3,763 research outputs found

    Infrared Emission from Supernova Remnants: Formation and Destruction of Dust

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    We review the observations of dust emission in supernova rem- nants (SNRs) and supernovae (SNe). Theoretical calculations suggest that SNe, particularly core-collapse, should make significant quantities of dust, perhaps as much as a solar mass. Observations of extragalactic SNe have yet to find anywhere near this amount, but this may be the result of observa- tional limitations. SN 1987A, in the process of transitioning from a SN to an SNR, does show signs of a significant amount of dust forming in its ejecta, but whether this dust will survive the passage of the reverse shock to be injected into the ISM is unknown. IR observations of SNRs have not turned up significant quantities of dust, and the dust that is observed is generally swept-up by the forward shock, rather than created in the ejecta. Because the shock waves also destroy dust in the ISM, we explore the question of whether SNe might be net destroyers, rather than net creators of dust in the universe.Comment: Published in the Springer Handbook of Supernova

    Polymorphisms in PTK2 are associated with skeletal muscle specific force: an independent replication study

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    Purpose The aim of the study was to investigate two single nucleotide polymorphisms (SNP) in PTK2 for associations with human muscle strength phenotypes in healthy men. Methods Measurement of maximal isometric voluntary knee extension (MVCKE) torque, net MVCKE torque and vastus lateralis (VL) specific force, using established techniques, was completed on 120 Caucasian men (age = 20.6 ± 2.3 year; height = 1.79 ± 0.06 m; mass = 75.0 ± 10.0 kg; mean ± SD). All participants provided either a blood (n = 96) or buccal cell sample, from which DNA was isolated and genotyped for the PTK2 rs7843014 A/C and rs7460 A/T SNPs using real-time polymerase chain reaction. Results Genotype frequencies for both SNPs were in Hardy–Weinberg equilibrium (X 2 ≤ 1.661, P ≥ 0.436). VL specific force was 8.3% higher in rs7843014 AA homozygotes than C-allele carriers (P = 0.017) and 5.4% higher in rs7460 AA homozygotes than T-allele carriers (P = 0.029). No associations between either SNP and net MVCKE torque (P ≥ 0.094) or peak MVCKE torque (P ≥ 0.107) were observed. Conclusions These findings identify a genetic contribution to the inter-individual variability within muscle specific force and provides the first independent replication, in a larger Caucasian cohort, of an association between these PTK2 SNPs and muscle specific force, thus extending our understanding of the influence of genetic variation on the intrinsic strength of muscle.Published versio

    Objective responses to first-line neoadjuvant carboplatin-paclitaxel regimens for ovarian, fallopian tube, or primary peritoneal carcinoma (ICON8): post-hoc exploratory analysis of a randomised, phase 3 trial

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    Background: Platinum-based neoadjuvant chemotherapy followed by delayed primary surgery (DPS) is an established strategy for women with newly diagnosed, advanced-stage epithelial ovarian cancer. Although this therapeutic approach has been validated in randomised, phase 3 trials, evaluation of response to neoadjuvant chemotherapy using Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST), and cancer antigen 125 (CA125) has not been reported. We describe RECIST and Gynecologic Cancer InterGroup (GCIG) CA125 responses in patients receiving platinum-based neoadjuvant chemotherapy followed by DPS in the ICON8 trial. / Methods: ICON8 was an international, multicentre, randomised, phase 3 trial done across 117 hospitals in the UK, Australia, New Zealand, Mexico, South Korea, and Ireland. The trial included women aged 18 years or older with an Eastern Cooperative Oncology Group performance status of 0–2, life expectancy of more than 12 weeks, and newly diagnosed International Federation of Gynecology and Obstetrics (FIGO; 1988) stage IC–IIA high-grade serous, clear cell, or any poorly differentiated or grade 3 histological subtype, or any FIGO (1988) stage IIB–IV epithelial cancer of the ovary, fallopian tube, or primary peritoneum. Patients were randomly assigned (1:1:1) to receive intravenous carboplatin (area under the curve [AUC]5 or AUC6) and intravenous paclitaxel (175 mg/m2 by body surface area) on day 1 of every 21-day cycle (control group; group 1); intravenous carboplatin (AUC5 or AUC6) on day 1 and intravenous dose-fractionated paclitaxel (80 mg/m2 by body surface area) on days 1, 8, and 15 of every 21-day cycle (group 2); or intravenous dose-fractionated carboplatin (AUC2) and intravenous dose-fractionated paclitaxel (80 mg/m2 by body surface area) on days 1, 8, and 15 of every 21-day cycle (group 3). The maximum number of cycles of chemotherapy permitted was six. Randomisation was done with a minimisation method, and patients were stratified according to GCIG group, disease stage, and timing and outcome of cytoreductive surgery. Patients and clinicians were not masked to group allocation. The scheduling of surgery and use of neoadjuvant chemotherapy were determined by local multidisciplinary case review. In this post-hoc exploratory analysis of ICON8, progression-free survival was analysed using the landmark method and defined as the time interval between the date of pre-surgical planning radiological tumour assessment to the date of investigator-assessed clinical or radiological progression or death, whichever occurred first. This definition is different from the intention-to-treat primary progression-free survival analysis of ICON8, which defined progression-free survival as the time from randomisation to the date of first clinical or radiological progression or death, whichever occurred first. We also compared the extent of surgical cytoreduction with RECIST and GCIG CA125 responses. This post-hoc exploratory analysis includes only women recruited to ICON8 who were planned for neoadjuvant chemotherapy followed by DPS and had RECIST and/or GCIG CA125-evaluable disease. ICON8 is closed for enrolment and follow-up, and registered with ClinicalTrials.gov, NCT01654146. / Findings: Between June 6, 2011, and Nov 28, 2014, 1566 women were enrolled in ICON8, of whom 779 (50%) were planned for neoadjuvant chemotherapy followed by DPS. Median follow-up was 29·5 months (IQR 15·6–54·3) for the neoadjuvant chemotherapy followed by DPS population. Of 564 women who had RECIST-evaluable disease at trial entry, 348 (62%) had a complete or partial response. Of 727 women who were evaluable by GCIG CA125 criteria at the time of diagnosis, 610 (84%) had a CA125 response. Median progression-free survival was 14·4 months (95% CI 9·2–28·0; 297 events) for patients with a RECIST complete or partial response and 13·3 months (8·1–20·1; 171 events) for those with RECIST stable disease. Median progression-free survival for women with a GCIG CA125 response was 13·8 months (95% CI 8·8–23·4; 544 events) and 9·7 months (5·8–14·5; 111 events) for those without a GCIG CA125 response. Complete cytoreduction (R0) was achieved in 187 (56%) of 335 women with a RECIST complete or partial response and 73 (42%) of 172 women with RECIST stable disease. Complete cytoreduction was achieved in 290 (50%) of 576 women with a GCIG CA125 response and 30 (30%) of 101 women without a GCIG CA125 response. / Interpretation: The RECIST-defined radiological response rate was lower than that frequently quoted to patients in the clinic. RECIST and GCIG CA125 responses to neoadjuvant chemotherapy for epithelial ovarian cancer should not be used as individual predictive markers to stratify patients who are likely to benefit from DPS, but instead used in conjunction with the patient's clinical capacity to undergo cytoreductive surgery. A patient should not be denied surgery based solely on the lack of a RECIST or GCIG CA125 response. / Funding: Cancer Research UK, UK Medical Research Council, Health Research Board in Ireland, Irish Cancer Society, and Cancer Australia

    Exploring the equity of GP practice prescribing rates for selected coronary heart disease drugs: a multiple regression analysis with proxies of healthcare need

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    Background There is a small, but growing body of literature highlighting inequities in GP practice prescribing rates for many drug therapies. The aim of this paper is to further explore the equity of prescribing for five major CHD drug groups and to explain the amount of variation in GP practice prescribing rates that can be explained by a range of healthcare needs indicators (HCNIs). Methods The study involved a cross-sectional secondary analysis in four primary care trusts (PCTs 1–4) in the North West of England, including 132 GP practices. Prescribing rates (average daily quantities per registered patient aged over 35 years) and HCNIs were developed for all GP practices. Analysis was undertaken using multiple linear regression. Results Between 22–25% of the variation in prescribing rates for statins, beta-blockers and bendrofluazide was explained in the multiple regression models. Slightly more variation was explained for ACE inhibitors (31.6%) and considerably more for aspirin (51.2%). Prescribing rates were positively associated with CHD hospital diagnoses and procedures for all drug groups other than ACE inhibitors. The proportion of patients aged 55–74 years was positively related to all prescribing rates other than aspirin, where they were positively related to the proportion of patients aged >75 years. However, prescribing rates for statins and ACE inhibitors were negatively associated with the proportion of patients aged >75 years in addition to the proportion of patients from minority ethnic groups. Prescribing rates for aspirin, bendrofluazide and all CHD drugs combined were negatively associated with deprivation. Conclusion Although around 25–50% of the variation in prescribing rates was explained by HCNIs, this varied markedly between PCTs and drug groups. Prescribing rates were generally characterised by both positive and negative associations with HCNIs, suggesting possible inequities in prescribing rates on the basis of ethnicity, deprivation and the proportion of patients aged over 75 years (for statins and ACE inhibitors, but not for aspirin)

    Tumor markers in breast cancer - European Group on Tumor Markers recommendations

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    Recommendations are presented for the routine clinical use of serum and tissue-based markers in the diagnosis and management of patients with breast cancer. Their low sensitivity and specificity preclude the use of serum markers such as the MUC-1 mucin glycoproteins ( CA 15.3, BR 27.29) and carcinoembryonic antigen in the diagnosis of early breast cancer. However, serial measurement of these markers can result in the early detection of recurrent disease as well as indicate the efficacy of therapy. Of the tissue-based markers, measurement of estrogen and progesterone receptors is mandatory in the selection of patients for treatment with hormone therapy, while HER-2 is essential in selecting patients with advanced breast cancer for treatment with Herceptin ( trastuzumab). Urokinase plasminogen activator and plasminogen activator inhibitor 1 are recently validated prognostic markers for lymph node-negative breast cancer patients and thus may be of value in selecting node-negative patients that do not require adjuvant chemotherapy. Copyright (C) 2005 S. Karger AG, Basel

    An extremely powerful long-lived superluminal ejection from the black hole MAXI J1820+070

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    Black holes in binary systems execute patterns of outburst activity where two characteristic X-ray states are associated with different behaviours observed at radio wavelengths. The hard state is associated with radio emission indicative of a continuously replenished, collimated, relativistic jet, whereas the soft state is rarely associated with radio emission, and never continuously, implying the absence of a quasi-steady jet. Here we report radio observations of the black hole transient MAXI J1820++070 during its 2018 outburst. As the black hole transitioned from the hard to soft state we observed an isolated radio flare, which, using high angular resolution radio observations, we connect with the launch of bi-polar relativistic ejecta. This flare occurs as the radio emission of the core jet is suppressed by a factor of over 800. We monitor the evolution of the ejecta over 200 days and to a maximum separation of 10'', during which period it remains detectable due to in-situ particle acceleration. Using simultaneous radio observations sensitive to different angular scales we calculate an accurate estimate of energy content of the approaching ejection. This energy estimate is far larger than that derived from state transition radio flare, suggesting a systematic underestimate of jet energetics

    Transposing tirtha: Understanding religious reforms and locative piety in early modern Hinduism

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    The paper deals with a historical and hitherto obscure case of de-commercialisation of sacred geography of India. Sahajanand Swami, an eighteenth century religious leader from Gujarat who became popular as Bhagwan Swaminarayan took an initiative to eliminate corruption in Dwarka, one of the most sacred destination in Hindu imagination. He also attempted to transpose the piety of Dwarka and recreate a parallel religious experience at Vadtal, an important site in Swaminarayan Hinduism. This process of making sacred sites more egalitarian is classified here as a 'religious reform'. The paper assesses this bivalent pursuit as an institutional reform within religion as well as a religious process in the context of piety, authority and orthodoxy. Through the example of Sahajanand Swami, it is argued to calibrate the colonial paradigm of reform that was largely contextual to social issues and western thought and failed to appreciate the religious reforms of that era. By constructing a nuanced typology of 'religious reform' distinct from 'social reforms', the paper eventually calls for a reassessment of religious figures who have significantly contributed in reforming the Hindu tradition in the medieval and modern era

    Measurement of Exclusive B Decays to Final States Containing a Charmed Baryon

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    Using data collected by the CLEO detector in the Upsilon(4S) region, we report new measurements of the exclusive decays of B mesons into final states of the type Lambda_c^+ p-bar n(pi), where n=0,1,2,3. We find signals in modes with one, two and three pions and an upper limit for the two body decay Lambda_c^+ pbar. We also make the first measurements of exclusive decays of B mesons to Sigma_c p-bar n(pi), where n=0,1,2. We find signals in modes with one and two pions and an upper limit for the two body decay Sigma_c p-bar. Measurements of these modes shed light on the mechanisms involved in B decays to baryons.Comment: 11 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, submitted to PR

    Measurement of the Masses and Widths of the Sigma_c^++ and Sigma_c^0 Charmed Baryons

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    Using data recorded by the CLEO II and CLEO II.V detector configurations at CESR, we report new measurements of the masses of the Sigma_c^{++} and Sigma_c^0 charmed baryons, and the first measurements of their intrinsic widths. We find M(Sigma_c^{++}) - M(Lambda_c^+) = 167.4 +- 0.1 +- 0.2 MeV, Gamma(Sigma_c^{++}) = 2.3 +- 0.2 +- 0.3 MeV, and M(Sigma_c^0) - M(Lambda_c^+) = 167.2 +- 0.1 +- 0.2 MeV, Gamma(Sigma_c^0) = 2.5 +- 0.2 +- 0.3 MeV, where the uncertainties are statistical and systematic, respectively.Comment: 9 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, submitted to PRD, Rapid Communications. Reference [13] correcte
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