Association of the Pro12Ala, C161-T polymorphisms in the PPARγ2 gene with obesity in Han nationality of Yunnan Plateau in Southwest China

Background Obesity is considered a major public health problem in the world. At present, the association of single nucleotide polymorphisms (SNPS) Pro12Ala and C161-T in peroxisome proliferator-activated receptor gamma 2 (PPARγ2) gene with obesity is still controversial. The aim of this study is to evaluate the relationship between the Pro12Ala and C161-T polymorphisms of PPARγ2 gene and obesity among Han nationality of Yunnan Plateau in Southwest China. Methods The genotypes of 284 extremely overweight patients, 475 obese patients and 759 normal controls from Yongsheng County of Yunnan Province (China) were analyzed. The Pro12Ala and C161-T genotypes of PPARγ2 were detected by SNaPshot genotyping assay. The data were analyzed statistically. Results The overall prevalence of obesity was 4.99% and the overweight rate was 23.93% among Han nationality in Yongsheng, Yunnan Province. Statistical analysis showed that there were no significant differences in the Pro12Ala genotype, C161-T genotype and the two combined genotypes between the extremely overweight and the control 1, either between the obesity and the control 2 (P > 0.05). Further, the alleles of Pro12Ala and C161-T did not exhibit any signifificant association with extreme overweight or obesity among the complete sample population (P > 0.05). However, conditional logistic regression analysis showed that there was a statistically significant association between the two combined genotype of “CC + TT” and the extreme overweight after adjusting for covariates (Calculated with the combined genotype of “CC + CC ” as the reference category; P = 0.014; OR = 4.04; 95%CI = 1.33–12.33). Conclusions Our study indicates that the combined genotypes "CC + TT" of PPARγ2 Pro12Ala and C161-T were associated with an increased risk of extreme overweight, however, Pro12Ala and C161-T polymorphisms may not be the main cause of obesity in Han nationality of the Yunnan Plateau in Southwest China.

Distribution and altitudinal patterns of carbon and nitrogen storage in various forest ecosystems in the central Yunnan Plateau, China

The carbon (C) pool in forest ecosystems plays a long-term and sustained role in mitigating the impacts of global warming, and the sequestration of C is closely linked to the nitrogen (N) cycle. Accurate estimates C and N storage (SC, SN) of forest can improve our understanding of C and N cycles and help develop sustainable forest management policies in the content of climate change. In this study, the SC and SN of various forest ecosystems dominated respectively by Castanopsis carlesii and Lithocarpus mairei (EB), Pinus yunnanensis (PY), Pinus armandii (PA), Keteleeria evelyniana (KE), and Quercus semecarpifolia (QS) in the central Yunnan Plateau of China, were estimated on the basis of a field inventory to determine the distribution and altitudinal patterns of SC and SN among various forest ecosystems. The results showed that (1) the forest SC ranged from 179.58 ± 20.57 t hm−1 in QS to 365.89 ± 35.03 t hm−1 in EB. Soil, living biomass and litter contributed an average of 64.73%, 31.72% and 2.86% to forest SC, respectively; (2) the forest SN ranged from 4.47 ± 0.94 t ha−1 in PY to 8.91 ± 1.83 t ha−1 in PA. Soil, plants and litter contributed an average of 86.88%, 10.27% and 2.85% to forest SN, respectively; (3) the forest SC and SN decreased apparently with increasing altitude. The result demonstrates that changes in forest types can strongly affect the forest SC and SN. This study provides baseline information for forestland managers regarding forest resource utilization and C management.

Attenuation of ultraviolet radiation and photosynthetically active radiation in six Yunnan Plateau lakes of China based on seasonal field investigations

Solar radiation is a primary driver affecting several physical, chemical and biological processes in lake ecosystems. The attenuation of sunlight in water is directly controlled by optically active substances. Here, the seasonal and interlake heterogeneities of the diffuse attenuation coefficients (Kd(λ)) of ultraviolet radiation (UVR) and photosynthetically active radiation (PAR) were studied based on field investigations in six Yunnan Plateau lakes (i.e., Chenghai, Dianchi, Erhai, Fuxian, Lugu and Yangzong) of China, October 2014‒July 2016. The results revealed that Kd(λ) generally increased with decreasing wavelength and increasing trophic state and that Kd(UVR) presented higher interlake heterogeneity than Kd(PAR). The interlake heterogeneity surpassed the seasonal heterogeneity of Kd(λ), whereas the intralake seasonal heterogeneity, which is related to the lake trophic state and solar spectrum, was obvious. Although the main factors affecting Kd(λ) were chromophoric dissolved organic matter (CDOM) and phytoplankton in general, the interlake heterogeneity was found. In eutrophic, turbid shallow Lake Dianchi, CDOM primarily affected UV-B, whereas total suspended solids (TSS) and/or phytoplankton had important effects on Kd(UV-B), Kd(UV-A) and Kd(PAR). CDOM, TSS and phytoplankton influenced the Kd(UV-B), Kd(UV-A) and Kd(PAR) in the deep mesotrophic Lake Chenghai and Lake Erhai, but the main particulate factors were different between these two lakes. In the deep, oligotrophic clear Lake Fuxian and Lake Lugu, only the significant effect of CDOM on Kd(UVR) in Lake Fuxian was detected. Additionally, the factors affecting Kd(λ) in Lake Yangzong were atypical, possibly due to the artificial addition of massive amounts of ferric chloride.