1,714 research outputs found

    The WC10 central stars CPD−56° 8032 and He 2–113 –III. Wind electron temperatures and abundances

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    We present a direct spectroscopic measurement of the wind electron temperatures and a determination of the stellar wind abundances of the WC10 central stars of planetary nebulae CPD−56° 8032 and He 2–113, for which high-resolution (0.15-Å) UCLES echelle spectra have been obtained using the 3.9-m Anglo-Australian Telescope. The intensities of dielectronic recombination lines, originating from autoionizing resonance states situated in the C2++e− continuum, are sensitive to the electron temperature through the populations of these states, which are close to their LTE values. The high-resolution spectra allow the intensities of fine-structure components of the dielectronic multiplets to be measured. New atomic data for the autoionization and radiative transition probabilities of the resonance states are presented, and used to derive wind electron temperatures in the two stars of 21 300 K for CPD−56°8032 and 16 400 K for He 2–113. One of the dielectronic lines is shown to have an autoionization width in agreement with the theoretical predictions. Wind abundances of carbon with respect to helium are determined from bound–bound recombination lines, and are found to be C/He=0.44 for CPD−56° 8032 and C/He=0.29 for He 2–113 (by number). The oxygen abundances are determined to be O/He=0.24 for CPD−56° 8032 and 0.26 for He 2–113. The effect of optical depth on the temperature and abundance determinations is investigated by means of a Sobolev escape-probability model. We conclude that the optically thicker recombination lines can still be used for abundance determinations, provided that their upper levels are far from LTE

    Evaluation of routinely reported surgical site infections against microbiological culture results: a tool to identify patient groups where diagnosis and treatment may be improved

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    <p>Abstract</p> <p>Background</p> <p>Surgeons may improve their decision making by assessing the extent to which their initial clinical diagnosis of a surgical site infection (SSI) was supported by culture results. Aim of the present study was to evaluate routinely reported SSI by surgeons against microbiological culture results, to identify patient groups with lower agreement where decision making may be improved.</p> <p>Methods</p> <p>701 admissions with SSI were reported by surgeons in a university medical centre in the period 1997-2005, which were retrospectively checked for microbiological culture results. Reporting a SSI was conditional on treatment being given (e.g. antibiotics) and was classified by severity. To identify specific patient groups, patients were classified according to the surgery group of the first operation during admission (e.g. trauma).</p> <p>Results</p> <p>Of all reported SSI, 523 (74.6%) had a positive culture result, 102 (14.6%) a negative culture result and 76 (10.8%) were classified as unknown culture result (due to no culture taken). Given a known culture result, reported SSI with positive culture results less often concerned trauma patients (16% versus 26%, X<sup>2 </sup>= 4.99 p = 0.03) and less severe SSI (49% versus 85%, X<sup>2 </sup>= 10.11 p < 0.01) suggesting that a more conservative approach may be warranted in these patients. The trauma surgeons themselves perceived to have become too liberal in administering antibiotics (and reporting SSI).</p> <p>Conclusion</p> <p>Routine reporting of SSI was mostly supported by culture results. However, this support was less often found in trauma patients and less severe SSI, thereby giving surgeons feedback that diagnosis and treatment may be improved in these cases.</p

    Exploitation of symmetry in periodic Self-Consistent-Field ab initio calculations: application to large three-dimensional compounds

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    Symmetry can dramatically reduce the computational cost (running time and memory allocation) of Self-Consistent-Field ab initio calculations for crystalline systems. Crucial for running time is use of symmetry in the evaluation of one- and two-electron integrals, diagonalization of the Fock matrix at selected points in reciprocal space, reconstruction of the density matrix. As regards memory allocation, full square matrices (overlap, Fock and density) in the Atomic Orbital (AO) basis are avoided and a direct transformation from the packed AO to the SACO (Symmetry Adapted Crystalline Orbital) basis is performed, so that the largest matrix to be handled has the size of the largest sub-block in the latter basis. We here illustrate the effectiveness of this scheme, following recent advancements in the CRYSTAL code, concerning memory allocation and direct basis set transformation. Quantitative examples are given for large unit cell systems, such as zeolites (all-silica faujasite and silicalite MFI) and garnets (pyrope). It is shown that the full SCF of 3D systems containing up to 576 atoms and 11136 Atomic Orbitals in the cell can be run with a hybrid functional on a single core PC with 500 MB RAM in about 8 h. © 2014 Science China Press and Springer-Verlag Berlin Heidelberg

    Accelerated decline in lung function in smoking women with airway obstruction: SAPALDIA 2 cohort study

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    BACKGROUND: The aim was to determine if effects from smoking on lung function measured over 11 years differ between men and women. METHODS: In a prospective population based cohort study (Swiss Study on Air Pollution and Lung Diseases in Adults) current smokers in 1991 (18 – 60 yrs) were reassessed in 2002 (n = 1792). Multiple linear regression was used to estimate effects from pack-years of cigarettes smoked to 1991 and mean packs of cigarettes smoked per day between 1991 and 2002 on change in lung volume and flows over the 11 years. RESULTS: In both sexes, packs smoked between assessments were related to lung function decline but pack-years smoked before 1991 were not. Mean annual decline in FEV(1 )was -10.4 mL(95%CI -15.3, -5.5) per pack per day between assessments in men and -13.8 mL(95%CI-19.5,-8.1) in women. Decline per pack per day between 1991 and 2002 was lower in women who smoked in 1991 but quit before 2002 compared to persistent smokers (-6.4 vs -11.6 mL, p = 0.05) but this was not seen in men (-14.3 vs -8.8 mL p = 0.49). Smoking related decline was accelerated in men and women with airway obstruction, particularly in women where decline in FEV(1 )was three fold higher in participants with FEV1/FVC<0.70 compared to other women (-39.4 vs -12.2 mL/yr per pack per day, p < 0.002). CONCLUSION: There are differences in effects from smoking on lung function between men and women. Lung function recovers faster in women quitters than in men. Women current smokers with airway obstruction experience a greater smoking related decline in lung function than men

    Evaluation of major depression in a routine clinical assessment

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    <p>Abstract</p> <p>Background</p> <p>Major depression is a disorder that significantly worsens a patient's morbidity and mortality. The association of depression and diabetes is well documented and has clinical impact in diabetes treatment's outcome. Patients usually aren't evaluated initially by a psychiatrist, so it is important that non-psychiatrists learn to evaluate major depression and its impact.</p> <p>Conclusions</p> <p>Major depression can and should be evaluated on a routine clinical assessment. Depression's impact on the patients' quality of life, productivity and social interactions is well documented. The initial diagnosis of depression should lead to its prompt treatment, and it has to be emphasized that the incorrect treatment can lead to worsening of the condition, relapses, recurrences or even chronification of major depression.</p

    Acute febrile illness is associated with Rickettsia spp infection in dogs

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    BACKGROUND: Rickettsia conorii is transmitted by Rhipicephalus sanguineus ticks and causes Mediterranean Spotted Fever (MSF) in humans. Although dogs are considered the natural host of the vector, the clinical and epidemiological significance of R. conorii infection in dogs remains unclear. The aim of this prospective study was to investigate whether Rickettsia infection causes febrile illness in dogs living in areas endemic for human MSF. METHODS: Dogs from southern Italy with acute fever (n = 99) were compared with case–control dogs with normal body temperatures (n = 72). Serology and real-time PCR were performed for Rickettsia spp., Ehrlichia canis, Anaplasma phagocytophilum/A. platys and Leishmania infantum. Conventional PCR was performed for Babesia spp. and Hepatozoon spp. Acute and convalescent antibodies to R. conorii, E. canis and A. phagocytophilum were determined. RESULTS: The seroprevalence rates at first visit for R. conorii, E. canis, A. phagocytophilum and L. infantum were 44.8%, 48.5%, 37.8% and 17.6%, respectively. The seroconversion rates for R. conorii, E. canis and A. phagocytophilum were 20.7%, 14.3% and 8.8%, respectively. The molecular positive rates at first visit for Rickettsia spp., E. canis, A. phagocytophilum, A. platys, L. infantum, Babesia spp. and Hepatozoon spp. were 1.8%, 4.1%, 0%, 2.3%, 11.1%, 2.3% and 0.6%, respectively. Positive PCR for E. canis (7%), Rickettsia spp. (3%), Babesia spp. (4.0%) and Hepatozoon spp. (1.0%) were found only in febrile dogs. The DNA sequences obtained from Rickettsia and Babesia PCRs positive samples were 100% identical to the R. conorii and Babesia vogeli sequences in GenBank®, respectively. Febrile illness was statistically associated with acute and convalescent positive R. conorii antibodies, seroconversion to R. conorii, E. canis positive PCR, and positivity to any tick pathogen PCRs. Fourteen febrile dogs (31.8%) were diagnosed with Rickettsia spp. infection based on seroconversion and/or PCR while only six afebrile dogs (12.5%) seroconverted (P = 0.0248). The most common clinical findings of dogs with Rickettsia infection diagnosed by seroconversion and/or PCR were fever, myalgia, lameness, elevation of C-reactive protein, thrombocytopenia and hypoalbuminemia. CONCLUSIONS: This study demonstrates acute febrile illness associated with Rickettsia infection in dogs living in endemic areas of human MSF based on seroconversion alone or in combination with PCR

    Moduli Stabilization and Cosmology of Type IIB on SU(2)-Structure Orientifolds

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    We consider type IIB flux compactifications on six-dimensional SU(2)-structure manifolds with O5- and O7-planes. These six-dimensional spaces allow not only for F_3 and H_3 fluxes but also for F_1 and F_5 fluxes. We derive the four-dimensional N=1 scalar potential for such compactifications and present one explicit example of a fully stabilized AdS vacuum with large volume and small string coupling. We then discuss cosmological aspects of these compactifications and derive several no-go theorems that forbid dS vacua and slow-roll inflation under certain conditions. We also study concrete examples of cosets and twisted tori and find that our no-go theorems forbid dS vacua and slow-roll inflation in all but one of them. For the latter we find a dS critical point with \epsilon numerically zero. However, the point has two tachyons and eta-parameter \eta \approx -3.1.Comment: 35 pages + appendices, LaTeX2e; v2: numerical dS extremum added, typos corrected, references adde
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