8,691 research outputs found

    Real-time Analysis and Selection Biases in the Supernova Legacy Survey

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    The Supernova Legacy Survey (SNLS) has produced a high-quality, homogeneous sample of Type Ia supernovae (SNe Ia) out to redshifts greater than z=1. In its first four years of full operation (to June 2007), the SNLS discovered more than 3000 transient candidates, 373 of which have been confirmed spectroscopically as SNe Ia. Use of these SNe Ia in precision cosmology critically depends on an analysis of the observational biases incurred in the SNLS survey due to the incomplete sampling of the underlying SN Ia population. This paper describes our real-time supernova detection and analysis procedures, and uses detailed Monte Carlo simulations to examine the effects of Malmquist bias and spectroscopic sampling. Such sampling effects are found to become apparent at z~0.6, with a significant shift in the average magnitude of the spectroscopically confirmed SN Ia sample towards brighter values for z>0.75. We describe our approach to correct for these selection biases in our three-year SNLS cosmological analysis (SNLS3), and present a breakdown of the systematic uncertainties involved.Comment: Accepted for publication in A

    Resistance training volume, energy balance and weight management: Rationale and design of a 9 month trial

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    The increased prevalence of obesity and the lack of treatment success both argue for the design and evaluation of strategies to prevent the development of overweight and obesity. To date, the role of resistance training (RT) in this regard is largely unexplored. RT may be effective for weight management as a result of increased fat-free mass (FFM), which may result in increased resting metabolic rate and increased physical activity energy expenditure. However, the literature relative to the efficacy of RT protocols recommended for healthy adults to alter the aforementioned parameters is inconsistent or inadequately evaluated. We will conduct a 9 month randomized controlled efficacy trial to compare changes in body composition (fat mass, FFM, % body fat) and energy balance in response to 2 volumes of RT (1 vs. 3 sets vs. non-exercise control) both at the completion of training (9 months) and 1 year later (body composition). This investigation will be conducted in a sample of healthy, normal and overweight, sedentary, young adult men and women; a group at high risk for development of overweight and obesity. Our results will provide information relative to the minimum volume of RT that may be associated with body weight/fat gain which may inform the development of guidelines for RT to prevent weight gain or to alter body composition

    ‘Everything’s from the inside out with PCOS’:exploring women’s experiences of living with Polycystic Ovary Syndrome (PCOS) and co-morbidities through Skype™ interviews

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    Polycystic ovary syndrome is an endocrine disorder affecting 1 in 10 women. Women with polycystic ovary syndrome can experience co-morbidities, including depressive symptoms. This research explores the experience of living with polycystic ovary syndrome and co-morbidities. Totally, 10 participants with polycystic ovary syndrome took part in Skypeâ„¢ interviews and analysed using thematic analysis. Four themes emerged from the data: change (to life plans and changing nature of condition); support (healthcare professionals, education and relationships); co-morbidities (living with other conditions and depression, self-harm and suicidal ideation) and identity (feminine identity and us and them). The findings highlight the need for screening of women with polycystic ovary syndrome for depressive disorders

    An Efficient Approach to Obtaining Large Numbers of Distant Supernova Host Galaxy Redshifts

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    We use the wide-field capabilities of the 2dF fibre positioner and the AAOmega spectrograph on the Anglo-Australian Telescope (AAT) to obtain redshifts of galaxies that hosted supernovae during the first three years of the Supernova Legacy Survey (SNLS). With exposure times ranging from 10 to 60 ksec per galaxy, we were able to obtain redshifts for 400 host galaxies in two SNLS fields, thereby substantially increasing the total number of SNLS supernovae with host galaxy redshifts. The median redshift of the galaxies in our sample that hosted photometrically classified Type Ia supernovae (SNe Ia) is 0.77, which is 25% higher than the median redshift of spectroscopically confirmed SNe Ia in the three-year sample of the SNLS. Our results demonstrate that one can use wide-field fibre-fed multi-object spectrographs on 4m telescopes to efficiently obtain redshifts for large numbers of supernova host galaxies over the large areas of sky that will be covered by future high-redshift supernova surveys, such as the Dark Energy Survey.Comment: 22 pages, 4 figures, accepted for publication in PAS

    Improved plasma startup in the Tara central cell

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    A Chronic Care Model Program Incorporating Group Office Visits for Obesity Treatment in Primary Care

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    Background. Obesity is a chronic disease of epidemic proportions. Primary care providers are on the front line of diagnosing and treating obesity and need better tools to deliver top-notch obesity care. Methods. A pilot randomized trial was conducted to test a chronic care model (CCM) program for obesity compared to usual care. Primary care patients, 18 years and older, with a body mass index (BMI) between 27 and 45 were enrolled. Sixteen weekly 90-minute group office visits were structured with the first 30 minutes encompassing individualized clinical assessments and the final 60 minutes containing the group-based standardized intensive lifestyle training. The primary outcome was weight change at 16 weeks. Secondary outcomes were weight change at 24 weeks, change in diet and physical activity behaviors, self-efficacy for weight control behaviors, and physiologic markers of cardiovascular risk at 16 and 24 weeks. Results. The participants (19 in the active arm and 10 in the control arm) were 49.8 ± 11.5 years old (mean ± SD), 97% women, 55% white, and 41% black. Weight change in the control arm at week 16 was 0.25+ 2.21 kg (mean + SD) and that for the active arm was -5.74 + 4.50 kg (n=16). The difference between the two arms was significant (p = 0.0002). Both the intent-to-treat analysis using the last observation carried forward approach and the analysis including completers only provided similar siginificant results. Conclusions. This study demonstrated that a CCM program incorporating group office visits was feasible and effective for obesity treatment in primary care settings

    A Randomized, Controlled, Supervised, Excerise Trial in Young Overweight Men and Women: The Midwest Exercise Trial II (MET2)

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    We evaluated weight loss response to 16 months of supervised exercise (45 minutes/d, 5 d/wk, 75% heart-rate-reserve) in sedentary, overweight/obese participants without energy restriction in the Midwest Exercise Trial (MET1). Results indicated men lost weight, women did not. The gender differences were associated with differences in the energy expenditure of exercise (EEEx) (men = 667 ± 116; women = 439 ± 88 kcal/session) when exercise was prescribed by frequency, intensity and duration. MET2 is a randomized control trial designed and powered to examine differences in weight loss and gender in response to EEEx for men and women of 400 or 600 kcal/session, 5d/wk, for 10 months without energy restriction. One hundred forty one participants will be randomized to 1 of 2 exercise groups or a non-exercise control. EEEx will be verified by indirect calorimetry monthly during the intervention. This study will evaluate: (1) the weight change response to two levels of EEEx versus non-exercise control; (2) gender differences in weight response to two levels of EEEx; (3) potential compensatory changes in energy intake and/or daily physical activity that may explain the observed weight changes. Results from this study may impact how exercise is prescribed for weight loss and prevention of weight regain and may clarify if men and women differ in response to exercise

    The progenitor and early evolution of the Type IIb SN 2016gkg

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    We report initial observations and analysis on the Type IIb SN~2016gkg in the nearby galaxy NGC~613. SN~2016gkg exhibited a clear double-peaked light curve during its early evolution, as evidenced by our intensive photometric follow-up campaign. SN~2016gkg shows strong similarities with other Type IIb SNe, in particular with respect to the \he~emission features observed in both the optical and near infrared. SN~2016gkg evolved faster than the prototypical Type~IIb SN~1993J, with a decline similar to that of SN~2011dh after the first peak. The analysis of archival {\it Hubble Space Telescope} images indicate a pre-explosion source at SN~2016gkg's position, suggesting a progenitor star with a ∼\simmid F spectral type and initial mass 15−2015-20\msun, depending on the distance modulus adopted for NGC~613. Modeling the temperature evolution within 5 days5\,\rm{days} of explosion, we obtain a progenitor radius of ∼ 48−124\sim\,48-124\rsun, smaller than that obtained from the analysis of the pre-explosion images (240−320240-320\rsun).Comment: 7 pages, 5 figures. Submitted to ApJ Letter

    Weight management by phone conference call: A comparision with a traditional face-to-face clinic. Rationale and design for a randomized equivalence trial

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    State-of-the-art treatment for weight management consists of a behavioral intervention to facilitate decreased energy intake and increased physical activity. These interventions are typically delivered face-to-face (FTF) by a health educator to a small group of participants. There are numerous barriers to participation in FTF clinics including availability, scheduling, the expense and time required to travel to the clinic site, and possible need for dependent care. Weight management clinics delivered by conference call have the potential to diminish or eliminate these barriers. The conference call approach may also reduce burden on providers, who could conduct clinic groups from almost any location without the expenses associated with maintaining FTF clinic space. A randomized trial will be conducted in 395 overweight/obese adults (BMI 25–39.9 kg/m2) to determine if weight loss (6 months) and weight maintenance (12 months) are equivalent between weight management interventions utilizing behavioral strategies and pre-packaged meals delivered by either a conference call or the traditional FTF approach. The primary outcome, body weight, will be assessed at baseline, 6, 12 and 18 months. Secondary outcomes including waist circumference, energy and macronutrient intake, and physical activity and will be assessed on the same schedule. In addition, a cost analysis and extensive process evaluation will be completed
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