1,175 research outputs found

    Effects of surface roughness on the intensity distribution of light reflected from aluminum surfaces

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    Only over the past few years have investigations of the intensity distribution of the light reflected from materials been attempted. Most of these investigations have been done by personnel at the National Bureau of Standards on matt surfaces, and acid etched black glass. It should be noted that separate investigations in the two fields, the methods of analysis of a surface\u27s topography and the intensity distribution of reflected light from different materials have been and still are being performed. However, most correlations which exist between a surface\u27s topography and its optical effects such as reflectance, intensity, absorption, and transmission are generally unknown. The purpose of this investigation is an attempt to correlate the roughness height and the intensity of the light reflected from 99.99% aluminum metal, hereafter simply referred to as aluminum metal, and to try to explain their meaning

    HIV-1 envelope protein gp41: An NMR study of dodecyl phosphocholine embedded gp41 reveals a dynamic prefusion intermediate conformation.

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    Human immunodeficiency viral (HIV-1) fusion is mediated by the viral envelope gp120/gp41 complex (ENVelope glycoprotein). After gp120 shedding, gp41 is exposed and elicits membrane fusion via a cascade of conformational changes. In contrast to prefusion and postfusion conformation, little is known about any intermediate conformation. We report on a solution NMR investigation of homotrimeric HIV-1 gp4127–194, comprising the transmembrane region and reconstituted in dodecyl phosphocholine (DPC) micelles. The protein is mainly α-helical, but experiences internal dynamics on the nanosecond and micro to millisecond time scale and transient α-helical behavior for certain residues in the N-terminal heptad repeat (NHR). Strong lipid interactions are observed, in particular for C-terminal residues of the NHR and imunodominant loop region connecting NHR and C-terminal heptad repeat (CHR). Our data indicate an extended conformation with features anticipated for a prefusion intermediate, presumably in exchange with a lowly populated postfusion six-helical bundle conformation

    Experimental chronic noise is related to elevated fecal corticosteroid metabolites in lekking male greater Sage-Grouse (Centrocercus urophasianus).

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    There is increasing evidence that individuals in many species avoid areas exposed to chronic anthropogenic noise, but the impact of noise on those who remain in these habitats is unclear. One potential impact is chronic physiological stress, which can affect disease resistance, survival and reproductive success. Previous studies have found evidence of elevated stress-related hormones (glucocorticoids) in wildlife exposed to human activities, but the impacts of noise alone are difficult to separate from confounding factors. Here we used an experimental playback study to isolate the impacts of noise from industrial activity (natural gas drilling and road noise) on glucocorticoid levels in greater sage-grouse (Centrocercus urophasianus), a species of conservation concern. We non-invasively measured immunoreactive corticosterone metabolites from fecal samples (FCMs) of males on both noise-treated and control leks (display grounds) in two breeding seasons. We found strong support for an impact of noise playback on stress levels, with 16.7% higher mean FCM levels in samples from noise leks compared with samples from paired control leks. Taken together with results from a previous study finding declines in male lek attendance in response to noise playbacks, these results suggest that chronic noise pollution can cause greater sage-grouse to avoid otherwise suitable habitat, and can cause elevated stress levels in the birds who remain in noisy areas

    Dietary macronutrient distribution influences post-exercise substrate utilization in women: A cross-sectional evaluation of metabolic flexibility

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    Metabolic flexibility is the ability to alter substrate utilization in response to substrate availability, which may influence health and performance. The current study evaluated the effects of habitual macronutrient distribution on energy expenditure (EE) and metabolic flexibility in physically active women

    Review of the quarter's economic trends [October 1981]

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    In the second quarter of 1981 the index of industrial production for the United Kingdom was 8% below its level for the corresponding period in 1980. This notwithstanding, there do appear to be signs that the bottom of the output trough may now have been reached. This brief section will seek to understand the latest UK and world economic data to determine current economic conditions and forecasts future trends

    Dothistroma septosporum identified in Greece on Pinus brutia and Pinus nigra plantations

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    No abstract available.http://apsjournals.apsnet.org/loi/pdishb201

    Tissue inhibitor of metalloproteinase-1 (TIMP-1) regulates mesenchymal stem cells through let-7f microRNA and Wnt/β-catenin signaling

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    Tissue inhibitor of metalloproteinases 1 (TIMP-1) is a matrix metalloproteinase (MMP)-independent regulator of growth and apoptosis in various cell types. The receptors and signaling pathways that are involved in the growth factor activities of TIMP-1, however, remain controversial. RNA interference of TIMP-1 has revealed that endogenous TIMP-1 suppresses the proliferation, metabolic activity, and osteogenic differentiation capacity of human mesenchymal stem cells (hMSCs). The knockdown of TIMP-1 in hMSCs activated the Wnt/β-catenin signaling pathway as indicated by the increased stability and nuclear localization of β-catenin in TIMP-1–deficient hMSCs. Moreover, TIMP-1 knockdown cells exhibited enhanced β-catenin transcriptional activity, determined by Wnt/β-catenin target gene expression analysis and a luciferase-based β-catenin– activated reporter assay. An analysis of a mutant form of TIMP-1 that cannot inhibit MMP indicated that the effect of TIMP-1 on β-catenin signaling is MMP independent. Furthermore, the binding of CD63 to TIMP-1 on the surface of hMSCs is essential for the TIMP-1–mediated effects on Wnt/β-catenin signaling. An array analysis of microRNAs (miRNAs) and transfection studies with specific miRNA inhibitors and mimics showed that let-7f miRNA is crucial for the regulation of β-catenin activity and osteogenic differentiation by TIMP-1. Let-7f was up-regulated in TIMP-1–depleted hMSCs and demonstrably reduced axin 2, an antagonist of β-catenin stability. Our results demonstrate that TIMP-1 is a direct regulator of hMSC functions and reveal a regulatory network in which let-7f modulates Wnt/β-catenin activity

    High-intensity interval training: Modulating interval duration in overweight/obese men

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    High-intensity interval training (HIIT) is a time-efficient strategy shown to induce various cardiovascular and metabolic adaptations. Little is known about the optimal tolerable combination of intensity and volume necessary for adaptations, especially in clinical populations

    Summary [January 1978]

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    This brief provides a summary of the world, UK and Scottish economic outlook. The upward movement in the Scotland/UK unemployment relative over the past few quarters is unlikely to portend a return to the poor relative performance of the Scottish economy which occurred in the early nineteen sixties. Nevertheless the outlook for the Scottish economy in 1978 is not very encouraging
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