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Aquamarine beryl from Zealand Station, Canada: a mineralogical and stable isotope study

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Aquamarine crystals occur in crustal A-type pegmatite-aplite dykes and associated quartz veins and greisen zones at the Zealand Station Be-Mo deposit, south-central New Brunswick (Canada). Electron-probe microanalysis (EPMA) of aquamarine determined that the chromophore Fe (800 C) of 1.3-1.4 wt. % in beryl channels. The δ^sup 18^O of the quartz and beryl were within 1 [per thousand], consistent with magmatic crystallization from an ^sup 18^O enriched source, and δD values on channel water have magmatic signatures. [PUBLICATION ABSTRACT]
Arc-continent collision and the formation of continental crust: a new geochemical and isotopic record from the Ordovician Tyrone Igneous Complex, Ireland

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Collisions between oceanic island-arc terranes and passive continental margins are thought to have been important in the formation of continental crust throughout much of Earth's history. Magmatic evolution during this stage of the plate-tectonic cycle is evident in several areas of the Ordovician Grampian-Taconic orogen, as we demonstrate in the first detailed geochemical study of the Tyrone Igneous Complex, Ireland. New U-Pb zircon dating yields ages of 493 2 Ma from a primitive mafic intrusion, indicating intra-oceanic subduction in Tremadoc time, and 475 10 Ma from a light rare earth element (LREE)-enriched tonalite intrusion that incorporated Laurentian continental material by early Arenig time (Early Ordovician, Stage 2) during arc-continent collision. Notably, LREE enrichment in volcanism and silicic intrusions of the Tyrone Igneous Complex exceeds that of average Dalradian (Laurentian) continental material that would have been thrust under the colliding forearc and potentially recycled into arc magmatism. This implies that crystal fractionation, in addition to magmatic mixing and assimilation, was important to the formation of new crust in the Grampian-Taconic orogeny. Because similar super-enrichment of orogenic melts occurred elsewhere in the Caledonides in the British Isles and Newfoundland, the addition of new, highly enriched melt to this accreted arc terrane was apparently widespread spatially and temporally. Such super-enrichment of magmatism, especially if accompanied by loss of corresponding lower crustal residues, supports the theory that arc-continent collision plays an important role in altering bulk crustal composition toward typical values for ancient continental crust. [PUBLICATION ABSTRACT]
Arctic Oil Drilling Plans Raise Environmental Health Concerns

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A global leader in serving libraries of all types, ProQuest LLC (“ProQuest”) supports the breadth of the information community with innovative discovery solutions that power the business of books and the best in research experience. More than a content provider or aggregator, ProQuest is an information partner, creating indispensable research solutions that connect people and information. Through innovative, user-centered discovery technology, ProQuest offers billions of pages of global content that includes historical newspapers, dissertations, and uniquely relevant resources for researchers of any age and sophistication—including content not likely to be digitized by others.
ARE COMPOST EMISSIONS A STRONG OZONE SOURCE?

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Four simple compounds that do not contribute much toward ground-level ozone formation comprise more than 75% of compost pile Volatile Organic Compound (VOC) emissions, according to preliminary results of research conducted by the University of California, Davis. The study, made possible with support from the California Department of Resources Recycling and Recovery and the Alameda County Waste Management Authority, indicates that commercial composting operations do not contribute as much to regional ozone problems as previously thought. It suggests that regulations attempting to limit the amount of VOCs emitted from green waste composting facilities are likely to be more effective at reaching clean air goals if targeted at the most reactive compounds. The Clean Air Act does not differentiate between VOCs. But the USEPA, in a 2005 guidance document to states and air districts, encouraged air agencies to take advantage of the new science of reactivity when updating their clean air plans, revising their VOC inventories, and when considering regulations.
Are Current or Future Mesothelioma Epidemics in Hong Kong the Tragic Legacy of Uncontrolled Use of Asbestos in the Past?

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BACKGROUND: Because of the long latent period of asbestos-related mesothelioma, investigators suggest that the high incidence of this disease will continue in the coming decades. OBJECTIVES: We describe the time trends of mesothelioma incidence and its relationship to historical consumption of asbestos in Hong Kong and project future trends of mesothelioma incidence. METHODS: We obtained local annual consumption of total asbestos for 1960-2006 (converted to kilograms per person per year). Age-standardized incidence rates (ASIRs) of mesothelioma were computed and depicted on graphs using the centered moving average method. Indirectly standardized rates were regressed on a transformation of consumption data that assumed that the latency between asbestos exposure and mesothelioma diagnosis followed a normal distribution with a mean +/- SD of 42 +/- 10.5 years. RESULTS: ASIRs for males started to increase substantially in 1994 and were highest in 2004; for females, ASIRs climbed in the 1980s and in the early 1990s but have fluctuated without obvious trends in recent years. The highest asbestos consumption level in Hong Kong was in 1960-1963 and then decreased sharply afterward. Using past asbestos consumption patterns, we predict that the mesothelioma incidence rate for males will peak in 2009, with the number of cases peaking in 2014, and then slowly decline in the coming decades. CONCLUSIONS: Hong Kong experienced an epidemic of mesothelioma from 2000 to 2006 that corresponded with the peak of local asbestos consumption in the early 1960s assuming an average latent period of 42 years. The incidence is anticipated to decline in the coming decades but may not decrease back to the background risk level (the risk unrelated to asbestos exposure).
Are Particulate Matter Exposures Associated with Risk of Type 2 Diabetes?

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A global leader in serving libraries of all types, ProQuest LLC (“ProQuest”) supports the breadth of the information community with innovative discovery solutions that power the business of books and the best in research experience. More than a content provider or aggregator, ProQuest is an information partner, creating indispensable research solutions that connect people and information. Through innovative, user-centered discovery technology, ProQuest offers billions of pages of global content that includes historical newspapers, dissertations, and uniquely relevant resources for researchers of any age and sophistication—including content not likely to be digitized by others.
Are We on the Same Page?

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A global leader in serving libraries of all types, ProQuest LLC (“ProQuest”) supports the breadth of the information community with innovative discovery solutions that power the business of books and the best in research experience. More than a content provider or aggregator, ProQuest is an information partner, creating indispensable research solutions that connect people and information. Through innovative, user-centered discovery technology, ProQuest offers billions of pages of global content that includes historical newspapers, dissertations, and uniquely relevant resources for researchers of any age and sophistication—including content not likely to be digitized by others.
Are We Ready?

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Even before the downturn in the economy and the subsequent hard times for the forest industry, finding qualified people to put in the seats of our logging equipment and to work in our production facilities was tough. In Alberta and B.C., the forest industry was often a second choice for potential employees who could choose much higher paying jobs in oil and gas. It was much the same in Ontario, but it is mining that scooped up the people as the gold mines around Timmins and the nickel mines in Sudbury could afford to pay substantially more than the forest industry. That was when U.S. housing starts were over 2 million annually and Canada's forest industry was going flat out to keep up with the demand for dimensional lumber from our southern neighbours. We couldn't compete then in terms of compensation with the other resource sector industries for employees, so how are we going to do it now? Around 2005, 1 recall conducting site visits for articles for this magazine with logging contractors in Alberta They told me they would place ads for well-paying forestry jobs but wouldn't get one response. In the boardrooms of major forest products producers, executives pondered how to attract people to mill jobs, and post-secondary institutions struggled with declining numbers for enrolment in forestry and wood products processing programs.
Are We Really Addressing the Core of Children's Environmental Health?

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A global leader in serving libraries of all types, ProQuest LLC (“ProQuest”) supports the breadth of the information community with innovative discovery solutions that power the business of books and the best in research experience. More than a content provider or aggregator, ProQuest is an information partner, creating indispensable research solutions that connect people and information. Through innovative, user-centered discovery technology, ProQuest offers billions of pages of global content that includes historical newspapers, dissertations, and uniquely relevant resources for researchers of any age and sophistication—including content not likely to be digitized by others.
Are We There Yet First

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A global leader in serving libraries of all types, ProQuest LLC (“ProQuest”) supports the breadth of the information community with innovative discovery solutions that power the business of books and the best in research experience. More than a content provider or aggregator, ProQuest is an information partner, creating indispensable research solutions that connect people and information. Through innovative, user-centered discovery technology, ProQuest offers billions of pages of global content that includes historical newspapers, dissertations, and uniquely relevant resources for researchers of any age and sophistication—including content not likely to be digitized by others.
Are you getting the right blend of biodiesel fuel?

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With greenhouse gases (and gas prices) rising, some consumers have turned to an alternative: biodiesel, a fuel prepared from animal fats and vegetable oils.
Arsenic and Bladder Cancer: Observations and Suggestions

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Arsenic from drinking water is a well-known risk factor for bladder cancer. The purpose of this paper is to systematize some important yet often overlooked facts considering the relationship between arsenic exposure and the occurrence of bladder cancer. Since the exposure to inorganic arsenic from food, inhaled air, and skin absorption as well as arsenic methylation ability are not fully investigated, our assumption is that the exposure of arsenic only from drinking water is underestimated and its role as a risk factor is highly overestimated. This paper proposes some qualitative and quantitative parameters of arsenic as a risk factor for bladder cancer. The recommended qualitative parameters of arsenic intake are first, pathways of exposure, and second, toxicity and metabolism. The suggested quantitative parameters of arsenic intake include amounts of arsenic absorbed in the body, duration of arsenic exposure, and duration of arsenic presence in the urinary bladder. This approach can be implemented in a systematic classification and explanation of various risk factors and their mutual inter actions for other types of cancer or diseases in general. [PUBLICATION ABSTRACT]
Arsenic and Infectious Disease

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A global leader in serving libraries of all types, ProQuest LLC (“ProQuest”) supports the breadth of the information community with innovative discovery solutions that power the business of books and the best in research experience. More than a content provider or aggregator, ProQuest is an information partner, creating indispensable research solutions that connect people and information. Through innovative, user-centered discovery technology, ProQuest offers billions of pages of global content that includes historical newspapers, dissertations, and uniquely relevant resources for researchers of any age and sophistication—including content not likely to be digitized by others.
Arsenic as an Endocrine Disruptor: Arsenic Disrupts Retinoic Acid Receptor-and Thyroid Hormone Receptor-Mediated Gene Regulation and Thyroid Hormone-Mediated Amphibian Tail Metamorphosis

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BACKGROUND: Chronic exposure to excess arsenic in drinking water has been strongly associated with increased risks of multiple cancers, diabetes, heart disease, and reproductive and developmental problems in humans. We previously demonstrated that As, a potent endocrine disruptor at low, environmentally relevant levels, alters steroid signaling at the level of receptor-mediated gene regulation for all five steroid receptors. OBJECTIVES: The goal of this study was to determine whether As can also disrupt gene regulation via the retinoic acid (RA) receptor (RAR) and/or the thyroid hormone (TH) receptor (TR) and whether these effects are similar to previously observed effects on steroid regulation. METHODS AND RESULTS: Human embryonic NT2 or rat pituitary GH3 cells were treated with 0.01-5 microM sodium arsenite for 24 hr, with or without RA or TH, respectively, to examine effects of As on receptor-mediated gene transcription. At low, noncytotoxic doses, As significantly altered RAR-dependent gene transcription of a transfected RAR response element-luciferase construct and the native RA-inducible cytochrome P450 CYP26A gene in NT2 cells. Likewise, low-dose As significantly altered expression of a transfected TR response element-luciferase construct and the endogenous TR-regulated type I deiodinase (DIO1) gene in a similar manner in GH3 cells. An amphibian ex vivo tail metamorphosis assay was used to examine whether endocrine disruption by low-dose As could have specific pathophysiologic consequences, because tail metamorphosis is tightly controlled by TH through TR. TH-dependent tail shrinkage was inhibited in a dose-dependent manner by 0.1- 4.0 microM As. CONCLUSIONS: As had similar effects on RAR- and TR-mediated gene regulation as those previously observed for the steroid receptors, suggesting a common mechanism or action. Arsenic also profoundly affected a TR-dependent developmental process in a model animal system at very low concentrations. Because RAR and TH are
Arsenic Exposure and Childhood Cancer - A Systematic Review of the Literature

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The literature on environmental arsenic exposure and childhood cancer risk comprises 1) studies seeking childhood cancers among arsenic-exposed populations, 2) studies seeking arsenic exposure among childhood cancer cases, and 3) studies seeking associations in populations with both arsenic exposures and childhood cancer cases. No skin cancers were found in dermal examinations of over 25,000 children in Southwest Taiwan or West Bengal, India, with high drinking-water arsenic levels. Childhood cancer types were not different for those living near a Swedish smelter. In Montreal, Canada, children with acute lymphoblastic leukemia did not have drinking-water arsenic more frequently either prenatal or postnatal, and British children with cancer did not have early exposure to environmental sources of airborne arsenic. Neither hair arsenic levels in Woburn, Massachusetts, nor water arsenic levels in Fallon, Nevada, were elevated for children with leukemia. The literature, while limited, does not seem to support an association between arsenic exposure and childhood cancers. [PUBLICATION ABSTRACT]