11,115 research outputs found

    Hunting and sale of Pangolins across Sub-Saharan Africa: a preliminary analysis

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    Pangolins (Pholidota: Manidae) are hunted and traded for their meat and scales. We conducted preliminary analyses on the hunting and sale at markets of four species of pangolin across Sub-Saharan Africa based on data from the OFFTAKE database. Our analyses show that all four species of African pangolin are hunted and sold at markets throughout much of Sub-Saharan Africa. The proportion of pangolins as part of the total vertebrates hunted has increased significantly during the 43 years, from 1972-2014, for which we have data

    Induced encystment improves resistance to preservation and storage of Acanthamoeba castellanii

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    Several conditions that allow the preservation, storage and rapid, efficient recovery of viable Acanthamoeba castellanii organisms were investigated. The viability of trophozoites (as determined by time to confluence) significantly declined over a period of 12 months when stored at −70°C using dimethyl sulfoxide (DMSO; 5 or 10%) as cryopreservant. As A. castellanii are naturally capable of encystment, studies were undertaken to determine whether induced encystment might improve the viability of organisms under a number of storage conditions. A. castellanii cysts stored in the presence of Mg2+ at 4°C remained viable over the study period, although time to confluence was increased from approximately 8 days to approximately 24 days over the 12-month period. Storage of cysts at −70°C with DMSO (5 or 10%) or 40% glycerol, but not 80% glycerol as cryopreservants increased their viability over the 12-month study period compared with those stored at room temperature. Continued presence of Mg2+ in medium during storage had no adverse effects and generally improved recovery of viable organisms. The present study demonstrates that A. castellanii can be stored as a non-multiplicative form inexpensively, without a need for cryopreservation, for at least 12 months, but viability is increased by storage at −70°C

    Hands-on Gravitational Wave Astronomy: Extracting astrophysical information from simulated signals

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    In this paper we introduce a hands-on activity in which introductory astronomy students act as gravitational wave astronomers by extracting information from simulated gravitational wave signals. The process mimics the way true gravitational wave analysis will be handled by using plots of a pure gravitational wave signal. The students directly measure the properties of the simulated signal, and use these measurements to evaluate standard formulae for astrophysical source parameters. An exercise based on the discussion in this paper has been written and made publicly available online for use in introductory laboratory courses.Comment: 5 pages, 4 figures; submitted to Am. J. Phy

    A Role for the Vacuolating Cytotoxin, VacA, in Colonization and Helicobacter pylori-Induced Metaplasia in the Stomach

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    Carriage of Helicobacter pylori strains producing more active (s1/i1) forms of VacA is strongly associated with gas-tric adenocarcinoma. To our knowledge, we are the first to determine effects of different polymorphic forms of VacA on inflammation and metaplasia in the mouse stomach. Bacteria producing the less active s2/i2 form of VacA colonized mice more efficiently than mutants null for VacA or producing more active forms of it, providing the first evidence of a positive role for the minimally active s2/i2 toxin. Strains producing more active toxin forms induced more severe and extensive metaplasia and in flammation in the mouse stomach than strains producing weakly active (s2/i2) toxin. We also examined the association in humans, controlling for cag PAI status. In human gastric biopsy specimens, the vacA i1 allele was strongly associated with precancerous intestinal metaplasia, with almost complete absence of intestinal metaplasia in subjects infected with i2-type strains, even in a vacA s1, cagA+ background

    Effects of diabetes and hypertension on glomerular transforming growth factor-β receptor expression

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    Effects of diabetes and hypertension on glomerular transforming growth factor-β receptor expression.BackgroundSeveral studies have suggested that transforming growth factor-β1 (TGF-β1) is an important determinant of diabetic glomerular injury. TGF-β1 forms a heteromeric complex with two cellular receptor subtypes, designated TGF-β RII and TGF-β RI, but the effects of diabetes mellitus on glomerular TGF-β receptor expression have not been completely elucidated. We first compared the effect of experimental type I diabetes mellitus and uninephrectomy on glomerular TGF-β receptor expression in spontaneously hypertensive rats (SHRs), and then sought to determine whether changes in TGF-β receptor expression were strain specific by studying normotensive Wistar-Kyoto (WKY) rats.MethodsFive groups of male SHRs were studied. The first group received streptozotocin (60 mg/kg IV) and was studied after one week. The second group received streptozotocin and was studied after two weeks. The third group received streptozotocin (60 mg/kg IV) but received insulin to maintain euglycemia. The fourth group of age-matched SHRs served as the control group, while a fifth group of SHRs underwent uninephrectomy. Four groups of male WKY rats were also studied. The first group of WKY rats served as the age-matched control group. The second group of WKY rats received streptozotocin, while a third group of WKY rats underwent uninephrectomy. The fourth group underwent uninephrectomy and received streptozotocin. At each time point, glomeruli were isolated for protein extraction, and the protein was subjected to Western blot analysis of TGF-β RII and TGF-β RI expression.ResultsBasal expression of both TGF-β receptors per microgram of glomerular protein was similar in normotensive WKY rats and hypertensive SHRs. Hyperglycemia (blood glucose level, 17.8 ± 2.9 mmol/L) led to an early twofold increase in TGF-β RII protein expression and a fourfold increase in TGF-β RI protein expression in the glomeruli of hypertensive diabetic SHRs compared with euglycemic SHRs (blood glucose level, 5.8 ± 0.8 mmol/L), which was sustained after two weeks. Insulin treatment (blood glucose level, 5.2 ± 0.9 mmol/L) normalized both TGF-β RII and TGF-β RI expression in the glomeruli of SHRs that received streptozotocin. Glomerular capillary hypertension in the uninephrectomized SHRs led to a twofold increase in glomerular TGF-β RII protein expression, but did not reproduce the effect of diabetes mellitus on TGF-β RI expression. In contrast to the findings in SHRs, neither hyperglycemia (blood glucose level, 15.5 ± 2.1 mmol/L), uninephrectomy, nor hyperglycemia (blood glucose level, 16.8 ± 3.0 mmol/L) and uninephrectomy altered TGF-β receptor expression in the glomeruli of normotensive WKY rats.ConclusionThese studies support the hypothesis that hemodynamic factors and metabolic factors influence glomerular TGF-β receptor in vivo in the SHRs

    ISPAN (Interactive Stiffened Panel Analysis): A tool for quick concept evaluation and design trade studies

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    Interactive Stiffened Panel Analysis (ISPAN) modules, written in FORTRAN, were developed to provide an easy to use tool for creating finite element models of composite material stiffened panels. The modules allow the user to interactively construct, solve and post-process finite element models of four general types of structural panel configurations using only the panel dimensions and properties as input data. Linear, buckling and post-buckling solution capability is provided. This interactive input allows rapid model generation and solution by non finite element users. The results of a parametric study of a blade stiffened panel are presented to demonstrate the usefulness of the ISPAN modules. Also, a non-linear analysis of a test panel was conducted and the results compared to measured data and previous correlation analysis

    Hungry for change: the Sydney Food Fairness Alliance

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    The Sydney Food Fairness Alliance is one of a growing number of nascent food movements in Australia to have emerged out of concern for the country’s food future, as well as the deleterious effect the present food system is having on its citizens’ health and the continent’s fragile environment. The Alliance’s structure and activities clearly position it as a new social movement (NSM) engaged in collective action on a specific issue, in this instance, food security/justice, and operating outside the political sphere while aiming to influence and affect societal change. Food security as a human right lies at the heart of the Alliance’s philosophy, and equitable, sustainable food policies for New South Wales are a core focus of its advocacy work. The authors argue that the Alliance is a distinctive food movement in that it positions itself as an \u27umbrella\u27 organization representing a wide range of stakeholders in the food system. This chapter reflects on the values, achievements, issues of concern, strengths and weaknesses, and future of the Sydney Food Fairness Alliance. This resource is Chapter 8 in \u27Food Security in Australia: Challenges and Prospects for the Future\u27 published by Springer in 2013
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