AIM： TO estimate the prevalence of the lactase non-persistent genotype （C/C-23910） in a northern Russian population in accordance with ethnicity, and to evaluate self-reported milk consumption depending on lactase ...AIM： TO estimate the prevalence of the lactase non-persistent genotype （C/C-23910） in a northern Russian population in accordance with ethnicity, and to evaluate self-reported milk consumption depending on lactase activity. METHODS： Blood samples for genotyping lactase activity, defining the C/T-13910 variant by polymerase chain reaction, and direct sequencing were taken from 231 medical students of Russian origin aged 17-26 years. We analyzed milk product consumption by questionnaire which was specially designed for the estimation of milk consumption and abdominal complaints. RESULTS： We found that the prevalence of the C/C-13190 genotype in the northern Russian population was 35.6%. The other genotypes nearby C/T-13910 and associated with lactase activity were not present in the study population. The consumption of milk among people with the non-persistent genotype tended to be lower than among the lactose tolerant subjects, but was not statistically significant. CONCLUSION： An investigation of the lactase persistent genotype in a northern Russian population has not been performed before, The genotype did not affect the consumption of milk products in this population which could be explained by low consumption of milk products among the entire study population.展开更多
The author considers a three-species ratio-dependent predator-prey model with time delay in a two-patch environments. This model is of periodic coefficients, which incorporates the periodicity of the environment. By m...The author considers a three-species ratio-dependent predator-prey model with time delay in a two-patch environments. This model is of periodic coefficients, which incorporates the periodicity of the environment. By means of the coincidence degree theory, sufficient conditions for the existence of at least one positive periodic solution of this model are established. Moreover, The author shows that the system is uniformly persistent under the conditions.展开更多
In the real world, quite a few infectious diseases like schistosomiasis spread seasonally. In this paper, a nonautonomous schistosomiasis system is established, in which the saturation incidence rate and the coefficie...In the real world, quite a few infectious diseases like schistosomiasis spread seasonally. In this paper, a nonautonomous schistosomiasis system is established, in which the saturation incidence rate and the coefficients varying with time are taken into account. The long-time behavior of the model is studied. Under quite weak assumptions, sufficient conditions for the permanence and extinction of infectious population of disease are obtained. Finally, numerical simulations illustrate the validity of our results.展开更多
基金The Sigrid Jusélius Foundation,Helsinki,Finland and Tampere University Hospital Research Funds
文摘AIM： TO estimate the prevalence of the lactase non-persistent genotype （C/C-23910） in a northern Russian population in accordance with ethnicity, and to evaluate self-reported milk consumption depending on lactase activity. METHODS： Blood samples for genotyping lactase activity, defining the C/T-13910 variant by polymerase chain reaction, and direct sequencing were taken from 231 medical students of Russian origin aged 17-26 years. We analyzed milk product consumption by questionnaire which was specially designed for the estimation of milk consumption and abdominal complaints. RESULTS： We found that the prevalence of the C/C-13190 genotype in the northern Russian population was 35.6%. The other genotypes nearby C/T-13910 and associated with lactase activity were not present in the study population. The consumption of milk among people with the non-persistent genotype tended to be lower than among the lactose tolerant subjects, but was not statistically significant. CONCLUSION： An investigation of the lactase persistent genotype in a northern Russian population has not been performed before, The genotype did not affect the consumption of milk products in this population which could be explained by low consumption of milk products among the entire study population.
基金The research is supported by the Scientific Research Foundation of the Doctor Department of Hubei University of Technology.
文摘The author considers a three-species ratio-dependent predator-prey model with time delay in a two-patch environments. This model is of periodic coefficients, which incorporates the periodicity of the environment. By means of the coincidence degree theory, sufficient conditions for the existence of at least one positive periodic solution of this model are established. Moreover, The author shows that the system is uniformly persistent under the conditions.
基金Special thanks to the anonymous referees who have given us very useful suggestions. The research has been supported by the Natural Science Foundation of China （11261004）, the National Key Technologies R＆D Program of China （2009BAI78B01） and the Science and Technology Plan Projects of Jiangxi Provincial Education Department （GJJ14665, GJJ14673）.
文摘In the real world, quite a few infectious diseases like schistosomiasis spread seasonally. In this paper, a nonautonomous schistosomiasis system is established, in which the saturation incidence rate and the coefficients varying with time are taken into account. The long-time behavior of the model is studied. Under quite weak assumptions, sufficient conditions for the permanence and extinction of infectious population of disease are obtained. Finally, numerical simulations illustrate the validity of our results.
