7,862 research outputs found
Comparative efficacy of microbial and chemical insecticides on four major lepidopterous pests of cotton and their (insect) natural enemies
Three microbial (biotrol, dipel and thuricide) and three chemical insecticides (monocrotophos, endosulfan and carbaryl) were compared for efficacy on four major lepidopterans and their natural enemies in replicated field trials at Moor Plantation, Ibadan. Thuricide was evaluated at different combinations with monocrotophos in a second trial. The results showed that the microbials caused the mortalities of destructive bollworms and leafroller but allowed the survival of their natural enemies. The chemicals on the other hand caused mortalities of both destructive and useful species. Both groups of insecticides enhanced seed cotton yields. Application of thuricide followed by monocrotophos was better than other combinations evaluated.
Key words: microbial insecticides, Bacillus thuringiensis, cotton.
African Journal of Biotechnology Vol.2(11) 2003: 425-42
The Effects of using Pictures on EFL Learnersâ Vocabulary Retention
Innovation is necessary for improvement. This inspirational saying triggered the author to try new things for enhancement. This study explored the effect of using pictures to instruct vocabulary in EFL classrooms. At the same time, the EFL studentsâ attitudes toward this instruction were also examined. To have the data for the study, a group of 70 seventh-graders at Duyen Hai Ethnic Boarding Junior High School in Tra Vinh province were recruited as participants. The study had two parts. The first part of the study dealt with the intervention of vocabulary instruction in the two groups of students. 35 students were chosen for the experimental group, and the other 35 for the control group. The experimental group was exposed to vocabulary instruction with pictures while the control group was taught with the traditional vocabulary teaching method (without using pictures). Both groups had undergone the pretest, posttest, and delayed tests. The results showed that both groupsâ scores on vocabulary tests improved, but the experimental groupâs scores were higher than that of its counterparts. Then, the study also had the result of the experimental studentsâ attitudes toward the intervention of using pictures to teach vocabulary. They had a positive attitude toward this teaching strategy. Finally, based on the results of the study, some suggestions and limitations of the study were proposed
Antidiabetic effect of Tibetan medicine Tang-Kang-Fu-San on high-fat diet and streptozotocin-induced type 2 diabetic rats
The aim of this study was to investigate the antidiabetic effects of a Tibetan medicine, Tang-Kang-Fu-San (TKFS), on experimental type 2 diabetes mellitus (T2DM) rats and to explore its underlying mechanisms. Firstly two major chemical compositions of TKFS, gallic acid and curcumin, were characterized by HPLC fingerprint analysis. Next T2DM in rats was induced by high-fat diet and a low-dose streptozotocin (STZ 35âmg/kg). Then oral gavage administration of three different doses of TKFS (0.3âg/kg, 0.6âg/kg, and 1.2âg/kg) was given to T2DM rats. Experimental results showed that TKFS dramatically reduced the levels of fasting blood glucose, fasting blood insulin, triglyceride, total cholesterol, LDL cholesterol, and HDL cholesterol, even though it did not alter the animal body weight. The downregulation of phosphorylation-AKT (p-AKT) and glucose transporter-4 (GLUT4) in skeletal muscle of T2DM rats was restored and abnormal pathological changes in pancreas tissues were also improved. Our work showed that TKFS could alleviate diabetic syndromes, maintain the glucose homeostasis, and protect against insulin resistance in T2DM rats, and the improvement of AKT phosphorylation and GLUT4 translocation in skeletal muscle would be one of its possible underlying mechanisms
Distribution et incidence de la mosaĂŻque du concombre (cmv) dans des bananeraies industrielles au sud-est de la cĂŽte dâivoire.
La distribution et lâincidence du virus de la mosaĂŻque du concombre (CMV) infectant le bananier ont Ă©tĂ© Ă©valuĂ©es dans les bananeraies au Sud-Est de la CĂŽte dâIvoire. Pour ce faire, des prospections ont Ă©tĂ© effectuĂ©es dans des plantations industrielles des secteurs de NiĂ©ky (Dabou); BanacomoĂ© (Abengourou) et Grand-fleuve (TiassalĂ©). Des donnĂ©es de relevĂ©s phytosanitaires relatives au CMV ont Ă©tĂ© recueillies et des Ă©chantillons de feuilles symptomatiques et asymptomatiques de bananiers de la variĂ©tĂ© ââGrande naineââ ont Ă©tĂ© collectĂ©s. Des diagnostics sĂ©rologiques utilisant les tests DAS-ELISA (Double Antibody Sandwich Enzyme Linked Immunosorbent Assay), ont permis de confirmer la prĂ©sence du CMV dans ces Ă©chantillons. Dans la pĂ©piniĂšre du secteur BanacomoĂ©, le CMV a Ă©tĂ© diagnostiquĂ© dans environ 50 % de lots de plantules issus de micropropagation (vitroplants). Lâincidence de la maladie enregistrĂ©e sur la base des symptĂŽmes observĂ©s dans les trois secteurs indiquent un taux variant de 5 % Ă 25 % avec une prĂ©dominance (66,25 %) des symptĂŽmes sĂ©vĂšres (pourriture du coeur) sur les plants de 3 mois dâĂąges. Cependant, les plantations de plus de trois mois dâĂąge et les plants de la collection in vivo de pieds mĂšres utilisĂ©s pour la micropropagation nâont prĂ©sentĂ© que de rares plants infectĂ©s. La rĂ©partition du CMV dans les plantations de moins de 3 mois a rĂ©vĂ©lĂ© une prĂ©dominance des foyers dâinfection de type marginal.Mots clĂ©s : Cucumber Mosaic Virus, DAS-ELISA, incidence, distribution, Musa spp., CĂŽte dâIvoireThis survey has been carried out in order to study the incidence and distribution of the Cucumber Mosaic Virus (CMV) infecting banana in the South-East part of CĂŽte dâIvoire. For this purpose, an assessment was conducted in the zones of NiĂ©ky (Dabou); BanacomoĂ© (Abengourou) and Grand-fleuve (TiassalĂ©), in order to gather phytosanitary data concerning the occurrence of the CMV in the nursery and fields. Banana leaf samples of the ââGrande naineââvariety showing CMV symptoms and some without symptom were collected. The presence of the virus has been confirmed by serological tests using DAS-ELISA (Double Antibody Sandwich Enzyme Linked Immunosorbent Assay). About 50 % of the tissue culture derived banana batches composing the nursery in a plantation of Abengourou was found to be infected by CMV. Based on symptoms observed, the incidence of the disease in these production sectors visited, varied from 5 % to 25 % with a predominance (66,25 %) of severe symptoms (heart-rot, symptoms) on plants of less than 3 month of age. However, plants beyond three months showed less CMV infected plants and less severe symptoms. Similarly, only few plants were infected in the germplasm containing mother plants used for micropropagation. In the field, banana plants showing CMV symptoms were more frequently distributed at the edge of the fields
Gastro-protective effect of Crossopteryx febrifuga in Wistar rats
Preparations of Crossopteryx febrifuga (Afzel.) Benth. (Rubiaceae) are widely used in Northern Nigeria in the therapeutic management of trypanosomiasis, malaria and painful inflammatory disorders. Previous studies have shown that the methanolic stem bark extract of Crossopteryx febrifuga possesses significant analgesic and anti-inflammatory properties possibly mediated via Non-selective inhibition of cyclo-oxygenase pathways. In the present study, the methanolic stem bark extract of Crossopteryx febrifuga was evaluated against ethanol- and piroxicam-induced ulceration in rats. Histopathological studies of the rat stomach tissues were also carried out in order to determine its safety profile on the gastrointestinal tract (git). The extract (25, 50 and100 mg extract/kg body weight) significantly (
Modeling of Ni Diffusion Induced Austenite Formation in Ferritic Stainless Steel Interconnects
Ferritic stainless steel interconnect plates are widely used in planar solid oxide fuel cell (SOFC) or electrolysis cell (SOEC) stacks. During stack production and operation, nickel from the Ni/YSZ fuel electrode or from the Ni contact component diffuses into the IC plate, causing transformation of the ferritic phase into an austenitic phase in the interface region. This is accompanied with changes in volume and in mechanical and corrosion properties of the IC plates. In this work, kinetic modeling of the inter-diffusion between Ni and FeCr based ferritic stainless steel was conducted, using the CALPHAD approach with the DICTRA software. The kinetics of inter-diffusion and austenite formation was explored in full detail, as functions of layer thickness, temperature, time, and steel composition. The simulation was further validated by comparing with experimental results. Growth of the austenite phase in commercial interconnect materials is predicted to take place under practical stack operation conditions.</jats:p
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