2,764 research outputs found

    Studies in carboniferous bryozoa

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    Morphological investigations of some British Carboniferous bryozoan taxa has allowed aspects of their palaeobiology and systematics to be revised. Forty-one taxa, representing seventeen genera of nine families in the extinct Palaeozoic orders Cryptostomata, Fenestrate, Trepostomata and Cystoporata, are redescribed. Lectotypes have been established wherever necessary. Three new species are described and holotypes have been selected for these. Ordinal, familial and generic assignments have been made and diagnoses emended. Significant aspects of ordinal, familial and generic morphological characters have been discussed. Skeletal ultrastructures have been analysed in most forms studied and the function of a number of morphological characters has been reviewed. Evidence of the double walled concept of growth in the four extinct stenolaemate order have been reviewed. Extensive quantitative studies have allowed precise assessment of taxa, and the accurate definition and quantification of some unusual aspects of skeletal morphology, notably in Rhabdomeson rhombifera (Phillips). Combined with the quantitative studies there are extensive photographs and illustrations of the new and redescribed taxa. Geological ranges have been established for all taxa described

    Predicting sexual problems in women: The relevance of sexual excitation and sexual inhibition

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    This is the post-print version of the article. The official published version can be obtained from the link below.Data from a non-clinical sample of 540 heterosexual women were used to examine the relationships between scores on the Sexual Excitation/Sexual Inhibition Inventory for Women (SESII-W) and ratings of current sexual problems, lifetime arousal difficulty, lifetime orgasm difficulty, and lifetime problems with low sexual interest. Multiple regression analyses also included several demographic/background variables as predictors: age, full-time employment, completed college, children in household, married, health ratings, importance of sex, and whether the woman was in a sexual relationship. The strongest statistical predictors of both current and lifetime sexual problems were the SESII-W inhibition factors Arousal Contingency and Concerns about Sexual Function. Demographic factors did not feature largely in any of the models predicting sexual problems even when statistically significant relationships were found. If future research supports the predictive utility of the SESII-W in identifying women who are more likely to experience sexual difficulties, these scales may be used as prognostic factors in treatment studies.This study was funded, in part, by a grant from the Lilly Centre for Women's Health

    Extraction and measurement of adenosine triphosphate from marine sediment, The

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    Includes bibliographical references (pages 479-480).A technique has been developed, using boiling sodium bicarbonate buffer, to extract adenosine triphosphate (ATP) from marine sediments and has been tested on a variety of sediments, including those with high organic content, clay, and carbonate. Recovery of ATP, as measured by the addition of bacteria of known ATP content to sediment, varied from 64-100%. The technique also was as effective as the conventional Tris buffer for extraction of ATP from both pure cultures of bacteria grown in broth and natural seawater samples.Publisher version: http://www.jstor.org/stable/2835285

    Regional differences in lectin binding patterns of vestibular hair cells

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    Surface glycoconjugates of hair cells and supporting cells in the vestibular endorgans of the bullfrog were identified using biotinylated lectins with different carbohydrate specificities. Lectin binding in hair cells was consistent with the presence of glucose and mannose (CON A), galactose (RCA-I), N-acetylgalactosamine (VVA), but not fucose (UEA-I) residues. Hair cells in the bullfrog sacculus, unlike those in the utriculus and semicircular canals, did not stain for N-acetylglucosamine (WGA) or N-acetylgalactosamine (VVA). By contrast, WGA and, to a lesser extent, VVA, differentially stained utricular and semicircular canal hair cells, labeling hair cells located in peripheral, but not central, regions. In mammals, WGA uniformly labeled Type 1 hair cells while labeling, as in the bullfrog, Type 2 hair cells only in peripheral regions. These regional variations were retained after enzymatic digestion. We conclude that vestibular hair cells differ in their surface glycoconjugates and that differences in lectin binding patterns can be used to identify hair cell types and to infer the epithelial origin of isolated vestibular hair cells

    Scientific Visualization Using the Flow Analysis Software Toolkit (FAST)

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    Over the past few years the Flow Analysis Software Toolkit (FAST) has matured into a useful tool for visualizing and analyzing scientific data on high-performance graphics workstations. Originally designed for visualizing the results of fluid dynamics research, FAST has demonstrated its flexibility by being used in several other areas of scientific research. These research areas include earth and space sciences, acid rain and ozone modelling, and automotive design, just to name a few. This paper describes the current status of FAST, including the basic concepts, architecture, existing functionality and features, and some of the known applications for which FAST is being used. A few of the applications, by both NASA and non-NASA agencies, are outlined in more detail. Described in the Outlines are the goals of each visualization project, the techniques or 'tricks' used lo produce the desired results, and custom modifications to FAST, if any, done to further enhance the analysis. Some of the future directions for FAST are also described

    Dynamics of the magnetic and structural a -> e phase transition in Iron

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    We have studied the high-pressure iron bcc to hcp phase transition by simultaneous X-ray Magnetic Circular Dichroism (XMCD) and X-ray Absorption Spectroscopy (XAS) with an X-ray dispersive spectrometer. The combination of the two techniques allows us to obtain simultaneously information on both the structure and the magnetic state of Iron under pressure. The magnetic and structural transitions simultaneously observed are sharp. Both are of first order in agreement with theoretical prediction. The pressure domain of the transition observed (2.4 ±\pm 0.2 GPa) is narrower than that usually cited in the literature (8 GPa). Our data indicate that the magnetic transition slightly precedes the structural one, suggesting that the origin of the instability of the bcc phase in iron with increasing pressure is to be attributed to the effect of pressure on magnetism as predicted by spin-polarized full potential total energy calculations
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