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41.
CC Chase TA Olson AC Hammond MA Menchaca RL West DD Johnson WT Butts 《Canadian Metallurgical Quarterly》1998,76(12):2967-2975
We conducted a multiyear study in two phases to determine preweaning performance traits of Senepol (S x S), Hereford (H x H), and reciprocal (S x H and H x S) F1 crossbred calves and feedlot performance and carcass characteristics of steers. In Phase I, from 1985 to 1989, data from S x S (n = 194), H x H (n = 383), and S x H (n = 120) calves were used. Numbers of S x S cows were increased during Phase I so that data from H x S (n = 74) calves could be included in Phase II (1990 to 1992) in addition to S x S (n = 118), H x H (n = 130), and S x H (n = 56) calves. Also during Phase II, feedlot performance and carcass characteristics were determined for S x S (n = 30), H x H (n = 26), H x S (n = 36), and S x H (n = 26) steers. In Phase I, S x S calves had heavier (P < .01) birth weights and heavier (P < .01) 205-d adjusted weaning weights than H x H calves. Birth weights of S x H calves were heavier (P < .01) than the mean of the purebred calves, but 205-d adjusted weaning weights did not differ (P > .10). In phase II, direct heterosis was 3.5% for birth weight (P < .05) and 5.1% for 205-d adjusted weaning weight (P < .01). Senepol maternal breed effects were 1.9 kg for birth weight (P < .10) and 37.9 kg for 205-d adjusted weaning weight (P < .01). Levels of direct heterosis, Senepol maternal breed effects, and Hereford direct breed effects were significant for most feedlot performance traits of steer calves that were fed to a common end point. Breeds did not differ (P > .10) for USDA yield and quality grades, and direct heterosis was not significant for Warner-Bratzler shear force. These results demonstrate significant levels of heterosis in preweaning performance between S x S and H x H calves and in feedlot performance of steers. Levels of heterosis were smaller and nonsignificant for most carcass traits including meat tenderness, which did not differ between S x S and H x H steers in this study. 相似文献
42.
The reversed-phase HPLC separation of fluorescent o-phthalaldehyde (OPA) derivatives has been applied to the assay of hepatic gamma-glutamylcysteine and glutathione (GSH) levels and the enzymes producing these peptides. The method has been compared to the assay using monobromobimane (MB) as the derivatizing agent. The OPA method has the advantage of faster derivatization, the lack of need to adjust the pH, isocratic separation and selectivity for GSH and gamma-glutamylcysteine. The MB method requires pH adjustment following derivatization and gradient elution chromatography. MB is also non-selective, yielding fluorescent derivatives of all biological thiols and more interfering peaks on the chromatogram. MB-based analyses are also approximately sixty times more expensive per sample. MB yields fluorescent degradation products on exposure to light. OPA adducts are stable for up to ten days when stored at -20 degrees C. OPA detection is sensitive to 12.5 pmol in the sample, at a signal-to-noise ratio of 2.5. The two methods correlate well. Hepatic gamma-glutamylcysteine synthetase in the same liver preparation was found to be 4.85 +/- 0.47 nmol min-1 mg-1 protein by the OPA method and 4.42 +/- 0.52 nmol min-1 mg-1 protein by the MB method. GSH concentrations were found to be 90.4 +/- 6.5 nmol/mg protein for the OPA method and 92.5 +/- 3.4 for the MB method. 相似文献
43.
Relationship between mutagenic activity of drinking water and incidence of liver cancer was studied in Fusui County with micronucleus technique in the root tips of vicia faba. Results showed there existed substance that caused chromosome aberration in the drinking pond water of Fusui County. Micronucleus effects on the root tips of vicia faba induced by the substance in different kinds of drinking water coincided with the incidence of liver cancer (r = 0.86, P < 0.05). It suggested the existence of these chemical mutants in the water may be one of the important factors that caused high incidence of liver cancer. It provided experimental evidence for the etiological theory of liver cancer caused by the pollution of drinking water. 相似文献
44.
Central temperature is usually tightly regulated in human beings. Anesthesia alters the normal thermoregulatory controls of the body. Intraoperatively, mild degrees of hypothermia may provide some cerebral protection. However, the risk of organ dysfunction and shivering require that the anesthesiologist be prepared to treat severe hypothermia. Appropriate measures such as warning the operating room and using forced air blankets can prevent both intraoperative hypothermia and postoperative shivering. The use of temperature measurement is not limited to the operative and immediate recovery periods. Anesthesiologists practicing in intensive care units and in pain clinics use temperature monitoring as a diagnostic tool in a variety of situations. 相似文献
45.
BACKGROUND: Tumour necrosis factor alpha (TNF-alpha) is a proinflammatory cytokine found in abundance in diseased intestine. AIMS: The T cell production of TNF-alpha and the impact of this cytokine on intestinal T cell proliferation, migration, and cytotoxicity were studied. METHODS: Intestinal lymphocytes from normal jejunum were used. TNF-alpha production in culture supernates was measured by enzyme linked immunosorbent assay (ELISA). Lymphocyte proliferation was measured using 3H thymidine uptake; migration, using transwell chambers; and cytotoxicity of HT-29 colon cancer cells, using the chromium-51 release assay. RESULTS: TNF-alpha was produced mainly by the CD8+ T cells in the intraepithelial lymphocytes (IEL) and the CD4+ T cells in the lamina propria lymphocytes in response to CD2 stimulation: 478 (94) and 782 (136) pg/ml, respectively. TNF-alpha (1 ng/ml or greater) augmented proliferation of IEL in response to interleukin 2 (IL-2), IL-7, or antibody to CD3 due to increased activation that did not involve IL-2 production or receptor generation. Conversely, antibody to TNF-alpha reduced IEL proliferation in response to IL-2 or IL-7. TNF-alpha also induced calcium mobilisation and chemokinesis (by 2.8 (0.5) fold over spontaneous migration). TNF-alpha had no effect on lymphokine activated killer cell activity. CONCLUSIONS: TNF-alpha increases the proliferation and migration of IEL, which may expand their number in the epithelium. 相似文献
46.
Cleyo Harris Travis O. Brenden Chris S. Vandergoot Matthew D. Faust Seth J. Herbst Charles C. Krueger 《Journal of Great Lakes research》2021,47(1):48-58
Infrequent captures of invasive, non-native grass carp (Ctenopharyngodon idella) have occurred in Lake Erie over the last 30+ years, with recent evidence suggesting wild reproduction in the lake’s western basin (WB) is occurring. Information on grass carp movements in the Laurentian Great Lakes is lacking, but an improved understanding of large-scale movements and potential areas of aggregation will help inform control strategies and risk assessment if grass carp spread to other parts of Lake Erie and other Great Lakes. Twenty-three grass carp captured in Lake Erie’s WB were implanted with acoustic transmitters and released. Movements were monitored with acoustic receivers deployed throughout Lake Erie and elsewhere in the Great Lakes. Grass carp dispersed up to 236 km, with approximately 25% of fish dispersing greater than 100 km from their release location. Mean daily movements ranged from <0.01 to 2.49 km/day, with the highest daily averages occurring in the spring and summer. The Sandusky, Detroit, and Maumee Rivers, and Plum Creek were the most heavily used WB tributaries. Seventeen percent of grass carp moved into Lake Erie’s central or eastern basins, although all fish eventually returned to the WB. One fish emigrated from Lake Erie through the Huron-Erie Corridor and into Lake Huron. Based on our results, past assessments may have underestimated the potential for grass carp to spread in the Great Lakes. We recommend focusing grass carp control efforts on Sandusky River and Plum Creek given their high use by tagged fish, and secondarily on Maumee and Detroit Rivers. 相似文献
47.
48.
S. Travis Waller David Fajardo Melissa Duell Vinayak Dixit 《Networks and Spatial Economics》2013,13(4):427-443
This work introduces a novel formulation of system optimal dynamic traffic assignment that captures strategic route choice in users under demand uncertainty. We define strategic route choice to be that users choose a path prior to knowing the true travel demand which will be experienced (therefore users consider the full set of possible demand scenarios). The problem is formulated based on previous work by Ziliaskopoulos (Transp Sci 34(1):37–49, 2000). The resulting novel formulation requires substantial enhancement to account for path-based flows and scenario-based stochastic demands. Further, a numerical demonstration is presented on a network with different demand loading profiles. Finally, model complexity, implications on scalability and future research directions are discussed. 相似文献
49.
Travis Gagie 《Information Processing Letters》2008,108(6):418-421
Sorting is a classic problem and one to which many others reduce easily. In the streaming model, however, we are allowed only one pass over the input and sublinear memory, so in general we cannot sort. In this paper we show that, to determine the sorted order of a multiset s of size n containing σ?2 distinct elements using one pass and o(nlogσ) bits of memory, it is generally necessary and sufficient that its entropy H=o(logσ). Specifically, if s={s1,…,sn} and si1,…,sin is the stable sort of s, then we can compute i1,…,in in one pass using O((H+1)n) time and O(Hn) bits of memory, with a simple combination of classic techniques. On the other hand, in the worst case it takes that much memory to compute any sorted ordering of s in one pass. 相似文献
50.
Straub C Pazdrak K Young TW Stafford SJ Wu Z Wiktorowicz JE Haag AM English RD Soman KV Kurosky A 《Proteomics. Clinical applications》2009,3(10):1151-1173
Eosinophils (EOSs) are granular leukocytes that have significant roles in many inflammatory and immunoregulatory responses, especially asthma and allergic diseases. We have undertaken a fairly comprehensive proteomic analysis of purified peripheral blood EOSs from normal human donors primarily employing 2‐DE with protein spot identification by MALDI‐MS. Protein subfractionation methods employed included IEF (Zoom® Fractionator) and subcellular fractionation using differential protein solubilization. We have identified 3141 proteins, which had Mascot expectation scores of 10?3 or less. Of these 426 were unique and non‐redundant of which 231 were novel proteins not previously reported to occur in EOSs. Ingenuity Pathway Analysis showed that some 70% of the non‐redundant proteins could be subdivided into categories that are clearly related to currently known EOS biological activities. Cytoskeletal and associated proteins predominated among the proteins identified. Extensive protein posttranslational modifications were evident, many of which have not been previously reported that reflected the dynamic character of the EOS. This data set of eosinophilic proteins will prove valuable in comparative studies of disease versus normal states and for studies of gender differences and polymorphic variation among individuals. 相似文献