中国水仙R2R3-MYB基因NtMYB5的克隆和功能研究

为研究中国水仙（Narcissus tazetta var. chinensis）中类黄酮代谢途径的调控网络,从其转录组中筛选出1条R2R3-MYB基因并从花瓣cDNA中克隆其编码区全长序列,命名为NtMYB5。NtMYB5开放阅读框为681 bp,编码226个氨基酸。蛋白多重序列比对分析发现NtMYB5含有R2和R3结构域以及1个pdLNLD/ELxiG/S氨基酸基序;系统进化树分析表明,NtMYB5与花青素合成抑制因子亲缘关系最近;通过对NtMYB5在中国水仙中的表达检测发现,其表达量在花器官中较高,且随花开放逐渐上升;在烟草瞬时表达中,NtMYB5显著抑制花青素合成促进因子StMYB的效果;转NtMYB5烟草花瓣颜色变浅,qPCR检测表明NtMYB5抑制类黄酮代谢途径大部分结构基因表达。NtMYB5为中国水仙中花青素合成抑制因子。     

Effect of induced pyrexia on the disposition kinetics of ciprofloxacin in dogs

Ciprofloxacin was administered intravenously @ 5 mg/kg body weight to six healthy dogs. After a washout period of two weeks, fever was induced by injecting Escherichia (E) coli endotoxin. Ciprofloxacin was administered again. Blood samples were collected at various time intervals and analyzed for ciprofloxacin with HPLC. The kinetic analysis revealed the volume of distribution in healthy vs. febrile dogs as 2.12 ± 0.32 vs. 1.79 ± 0.43 L/Kg, respectively. The elimination half life was 2.23 ± 0.78 and 2.07 ± 0.74 hours in healthy and febrile dogs, respectively. Similarly, dogs under healthy and febrile conditions showed comparable total plasma clearance of 0.66 ± 0.06 and 0.60 ± 0.07 L/Kg/h, respectively. All these and other investigated kinetic parameters were statistically non significant. This study concludes that the pharmacokinetic behavior of ciprofloxacin is similar under healthy and febrile conditions. Thus, the kinetic studies of fluoroquinolones conducted in normal/healthy animals may be used to depict the pharmacokinetic parameters in diseased animals.     

A rare case of globosus amorphus in a goat

We present a case of globosus amorphus delivered from a goat and subjected to radiography and histological examination. Radiography revealed a lack of development of any organ system; histological sections showed evidence of lymphoid aggregations, mononuclear infiltrations, blood capillaries, and dense fibroblasts.     

Serum metabolites, milk yield, and physiological responses during the first week after kidding in Anglo-Nubian, Angora, Baladi, and Damascus goats under subtropical conditions

This study was carried out to determine the level of certain biochemical variables reflecting the energy metabolic statuses during the first week of lactation in goats. A total of 120 Anglo-Nubian, Angora, Baladi, and Damascus does (30 does per breed) were used throughout 5 consecutive parities (30 does per parity) to investigate the effect of breed, parity, day of lactation, and their interaction on serum metabolites including total protein, albumin, globulin, glucose, total lipids, cholesterol, and transaminases. Blood samples were collected every other day during the first week of lactation. Baladi does had the greatest (P < 0.001) values in all measured biochemical variables followed by Anglo-Nubian [in total protein, globulin, and aminotransferase (AST)] and Damascus (in globulin and AST) and then Angora, which had the lowest (P < 0.001) values for all variables. Fifth parity exhibited the greatest (P < 0.001) values in all serum metabolites compared with other parities except for alanine transaminase (ALT) enzyme activity in which the greatest (P = 0.046) values were observed in the first and fourth parties. Serum concentrations of the measured variables increased gradually throughout the first day after kidding until the seventh day for total protein (P < 0.001), albumin (P = 0.013), globulin (P = 0.017), and cholesterol (P = 0.028) whereas serum glucose concentration exhibited an opposite trend. Serum concentrations of total lipids and enzyme activities of AST and ALT were not affected by day (P > 0.05) after kidding. Baladi goats had the least (P < 0.001) serum insulin concentration, which was associated (P < 0.001) with greatest serum glucose concentration. Serum triiodothyronine (T(3)) was inversely correlated (P = 0.032) with milk yield whereas greatest (P = 0.003) T(3) concentrations were associated with least (P < 0.001) milk yield recorded in Angora goats. Animal physiological responses and their indices were not affected (P > 0.05) by breed whereas both rectal temperature and coefficient of heat tolerance were affected (P < 0.001) by parity in an opposite direction. Baladi goats expressed an aspect of adaptability where their rectal temperature decreased and coefficient of heat tolerance increased with increasing parity number.     

Capacitation of Frozen Thawed Buffalo Bull (Bubalus bubalis) Spermatozoa with Higher Heparin Concentrations

The present study was conducted to examine the effect of high heparin concentration on capacitation of buffalo spermatozoa with a short incubation time. Frozen thawed spermatozoa from three buffalo bulls were pooled and treated with either 50, 100 or 200 microg/ml heparin for 30 min. Capacitation was evaluated by acrosome reaction of spermatozoa and in vitro fertilization rate (per cent cleavage rate, per cent cleavage index). Acrosome reaction was induced in heparin treated spermatozoa with calcium ionophore A23187 and staining was carried out with Coomassie G-250 to evaluate the response as compared with control (0 heparin + calcium ionophore). Significantly higher percentage of acrosome reaction (AR) spermatozoa was noted after heparin treatment (36.8-48.2%) as compared with control (8.1% ; p < 0.05) but differences among the three heparin concentrations were non-significant. However, a significantly higher in vitro fertilization rate was recorded in spermatozoa capacitated by 50 and 100 microg/ml heparin (80.4 and 75.9% cleavage rate, respectively) as compared with 200 microg/ml heparin (47.2% cleavage rate; p < 0.001). It is concluded that buffalo spermatozoa capacitated with 50-100 microg/ml heparin had significantly higher ability to improve in vitro fertilization rate in buffalo.     

Arbuscular mycorrhizal inoculation has similar benefits to fertilization for Thuja occidentalis L. seedling nutrition and growth on peat soil over a range of pH: implications for restoration

New Forests - Arbuscular mycorrhizal (AM) fungi are hypothesized to assist growth of northern white-cedar in acid peatlands, yet there is little direct evidence that they can provide sufficient...     

Allelopathic effects of Mikania cordata on forest and agricultural crops in Bangladesh

Mikania cordata, an invasive weed is becoming a problem in the secondary degraded forests and plantations of Bangladesh, not only competing with but also releasing allelochemicals to cultivated crops. Allelopathic effects of the leaves of M. cordata were investigated through an experiment in the green house of the Institute of Forestry and Environmental Sciences, University of Chittagong, Bangladesh. Five economically important agricultural crops(Oryza sativa L., Triticum aestivum L., Vigna sinensis L., Abelmoschus esculentus L. and Amaranthus tricolor L.) and three forest crops(Acacia auriculiformis A.Cunn. ex Benth. Hook, Albizia procera(Roxb.) Benth.,and Paraserianthes falcataria(L.) Nielson) were used as bioassay species. Experiments were conducted on trays at an average room temperature 27 °C. The effects of different concentrations of leaf extracts were compared to controls. Water soluble allelochemicals of M. cordata inhibited the germination and initial growth of the tested agricultural and forest crops. Germination percent of forest crops declined with increasing concentration of extracts.The inhibitory effect on root elongation of forest crops was pronounced, whereas a stimulatory effect was found on P.falcataria up to a concentration of 25 %. Abelmoschus esculentus showed poor germination(%) and low shoot development(0.5 cm) and no development of taproot or lateral roots at treatment of 100 % concentration. Theinhibitory effect was proportional to the concentrations of the extracts with higher concentrations producing stronger inhibitory effects. Lower concentrations showed some stimulatory effect. The inhibitory effect was pronounced in root and lateral root development rather than germination or shoot development of the crops. Mikania cordata should be eradicated for healthy growth and development of the forest and adjacent agricultural crops.     

新疆山地针叶林乔木胸径-树高关系分析

树木的生长包括了径向生长和垂直生长两个方面,这两方面具有密切的关系,这一关系既受到树木本身的控制,同时也受森林立地条件的影响.通过分析新疆阿尔泰山、天山南北坡以及昆仑山区11个地点120个样方的胸径-树高关系.结果表明:昆仑山的尖削度(taper)显著大于其余3地,其潜在最大树高(potential height,H*...     

Secondary Effluent Treatment by Slow Sand Filters: Performance and Risk Analysis

The objective of this study is to examine the reuse of wastewaterfor beneficial purposes. To accomplish this objective, the efficiency of slow sand filters in removing total coliforms (TC) was studied using a probabilistic method. Three pilot scale slowsand filters were constructed at Alkhobar wastewater treatment plant, Dhahran, Saudi Arabia. The removal efficiency of filters was estimated under different operating control parameters, which included filtration rate (q), sand bed depth (d) and sand grain size (c). The Type III extreme value distribution best fitted theremoval efficiency data. A multiple linear regression analysis was performed to develop a relationship for mean removal efficiency as a function of control parameters. The predicted mean response and experimental results of previous studies werecompared to validate the empirical regression model. The controlparameters and influent concentrations of total coliform were used in Monte Carlo (MC) simulations for calculating the reliability index (β). The reliability index and corresponding risk were calculated for lognormally distributedsafety margins (SM). An effluent standard of 100 total coliform/100 mL was defined as capacity of the filter to ascertainthe risks of exceedence, which was approximately less than 50 for95% of the time. Pre and/or post disinfection would be necessaryto meet the stipulated effluent standards for unrestricted agriculture use.