1,392 research outputs found

    Adult nutrition and butterfly fitness: effects of diet quality on reproductive output, egg composition, and egg hatching success

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    <p>Abstract</p> <p>Background</p> <p>In the Lepidoptera it was historically believed that adult butterflies rely primarily on larval-derived nutrients for reproduction and somatic maintenance. However, recent studies highlight the complex interactions between storage reserves and adult income, and that the latter may contribute significantly to reproduction. Effects of adult diet were commonly assessed by determining the number and/or size of the eggs produced, whilst its consequences for egg composition and offspring viability were largely neglected (as is generally true for insects). We here specifically focus on these latter issues by using the fruit-feeding tropical butterfly <it>Bicyclus anynana</it>, which is highly dependent on adult-derived carbohydrates for reproduction.</p> <p>Results</p> <p>Adult diet of female <it>B. anynana </it>had pronounced effects on fecundity, egg composition and egg hatching success, with butterflies feeding on the complex nutrition of banana fruit performing best. Adding vitamins and minerals to a sucrose-based diet increased fecundity, but not offspring viability. All other groups (plain sucrose solution, sucrose solution enriched with lipids or yeast) had a substantially lower fecundity and egg hatching success compared to the banana group. Differences were particularly pronounced later in life, presumably indicating the depletion of essential nutrients in sucrose-fed females. Effects of adult diet on egg composition were not straightforward, indicating complex interactions among specific compounds. There was some evidence that total egg energy and water content were related to hatching success, while egg protein, lipid, glycogen and free carbohydrate content did not seem to limit successful development.</p> <p>Conclusion</p> <p>The patterns shown here exemplify the complexity of reproductive resource allocation in <it>B. anynana</it>, and the need to consider egg composition and offspring viability when trying to estimate the effects of adult nutrition on fitness in this butterfly and other insects.</p

    Rapid testing leads to the underestimation of the scrapie prevalence in an affected sheep and goat flock

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    To obtain a more detailed understanding of the prevalence of classical scrapie infections in a heavily affected German sheep flock (composed of 603 sheep and 6 goats), we analysed 169 sheep and 6 goats that carried the genotypes susceptible to the disease and that were therefore culled following discovery of the index case. The initial tests were performed using the Biorad TeSeE ELISA and reactive results were verified by official confirmatory methods (OIE-immunoblot and/or immunohistochemistry (IHC)) to demonstrate the deposition of scrapie-associated PrPSc in the brain stem (obex). This approach led to the discovery of 40 additional subclinically scrapie-infected sheep. Furthermore, peripheral lymphatic and nervous tissue samples of the 129 sheep and 6 goats with a negative CNS result were examined by IHC in order to identify any preclinical infections which had not already spread to the central nervous system (CNS). Using this approach we found 13 additional sheep with PrPSc depositions in the gut-associated lymph nodes (GALT) as well as in the enteric nervous system. Moreover, in most of these cases PrPSc was also deposited in the spleen and in the retropharyngeal and superficial cervical lymph nodes. Taken together, these results show a 30.3% infection prevalence in this scrapie-affected flock. Almost 7.4% of the infected animals harboured PrPSc exclusively in the peripheral lymphatic and nervous tissue and were therefore missed by the currently used testing strategy

    The co-evolution of total density profiles and central dark matter fractions in simulated early-type galaxies

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    We present evidence from cosmological hydrodynamical simulations for a co-evolution of the slope of the total (dark and stellar) mass density profile, gamma (tot), and the dark matter fraction within the half-mass radius, f(DM), in early-type galaxies. The relation can be described as gamma(tot) = A f(DM) + B for all systems at all redshifts. The trend is set by the decreasing importance of gas dissipation towards lower redshifts and for more massive systems. Early-type galaxies are smaller, more concentrated, have lower f(DM) and steeper gamma(tot) at high redshifts and at lower masses for a given redshift; f(DM) and gamma(tot) are good indicators for growth by 'dry' merging. The values for A and B change distinctively for different feedback models, and this relation can be used as a test for such models. A similar correlation exists between gamma(tot) and the stellar mass surface density Sigma(*). A model with weak stellar feedback and feedback from black holes is in best agreement with observations. All simulations, independent of the assumed feedback model, predict steeper gamma(tot) and lower f(DM) at higher redshifts. While the latter is in agreement with the observed trends, the former is in conflict with lensing observations, which indicate constant or decreasing gamma(tot). This discrepancy is shown to be artificial: the observed trends can be reproduced from the simulations using observational methodology to calculate the total density slopes.Peer reviewe

    Protection against ultraviolet radiation by commercial summer clothing: need for standardised testing and labelling

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    BACKGROUND: The use of clothing as a means of sun protection has been recommended in recent education campaigns. Contrary to popular opinion, however, some fabrics provide insufficient ultraviolet (UV) protection. MATERIAL AND METHODS: We investigated 236 apparel textiles of the spring/summer collections 2000 and 2001. In accordance with the forthcoming European standard the UV protection factor (UPF) of the fabrics was determined spectrophotometrically. RESULTS: Seventy-eight (33%) fabrics had UPF < 15, 45 (19%) had UPF = or > 15 and < 30, and 113 (48%) had UPF = or > 30 (30+). More than 70% of the wool, polyester, and fabric blends, and only less than 30% of the cotton, linen, and viscose fabrics had UPF values of 30+. Fabrics with black, navy-blue, white, green, or beige colours provided most frequently UPF values of 30+. CONCLUSIONS: It is difficult for the sun-aware consumer to choose the 'right' garment, with a third of summer clothing providing insufficient UV protection and only half of the fabrics having UPF 30+, the UPF recommended by the European standard. Therefore, apparel summer fabrics should be measured and labelled in accordance with a standard document

    Volumizing effects of a smooth, highly cohesive, viscous 20-mg/mL hyaluronic acid volumizing filler: prospective European study

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    <p>Abstract</p> <p>Background</p> <p>Facial volume loss contributes significantly to facial aging. The 20-mg/mL hyaluronic acid (HA) formulation used in this study is a smooth, highly cohesive, viscous, fully reversible, volumizing filler indicated to restore facial volume. This first prospective study evaluated use in current aesthetic clinical practice.</p> <p>Methods</p> <p>A pan-European evaluation conducted under guidelines of the World Association of Opinion and Marketing Research, the trial comprised a baseline visit (visit 1) and a follow-up (visit 2) at 14 ± 7 days posttreatment. Physicians photographed patients at each visit. Each patient was treated with the 20-mg/mL HA volumizing filler as supplied in standard packaging. Procedural details, aesthetic outcomes, safety, and physician and patient ratings of their experience were recorded.</p> <p>Results</p> <p>Fifteen physicians and 70 patients (91% female; mean age: 50 years) participated. Mean volume loss at baseline was 3.7 (moderate) on the Facial Volume Loss Scale. Local anesthesia was used in 64.3% of cases. Most injections (85%) were administered with needles rather than cannulas. Of the 208 injections, 59% were in the malar region, primarily above the periosteum. Subcutaneous injections were most common for other sites. The mean total injection volume per patient was 4.6 mL. The mean volume loss score declined significantly (<it>P </it>< .001) to 2.1 at visit 2. On the Global Aesthetic Improvement Scale, 88% and 76% of the treatments were rated very much improved or much improved by physicians and patients, respectively. Of the physicians, 95.6% rated this HA filler as very or fairly easy to use. Similarly, 92% of patients were very likely or quite likely to return for treatment; nearly all (98%) would recommend this treatment to friends. Transient (mean duration: 5.5 days) injection-site adverse events (AEs) occurred in 24 patients. Bruising was the most common AE.</p> <p>Conclusion</p> <p>The 20-mg/mL smooth, highly cohesive, viscous, volumizing HA filler was effective, well tolerated, and easy to use in current clinical practice. Participants were very likely to recommend this product to colleagues and friends, and patients would be very or quite likely to request this product for future treatments.</p

    Возможность использования высокочастотного CuBr-лазера для создания скоростного лазерного монитора

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    Представлены оценки максимальных температур источников как внешней, так и собственной засветки, при которых будут иметь место искажения изображений, формируемых посредствам активных оптических систем. Показана возможность использования высокочастотного CuBr-лазера в качестве усилителя яркости лазерного монитора
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