321 research outputs found
A reassessment of the nomenclature of polychlorinated biphenyl (PCB) metabolites.
Polychlorinated biphenyls (PCBs) are a widespread class of persistent organic chemicals that accumulate in the environment and humans and are associated with a broad spectrum of health effects. PCB biotransformation has been shown to lead to two classes of PCB metabolites that are present as contaminant residues in the tissues of selected biota: hydroxylated (HO) and methyl sulfone (MeSO2) PCBs. Although these two types of metabolites are related structures, different rules for abbreviation of both classes have emerged. It is important that a standardized nomenclature for the notation of PCB metabolites be universally agreed upon. We suggest that the full chemical name of the PCB metabolite and a shorthand notation should be adopted using the International Union of Pure and Applied Chemistry's chemical name/original Ballschmiter and Zell number of the parent congener, followed by the assignment of the phenyl ring position number of the MeSO2- or HO-substituent. This nomenclature provides a clear, unequivocal set of rules in naming and abbreviating the PCB metabolite structure. Furthermore, this unified PCB metabolite nomenclature approach can be extended to the naming and abbreviation of potential metabolites of structurally analogous contaminants such as HO-polybrominated biphenyls and HO-polybrominated diphenyl ethers
Contemporary 14C radiocarbon levels of oxygenated polybrominated diphenyl ethers (O-PBDEs) isolated in sponge–cyanobacteria associations
Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Marine Pollution Bulletin 62 (2011): 631-636, doi:10.1016/j.marpolbul.2010.12.022.Considerable debate surrounds the sources of oxygenated polybrominated diphenyl
ethers (O-PBDEs) in wildlife as to whether they are naturally produced or result from
anthropogenic industrial activities. Natural radiocarbon (14C) abundance has proven to
be a powerful tool to address this problem as recently biosynthesized compounds contain contemporary (i.e. modern) amounts of atmospheric radiocarbon; whereas
industrial chemicals, mostly produced from fossil fuels, contain no detectable 14C.
However, few compounds isolated from organisms have been analyzed for their
radiocarbon content. To provide a baseline, we analyzed the 14C content of four OPBDEs.
These compounds, 6-OH-BDE47, 2’-OH-BDE68, 2’,6-diOH-BDE159, and a
recently identified compound, 2’-MeO-6-OH-BDE120, were isolated from the
tropical marine sponges Dysidea granulosa and Lendenfeldia dendyi. The modern
radiocarbon content of their chemical structures (i.e. diphenyl ethers, C12H22O)
indicates that they are naturally produced. This adds to a growing baseline on, at least,
the sources of these unusual compounds.The project described was supported in part by Grant Numbers NA16RU1496 and
NA06OAR4300227 from the National Oceanic and Atmospheric Administration, and
Grant Number 5P20RR021929 from the National Center for Research Resources
Supporting Information: Influence of Carbon and Lipid Sources on Variation of Mercury and Other Trace Elements in Polar Bears (\u3ci\u3eUrsus maritimus\u3c/i\u3e)
MATERIALS AND METHODS
Stable Carbon Isotope Analysis and Quality Control
Fatty Acids Analysis and Quality Control
Mercury and Other Trace Metal and Element Analysis and Quality Control
REFERENCE SECTIO
Pasts and pagan practices: moving beyond Stonehenge
Theorizing the past is not restricted to archaeology and interpretations of 'past' both influence and are themselves constituted within politicized understandings of self, community and in certain instances, spirituality. 'The past in the imagination of the present' is appropriated, variously, to give meaning to the present or to justify actions and interpret experiences. Summer solstice at Stonehenge, with an estimated 21,000 celebrants in 2005, is only the most publicized appropriation (by pagans and other adherents of alternative spirituality and partying) of a 'sacred site'; and conflicts and negotiations occurring throughout Britain are represented in popular and academic presentations of this 'icon of Britishness'. This paper presents work from the Sacred Sites, Contested Rites/Rights Project (http://www.sacredsites.org.uk) project, a collaboration of archaeology and anthropology informed by pagan and alternative approaches and standpoints investigating and theorizing discourse and practice of heritage management and pagan site users. Whether in negotiations around the Stonehenge solstice access or in dealing with numerous other sites, boundaries between groups or discourses are not clearly drawn - discursive communities merge and re-emerge. But clearly 'past' and 'site' are increasingly important within today's Britain, even as television archaeology increases its following, and pagan numbers continue to grow.</p
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