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471.
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M. Robbins Church Paul W. Shaffer Keith N. Eshleman Barry P. Rochelle 《Water, air, and soil pollution》1990,50(1-2):39-48
Using newly available regional data sets we examine the potential for future changes in stream acid neutralizing capacity (ANC) for the Southern Blue Ridge Province (SBRP) of the U.S. as related to (1) levels of S deposition, (2) retention of S within watersheds, (3) current surface water SO4, and (4) potential historical changes in surface water chemistry. We conclude that, although (1) little change in surface water chemistry (as affected by acidic deposition) likely has occurred in the region to date, and (2) soils are currently retaining a majority of atmospherically deposited S, it is likely that marked increases in surface water SO4 will occur. Such increases could be accompanied by significant surface water acidification (loss of ANC). 相似文献
473.
Hucker B Wakeling L Vriesekoop F 《Journal of agricultural and food chemistry》2011,59(23):12278-12285
This research aimed to develop a simple and effective method for analyzing thiamin (B(1)), riboflavin (B(2)) and their respective vitamers by high performance liquid chromatography (HPLC) in fermented alcoholic beverages. The method developed here employs a phosphate buffer/methanol gradient elution on a single reverse phase column, coupled with independent fluorescent detection regimes. It also employs a precolumn derivatization to convert thiamin to thiochrome via an alkaline potassium ferricyanide solution. The method described here allowed a spike recovery of better than 97%, with a typical linear detection range (R(2) ≥ 0.9997) between ≤ 5 and ≥ 500 μg/L for all vitamers studied. Lager style beers were found to contain significantly (p < 0.001) less thiamin than other tested styles of beers (lager, 35.7 μg/L; ale, 88.3 μg/L; stout/porters, 104.4 μg/L; wheat beers, 130.7 μg/L), which may be due to the raw material and extensive processing that occurs for this style. There was no statistical difference (p = 0.608) between the riboflavin content of each beer style. Furthermore, wines and ciders contain less thiamin and riboflavin than beer, which is also likely to be due to the base materials used and the differences in processing steps to produce these beverages. 相似文献
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Boston SE Barry M O'Sullivan ML 《The Canadian veterinary journal. La revue veterinaire canadienne》2011,52(6):650-655
A 7-year-old, spayed, female great Pyrenees with a primary tumor of the distal radius was treated with placement of a bone plate that spanned the tumor. The goals were palliation and prevention of pathologic fracture. This is an option for select patients with osteosarcoma. 相似文献
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Rufus Isaacs Jim Hardie Alastair J. Hick Barry J. Pye Lesley E. Smart Lester J. Wadhams Christine M. Woodcock 《Pest management science》1993,39(4):349-355
Isothiocyanates have been shown to stimulate olfactory receptors on the antennae of the black bean aphid, Aphis fabae Scop. Single-cell recording techniques show that this aphid has receptors at the proximal primary rhinarium which are sensitive to n-butyl isothiocyanate. In laboratory assays, 4-pentenyl and n-butyl isothiocyanates were repellent at similar threshold concentrations. A. fabae was attracted to host-plant odour, but addition of either isothiocyanate to the airstream masked this attraction. Field trials on spring beans did not produce any consistent reduction in numbers of alate or apterous aphids on the crop, and yields were not improved by either compound. 相似文献
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Shrub recruitment in arid and semiarid regions often occurs in pulses controlled by specific weather events. Previous research suggested that Wyoming sagebrush in Wyoming is no exception. We examined four species/subspecies of sagebrush in Nevada, in 2009 and 2010, to discover if evidence of recruitment pulses was contained in the annual growth-ring records. Sagebrush species and subspecies occur on a wide variety of ecological sites that require different management strategies. Species included black sagebrush (Artemisia nova A. Nelson), Wyoming big sagebrush (Artemisia tridentata subsp. wyomingensis Beetle & Young), Lahontan sagebrush (Artemisia arbuscula subsp. longicaulis Winward & McArthur), and low sagebrush (Artemisia arbuscula Nutt. ssp. arbuscula). Eighty stem sections were collected from each of 24 stands (6 stands per species or subspecies) at different geographic locations along east-west or north-south gradients where each species or subspecies naturally occurred. Annual growth-ring analysis was used to determine the year of establishment and the relationship between recruitment and weather events. Results indicated stand ages and locations were different (P > 0.001) among species and subspecies, and years of recruitment were strongly correlated with local and hemispheric weather patterns. Linear and multiple regressions modeled recruitment pulses for all four species. Weather-based predictor variables indicated complex interactions between recruitment and climatic controls. Pacific Decadal Oscillation (PDO) index variables were prominent predictors for all four species at their associated sites. Other important local weather variables included total annual precipitation the year before recruitment, the year of recruitment, and the year following recruitment. In Nevada and the Great Basin, it is imperative that successful sagebrush seeding technologies are discovered and implemented. Ecological restoration and postfire rehabilitation methods should be timed correctly with respect to precipitation patterns (positive phase PDO) and/or designed to mimic conditions responsible for natural sagebrush recruitment. 相似文献
480.