Antifungal and larvicidal activities of two acyclic monoterpenes; citral and geraniol against phytopathogenic fungi and insects

Abstract

Citral and geraniol are dominating constituents of lemon and rose scented essential oils of Cymbopogon spp. Here, we report their antifungal activity against some pathogenic fungi Drechslera oryzae, Fusarium oxysporum, Rhizoctonia solani and Sclerotium rolfsii and larvicidal activity against two insects Helicoverpa armigera and Spodoptera litura. Results revealed that both citral and geraniol exhibited strong fungicidal effects at concentrations > 0.2 µL mL^?1. Citral was found most active against F. oxysporum and S. rolfsii while geraniol against S. rolfsii at 0.2–2 µL mL^?1. Nanoemulsions of citral and geraniol caused 91 and 94% larval mortality of H. armigera and S. litura, respectively, at 1% concentration. Hence, the study revealed potential antifungal and larvicidal activities of citral and geraniol, which can be implicated in formulation of biocides for effective control of phytopathogenic fungal and insects.     

Captive breeding of endangered fish Chitala chitala (Hamilton-Buchanan) for species conservation and sustainable utilization

Over the last few decades wild population of Chitala chitala (HamiltonBuchanan) has been declined more than 50% due to various reasons and is presently listed under endangered (EN) category due to reduced abundance. In the present communication wild C. chitala were collected from natural habitats and induced to spawn under captivity during July 2002 by injecting three different doses of synthetic hormone Ovaprim. Intramuscular injections were administered to fishes using three different doses (1.5, 1.0 and 0.5 ml/kg body weight). Artificial breeding pool was prepared for each set by encircling area (20 × 5 m) with mosquito net, where wooden country boat (8 × 4 × 2.5 feet with surface area 48.5 sq. feet) was placed inside the breeding pool. Distinct spawning behavior was noticed in the experimental sets with different hormonal dose whereas no spawning activity was noticed in control set. The fertilization rate varied from 48.8680.2% and total numbers of spawned eggs in two sets of experiments were estimated to be 81,034. The average number of eggs deposited 15 ± 2.1/square inches. The fertilized eggs were large in size (4.5 ± 0.05 mm), adhesive and attached to the hard substratum. The eggs hatch out between 168192 h after fertilization and about 33,639 hatchlings were produced. Newly hatched larvae measured 10.23 ± 0.03 mm and 0.031± 0.008 gm in weight and the mean diameter of yolk sac was 4.1 ± 0.08 mm. The yolk sac remains attached up to a week. The percentage survival of hatchlings varied from 42.2 to 65.60. Statistical analysis was worked out to determine the relation between the hormone dosage with different breeding parameters like latency period, fertilization rate, egg output, hatching rate and hatchling production.     

Homogeneous Agent-Based Distributed Information Filtering

Recent advances in processor, networking and software technologies have made distributed computing a reality in today's world. Distributed systems offer many advantages, ranging from a higher performance to the effective utilization of physically dispersed resources. Many diverse application domains can benefit by exploiting principles of distributed computing. Information filtering is one such application domain. In this article, we present a design of a homogeneous distributed multi-agent information filtering system, called D-SIFTER. D-SIFTER is based on the language-dependent model of Java RMI. The detailed design process and various experiments carried out using D-SIFTER are also described. The results indicate that the distributed inter-agent collaboration improves the overall filtering performance.     

Localization of DnaK and GroEL in Vibrio cholerae

Though the GroEL and DnaK heat shock proteins are well characterized in prokaryotes, only scanty and controversial information exist about their cellular localization. In the present study, the localization of the heat shock proteins DnaK and GroEL in normal and heat shocked cells of Vibrio cholerae, was investigated both by immunogold labeling of ultrathin sections and biochemical methods. Much of the DnaK was found to be localized at the inner membrane in unstressed cells, most probably at the Bayer's adhesion sites. Data suggested that upon heat shock, the DnaK associated with the membrane continued to remain there, but the newly synthesized DnaK appeared mostly in the cytoplasm. GroEL in both stressed and unstressed cells was found mainly in the cytoplasm.     

印度北方河流中主要鲤科鱼类卡拉(鱾)的年龄和生长

为了获得印度北部赣达(Ganga)盆地河流中野生卡特拉(鱾)种群的年龄结构和重要生长参数,对该鱼的年龄和生长进行了研究.鳞片取自商业捕捞和实验室饲养的样品.根据研究分析,该鱼最大年龄可达8龄;巴吉拉蒂河(Bhagirathi R.)的种群平均体长为521.51 mm,退算体长为288.9-1132.3 mm;旁遮普邦(Punjab)Satluj河种群平均体长为641.6 mm,退算体长为335.4-1096.08 mm.2龄时,种群线性生长率(Cl)和体重增加率(Cw)表现出迅速下降的趋势.其它生长参数值(Clt)也呈现快速下降.退算体长差异(ANOVA)分析显示,生活在赣达盆地不同流域中的种群,1 -4 龄组的长度差异较明显(P<0.05),高龄组(5 -8 )差异不显著.根据本项研究结果,提出了对印度北部赣达盆地相关河流中生活的野生卡特拉(鱾)种群资源持续利用的对策.     

Optimization of immunogold labeling TEM. An ELISA-based method for rapid and convenient simulation of processing conditions for quantitative detection of antigen.

We developed an ELISA-based method for rapid optimization of various tissue processing parameters in immunogold labeling for electron microscopy. The effects of aldehyde fixation, tannic acid, postfixation, dehydration, temperature, and antigen retrieval on antibody binding activity of Vitreoscilla hemoglobin (VHb) expressed in E. coli cells were assayed by ELISA and the results confirmed by quantitative immunogold labeling transmission electron microscopy (TEM). Our results demonstrated that low concentrations (0.2%) of glutaraldehyde fixation caused minimal loss in total binding compared to higher concentrations. Dehydration in up to 70% ethanol resulted in some distortion of cellular ultrastructure but better antibody binding activity compared to dehydration up to 100%. Postfixation or incorporation of tannic acid in the primary fixative caused almost total loss of activity, whereas antigen retrieval of osmium-postfixed material resulted in approximately 90-100% recovery. The sensitivity of detection of proteins by immunogold labeling electron microscopy depends on the retention of antibody binding activity during tissue processing steps, e.g., fixation and dehydration. Our study indicated that an ELISA-based screening method of various tissue processing procedures could help in rapid selection and optimization of a suitable protocol for immunogold localization and quantification of antigen by TEM.     

Environmental enrichment committee: its role in program development

The authors discuss the role of the Environmental Enrichment Committee in developing, implementing, assessing, and modifying a university animal enrichment program.     

Group housing female guinea pigs

Group housing guinea pigs can save space and money, while improving housing standards. The authors describe enclosure design, enrichments, and husbandry techniques that facilitate group housing female guinea pigs.     

Lipid antioxidant, etoposide, inhibits phosphatidylserine externalization and macrophage clearance of apoptotic cells by preventing phosphatidylserine oxidation

Apoptosis is associated with the externalization of phosphatidylserine (PS) in the plasma membrane and subsequent recognition of PS by specific macrophage receptors. Selective oxidation of PS precedes its externalization/recognition and is essential for the PS-dependent engulfment of apoptotic cells. Because etoposide is a potent and selective lipid antioxidant that does not block thiol oxidation, we hypothesized that it may affect PS externalization/recognition without affecting other features of the apoptotic program. We demonstrate herein that etoposide induced apoptosis in HL-60 cells without the concomitant peroxidation of PS and other phospholipids. HL-60 cells also failed to externalize PS in response to etoposide treatment. In contrast, oxidant (H2O2)-induced apoptosis was accompanied by PS externalization and oxidation of different phospholipids, including PS. Etoposide potentiated H2O2-induced apoptosis but completely blocked H2O2-induced PS oxidation. Etoposide also inhibited PS externalization as well as phagocytosis of apoptotic cells by J774A.1 macrophages. Integration of exogenous PS or a mixture of PS with oxidized PS in etoposide-treated HL-60 cells reconstituted the recognition of these cells by macrophages. The current data demonstrate that lipid antioxidants, capable of preventing PS peroxidation, can block PS externalization and phagocytosis of apoptotic cells by macrophages and hence dissociate PS-dependent signaling from the final common pathway for apoptosis.