1,283 research outputs found

    Oscillating bounce solutions and vacuum tunneling in de Sitter spacetime

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    We study a class of oscillating bounce solutions to the Euclidean field equations for gravity coupled to a scalar field theory with two, possibly degenerate, vacua. In these solutions the scalar field crosses the top of the potential barrier k>1k>1 times. Using analytic and numerical methods, we examine how the maximum allowed value of kk depends on the parameters of the theory. For a wide class of potentials kmaxk_{\rm max} is determined by the value of the second derivative of the scalar field potential at the top of the barrier. However, in other cases, such as potentials with relatively flat barriers, the determining parameter appears instead to be the value of this second derivative averaged over the width of the barrier. As a byproduct, we gain additional insight into the conditions under which a Coleman-De Luccia bounce exists. We discuss the physical interpretation of these solutions and their implications for vacuum tunneling transitions in de Sitter spacetime.Comment: 31 pages, 11 figure

    Demolition-only urban policy leads to economic and social isolation.

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    The past two years have seen more than 10,000 homes demolished in Detroit, Michigan. Such demolition policies which have no follow-up plans for development have gone from being controversial to the norm. In new research, Jason Hackworth questions the logic and practice of these policies, finding that the neighborhoods which have had the most demolitions are more economically and socially isolated than they were in 1970. He argues that vacant lots can be a negative force on nearby house values, and that cleared sites never attract the kind of investment money that a derelict house might

    Changes in output, employment and wages during recessions in the United Kingdom

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    Employment has fallen during this recession but by much less than the fall in output. This article examines how the behaviour of the labour market compares with previous recessions. A number of factors, including greater flexibility in real wages, may have helped to mitigate the fall in employment to date. But there is considerable uncertainty about how the labour market will evolve.

    The Trauma Registry Compared to All Patient Refined Diagnosis Related Groups (APR DRG)

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    Background Literature has shown there are significant differences between administrative databases and clinical registry data. Our objective was to compare the identification of trauma patients using All Patient Refined Diagnosis Related Groups (APR-DRG) as compared to the Trauma Registry and estimate the effects of those discrepancies on utilization. Methods Admitted pediatric patients from 1/2012–12/2013 were abstracted from the trauma registry. The patients were linked to corresponding administrative data using the Pediatric Health Information System database at a single children’s hospital. APR-DRGs referencing trauma were used to identify trauma patients. We compared variables related to utilization and diagnosis to determine the level of agreement between the two datasets. Results There were 1942 trauma registry patients and 980 administrative records identified with trauma-specific APR-DRG during the study period. Forty-two percent (816/1942) of registry records had an associated trauma-specific APR-DRG; 69% of registry patients requiring ICU care had trauma APR-DRGs; 73% of registry patients with head injuries had trauma APR-DRGs. Only 21% of registry patients requiring surgical management had associated trauma APR-DRGs, and 12.5% of simple fractures had associated trauma APR-DRGs. Conclusion APR-DRGs appeared to only capture a fraction of the entire trauma population and it tends to be the more severely ill patients. As a result, the administrative data was not able to accurately answer hospital or operating room utilization as well as specific information on diagnosis categories regarding trauma patients. APR-DRG administrative data should not be used as the only data source for evaluating the needs of a trauma program

    Coleman - de Luccia instanton of the second order in a brane world

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    The second order Coleman - de Luccia instanton and its action in the Randall - Sundrum type II model are investigated and the comparison with the results in Einstein's general relativity is done in the present paper.Comment: 4 pages, accepted in IJT

    The Skyrme Energy Functional and Naturalness

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    Recent studies show that successful relativistic mean-field models of nuclei are consistent with naive dimensional analysis and naturalness, as expected in low-energy effective field theories of quantum chromodynamics. The nonrelativistic Skyrme energy functional is found to have similar characteristics.Comment: 8 pages, REVTeX 3.0 with epsf.sty, plus 2 figure

    Physical Examination is the Best Predictor of the Need for Abdominal Surgery in Children Following Motor Vehicle Collision

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    BACKGROUND: Exploratory laparotomy in children after motor vehicle collision (MVC) is rare. In the absence of definitive hemorrhage or free abdominal air on radiographic imaging, predictors for operative exploration are conflicting. OBJECTIVE: The purpose of this study was to explore objective findings that may aid in determining which children require operative abdominal exploration after MVC. METHODS: Data from 2010-2014 at an American College of Surgeons-certified level 1 pediatric trauma center were retrospectively reviewed. Demographics, vital signs, laboratory data, radiologic studies, operative records, associated injuries, and outcomes were analyzed and p < 0.05 was considered statistically significant. RESULTS: Eight hundred sixty-two patients 0-18 years of age presented to the hospital after an MVC during the study period. Seventeen patients (2.0%) required abdominal exploration and all were found to have intraabdominal injuries. Respiratory rate was the only vital sign that was significantly altered (p = 0.04) in those who required abdominal surgery compared with those who did not. Physical examination findings, such as the seat belt sign, abdominal bruising, abdominal wound, and abdominal tenderness, were present significantly more frequently in those requiring abdominal surgery (p < 0.0001). Each finding had a negative predictive value for the need for operative exploration of at least 0.98. There were no significant differences in trauma laboratory values or radiographic findings between the 2 groups. CONCLUSION: Data from this study solidify the relationship between specific physical examination findings and the need for abdominal exploration after MVC in children. In addition, these data suggest that a lack of the seat belt sign, abdominal bruising, abdominal wounds, or abdominal tenderness are individually predictive of patients who will not require surgical intervention

    Impact of a brief group intervention to enhance parenting and the home learning environment for children aged 6-36 months: A cluster randomised controlled trial

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    This is the final version of the article. Available from the publisher via the DOI in this record.This study evaluated the effectiveness of a group parenting intervention designed to strengthen the home learning environment of children from disadvantaged families. Two cluster randomised controlled superiority trials were conducted in parallel and delivered within existing services: a 6-week parenting group (51 locations randomised; 986 parents) for parents of infants (aged 6-12 months), and a 10-week facilitated playgroup (58 locations randomised; 1200 parents) for parents of toddlers (aged 12-36 months). Each trial had three conditions: intervention (smalltalk group-only); enhanced intervention with home coaching (smalltalk plus); and 'standard'/usual practice controls. Parent-report and observational measures were collected at baseline, 12 and 32 weeks follow-up. Primary outcomes were parent verbal responsivity and home learning activities at 32 weeks. In the infant trial, there were no differences by trial arm for the primary outcomes at 32 weeks. In the toddler trial at 32-weeks, participants in the smalltalk group-only trial showed improvement compared to the standard program for parent verbal responsivity (effect size (ES) = 0.16; 95% CI 0.01, 0.36) and home learning activities (ES = 0.17; 95% CI 0.01, 0.38) but smalltalk plus did not. For the secondary outcomes in the infant trial, several initial differences favouring smalltalk plus were evident at 12 weeks, but not maintained to 32 weeks. For the toddler trial, differences in secondary outcomes favouring smalltalk plus were evident at 12 weeks and maintained to 32 weeks. These trials provide some evidence of the benefits of a parenting intervention focused on the home learning environment for parents of toddlers but not infants. TRIAL REGISTRATION: 8 September 2011; ACTRN12611000965909 .This research was commissioned and funded by the Victorian Government Department of Education and Early Childhood Development (DEECD), and designed and conducted at the Parenting Research Centre. NH, EW, SB, AS, MT, MY and JN were employees of the Parenting Research Centre when this study was conducted. EW was part-funded by the Centre for Research Excellence in Child Language at Murdoch Childrens Research Institute (NHMRC grant 1023493). NH, EW, SB and JN are funded by the Australian Communities Foundation (Coronella sub-fund) at La Trobe University. OU is supported by the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care South West Peninsula at the Royal Devon and Exeter NHS Foundation Trust. Views expressed are those of the authors and not necessarily those of DEECD, NIHR, NHS or the Department of Health

    Freya at 100.

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    Describes a student organization that has evolved over many years, from one that put on May Day pageants to one that embodies the ideals of Hollins and works anonymously to help the Hollins community.https://digitalcommons.hollins.edu/archival_articles/1006/thumbnail.jp
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