2,608 research outputs found

    The Chandra XBootes Survey - III: Optical and Near-IR Counterparts

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    The XBootes Survey is a 5-ks Chandra survey of the Bootes Field of the NOAO Deep Wide-Field Survey (NDWFS). This survey is unique in that it is the largest (9.3 deg^2), contiguous region imaged in X-ray with complementary deep optical and near-IR observations. We present a catalog of the optical counterparts to the 3,213 X-ray point sources detected in the XBootes survey. Using a Bayesian identification scheme, we successfully identified optical counterparts for 98% of the X-ray point sources. The optical colors suggest that the optically detected galaxies are a combination of z<1 massive early-type galaxies and bluer star-forming galaxies whose optical AGN emission is faint or obscured, whereas the majority of the optically detected point sources are likely quasars over a large redshift range. Our large area, X-ray bright, optically deep survey enables us to select a large sub-sample of sources (773) with high X-ray to optical flux ratios (f_x/f_o>10). These objects are likely high redshift and/or dust obscured AGN. These sources have generally harder X-ray spectra than sources with 0.1<f_x/f_o<10. Of the 73 X-ray sources with no optical counterpart in the NDWFS catalog, 47 are truly optically blank down to R~25.5 (the average 50% completeness limit of the NDWFS R-band catalogs). These sources are also likely to be high redshift and/or dust obscured AGN.Comment: 19 pages, 13 figures, ApJ accepted. Catalog can be found at: http://www.noao.edu/noao/noaodeep or ftp://archive.noao.edu/pub/catalogs/xbootes

    The Truncated Disk of CoKu Tau/4

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    We present a model of a dusty disk with an inner hole which accounts for the Spitzer Space Telescope Infrared Spectrograph observations of the low-mass pre-main sequence star CoKu Tau/4. We have modeled the mid-IR spectrum (between 8 and 25 mic) as arising from the inner wall of a disk. Our model disk has an evacuated inner zone of radius ~ 10 AU, with a dusty inner ``wall'', of half-height ~ 2 AU, that is illuminated at normal incidence by the central star. The radiative equilibrium temperature decreases from the inner disk edge outward through the optically-thick disk; this temperature gradient is responsible for the emission of the silicate bands at 10 and 20 mic. The observed spectrum is consistent with being produced by Fe-Mg amorphous glassy olivine and/or pyroxene, with no evidence of a crystalline component. The mid-infrared spectrum of CoKu Tau/4 is reminiscent of that of the much older star TW Hya, where it has been suggested that the significant clearing of its inner disk is due to planet formation. However, no inner disk remains in CoKu Tau/4, consistent with the star being a weak-emission (non-accreting) T Tauri star. The relative youth of CoKu Tau/4 (~ 1 Myr) may indicate much more rapid planet formation than typically assumed.Comment: 32 pages, 9 figures, accepted in Ap

    Leg disorders in broiler chickens : prevalence, risk factors and prevention

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    Broiler (meat) chickens have been subjected to intense genetic selection. In the past 50 years, broiler growth rates have increased by over 300% (from 25 g per day to 100 g per day). There is growing societal concern that many broiler chickens have impaired locomotion or are even unable to walk. Here we present the results of a comprehensive survey of commercial flocks which quantifies the risk factors for poor locomotion in broiler chickens.We assessed the walking ability of 51,000 birds, representing 4.8 million birds within 176 flocks.We also obtained information on approximately 150 different management factors associated with each flock. At a mean age of 40 days, over 27.6% of birds in our study showed poor locomotion and 3.3% were almost unable to walk. The high prevalence of poor locomotion occurred despite culling policies designed to remove severely lame birds from flocks. We show that the primary risk factors associated with impaired locomotion and poor leg health are those specifically associated with rate of growth. Factors significantly associated with high gait score included the age of the bird (older birds), visit (second visit to same flock), bird genotype, not feeding whole wheat, a shorter dark period during the day, higher stocking density at the time of assessment, no use of antibiotic, and the use of intact feed pellets. The welfare implications are profound. Worldwide approximately 261010 broilers are reared within similar husbandry systems.We identify a range of management factors that could be altered to reduce leg health problems, but implementation of these changes would be likely to reduce growth rate and production. A debate on the sustainability of current practice in the production of this important food source is required

    Women’s expectations and experiences of maternity care in NSW - what women highlight as most important

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    Background Although surveys have identified that women are generally highly satisfied with maternity care provision, those aspects of care that women highlight as most important for achieving satisfaction and a satisfactory maternity care experience have not been reported. The aim of this study was to investigate how women understand and experience their maternity care and to report which aspects of care women highlight as most important. Methods This large qualitative study explored women’s expectations and experiences of maternity care provision. In-depth semi-structured interviews were conducted with 53 women experiencing maternity care in a range of tertiary, regional, rural, remote hospitals and midwife-led practices in the state of New South Wales, Australia during 2011 to 2012. Included in the interview schedule was the question ‘What 3 aspects would you see as most important for delivery of maternity care?’ Descriptive analyses of entire transcripts and responses to the question on most important aspects of care were undertaken. Results Descriptive analyses of women’s responses identified 5 important aspects of care: woman-focused care, staff qualities, systems and facilities, family-focused care and continuity of care/information. First-time mothers were more likely to identify woman-focused care, staff qualities and continuity of care/information as important 3 aspects than multiparous mothers. Urban and regional mothers highlighted staff qualities as having greater importance for satisfaction with their care while rural and particularly remote women nominated systems and facilities as important. Conclusions Our study showed that women from a range of settings are more concerned with staff and relational issues than facilities. Differences in perceptions among primiparous versus multiparous women, at different stages of pregnancy and among women from rural and remote compared to urban settings highlight the need to include women with a diversity of experience when trying to understand the aspects of maternity care most important to women

    Cross-species genomic and functional analyses identify a combination therapy using a CHK1 inhibitor and a ribonucleotide reductase inhibitor to treat triple-negative breast cancer

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    INTRODUCTION: Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer that is diagnosed in approximately 15% of all human breast cancer (BrCa) patients. Currently, no targeted therapies exist for this subtype of BrCa and prognosis remains poor. Our laboratory has previously identified a proliferation/DNA repair/cell cycle gene signature (Tag signature) that is characteristic of human TNBC. We hypothesize that targeting the dysregulated biological networks in the Tag gene signature will lead to the identification of improved combination therapies for TNBC. METHODS: Cross-species genomic analysis was used to identify human breast cancer cell lines that express the Tag signature. Knock-down of the up-regulated genes in the Tag signature by siRNA identified several genes that are critical for TNBC cell growth. Small molecule inhibitors to two of these genes were analyzed, alone and in combination, for their effects on cell proliferation, cell cycle, and apoptosis in vitro and tumor growth in vivo. Synergy between the two drugs was analyzed by the Chou-Talalay method. RESULTS: A custom siRNA screen was used to identify targets within the Tag signature that are critical for growth of TNBC cells. Ribonucleotide reductase 1 and 2 (RRM1 and 2) and checkpoint kinase 1 (CHK1) were found to be critical targets for TNBC cell survival. Combination therapy, to simultaneously attenuate cell cycle checkpoint control through inhibition of CHK1 while inducing DNA damage with gemcitabine, improved therapeutic efficacy in vitro and in xenograft models of TNBC. CONCLUSIONS: This combination therapy may have translational value for patients with TNBC and improve therapeutic response for this aggressive form of breast cancer

    Factors Affecting Repeat Visitation and Flow-on Tourism as Sources of Event Strategy Sustainability

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    The sustainability of including medium sized one-time sport events in an event portfolio is examined with reference to the capacity of one such event to stimulate flow-on tourism (i.e. tourism activities beyond the event but around the time of the event), a desire to return to the destination, and positive word-of-mouth. Relationships among four motives (socialising, escape, learning about the destination, and learning about athletics), identification with the event (self and social identity), previous visitation to the host destination, information search, tourism activities, and likelihood of recommending and/or returning to the host destination were examined for four categories of attendees at the Pan American Junior Athletics Championships: primary purpose spectators, casual spectators, athletes, and non-athlete participants. All four categories of attendee engaged in some information search and participated in flow-on tourism, but to a low degree. Information search fostered flow-on tourism. Classic tourism activities (e.g. sightseeing, visiting museums) were motivated by a desire to learn about the destination, and encouraged future visitation and likelihood of recommendation. It is concluded that medium-sized one-time sport events can play a sustainable role in event portfolios, but their efficacy requires greater integration of destination experiences with the event. It is suggested that future work should examine the means to cultivate that integration, including creation of more effective alliances between destination marketers and event organizers

    Evaluation of community-level interventions to increase early initiation of antenatal care in pregnancy: protocol for the Community REACH study, a cluster randomised controlled trial with integrated process and economic evaluations

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    BACKGROUND: The provision of high-quality maternity services is a priority for reducing inequalities in health outcomes for mothers and infants. Best practice includes women having their initial antenatal appointment within the first trimester of pregnancy in order to provide screening and support for healthy lifestyles, well-being and self-care in pregnancy. Previous research has identified inequalities in access to antenatal care, yet there is little evidence on interventions to improve early initiation of antenatal care. The Community REACH trial will assess the effectiveness and cost-effectiveness of engaging communities in the co-production and delivery of an intervention that addresses this issue. METHODS/DESIGN: The study design is a matched cluster randomised controlled trial with integrated process and economic evaluations. The unit of randomisation is electoral ward. The intervention will be delivered in 10 wards; 10 comparator wards will have normal practice. The primary outcome is the proportion of pregnant women attending their antenatal booking appointment by the 12th completed week of pregnancy. This and a number of secondary outcomes will be assessed for cohorts of women (n = approximately 1450 per arm) who give birth 2-7 and 8-13 months after intervention delivery completion in the included wards, using routinely collected maternity data. Eight hospitals commissioned to provide maternity services in six NHS trusts in north and east London and Essex have been recruited to the study. These trusts will provide anonymised routine data for randomisation and outcomes analysis. The process evaluation will examine intervention implementation, acceptability, reach and possible causal pathways. The economic evaluation will use a cost-consequences analysis and decision model to evaluate the intervention. Targeted community engagement in the research process was a priority. DISCUSSION: Community REACH aims to increase early initiation of antenatal care using an intervention that is co-produced and delivered by local communities. This pragmatic cluster randomised controlled trial, with integrated process and economic evaluation, aims to rigorously assess the effectiveness of this public health intervention, which is particularly complex due to the required combination of standardisation with local flexibility. It will also answer questions about scalability and generalisability. TRIAL REGISTRATION: ISRCTN registry: registration number 63066975 . Registered on 18 August 2015

    Creative and Stylistic Devices Employed by Children During a Storybook Narrative Task: A Cross-Cultural Study

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    Purpose: The purpose of this study was to analyze the effects of culture on the creative and stylistic features children employ when producing narratives based on wordless picture books. Method: Participants included 60 first- and second-grade African American, Latino American, and Caucasian children. A subset of narratives based on wordless picture books collected as part of a larger study was coded and analyzed for the following creative and stylistic conventions: organizational style (topic centered, linear, cyclical), dialogue (direct, indirect), reference to character relationships (nature, naming, conduct), embellishment (fantasy, suspense, conflict), and paralinguistic devices (expressive sounds, exclamatory utterances). Results: Many similarities and differences between ethnic groups were found. No significant differences were found between ethnic groups in organizational style or use of paralinguistic devices. African American children included more fantasy in their stories, Latino children named their characters more often, and Caucasian children made more references to the nature of character relationships. Conclusion: Even within the context of a highly structured narrative task based on wordless picture books, culture influences children’s production of narratives. Enhanced understanding of narrative structure, creativity, and style is necessary to provide ecologically valid narrative assessment and intervention for children from diverse cultural backgrounds
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