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101.
Two groups of 4 Hereford steers were housed in a controlled environment room and exposed to simulated high summer temperatures. Both groups were fed a barley grain and hay diet ad libitum. The barley in one diet contained 0.5% w/w ergots of Claviceps purpurea. Within one week of feeding the ergot diet mean rectal temperature was significantly elevated (P less than 0.05) each afternoon (up to 41 degrees C) but returned to normal overnight. Elevated rectal temperature was accompanied by other signs of heat stress, reduced feed intake, body weight loss and depression or serum prolactin concentration. Symptoms disappeared within 1 week of ceasing to feed the ergot diet. 相似文献
102.
103.
Weinstein NM Blais MC Harris K Oakley DA Aronson LR Giger U 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2007,21(2):287-292
BACKGROUND: Naturally occurring alloantibodies produced against A and B red cell antigens in cats can cause acute hemolytic transfusion reactions. Blood incompatibilities, unrelated to the AB blood group system, have also been suspected after blood transfusions through routine crossmatch testing or as a result of hemolytic transfusion reactions. HYPOTHESIS: Incompatible crossmatch results among AB compatible cats signify the presence of a naturally occurring alloantibody against a newly identified blood antigen in a group of previously never transfused blood donor cats. The associated alloantibody is clinically important based upon a hemolytic transfusion reaction after inadvertent transfusion of red cells expressing this red cell antigen in a feline renal transplant recipient that lacks this red cell antigen. METHODS: Blood donor and nonblood donor cats were evaluated for the presence of auto- and alloantibodies using direct antiglobulin and crossmatch tests, respectively, and were blood typed for AB blood group status. Both standard tube and novel gel column techniques were used. RESULTS: Plasma from 3 of 65 cats and 1 feline renal transplant recipient caused incompatible crossmatch test results with AB compatible erythrocytes indicating these cats formed an alloantibody against a red cell antigen they lack, termed Mik. The 3 donors and the renal transplant recipient were crossmatch-compatible with one another. Tube and gel column crossmatch test results were similar. CONCLUSIONS AND CLINICAL IMPORTANCE: The absence of this novel Mik red cell antigen can be associated with naturally occurring anti-Mik alloantibodies and can elicit an acute hemolytic transfusion reaction after an AB-matched blood transfusion. 相似文献
104.
Ziolo RF Giannelis EP Weinstein BA O'horo MP Ganguly BN Mehrotra V Russell MW Huffman DR 《Science (New York, N.Y.)》1992,257(5067):219-223
A new magnetic material with appreciable optical transmission in the visible region at room temperature has been isolated as a gamma-Fe(2)O(3)/polymer nanocomposite. The synthesis is carried out in an ion-exchange resin at 60 degrees C. Magnetization and susceptibility data demonstrate loading-dependent saturation moments as high as 46 electromagnetic units per gram and superparamagnetism for lower loadings where particle sizes are less than 100 angstroms. Optical absorption studies show that the small-particle form of gamma-Fe(2)O(3) is considerably more transparent to visible light than the single-crystal form. The difference in absorption ranges from nearly an order of magnitude in the "red" spectral region to a factor of 3 at 5400 angstroms. The magnetization of the nanocomposite is greater by more than an order of magnitude than those of the strongest room-temperature transparent magnets, FeBO(3) and FeF(3). 相似文献
105.
Zhong TP Rosenberg M Mohideen MA Weinstein B Fishman MC 《Science (New York, N.Y.)》2000,287(5459):1820-1824
The first artery and vein of the vertebrate embryo assemble in the trunk by migration and coalescence of angioblasts to form endothelial tubes. The gridlock (grl) mutation in zebrafish selectively perturbs assembly of the artery (the aorta). Here it is shown that grl encodes a basic helix-loop-helix (bHLH) protein belonging to the Hairy/Enhancer of the split family of bHLH proteins. The grl gene is expressed in lateral plate mesoderm before vessel formation, and thereafter in the aorta and not in the vein. These results suggest that the arterial endothelial identity is established even before the onset of blood flow and implicate the grl gene in assignment of vessel-specific cell fate. 相似文献
106.
5 beta-Dihydrocortisol potentiated the threshold level (the smallest dose producing a measurable effect) of topically applied cortisol (0.02 percent) and dexamethasone (0.003 percent) in causing nuclear translocation of the cytosolic glucocorticoid receptor in rabbit iris-ciliary body tissue. 5 beta-Dihydrocortisol accumulates in cells cultured from trabecular meshwork specimens from patients with primary open-angle glaucoma, but not in similar cells derived from nonglaucomatous patients. In view of the sensitivity of patients with primary open-angle glaucoma to the effects of glucocorticoids in raising intraocular pressure, this potentiation may be responsible for the steroid sensitivity and for the ocular hypertension seen in this disorder. 相似文献
107.
Direct evidence for the adaptor hypothesis has been obtained by examining the codon recognition of a purified Escherichia coli valine transfer ribonucleic acid which was enzymatically mischarged with phenylalanine labeled with carbn-14 by reaction with purified phenylalanyl-transfer ribonucleic acid synthetase from Neurospora crassa. The mischarged transfer ribonucleic acid recognized the valine codons but failed to recognize the phenylalanine codon when tested in trinucleotide-directed ribosomal binding assay. 相似文献
108.
109.
Woodbury P. B. Arthur M. A. Rubin G. Weinstein L. H. McCune D. C. 《Water, air, and soil pollution》1999,110(3-4):421-432
Selenium, a potentially toxic trace element, is present in coal fly ash and is accumulated by plants growing on ash landfills. Application of gypsum (CaSO4·2H2O) can reduce Se accumulation. The persistence of this effect and the efficacy of repeated gypsum applications were investigated in forbs and grasses on a soil-capped, fly ash landfill near Lansing, New York. Gypsum was applied as a top-dressing at a rate of 0 or 11.2 t ha-1 in 1990 to three plots, and one-half of each of these plots received an additional top dressing of gypsum at 11.2 t ha-1 in 1991, producing four treatments – no gypsum, gypsum only in 1990, gypsum only in 1991, and gypsum in both years. Vegetation was harvested in July and October of 1991 and in July of 1992 and analyzed for Se, S, and Ca. Application of gypsum: (1) decreased Se accumulation by forbs and grasses harvested later in the season; (2) decreased Se accumulation in a subsequent year; (3) produced no further decrease when reapplied in a second year; and (4) did not decrease Se accumulation two years after a single application. The decrease in Se accumulation was not due to dilution caused by S fertilization. Variation in Se accumulation was not explained by variation in the pH and Se concentration of the soil and ash. 相似文献
110.
The juxtaposition of oil and gas wells against the Rocky Mountains on Colorado's Front Range provides a picture of the complicated interaction between Colorado's natural resources above and below ground. As hydraulic fracturing has increased oil and gas development—bringing jobs and money to an already highly sought after amenity‐rich area—it has also increased concerns about the impact on natural amenities, such as water quality and mountain views. Using data on housing sales between 2006 and 2014, we estimate how shale development is capitalized into housing prices in a booming market when households are in close proximity to other natural amenities. We find that shale development negatively impacts house prices, more so for houses with private water and houses that are closer to the mountains, but that competition for land along the Front Range has driven up house prices overall in the region. Our results also suggest the policy responses to shale development may differ for growing, amenity‐rich regions. 相似文献