37 research outputs found

    LSQ13ddu: a rapidly evolving stripped-envelope supernova with early circumstellar interaction signatures

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    This paper describes the rapidly evolving and unusual supernova LSQ13ddu, discovered by the La Silla-QUEST survey. LSQ13ddu displayed a rapid rise of just 4.8 ± 0.9 d to reach a peak brightness of −19.70 ± 0.02 mag in the LSQgr band. Early spectra of LSQ13ddu showed the presence of weak and narrow HeI features arising from interaction with circumstellar material (CSM). These interaction signatures weakened quickly, with broad features consistent with those seen in stripped-envelope SNe becoming dominant around two weeks after maximum. The narrow HeI velocities are consistent with the wind velocities of luminous blue variables but its spectra lack the typically seen hydrogen features. The fast and bright early light curve is inconsistent with radioactive ⁵⁶Ni powering but can be explained through a combination of CSM interaction and an underlying ⁵⁶Ni decay component that dominates the later time behaviour of LSQ13ddu. Based on the strength of the underlying broad features, LSQ13ddu appears deficient in He compared to standard SNe Ib

    10-Year Resource Utilization and Costs for Cardiovascular Care

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    Background: Cardiovascular disease (CVD) imparts a heavy economic burden on the U.S. health care system. Evidence regarding the long-term costs after comprehensive CVD screening is limited. Objectives: This study calculated 10-year health care costs for 6,814 asymptomatic participants enrolled in MESA (Multi-Ethnic Study of Atherosclerosis), a registry sponsored by the National Heart, Lung, and Blood Institute, National Institutes of Health. Methods: Cumulative 10-year costs for CVD medications, office visits, diagnostic procedures, coronary revascularization, and hospitalizations were calculated from detailed follow-up data. Costs were derived by using Medicare nationwide and zip code–specific costs, inflation corrected, discounted at 3% per year, and presented in 2014 U.S. dollars. Results: Risk factor prevalence increased dramatically and, by 10 years, diabetes, hypertension, and dyslipidemia was reported in 19%, 57%, and 53%, respectively. Self-reported symptoms (i.e., chest pain or shortness of breath) were common (approximately 40% of enrollees). At 10 years, approximately one-third of enrollees reported having an echocardiogram or exercise test, whereas 7% underwent invasive coronary angiography. These utilization patterns resulted in 10-year health care costs of 23,142.ThelargestproportionofcostswasassociatedwithCVDmedicationuse(7823,142. The largest proportion of costs was associated with CVD medication use (78%). Approximately 2 of every 10werespentforoutpatientvisitsanddiagnostictestingamongtheelderly,obese,thosewithahighsensitivityCreactiveproteinlevel3˘e3mg/l,orcoronaryarterycalciumscore(CACS)400.Costsvariedwidelyfrom3˘c10 were spent for outpatient visits and diagnostic testing among the elderly, obese, those with a high-sensitivity C-reactive protein level \u3e3 mg/l, or coronary artery calcium score (CACS) ≥400. Costs varied widely from \u3c7,700 for low-risk (Framingham risk score \u3c6%, 0 CACS, and normal glucose measurements at baseline) to \u3e35,800forhighrisk(personswithdiabetes,Framinghamriskscore2035,800 for high-risk (persons with diabetes, Framingham risk score ≥20%, or CACS ≥400) subgroups. Among high-risk enrollees, CVD costs accounted for 74 million of the $155 million consumed by MESA participants. Conclusions: Longitudinal patterns of health care resource use after screening revealed new evidence on the economic burden of treatment and testing patterns not previously reported. Maintenance of a healthy population has the potential to markedly reduce the economic burden of CVD among asymptomatic individuals

    The carbon-rich type Ic supernova 2016adj in the iconic dust lane of Centaurus A: signatures of interaction with circumstellar hydrogen?

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    We present a comprehensive data set of supernova (SN) 2016adj located within the central dust lane of Centaurus A. SN 2016adj is significantly reddened and after correcting the peak apparent BB-band magnitude (mB=17.48±0.05m_B = 17.48\pm0.05) for Milky Way reddening and our inferred host-galaxy reddening parameters (i.e., RVhost=5.7±0.7R_{V}^{host} = 5.7\pm0.7 and AVhost=6.3±0.2A_{V}^{host} = 6.3\pm0.2), we estimate it reached a peak absolute magnitude of MB18M_B \sim -18. Detailed inspection of the optical/NIR spectroscopic time-series reveals a carbon-rich SN Ic and not a SN Ib/IIb as previously suggested in the literature. The NIR spectra shows prevalent carbon-monoxide formation occurring already by +41 days past BB-band maximum, which is 11\approx 11 days earlier than previously reported in the literature for this object. Interestingly around two months past maximum, the NIR spectrum of SN~2016adj begins to exhibit H features, with a +97~d medium resolution spectrum revealing both Paschen and Bracket lines with absorption minima of 2000\sim 2000 km/s, full-width-half-maximum emission velocities of 1000\sim 1000 km/s, and emission line ratios consistent with a dense emission region. We speculate these attributes are due to circumstellar interaction (CSI) between the rapidly expanding SN ejecta and a H-rich shell of material formed during the pre-SN phase. A bolometric light curve is constructed and a semi-analytical model fit suggests the supernova synthesized 0.5 solar masses of 56^{56}Ni and ejected 4.2 solar masses of material, though these values should be approached with caution given the large uncertainties associated with the adopted reddening parameters, possible CSI contamination, and known light echo emission. Finally, inspection of Hubble Space Telescope archival data yielded no progenitor detection.Comment: Submitted to A&A, comments are welcom

    Consequences of Covid-19 on the Social Isolation of the Chinese Economy: Accounting for the Role of Reduction in Carbon Emissions

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    The main contribution of the present study to the energy literature is linked to the interaction between economic growth and pollution emission amidst globalization. Unlike other studies, this research explores the effect of economic and social isolation as a dimension of globalization. This allows underpinning the effects on the Chinese economic development of the isolation phenomenon as a consequence of coronavirus (COVID-19). To this end, annual time frequency data is used to achieve the hypothesized claims. The study resolutions include (i) The existence of a long-run equilibrium bond between the outlined variables (ii) The long-run estimates suggest that the Chinese economy over the investigated period, is inelastic to pollutant–driven economic growth as reported by the dynamic ordinary least squares, fully modified ordinary least squares and canonical regressions with a magnitude of 0.09%. (iii) The Chinese isolation is less responsive to its economic growth while the country political willpower is elastic as demonstrated by current government commitment to dampen the effect of the COVID-19 pandemic. This is marked by the aggressive response on the government officials resolute by flattening the exponential impact of the pandemic. Based on these robust results some far-reaching policy implication(s) are underlined in the concluding remark section

    LSQ13ddu: a rapidly evolving stripped-envelope supernova with early circumstellar interaction signatures

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    This paper describes the rapidly evolving and unusual supernova LSQ13ddu, discovered by the La Silla-QUEST survey. LSQ13ddu displayed a rapid rise of just 4.8 +/- 0.9 d to reach a peak brightness of -19.70 +/- 0.02 mag in the LSQgr band. Early spectra of LSQ13ddu showed the presence of weak and narrow He I features arising from interaction with circumstellar material (CSM). These interaction signatures weakened quickly, with broad features consistent with those seen in stripped-envelope SNe becoming dominant around two weeks after maximum. The narrow He I velocities are consistent with the wind velocities of luminous blue variables but its spectra lack the typically seen hydrogen features. The fast and bright early light curve is inconsistent with radioactive Ni-56 powering but can be explained through a combination of CSM interaction and an underlying Ni-56 decay component that dominates the later time behaviour of LSQ13ddu. Based on the strength of the underlying broad features, LSQ13ddu appears deficient in He compared to standard SNe Ib

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
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