120 research outputs found

    Far-Infrared Properties of Spitzer-selected Luminous Starbursts

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    We present SHARC-2 350 micron data on 20 luminous z ~ 2 starbursts with S(1.2mm) > 2 mJy from the Spitzer-selected samples of Lonsdale et al. and Fiolet et al. All the sources were detected, with S(350um) > 25 mJy for 18 of them. With the data, we determine precise dust temperatures and luminosities for these galaxies using both single-temperature fits and models with power-law mass--temperature distributions. We derive appropriate formulae to use when optical depths are non-negligible. Our models provide an excellent fit to the 6um--2mm measurements of local starbursts. We find characteristic single-component temperatures T1 ~ 35.5+-2.2 K and integrated infrared (IR) luminosities around 10^(12.9+-0.1) Lsun for the SWIRE-selected sources. Molecular gas masses are estimated at 4 x 10^(10) Msun, assuming kappa(850um)=0.15 m^2/kg and a submillimeter-selected galaxy (SMG)-like gas-to-dust mass ratio. The best-fit models imply >~2 kpc emission scales. We also note a tight correlation between rest-frame 1.4 GHz radio and IR luminosities confirming star formation as the predominant power source. The far-IR properties of our sample are indistinguishable from the purely submillimeter-selected populations from current surveys. We therefore conclude that our original selection criteria, based on mid-IR colors and 24 um flux densities, provides an effective means for the study of SMGs at z ~ 1.5--2.5.Comment: 13 pages, 4 figures, edited to match published version in ApJ 717, 29-39 (2010

    Choline and contribution to normal liver function of the foetus and exclusively breastfed infants: evaluation of a health claim pursuant to Article 14 of Regulation (EC) No 1924/2006

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    Following an application from Procter & Gamble BV pursuant to Article 14 of Regulation (EC) No 1924/2006 via the Competent Authority of Belgium, the Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim related to choline and contribution to normal liver function of the foetus and exclusively breastfed infant. The scope of the application was proposed to fall under a health claim referring to children's development and health. The Panel considers that choline is sufficiently characterised. The claimed effect proposed by the applicant is contribution ‘to normal foetal and infant development, especially liver’. The proposed target population is ‘unborn fetuses and breastfed infants’. Choline is involved in the structure of cell membranes, cell signalling, metabolism and transport of lipids and cholesterol and neurotransmitter synthesis. Although choline can be synthesised de novo by the human body, depletion-repletion studies in humans show that low choline intake leads to liver dysfunction and muscle damage, which are reverted by the administration of dietary choline. For these functions, de novo synthesis of choline by the human body is insufficient and choline must be obtained from dietary sources. No human studies have addressed the effect of low maternal dietary choline intake on liver function in the fetus or exclusively breastfed infants. However, the Panel considers that the biological role of choline in normal liver function and dietary choline being essential for the function applies to all ages, including fetus and infants. The Panel concludes that a cause and effect relationship has been established between the intake of choline by pregnant and lactating women and contribution to normal liver function of the fetus and exclusively breastfed infants

    Appethyl® and reduction of body weight: evaluation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006

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    Following an application from Greenleaf Medical AB, submitted for authorisation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of Sweden, the EFSA Panel on Nutrition, Novel Foods and Food allergens (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim related to Appethyl® and reduction of body weight. Appethyl® is an aqueous extract from spinach leaves standardised by the manufacturing process and its lipase/colipase inhibition capacity in vitro. The Panel considers that the food is sufficiently characterised. A reduction in body weight is a beneficial physiological effect for overweight/obese individuals. The applicant identified a total of three human intervention studies that investigated the effects of Appethyl® on body weight as being pertinent to the claim. In weighing the evidence, the Panel took into account that Appethyl® (5 g/day for 12 weeks) had no effect on body weight as compared to placebo under minimal dietary counselling and moderate physical activity, and that no beneficial physiological effects are to be expected for the target population of overweight/obese individuals from the weight loss that could be attributed to the intervention with Appethyl® under predefined energy restriction and moderate physical activity. The Panel also considered that the effect of Appethyl® (5 g/day for 24 weeks) on body weight maintenance after initial weight loss shown in one study has not been replicated in different settings, which questions the external validity of the results, and that no evidence was provided for a plausible mechanism by which daily consumption of Appethyl® could exert a sustained effect on body weight in humans. The Panel concludes that a cause-and-effect relationship has not been established between the consumption of Appethyl® and a reduction of body weight under the conditions of use proposed by the applicant

    A 158 Micron [CII] Line Survey of Galaxies at z ~ 1 to 2: An Indicator of Star Formation in the Early Universe

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    We have detected the 158 {\mu}m [CII] line from 12 galaxies at z~1-2. This is the first survey of this important starformation tracer at redshifts covering the epoch of maximum star-formation in the Universe and quadruples the number of reported high z [CII] detections. The line is very luminous, between <0.024-0.65% of the far-infrared continuum luminosity of our sources, and arises from PDRs on molecular cloud surfaces. An exception is PKS 0215+015, where half of the [CII] emission could arise from XDRs near the central AGN. The L[CII] /LFIR ratio in our star-formation-dominated systems is ~8 times larger than that of our AGN-dominated systems. Therefore this ratio selects for star-formation-dominated systems. Furthermore, the L[CII]/LFIR and L[CII]/L(CO(1-0)) ratios in our starforming galaxies and nearby starburst galaxies are the same, so that luminous starforming galaxies at earlier epochs (z~1-2) appear to be scaled up versions of local starbursts entailing kilo-parsec-scale starbursts. Most of the FIR and [CII] radiation from our AGN-dominated sample (excepting PKS 0215+015) also arises from kpc scale starformation, but with far-UV radiation fields ~8 times more intense than in our star-formation-dominated sample. We speculate that the onset of AGN activity stimulates large-scale star-formation activity within AGN-dominated systems. This idea is supported by the relatively strong [OIII] line emission, indicating very young stars, that was recently observed in high z composite AGN/starburst systems. Our results confirm the utility of the [CII] line, and in particular, the L[CII]/L(FIR) and L[CII]/LCO(1-0) ratios as a tracers of star-formation in galaxies at high redshifts.Comment: 33 pages, 5 figure

    The Herschel Multi-tiered Extragalactic Survey: HerMES

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    The Herschel Multi-tiered Extragalactic Survey, HerMES, is a legacy program designed to map a set of nested fields totalling ~380 deg^2. Fields range in size from 0.01 to ~20 deg^2, using Herschel-SPIRE (at 250, 350 and 500 \mu m), and Herschel-PACS (at 100 and 160 \mu m), with an additional wider component of 270 deg^2 with SPIRE alone. These bands cover the peak of the redshifted thermal spectral energy distribution from interstellar dust and thus capture the re-processed optical and ultra-violet radiation from star formation that has been absorbed by dust, and are critical for forming a complete multi-wavelength understanding of galaxy formation and evolution. The survey will detect of order 100,000 galaxies at 5\sigma in some of the best studied fields in the sky. Additionally, HerMES is closely coordinated with the PACS Evolutionary Probe survey. Making maximum use of the full spectrum of ancillary data, from radio to X-ray wavelengths, it is designed to: facilitate redshift determination; rapidly identify unusual objects; and understand the relationships between thermal emission from dust and other processes. Scientific questions HerMES will be used to answer include: the total infrared emission of galaxies; the evolution of the luminosity function; the clustering properties of dusty galaxies; and the properties of populations of galaxies which lie below the confusion limit through lensing and statistical techniques. This paper defines the survey observations and data products, outlines the primary scientific goals of the HerMES team, and reviews some of the early results.Comment: 23 pages, 17 figures, 9 Tables, MNRAS accepte

    Colchicine and diabetes in patients with chronic coronary artery disease: insights from the LoDoCo2 randomized controlled trial

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    IntroductionDespite optimal treatment, patients with chronic coronary artery disease (CAD) and diabetes mellitus (DM) are at high risk of cardiovascular events, emphasizing the need for new treatment options. The Low-Dose Colchicine 2 (LoDoCo2) trial demonstrated that colchicine reduces cardiovascular risk in patients with chronic CAD. This analysis determines the efficacy of colchicine in patients with chronic CAD and DM as well as the effect of colchicine on the development of new-onset type 2 diabetes mellitus (T2DM).MethodsThe LoDoCo2 trial randomized 5,522 patients to placebo or colchicine 0.5 mg once daily, with a median follow-up of 28.6 months. The primary composite endpoint was cardiovascular death, spontaneous myocardial infarction, ischemic stroke, or ischemia-driven revascularization. The effect of its treatment in patients with and without DM was evaluated by including an interaction term in the model.ResultsA total of 1,007 participants (18.2%) had T2DM at baseline. The adjusted hazard ratio (HR) [(95% confidence interval (CI)] for the primary endpoint in the T2DM group was 1.52 (1.15–2.01, p &lt; 0.01) compared with the group without T2DM. The HR for the treatment effect on the primary endpoint was 0.87 (0.61–1.25) in participants with T2DM and 0.64 (0.51–0.80) in participants without diabetes (pinteraction = 0.14). The incidence of new-onset T2DM was 1.5% (34 out of 2,270) in the colchicine group and 2.2% (49 out of 2,245) in the placebo group (p = 0.10).DiscussionIn conclusion, based on the current evidence, the beneficial effects of colchicine on cardiovascular endpoints are consistent regardless of DM status. The potential benefits of colchicine in preventing new-onset DM need further investigation. These findings are only hypothesis-generating and require larger prospective trials to confirm the results

    Application of prospect theory to management decisions under risk on construction projects

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    Working on a construction project requires making important decisions quickly and frequently. Most of these decisions are made under risk in that the outcomes are not known, but their probabilities and impacts can be estimated, however imprecisely. Deciding to pave, given temperature predictions, is an example of such a decision. When the impacts are aggregated, they can represent a non-negligible amount compared to project budgets. Understanding project leaders’ behaviour when they make such decisions under risks may create opportunities to avoid future losses that result from suboptimal choices. As those decisions are numerous on a construction project, it might be difficult for the project leaders to always make the best choice. By using a questionnaire referring to potential construction project situations, this study shows how some behavioural tendencies can influence the choices of construction leaders. This paper mainly focuses on one aspect of the study, which is the impact of the certainty effect on projects leaders’ decision making. It demonstrates how project leaders are sensitive to the behavioural tendency associated with the certainty effect. This observation leads to the question of how to detect those problems and, how to correct them so as to avoid non-negligible loss of money for construction projectsNon UBCUnreviewedFacultyOthe
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