Effective peer assessment processes: Research findings and future directions

Despite the popularity of peer assessment (PA), gaps in the literature make it difficult to describe exactly what constitutes effective PA. In a literature review, we divided PA into variables and then investigated their interrelatedness. We found that (a) PA's psychometric qualities are improved by the training and experience of peer assessors; (b) the development of domain-specific skills benefits from PA-based revision; (c) the development of PA skills benefits from training and is related to students' thinking style and academic achievement, and (d) student attitudes towards PA are positively influenced by training and experience. We conclude with recommendations for future research.

ZAP-70 intron1 DNA methylation status: Determination by pyrosequencing in B chronic lymphocytic leukemia

ZAP-70 expression is a strong prognostic indicator in chronic lymphocytic leukemia. However, ZAP-70 quantification by flow cytometry lacks sufficient standardization. Based upon the correlation between ZAP-70 expression and its gene methylation status, we have developed a quantitative pyrosequencing assay for the determination of ZAP-70 methylation adapted for routine use. Methylation in four CpG pairs (C-223, C-243, C-254, and C-267) in the first intron of ZAP-70 is associated with repression of ZAP-70. Moreover, it correlates with CD38 expression (n=111, p<.0001), IgHv mutation status (n=106, p<.0001), time to treatment (p<.0001), and overall survival (p=.0014). Pyrosequencing of ZAP-70 provides a good alternative to flow cytometry.

The Holocene occurrence of cold water corals in the NE Atlantic: Implications for coral carbonate mound evolution

U-series dating of constructional cold-water corals is a powerful tool to reconstruct the evolution of corals on carbonate mounds. Here we have investigated the time framework of corals such as Lophelia pertusa and Madrepora oculata on five different mound settings of the eastern North Atlantic (on Rockall Bank and in Porcupine Seabight), sampled at variable depth and location (610–880 m water depth). We have found that the past 11 ka reflect a period generally favourable for coral development. We further determined local mound growth rates and identified mound surface erosion (framework collapse) during times of active coral framework construction. “Local” vertical mound growth rates vary between less than 5 cm ka − 1 and up to 220 cm ka − 1 . We interpret rates exceeding 15 cm ka − 1 as representative of densely populated coral reefs. During times of reduced or absent coral development, mound evolution rates are by far smaller (0 to 10 ng g − 1 ) with 232 Th. To complete the coral growth records in cases, a few AMS 14 C ages were measured. Those AMS 14 C ages have been obtained according to the procedures described by ( Frank et al., 2004 ) and have been calibrated using the marine 14 C calibration of CALIB510 ( Stuiver et al., 1998 ) with a mean sub-surface water reservoir age of 500 ± 100 a ( Frank et al., 2004 ). 4 Results 4.1 U-series dating results Results of U-series dating of coral fragments are presented in Table 2 . The U concentration of cold-water species Lophelia pertusa and Madrepora oculata varies strongly between ~ 2.80 and ~ 5.0 μg g − 1 . Initial δ 234 U 0 values range between 140‰ and 155‰ with a mean of 148 ± 3.5‰ ( n = 63; standard deviation = ± 2 σ ) identical to measured present day seawater values of 146.6–149.6‰ ( Delanghe et al., 2002; Robinson et al., 2004 ). Measured 232 Th concentrations are small ( 70 cm ka − 1 ( Fig. 3 a). The initial start of the reef after the Younger Dryas cold reversal (12.9–11.5 ka calibrated BP) is followed by a period of rapid mound growth between 9.5 and 8.5 ka (~ 60 cm ka − 1 ), which is unfortunately poorly dated so far ( Fig. 3 a). Next, VMGR is 4 times lower (~ 15 cm ka − 1 ) until 6 ka followed again by a period of more rapid coral fragment accumulation from 6 to 5 ka. The VMGR is close to zero or at least strongly reduced thereafter at 4.4 ± 0.4 ka, 2.9 ± 0.1 ka, and at 1.9 ± 0.3 ka. In between those intervals of almost absent coral fragment deposition, VMGR are high (40 to 70 cm ka − 1 ). Finally during the past 1.5 ka the reef evolves again at a rate of ~ 30 cm ka − 1 ( Fig. 3 a). Core 55G located in close vicinity of core 54G but at shallower depth of 640 m reveals similar coral ages, but a strongly disturbed age–depth relationship ( Fig. 3 b). Note that the core is composed of mainly Madrepora oculata fragments, a species which construct a thinner and likely more unstable open framework. The dominant age reversal recorded between 70 and 156 cm core depth demonstrates clearly coral debris redistribution likely through physical erosion. This layer corresponds to a core section filled mainly with “coral rubble” (small broken fragments barely visible in the X-ray images) ( Fig. 2 -[3]). Corals in this section are about 9.4 ka to 11 ka old and are thus of equal ages compared to corals obtained at the base of core 54G. Consequently, we may assume that the M. oculata reef started to develop on top of exposed hardgrounds about 11 ka ago as did the Lophelia pertusa reef at deeper water depth (core 54G). During the Holocene, corals have than been displaced as a consequence of physical mound erosion. Below this section corals seem in chronological order and the few fragments dated reveal ages between 8 and 3 ka, but the resulting VMGRs are 15 cm ka − 1 , but local VMGRs can exceed 200 cm ka − 1 . Over the past 11 ka we have found first evidence of temporal changes in reef activity as coral abundances and mound growth rates decline to less than 10 cm ka − 1  at 1.8–2.0 ka, 4.2–4.8 ka and 6–8 ka. Moreover, the onset of the decline of corals activity coincides with a cold climate reversal at 8.2 ka. In addition, we have confirmed that periods favourable for coral growth on SW Rockall Bank and in Porcupine Seabight are related to overall climatic warm phases (MIS 1, 5, 7) and that coral growth is largely reduced or even absent “on mounds” during cold phases such as glacial periods and even MIS 3. Thus, coral growth records follow a glacial/interglacial pattern and are discontinuous in time and space. Detailed chronological studies, however, provide first evidence that those ecosystems are sensitive to even small changes of environmental conditions such as productivity, current activity and potentially water mass density affected by climate change. Finally, the reconstruction of mound evolution during the past 11 ka provides further constrains on mound evolution on geological time scales as it clearly highlights the strong variability of the vertical mound growth rates on solely a few thousand years and on less than a few cm core depth. Acknowledgements This work was funded through the European Union (projects: ECOMOUND, GEOMOUND, and HERMES : EVK3-CT-1999-00013, 00016 and GOCE-CT-2005-511234-1 ) and by the French Centre National de la Recherche Scientifique (CNRS) and the Commisariat à l'Energie Atomique (CEA) . We thank IPEV (Institut Polaire Emile Victor), the members and crew of GEOMOUND Marion Dufresne cruise, for their excellent work recovering these unique sediment cores and deep-water corals presented here. David van Rooij is a post-doctoral fellow of the FWO Flanders. O. Weber, M. Cremer and S. Saint-Paul (DGO, University Bordeaux) are acknowledged for their support with the SCOPIX analyses. Thanks to the constructive comments and critical questions of Augusto Mangini, Christine Hatté and an anonymous reviewer this manuscript has greatly improved. Furthermore, the work is part of the ESF Eurodiversity project MiCROSYSTEMS. References Abrantes, 1998 Abrantes F. Sediment fluxes along the northeastern European Margin: inferring hydrological changes between 20 and 8 kyr Marine Geology 152 1998 7 23 Adkins et al., 1998 Adkins J.F. Cheng H. Boyle E.A. Druffel E.R.M. Edwards R.L. 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Microstructure evolution of HP40-Nb alloys during aging under air at 1000 °C

Two as-cast HP 40 alloys provided by different manufacturers were aged at 1000 °C under\udlaboratory air. They had the same as-cast microstructure consisting of austenite dendrites\uddelineated by a network of eutectic Nb-rich MC and Cr-rich M7C3 carbides. After aging for\udseveral months, they showed similar microstructures in the bulk materials, though M7C3\udcarbides have been replaced by M23C6 carbides. As expected, a sub-surface zone depleted in\udchromium has appeared where a tetragonal CrNbC could be identified in both materials.\udHowever, the composition of the transition zones between the surface and the bulk\udmaterials differed, mainly because one of the materials underwent significant nitrogen\udpick-up with associated precipitation of M6(C,N) and M2(C,N) phases. On the contrary, the\udother alloy did show only one intermediate zone with a mix of CrNbC, M23C6 and MC\udcarbides. A full account of the microstructures observed in the aged materials is given

Menopause and modifiable coronary heart disease risk factors: A population based study

The aim of our study was to determine the effect of the menopause on various coronary heart disease (CHD) risk factors and on the global risk of CHD in a population based sample of women, making the difference between menopause and age related effects.

Role of the ghrelin/obestatin balance in the regulation of neuroendocrine circuits controlling body composition and energy homeostasis

Ghrelin and obestatin are two peptides isolated from the gastrointestinal tract and encoded by the same preproghrelin gene. They convey to the central nervous system informations concerning the nutritional status and/or the energy stores. Ghrelin, mostly acting through the GH secretagogue receptor GHS-R, is a potent GH secretagogue, an orexigenic peptide and a long-term regulator of energy homeostasis. Obestatin was initially described for its anorexigenic effects and its binding to the G protein-coupled receptor 39 (GPR39). However, the role of obestatin is still controversial and the nature of the obestatin receptor remains an open question. This review is focussed on the possible implication of the ghrelin/obestatin system in psychiatric diseases with particular emphasis on eating disorders.

Développement d’actions de prévention du VIH, des hépatites et des infections sexuellement transmissibles chez les immigrants consultant dans les missions France de Médecins du monde

The mission France of Doctors of the World has for objective to facilitate the access to care and to rights in the common law system for vulnerable populations and to bring testimonies out. The objective of the project is to ensure daily actions of prevention: to bring people to screen for HIV and hepatitis as well as obtaining full access to treatment for populations consulting in the Reception centers for Care and Orientation (RCCO). The screening is proposed systematically to all new patients (90% of them are immigrants) after a medical consultation or a special prevention consultation. The prevalence of HIV, hepatitis B and C was respectively 15, 10.5, and 7 times higher than the national average among patients screened in 2007, The centers of Doctors of the World are privileged places to inform, prevent, offer screening, and bring healthcare to this population particularly exposed to risks.

Polyarthrite chronique et tuberculose

S05-04. Evolutionary diversity and developmental dynamics of X-chromosome inactivation

X-chromosome inactivation ensures dosage compensation for X-linked genes products in mammals. In eutherian mammals, X inactivation is controlled by the non-coding Xist transcript and is believed to be random, with either the paternal or maternal X chromosome being chosen for silencing. In mice, where most studies on the developmental timing of X inactivation have been conducted, Xist expression is initially imprinted and only the paternal X chromosome is inactivated during early mouse development and in extraembryonic tissues. This imprinted form of X inactivation is reversed in the inner cell mass, after which random X inactivation takes place in embryonic lineages. Whether this complex pattern of Xist expression and X-inactivation dynamics exists in other mammals remains unclear. Indeed, the degree to which the X-inactivation process is conserved between different mammals remains an open question. For example, marsupials have no Xist gene and show exclusive paternal X inactivation in all lineages. We have investigated X inactivation during early embryogenesis in other mammals such as rabbits, and find that the kinetics and monoallelic regulation of X inactivation are very different to the situation in mice. Our results suggest that although some molecular mechanisms are shared, there is remarkable evolutionary diversity in the developmental events underlying dosage compensation in different mammals.

Experimental and numerical study on effect of forming rate on AA5086 sheet formability

International audienceWith increasing application of aluminum alloys in automotive or aeronautic industries, it is necessary to characterize their deformation behaviors at large strains, high strain rates and elevated temperatures, which is relatively lacking today. The aim of this paper is to experimentally and numerically investigate the influence of forming rate and temperature on formability of an AA5086 sheet. Firstly, tensile tests are carried out at different temperatures (20, 230, 290 and 350 ◦C) and at different forming rates (10, 750 and 1000 mm/s). A technique of digital image correlation (DIC) associated with a high-speed camera is applied to evaluate the surface strains and a complete procedure is built to detect the onset of localized necking during the experiments. The influences of initial testing temperature and forming rate on the sheet formability are analyzed. Then in order to numerically determine the formability of this sheet, a form of Voce's constitutive law taking into account the temperature and strain rate is proposed. An inverse analysis is carried out to identify the material parameters of the law for the tested aluminum alloy. Finally, with the above identified law, tensile tests are simulated. The experimental and numerical results show that the testing temperature and forming rate have a great influence on sheet formability. At high forming rates, the sheet formability of AA5086 is lowered up to a certain temperature, above this temperature, the formability is greatly enhanced. Furthermore, the agreement between experimental and numerical results indicates that the proposed constitutive law and the identified material parameters can be appropriate to model the sensitivity of AA5086 sheet towards strain rate and temperature