Lepidopteran insects mainly rely on sex pheromones to complete sexual communications. Pheromone receptors (PRs) are expressed on the olfactory receptor neurons (ORNs) of the sensilla trichodea and play an essential role in sexual communication. Despite extensive investigations into the mechanisms of peripheral recognition of sex pheromones in Lepidoptera, knowledge about these mechanisms in remains limited.
View Article and Find Full Text PDFMicroRNAs (miRNAs) regulate various biological processes in insects. However, their roles in the regulation of insect diapause remain unknown. In this study, we address the biological function of a conserved miRNA, let-7-5p in the regulation of a juvenile hormone primary response gene, Krüppel homolog 1 (Kr-h1), which modulates reproductive diapause in Galeruca daurica.
View Article and Find Full Text PDFThe plant bug Lygus pratensis Linnaeus (Hemiptera: Miridae) is an important insect pest of alfalfa in grassland farming in northern China. A field population of L. pratensis was selected in the laboratory for 14 consecutive generations with lambda-cyhalothrin to generate 42.
View Article and Find Full Text PDFCitrus Huanglongbing (HLB) is one of severe quarantine diseases affecting citrus pro-duction both in abroad and domestic. Based on the mechanism and characteristics of citrus HLB transmission, we establish a vector-borne model with stage structure and integrated strategy and inves-tigate the effect of the strategy in controlling the spread of HLB. By calculating, we obtain the basic reproductive number R, and prove that the disease can be eradicated if R < 1, whereas the disease will persist if R > 1.
View Article and Find Full Text PDFBackground: Motivated by the first mathematical model for schistosomiasis proposed by Macdonald and Barbour's classical schistosomiasis model tracking the dynamics of infected human population and infected snail hosts in a community, in our previous study, we incorporated seasonal fluctuations into Barbour's model, but ignored the effect of bovine reservoir host in the transmission of schistosomiasis. Inspired by the findings from our previous work, the model was further improved by integrating two definitive hosts (human and bovine) and seasonal fluctuations, so as to understand the transmission dynamics of schistosomiasis japonica and evaluate the ongoing control measures in Liaonan village, Xingzi County, Jiangxi Province.
Methods: The basic reproductive ratio R and its computation formulae were derived by using the operator theory in functional analysis and the monodromy matrix theory.
Background: Schistosomiasis japonica, caused by infection with Schistosoma japonicum, is still recognized as a major public health problem in the Peoples' Republic of China. Mathematical modelling of schistosomiasis transmission has been undertaken in order to assess and project the effects of various control strategies for elimination of the disease. Seasonal fluctuations in transmission may have the potential to impact on the population dynamics of schistosomiasis, yet no model of S.
View Article and Find Full Text PDFBackground: The transmission of schistosomiasis japonica in a local setting is still poorly understood in the lake regions of the People's Republic of China (P. R. China), and its transmission patterns are closely related to human, social and economic factors.
View Article and Find Full Text PDFFen Zi Xi Bao Sheng Wu Xue Bao
August 2007
To investigate the cell differentiation and the expression profiles of PPARy and C/EBPalpha mRNA, the rat preadipocytes were cultured after dispersed by enzymolysis of collagenase type I and the cell shape were observed under the microscope. The MTT method was adopted to determine the growth curve. The expression levels of PPARgamma and C/EBPalpha mRNA were also detected by relative quantitative RT-PCR.
View Article and Find Full Text PDFIn order to investigate the development of Kunming mouse preimplantation embryos cultured in vitro under simulated microgravtiy, one-cell and 4-cell embryos of Kunming mouse (Fertilization In Situ) were cultured in CZB or KSOM media under simulated microgravity or normal gravity environment respectively. The results showed that under normal gravity, the percentage of passing 2-cell development block embryos was not different in CZB with in KSOM, but the percentage of blastocysts was lower in CZB than that in KSOM significantly. The percentages of passing 2-cell development block embryos and blastocysts in CZB or KSOM were lower under simulated microgravity than those under normal gravity.
View Article and Find Full Text PDFShi Yan Sheng Wu Xue Bao
February 2004
In order to investigate the biocompatibility, degradation and inflammatory reactions of poly benzyl glutamate (PBLG), poly lactic-co-glycolic acid (PLGA) and fibrin gel used as the scaffolds co-cultured with the hepatocytes of rats under simulated microgravity conditions in rotating wall vessel bioreactor (RWVB). PLGA is low biocompatibility, PBLG is medium biocompatibility with rat hepatocytes. Fibrin gel is high biocompatibility, no toxic degradation and no inflammatory reactions.
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