Diversity of Cryphonectria parasitica in western Spain and identification of hypovirus‐infected isolates

Isolates of the chestnut blight fungus Cryphonectria parasitica were obtained from 44 localities in four provinces in Western Spain and characterized for vegetative compatibility (vc) types, mating types and the presence of Cryphonectria hypovirus 1 (CHV1). Among the 1232 isolates recovered from chestnut blight cankers, 11 vc types were identified: five known vc types included in EU1 to EU74 (EU1, EU11, EU12, EU28 and EU66) and six unknown vc types (CL4, CL5 CL6, CL8, CL9 and CL10). The number of vc types found per province varied between two and seven. The vc type EU11 was present in all provinces and accounted for 48.9% of all isolates. EU1 was detected in three provinces and accounted for 39.1% of the isolates. The vc types EU12, EU66, CL5 and CL6 were present in one or two provinces and comprised between 2.4% and 3% of the isolates. The other vc types were represented by only one or very few isolates. The mating type MAT‐1 was largely dominant in the provinces Leon and Avila, while both mating types MAT‐1 and MAT‐2 were found in Salamanca and Zamora. Fourteen hypovirus‐infected C. parasitica isolates were found, nine were in vc type EU1 and five in EU11, and they were detected only in the province León. All isolates analysed contained the French hypovirus subtype CHV1‐F1.     

Effect of exposure to a country liquor (Toddy) during gestation on lipid metabolism in rats

The objective of this study was to determine theeffects of country liquor Toddy and its equivalentquantity of ethanol on lipid metabolism duringgestation in rats. Female rats weighing an average of125 g were exposed to Toddy (24.5 ml/body weight/day)and ethanol (0.52 ml/kg body weight/day) for 15 daysbefore conception and throughout gestation. On the19th day of gestation, altered liver function andhyperlipidemia was seen in both the treated groups.Altered liver function was evidenced by the increasedactivity of alcohol dehydrogenase, aldehydedehydrogenase, glutamic oxaloacetic transaminase oraspartate amino transferase (GOT), glutamic pyruvictransaminase or alanine amino transferase (GPT) andgamma glutamyl transpeptidase (GGT). Hyperlipidemiawas caused by increased biosynthesis and decreaseddegradation of lipids. The incorporation of ¹⁴Cacetate in lipids and activities of HMG CoA reductaseand lipogenic enzymes were elevated and activity ofLPL and bile acids contents were decreased. Toddytreated rats were more severely affected than thosereceiving an equivalent quantity of ethanol. Toddyseemed to potentiate the toxicity induced by alcoholindicating the role of the nonethanolic portion.Hepatic functions were also affected.     

Prediction of irrigation return flows through a hierarchical modeling approach

The quantity of water available for irrigation is getting scarce in many countries and it assumes great importance for assured crop production, especially in view of the erratic behavior of the monsoon. Thus, there is a pressing need to improve the water efficiency of irrigation systems. One-way of improving the efficiency of the irrigation system is reusing the return flow from the irrigation system. This task requires quantification of return flow, which still remains as a grey area in irrigation water management. The estimation of return flow from the irrigation system is usually obtained using thumb rules depending upon the site-specific conditions like command area conditions and soil properties. In this paper, a hierarchical modeling technique, namely, regression tree is developed for return flow estimation. Regression tree is built through binary recursive partitioning. The effective rainfall, inflow, consumptive water demand, and percolation loss are taken as predictor variables and return flow is treated as the target variable. The applicability of the hierarchical model is demonstrated through a case study of Periyar-Vaigai Irrigation System in Tamil Nadu, India. The model performance shows a good match between the simulated and the field measured return flow values. Results of statistical analysis indicated that the correlation coefficients are high for both single as well as double crop seasons.     

Continuous infusion of gentamicin into the tarsocrural joint of horses

OBJECTIVE: To develop a method for continuous infusion of gentamicin into the tarsocrural joint of horses, to determine pharmacokinetics of gentamicin in synovial fluid of the tarsocrural joint during continuous infusion, and to evaluate effects of continuous infusion of gentamicin on characteristics of the synovial fluid. ANIMALS: 12 healthy adult horses. PROCEDURE: An infusion catheter consisting of flow control tubing connected to a balloon infuser was used. Gentamicin solution (100 mg/ml) was infused in the right tarsocrural joint and balanced electrolyte solution was infused in the left tarsocrural joint for 5 days. Synovial fluid and serum gentamicin concentrations were measured by use of a fluorescence polarization immunoassay. RESULTS: 17 of the 24 (71%) infusion catheters initially placed functioned without complications for the entire 5-day infusion period. Median gentamicin concentration in synovial fluid from treated joints during the 5-day infusion period ranged from 2875 to 982 microg/ml. Median serum gentamicin concentration during this period ranged from 2.31 to 2.59 microg/ml. Mean (+/- SD) elimination half-life and total clearance of gentamicin from the synovial fluid were 6.25+/-1.01 hours and 1.52+/-0.96 ml/min, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: An infusion catheter can be used for continuous infusion of gentamicin into the tarsocrural joints of horses for up to 5 days. At a gentamicin dosage of 0.17+/-0.02 mg/kg/h, continuous intra-articular infusion results in synovial fluid gentamicin concentrations greater than 100 times the minimal inhibitory concentration reported for common equine pathogens.     

Lethal concentration of Cymbopogon citratus (Poaceae) essential oil for Dolops discoidalis and Argulus sp. (Crustacea: Argulidae)

This study investigated the acute toxicity (LC_50-24 hr) effects of the essential oil of Cymbopogon citratus for adult Argulus sp. and Dolops discoidalis, before and during oviposition. In vitro acute toxicity (LC_50-24 hr) was tested using 20, 40, 60, 80, 100, 120, 140 and 160 μg/L of C. citratus essential oil, and two control groups (one with cultivation tank water and one with cultivation tank water + alcohol) were used. Specimens of Argulus sp. and D. discoidalis submitted to acute toxicity were evaluated using histological procedures. The major chemical compounds of C. citratus essential oil were geranial (47.5%), neral (35.6%) and myrcene (6.7%). The LC_50-24 hr for Argulus sp. adults was 67.97 μg/L, while for D. discoidalis it was 59.55 µg/L. In the oviposition of both species of argulids, maximum mortality began with treatments of 140 μg/L, while the LC_50-24 hr for Argulus sp. and D. discoidalis was 83.98 μg/L and 82.48 μg/L, respectively. In both argulid species exposed to C. citratus essential oil, morphological alterations were observed only in the eyes, and they occurred in the ommatidium and rhabdomeres and were dependent on the concentration of C. citratus essential oil and the parasite species.     

岷江上游典型流域植被水文效应模拟

该文通过研究现有土地覆盖下水文分布的空间格局,及不同植被类型集水区内降雨与径流间的关系,来揭示森林生态系统与水文动态之间相互作用的机制,从而为岷江上游的生态环境评价和区域生态环境保护及恢复提供理论依据和科学指导.在前人研究的基础上,结合先进的地理信息系统和遥感技术,构建岷江流域植被水文模型.模型以水文子模块TOPMODEL为中心,由山地小气候模型MTCLIM和林冠截留模型为其提供水文学参数,研究中水文循环过程涉及植被截留、(实际)蒸散发、降雨入渗和土壤水分动态等.最后将模型应用于岷江上游典型支流——杂古脑流域,对其1995年7—9月的径流特征进行了模拟分析.结果显示,7—9月日径流量总体趋势表现为逐渐降低,径流量对降水响应敏感,基本反映了杂古脑流域雨季的径流变化特征.