2,715 research outputs found

    Spoiled Brands: Protecting Your Company\u27s Goodwill and Assets from Food Contamination Claims

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    For most people, going to a restaurant ends with a sense of satisfaction and enjoyment, not sickness and the possibility of death. This is also true when purchasing products at a local grocery store. However, recent events have cast doubt on the safety of Americaā€™s food supply. The issue facing risk managers is how to reduce these escalating risks and manage any unfortunate outcomes. The cost of food contamination can be devastating to a business financially, and can result in both direct losses related to product recall expenses and indirect losses such as lost reputation and goodwill. By reducing the frequency and severity of such risks and using proper risk transfer techniques, risk managers can help prevent catastrophic losses from contaminated food, and ensure the long-term viability of their company\u27s brands

    For geological investigations with airborne thermal infrared multispectral images: Transfer of calibration from laboratory spectrometer to TIMS as alternative for removing atmospheric effects

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    This paper describes an empirical method to correct TIMS (Thermal Infrared Multispectral Scanner) data for atmospheric effects by transferring calibration from a laboratory thermal emission spectrometer to the TIMS multispectral image. The method does so by comparing the laboratory spectra of samples gathered in the field with TIMS 6-point spectra for pixels at the location of field sampling sites. The transference of calibration also makes it possible to use spectra from the laboratory as endmembers in unmixing studies of TIMS data

    Casingless down-hole for sealing an ablation volume and obtaining a sample for analysis

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    A casing-less down hole sampling system for acquiring a subsurface sample for analysis using an inductively coupled plasma system is disclosed. The system includes a probe which is pushed into the formation to be analyzed using a hydraulic ram system. The probe includes a detachable tip member which has a soil point mad a barb, with the soil point aiding the penetration of the earth, and the barb causing the tip member to disengage from the probe and remain in the formation when the probe is pulled up. The probe is forced into the formation to be tested, and then pulled up slightly, to disengage the tip member and expose a column of the subsurface formation to be tested. An instrumentation tube mounted in the probe is then extended outward from the probe to longitudinally extend into the exposed column. A balloon seal mounted on the end of the instrumentation tube allows the bottom of the column to be sealed. A source of laser radiation is emitted from the instrumentation tube to ablate a sample from the exposed column. The instrumentation tube can be rotated in the probe to sweep the laser source across the surface of the exposed column. An aerosol transport system carries the ablated sample from the probe to the surface for testing in an inductively coupled plasma system. By testing at various levels in the down-hole as the probe is extracted from the soil, a profile of the subsurface formation may be obtained

    Copper complexation during spring phytoplankton blooms in coastal waters

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    Cupric ion bioassays were conducted throughout the spring phytoplankton bloom season at two stations-one estuarine, dominated by dinoflagellates, the other coastal, dominated by diatoms. Copper-complexing ligands were detected at both locations throughout this period. Ligand concentrations varied between 0.1 and 0.75 Ī¼M, with the estuarine concentrations typically 2ā€“4 times higher than coastal values. Ligands from both locations were destroyed by UV-oxidation and had similar conditional stability constants (range 108.3 to 109.2) that were significantly correlated with pH, suggesting that the complexing materials are organic chelators with weak acid functional groups. All measured or calculated parameters (DOC, ligand concentration, total copper concentration, salinity, and pH) remained relatively constant at the coastal station through time. The estuarine station was more dynamic, with DOC, total copper, and ligand concentrations varying 2ā€“4 fold during the study. Although ligand concentrations were significantly different between the two locations, concomitant fluctuations in total dissolved copper and conditional stability constants resulted in a relatively constant estimate of the maximum free cupric ion activity at both stations (near 10ā€“11 M). This suggests that copper toxicity alone was not responsible for the distinctly different estuarine and nearshore phytoplankton assemblages, although sensitive species might have been inhibited at both locations. Major phytoplankton blooms at both sites were not accompanied by changes in DOC or complexation capacity. A significant inverse correlation between ligand concentration and salinity suggests a terrestrial or sedimentary origin for the copper-complexing compounds

    Mthfs is an Essential Gene in Mice and a Component of the Purinosome

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    Tetrahydrofolates (THF) are a family of cofactors that function as one-carbon donors in folate-dependent one-carbon metabolism, a metabolic network required for the de novo synthesis of purines, thymidylate, and for the remethylation of homocysteine to methionine in the cytoplasm. 5-FormylTHF is not a cofactor in one-carbon metabolism, but serves as a storage form of THF cofactors. 5-formylTHF is mobilized back into the THF cofactor pool by methenyltetrahydrofolate synthetase (MTHFS), which catalyzes the irreversible and ATP-dependent conversion 5-formyltetrahydrofolate to 5,10-methenyltetrahydrofolate. Mthfs is not an essential gene in Arabidopsis, but MTHFS expression is elevated in animal tumors, enhances de novo purine synthesis, confers partial resistance to antifolate purine synthesis inhibitors and increases rates of folate catabolism in mammalian cell cultures. However, the mechanisms underlying these effects of MTHFS expression have yet to be established. The purpose of this study was to investigate the role and essentiality of MTHFS in mice. Mthfs was disrupted through the insertion of a gene trap vector between exons 1 and 2. Mthfsgt/+ mice were fertile and viable. No Mthfsgt/gt embryos were recovered from Mthfsgt/+ intercrosses, indicating Mthfs is an essential gene in mice. Tissue MTHFS protein levels are decreased in both Mthfsgt/+ and Mthfs+/+ mice placed on a folate and choline deficient diet, and mouse embryonic fibroblasts from Mthfsgt/+ embryos exhibit decreased capacity for de novo purine synthesis without impairment in de novo thymidylate synthesis. MTHFS was shown to co-localize with two enzymes of the de novo purine synthesis pathway in HeLa cells in a cell cycle-dependent manner, and to be modified by the small ubiquitin-like modifier (SUMO) protein. Mutation of the consensus SUMO modification sites on MTHFS eliminated co-localization of MTHFS with the de novo purine biosynthesis pathway under purine-deficient conditions. The results from this study indicate that MTHFS enhances purine biosynthesis by delivering 10-formylTHF to the purinosome in a SUMO-dependent fashion

    Short versus long silver nanowires: a comparison of in vivo pulmonary effects post instillation.

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    BackgroundSilver nanowires (Ag NWs) are increasingly being used to produce touchscreens for smart phones and computers. When applied in a thin film over a plastic substrate, Ag NWs create a transparent, highly-conductive network of fibers enabling the touch interface between consumers and their electronics. Large-scale application methods utilize techniques whereby Ag NW suspensions are deposited onto substrates via droplets. Aerosolized droplets increase risk of occupational Ag NW exposure. Currently, there are few published studies on Ag NW exposure-related health effects. Concerns have risen about the potential for greater toxicity from exposure to high-aspect ratio nanomaterials compared to their non-fibrous counterparts. This study examines whether Ag NWs of varying lengths affect biological responses and silver distribution within the lungs at different time-points.MethodsTwo different sizes of Ag NWs (2 Ī¼m [S-Ag NWs] and 20 Ī¼m [L-Ag NWs]) were tested. Male, Sprague-Dawley rats were intratracheally instilled with Ag NWs (0, 0.1, 0.5, or 1.0 mg/kg). Broncho-alveolar lavage fluid (BALF) and lung tissues were obtained at 1, 7, and 21 days post exposure for analysis of BAL total cells, cell differentials, and total protein as well as tissue pathology and silver distribution.Results and conclusionsThe two highest doses produced significant increases in BAL endpoints. At Day 1, Ag NWs increased total cells, inflammatory polymorphonuclear cells (PMNs), and total protein. PMNs persisted for both Ag NW types at Day 7, though not significantly so, and by Day 21, PMNs appeared in line with sham control values. Striking histopathological features associated with Ag NWs included 1) a strong influx of eosinophils at Days 1 and 7; and 2) formation of Langhans and foreign body giant cells at Days 7 and 21. Epithelial sloughing in the terminal bronchioles (TB) and cellular exudate in alveolar regions were also common. By Day 21, Ag NWs were primarily enclosed in granulomas or surrounded by numerous macrophages in the TB-alveolar duct junction. These findings suggest short and long Ag NWs produce pulmonary toxicity; thus, further research into exposure-related health effects and possible exposure scenarios are necessary to ensure human safety as Ag NW demand increases

    Exploratory Chandra Observations of the Three Highest Redshift Quasars Known

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    We report on exploratory Chandra observations of the three highest redshift quasars known (z = 5.82, 5.99, and 6.28), all found in the Sloan Digital Sky Survey. These data, combined with a previous XMM-Newton observation of a z = 5.74 quasar, form a complete set of color-selected, z > 5.7 quasars. X-ray emission is detected from all of the quasars at levels that indicate that the X-ray to optical flux ratios of z ~ 6 optically selected quasars are similar to those of lower redshift quasars. The observations demonstrate that it will be feasible to obtain quality X-ray spectra of z ~ 6 quasars with current and future X-ray missions.Comment: 15 pages, ApJL, in press; small revisions to address referee Comment

    Antioxidant responses and lipid peroxidation in gills and erythrocytes of fish (Rhabdosarga sarba) upon exposure to Chattonella marina and hydrogen peroxide : implications on the cause of fish kills

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    Author Posting. Ā© Elsevier B.V., 2006. 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 Journal of Experimental Marine Biology and Ecology 336 (2006): 230-241, doi:10.1016/j.jembe.2006.05.013.Chattonella marina, a red tide or harmful algal bloom species, has caused mass fish kills and serious economic loss worldwide, and yet its toxic actions remain highly controversial. Previous studies have shown that this species is able to produce reactive oxygen species (ROS), and therefore postulated that ROS are the causative agents of fish kills. The present study investigates antioxidant responses and lipid peroxidation in gills and erythrocytes of fish (Rhabdosarga sarba) upon exposure to C. marina, compared with responses exposed to equivalent and higher levels of ROS exposure. Even though C. marina can produce a high level of ROS, gills and erythrocytes of sea bream exposed to C. marina for 1 to 6 h showed neither significant induction of antioxidant enzymes nor lipid peroxidation. Antioxidant responses and oxidative damage did not occur as fish mortality began to occur, yet could be induced upon exposure to artificially supplied ROS levels an order of magnitude higher. The result of this study implies that ROS produced by C. marina is not the principal cause of fish kills.This study was supported by a CERG grant (CityU 1109/03M / No. 9040864) of the University Grants Committee, Hong Kong SAR government. Support for Don Anderson was also provided by the U.S. National Science Foundation through grant no. OCE-0136861
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