An Ecological Foodniche Concept as a Proxy for Fish-Pond Stocking Rates in Integrated Aquacultural Farming for Malaysia

The merits of integrated aquaculture farming (IAF) as a strategy for bolstering income for the rural poor have been recognized, but the economic efficiency and sustainability are yet to be determined. The effects of one species on another and the economic benefits, net of government support, have not been critically evaluated. The concept of a foodniche for alternative species in an aquatic environment has not been properly tested in an economic setting. Thus, this report reflects the results of applying the technique of mixed integer linear programming to determine the optimum combination of species within the context of a foodniche. The objective also included maximizing revenues, with minimal external input requirements, for a representative small Malaysian wet-rice farm. It was found that the foodniche concept permitted flexibility in stocking rates, and that farmers could actually stock species at the exact rate that was optimal for profit, instead of standard fixed rates. Also, government subsidies for pond construction were essential for IAF success. The net revenues from IAF were low without interest-free loans for pond construction.     

Experience with fireblight in the Czech Republic1

Erwinia amylovora has been spreading in the Czech Republic since 1986 regardless of emergency phytosanitary measures which have been taken. Its spread follows the predominant wind direction (west to east). The infested area now covers two thirds of the area of the country. Wild Crataegus spp. are the most important and widespread host plants. E. amylovora is still regulated as a quarantine pest, and areas free from fireblight are subject to special phytosanitary measures.     

VSV的RT-PCR快速检测方法的建立

选取水泡性口炎病毒 N基因序列 ,设计 1对引物 ,建立检测水泡性口炎病毒的 RT- PCR方法。对VSV各毒株进行检测 ,结果均为阳性 ,而对反刍动物病毒性疾病相关病毒进行检测 ,结果均为阴性。结果表明所建立的 RT- PCR技术可用于水泡性口炎的诊断和流行病学调查     

Analysis of a Long-term Experiment with Repeated-measurement Models

Long‐term experiments are a classical case of repeated measurements. Traits are measured on the same experimental unit over many years so that correlations arise between the observations made on the same plot in consecutive years. This paper describes the analysis of a three‐crop‐rotation long‐term experiment. We analysed the yields of the crops and the organic carbon content in the topsoil over 30 consecutive years. Several variance–covariance approaches are discussed and the trait‐specific best fit is interpreted. Mixed models are used to describe the structure of the experiment. Both yields and soil organic carbon show a more or less pronounced variance heterogeneity. Especially for yields, the heterogeneity of cycles and years is dominant. The consideration of correlations results in a better model fit in all cases.     

Agrogis: a computer‐based program for collecting information on pests of plants in Poland*

A computer system Agrogis has been developed to record information on pest infestation of plants in different regions of Poland. Data can be entered manually or from disks, and can be displayed in the form of charts and maps. Agrogis will be made available on the Internet.     

糖类寄生螨快速分离检验方法

本文对糖类寄生螨的快速分离检验方法进行了改进。将糖类溶解后，经过500目/英寸标准检验筛进行过筛分离。此方法对各种可溶性糖类中的寄生螨类能取得100％的快速分离检验结果。     

奶牛乳房炎多联苗(B)的临床免疫试验

用奶牛乳房炎多联苗 (B)免疫家兔 ,14 d血清中金黄色葡萄球菌抗体效价可达 1∶ 8,2 8d抗体水平明显升高 ,可达 1∶ 32 ,注苗后 35 d攻毒 ,攻毒后 2 d保护率为 93.3% (14 /15 ) ,自然保护率为 2 0 % (1/5 ) ,10 d保护率为 6 6 .6 % (10 /15 ) ,自然保护率为 2 0 % (1/5 ) ;用多联苗 (B)臀部肌肉注射免疫泌乳牛 ,试验期间 4个月内 ,3ml剂量组临床型乳房炎月平均发病率为 11.0 9% ,其对照组为 2 0 .19% ,发病率降低 4 5 .2 9% ,差异极显著 (P<0 .0 1) ;5 m l剂量组月平均发病率为 13.0 1% ,其对照组为 31.36 % ,发病率降低 5 8.5 1% ,差异极显著 (P<0 .0 1) ;3ml剂量组与 5 m l剂量组之间发病率无明显差异 (P>0 .0 5 ) ;注苗后泌乳牛血清抗体水平可持续 4个月 ,且 30 d时效价水平最高。