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991.
Mwanahamuntu MH Sahasrabuddhe VV Kapambwe S Pfaendler KS Chibwesha C Mkumba G Mudenda V Hicks ML Vermund SH Stringer JS Parham GP 《PLoS medicine》2011,8(5):e1001032
Groesbeck Parham and colleagues describe their Cervical Cancer Prevention Program in Zambia, which has provided services to over 58,000 women over the past five years, and share lessons learned from the program's implementation and integration with existing HIV/AIDS programs. 相似文献
992.
Paulo Corti Aaron B. A. Shafer David W. Coltman Marco Festa-Bianchet 《Conservation Genetics》2011,12(1):119-128
Small populations in fragmented habitats can lose genetic variation through drift and inbreeding. The huemul (Hippocamelus bisulcus) is an endangered deer endemic to the southern Andes of Chile and Argentina. Huemul numbers have declined by 99% and its
distribution by 50% since European settlement. The total population is estimated at less than 2,000 individuals and is highly
fragmented. At one isolated population in Chilean Patagonia we sampled 56 individuals between 2005 and 2007 and genotyped
them at 14 microsatellite loci. Despite low genetic variability (average 2.071 alleles/locus and average H
O of 0.341), a low inbreeding coefficient (F
IS) of 0.009 suggests nearly random mating. Population genetic bottleneck tests suggest both historical and contemporary reductions
in population size. Simulations indicated that the population must be maintained at 75% of the current size of 120 individuals
to maintain 90% of its current genetic diversity over the next 100 years. Potential management strategies to maintain genetic
variability and limit future inbreeding include the conservation and establishment of habitat corridors to facilitate gene
flow and the enlargement of protected areas to increase effective population size. 相似文献
993.
Factors influencing wolf <Emphasis Type="Italic">Canis lupus</Emphasis> roadkills in Northwest Spain
Victor Javier Colino-Rabanal Miguel Lizana Salvador J. Peris 《European Journal of Wildlife Research》2011,57(3):399-409
Roadkill is one of the most prominent causes of wildlife mortality. Much research effort has focussed on collisions with ungulates
because of traffic safety. However, studies about large carnivore roadkills are scarce despite vehicles being a main cause
of mortality. The absence of studies can be explained in part because of difficulties in obtaining sufficient sample sizes.
We collected data from locations of 82 wolf roadkill sites in the Castilla y León Region, northwest Spain. We evaluated different
models to characterise collision localities using logistic regressions with corrections for rare events. The best models included
traffic and human disturbance parameters. Landscape variables did not improve predictive power. Fencing was a decisive key
predictor; roadkill was proportionally higher along fenced highways than on similar major roads that lacked fences. Wolf–vehicle
collisions were more common in agricultural areas, although wolf densities were lower in these zones. Both the higher density
of important roads and a greater proportion of roaming wolves on the plateau may explain this pattern. 相似文献
994.
Wu H Pomeroy SL Ferreira M Teider N Mariani J Nakayama KI Hatakeyama S Tron VA Saltibus LF Spyracopoulos L Leng RP 《Nature medicine》2011,17(3):347-355
The TP53 gene (encoding the p53 tumor suppressor) is rarely mutated, although frequently inactivated, in medulloblastoma and ependymoma. Recent work in mouse models showed that the loss of p53 accelerated the development of medulloblastoma. The mechanism underlying p53 inactivation in human brain tumors is not completely understood. We show that ubiquitination factor E4B (UBE4B), an E3 and E4 ubiquitin ligase, physically interacts with p53 and Hdm2 (also known as Mdm2 in mice). UBE4B promotes p53 polyubiquitination and degradation and inhibits p53-dependent transactivation and apoptosis. Notably, silencing UBE4B expression impairs xenotransplanted tumor growth in a p53-dependent manner and overexpression of UBE4B correlates with decreased expression of p53 in these tumors. We also show that UBE4B overexpression is often associated with amplification of its gene in human brain tumors. Our data indicate that amplification and overexpression of UBE4B represent previously undescribed molecular mechanisms of inactivation of p53 in brain tumors. 相似文献
995.
Leuschner F Dutta P Gorbatov R Novobrantseva TI Donahoe JS Courties G Lee KM Kim JI Markmann JF Marinelli B Panizzi P Lee WW Iwamoto Y Milstein S Epstein-Barash H Cantley W Wong J Cortez-Retamozo V Newton A Love K Libby P Pittet MJ Swirski FK Koteliansky V Langer R Weissleder R Anderson DG Nahrendorf M 《Nature biotechnology》2011,29(11):1005-1010
Excessive and prolonged activity of inflammatory monocytes is a hallmark of many diseases with an inflammatory component. In such conditions, precise targeting of these cells could be therapeutically beneficial while sparing many essential functions of the innate immune system, thus limiting unwanted effects. Inflammatory monocytes-but not the noninflammatory subset-depend on the chemokine receptor CCR2 for localization to injured tissue. Here we present an optimized lipid nanoparticle and a CCR2-silencing short interfering RNA that, when administered systemically in mice, show rapid blood clearance, accumulate in spleen and bone marrow, and localize to monocytes. Efficient degradation of CCR2 mRNA in monocytes prevents their accumulation in sites of inflammation. Specifically, the treatment attenuates their number in atherosclerotic plaques, reduces infarct size after coronary artery occlusion, prolongs normoglycemia in diabetic mice after pancreatic islet transplantation, and results in reduced tumor volumes and lower numbers of tumor-associated macrophages. 相似文献
996.
997.
Louren?o PM Sousa CA Seixas J Lopes P Novo MT Almeida AP 《Journal of vector ecology》2011,36(2):279-291
Malaria is dependent on environmental factors and considered as potentially re-emerging in temperate regions. Remote sensing data have been used successfully for monitoring environmental conditions that influence the patterns of such arthropod vector-borne diseases. Anopheles atroparvus density data were collected from 2002 to 2005, on a bimonthly basis, at three sites in a former malarial area in Southern Portugal. The development of the Remote Vector Model (RVM) was based upon two main variables: temperature and the Normalized Differential Vegetation Index (NDVI) from the Moderate Resolution Imaging Spectroradiometer (MODIS) Terra satellite. Temperature influences the mosquito life cycle and affects its intra-annual prevalence, and MODIS NDVI was used as a proxy for suitable habitat conditions. Mosquito data were used for calibration and validation of the model. For areas with high mosquito density, the model validation demonstrated a Pearson correlation of 0.68 (p<0.05) and a modelling efficiency/Nash-Sutcliffe of 0.44 representing the model's ability to predict intra- and inter-annual vector density trends. RVM estimates the density of the former malarial vector An. atroparvus as a function of temperature and of MODIS NDVI. RVM is a satellite data-based assimilation algorithm that uses temperature fields to predict the intra- and inter-annual densities of this mosquito species using MODIS NDVI. RVM is a relevant tool for vector density estimation, contributing to the risk assessment of transmission of mosquito-borne diseases and can be part of the early warning system and contingency plans providing support to the decision making process of relevant authorities. 相似文献
998.
999.
Hoek KG Van Rie A van Helden PD Warren RM Victor TC 《Molecular diagnosis & therapy》2011,15(4):189-194
Despite numerous intervention strategies, including the direct observed short-course treatment strategy and improved diagnostic methods, the incidence of multidrug-resistant and extensively drug-resistant tuberculosis (TB) continues to rise globally. Many treatment policies are based on the model that acquisition of drug resistance in already infected individuals drives the drug-resistant TB epidemic, hence the focus on drug-resistance testing of retreatment cases. However, molecular epidemiology and mathematical modeling suggest that the majority of multidrug-resistant TB cases are due to ongoing transmission of multidrug-resistant strains. This is most likely the result of diagnostic delay, thereby emphasizing the need for rapid diagnostics and comprehensive contact tracing, as well as active case finding. Current diagnosis of TB in low-income, high-burden regions relies on smear microscopy and clinical signs and symptoms. However, this smear-centered approach has many pitfalls, including low sensitivity in HIV patients and children, the inability of smear to reveal drug-resistance patterns, and the need for sampling on consecutive days. In order to address these limitations, efforts have been made to expand access to Mycobacterium tuberculosis culture and drug susceptibility testing. However, the slow growth rate of the causative agent, M. tuberculosis, contributes to significant diagnostic delay. Molecular-based diagnostic methods, targeting mutations that are known to confirm drug resistance, are capable of significantly reducing diagnostic delay. Two such methods, the line-probe assay and the real-time PCR-based Xpert? MTB/RIF assay, have been described. The latter test shows particular promise for smear-negative and extrapulmonary specimens. This may prove especially useful in settings where co-infection rates with HIV are high. However, since most research focuses on the performance of both of these assays, further investigations need to be done regarding the impact of the routine implementation of these assays on TB control programs and the cost effectiveness thereof. 相似文献
1000.
Specimens of Starksia were collected throughout the western Atlantic, and a 650-bp portion of the mitochondrial gene cytochrome oxidase-c subunit I (COl) was sequenced as part of a re-analysis of species diversity of western Central Atlantic shorefishes. A neighbor-joining tree constructed from the sequence data suggests the existence of several cryptic species. Voucher specimens from each genetically distinct lineage and color photographs of vouchers taken prior to dissection and preservation were examined for diagnostic morphological characters. The results suggest that Starksia atlantica, Starksia lepicoelia, and Starksia sluiteri are species complexes, and each comprises three or more species. Seven new species are described. DNA data usually support morphological features, but some incongruence between genetic and morphological data exists. Genetic lineages are only recognized as species if supported by morphology. Genetic lineages within western Atlantic Starksia generally correspond to geography, such that members of each species complex have a very restricted geographical distribution. Increasing geographical coverage of sampling locations will almost certainly increase the number of Starksia species and species complexes recognized in the western Atlantic. Combining molecular and morphological investigations is bringing clarity to the taxonomy of many genera of morphologically similar fishes and increasing the number of currently recognized species. Future phylogenetic studies should help resolve species relationships and shed light on patterns of speciation in western Atlantic Starksia. 相似文献