The CD81 Partner EWI-2wint Inhibits Hepatitis C Virus Entry

Two to three percent of the world's population is chronically infected with hepatitis C virus (HCV) and thus at risk of developing liver cancer. Although precise mechanisms regulating HCV entry into hepatic cells are still unknown, several cell surface proteins have been identified as entry factors for this virus. Among these molecules, the tetraspanin CD81 is essential for HCV entry. Here, we have identified a partner of CD81, EWI-2wint, which is expressed in several cell lines but not in hepatocytes. Ectopic expression of EWI-2wint in a hepatoma cell line susceptible to HCV infection blocked viral entry by inhibiting the interaction between the HCV envelope glycoproteins and CD81. This finding suggests that, in addition to the presence of specific entry factors in the hepatocytes, the lack of a specific inhibitor can contribute to the hepatotropism of HCV. This is the first example of a pathogen gaining entry into host cells that lack a specific inhibitory factor

Pollination and biological control research: are we neglecting two billion smallholders

Food insecurity is a major world problem, with ca. 870 million people in the world being chronically undernourished. Most of these people live in tropical, developing regions and rely on smallholder farming for food security. Solving the problem of food insecurity is thought to depend, in part, on managing ecosystem services, such as the pollination of crops and the biological control of crop pests, to enhance or maintain food production. Our knowledge regarding regulating ecosystem services in smallholder-farmed (or dualistic) landscapes is limited and whilst pollination has been the focus of considerable research, the provision of natural enemy services, important for every crop worldwide, has been relatively neglected. In order to assess whether ecosystem-service research adequately represents smallholder-farmed landscapes, whilst also considering climatic region and national economic status, we examined the constituent studies of recent quantitative reviews relevant to biological control and pollination. No regulating ecosystem service meta-analysis, to our knowledge, has focussed on smallholder agriculture despite its importance to billions of peoples’ local food security. We found that whilst smallholdings contributed 16% of global farmland area and 83% of the global agricultural population (estimated using FAO’s World Census of Agriculture 2000) only 22 of 190 studies (12%), overall, came from smallholder-farmed landscapes. These smallholder studies mostly concerned coffee production (16 studies). Individual reviews of biological control were significantly and strongly biased towards data from large-scale farming in temperate regions. In contrast pollination reviews included more smallholder studies and were more balanced for climate regions. The high diversity of smallholder-farmed landscapes implies that more research will be needed to understand them compared to large-scale landscapes but we found far more research from the latter. We highlight that these skews in research effort have implications for sustainable intensification and the food security of billions in the developing world. In particular we urge for balance in future ecosystem-services research and synthesis by greater consideration of a diverse range of smallholder-farmed landscapes in Africa and continental Asia

Recherche et etude des levures amylolytiques en vue de la production d'alcool a partir de substrats amylaces

SIGLECNRS-CDST / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

On the SAR derived alert in the detection of oil spills according to the analysis of the EGEMP

Satellite services that deliver information about possible oil spills at sea currently use different labels of “confidence” to describe the detections based on radar image processing. A common approach is to use a classification differentiating between low, medium and high levels of confidence. There is an ongoing discussion on the suitability of the existing classification systems of possible oil spills detected by radar satellite images with regard to the relevant significance and correspondence to user requirements. This paper contains a basic analysis of user requirements, current technical possibilities of satellite services as well as proposals for a redesign of the classification system as an evolution towards a more structured alert system. This research work offers a first review of implemented methodologies for the categorisation of detected oil spills, together with the proposal of explorative ideas evaluated by the European Group of Experts on satellite Monitoring of sea-based oil Pollution (EGEMP)

Myeloid stem cell kinetics in children hypertransfused during remission induction of acute lymphoblastic leukemia.

Experimental studies in animals and recent preliminary clinical evidence raised the possibility that hypertransfusion might be capable of producing a beneficial effect on granulopoiesis recovery following irradiation or chemotherapy. This prompted us to design a study to determine the effect of hypertransfusion on the blood and marrow CFU-c of leukemic children during remission induction. Nineteen children with acute lymphoblastic leukemia have been randomized in pairs to normotransfused (Hb: 12-14 g/dl) and hypertransfused (Hb: 16-18 g/dl) groups. Anti-leukemic chemotherapy (vincristine and adriamycin weekly during 4 weeks and prednisone daily) was identical in all children. As expected, suppression of erythropoiesis was observed in the hypertransfused group. During the first three courses of chemotherapy, the number of marrow CFU-c remained very low in both groups. One week after the third course of chemotherapy the number of bone marrow CFU-c began to increase in both groups. One week after course four the CFU-c value was significantly larger in the hypertransfused group. We also observed that circulating CFU-c were almost absent before induction chemotherapy, whereas their number increased after course three and was higher in the hypertransfused group and remained higher after course four. These results show the kinetics of bone marrow recovery after chemotherapy and suggest that hypertransfusion increases the rate of recovery of granulopoiesis