569 research outputs found

    Testing metallicity indicators at z~1.4 with the gravitationally lensed galaxy CASSOWARY 20

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    We present X-shooter observations of CASSOWARY 20 (CSWA 20), a star-forming (SFR ~6 Msol/yr) galaxy at z=1.433, magnified by a factor of 11.5 by the gravitational lensing produced by a massive foreground galaxy at z=0.741. We analysed the integrated physical properties of the HII regions of CSWA 20 using temperature- and density-sensitive emission lines. We find the abundance of oxygen to be ~1/7 of solar, while carbon is ~50 times less abundant than in the Sun. The unusually low C/O ratio may be an indication of a particularly rapid timescale of chemical enrichment. The wide wavelength coverage of X-shooter gives us access to five different methods for determining the metallicity of CSWA 20, three based on emission lines from HII regions and two on absorption features formed in the atmospheres of massive stars. All five estimates are in agreement, within the factor of ~2 uncertainty of each method. The interstellar medium of CSWA 20 only partially covers the star-forming region as viewed from our direction; in particular, absorption lines from neutrals and first ions are exceptionally weak. We find evidence for large-scale outflows of the interstellar medium (ISM) with speeds of up 750 km/s, similar to the values measured in other high-z galaxies sustaining much higher rates of star formation.Comment: 18 pages, 11 figures, accepted for publication in MNRA

    Application of the IDEAS Framework in Adapting a Web-Based Physical Activity Intervention for Young Adult College Students

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    User-centered developmental processes are critical to ensuring acceptability of e-health behavioral interventions, and yet physical activity research continues to be inundated with top-down developmental approaches. The IDEAS (Integrate, Design, Assess, and Share) framework outlines a user-centered process for development of e-health interventions. The purpose of this manuscript is to describe the application of the IDEAS framework in adapting a web-based physical activity intervention for young adult college students. Steps 1–3 emphasized integrating insights from users and theory and Steps 4–7 focused on iterative and rapid design with user feedback. Data were collected via repeat qualitative interviews with young adult college students (N = 7). Resulting qualitative metathemes were engagement, accountability, and cultural fit. Therefore, intervention modifications focused on strategies to foster ongoing engagement with the program (e.g., increase interactivity), support personal and social accountability (e.g., private social media group), and provide a cultural fit within the college lifestyle (e.g., images relevant to student life). The resulting web-based intervention included eight weekly lessons, an expanded resource library, “how-to” videos, step and goal trackers, and a private social media group to be led by a wellness coach. In conclusion, the IDEAS framework guided an efficient, user-centered adaptation process that integrated empirical evidence and behavior change theory with user preferences and feedback. Furthermore, the process allowed us to address barriers to acceptability during the design and build stages rather than at later stages of pilot and efficacy testing

    Tourism Business Resilience for Coastal Virginia Assessment Report

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    This report summarizes the results of the Tourism Business Resilience Project conducted by the Commonwealth Center for Recurrent Flooding Resiliency and Virginia Sea Grant. This project was a joint effort by faculty and students from the Old Dominion University Resilience Collaborative and the Virginia Coastal Policy Center at the William & Mary Law School

    Association between Physical Activity and Sport Participation on Hemoglobin A1c among Children and Adolescents with Type 1 Diabetes

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    Purpose: To determine associations between physical activity (PA) and sport participation on HbA1c levels in children with type 1 diabetes (T1D). Method: Pediatric patients with T1D were invited to complete a PA and sport participation survey. Data were linked to their medical records for demographic characteristics, diabetes treatment and monitoring plans, and HbA1c levels. Results: Participants consisted of 71 females and 81 males, were 13 +- 3 years old with an average HbA1c level of 8.75 +- 1.81. Children accumulating 60 min of activity 3 days or more a week had significantly lower HbA1c compared to those who accumulated less than 3 days (p \u3c 0.01) of 60 min of activity. However, there was no significant difference in HbA1c values based on sport participation groups. A multiple linear regression model indicated that PA, race, age, duration of diagnosis, and CGM use all significantly predicted HbA1c (p \u3c 0.05). Conclusion: This study demonstrated the significant relationship between daily PA and HbA1c. Those in this sample presented with lower HbA1c values even if accumulating less than the recommended number of days of activity. Further, it was shown that sport participation alone may not be adequate enough to impact HbA1c in a similar manner

    On the biological and genetic diversity in Neospora caninum

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    Published: 22 March 2010Neospora caninum is a parasite regarded a major cause of foetal loss in cattle. A key requirement to an understanding of the epidemiology and pathogenicity of N. caninum is knowledge of the biological characteristics of the species and the genetic diversity within it. Due to the broad intermediate host range of the species, worldwide geographical distribution and its capacity for sexual reproduction, significant biological and genetic differences might be expected to exist. N. caninum has now been isolated from a variety of different host species including dogs and cattle. Although isolates of this parasite show only minor differences in ultrastructure, considerable differences have been reported in pathogenicity using mainly mouse models. At the DNA level, marked levels of polymorphism between isolates were detected in mini- and microsatellites found in the genome of N. caninum. Knowledge of what drives the biological differences that have been observed between the various isolates at the molecular level is crucial in aiding our understanding of the epidemiology of this parasite and, in turn, the development of efficacious strategies, such as live vaccines, for controlling its impact. The purpose of this review is to document and discuss for the first time, the nature of the diversity found within the species Neospora caninum.Sarwat E. Al-Qassab, Michael P. Reichel and John T. Elli

    Extensive production of Neospora caninum tissue cysts in a carnivorous marsupial succumbing to experimental neosporosis

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    Experimental infections of Sminthopsis crassicaudata, the fat-tailed dunnart, a carnivorous marsupial widely distributed throughout the arid and semi-arid zones of Australia, show that this species can act as an intermediate host for Neospora caninum. In contrast to existing models that develop relatively few N. caninum tissue cysts, dunnarts offer a new animal model in which active neosporosis is dominated by tissue cyst production. The results provide evidence for a sylvatic life cycle of N. caninum in Australia between marsupials and wild dogs. It establishes the foundation for an investigation of the impact and costs of neosporosis to wildlife

    Dark energy constraints from cosmic shear power spectra: impact of intrinsic alignments on photometric redshift requirements

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    Cosmic shear constrains cosmology by exploiting the apparent alignments of pairs of galaxies due to gravitational lensing by intervening mass clumps. However galaxies may become (intrinsically) aligned with each other, and with nearby mass clumps, during their formation. This effect needs to be disentangled from the cosmic shear signal to place constraints on cosmology. We use the linear intrinsic alignment model as a base and compare it to an alternative model and data. If intrinsic alignments are ignored then the dark energy equation of state is biased by ~50 per cent. We examine how the number of tomographic redshift bins affects uncertainties on cosmological parameters and find that when intrinsic alignments are included two or more times as many bins are required to obtain 80 per cent of the available information. We investigate how the degradation in the dark energy figure of merit depends on the photometric redshift scatter. Previous studies have shown that lensing does not place stringent requirements on the photometric redshift uncertainty, so long as the uncertainty is well known. However, if intrinsic alignments are included the requirements become a factor of three tighter. These results are quite insensitive to the fraction of catastrophic outliers, assuming that this fraction is well known. We show the effect of uncertainties in photometric redshift bias and scatter. Finally we quantify how priors on the intrinsic alignment model would improve dark energy constraints.Comment: 14 pages and 9 figures. Replaced with final version accepted in "Gravitational Lensing" Focus Issue of the New Journal of Physics at http://www.iop.org/EJ/abstract/1367-2630/9/12/E0

    Efficacy of novel recombinant fowlpox vaccine against recent Mexican H7N3 highly pathogenic avian influenza virus

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    Since 2012, H7N3 highly pathogenic avian influenza (HPAI) has produced negative economic and animal welfare impacts on poultry in central Mexico. In the present study, chickens were vaccinated with two different recombinant fowlpox virus vaccines (rFPV-H7/3002 with 2015 H7 hemagglutinin [HA] gene insert, and rFPV-H7/2155 with 2002 H7 HA gene insert), and were then challenged three weeks later with H7N3 HPAI virus (A/chicken/Jalisco/CPA-37905/2015). The rFPV-H7/3002 vaccine conferred 100% protection against mortality and morbidity, and significantly reduced virus shed titers from the respiratory and gastrointestinal tracts. In contrast, 100% of sham and rFPV-H7/2155 vaccinated birds shed virus at higher titers and died within 4 days. Pre- (15/20) and post- (20/20) challenge serum of birds vaccinated with rFPV-H7/3002 had antibodies detectable by hemagglutination inhibition (HI) assay using challenge virus antigen. However, only a few birds (3/20) in the rFPV-H7/2155 vaccinated group had antibodies that reacted against the challenge strain but all birds had antibodies that reacted against the homologous vaccine antigen (A/turkey/Virginia/SEP-66/2002) (20/20). One possible explanation for differences in vaccines efficacy is the antigenic drift between circulating viruses and vaccines. Molecular analysis demonstrated that the Mexican H7N3 strains have continued to rapidly evolve since 2012. In addition, we identified in silico three potential new N-glycosylation sites on the globular head of the H7 HA of A/chicken/Jalisco/CPA-37905/2015 challenge virus, which were absent in 2012 H7N3 outbreak virus. Our results suggested that mutations in the HA antigenic sites including increased glycosylation sites, accumulated in the new circulating Mexican H7 HPAIV strains, altered the recognition of neutralizing antibodies from the older vaccine strain rFPV-H7/2155. Therefore, the protective efficacy of novel rFPV-H7/3002 against recent outbreak Mexican H7N3 HPAIV confirms the importance of frequent updating of vaccines seed strains for long-term effective control of H7 HPAI virus.info:eu-repo/semantics/publishedVersio

    Impact of Vitamin C on Endothelial Function and Exercise Capacity in Patients with a Fontan Circulation

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    Objective.  To evaluate the impact of antioxidant therapy on functional health status in Fontan‐palliated patients. Design.  Prospective, randomized, double‐blind, placebo‐controlled trial. Patients.  Fifty‐three generally asymptomatic Fontan patients. Interventions.  Patients were randomized to receive either high‐dose ascorbic acid (vitamin C) or placebo for 4 weeks. Outcome Measures.  Peripheral vascular function, as measured with endothelium‐dependent digital pulse amplitude testing (EndoPAT), and exercise capacity were assessed before and after study drug treatment. Primary outcome measures included the EndoPAT index and peripheral arterial tonometry (PAT) ratio, both validated markers of vascular function. Secondary outcome measures included peak oxygen consumption and work. Results.  Twenty‐three vitamin C‐ and 21 placebo‐assigned subjects completed the protocol (83%). Median age and time from Fontan completion were 15 (interquartile range [IQR] 11.7–18.2) and 11.9 years (IQR 9.0–15.7), respectively. Right ventricular morphology was dominant in 30 (57%). Outcome measures were similar between groups at baseline. Among all subjects, vitamin C therapy was not associated with a statistical improvement in either primary or secondary outcome measures. In subjects with abnormal vascular function at baseline, compared with placebo, vitamin C therapy more frequently resulted in normalization of the EndoPAT index (45% vs. 17%) and PAT ratio (38% vs. 13%). Conclusions.  Short‐term therapy with vitamin C does not alter endothelial function or exercise capacity in an asymptomatic Fontan population overall. Vitamin C may provide benefit to a subset of Fontan patients with abnormal vascular function.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92126/1/j.1747-0803.2011.00605.x.pd

    A density-temperature description of the outer electron radiation belt during geomagnetic storms

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    Bi-Maxwellian fits are made to energetic-electron flux measurements from seven satellites in geosynchronous orbit, yielding a number density (n) and temperature (T) description of the outer electron radiation belt. For 54.5 spacecraft years of measurements the median value of n is 3.7 × 10−4 cm−3, and the median value of T is 148 keV. General statistical properties of n, T, and the 1.1–1.5 MeV flux F are investigated, including local-time and solar-cycle dependencies. Using superposed-epoch analysis where the zero epoch is convection onset, the evolution of the outer electron radiation belt through high-speed-stream-driven storms is investigated. The number-density decay during the calm before the storm, relativistic-electron dropouts and recoveries, and the heating of the outer electron radiation belt during storms are analyzed. Using four different “triggers” (sudden storm commencement (SSC), southward interplanetary magnetic field (IMF) portions of coronal mass ejection (CME) sheaths, southward-IMF portions of magnetic clouds, and minimum Dst) a selection of CME-driven storms are analyzed with superposed-epoch techniques. For CME-driven storms, only a very modest density decay prior to storm onset is found. In addition, the compression of the outer electron radiation belt at the time of SSC is analyzed, the number-density increase and temperature decrease during storm main phase are characterized, and the increase in density and temperature during storm recovery phase is determined. During the different phases of storms, changes in the flux are sometimes in response to changes in the temperature, sometimes to changes in the number density, and sometimes to changes in both. Differences are found between the density-temperature and flux descriptions, and it is concluded that more information is available using the density-temperature description
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