925 research outputs found
Sindbis virus infects specific gut cells for replication and dissemination from the posterior midgut of mosquitoes
Abstract
Sindbis virus (SINV), a member of the genus Alphavirus, is the protype virus used to gain insight into other disease-causing Alphaviruses. As a mosquito-borne-virus (arbovirus), SINV transit in adult female mosquitoes includes attachment to the gut lumen and entry into the midgut cells, followed by replication and dissemination into the hemolymph through yet unknown specific mechanisms. Free-mated adult females, aged day 5-7, were fed a viremic bovine blood suspension via blood sausage at a final SINV titer at 107 PFU/ml. Midguts from fully engorged mosquitoes were dissected on day 5 and 7 post-bloodmeal and further examined by immunolabeling using FMRFamide antibody against enteroendocrine cells (EC). The results were investigated via confocal microscopy and distribution of SINV and ECs were documented. Oral infection of mosquitoes with SINV-TaV-eGFP led to GFP expression along the basal aspect of the posterior midgut (PMG) epithelial monolayer as early as day 5 p.i., persistent infection and dissemination of the virus was observed on day 30 p.i. following viremic blood feeding. ECs were observed along the entire length of the midgut with majority of ECs concentrated in the posterior midgut region. Additionally, our results demonstrated that SINV could indeed infect ECs and the accumulations of SINV associated GFP fluorescence coincided with these cells. Here we propose that ECs, positioned along the basal plasma membrane of the PMG, are involved in SINV dissemination pathway. Due to unique roles that ECs have in the exocytosis of secretory granules from the MG, these cells might serve as a gateway for virus entry into the host hemolymph. These findings suggest that midgut ECs are integral to arbovirus infection, dissemination, and availability for transmission
Dynamic changes of the extracellular matrix after acute tako-tsubo cardiomyopathy
Funding Tenovus Scotland. Grant number G13/10.Peer reviewedPublisher PD
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A History of Contemporary Independent Film Marketing in the United States (1989-1998)
This study explores the reasons for the rise in independent film's popularity, which have created a unique Hollywood phenomenon, the successful "mini-major" independent studio, dedicated to both art and commerce. Chapters cover the history of independent film, characteristics of both independent and mainstreamfilms with regards to financing, acquisition, distribution and marketing, trends within independent film in the late 1980s and 1990s, crucial distributors and landmark independent films, and key growth areas in the future for independent film
Planetary astronomy
The authors profile the field of astronomy, identify some of the key scientific questions that can be addressed during the decade of the 1990's, and recommend several facilities that are critically important for answering these questions. Scientific opportunities for the 1990' are discussed. Areas discussed include protoplanetary disks, an inventory of the solar system, primitive material in the solar system, the dynamics of planetary atmospheres, planetary rings and ring dynamics, the composition and structure of the atmospheres of giant planets, the volcanoes of IO, and the mineralogy of the Martian surface. Critical technology developments, proposed projects and facilities, and recommendations for research and facilities are discussed
The Value of Literacy Practices
The concepts of literacy events and practices have received considerable attention in educational research and policy. In comparison, the question of value, that is, āwhich literacy practices do people most value?ā has been neglected. With the current trend of cross-cultural adult literacy assessment, it is increasingly important to recognise locally valued literacy practices. In this paper we argue that measuring preferences and weighting of literacy practices provides an empirical and democratic basis for decisions in literacy assessment and curriculum development and could inform rapid educational adaptation to changes in the literacy environment. The paper examines the methodological basis for investigating literacy values and its potential to inform cross-cultural literacy assessments. The argument is illustrated with primary data from Mozambique. The correlation between individual values and respondentsā socio-economic and demographic characteristics is explored
Occurrence and population densities of yeast species in a fresh-water lake
Quantitative studies of yeasts present in surface and deep water samples from a fresh water body (Douglas Lake, Michigan) revealed 12 species ( Candida parapsilosis, C. pulcherrima, Cryptococcus albidus, Cr. diffluens, Cr. gastricus, Cr. laurentii, Rhodotorula glutinis, R. pilimanae, R. rubra, Trichosporon cutaneum, Debaryomyces sp., āblack yeastsā). In two regions of surface sampling the population densities averaged 39.6 and 5.5 cells per 100 ml respectively, whereas the average deep water count was 40.3 cells per 100 ml. Yeasts of the genus Rhodotorula predominated.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41778/1/10482_2005_Article_BF02046074.pd
Using environmental tracers to evaluate the preservation of palaeoclimate signals in aquifers of the London Basin, UK
The concept of aquifer basins as palaeoclimate archives has existed for some decades, yet few detailed studies comparing aquifer types have been carried out. To assess the potential of a particular aquifer as an archive, its hydrogeochemical characteristics must be thoroughly investigated, ideally in comparison to an adjacent aquifer which can be shown to substantially preserve its ice-age endowment at depth. The London Basin (UK) presents such an opportunity, containing two main aquifers of contrasting type: the Chalk, a fractured microporous limestone, and the Lower Greensand, a porous sandstone. Despite intensive exploitation of both, evidence for Devensian (late-glacial) water remains at depth, though this differs between aquifer type. To understand the reasons for this, a suite of environmental tracers has been applied. In addition to hydrochemistry, stable isotopes (Ī“18O, Ī“2H), carbon isotopes (Ī“13C-DIC, 14C-DIC) and noble gases (He, Ne, Ar, Kr and Xe), two tracers new to the basin (CFCs and 14C-DOC) have been used. In effect the Lower Greensand appears to be the āreference aquiferā, preserving recharge from prior to the Last Glacial Maximum (LGM), while the Chalk contains mixed water, with no remaining trace of the undiluted pre-LGM end member even at depth in remote parts of the confined basin. Whereas both aquifers had in the past given maximum 14C-DIC model agesĀ ā„Ā 30Ā kyr (the effective limit of that method), in the present study the use of 14C-DOC has reduced this to 23.4 kyr (Lower Greensand) and 17.2 kyr (Chalk). Similar contrasts in maximum stable isotope depletions (ā8.2Ā ā° and ā7.8Ā ā° Ī“18O) and noble-gas-derived recharge temperature minima (2.6Ā° and 4.1Ā Ā°C) were also observed. CFCs were found at all Chalk sites, with traces detectable even at 40Ā km from outcrop, so some climate signal degradation appears inevitable throughout the Chalk aquifer of the basin. A correlation between 14C activity and excess 4He suggests that deep saline water in the Lower Greensand could beĀ ā„Ā 50Ā kyr old. The use of 14C-DOC in particular appears to be key to understanding how reliable these individual aquifers are as palaeoarchives
Feasibility and willingness-to-pay for integrated community-based tuberculosis testing
BACKGROUND: Community-based screening for TB, combined with HIV and syphilis testing, faces a number of barriers. One significant barrier is the value that target communities place on such screening. METHODS: Integrated testing for TB, HIV, and syphilis was performed in neighborhoods identified using geographic information systems-based disease mapping. TB testing included skin testing and interferon gamma release assays. Subjects completed a survey describing disease risk factors, healthcare access, healthcare utilization, and willingness to pay for integrated testing. RESULTS: Behavioral and social risk factors among the 113 subjects were prevalent (71% prior incarceration, 27% prior or current crack cocaine use, 35% homelessness), and only 38% had a regular healthcare provider. The initial 24 subjects reported that they would be willing to pay a median 10 (IQR: 0-100) for TB testing when the question was asked in an open-ended fashion, but when the question was changed to a multiple-choice format, the next 89 subjects reported that they would pay a median 5 to get tested for TB, HIV, or syphilis. Among persons who received tuberculin skin testing, only 14/78 (18%) participants returned to have their skin tests read. Only 14/109 (13%) persons who underwent HIV testing returned to receive their HIV results. CONCLUSION: The relatively high-risk persons screened in this community outreach study placed low value on testing. Reported willingness to pay for such testing, while low, likely overestimated the true willingness to pay. Successful TB, HIV, and syphilis integrated testing programs in high risk populations will likely require one-visit diagnostic testing and incentives
Validating Measures of Third Year Medical Studentsā Use of Interpreters by Standardized Patients and Faculty Observers
Alterations in Cardiac Deformation, Timing of Contraction and Relaxation, and Early Myocardial Fibrosis Accompany the Apparent Recovery of Acute Stress-Induced (Takotsubo) Cardiomyopathy : An End to the Concept of Transience
This work was supported by grants from Tenovus Scotland and the British Heart Foundation (to Dr. Dawson, G13/10 and PG/15/108/31928, respectively). Dr. Dawson has a research agreement with Philips Healthcare and holds a material transfer agreement with AMAG Pharmaceuticals.Peer reviewedPostprin
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