124 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

    ‘Citicoline’ and support of the memory function: Evaluation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006

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    Following an application from Egde Pharma Sp. z o.o, submitted for authorisation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of Poland, 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 citicoline and memory. The Panel considers that the food, citicoline (cytidine 5-diphosphocholine, CDP-Choline) inner salt, is sufficiently characterised. Improvement, maintenance or reduced loss of memory is a beneficial physiological effect for middle-aged or elderly adults encountering age-associated subjective memory impairment. The applicant identified three pertinent human intervention studies in healthy individuals that investigated the effect of citicoline on memory. In weighing the evidence, the Panel took into account that only one randomised controlled trial in healthy participants showed a beneficial effect of citicoline on episodic memory when consumed at doses of 500 mg/day for 12 weeks, whereas this effect has not been observed in another study using citicoline at doses of 1 g/day for 3 months or supported by data obtained in patients with dementia using doses of 1 g/day for 12 weeks and 12 months. No convincing evidence of a plausible mechanism by which citicoline or any of its components (in addition to their endogenous synthesis) could exert an effect on memory in humans has been provided. The Panel concludes that a cause-and-effect relationship has not been established between the consumption of citicoline (CDP-Choline) inner salt and improvement, maintenance or reduced loss of memory in middle-aged or elderly adults encountering age-associated subjective memory impairment

    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

    Joselito® and lowering of LDL-cholesterol concentration, blood pressure, and reduction of coronary heart disease risk: Evaluation of a health claim pursuant to Article 14 of Regulation (EC) No 1924/2006

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    Following an application from C & aacute;rnicas Joselito S.A. pursuant to Article 14 of Regulation (EC) No 1924/2006 via the Competent Authority of Spain, 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 'Joselito ham increases antioxidant substances in the body, reduces blood pressure and plasma triglycerides, decreases oxidative stress and prevents effect in diseases related to the cardiovascular and intestinal systems'. The scope of the application was proposed to fall under a health claim referring to disease risk reduction. The food constituent that is the subject of the health claim is Joselito, an Iberian ham characterised by a high content of oleic acid. The Panel considers that the food is sufficiently characterised. The Panel considers that lowering of LDL-cholesterol concentration and blood pressure is a beneficial effect by decreasing the risk of coronary heart disease. Upon a request from EFSA, the applicant identified one human intervention study as being pertinent to the claim. However, due to methodological limitations, the Panel considers that no conclusions can be drawn from this study for the scientific substantiation of the claim. The Panel notes that no human intervention studies from which conclusions could be drawn for the scientific substantiation of the claim were provided by the applicant. The Panel concludes that a cause and effect relationship has not been established between the intake of Joselito (R) ham and the reduction of LDL-cholesterol concentration or blood pressure

    Scientific Opinion on additional scientific data related to the safety of preparations of Rheum palmatum L., Rheum officinale Baill. and their hybrids, Rhamnus purshiana DC., Rhamnus frangula L. and Cassia senna L., submitted pursuant to Article 8(4) of Regulation (EC) No 1925/2006

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    The Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver a scientific opinion on the safety of plant preparations from the root or rhizome of Rheum palmatum L., Rheum officinale Baill. and their hybrids, from the bark of Rhamnus frangula L. and Rhamnus purshiana DC. and from the leaf or fruit of Cassia senna L., which have been placed under Union scrutiny in Part C of Annex III in accordance with Article 8(4) of Regulation (EC) No 1925/2006. The NDA Panel reviewed the additional scientific data submitted during the period of scrutiny and the public consultation by interested parties. The pertinent scientific data were in vitro and in vivo genotoxicity studies on the plant preparations under consideration. All the results of the genotoxicity studies on plant preparations were negative. However, the plant preparations that were tested in the submitted studies were not sufficiently characterised with respect to the content of total and individual hydroxyanthracene derivatives (HADs) and components other than HADs. The studies confirmed the presence of ■■■■■, known to be genotoxic in vivo, and ■■■■■, shown to be genotoxic in vitro. In line with the EFSA Scientific Committee statement on genotoxicity assessment of chemical mixtures, considering the presence of an in vivo genotoxic compound, the plant preparations used in these studies have to be considered of concern for genotoxicity. Thus, the safety of preparations containing HADs from the root or rhizome of Rheum palmatum L., Rheum officinale Baill. and their hybrids, from the leaf or fruit of Cassia senna L. and from the bark of Rhamnus frangula L. and Rhamnus purshiana DC. cannot be established based on the submitted studies

    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
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