2,257 research outputs found

    SGAME Simulations of the [CII], [OI], and [OIII] Line Emission from Star-forming Galaxies at zâ‰Č 6

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    Of the almost 40 star-forming galaxies at z ≄ 5 (not counting quasi-stellar objects) observed in [C II ] to date, nearly half are either very faint in [C II ] or not detected at all, and fall well below expectations based on locally derived relations between star formation rate and [C II ] luminosity. This has raised questions as to how reliable [C II ] is as a tracer of star formation activity at these epochs and how factors such as metallicity might affect the [C II ] emission. Combining cosmological zoom simulations of galaxies with SGAME (SImulator of GAlaxy Millimeter/ submillimeter Emission), we modeled the multiphased interstellar medium (ISM) and its emission in [C II ] , as well as in [O I ] and [O III ], from 30 main-sequence galaxies at z â‰Č6 with star formation rates ∌323 M· yr -1 , stellar masses ∌ 0.7 8 109 M·, and metallicities ∌ 0.1 0.4 Z?. The simulations are able to reproduce the aforementioned [C II ] faintness of some normal star-forming galaxy sources at z 5. In terms of [O I ] and [O III ], very few observations are available at z 5, but our simulations match two of the three existing z 5 detections of [O III ] and are furthermore roughly consistent with the [O I ] and [O III ] luminosity relations with star formation rate observed for local starburst galaxies. We find that the [C II ] emission is dominated by the diffuse ionized gas phase and molecular clouds, which on average contribute ∌66% and ∌27%, respectively. The molecular gas, which constitutes only ∌10% of the total gas mass, is thus a more efficient emitter of [C II ] than the ionized gas, which makes up ∌85% of the total gas mass. A principal component analysis shows that the [C II ] luminosity correlates with the star formation activity of a galaxy as well as its average metallicity. The low metallicities of our simulations together with their low molecular gas mass fractions can account for their [C II ] faintness, and we suggest that these factors may also be responsible for the [C II ] -faint normal galaxies observed at these early epochs

    Histological analysis of low dose NMU effects in the rat mammary gland

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    <p>Abstract</p> <p>Background</p> <p>Our objective was to assess the histological changes in mammary glands of the female Wistar-Furth rat as a result of low dose exposure to N-nitrosomethylurea (NMU).</p> <p>Methods</p> <p>Groups of 30–40 virgin female rats of between 49–58 days old received a single injection of 10, 20, 30 or 50 mg NMU/kg body weight (BW). A group of 10 control rats received 0.9% NaCl solution only. The formation of palpable mammary gland tumors was assessed weekly and, upon sacrifice at 12, 22 and 25–30 weeks after treatment, we performed a comprehensive histological analysis of all mammary gland lesions and tumors.</p> <p>Results</p> <p>Alongside the predicted increase in tumor number and decrease in tumor latency with increasing NMU dose, we observed a number of microscopic lesions and other epithelial abnormalities in the mammary glands for all NMU doses. Two types of non-neoplastic histological changes were observed in rats exposed to 10 or 20 mg NMU/kg BW: namely, (i) an increase in the number of acinar structures often accompanied by secretion into the lumen which is normally associated with pregnancy and lactation, and (ii) an increase in the number of epithelial cells sloughed into the lumen of the epithelial ducts.</p> <p>Conclusion</p> <p>This study establishes a baseline for low-dose exposure and defines the histological features in the mammary gland resulting from NMU exposure. Furthermore, this system provides an ideal platform for evaluating the relative susceptibility of animals protected from, or predisposed to, developing cancer through environmental influences.</p

    An organizing framework for informal caregiver interventions: detailing caregiving activities and caregiver and care recipient outcomes to optimize evaluation efforts

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    Abstract Background Caregiver interventions may help improve the quality of informal care. Yet the lack of a systematic framework specifying the targets and outcomes of caregiver interventions hampers our ability to understand what has been studied, to evaluate existing programs, and to inform the design of future programs. Our goal was to develop an organizing framework detailing the components of the caregiving activities and the caregiver and care recipient outcomes that should be affected by an intervention. In so doing, we characterize what has been measured in the published literature to date and what should be measured in future studies to enable comparisons across interventions and across time. Methods Our data set comprises 121 reports of caregiver interventions conducted in the United States and published between 2000 and 2009. We extracted information on variables that have been examined as primary and secondary outcomes. These variables were grouped into categories, which then informed the organizing framework. We calculated the frequency with which the interventions examined each framework component to identify areas about which we have the most knowledge and under-studied areas that deserve attention in future research. Results The framework stipulates that caregiver interventions seek to change caregiving activities, which in turn affect caregiver and care recipient outcomes. The most frequently assessed variables have been caregiver psychological outcomes (especially depression and burden) and care recipient physical and health care use outcomes. Conclusions Based on the organizing framework, we make three key recommendations to guide interventions and inform research and policy. First, all intervention studies should assess quality and/or quantity of caregiving activities to help understand to what extent and how well the intervention worked. Second, intervention studies should assess a broad range of caregiver and care recipient outcomes, including considering whether expanding to economic status and health care use of the caregiver can be accommodated, to ease subsequent economic evaluations of caregiving. Third, intervention studies should measure a common set of outcomes to facilitate cross-time and cross-study comparisons of effectiveness

    Mapping interactions with the chaperone network reveals factors that protect against tau aggregation.

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    A network of molecular chaperones is known to bind proteins ('clients') and balance their folding, function and turnover. However, it is often unclear which chaperones are critical for selective recognition of individual clients. It is also not clear why these key chaperones might fail in protein-aggregation diseases. Here, we utilized human microtubule-associated protein tau (MAPT or tau) as a model client to survey interactions between ~30 purified chaperones and ~20 disease-associated tau variants (~600 combinations). From this large-scale analysis, we identified human DnaJA2 as an unexpected, but potent, inhibitor of tau aggregation. DnaJA2 levels were correlated with tau pathology in human brains, supporting the idea that it is an important regulator of tau homeostasis. Of note, we found that some disease-associated tau variants were relatively immune to interactions with chaperones, suggesting a model in which avoiding physical recognition by chaperone networks may contribute to disease

    Current status of 5α-reductase inhibitors in the management of lower urinary tract symptoms and BPH

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    Benign prostatic hyperplasia (BPH) is a progressive disease that is commonly associated with bothersome lower urinary tract symptoms (LUTS) and might result in complications, such as acute urinary retention and BPH-related surgery. Therefore, the goals of therapy for BPH are not only to improve LUTS in terms of symptoms and urinary flow, but also to identify those patients at a risk of unfavorable disease progression and to optimize their management. This article reviews the current status of therapy with 5 alpha-reductase inhibitors (5ARIs), namely fiasteride and dutasteride, for men with LUTS and BPH. Data from key randomized controlled trials (Oxford level 1b) on the use of 5ARIs are analyzed. The efficacy of 5ARIs either as monotherapy or in combination with alpha(1)-adrenoceptor antagonists in the management of LUTS and the impact of monotherapy and combined therapy on BPH progression are discussed. Further promises, including the withdrawal of the alpha-blocker from the combined medical treatment and the potential clinical implications from the use of 5ARIs for prostate cancer chemoprevention in patients receiving 5ARIs for symptomatic BPH are highlighted. Current evidence shows that 5ARIs are effective in treating LUTS and preventing disease progression and represent a recommended option in treatment guidelines for men who have moderate to severe LUTS and enlarged prostates

    Hard Superconductivity of a Soft Metal in the Quantum Regime

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    Superconductivity is inevitably suppressed in reduced dimensionality. Questions of how thin superconducting wires or films can be before they lose their superconducting properties have important technological ramifications and go to the heart of understanding coherence and robustness of the superconducting state in quantum-confined geometries. Here, we exploit quantum confinement of itinerant electrons in a soft metal to stabilize superconductors with lateral dimensions of the order of a few millimeters and vertical dimensions of only a few atomic layers. These extremely thin superconductors show no indication of defect- or fluctuation-driven suppression of superconductivity and sustain supercurrents of up to 10% of the depairing current density. The extreme hardness of the critical state is attributed to quantum trapping of vortices. This study paints a conceptually appealing, elegant picture of a model nanoscale superconductor with calculable critical state properties. It indicates the intriguing possibility of exploiting robust superconductivity at the nanoscale.Comment: 15 pages, 4 figures, submitted to Nature Physic

    A cross-national study on the antecedents of work–life balance from the fit and balance perspective

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    Drawing on the perceived work–family fit and balance perspective, this study investigates demands and resources as antecedents of work–life balance (WLB) across four countries (New Zealand, France, Italy and Spain), so as to provide empirical cross-national evidence. Using structural equation modelling analysis on a sample of 870 full time employees, we found that work demands, hours worked and family demands were negatively related to WLB, while job autonomy and supervisor support were positively related to WLB. We also found evidence that resources (job autonomy and supervisor support) moderated the relationships between demands and work–life balance, with high resources consistently buffering any detrimental influence of demands on WLB. Furthermore, our study identified additional predictors of WLB that were unique to some national contexts. For example, in France and Italy, overtime hours worked were negatively associated with WLB, while parental status was positively associated with WLB. Overall, the implications for theory and practice are discussed.Peer ReviewedPostprint (author's final draft

    Molecular characterisation of protist parasites in human-habituated mountain gorillas (Gorilla beringei beringei), humans and livestock, from Bwindi impenetrable National Park, Uganda

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    Over 60 % of human emerging infectious diseases are zoonotic, and there is growing evidence of the zooanthroponotic transmission of diseases from humans to livestock and wildlife species, with major implications for public health, economics, and conservation. Zooanthroponoses are of relevance to critically endangered species; amongst these is the mountain gorilla (Gorilla beringei beringei) of Uganda. Here, we assess the occurrence of Cryptosporidium, Cyclospora, Giardia, and Entamoeba infecting mountain gorillas in the Bwindi Impenetrable National Park (BINP), Uganda, using molecular methods. We also assess the occurrence of these parasites in humans and livestock species living in overlapping/adjacent geographical regions

    The First Sequenced Carnivore Genome Shows Complex Host-Endogenous Retrovirus Relationships

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    Host-retrovirus interactions influence the genomic landscape and have contributed substantially to mammalian genome evolution. To gain further insights, we analyzed a female boxer (Canis familiaris) genome for complexity and integration pattern of canine endogenous retroviruses (CfERV). Intriguingly, the first such in-depth analysis of a carnivore species identified 407 CfERV proviruses that represent only 0.15% of the dog genome. In comparison, the same detection criteria identified about six times more HERV proviruses in the human genome that has been estimated to contain a total of 8% retroviral DNA including solitary LTRs. These observed differences in man and dog are likely due to different mechanisms to purge, restrict and protect their genomes against retroviruses. A novel group of gammaretrovirus-like CfERV with high similarity to HERV-Fc1 was found to have potential for active retrotransposition and possibly lateral transmissions between dog and human as a result of close interactions during at least 10.000 years. The CfERV integration landscape showed a non-uniform intra- and inter-chromosomal distribution. Like in other species, different densities of ERVs were observed. Some chromosomal regions were essentially devoid of CfERVs whereas other regions had large numbers of integrations in agreement with distinct selective pressures at different loci. Most CfERVs were integrated in antisense orientation within 100 kb from annotated protein-coding genes. This integration pattern provides evidence for selection against CfERVs in sense orientation relative to chromosomal genes. In conclusion, this ERV analysis of the first carnivorous species supports the notion that different mammals interact distinctively with endogenous retroviruses and suggests that retroviral lateral transmissions between dog and human may have occurred
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