40 research outputs found

    Effects of an irregular bedtime schedule on sleep quality, daytime sleepiness, and fatigue among university students in Taiwan

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    <p>Abstract</p> <p>Background</p> <p>An irregular bedtime schedule is a prevalent problem in young adults, and could be a factor detrimentally affecting sleep quality. The goal of the present study was to explore the association between an irregular bedtime schedule and sleep quality, daytime sleepiness, and fatigue among undergraduate students in Taiwan.</p> <p>Methods</p> <p>A total of 160 students underwent a semi-structured interview and completed a survey comprising 4 parts: Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Fatigue Severity Scale (FSS), and a rating of irregular bedtime frequency. Participants were grouped into 3 groups in terms of irregular bedtime frequency: low, intermediate, or high according to their 2-week sleep log. To screen for psychological disorders or distress that may have affected responses on the sleep assessment measures, the Chinese health questionnaire-12 (CHQ-12) was also administered.</p> <p>Results</p> <p>We found an increase in bedtime schedule irregularity to be significantly associated with a decrease in average sleep time per day (Spearman r = -0.22, p = 0.05). Multivariate regression analysis revealed that irregular bedtime frequency and average sleep time per day were correlated with PSQI scores, but not with ESS or FSS scores. A significant positive correlation between irregular bedtime frequency and PSQI scores was evident in the intermediate (partial r = 0.18, p = 0.02) and high (partial r = 0.15, p = 0.05) frequency groups as compared to low frequency group.</p> <p>Conclusion</p> <p>The results of our study suggest a high prevalence of both an irregular bedtime schedule and insufficient sleep among university students in Taiwan. Students with an irregular bedtime schedule may experience poor sleep quality. We suggest further research that explores the mechanisms involved in an irregular bedtime schedule and the effectiveness of interventions for improving this condition.</p

    Shaping public opinion on the issue of childbirth; a critical analysis of articles published in an Australian newspaper

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    <p>Abstract</p> <p>Background</p> <p>The Australian government has announced a major program of reform with the move to primary maternity care, a program of change that appears to be at odds with current general public perceptions regarding how maternity care is delivered.</p> <p>Methods</p> <p>A critical discourse analysis of articles published in 'The Age', a newspaper with national distribution, subsequent to the release of the discussion paper by the Australian Government in 2008 was undertaken. The purpose was to identify how Australian maternity services are portrayed and what purpose is served by this representation to the general public.</p> <p>Results</p> <p>Findings from this critical discourse analysis revealed that Australian maternity services are being portrayed to the general public as an inflexible outdated service struggling to meets the needs of pregnant women and in desperate need of reform. The style of reporting employed in this newspaper involved presenting to the reader the range of expert opinion relevant to each topic, frequently involving polarised positions of the experts on the issue.</p> <p>Conclusions</p> <p>The general public are presented with a conflict, caught between the need for changes that come with the primary maternity model of care and fear that these change will undermine safe standards. The discourse; 'Australia is one of the safest countries in which to give birth or be born, what is must be best', represents the situation where despite major deficiencies in the system the general public may be too fearful of the consequences to consider a move away from reliance on traditional medical-led maternity care.</p

    Brevenal Inhibits Pacific Ciguatoxin-1B-Induced Neurosecretion from Bovine Chromaffin Cells

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    Ciguatoxins and brevetoxins are neurotoxic cyclic polyether compounds produced by dinoflagellates, which are responsible for ciguatera and neurotoxic shellfish poisoning (NSP) respectively. Recently, brevenal, a natural compound was found to specifically inhibit brevetoxin action and to have a beneficial effect in NSP. Considering that brevetoxin and ciguatoxin specifically activate voltage-sensitive Na+ channels through the same binding site, brevenal has therefore a good potential for the treatment of ciguatera. Pacific ciguatoxin-1B (P-CTX-1B) activates voltage-sensitive Na+ channels and promotes an increase in neurotransmitter release believed to underpin the symptoms associated with ciguatera. However, the mechanism through which slow Na+ influx promotes neurosecretion is not fully understood. In the present study, we used chromaffin cells as a model to reconstitute the sequence of events culminating in ciguatoxin-evoked neurosecretion. We show that P-CTX-1B induces a tetrodotoxin-sensitive rise in intracellular Na+, closely followed by an increase in cytosolic Ca2+ responsible for promoting SNARE-dependent catecholamine secretion. Our results reveal that brevenal and β-naphtoyl-brevetoxin prevent P-CTX-1B secretagogue activity without affecting nicotine or barium-induced catecholamine secretion. Brevenal is therefore a potent inhibitor of ciguatoxin-induced neurotoxic effect and a potential treatment for ciguatera

    National review of maternity services 2008: women influencing change

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    <p>Abstract</p> <p>Background</p> <p>In 2009 the Australian government announced a major program of reform with the move to primary maternity care. The reform agenda represents a dramatic change to maternity care provision in a society that has embraced technology across all aspects of life including childbirth.</p> <p>Methods</p> <p>A critical discourse analysis of selected submissions in the consultation process to the national review of maternity services 2008 was undertaken to identify the contributions of individual women, consumer groups and organisations representing the interests of women.</p> <p>Results</p> <p>Findings from this critical discourse analysis revealed extensive similarities between the discourses identified in the submissions with the direction of the 2009 proposed primary maternity care reform agenda. The rise of consumer influence in maternity care policy reflects a changing of the guard as doctors' traditional authority is questioned by strong consumer organisations and informed consumers.</p> <p>Conclusions</p> <p>Unified consumer influence advocating a move away from obstetric -led maternity care for all pregnant women appears to be synergistic with the ethos of corporate governance and a neoliberal approach to maternity service policy. The silent voice of one consumer group (women happy with their obstetric-led care) in the consultation process has inadvertently contributed to a consensus of opinion in support of the reforms in the absence of the counter viewpoint.</p

    A Novel Protein Kinase-Like Domain in a Selenoprotein, Widespread in the Tree of Life

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    Selenoproteins serve important functions in many organisms, usually providing essential oxidoreductase enzymatic activity, often for defense against toxic xenobiotic substances. Most eukaryotic genomes possess a small number of these proteins, usually not more than 20. Selenoproteins belong to various structural classes, often related to oxidoreductase function, yet a few of them are completely uncharacterised

    The distribution and purity of anorthosite across the Orientale basin: New perspectives from Moon Mineralogy Mapper data

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    The Orientale basin is a multiring impact structure on the western limb of the Moon that provides a clear view of the primary lunar crust exposed during basin formation. Previously, near‐infrared reflectance spectra suggested that Orientale's Inner Rook Ring (IRR) is very poor in mafic minerals and may represent anorthosite excavated from the Moon's upper crust. However, detailed assessment of the mineralogy of these anorthosites was prohibited because the available spectroscopic data sets did not identify the diagnostic plagioclase absorption feature near 1250 nm. Recently, however, this absorption has been identified in several spectroscopic data sets, including the Moon Mineralogy Mapper (M3), enabling the unique identification of a plagioclase‐dominated lithology at Orientale for the first time. Here we present the first in‐depth characterization of the Orientale anorthosites based on direct measurement of their plagioclase component. In addition, detailed geologic context of the exposures is discussed based on analysis of Lunar Reconnaissance Orbiter Narrow Angle Camera images for selected anorthosite identifications. The results confirm that anorthosite is overwhelmingly concentrated in the IRR. Comparison with nonlinear spectral mixing models suggests that the anorthosite is exceedingly pure, containing >95 vol % plagioclase in most areas and commonly ~99–100 vol %. These new data place important constraints on magma ocean crystallization scenarios, which must produce a zone of highly pure anorthosite spanning the entire lateral extent of the 430 km diameter IRR. </p

    The distribution and purity of anorthosite across the Orientale basin: New perspectives from Moon Mineralogy Mapper data

    No full text
    The Orientale basin is a multiring impact structure on the western limb of the Moon that provides a clear view of the primary lunar crust exposed during basin formation. Previously, near‐infrared reflectance spectra suggested that Orientale's Inner Rook Ring (IRR) is very poor in mafic minerals and may represent anorthosite excavated from the Moon's upper crust. However, detailed assessment of the mineralogy of these anorthosites was prohibited because the available spectroscopic data sets did not identify the diagnostic plagioclase absorption feature near 1250 nm. Recently, however, this absorption has been identified in several spectroscopic data sets, including the Moon Mineralogy Mapper (M3), enabling the unique identification of a plagioclase‐dominated lithology at Orientale for the first time. Here we present the first in‐depth characterization of the Orientale anorthosites based on direct measurement of their plagioclase component. In addition, detailed geologic context of the exposures is discussed based on analysis of Lunar Reconnaissance Orbiter Narrow Angle Camera images for selected anorthosite identifications. The results confirm that anorthosite is overwhelmingly concentrated in the IRR. Comparison with nonlinear spectral mixing models suggests that the anorthosite is exceedingly pure, containing &gt;95 vol % plagioclase in most areas and commonly ~99–100 vol %. These new data place important constraints on magma ocean crystallization scenarios, which must produce a zone of highly pure anorthosite spanning the entire lateral extent of the 430 km diameter IRR. </p

    Global assessment of pure crystalline plagioclase across the Moon and implications for the evolution of the primary crust

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    Recent advancements in visible to near infrared orbital measurements of the lunar surface have allowed the character and extent of the primary anorthositic crust to be studied at unprecedented spatial and spectral resolutions. Here we assess the lunar primary anorthositic crust in global context using a spectral parameter tool for Moon Mineralogy Mapper data to identify and map Fe‐bearing crystalline plagioclase based on its diagnostic 1.25 µm absorption band. This allows plagioclase‐dominated rocks, specifically anorthosites, to be unambiguously identified as well as distinguished from lithologies with minor to trace amounts of mafic minerals. Low spatial resolution global mosaics and high spatial resolution individual data strips covering more than 650 targeted craters were analyzed to identify and map the mineralogy of spectrally pure regions as small as ~400 m in size. Spectrally, pure plagioclase is identified in approximately 450 targets located across the lunar surface. Diviner thermal infrared (TIR) data are analyzed for 37 of these nearly monomineralic regions in order to understand the compositional variability of plagioclase (An#) in these areas. The average An# for each spectrally pure region is estimated using new laboratory measurements of a well‐characterized anorthite (An96) sample. Diviner TIR results suggest that the plagioclase composition across the lunar highlands is relatively uniform, high in calcium content, and consistent with plagioclase compositions found in the ferroan anorthosites (An94–98). Our results confirm that spectrally pure anorthosite is widely distributed across the lunar surface, and most exposures of the ancient anorthositic crust are concentrated in regions of thicker crust surrounding impact basins on the lunar nearside and farside. In addition, the scale of the impact basins and the global nature and distribution of pure plagioclase requires a coherent zone of anorthosite of similar composition in the lunar crust supporting its formation from a single differentiation event like a magma ocean. Our identifications of pure anorthosite combined with the GRAIL crustal thickness model suggest that pure anorthosite is currently observed at a range of crustal thickness values between 9 and 63 km and that the primary anorthositic crust must have been at least 30 km thick. </p

    Global assessment of pure crystalline plagioclase across the Moon and implications for the evolution of the primary crust

    No full text
    Recent advancements in visible to near infrared orbital measurements of the lunar surface have allowed the character and extent of the primary anorthositic crust to be studied at unprecedented spatial and spectral resolutions. Here we assess the lunar primary anorthositic crust in global context using a spectral parameter tool for Moon Mineralogy Mapper data to identify and map Fe‐bearing crystalline plagioclase based on its diagnostic 1.25 µm absorption band. This allows plagioclase‐dominated rocks, specifically anorthosites, to be unambiguously identified as well as distinguished from lithologies with minor to trace amounts of mafic minerals. Low spatial resolution global mosaics and high spatial resolution individual data strips covering more than 650 targeted craters were analyzed to identify and map the mineralogy of spectrally pure regions as small as ~400 m in size. Spectrally, pure plagioclase is identified in approximately 450 targets located across the lunar surface. Diviner thermal infrared (TIR) data are analyzed for 37 of these nearly monomineralic regions in order to understand the compositional variability of plagioclase (An#) in these areas. The average An# for each spectrally pure region is estimated using new laboratory measurements of a well‐characterized anorthite (An96) sample. Diviner TIR results suggest that the plagioclase composition across the lunar highlands is relatively uniform, high in calcium content, and consistent with plagioclase compositions found in the ferroan anorthosites (An94–98). Our results confirm that spectrally pure anorthosite is widely distributed across the lunar surface, and most exposures of the ancient anorthositic crust are concentrated in regions of thicker crust surrounding impact basins on the lunar nearside and farside. In addition, the scale of the impact basins and the global nature and distribution of pure plagioclase requires a coherent zone of anorthosite of similar composition in the lunar crust supporting its formation from a single differentiation event like a magma ocean. Our identifications of pure anorthosite combined with the GRAIL crustal thickness model suggest that pure anorthosite is currently observed at a range of crustal thickness values between 9 and 63 km and that the primary anorthositic crust must have been at least 30 km thick. </p
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