The Water Dipole Moment in Water Clusters     

JK Gregory  DC Clary  K Liu  MG Brown  RJ Saykally 《Science (New York, N.Y.)》1997,275(5301):814-817

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免耕和常规耕作农田生态系统冬季覆盖作物残茬分解和养分变化   总被引：3，自引：0，他引：3  

吴珊眉  G. J. House  韩纯儒 《土壤学报》1986,23(3):204-211

免耕和常规耕作农田生态系统冬季覆盖作物红三叶草和黑麦草残体分解的格局和养分释放速率有明显区别.免耕地面残体养分释放和生物固定作用均缓于常规掩埋残体.常规耕作下,残体在掩埋后十天,C:N比值仍高时,红三叶草和黑麦草残体养分元素降低率,氮素分别为32.0%和52.0%、磷素为62.1%和78.3%、钾素为92.5%和91.2%、钙素为84.3%和61.2%、镁素为65.0%和75.2%.在分解早期,养分“损失”可能是由机械作用所加速的,如切碎、压榨、汁液外渗、扩散和淋洗作用等等.文中最后提出了减少残茬中早期养分过速“释放”的对策.  相似文献   

Diarrhoea due to trichostrongylid larvae in Merino sheep - repeatability and differences between bloodlines     

JWA LARSEN  AL VIZARD  JK WEBB WARE  N. ANDERSON 《Australian veterinary journal》1995,72(5):196-197

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Laboratory diagnosis of African horse sickness: comparison of serological techniques and evaluation of storage methods of samples for virus isolation   总被引：1，自引：0，他引：1  

C House  P E Mikiciuk  M L Berninger 《Journal of veterinary diagnostic investigation》1990,2(1):44-50

Five serological methods of diagnosing African horse sickness were evaluated, using a battery of serum samples from experimental horses vaccinated and challenged with each serotype of African horse sickness virus (AHSV1 through AHSV9): agar gel immunodiffusion (AGID), indirect fluorescent antibody (IFA), complement fixation (CF), virus neutralization (VN), and enzyme-linked immunosorbent assay (ELISA). The 5 tests were also compared using a panel of field samples, convalescent equine sera with antibodies to domestic equine viral diseases, and sera from horses awaiting export. The ELISA described in this paper was group specific. It did not require calibration with a standard positive serum but did yield elevated values with negative sera that were repeatedly frozen and thawed or heat inactivated. The IFA test was sensitive but could not be used on some field sera as the control cells exhibited fluorescence, possibly due to the animal being recently vaccinated with cell culture material. Sixty-two experimental sera were compared by VN, CF, AGID, and ELISA. Forty sera, 10 positive and 30 negative, were correctly classified by the 5 serologic assays. The 22 remaining sera gave mixed reactions. The AGID had no false positive results but had false negative results for up to 20% of the samples, depending upon the comparison. The VN, CF, and ELISA were similar in their variability. The length of time that virus could be recovered from a viremic blood sample was compared in an evaluation of storage methods for virus isolation samples. Washed erythrocytes were held at 4 C, washed erythrocytes plus stabilizer were held at -70 C, and blood that was drawn into a preservative (oxalate/phenol/glycerol) was held at 4 C.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Hemochromatosis in Salers Cattle     

John K. House BVMS    Bradford P. Smith  John Maas  V. Michael Lane  Bruce C. Anderson  Thomas W. Graham  Michael V. Pino 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1994,8(2):105-111

Two 2-year-old Salers cattle from different herds raised on pasture were evaluated for retarded growth and diarrhea. Increase of liver enzyme activities and prolonged sulfobromophothalein (BSP) half life (T1/2) indicated liver disease with impaired liver function. Histopathologic examination of liver biopsies revealed a micronodular cirrhosis with marked deposition of hemosiderin in hepatocytes, Kupffer cells, and arterioles. Transferrin saturation (TS) and liver iron content were markedly increased, consistent with a diagnosis of hemochromatosis. Both animals were euthanatized due to deterioration in their condition. Necropsy findings included hepatomegaly and hemosiderin accumulation in the liver, lymph nodes, pancreas, spleen, thyroid, kidney, brain and other glandular tissue. Continued surveillance of the second herd (serum iron, total iron binding capacity [TIBC], unsaturated iron binding capacity [UIBC], and TS), identified a heifer as a hemochromatosis suspect in a subsequent generation. Liver biopsies from that animal revealed the same histopathologic changes as the previous 2 animals, and similar increases in liver iron content (8,700 ppm, normal range 45 to 300 ppm). The 3 affected cattle were all products of line breeding programs and shared a common ancestor. The absence of dietary iron loading in conjunction with the histopathologic and metabolic findings were consistent with a diagnosis of primary hemochromatosis. The reported disease is similar to idiopathic hemochromatosis in human beings in which there is a hereditary defect in iron metabolism.  相似文献   

Evaluation of techniques to demonstrate foot-and-mouth disease virus in bovine tongue epithelium: comparison of the sensitivity of cattle, mice, primary cell cultures, cryopreserved cell cultures and established cell lines     

C House  J A House 《Veterinary microbiology》1989,20(2):99-109

Tongue epithelia infected with each of the 7 serotypes of foot-and-mouth disease virus (FMDV) were used to evaluate in vivo and in vitro systems for the detection of FMDV. Cattle inoculated by the intradermal route in the tongue (IDL) and suckling mice inoculated intraperitoneally were compared for susceptibility to FMDV with freshly prepared bovine thyroid cell cultures; cultures from cryopreserved bovine thyroid, bone marrow, mammary gland, myocardium, tongue, ovary and kidney cells; cultures from cryopreserved embryonic ovine kidney, newborn ovine kidney, ovine testicle, bone marrow, and chloroid plexus cells; and the continuous porcine kidney cell lines MVPK-1 and S6. The mean titers determined for each serotype in each system were statistically compared. The FMDV titers obtained in freshly prepared bovine thyroid cell cultures and by cattle IDL inoculation were the highest and were statistically indistinguishable. The titers obtained by suckling mouse inoculation were significantly lower than the titers obtained in thyroid cultures for serotypes A, C, Asia 1, and SAT 3. The cattle IDL assay was significantly more sensitive than the mouse assay for serotype A. The cell cultures from the cryopreserved newborn ovine kidney and embryonic ovine kidney were significantly less susceptible to serotype Asia 1 when compared with the fresh bovine thyroid cultures, but not significantly different when compared with the cattle assay for all serotypes. Cryopreservation of bovine thyroid cells directly after trypsinization resulted in the loss of susceptibility to FMDV serotype SAT 2. The other cryopreserved cell culture systems exhibited no or minimal susceptibility to all 7 serotypes, or exhibited considerable inconsistency. The established cell lines MVPK-1 and S6 were not susceptible to serotype A, and were less sensitive to serotype C than other culture systems. Quality control of cell cultures used to evaluate field specimens for FMDV was critical. The cell cultures of cryopreserved ovine kidney cells provided the most practical diagnostic system.  相似文献   

Development of an immunoelectroosmophoresis test for the detection and typing of antibodies to vesicular stomatitis viruses.          下载免费PDF全文

C R Wilks  E W Jenney    J A House 《Canadian journal of veterinary research》1984,48(2):179-183

This study was conducted to develop a rapid test to detect type specific antibodies to various strains of vesicular stomatitis virus. Glycoprotein was extracted from purified vesicular stomatitis virus-Indiana 3 and used as antigen in an immunoelectroosmophoresis test (counter immunoelectrophoresis) to test reactivity with homologous hyperimmune serum and antisera to vesicular stomatitis virus-New Jersey, Indiana 1 and Indiana 2. A reaction was only detected with the homologous antiserum. A simpler preparation of antigen, a detergent extract of infected cells was also evaluated and shown to have less specificity in reactions with hyperimmune sera. This infected cell extract was, however, useful in detecting homologous antibodies in convalescent sera (natural vesicular stomatitis virus-New Jersey infection) and no reactions were detected with infected cell extracts of vesicular stomatitis virus-Indiana 1, 2 and 3.  相似文献   

Meat composition and palatability of Holstein and beef steers as influenced by forage type and protein source.   总被引：1，自引：0，他引：1  

E W Mills  J W Comerford  R Hollender  H W Harpster  B House  W R Henning 《Journal of animal science》1992,70(8):2446-2451

This experiment determined meat composition and palatability changes resulting from feeding Holstein (HOL) and crossbred beef (XB) steers diets containing corn silage (CS) or alfalfa haylage (AH) (forage type) and soybean meal (SM) or fish meal (FM) (protein source). Fifty-nine steers (30 HOL and 29 XB) were randomly assigned to diet combinations for a 2 x 2 x 2 (breed x forage x protein) factorial arrangement. Steers were fed to a fat-constant end point (fat depth over the longissimus muscle measured by ultrasound: 1.0 cm XB, .6 cm HOL). Proximate and fatty acid analysis and sensory evaluation were conducted on a rib eye roast and steaks, respectively, removed from the left side of each carcass at ribs 9 to 12. Proximate analysis of the longissimus muscle showed no significant difference (P greater than .05) in moisture, protein, or fat content due to breed, forage, or protein treatment. Forage type had no significant effect (P greater than .05) on amount of individual fatty acids found in longissimus muscle. However, total polyunsaturated fatty acids were higher (P greater than .05) for AH than for CS-fed animals. Longissimus muscle from steers fed FM had higher palmitoleic and lower stearic acid contents (both P less than .05) than longissimus muscle from animals fed SM. Muscle from HOL had higher palmitoleic and lower stearic acid contents than that from XB steers (both P less than .05). There was no significant interaction (P greater than .05) of breed with either diet treatment for individual fatty acid contents.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Transport and distribution of lindane and simazine in a riverine environment: measurements in bed sediments and modelling     

Allan IJ  House WA  Parker A  Carter JE 《Pest management science》2004,60(5):417-433

Aquatic sediments often remove hydrophobic contaminants from fresh waters. The subsequent distribution and concentration of contaminants in bed sediments determines their effect on benthic organisms and the risk of re-entry into the water and/or leaching to groundwater. This study examines the transport of simazine and lindane in aquatic bed sediments with the aim of understanding the processes that determine their depth distribution. Experiments in flume channels (water flow of 10 cm s(-1)) determined the persistence of the compounds in the absence of sediment with (a) de-ionised water and (b) a solution that had been in contact with river sediment. In further experiments with river bed sediments in light and dark conditions, measurements were made of the concentration of the compounds in the overlying water and the development of bacterial/algal biofilms and bioturbation activity. At the end of the experiments, concentrations in sediments and associated pore waters were determined in sections of the sediment at 1 mm resolution down to 5 mm and then at 10 mm resolution to 50 mm depth and these distributions analysed using a sorption-diffusion-degradation model. The fine resolution in the depth profile permitted the detection of a maximum in the concentration of the compounds in the pore water near the surface, whereas concentrations in the sediment increased to a maximum at the surface itself. Experimental distribution coefficients determined from the pore water and sediment concentrations indicated a gradient with depth that was partly explained by an increase in organic matter content and specific surface area of the solids near the interface. The modelling showed that degradation of lindane within the sediment was necessary to explain the concentration profiles, with the optimum agreement between the measured and theoretical profiles obtained with differential degradation in the oxic and anoxic zones. The compounds penetrated to a depth of 40-50 mm over a period of 42 days.  相似文献   

Effect of a commercial anion dietary supplement on acid-base balance, urine volume, and urinary ion excretion in male goats fed oat or grass hay diets     

Stratton-Phelps M  House JK 《American journal of veterinary research》2004,65(10):1391-1397

OBJECTIVE: To determine whether feeding a commercial anionic dietary supplement as a urinary acidifier to male goats may be useful for management of urolithiasis. ANIMALS: 8 adult sexually intact male Toggenburg, Saanen, and Nubian goats. PROCEDURE: Goats were randomly assigned by age-, breed-, and weight-matched pairs to an oat or grass hay diet that was fed for 12 days. On days 13 to 14 (early sample collection time before supplementation), measurements were made of blood and urine sodium, potassium, calcium, magnesium, chloride, phosphorus, and sulfur concentrations; blood and urine pH; urine production; and water consumption. During the next 28 days, the anionic dietary supplement was added to the oat and grass hay diets to achieve a dietary cation-anion difference of 0 mEq/100g of dry matter. Blood and urine samples were analyzed during dietary supplementation on days 12 to 13 (middle sample collection time) and 27 to 28 (late sample collection time). RESULTS: Blood bicarbonate, pH, and urine pH of goats fed grass hay and goats fed oat hay were significantly decreased during the middle and late sample collection times, compared with the early sample collection time. Water consumption and urine production in all goats increased significantly during the late sample collection time, compared with the early sample collection time. CONCLUSIONS AND CLINICAL RELEVANCE: The anionic dietary supplement used in our study increases urine volume, alters urine ion concentrations, and is an efficacious urinary acidifier in goats. Goats treated with prolonged anionic dietary supplementation should be monitored for secondary osteoporosis from chronic urinary calcium loss.  相似文献