-initio evaluation of the local effective interactions in the familly
We used quantum chemical ab initio methods to determine the effective
parameters of Hubbard and models for the compounds (x=0
and 0.5). As for the superconducting compound we found the cobalt
orbitals above the ones by a few hundreds of meV due to the
-- hybridization of the cobalt orbitals. The correlation
strength was found to increase with the sodium content while the in-plane
AFM coupling decreases. The less correlated system was found to be the pure
, however it is still strongly correlated and very close to the Mott
transition. Indeed we found , which is the critical value for the
Mott transition in a triangular lattice. Finally, one finds the magnetic
exchanges in the layers, strongly dependant of the weak local
structural distortions
Electronic structure of the compound from ab initio local interactions
We used fully correlated ab initio calculations to determine the effective
parameters of Hubbard and t - J models for the thermoelectric misfit compound
. As for the family the Fermi level orbitals
are the orbitals of the cobalt atoms ; the being always lower
in energy by more than 240\,meV. The electron correlation is found very large
as well as the parameters fluctuations as a function of the
structural modulation. The main consequences are a partial electrons
localization and a fluctuation of the in-plane magnetic exchange from AFM to
FM. The behavior of the Seebeck coefficient as a function of temperature is
discussed in view of the ab initio results, as well as the 496\,K phase
transition
Les études poursuivies par l'Institut d'Etudes Centrafricaines, depuis sa création, sur le territoire de la République du Congo
Relevance of Brain 18F-FDG PET Imaging in Probable Seronegative Encephalitis With Catatonia: A Case Report
Autoimmune encephalitis (AIE) is a rare, severe, and rapidly progressive encephalopathy, and its diagnosis is challenging, especially in adolescent populations when the presentation is mainly psychiatric. Currently, cerebral 18-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) imaging is not included in the diagnosis algorithm. We describe a 16-year-old patient with probable seronegative encephalitis with catatonia for which several cerebral PET scans were relevant and helpful for diagnosis, treatment decision making, and follow-up monitoring. The patient recovered after 2 years of treatment with etiologic treatment of AIE and treatment of catatonia. This case suggests a more systematic assessment of the clinical relevance of 18F-FDG-PET imaging in probable seronegative AIE
Modeled O 2 nightglow distributions in the Venusian atmosphere
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96410/1/jgre3128.pd
Smart sustainable cities of the new millennium : towards design for nature
Urban environments consist of a mosaic of natural fragments, planned and unintentional habitats hosting both introduced and spontaneous species. The latter group exploits abandoned and degraded urban niches which, in the case of plants, forms what is called the Third Landscape. In the Anthropocene, cities, open spaces and buildings must be planned and designed considering not only human needs but also those of other living organisms. The scientific approach of habitat sharing is defined as Reconciliation Ecology, whilst the action of implementing the ecosystem services and functioning of such anthropogenic habitats is called Urban Rehabilitation. However, urban development still represents the main cause of biodiversity loss worldwide. Yet, the approach of planners and landscape architects highly diverges from that of ecologists and scientists on how to perceive, define and design urban green and blue infrastructure. For instance, designers focus on the positive impact that Nature (generally associated with indoor and outdoor greeneries) has on human well-being, often neglecting ecosystems’ health. Instead, considering the negative impact of any form of development and to achieve the No Net Loss Aichi’s objectives, conservationists apply mitigation hierarchy policies to avoid or reduce the impact and to offset biodiversity. The rationale of this review paper is to set the fundamentals for a multidisciplinary design framework tackling the issue of biodiversity loss in the urban environment by design for Nature. The method focuses on the building/city/landscape scales and is enabled by emerging digital technologies, i.e. Geographic Information Systems, Building Information Modelling, ecological simulation and computational design
Cdx2 homeoprotein inhibits non-homologous end joining in colon cancer but not in leukemia cells
Cdx2, a gene of the paraHox cluster, encodes a homeodomain transcription factor that plays numerous roles in embryonic development and in homeostasis of the adult intestine. Whereas Cdx2 exerts a tumor suppressor function in the gut, its abnormal ectopic expression in acute leukemia is associated to a pro-oncogenic function. To try to understand this duality, we have hypothesized that Cdx2 may interact with different protein partners in the two tissues and set up experiments to identify them by tandem affinity purification. We show here that Cdx2 interacts with the Ku heterodimer specifically in intestinal cells, but not in leukemia cells, via its homeodomain. Ku proteins do not affect Cdx2 transcriptional activity. However, Cdx2 inhibits in vivo and in vitro the DNA repair activity mediated by Ku proteins in intestinal cells. Whereas Cdx2 does not affect the recruitment of Ku proteins and DNA-PKcs into the DNA repair complex, it inhibits DNA-PKcs activity. Thus, we report here a new function of Cdx2, acting as an inhibitor of the DNA repair machinery, that may contribute to its tumor suppressor function specifically in the gut
Hierarchical regulation of the NikR-mediated nickel response in Helicobacter pylori
Nickel is an essential metal for Helicobacter pylori, as it is the co-factor of two enzymes crucial for colonization, urease and hydrogenase. Nickel is taken up by specific transporters and its intracellular homeostasis depends on nickel-binding proteins to avoid toxicity. Nickel trafficking is controlled by the Ni(II)-dependent transcriptional regulator NikR. In contrast to other NikR proteins, NikR from H. pylori is a pleiotropic regulator that depending on the target gene acts as an activator or a repressor. We systematically quantified the in vivo Ni2+-NikR response of 11 direct NikR targets that encode functions related to nickel metabolism, four activated and seven repressed genes. Among these, four targets were characterized for the first time (hpn, hpn-like, hydA and hspA) and NikR binding to their promoter regions was demonstrated by electrophoretic mobility shift assays. We found that NikR-dependent repression was generally set up at higher nickel concentrations than activation. Kinetics of the regulation revealed a gradual and temporal NikR-mediated response to nickel where activation of nickel-protection mechanisms takes place before repression of nickel uptake. Our in vivo study demonstrates, for the first time, a chronological hierarchy in the NikR-dependent transcriptional response to nickel that is coherent with the control of nickel homeostasis in H. pylori
Early liver transplantation for severe alcohol-related hepatitis not responding to medical treatment: a prospective controlled study
peer reviewedBackground: Early liver transplantation for severe alcohol-related hepatitis is an emerging treatment option. We aimed to assess the risk of alcohol relapse 2 years after early liver transplantation for alcohol-related hepatitis compared with liver transplantation for alcohol-related cirrhosis after at least 6 months of abstinence. Methods: We conducted a multicentre, non-randomised, non-inferiority, controlled study in 19 French and Belgian hospitals. All participants were aged 18 years or older. There were three groups of patients recruited prospectively: patients with severe alcohol-related hepatitis who did not respond to medical treatment and were eligible for early liver transplantation according to a new selection scoring system based on social and addiction items that can be quantified in points (early transplantation group); patients with alcohol-related cirrhosis listed for liver transplantation after at least 6 months of abstinence (standard transplantation group); patients with severe alcohol-related hepatitis not responding to medical treatment not eligible for early liver transplantation according to the selection score (not eligible for early transplantation group), this group did not enter any further liver transplantation processes. We also defined a historical control group of patients with severe alcohol-related hepatitis unresponsive to medical therapy and non-transplanted. The primary outcome was the non-inferiority of 2-year rate of alcohol relapse after transplantation in the early transplantation group compared with the standard transplantation group using the alcohol timeline follow back (TLFB) method and a prespecified non-inferiority margin of 10%. Secondary outcomes were the pattern of alcohol relapse, 2-year survival rate post-transplant in the early transplantation group compared with the standard transplantation group, and 2-year overall survival in the early transplantation group compared with patients in the not eligible for early transplantation group and historical controls. This trial is registered with ClinicalTrials.gov, NCT01756794. Findings: Between Dec 5, 2012, and June 30, 2016, we included 149 patients with severe alcohol-related hepatitis: 102 in the early transplantation group and 47 in the not eligible for early transplantation group. 129 patients were included in the standard transplantation group. 68 patients in the early transplantation group and 93 patients in the standard transplantation group received a liver transplant. 23 (34%) patients relapsed in the early transplantation group, and 23 (25%) patients relapsed in the standard transplantation group; therefore, the non-inferiority of early transplantation versus standard transplantation was not demonstrated (absolute difference 9·1% [95% CI –∞ to 21·1]; p=0·45). The 2-year rate of high alcohol intake was greater in the early transplantation group than the standard transplantation group (absolute difference 16·7% [95% CI 5·8–27·6]) The time spent drinking alcohol was not different between the two groups (standardised difference 0·24 [95% CI −0·07 to 0·55]), but the time spent drinking a large quantity of alcohol was higher in the early transplantation group than the standard transplantation group (standardised difference 0·50 [95% CI 0·17–0·82]). 2-year post-transplant survival was similar between the early transplantation group and the standard transplantation group (hazard ratio [HR] 0·87 [95% CI 0·33–2·26]); 2-year overall survival was higher in the early transplantation group than the not eligible for early transplantation group and historical controls (HR 0·27 [95% CI 0·16–0·47] and 0·21 [0·13–0·32]). Interpretation: We cannot conclude non-inferiority in terms of rate of alcohol relapse post-transplant between early liver transplantation and standard transplantation. High alcohol intake is more frequent after early liver transplantation. This prospective controlled study confirms the important survival benefit related to early liver transplantation for severe alcohol-related hepatitis; and this study provides objective data on survival and alcohol relapse to tailor the management of patients with severe alcohol-related hepatitis. Funding: The present study has been granted by the French Ministry of Health—Programme Hospitalier de Recherche Clinique 2010
Camille Saint-Saëns, journalist and music critic (1870-1921)
Compositeur, pianiste et organiste, fondateur de la Société nationale de musique, Camille Saint-Saëns (1835-1921) est une personnalité essentielle de la musique française. Célèbre pour ses prises de position affirmés, Saint-Saëns s'est abondamment exprimé par voie de presse, pendant plus de cinquante années (de 1870 à 1921) sur des sujets aussi divers que l'étaient ses centres d'intérêts. Bien que certains écrits, aient été ensuite publiés sous forme de recueils, beaucoup d'autres sont tombés dans l'oubli. En traduisant les goûts, les choix esthétiques de leur auteur, ces textes révèlent aussi ceux de ses contemporains et les luttes artistiques dans lesquelles ils étaient engagés et dont Saint-Saëns se faisait bien souvent le porte-parole. Ces écrits révèlent aussi un pan de la vie de l'interprète et du compositeur - du moins ce qu'il a bien voulu livrer au public - et contribuent ainsi, à brosser un éloquent tableau de l'histoire de la musique française sous le Troisième République.Composer, pianist and organist, founder of the Société nationale de musique, Camille Saint-Saëns (1835-1921) is essential in French music. He was renowned for his forthright pronouncements, Saint-Saëns expressed his opinions profusely in newspapers and magazines (from 1870 to 1921) on topics as diverse as his range of interests. Although some of these articles were published as collections, many others have fallen into obscurity. By revealing the tastes, the aesthetic choices of their author, these texts reveals also those of his contemporaries and the artistic debates in which they were involved. They also light the hidden part of the life of the composer and contribute to enrich history of French musical life under Third Republic
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