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Search Results: 1 - 10 of 340 matches for " bioassay "
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Calagem e o potencial de lixivia??o de imazaquin em colunas de solo
Inoue, M.H.;Marchiori Jr., O.;Oliveira Jr., R.S.;Constantin, J.;Tormena, C.A.;
Planta Daninha , 2002, DOI: 10.1590/S0100-83582002000100016
Abstract: two greenhouse experiments were carried out from march to december 1999, to evaluate the leaching potential of imazaquin in soil columns, after applying different levels of liming in samples of red latosol dystrophyc (lv) and dusky red latosol (lr). the experiments consisted basically in spraying imazaquin (150 g ha-1) on the top of columns filled with soils with different levels of liming, what caused them to be at different final ph values. after spraying, a simulated rainfall of 30 mm (lv) or 90 mm (lr) was applied to the top of the columns. three days later, cucumber (lv), lentil and sorghum (lr) seeds were distributed in a central furrow along the columns, and bioassays were performed to detect imazaquin leaching. the results showed that increasing liming levels resulted in a significantly higher leaching potential of imazaquin in soil columns. sorghum was more sensitive than lentil as a bioindicator of imazaquin activity.
Post-intervention assessment of long-lasting insecticide nets (LLINs) distributed in the Kano metropolis, Kano State, Nigeria  [PDF]
Gobir Zainab, Tukur Zainab
Advances in Entomology (AE) , 2013, DOI: 10.4236/ae.2013.12008
Abstract: Kano state has distributed about 4,137,464 Long Lasting Insecticide Nets (LLINs) in 2009 being one of the main malariavector control strategy developed by the Nigeria Federal Ministry of Health(FMOH) in line with Roll Back Malaria. The objective of the study was to evaluate the effectiveness of LLINs in use, the knowledge, attitude and practicesof some net users inthe Kano metropolis. A Cone bioassay with laboratory reared Anopheles was performed. Knock down after 60 minutes and mortality after 24 hours followed with a 3 minutes exposure were evaluated. A total of 210 households were administered with a structured questionnaire on two hundred and five (205) respondents (97.6%) indicated knowledge about LLINs while five (5) respondents (2.4%) were not aware. Very high and consistent knockdown and mortality in all 5 replicates were found. Respondent still holds some reservation on the use of LLINs, and one hundred and five respondents (54.8%) believed it causes heat. The respondents replied that they did not rely mostly on LLINs, despite their beliefs in the efficacy of it rather. 41.4% of the people that participated in the research still resorted to use of aerosols and 26.2% use smoke screens to prevent mosquito bites. It can be concluded from the findings that respondents were aware of long lasting insecticide net and agreed on its effectiveness against the vector of malaria parasite and other insects, with some having reservations on the use of smoke screens and indoor residual insecticide sprays to prevent mosquitobites. Considering that the nets are expected tobe effective for three years or more years, it is reasonable to conclude that the nets were effective in preventing mosquito bites based on the knock-down and exposure mortality results obtained during this study.

Evaluation of Insecticides Targeting Control of Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae)  [PDF]
Eliane Carneiro, Luciana Barboza Silva, Kellen Maggioni, Vilmar Buenos dos Santos, Thiago Ferreira Rodrigues, Soislan Souza Reis, Bruno Ettore Pavan
American Journal of Plant Sciences (AJPS) , 2014, DOI: 10.4236/ajps.2014.518298
Abstract:

Insecticides from different chemical groups were tested by laboratory bioassay to verify the percentage mortality of Helicoverpa armigera (Hubner 1808) (Lepidoptera: Noctuidae). The experiment was conducted in the Crop Science laboratory—Prof. CinobelinaElvas Campus—UFPI, Bom Jesus, PI, from January to June, 2013. The populations utilized came from the University’s own insect breeding laboratories. Third instar larvae of H. armigera were used to conduct the bioassay. The experimental design was fully randomized, with 13 treatments and four replications. Five larvae were used per replication, with 12 insecticides from 9 different chemical groups and a control. Each treatment consisted of three doses. The methods of application used were topical contact and ingestion in artificial diet. According to the results the percentage mortality of H. armigera larvae varied among the treatments. The results demonstrated that chlorpyrifos and spinosad were effective against third instar H. armigera larvae both on contact and by ingestion. Flubendiamide, acephate, methomyl, Bacillus thuringiensis, dimethoate, chlorantraniliprole and fipronil had good responses to control of H. armigera.

Nemacur Residue Analysis in Soil Water and Cucumber Samples Collected from the Field in Gaza Strip, Palestine  [PDF]
Mohammed Ouda Alloh, Said AL-Kurdi, M. R. Alagha, El-Nahhal Yasser
American Journal of Plant Sciences (AJPS) , 2018, DOI: 10.4236/ajps.2018.93039
Abstract: Application of Nemacur in Gaza strip increased rapidly as a potential alternative to the widely used soil sterilizing agent methyl bromide. Nemacur application may contaminate soil, water and plant systems due to its high solubility in water. The objective of this study was to determine Nemacur residues soil, water, and cucumber samples collected from a field plots applied Nemacur at different field rates (0.0, 0.5 F, 1 F, 2 F) where F is the recommended field rate of Nemacur (4 kg/Hectare). Nemacur residues were determined by chemo-assay and bioassay techniques. Results revealed that considerable Nemacur concentrations were found in cucumber fruits and plant leaves. Nemacur residues were higher in water samples collected from sandy soil (7.2 μg/L) than from clay soil (3.4 μg/L). Furthermore, Nemacur residues in sandy soil (0.23 μg/kg) were lower than those in clay soil (1.3 μg/kg). In addition, Nemacur
Development and Validation of a Microbiological Agar Assay for Determination of Orbifloxacin in Pharmaceutical Preparations
Edith C. L. Cazedey,Hérida R. N. Salgado
Pharmaceutics , 2011, DOI: 10.3390/pharmaceutics3030572
Abstract: Orbifloxacin is a fluoroquinolone with broad-spectrum antimicrobial activity, and belongs to the third generation of quinolones. Regarding the quality control of medicines, a validated microbiological assay for determination of orbifloxacin in pharmaceutical formulations has not as yet been reported. For this purpose, this paper reports the development and validation of a simple, sensitive, accurate and reproducible agar diffusion method to quantify orbifloxacin in tablet formulations. The assay is based on the inhibitory effect of orbifloxacin upon the strain of Staphylococcus aureus ATCC 25923 used as test microorganism. The results were treated statistically by analysis of variance and were found to be linear ( r = 0.9992) in the selected range of 16.0–64.0 μg/mL, precise with relative standard deviation (RSD) of repeatability intraday = 2.88%, intermediate precision RSD = 3.33%, and accurate (100.31%). The results demonstrated the validity of the proposed bioassay, which allows reliable orbifloxacin quantitation in pharmaceutical samples and therefore can be used as a useful alternative methodology for the routine quality control of this medicine.
Identifica??o de genes cry de Bacillus thuringiensis no controle de Sphenophorus levis, o bicudo da cana-de-a?úcar
Cícero, Elaine Aparecida Silva;Ferraudo, Antonio Sergio;Lemos, Manoel Victor Franco;
Bragantia , 2009, DOI: 10.1590/S0006-87052009000400001
Abstract: bacillus thuringiensis is well known for its ability to produce toxic proteins to different insect orders which are encoded by the cry genes. this work was carried out aiming to select among different b. thuringiensis isolates, by morphological and molecular characterization, identifying different classes of cry3 and cry35 genes, and to determine the level of pathogenicity against sphenophorus levis larvae, which is one of the most important sugar-cane pests in brazil. a total of 1163 bacterial isolates were used in this survey in which phase microscopy and molecular markers were used for evaluation that resulted in 30 isolates positive for cry3 and cry35 genes potentially active against coleopterans. these bacterial isolates together with type strains such as b. thuringiensis var. tenebrionis, b.t. var. morrissone e b.t. var. tolworthi were used in bioassays using sphenophorus levis larvae. using discriminating analysis four groups of isolates were produced when b. thuringiensis toxicity was taken into account. these groups involved one set of two isolates with up to 10% mortality; another set caused mortality of up to 39% and was made up of ten isolates and three type strains; another set caused mortality of up to 52% containing thirteen isolates and a last set of isolated whose mortality index was 70% containing only five isolates which were considered promising bacterial strains for biological control of s. levis.
In situ monitoring of mutagenicity of air pollutants in S?o Paulo City using Tradescantia-SHM bioassay
Ferreira, Maria Izildinha;Rodrigues, Geraldo Stachetti;Domingos, Marisa;Saldiva, Paulo Hilário do N.;
Brazilian Archives of Biology and Technology , 2003, DOI: 10.1590/S1516-89132003000200017
Abstract: the tradescantia stamen hair mutation assay (trad-shm) was employed for assessing the environmental mutagenesis in two areas of s?o paulo city. the study sites were defined as follows: 1) celso garcia avenue, an industrial area on the outskirts of the urban center (belém neighborhood), with an average daily traffic volume of 8,750 vehicles; 2) doutor arnaldo avenue, in downtown area (pinheiros neighborhood), with a mostly residential and business offices occupation, with an average daily traffic volume of 46,125 vehicles. the negative control (background) site is located in the city of jaguariúna, 138 km from s?o paulo, in an area of low atmospheric pollution. the mutation frequency observed for belém was similar to the background for clone 4430, whereas plants exposed in pinheiros showed significant increases in mutation rate. positive correlation was observed between mutation frequency and the levels of particulate matter in the atmosphere. this indicated a relationship between mutation frequency and the amount of atmospheric pollution present at the exposure sites in s?o paulo city, with special reference to vehicular emissions.
Toxic and Repellent effecto of Harmal (Peganum harmala L.) Acetonic Extract on Several Aphids and Tribolium castaneum (Herbst)
Salari,Elham; Ahmadi,Kamal; Dehyaghobi,Reza Zamani; Purhematy,Amin; Takalloozadeh,Haji Mohammad;
Chilean journal of agricultural research , 2012, DOI: 10.4067/S0718-58392012000100023
Abstract: to reduce the dependence on the sometimes unwise use of synthetic pesticides in fruit and vegetable plantations, the toxicity and repellence of peganum harmala l. (zygophyllaceae) acetonic seed extract was assayed against several insect pests. for contact toxicity, 3- to 4-d-old individuals of aphis fabae scopoli, a. gossypii glover, a. nerii boyer de fonscolombe, and myzus persicae (sulzer) were included, as well as 1- to 7-d-old adult tribolium castaneum (herbst). repellent effect experiments were conducted on adult, 1- to 2- and 3- to 4-d old m.persicae individuals. at 60 mg ml4, the topical bioassay mortality percentage was significantly higher in a. gossypii than in a. fabae and a. nerii after 12-72 h. mortality of the treatments on m.persicae was 87.1% and 90.0% after 24 and 48 h, respectively, and significantly higher than a. fabae and a. nerii during this period. at 60 mg ml-1, the mortality of t. castaneum was much lower than that of the aphid species. the highest repellent index (over 72%) was observed on 1- to 2-d-old m. persicae individuals.
Implementation of an in vitro bioassay as an indicator of the bionutrient FitoMas E
Díaz de Villegas,María Elena; Delgado,Grizel; Rivas,Mauricio; Torres,Esmérida; Saura,Maribel;
Ciencia e investigación agraria , 2011, DOI: 10.4067/S0718-16202011000200005
Abstract: seed bioassays are employed to determine the stimulatory effect of various biological products on the seed germination of plants used for the detection and control of toxic environmental contaminants. the objective of the present study was to design an in vitro bioassay to monitor the quality of the final production of fitomas e, a bionutrient derived from the sugar industry and produced by the instituto cubano de investigaciones de los derivados de la ca?a de azúcar by-products (icidca), by determining rates of seed germination and growth of lettuce (lactuca sativa l.) as an indicator plant. a significant effect of controllable factors under study (fitomas e concentration in lots and replicates of petri dishes) was determined by one-way and multifactor anova analysis. in all cases, the highest values of relative germination and growth occurred at a concentration of fitomas e of 0.1 ml l-1, with a marked increase in the growth of hypocotyl (rhg), which decreased at concentrations of 2.5 and 5 ml l-1. these results can be explained by the hormesis phenomenon, which is characterized by stimulation at low doses and inhibition at high doses. for a confidence level of p ≤ 0.05, there were no significant differences between petri dishes with lettuce seeds and lots in all responses tested. the bioassay method implemented in this study was fast, simple and reliable.
Persistência do herbicida Acetochlor em fun??o de sistemas de preparo e cobertura com palha
Ferri, Miguel Vicente Weiss;Vidal, Ribas Antonio;
Ciência Rural , 2003, DOI: 10.1590/S0103-84782003000300002
Abstract: the different soil management systems affects herbicide persistence and change the biological activity, crop selectivity and potencial to environmental risk. an experiment was carried out at the universidade federal do rio grande do sul, with the objective of evaluating the persistence of the acetochlor herbicide on tillage and conventional tillage systems with and without straw mulch on soil surface. the soil is classified as paleudult, and the herbicide dosis sprayed was 5040 g ha-1. the persistence of acetochlor herbicide was evaluated in a biossay, using wheat (triticum aestivun l.) as test plant. assessements included plant height. the acetochlor herbicide half-life was 29 and 30 day on straw mulch presence, and 18 e 16 days on straw mulch absence at the conventional tillage and no-tillage systems, respectively. straw mulch increased acetochlor herbicide persistence in the soil.
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