2,882 research outputs found
The SMC SNR 1E0102.2-7219 as a Calibration Standard for X-ray Astronomy in the 0.3-2.5 keV Bandpass
The flight calibration of the spectral response of CCD instruments below 1.5
keV is difficult in general because of the lack of strong lines in the on-board
calibration sources typically available. We have been using 1E 0102.2-7219, the
brightest supernova remnant in the Small Magellanic Cloud, to evaluate the
response models of the ACIS CCDs on the Chandra X-ray Observatory (CXO), the
EPIC CCDs on the XMM-Newton Observatory, the XIS CCDs on the Suzaku
Observatory, and the XRT CCD on the Swift Observatory. E0102 has strong lines
of O, Ne, and Mg below 1.5 keV and little or no Fe emission to complicate the
spectrum. The spectrum of E0102 has been well characterized using
high-resolution grating instruments, namely the XMM-Newton RGS and the CXO
HETG, through which a consistent spectral model has been developed that can
then be used to fit the lower-resolution CCD spectra. We have also used the
measured intensities of the lines to investigate the consistency of the
effective area models for the various instruments around the bright O (~570 eV
and 654 eV) and Ne (~910 eV and 1022 eV) lines. We find that the measured
fluxes of the O VII triplet, the O VIII Ly-alpha line, the Ne IX triplet, and
the Ne X Ly-alpha line generally agree to within +/-10 % for all instruments,
with 28 of our 32 fitted normalizations within +/-10% of the RGS-determined
value. The maximum discrepancies, computed as the percentage difference between
the lowest and highest normalization for any instrument pair, are 23% for the O
VII triplet, 24% for the O VIII Ly-alpha line, 13% for the Ne IX triplet, and
19% for the Ne X Ly-alpha line. If only the CXO and XMM are compared, the
maximum discrepancies are 22% for the O VII triplet, 16% for the O VIII
Ly-alpha line, 4% for the Ne IX triplet, and 12% for the Ne X Ly-alpha line.Comment: 16 pages, 11 figures, to be published in Proceedings of the SPIE
7011: Space Telescopes and Instrumentation II: Ultraviolet to Gamma Ray 200
Prediction of liver disease in patients whose liver function tests have been checked in primary care : model development and validation using population-based observational cohorts
This work was supported by the UK National Health Service Research & Development Programme Health Technology Assessment Programme (project number 03/38/02) and also by the Backett Weir Russell Career Development Fellowship, University of Aberdeen.OBJECTIVE: To derive and validate a clinical prediction model to estimate the risk of liver disease diagnosis following liver function tests (LFTs) and to convert the model to a simplified scoring tool for use in primary care. DESIGN: Population-based observational cohort study of patients in Tayside Scotland identified as having their LFTs performed in primary care and followed for 2â
years. Biochemistry data were linked to secondary care, prescriptions and mortality data to ascertain baseline characteristics of the derivation cohort. A separate validation cohort was obtained from 19 general practices across the rest of Scotland to externally validate the final model. SETTING: Primary care, Tayside, Scotland. PARTICIPANTS: Derivation cohort: LFT results from 310â
511 patients. After exclusions (including: patients under 16â
years, patients having initial LFTs measured in secondary care, bilirubin >35â
ÎŒmol/L, liver complications within 6â
weeks and history of a liver condition), the derivation cohort contained 95â
977 patients with no clinically apparent liver condition. Validation cohort: after exclusions, this cohort contained 11â
653 patients. PRIMARY AND SECONDARY OUTCOME MEASURES: Diagnosis of a liver condition within 2â
years. RESULTS: From the derivation cohort (n=95â
977), 481 (0.5%) were diagnosed with a liver disease. The model showed good discrimination (C-statistic=0.78). Given the low prevalence of liver disease, the negative predictive values were high. Positive predictive values were low but rose to 20-30% for high-risk patients. CONCLUSIONS: This study successfully developed and validated a clinical prediction model and subsequent scoring tool, the Algorithm for Liver Function Investigations (ALFI), which can predict liver disease risk in patients with no clinically obvious liver disease who had their initial LFTs taken in primary care. ALFI can help general practitioners focus referral on a small subset of patients with higher predicted risk while continuing to address modifiable liver disease risk factors in those at lower risk.Publisher PDFPeer reviewe
Simple matrix models for random Bergman metrics
Recently, the authors have proposed a new approach to the theory of random
metrics, making an explicit link between probability measures on the space of
metrics on a Kahler manifold and random matrix models. We consider simple
examples of such models and compute the one and two-point functions of the
metric. These geometric correlation functions correspond to new interesting
types of matrix model correlators. We study a large class of examples and
provide in particular a detailed study of the Wishart model.Comment: 23 pages, IOP Latex style, diastatic function Eq. (22) and contact
terms in Eqs. (76, 95) corrected, typos fixed. Accepted to JSTA
The effect of impact angle on craters formed by hypervelocity particles
The Space Power Institute (SPI) at Auburn University has conducted experiments on the effects of impact angle on crater morphology and impactor residue retention for hypervelocity impacts. Copper target plates were set at angles of 30 deg, 45 deg, 60 deg, and 75 deg from the particle flight path. For the 30 deg and 45 deg impacts, in the velocity regime greater than 8 km s(exp -1) the resultant craters are almost identical to normal incidence impacts. The only difference found was in the apparent distribution of particle residue within the crater, and further research is needed to verify this. The 60 deg and 75 deg impacts showed marked differences in crater symmetry, crater lip shape, and particle residue distribution in the same velocity regime. Impactor residue shock fractionation effects have been quantified in first-order. It is concluded that a combination of analysis techniques can yield further information on impact velocity, direction, and angle of incidence
V344 Lyrae: A Touchstone SU UMa Cataclysmic Variable in the Kepler Field
We report on the analysis of the Kepler short-cadence (SC) light curve of
V344 Lyr obtained during 2009 June 20 through 2010 Mar 19 (Q2--Q4). The system
is an SU UMa star showing dwarf nova outbursts and superoutbursts, and promises
to be a touchstone for CV studies for the foreseeable future. The system
displays both positive and negative superhumps with periods of 2.20 and
2.06-hr, respectively, and we identify an orbital period of 2.11-hr. The
positive superhumps have a maximum amplitude of ~0.25-mag, the negative
superhumps a maximum amplitude of ~0.8 mag, and the orbital period at
quiescence has an amplitude of ~0.025 mag. The quality of the Kepler data is
such that we can test vigorously the models for accretion disk dynamics that
have been emerging in the past several years. The SC data for V344 Lyr are
consistent with the model that two physical sources yield positive superhumps:
early in the superoutburst, the superhump signal is generated by viscous
dissipation within the periodically flexing disk, but late in the
superoutburst, the signal is generated as the accretion stream bright spot
sweeps around the rim of the non-axisymmetric disk. The disk superhumps are
roughly anti-phased with the stream/late superhumps. The V344 Lyr data also
reveal negative superhumps arising from accretion onto a tilted disk precessing
in the retrograde direction, and suggest that negative superhumps may appear
during the decline of DN outbursts. The period of negative superhumps has a
positive dP/dt in between outbursts.Comment: ApJ, In Press (20 pages, 27 figures) A version with full-resolution
figures is available at http://www.astro.fit.edu/wood/WoodV344.pd
An integrated solution for runtime compliance governance
Abstract. In response to recent financial scandals (e.g. those involving Enron, Fortis, Parmalat), new regulations for protecting the society from financial and operational risks of the companies have been introduced. Therefore, companies are required to assure compliance of their operations with those new regulations as well as those already in place. Regulations are only one example of compliance sources modern organizations deal with every day. Other sources of compliance include licenses of business partners and other contracts, internal policies, and international standards. The diversity of compliance sources introduces the problem of compliance governance in an organization. In this paper, we propose an integrated solution for runtime compliance governance in Service-Oriented Architectures (SOAs). We show how the proposed solution supports the whole cycle of compliance management: from modeling compliance requirements in domain-specific languages through monitoring them during process execution to displaying information about the current state of compliance in dashboards. We focus on the runtime part of the proposed solution and describe it in detail. We apply the developed framework in a real case study coming from EU FP7 project COMPAS, and this case study is used through the paper to illustrate our solution
Biology, Ecology, and Management of Nonnative Ambrosia Beetles (Coleoptera: Curculionidae: Scolytinae) in Ornamental Plant Nurseries
Xylosandrus germanus (Blandford) and Xylosandrus crassiusculus (Motschulsky) (Coleoptera: Curculionidae: Scolytinae) are two of the most damaging nonnative ambrosia beetle pests in ornamental plant nurseries. Adult females tunnel into the stems and branches of host plants to create galleries with brood chambers. Hosts are infected with symbiotic Ambrosiella spp. fungi that serve as food for the larvae and adults. Plants can also become infected with secondary opportunistic pathogens, including Fusarium spp. Both X. germanus and X. crassiusculus have broad host ranges, and infestations can result in âtoothpicksâ of extruded chewed wood and sap flow associated with gallery entrances, canopy dieback, stem and trunk cankers, and plant death. Beetles efficiently locate and preferentially attack living, weakened plants, especially those physiologically stressed by flooding, inadequate drainage, frost injury, or winter injury and low temperature. Maintaining plant health is the foundation of a management plan. Vulnerable hosts can be partially protected with preventive pyrethroid applications in the spring before peak flight and attack, which are monitored using ethanol-based trapping tactics
Testing implementation facilitation of a primary care-based collaborative care clinical program using a hybrid type III interrupted time series design: a study protocol
Abstract
Background
Dissemination of evidence-based practices that can reduce morbidity and mortality is important to combat the growing opioid overdose crisis in the USA. Research and expert consensus support reducing high-dose opioid therapy, avoiding risky opioid-benzodiazepine combination therapy, and promoting multi-modal, collaborative models of pain care. Collaborative care interventions that support primary care providers have been effective in medication tapering. We developed a patient-centered Primary Care-Integrated Pain Support (PIPS) collaborative care clinical program based on effective components of previous collaborative care interventions. Implementation facilitation, a multi-faceted and dynamic strategy involving the provision of interactive problem-solving and support during implementation of a new program, is used to support key organizational staff throughout PIPS implementation. The primary aim of this study is to evaluate the effectiveness of the implementation facilitation strategy for implementing and sustaining PIPS in the Veterans Health Administration (VHA). The secondary aim is to examine the effect of the program on key patient-level clinical outcomesâtransitioning to safer regimens and enhancing access to complementary and integrative health treatments. The tertiary aim is to determine the categorical costs and ultimate budget impact of PIPS implementation.
Methods
This multi-site study employs an interrupted time series, hybrid type III design to evaluate the effectiveness of implementation facilitation for a collaborative care clinical programâPIPSâin primary care clinics in three geographically diverse VHA health care systems (sites). Participants include pharmacists and allied staff involved in the delivery of clinical pain management services as well as patients. Eligible patients are prescribed either an outpatient opioid prescription greater than or equal to 90Â mg morphine equivalent daily dose or a combination opioid-benzodiazepine regimen. They must also have an upcoming appointment in primary care. The Consolidated Framework for Implementation Research will guide the mixed methods work across the formative evaluation phases and informs the selection of activities included in implementation facilitation. The RE-AIM framework will be used to assess Reach, Effectiveness, Adoption, Implementation, and Maintenance of PIPS.
Discussion
This implementation study will provide important insight into the effectiveness of implementation facilitation to enhance uptake of a collaborative care program in primary care, which targets unsafe opioid prescribing practices.https://deepblue.lib.umich.edu/bitstream/2027.42/146542/1/13012_2018_Article_838.pd
Genome Resources for ClimateâResilient Cowpea, an Essential Crop for Food Security
Cowpea (Vigna unguiculata L. Walp.) is a legume crop that is resilient to hot and droughtâprone climates, and a primary source of protein in subâSaharan Africa and other parts of the developing world. However, genome resources for cowpea have lagged behind most other major crops. Here we describe foundational genome resources and their application to the analysis of germplasm currently in use in West African breeding programs. Resources developed from the African cultivar IT97Kâ499â35 include a wholeâgenome shotgun (WGS) assembly, a bacterial artificial chromosome (BAC) physical map, and assembled sequences from 4355 BACs. These resources and WGS sequences of an additional 36 diverse cowpea accessions supported the development of a genotyping assay for 51 128 SNPs, which was then applied to five biâparental RIL populations to produce a consensus genetic map containing 37 372 SNPs. This genetic map enabled the anchoring of 100 Mb of WGS and 420 Mb of BAC sequences, an exploration of genetic diversity along each linkage group, and clarification of macrosynteny between cowpea and common bean. The SNP assay enabled a diversity analysis of materials from West African breeding programs. Two major subpopulations exist within those materials, one of which has significant parentage from South and East Africa and more diversity. There are genomic regions of high differentiation between subpopulations, one of which coincides with a cluster of nodulin genes. The new resources and knowledge help to define goals and accelerate the breeding of improved varieties to address food security issues related to limitedâinput smallâholder farming and climate stress
Hyperbolic Equations for Vacuum Gravity Using Special Orthonormal Frames
By adopting Nester's higher dimensional special orthonormal frames (HSOF) the
tetrad equations for vacuum gravity are put into first order symmetric
hyperbolic (FOSH) form with constant coefficients, independent of any time
slicing or coordinate specialization.Comment: 14 pages, 3 figures, LaTeX, 13 macros. CQG 14 (1997) 1237-1247 has
algebraic errors. +/- signs in Equations (2), (4) and (5) are here corrected,
and factors of 2 added to Eqs. (18) and (19
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