The influence of a grain boundary on the thermal transport properties of bulk, melt-processed Y-Ba-Cu-O

in Superconductor Science and Technology (2013), 26

We report the dependence of thermal conductivity, thermoelectric power and electrical resistivity on temperature for a bulk, large grain melt-processed Y-Ba-Cu-O (YBCO) high temperature superconductor ... [more ▼]

We report the dependence of thermal conductivity, thermoelectric power and electrical resistivity on temperature for a bulk, large grain melt-processed Y-Ba-Cu-O (YBCO) high temperature superconductor (HTS) containing two grains separated by a well-defined grain boundary. Transport measurements at temperatures between 10 and 300 K were carried out both within one single grain (intra-granular properties) and across the grain boundary (inter-granular properties). The influence of an applied external magnetic field of up to 8 T on the measured sample properties was also investigated. The presence of the grain boundary is found to affect strongly the electrical resistivity of the melt-processed bulk sample, but has almost no effect on its thermoelectric power and thermal conductivity, within experimental error. The results of this study provide direct evidence that the heat flow in multi-granular melt-processed YBCO bulk samples should be virtually unaffected by the presence of grain boundaries in the material. © 2013 IOP Publishing Ltd. [less ▲]

Predicting funds of hedge funds attrition through performance diagnostics

in Gregoriou, Greg (Ed.) Reconsidering Funds of Hedge Funds (2013)

The analysis of individual mutual funds survivorship reveals that a model based on the consideration of a wide class of performance measures can be a solid predictor of their disappearance. Given the ... [more ▼]

The analysis of individual mutual funds survivorship reveals that a model based on the consideration of a wide class of performance measures can be a solid predictor of their disappearance. Given the importance of performance fees, this phenomenon is likely to be all the more relevant for funds of hedge funds. In this analysis, we apply a diagnostics methodology to predict the disappearance of funds of hedge funds from databases, which we consider a sign of their attrition. Our research shows that prediction is also possible for these types of hedge funds, and even that the predictive ability of the model is stronger than for mutual funds. [less ▲]

Sirtuin 1 enzymatic activity is required for cartilage homeostasis in vivo in a mouse model.

in Arthritis and Rheumatism (2013), 65(1), 159-66

OBJECTIVE: We and others previously demonstrated that sirtuin 1 (SIRT-1) regulates apoptosis and cartilage-specific gene expression in human chondrocytes and mouse models. This study was undertaken to ... [more ▼]

OBJECTIVE: We and others previously demonstrated that sirtuin 1 (SIRT-1) regulates apoptosis and cartilage-specific gene expression in human chondrocytes and mouse models. This study was undertaken to determine if SIRT-1 enzymatic activity plays a protective role in cartilage homeostasis in vivo, by investigating mice with SIRT-1 mutations to characterize their cartilage. METHODS: Articular cartilage was harvested from the paws and knees of 5- and 6-month-old wild-type (WT) mice and mice homozygous for SIRT-1(tm2.1Mcby) (SIRT-1(y/y) ), an allele carrying a point mutation that encodes a SIRT-1 protein with no enzymatic activity (y/y mice). Mice ages 2 days old and 6-7 days old were also examined. Mouse joint cartilage was processed for histologic examination or biochemical analyses of chondrocyte cultures. RESULTS: We found that articular cartilage tissue sections from y/y mice of up to 6 months of age contained reduced levels of type II collagen, aggrecan, and glycosaminoglycan compared to sections from WT mice. In contrast, protein levels of matrix metalloproteinase 8 (MMP-8), MMP-9, and MMP-13 were elevated in the cartilage of y/y mice. In addition, chondrocyte apoptosis was elevated in SIRT-1 mutant mice as compared to their WT littermates. Consistent with these observations, protein tyrosine phosphatase 1b was elevated in the y/y mice. CONCLUSION: Our in vivo findings in this animal model demonstrate that mice with defective SIRT-1 also have defective cartilage, with elevated rates of cartilage degradation with age. Hence, normal cartilage homeostasis requires enzymatically active SIRT-1 protein. [less ▲]

Use of GFP whole cell microbial biosensors for the investigation of the scale-up and scale-down effect on biopharmaceutical processes

Book published by Momentum press (2013)

Carnet de pédiatrie: Physiologie rénale

Learning material (2013)

physiologie rénale: module complémentaire à la néphrologie de l'enfant

an attempt of time calibration of the Lower Tournaisian (Hastarian Substage) based on orbitally forced sequences

in Document de l'Institut Scientifique, Rabat (2013), 26

Analyse des divergences entre forêts communautaires et permis de gré à gré au Gabon

E-print/Working paper (2013)

Peut-on améliorer l'enseignement de concepts scientifiques par la mise en place d'un dispositif de collaboration en formation initiale des enseignants ?

in Puzzle (2013), 32(2), 100-102

Mineralogy and geochemistry of phosphates and silicates in the Sapucaia pegmatite, Minas Gerais, Brazil: genetical implications.

in Canadian Mineralogist (2013), 50

Rapid Plant Invasion in Distinct Climates Involves Different Sources of Phenotypic Variation

in PLoS ONE (2013), 8(1), 55627

When exotic species spread over novel environments, their phenotype will depend on a combination of different processes, including phenotypic plasticity (PP), local adaptation (LA), environmental maternal ... [more ▼]

When exotic species spread over novel environments, their phenotype will depend on a combination of different processes, including phenotypic plasticity (PP), local adaptation (LA), environmental maternal effects (EME) and genetic drift (GD). Few attempts have been made to simultaneously address the importance of those processes in plant invasion. The present study uses the well-documented invasion history of Senecio inaequidens (Asteraceae) in southern France, where it was introduced at a single wool-processing site. It gradually invaded the Mediterranean coast and the Pyrenean Mountains, which have noticeably different climates. We used seeds from Pyrenean and Mediterranean populations, as well as populations from the first introduction area, to explore the phenotypic variation related to climatic variation. A reciprocal sowing experiment was performed with gardens under Mediterranean and Pyrenean climates. We analyzed climatic phenotypic variation in germination, growth, reproduction, leaf physiology and survival. Genetic structure in the studied invasion area was characterized using AFLP. We found consistent genetic differentiation in growth traits but no home-site advantage, so weak support for LA to climate. In contrast, genetic differentiation showed a relationship with colonization history. PP in response to climate was observed for most traits, and it played an important role in leaf trait variation. EME mediated by seed mass influenced all but leaf traits in a Pyrenean climate. Heavier, earlier-germinating seeds produced larger individuals that produced more flower heads throughout the growing season. However, in the Mediterranean garden, seed mass only influenced the germination rate. The results show that phenotypic variation in response to climate depends on various ecological and evolutionary processes associated with geographical zone and life history traits. Seeing the relative importance of EME and GD, we argue that a “local adaptation vs. phenotypic plasticity” approach is therefore not sufficient to fully understand what shapes phenotypic variation and genetic architecture of invasive populations. [less ▲]