| 1. |
- Acharya, B. S., et al.
(författare)
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Introducing the CTA concept
- 2013
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Ingår i: Astroparticle physics. - : Elsevier BV. - 0927-6505 .- 1873-2852. ; 43, s. 3-18
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The Cherenkov Telescope Array (CTA) is a new observatory for very high-energy (VHE) gamma rays. CTA has ambitions science goals, for which it is necessary to achieve full-sky coverage, to improve the sensitivity by about an order of magnitude, to span about four decades of energy, from a few tens of GeV to above 100 TeV with enhanced angular and energy resolutions over existing VHE gamma-ray observatories. An international collaboration has formed with more than 1000 members from 27 countries in Europe, Asia, Africa and North and South America. In 2010 the CTA Consortium completed a Design Study and started a three-year Preparatory Phase which leads to production readiness of CTA in 2014. In this paper we introduce the science goals and the concept of CTA, and provide an overview of the project. (C) 2013 Elsevier B.V. All rights reserved.
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| 2. |
- Houde, Magali, et al.
(författare)
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POLYBROMINATED DIPHENYL ETHERS AND THEIR HYDROXYLATED ANALOGS IN PLASMA OF BOTTLENOSE DOLPHINS (TURSIOPS TRUNCATUS) FROM THE UNITED STATES EAST COAST.
- 2009
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Ingår i: Environmental Toxicology and Chemistry. - : Wiley. - 0730-7268 .- 1552-8618. ; 28:10, s. 2061-2068
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Tidskriftsartikel (refereegranskat)abstract
- Polybrominated diphenyl ethers (PBDEs) and hydroxylated-PBDEs (OH-PBDE) were determined in plasma of free-ranging bottlenose dolphins (Tursiops truncatus) from Charleston (CHS), South Carolina, and the Indian River Lagoon (IRL), Florida, US. Significantly lower sum (Sigma) of PBDE concentrations (sum of 12 congeners) were found in animals from the IRL [arithmetic mean: 5.454.63 ng/g wet weight (ww)] compared to CHS (3040 ng/g ww). BDE-47 was the predominant PBDE in dolphins from the IRL (50% of the SigmaPBDEs) and CHS (58%). SigmaPBDE concentrations in plasma of dolphins were negatively correlated with age at both locations. Fifteen and sixteen individual OH-PBDE congeners could be quantified in plasma of dolphins from IRL and CHS, respectively. Similar to SigmaPBDE, mean SigmaOH-PBDE concentrations were significantly higher in plasma of dolphins at CHS (1150708 pg/g ww) compared to IRL (624393 pg/g ww). The predominant congener at both locations was 6-OH-PBDE 47 (IRL: 384319 pg/g ww; CHS: 541344 pg/g ww) representing 61.5% of total SigmaOH-PBDE at IRL and 47.0% at CHS. Concentrations of SigmaOH-PBDEs were weakly negatively correlated with age in dolphins from both locations (P<0.05; IRL, R2=0.048; CHS, R2=0.021). In addition to the OH-PBDE congeners identified with technical standards, eight and four unidentified OH-PBDEs were detected and quantified respectively in animals from CHS (sum of unidentified OH-PBDEs=1.350.90 pg/g ww) and IRL (0.730.40 pg/g ww). Our results suggest that, unlike OH-PCBs, OH-PBDEs in bottlenose dolphins are minor products in plasma relative to SigmaPBDEs and a significant proportion may be a consequence of the dietary uptake of naturally produced methoxylated- and OH-PBDEs.
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| 3. |
- Ueno, Daisuke, et al.
(författare)
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Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) in the abiotic environment : surface water and precipitation from Ontario, Canada.
- 2008
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Ingår i: Environ Sci Technol. - 0013-936X. ; 42:5, s. 1657-64
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Tidskriftsartikel (refereegranskat)abstract
- Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have been identified as metabolites of PBDEs, and also as compounds of natural origin in the marine environment; however, there has only been very limited study of their presence in the abiotic environment. In the present study, OH-PBDEs were determined in samples of surface water and precipitation (rain and snow) collected from sites in Ontario, Canada. OH-PBDEs were detected in all the samples analyzed, although half of the observed peaks did not correspond to any of the 18 authentic standards available. Fluxes of sigmaOH-PBDEs ranged from 3.5 to 190 pg/m2 in snow and from 15 to 170 pg/m2/day in rain, and those were higher at three of the southern Ontario locations relative to a single northern remote site. Concentrations of sigmaOH-PBDEs ranged from 2.2 to 70 pg/L in water and from < 1 to 420 pg/g in particulate organic carbon (POC), and higher values were found near sewage treatment plant (STP) outfalls in Lake Ontario. Partition coefficients (log K(oc)) for OH-PBDEs ranged from 4.0 to 5.1. The results in this study suggest that OH-PBDEs are ubiquitous in the abiotic environment and most likely are produced through reaction of PBDEs with atmospheric OH radicals. As well, they may be present in surface waters near STPs due to oxidation of PBDEs and inflows from metabolism by humans and animals.
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