In this paper,based on the structure-behavior coupling paradigm,we propose the concept of deviation of central town to describe the geography-market distance between farmers and the central regional town.Using the sur...In this paper,based on the structure-behavior coupling paradigm,we propose the concept of deviation of central town to describe the geography-market distance between farmers and the central regional town.Using the survey data from farmers in a poverty-stricken village in Western China,the impact of deviation of central town on farmers'livelihood strategies is analyzed.The results indicate that farmers exhibit spatial heterogeneity in their livelihood strategies.Those with low deviation show a strong inclination towards working in urban areas,while those with high deviation tend to integrate into rural industries.The deviation of central town influences farmers'livelihood strategies through the information effect,which is also affected by the level of rural infrastructure and public services,labor force structure and assistance policies.The obtained results are expected to provide guidance for promoting the integration of farmers into the urban-rural economic cycle based on sustainable livelihoods and connecting poverty alleviation with rural revitalization.展开更多
The effect of obesity on idiopathic central precocious puberty（ICPP） girls is still under discussion. The relationship between body mass index（BMI） and sexual hormone levels of gonadotropin-releasing hormone（GnRH...The effect of obesity on idiopathic central precocious puberty（ICPP） girls is still under discussion. The relationship between body mass index（BMI） and sexual hormone levels of gonadotropin-releasing hormone（GnRH） stimulation test in ICPP girls is controversial and the underlying mechanism is unclear. This study aims to further explore the independent effect of excess adiposity on peak luteinizing hormone（LH） level of stimulation test in ICPP girls and the role of other related factors. A retrospective cross-sectional study was performed on 618 girls diagnosed as having ICPP, including 355 cases of normal weight, 99 cases of overweight and 164 cases of obese. The results showed that obese group had more progressed Tanner stage and no significant difference（P=0.28） in LH peak was found as basal LH value was used as a covariate. The obese group had higher total testosterone（TT）, adrenocorticotrophic hormone（ACTH）, 17-α hydroxyprogesterone（17-αOHP） and androstendione（AN）, with significantly increased fasting insulin（FIN） and homeostasis model of assessment for insulin resistance index（HOMA-IR）. Stratified analysis showed inconsistency of the relationship between BMI-standard deviation score（BMI-SDS） and LH peak in different Tanner stages（P for interaction=0.017）. Further smoothing plot showed linear and non-linear relationship between BMI-SDS and LH peak in three Tanner stages. Then linear regression model was used to analyze the relationship between BMI-SDS and LH peak in different Tanner stages, with and without different confounding factors being adjusted. In B2 stage, BMI-SDS was negatively associated with LH peak. In B3 stage, when BMI-SDS 〈1.5, as BMI-SDS increased, the level of LH peak decreased（model Ⅰ： β=–1.8, 95% CI=–4.7 to 1.1, P=0.214）. When BMI-SDS ≥1.5, BMI-SDS was significantly positively associated with LH peak（model Ⅰ： β=4.5, 95% CI=1.7 to 7.4, P=0.002）. In B4 stage, when BMI-SDS 〈1.5, BMI-SDS was negatively associated with LH peak（model Ⅰ： β=–11.6, 95% CI=–22.7 to –0.5, P=0.049）. When BMI-SDS ≥1.5, BMI-SDS was positively associated with LH peak（model Ⅰ： β=–4.2, 95% CI=–3.3 to 11.7, P=0.28）. It is concluded that there is an independent correlation between BMI-SDS and LH peak of stimulation test in ICPP girls, their relationships are different in different Tanner stages, and the effect of BMI-SDS can be affected by adrenal androgens, estradiol and glucose metabolism parameters.展开更多
We consider a branching random walk on N with a random environment in time （denoted by ξ）. Let Zn be the counting measure of particles of generation n, and let Zn（t） be its Laplace transform. We show the converge...We consider a branching random walk on N with a random environment in time （denoted by ξ）. Let Zn be the counting measure of particles of generation n, and let Zn（t） be its Laplace transform. We show the convergence of the free energy n-llog Zn（t）, large deviation principles, and central limit theorems for the sequence of measures {Zn}, and a necessary and sufficient condition for the existence of moments of the limit of the martingale Zn（t）/E[Zn（t）ξ].展开更多
文摘In this paper,based on the structure-behavior coupling paradigm,we propose the concept of deviation of central town to describe the geography-market distance between farmers and the central regional town.Using the survey data from farmers in a poverty-stricken village in Western China,the impact of deviation of central town on farmers'livelihood strategies is analyzed.The results indicate that farmers exhibit spatial heterogeneity in their livelihood strategies.Those with low deviation show a strong inclination towards working in urban areas,while those with high deviation tend to integrate into rural industries.The deviation of central town influences farmers'livelihood strategies through the information effect,which is also affected by the level of rural infrastructure and public services,labor force structure and assistance policies.The obtained results are expected to provide guidance for promoting the integration of farmers into the urban-rural economic cycle based on sustainable livelihoods and connecting poverty alleviation with rural revitalization.
基金supported by grants from 12th five-year Plan National Key Technology R&D Program(No.2012BAI09B04)Program for Changjiang Scholars and Innovative Research Team in University(No.PCSIRT1131)
文摘The effect of obesity on idiopathic central precocious puberty（ICPP） girls is still under discussion. The relationship between body mass index（BMI） and sexual hormone levels of gonadotropin-releasing hormone（GnRH） stimulation test in ICPP girls is controversial and the underlying mechanism is unclear. This study aims to further explore the independent effect of excess adiposity on peak luteinizing hormone（LH） level of stimulation test in ICPP girls and the role of other related factors. A retrospective cross-sectional study was performed on 618 girls diagnosed as having ICPP, including 355 cases of normal weight, 99 cases of overweight and 164 cases of obese. The results showed that obese group had more progressed Tanner stage and no significant difference（P=0.28） in LH peak was found as basal LH value was used as a covariate. The obese group had higher total testosterone（TT）, adrenocorticotrophic hormone（ACTH）, 17-α hydroxyprogesterone（17-αOHP） and androstendione（AN）, with significantly increased fasting insulin（FIN） and homeostasis model of assessment for insulin resistance index（HOMA-IR）. Stratified analysis showed inconsistency of the relationship between BMI-standard deviation score（BMI-SDS） and LH peak in different Tanner stages（P for interaction=0.017）. Further smoothing plot showed linear and non-linear relationship between BMI-SDS and LH peak in three Tanner stages. Then linear regression model was used to analyze the relationship between BMI-SDS and LH peak in different Tanner stages, with and without different confounding factors being adjusted. In B2 stage, BMI-SDS was negatively associated with LH peak. In B3 stage, when BMI-SDS 〈1.5, as BMI-SDS increased, the level of LH peak decreased（model Ⅰ： β=–1.8, 95% CI=–4.7 to 1.1, P=0.214）. When BMI-SDS ≥1.5, BMI-SDS was significantly positively associated with LH peak（model Ⅰ： β=4.5, 95% CI=1.7 to 7.4, P=0.002）. In B4 stage, when BMI-SDS 〈1.5, BMI-SDS was negatively associated with LH peak（model Ⅰ： β=–11.6, 95% CI=–22.7 to –0.5, P=0.049）. When BMI-SDS ≥1.5, BMI-SDS was positively associated with LH peak（model Ⅰ： β=–4.2, 95% CI=–3.3 to 11.7, P=0.28）. It is concluded that there is an independent correlation between BMI-SDS and LH peak of stimulation test in ICPP girls, their relationships are different in different Tanner stages, and the effect of BMI-SDS can be affected by adrenal androgens, estradiol and glucose metabolism parameters.
基金Acknowledgements The authors would like to thank the anonymous referees for valuable comments and remarks. This work was partially supported by the Natural Scientific Research Innovation Foundation in Harbin Institute of Technology （HIT. NSRIF. 2015102）, the National Natural Science Foundation of China （Grant Nos. 11171044, 11101039）, and by the Natural Science Foundation of Hunan Province （Grant No. 11JJ2001）.
文摘We consider a branching random walk on N with a random environment in time （denoted by ξ）. Let Zn be the counting measure of particles of generation n, and let Zn（t） be its Laplace transform. We show the convergence of the free energy n-llog Zn（t）, large deviation principles, and central limit theorems for the sequence of measures {Zn}, and a necessary and sufficient condition for the existence of moments of the limit of the martingale Zn（t）/E[Zn（t）ξ].
