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The Protein Journal - β-Glucosidase is widely used in several industrial segments, among which we can highlight the pharmaceutical industry, beverages, biofuels, animal feed production, and...  相似文献   
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The survivorship of social insects is known to increase with group size, even in situations of stress, such as starvation and exposure to insecticides. However, in termites, studies have been undertaken only with workers, disregarding the possible effect of soldiers. The role of soldiers in the termite colonies goes beyond defense, mainly in Nasutitermes species. It is already known that soldiers initiate the foraging as well as improve the decision-making of food resources. Here, we evaluated the effect of group size and the presence of soldiers on exposure to sublethal doses of the insecticide imidacloprid in Nasutitermes corniger (Termitidae: Nasutitermitinae). To do so, toxicity bioassays were undertaken initially to determine the dose of the insecticide required to kill 50% of the N. corniger population (LD50) to be used in the main experiments. Survival bioassays were then carried out with termite groups, with and without soldiers, in different sizes (6, 10, 14, 22, 26, 30 and 60), exposed and nonexposed to insecticide. In general, the mean time to death of termites increases linearly with group size. However, the mean time to death in groups with soldiers was significantly longer only in groups exposed to the insecticide. Our results indicate that soldiers can help to increase the tolerance of nasute termite groups to insecticides, in addition to the group size, as already shown in the previous study. The size of the group and social context could, therefore, modulate behavioral and/or physiological responses that enhance the ability to survive under stressful situations.  相似文献   
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The present study focuses on trade-offs between the development rates and their life-history traits of feeding larvae. Indeed, quick growth is considered to be vital for necrophagous insects such as larvae because they are part of a rapidly changing ecosystem and at the mercy of many predators. However, excessively quick growth can have a negative effect on other life-history traits (e.g. survivorship and body size). The blowfly Lucilia sericata (Diptera: Calliphoridae) is used in the present study because this species is frequently found on carcasses in Central Europe and is a well-known experimental model in insect physiology and ecology. Individuals are reared from first instars to adults at two different constant temperatures (i.e. 15 and 28 °C) and under three different conditions: 100 Lucilia sericata (i.e. small monospecific condition), 250 L. sericata (i.e. large monospecific) or 125 L. sericata + 125 Calliphora vicina (i.e. heterospecific). The development time, pupal and larval survival rate and pupal size are determined individually under each condition. Regarding size and development time, substantial variation is observed between the different growth conditions and within a larval group under the same conditions. However, no trade-offs between development rate and size or survival are detected. These results demonstrate that, under the range of developmental conditions tested in the present study, the quick development of L. sericata larvae does not affect their size or mortality. This developmental plasticity may explain the evolutionary success of this species, which is present in several ecosystems worldwide and dominates the fresh-carrion ecosystem.  相似文献   
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Toxicity of tetracyclines was studied experimentally on different species of laboratory animals. It was shown that tetracycline, oxytetracycline and chlortetracycline were close by their chemical structure and physico-chemical properties, as well as by the main toxicity parameters, i.e. acute toxicity, cumulative activity, skin-irritating and sensitizing effect. Under the conditions of subacute experiments the above 3 antibiotics induced evenly pronounced one direction changes in animals. The data obtained during the experiments provided recommendation of the level of 0.1 mg/m3 as the maximum allowable concentration (MAC) of oxytetracycline and chlortetracycline, i.e. the same level as the previously recommended for tetracycline.  相似文献   
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Partitioning of 15 proteins in polyethylene glycol (PEG)–sodium sulfate aqueous two-phase systems (ATPS) formed by PEG of two different molecular weights, PEG-600 and PEG-8000 in the presence of different buffers at pH 7.4 was studied. The effect of two salt additives (NaCl and NaSCN) on the protein partition behavior was examined. The salt effects on protein partitioning were analyzed by using the Collander solvent regression relationship between the proteins partition coefficients in ATPS with and without salt additives. The results obtained show that the concentration of buffer as well as the presence and concentration of salt additives affects the protein partition behavior. Analysis of ATPS in terms of the differences between the relative hydrophobicity and electrostatic properties of the phases does not explain the protein partition behavior. The differences between protein partitioning in PEG-600–salt and PEG-8000–salt ATPS cannot be explained by the protein size or polymer excluded volume effect. It is suggested that the protein–ion and protein–solvent interactions in the phases of ATPS are primarily important for protein partitioning.  相似文献   
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