2,065 research outputs found

    The Santa Fe Light Cone Simulation Project: I. Confusion and the WHIM in Upcoming Sunyaev-Zel'dovich Effect Surveys

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    We present the first results from a new generation of simulated large sky coverage (~100 square degrees) Sunyaev-Zeldovich effect (SZE) cluster surveys using the cosmological adaptive mesh refinement N-body/hydro code Enzo. We have simulated a very large (512^3h^{-3}Mpc^3) volume with unprecedented dynamic range. We have generated simulated light cones to match the resolution and sensitivity of current and future SZE instruments. Unlike many previous studies of this type, our simulation includes unbound gas, where an appreciable fraction of the baryons in the universe reside. We have found that cluster line-of-sight overlap may be a significant issue in upcoming single-dish SZE surveys. Smaller beam surveys (~1 arcmin) have more than one massive cluster within a beam diameter 5-10% of the time, and a larger beam experiment like Planck has multiple clusters per beam 60% of the time. We explore the contribution of unresolved halos and unbound gas to the SZE signature at the maximum decrement. We find that there is a contribution from gas outside clusters of ~16% per object on average for upcoming surveys. This adds both bias and scatter to the deduced value of the integrated SZE, adding difficulty in accurately calibrating a cluster Y-M relationship. Finally, we find that in images where objects with M > 5x10^{13} M_{\odot} have had their SZE signatures removed, roughly a third of the total SZE flux still remains. This gas exists at least partially in the Warm Hot Intergalactic Medium (WHIM), and will possibly be detectable with the upcoming generation of SZE surveys.Comment: 14 pages, 13 figures, version accepted to ApJ. Major revisions mad

    Methodology of a reevaluation of cardiovascular outcomes in the RECORD trial: study design and conduct

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    Background In 2010, after regulatory review of rosiglitazone licensing, the US Food and Drug Administration (FDA) requested a reevaluation of cardiovascular end points in the RECORD trial.<p></p> Methods Automated screening of the original clinical trial database and manual case report form review were performed to identify all potential cardiovascular and noncardiovascular deaths, and nonfatal myocardial infarction (MI) and stroke events. Search techniques were used to find participants lost to follow-up, and sites were queried for additional source documents. Suspected events underwent blinded adjudication using both original RECORD end point definitions and new FDA end point definitions, before analysis by the Duke Clinical Research Institute.<p></p> Results The reevaluation effort included an additional 328 person-years of follow-up. Automated screening identified 396 suspected deaths, 2,052 suspected MIs, and 468 suspected strokes. Manual review of documents by Duke Clinical Research Institute clinical events classification (CEC) coordinators identified an additional 31 suspected deaths, 49 suspected MIs, and 28 suspected strokes. There were 127 CEC queries issued requesting additional information on suspected deaths; 43 were closed with no site response, 61 were closed with a response that no additional data were available, and additional data were received for 23. Seventy CEC queries were issued requesting additional information for suspected MI and stroke events; 31 were closed with no site response, 20 were closed with a response that no additional data were available, and 19 resulted in additional data.<p></p> Conclusions Comprehensive procedures were used for rigorous event reascertainment and readjudication in a previously completed open-label, global clinical trial. These procedures used in this unique situation were consistent with other common approaches in the field, were enhanced to address the FDA concerns about the original RECORD trial results, and could be considered by clinical trialists designing event readjudication protocols for drug development programs that have been completed.<p></p&gt

    Concepts for a NASA Applied Spaceflight Environments Office

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    The National Aeronautics and Space Administration (NASA) is launching a bold and ambitious new space initiative. A significant part of this new initiative includes exploration of new worlds, the development of more innovative technologies, and expansion our presence in the solar system. A common theme to this initiative is the exploration of space beyond Low Earth Orbit (LEO). As currently organized, NASA does not have an Agency-level office that provides coordination of space environment research and development. This has contributed to the formation of a gap between spaceflight environments knowledge and the application of this knowledge for multi-program use. This paper outlines a concept to establish a NASA-level Applied Spaceflight Environments (ASE) office that will provide coordination and funding for sustained multi-program support in three technical areas that have demonstrated these needs through customer requests. These technical areas are natural environments characterization and modeling, materials and systems analysis and test, and operational space environments modeling and prediction. This paper will establish the need for the ASE, discuss a concept for organizational structure and outline the scope in the three technical area

    Results of a reevaluation of cardiovascular outcomes in the RECORD trial

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    Background The US Food and Drug Administration (FDA) required a reevaluation of cardiovascular (CV) outcomes in the RECORD trial. This provided an opportunity to assess the implications of event adjudication by 2 groups and quantify the differences as well as to use new FDA end point definitions in development.<p></p> Methods Original data were used to systematically identify all potential deaths, myocardial infarctions (MIs), and strokes. Site investigators were approached for additional source documents and information about participants lost to follow-up. Suspected events were adjudicated using standard procedures, and the results were compared with the original trial outcomes.<p></p> Results Follow-up for mortality was 25,833 person-years, including an additional 328 person-years identified during the reevaluation effort. A total of 184 CV or unknown-cause deaths (88 rosiglitazone, 96 metformin/sulfonylurea), 128 participants with an MI (68 rosiglitazone, 60 metformin/sulfonylurea), and 113 participants with a stroke (50 rosiglitazone, 63 metformin/sulfonylurea) were included. The hazard ratio (HR) for rosiglitazone versus metformin/sulfonylurea for the end point of CV (or unknown cause) death, MI, or stroke was 0.95 (95% CI 0.78-1.17) compared with 0.93 (95% CI 0.74-1.15) for the original RECORD results. Treatment comparisons for MI (HR 1.13, 95% CI 0.80-1.59) and mortality (HR 0.86, 95% CI 0.68-1.08) were also the same compared with the original RECORD results. Sensitivity analyses were also consistent with the original RECORD results. Analyses using the FDA definitions showed similar results.<p></p> Conclusions Only a modest number of additional person-years of follow-up were ascertained from this reevaluation of CV end points in RECORD. Observed HRs and CIs from these analyses using the original RECORD or new FDA end point definitions showed similar treatment effects of rosiglitazone compared with the original RECORD results.<p></p&gt

    Gendered nationalism : the gender gap in support for the Scottish National Party

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    Recent major surveys of the Scottish electorate and of Scottish National Party (SNP) members have revealed a distinct gender gap in support for the party. Men are markedly more likely than women to vote for the SNP and they comprise more than two-thirds of its membership. In this article, we use data from those surveys to test various possible explanations for the disproportionately male support for the SNP. While popular accounts have focused on the gendered appeal of recent leaders and on the party’s fluctuating efforts at achieving gender equality in its parliamentary representation, we find much stronger support for a different explanation. Women are less inclined to support and to join the SNP because they are markedly less supportive of its central objective of independence for Scotland. Since men and women barely differ in their reported national identities, the origins of this gender gap in support for independence presents a puzzle for further research

    Synergistic interactions between XPC and p53 mutations in double-mutant mice: neural tube abnormalities and accelerated UV radiation-induced skin cancer

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    AbstractThe significance of DNA repair to human health has been well documented by studies on xeroderma pigmentosum (XP) patients, who suffer a dramatically increased risk of cancer in sun-exposed areas of their skin [1,2]. This autosomal recessive disorder has been directly associated with a defect in nucleotide excision–repair (NER) [1,2]. Like human XP individuals, mice carrying homozygous mutations in XP genes manifest a predisposition to skin carcinogenesis following exposure to ultraviolet (UV) radiation [3–5]. Recent studies have suggested that, in addition to roles in apoptosis [6] and cell-cycle checkpoint control [7] in response to DNA damage, p53 protein may modulate NER [8]. Mutations in the p53 gene have been observed in 50% of all human tumors [9] and have been implicated in both the early [10] and late [11] stages of skin cancer. To examine the consequences of a combined deficiency of the XPC and the p53 proteins in mice, we generated double-mutant animals. We document a spectrum of neural tube defects in XPC p53 mutant embryos. Additionally, we show that, following exposure to UV-B radiation, XPC p53 mutant mice have more severe solar keratosis and suffer accelerated skin cancer compared with XPC mutant mice that are wild-type with respect to p53
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