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Systematically investigating the impacts of Pleistocene sea-level fluctuations on mangrove plants may provide a better understanding of their demographic history and useful information for their conservation. Therefore, we conducted population genomic analyses of 88 nuclear genes to explore the population dynamics of a mangrove tree Lumnitzera racemosa across the Indo-West Pacific region. Our results revealed pronounced genetic differentiation in this species between the populations from the Indian Ocean and the Pacific Ocean, which may be attributable to the long-term isolation between the western and eastern coasts of the Malay Peninsula during sea-level drops in the Pleistocene glacial periods. The mixing of haplotypes from the two highly divergent groups was identified in a Cambodian population at almost all 88 nuclear genes, suggesting genetic admixture of the two lineages at the boundary region. Similar genetic admixture was also found in other populations from Southeast Asia based on the Bayesian clustering analysis of six nuclear genes, which suggests extensive and recent secondary contact of the two divergent lineages in Southeast Asia. Computer simulations indicated substantial migration from the Indian Ocean towards the South China Sea, which likely results in the genetic admixture in Southeast Asia.

Aerobic fitness is considered to be an important marker of current health and even a predictor of future health. The aim of this study was to systematically analyse the available scientific information on temporal changes in maximal long-distance running performance (a widely and long-used marker of aerobic fitness) of Asian children. A systematic review of the scientific literature was undertaken to locate studies explicitly reporting on temporal changes (spanning a minimum of 5 years) in maximal long-distance running of apparently healthy (free from known disease or injury) Asian children aged 9-17 years. Studies were located up to October 2010 via computerized searching of bibliographical databases, reference list searching and personal communication with international experts. Temporal changes were analysed at the country by sex by age by test level using best-fitting linear or polynomial regression models relating the year of testing to long-distance running performances expressed as average running speeds. Changes in means were expressed as percent changes and as standardized effect sizes. Eight studies reporting temporal changes in the long-distance running performance of 23,897,571 children aged 9-17 years from four Asian countries over the period 1964-2009 were included. Overall, there was a large decline in long-distance running performance equivalent to -16.6 ± 1.3% (mean change ± 95% confidence interval) or -1.2 ± 0.1 standard deviations. Temporal changes were generally consistent for different sex and age groups, but not for different countries, with large declines observed for children from China and the Republic of Korea, small declines for children from Japan and very small declines for children from Singapore. There is overwhelming evidence of meaningful declines in the maximal long-distance running performance of Asian children in recent decades, which are probably caused by a network of social, behavioural, physical, psychosocial and physiological factors. These declines highlight the need for regular surveillance of Asian children's health-related fitness and proactive public health strategies.

Nonalcoholic fatty liver disease (NAFLD) is a major risk factor for type 2 diabetes and metabolic syndrome. However, accurately differentiating nonalcoholic steatohepatitis (NASH) from hepatosteatosis remains a clinical challenge. We identified a critical transition stage (termed pre-NASH) during the progression from hepatosteatosis to NASH in a mouse model of high fat-induced NAFLD, using lipidomics and a mathematical model termed dynamic network biomarkers (DNB). Different from the conventional biomarker approach based on the abundance of molecular expressions, the DNB model exploits collective fluctuations and correlations of different metabolites at a network level. We found that the correlations between the blood and liver lipid species drastically decreased after the transition from steatosis to NASH, which may account for the current difficulty in differentiating NASH from steatosis based on blood lipids. Furthermore, most DNB members in the blood circulation, especially for triacylglycerol (TAG), are also identified in the liver during the disease progression, suggesting a potential clinical application of DNB to diagnose NASH based on blood lipids. We further identified metabolic pathways responsible for this transition. Our study suggests that the transition from steatosis to NASH is not smooth and the existence of pre-NASH may be partially responsible for the current clinical limitations to diagnose NASH. If validated in humans, our study will open a new avenue to reliably diagnose pre-NASH and achieve early intervention of NAFLD.

Enhanced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity in the monocytes occurred in metabolic syndrome, hypertension, diabetes and obese patients in adults. However, whether NADPH oxidase is involved in the oxidative stress of overweight adolescents without comorbidities is still unclear. This study aimed to identify whether and how NADPH oxidase plays a crucial role in overweight adolescents. The study was performed in 93 overweight adolescents and 31 normal weight controls. Moreover, 87 overweight adolescents were enrolled in weight‐loss program. Demographics characteristics, anthropometrics, composition and clinical characteristics were analyzed. Oxidative stress indexes including the levels of superoxide dismutase (SOD) and malondialdehyde (MDA) in plasma and the expression of NADPH oxidase in the monocytes were examined. Overweight adolescents showed a higher oxidative stress state, as indicated by decreased SOD activity and elevated MDA level (P < 0.01). Furthermore, increased NADPH oxidase activity in the monocytes was accompanied by Rac1 upregulation. A significant positive bivariate correlation was found between Rac1 expression and MDA (r = 0.289). There also was a significant positive bivariate correlation between Rac1 expression and obesity‐related indexes including BMI (r = 0.227) and percentage of trunk fat (r = 0.233). Data from weight‐loss program reinforced the results. Partial correlation analysis indicated that obesity‐induced oxidative stress and Rac1 expression is a consequence of aberrant glucose‐lipid metabolism in overweight adolescents. In conclusion, we provided novel data showing that NADPH oxidase in the monocytes was highly activated by enhancing Rac1 expression in Chinese overweight adolescents and Rac1 may act as a link between obesity and oxidative stress in overweight adolescents.

Article impact statement: Genomic information can help prevent species loss, facilitate reserve design and maximize adaptive potential of natural mangrove populations.

This study aimed to investigate the characteristics of insulin resistance and β-cell secretion in healthy adolescents. A total of 124 adolescents with normal glucose tolerance (NGT) were divided according to BMI into normal weight (n=31; control), overweight (n=52) and obese (n=41) groups. Oral glucose tolerance tests were performed, and blood glucose (G0, G30 and G120) and insulin (I0, I30 and I120) levels at 0, 30 and 120 min, respectively, were measured. The homeostasis model assessment estimate of insulin resistance (HOMA-IR) and early insulin release index (IRI) were calculated to evaluate insulin sensitivity and early β-cell secretion. The G0, G120 levels and the natural logarithm (Ln) of I30 and ΔI30/ΔG30 were similar in the overweight and obese groups, but significantly higher compared with those of the normal weight group (P<0.05). LnI0 and LnHOMA-IR progressively increased (P<0.01) in correlation with the degree of obesity among the three groups. LnΔI30/ΔG30 and LnHOMA-IR were significantly positively correlated with the indices of obesity (P<0.001 and P<0.05, respectively). LnHOMA-IR was also positively correlated with the insulin levels at 30 and 120 min (r=0.454 and 0.314, respectively; P<0.001). In healthy adolescents, insulin resistance progressively increased with increased body mass index (BMI), but the compensatory increase in early insulin secretion was limited.

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