241 research outputs found

    Local and Regional Aspects of Habitat Quality Jointly Affect the Biodiversity of Ephemeral Ponds

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    The biodiversity of local communities is likely affected by both local habitat quality and by the quality of the landscape surrounding the locality. In pond environments, habitat quality may be affected by the kind of leaf litter present because leaf species differ in the kind of habitat structure they provide and the rate at which they release nutrients into the water. Landscape quality could affect diversity as well; some landscapes provide a richer pool of potential colonists. In addition, the plant community surrounding ponds could alter the influence of habitat selection: animals may prefer to colonize ponds that have litter which matches that kind of litter typically produced by plants in the surrounding landscape (e.g. if organisms are adapted to the litter types in the habitats where they occur). We conducted a split-plot randomized block experiment to examine how both landscape and local scale properties, and their interaction, affect biodiversity within temporary pond communities in eastern NC. We manipulated both the kind of landscape in which artificial ponds were located (open-canopy grassland, pine forest, and hardwood forest) and the leaf species (sedge, pine, or maple) present in artificial ponds. Ponds were open to colonization by amphibians and aquatic insects during the summer of 2010. We surveyed organisms in the ponds on a monthly basis and did a complete census of each pond at summer's end.   The kind of plant community (landscape) had consistent, strong effects on biodiversity throughout the experiment: ponds in open-canopy landscapes supported more species and different kinds of species than ponds in forested systems. Litter type affected biodiversity in the monthly catch-and-release samples, with more species in sedge treatments than pine treatments. We also found evidence from the monthly samples to suggest biodiversity was enhanced to a greater extent in open canopy ponds when litter from open canopy environments was present but that biodiversity in closed canopy environments was affected less by the kind of litter present. Our results highlight the importance of the terrestrial matrix surrounding ponds on biodiversity within the ponds, and it could aid conservation efforts aimed at maintaining the unique biodiversity of temporary ponds.  M.S

    Issues in interactive interface design and evaluation

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    This work is a practical exploration of the interactive interface. The purpose is to provide a step-by-step guideline for the design and evaluation of interactive multimedia interfaces intended for limited-use training programs, delivering specific content to well-defined user groups. The discussions are intended for new or seasoned interface designers looking for a comprehensive collection of best practices, procedures, suggestions, observations and experiences to help conceive, design, develop, approve, test and evaluate interfaces for single or series-based interactive multimedia delivered on CD-ROM or diskette. These discussions are illustrated with interfaces from three different interactive training program series designed for pharmaceutical and biotechnical companies

    Comparison of the myocardial clearance of endothelial progenitor cells injected early versus late into reperfused or sustained occlusion myocardial infarction

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    Stem cell transplantation following AMI has shown promise for the repair or reduction of the amount of myocardial injury. There is some evidence that these treatment effects appear to be directly correlated to cell residence time. This study aims to assess the effects of (a) the timing of stem cell injection following myocardial infarction, and (b) flow milieu, on cell residence times at the site of transplantation by comparing three time points (day of infarction, week 1 and week 4-5), and two models of acute myocardial infarction (sustained occlusion or reperfusion). Twenty-one dogs received 2 injections of 30 million endothelial progenitor cells. The first injections were administered by epicardial (n = 8) or endocardial injection (n = 13) either on the day of infarction (n = 15) or at 1 week (n = 6). The second injections were administered by only endocardial injection (n = 18) 4 weeks following the first injection. Cell clearance half-lives were comparable between early and late injections. However, transplants into sustained occlusion infarcts resulted in slower cell clearance 77.1 ± 6.1 (n = 18) versus reperfused 59.4 ± 2.9 h (n = 21) p = 0.009. Sustained occlusion infarcts had longer cell retention in comparison to reperfusion whereas the timing of injection did not affect clearance rates. If the potential for myocardial regeneration associated with cell transplantation is, at least in part, linked to cell residence times, then greater benefit may be observed with transplants into infarcts associated with persistent coronary artery occlusion. © 2012 The Author(s)

    Knowledge and use of family planning among men in rural Uganda.

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    BACKGROUND: Unmet need for family planning exceeds 33% in Uganda. One approach to decreasing unmet need is promoting male involvement in family planning. Male disapproval of use of family planning by their female partners and misconceptions about side effects are barriers to family planning globally and in Uganda in particular. Researchers have conducted a number of qualitative studies in recent years to examine different aspects of family planning among Ugandan men. The present study aimed to quantify men's knowledge of family planning in rural Uganda to understand how better to involve men in couples' contraceptive decision-making, particularly in low-resource settings. METHODS: Data were derived from in-person, researcher-administered surveys of men in a rural agrarian district in Uganda (N = 178). Participant demographics and knowledge of family planning methods, side effects, and use were queried. Descriptive statistics were used for analysis. RESULTS: Men were 34 years of age on average (range 18-71) and about half (56%) had a primary school education or less. Ninety-eight percent reported any knowledge of family planning, with 73% of men reporting obtaining information via radio and only 43% from health workers. The most common method known by men was the male condom (72%), but more than half also knew of injections (54%) and pills (52%). Relatively few men reported knowing about the most effective reversible contraceptive methods, intrauterine devices and implants (both 16%). Men identified many common contraceptive side-effects, such as vaginal bleeding (31%), and misconceptions about side effects, such as increased risk of infertility and birth defects, were relatively uncommon (both < 10%). About half of all men reported ever using a family planning method (53%), and 40% reported current use. CONCLUSIONS: This study's quantitative results build on those of recent qualitative studies and provide information about the types of family planning information men are lacking and avenues for getting this information to them
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