糖类和骤冷对红茶冷后浑形成的影响

研究了添加糖类和骤冷对红茶冷后浑形的影响，结果表明，还原糖抑制红茶冷后浑比非还原糖有效。还原糖中的双糖一旦与多糖作用结合后，对防止多酚类分子相互聚集具有立体障碍作用，其抑制冷后浑的效果优于单糖，淀粉促进茶汤冷后浑形成。冷后浑随冷却速率加快而增加．     

Effect of water quality on soil structure and infiltration under furrow irrigation

The quality of irrigation water has the potential to significantly affect soil structural properties, infiltration and irrigation application efficiency. While the effect of electrolyte concentration (as indicated by the electrical conductivity EC) and sodium adsorption ratio (SAR) have been studied under laboratory conditions, the effect on soil profile structural properties and irrigation performance have not been widely investigated under field conditions. In this paper, water with three different levels of sodium (SAR = 0.9, 10 and 30) was applied as alternative treatments to a clay loam soil. The application of 238–261 mm of medium- to high-SAR water was found to reduce aggregate stability, increase the bulk density of both the surface crust and underlying soil, and reduce the total depth of infiltration and final infiltration rate. Where low-SAR water was used, there was no significant (P<0.05) difference in final infiltration rate after the first four irrigations. However, where moderate- and high-SAR water was applied after the first four irrigations with the low EC-SAR water, the final infiltration rate was found to decrease on each of the successive irrigation events. For the moderate- and high-SAR treatments, this suggests that a steady-state equilibrium had not been reached within that part of the soil profile impeding infiltration. It is proposed that the initial reduction in infiltration is related to the physical processes of slaking leading to the development of an apedal, hardsetting surface soil layer. Similarly, it is proposed that the subsequent increase in bulk density and decline in infiltration where moderate and high EC-SAR water is applied is due to an increase in clay tactoid swelling reducing the size of the conducting micropores, dispersion blocking pores, and/or an increase in the thickness of the apedal surface layer. The reduction in infiltration associated with the use of high-SAR irrigation water was found to reduce the performance of the irrigations, with the application efficiency of the final irrigation decreasing from 40% where the low-SAR water was used, to 21% where the high-SAR water was applied. The implications for surface irrigating with water containing high sodium levels are discussed.Communicated by A. Kassam     

Zeranol and adult steers

Abstract

Extract

Madam:- The growth rate response obtained in yearling steer cattle to zeranol treatment have been extensively documented in New Zealand ⁽¹⁾ McKenzie, J.R. 1981. Effect of growth implants on sheep and cattle production. Proc. N.Z. Soc. An. Prod., 41: 294–296.  [Google Scholar] ⁽²⁾ McNerney, D.M. 1985. Effect of zeranol on beef steer growth rate in four geographical locations of New Zealand. N.Z. vet. J., 33: 19–19. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar] ⁽⁴⁾ Scales, G.H. 1984. Beef Cattle, Implants for Increased Production AgLink FPP 523, Wellington: N.Z. Ministry of Agriculture &; Fisheries.  [Google Scholar] and overseas literature. I wish to record the result of growth responses in two-year-old steer cattle.     

Suspected primary hematomyelia in 3 dogs

Primary hematomyelia refers to hemorrhage occurring within the spinal cord without an identifiable etiology. Clinical signs, magnetic resonance imaging characteristics, and histopathological findings are described. Diagnosis was made through histological analysis and rule-outs for underlying factors. Following removal of the hematoma, neurologic deficits improved, although some residual deficits persisted.     

An ELISA optimized for porcine epidemic diarrhoea virus detection in faeces

Monoclonal antibodies to porcine epidemic diarrhoea virus (PEDV) membrane protein M were prepared and used for the comparative assessment of three blocking ELISA variants to detect PEDV. The competitive blocking ELISA (CB-ELISA) format showed the highest sensitivity, allowing detection of 10(2.5) plaque-forming units of PEDV/ml in culture medium. Its specificity was verified by inclusion of control samples containing transmissible gastroenteritis virus (TGEV) and rotavirus A in each analysis. Eighty porcine field samples of faeces obtained from 38 herds affected with diarrhoea were examined, and PEDV was found in 15 (19%) samples from 6 (16%) herds. The suitability of the CB-ELISA for the screening herds in epizootiologic situations is discussed.