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Water consumption by sheep in 48-h periods was measured in three replicated experiments. Intake was expressed as ml X kg body weight-.73 X d-1 and treatments were compared with intake of tap water or distilled water in no-choice situations. Neutralizing two acid mine drainage (AMD) polluted waters having pH values of 2.4 and 2.8, with Ca(OH)2 did not make either as acceptable to sheep as unpolluted water (P less than .01). Simulating AMD with sources of H+, HSO4-, SO4 =, Fe , Al++, Mn++, Zn++ or Na+ revealed several significant differences in acceptance. The ferric ion at 2.6 mM was rejected when presented as Fe2(SO4)3 but not as equimolar FeCl3. Moreover, SO4 = at 3.9 mM was not rejected when presented as Na2SO4 or ZnSO4. Neither AlSO4 nor MnSO4 at levels found in the two sources of AMD was rejected. Effects of prolonged consumption of the various components have not been determined.  相似文献   
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After vitrification of oocytes, fertilization rates and subsequent development are unsatisfactory, possibly due in part to zona hardening. Foetal calf serum (FCS) can prevent zona hardening because of its fetuin content, but FCS composition varies among batches, and may contain viruses. In this study, we therefore compared media supplemented with different sources of macromolecules, 2% bovine serum albumin (BSA), 2% BSA + 1 mg/ml fetuin and 20% FCS, for handling oocytes for 10–30 min prior to vitrification. None of the treatments resulted in developmental rates comparable with the non‐vitrified controls, but FCS inclusion in pre‐vitrification handling medium resulted in higher blastocyst production per oocyte (p < 0.05) (10.8%) on day 9 of culture than BSA (5.3%) or BSA + fetuin (6.4%). Blastocysts developing from oocytes from all vitrification treatments were somewhat retarded relative to those developed from non‐vitrified oocytes. We also tested the use of fetuin during vitrification as well as two different exposure times with cryoprotectants, 180 and 30 s. There was no significant effect of fetuin or exposure time on rates of subsequent blastocyst production.  相似文献   
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Three somatic hybrid lines between potato (cv. While Lady line no. Ke 79, 2n = 2x = 48) + Solanum brevidens (PI 218228, 2n = 2x = 24) were evaluated using randomly amplified polymorphic DNA (RAPD) markers. The lines originated from the same callus but showed different reactions to Erwinia carotovora ssp. carotovora, the cause of potato soft rot. By the use of 48 oligomer primers producing 99 scorable bands, DNA polymorphism were detected on 7 of 12 S. brevidens chromosomes. Loss of certain DNA segments on chromosome 5, 6, 9 and 11 were observed. Some of the variations could have taken place in early callus stage of development; others may have occurred after initiation of individual shoot regeneration. The possible involvement of missing RAPD products specific to one somatic hybrid that shows decreased resistance to bacterial soft rot is discussed.  相似文献   
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In the present study, phenotypic variability of 80 plum (Prunus domestica L.) varieties maintained in the French National Plum Collection was evaluated with 19 quantitative traits. In addition, genetic diversity and genetic structure was studied in three plum species (P. domestica L., Prunus cerasifera Ehrh. and Prunus spinosa L.) using chloroplast DNA (cpDNA) markers and five single sequence repeat (SSR) loci. Based on phenotypic traits, some varieties, such as mirabelle plums, grouped together. Bayesian structure analysis was used to identify different genetic groups, whereby damson plums were clearly distinguished from greengage plums. When examining the three species together, a higher level of cpDNA allelic richness was found in P. cerasifera and in P. spinosa than in P. domestica where only five cpDNA haplotypes were detected in the national plum collection, with one main haplotype that accounted for 80% of the varieties studied. P. domestica cpDNA haplotypes tended to group together with P. cerasifera haplotypes whereas most of P. spinosa haplotypes formed a separate cluster. SSR markers were somewhat able to distinguish the three species. These results provide some clues as to the origin of plum and the various plum varieties. Our results also provide useful information for the management of plum genetic resources.  相似文献   
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The investigation of genetically modified trees requires rapid and reliable techniques to measure the mechanical properties at an early age in order to give timely feedback to forest geneticists. In this study, transmittance near-infrared (NIR) spectroscopy was used to predict the green mechanical properties of 1- and 2-year-old transgenic and wild-type aspen. Green modulus of elasticity (MOE) in three-point bending and green ultimate compression strength (UCS) parallel to the grain were predicted from the NIR spectra of dry wood meal pellets. Green UCS had strong correlation (R 2 = 0.91) and green MOE had good correlation (R 2 = 0.78) with the spectra. The latter could be explained by the moderate correlation of MOE with the lignin content of the transgenic samples, suggesting that besides chemical composition MOE also depends on anatomical properties. The ratio of performance to deviation value suggested that the calibration model of both UCS (2.94) and MOE (1.91) could be used for screening.  相似文献   
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Pituitary-dependent hyperadrenocorticism was diagnosed in a 14-year-old Arabian mare with chronic weight loss, hirsutism, polyuria, and polydipsia. The mare had a stress leukogram, glucosuria, and consistent hyperglycemia. Plasma glucose concentrations were resistant to suppression by insulin. Plasma cortisol concentrations were within normal limits, but did not respond to dexamethasone suppression and had an exaggerated response to ACTH stimulation. At necropsy, a chromophobe adenoma of the pars intermedia of the pituitary gland was found. The zona fasciculata of the adrenal cortex and the pancreatic islets of Langerhans were hypertrophied. An immunohistologic staining technique was used to demonstrate ACTH-containing neoplastic cells in the pituitary mass. These cells released ACTH and other peptides that initiated the chain of endocrinologic events leading to clinical disease.  相似文献   
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