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Showing 4 results for Kavousi


Volume 3, Issue 4 (12-2014)
Abstract

The toxicity of thiamethoxam and pirimicarb on Diaeretiella rapae (Mc'Intosh) as a parasitoid of Lipaphis erysimi (Kaltenbach), exposed to residues on glass vials, was investigated under laboratory conditions at 23 ± 2 °C, 70 ± 5% RH and 16:8 h (L: D). Moreover, in order to find the negative impacts of both insecticides on the efficiency of D. rapae, the functional response of the exposed parasitoids were assessed. The newly emerged parasitoids were exposed to LC25 of the insecticides and distilled water as control. Host densities of 2, 4, 6, 8, 16, 32 and 64 were placed on canola seedlings in a transparent cylindrical container and were offered to the treated parasitoids. Type of functional response was determined by means of logistic regression method and the parameters, attack rate (a) and handling time (Th) were calculated by nonlinear regression model using SAS software. The parasitoid exhibited type II functional response in all experiments. Attack rates in control, pirimicarb and thiamethoxam were 0.057 ± 0.01,0.059 ± 0.013 and 0.040 ± 0.01 h-1, and handling times were 1.097 ± 0.1, 1.86 ± 0.02, 2.81 ± 0.296 h, respectively. Maximum rates of parasitism (T/Th) were estimated 21.87, 12.9, 8.53 aphids, respectively. These observations suggest that pirimicarb with less harmful effects is the preferred candidate for controlling the mustard aphid.
K. Kavousi, A. R. Hamidi Zahedani,
Volume 10, Issue 3 (Summer 2019)
Abstract

The large biological networks increase computational complexity during the execution of the algorithm and create constraints for working with such networks. By preserving the behavior and output of the main network, complexity is reduced, and the process of obtaining results and analyzing the network is quickly accomplished. Using mathematical and computational tools to simplify the biology networks provides better results in various sciences, especially in applications of biological sciences. Boolean modelling and finding adsorbents in biological networks will make it easy to display and analyze. This study was carried out through Boolean modelling on the Abscise Acid signal transduction network. Abscise Acid is one of the most important and effective regulators in plant growth. Our method started from an initial state and according to the rules of updating, found network adsorbents. Our proposed method, in contrast to other methods, will be able to simultaneously detect the absorbing points while plotting the state transition graph. In this way, finding all the system adsorbents is guaranteed.

Shohreh Ariaeenejad, Morteza Maleki, Safura Nooshi Nedamani, Kaveh Kavousi, Ghasem Hosseini Salekdeh,
Volume 12, Issue 2 (1-2022)
Abstract

Enzymes play an essential role in catalyzing the reactions for multiple industrial applications. One of these critical industries with a worldwide application is paper and pulp, which is cost-effective in increasing attention. Xylanases are potential enzymes that proved their abilities in a broad range of applications, specifically in the paper and pulp industry as a biobleaching agent and dye removal biocatalyst. In these decades, the production of novel enzymes from natural sources is conceivable, especially with applying the culture-independent method of metagenome. This practical approach provides the opportunity to identify the novel enzymes from uncultivable microbial diversities. Concerning the importance of the thermostable enzymes for industrial applications and their better action in harsh conditions, this study aimed to identify novel thermostable xylanase from metagenomic data of sheep rumen by applying the in-silico screening. The thermostable xylanase was extracted from the ruminal DNA and after cloning and expression named PersiXyn5. The enzymeschr('39') kinetic parameters, including Km, Vmax, and its specific activity, were examined. The enzyme was optimally active at 80  and pH 8 and could retain 58% of its maximum activity after 2h of incubation at 90 . The thermostable, alkali PersiXyn5 was an efficient enzyme in the paper industry and poultry feed and fuel applications.

Volume 16, Issue 89 (7-2019)
Abstract

Studying the microbiota of food materials is important from sanitary, spoilage and technological perspectives. Due to manual harvesting, grading and packaging of date fruit (Phoenix dactylifera L.), it's not surprising to find bacteria of human origin in date fruit products. On the other hand, microbes present in date palm, especially high moisture content fruits, could produce lactic acid and acetic acid and make the fruit sour, so this kind of microbes potentially could be useful especially in food fermentation and vinegar production. In this project, seven varieties of date fruits were examined chemically and microbiologically. Total solid and acidity of dates were between 72% to 86% and 0.06% to 0.78% respectively. Isolated bacteria were identified by 16S rDNA amplification and restriction analysis (ARDRA), sequencing and 16S rRNA gene comparison. The results show Staphylococcus epidermidis, Aerococcus, Bacillus and Leuconostoc mesenteroides are the present bacteria in local date fruits.

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