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Quantifying inter-specific variations of tree resilience to drought and revealing the underlying mechanisms are of great importance to the understanding of forest functionality, particularly in water-limited regions. So far, comprehensive studies incorporating investigations in inter-specific variations of long-term growth patterns of trees and the underlying physiological mechanisms are very limited. Here, in a semi-arid site of northern China, tree radial growth rate, inter-annual tree-ring growth responses to climate variability, as well as physiological characteristics pertinent to xylem hydraulics, carbon assimilation and drought tolerance were analyzed in seven pine species growing in a common environment. Considerable inter-specific variations in radial growth rate, growth response to drought and physiological characteristics were observed among the studied species. Differently, the studied species exhibited similar degrees of resistance to drought-induced branch xylem embolism, with water potential corresponding to 50% loss hydraulic conductivity ranging from −2.31 to −2.96 MPa. We found that higher branch hydraulic efficiency is related to greater leaf photosynthetic capacity, smaller hydraulic safety margin and lower woody density (P  < 0.05, linear regressions), but not related to higher tree radial growth rate (P  > 0.05). Rather, species with higher hydraulic conductivity and photosynthetic capacity were more sensitive to drought stress and tended to show weaker growth resistance to extreme drought events as quantified by tree-ring analyses, which is at least partially due to a trade-off between hydraulic efficiency and safety across species. This study thus demonstrates the importance of drought resilience rather than instantaneous water and carbon flux capacity in determining tree growth in water-limited environments. [ABSTRACT FROM AUTHOR]

Aims Cunninghamia lanceolata is one of the most important coniferous species in southern China, but its high sensitivity to drought restricts its expansion. Understanding the intraspecific variation of physiological responses to drought can help us manage this plantation better. Methods We selected 3-year-old seedlings of C. lanceolata , which originated from the low precipitation (LP), middle precipitation (MP) and high precipitation (HP) habitats, respectively. Seedlings were grown under drought stress (20% of soil volumetric water content) for 40 days. The ecophysiological responses and adaptive strategies with different drought tolerance were investigated. Important Findings LP provenance possessed the best tolerance to drought stress, suggesting that considerably increased carbohydrates and nitrogen-containing compounds as osmotic protective materials, which were driven by fast carbon and nitrogen metabolisms. In addition, the highest peroxidase activity could effectively eliminate hydrogen peroxide in drought-stressed LP provenance. The MP provenance reserved a large amount of non-structural carbohydrates, which may act as a certain buffer for encountering drought stress. Importantly, timely closure of stomata to reduce needle transpiration when encountering a water deficiency would help them adapt to long-term drought. MP provenance adopted a conservative water-saving strategy. However, HP provenance regulated root growth (increased root/shoot ratio) and reduced penetration potential to help them absorb water. The different strategies among provenances may be related to the long-term domestication of the geographical environments. Therefore, our results underline the importance of provenance-specific responses to drought stress. It is highly significant to accelerate the selection of drought-resistant germplasms and to cultivate high-yield plantations in the future. [ABSTRACT FROM AUTHOR]

During their lifetimes, plants are exposed to different abiotic stress factors eliciting various physiological responses and triggering important defense processes. For UV-B radiation responses in forest trees, the genetics and molecular regulation remain to be elucidated. Here, we exposed Pinus tabuliformis Carr. a major conifer from northern China, to short-term high-intensity UV-B and employed a systems biology approach to characterize the early physiological processes and the hierarchical gene regulation, which revealed a temporal transition from primary to secondary metabolism, the buildup of enhanced antioxidant capacity and stress-signaling activation. Our findings showed that photosynthesis and biosynthesis of photosynthetic pigments were inhibited, while flavonoids and their related derivates biosynthesis, as well as glutathione and glutathione S-transferase mediated antioxidant processes, were enhanced. Likewise, stress-related phytohormones (jasmonic acid, salicylic acid and ethylene), kinase and reactive oxygen species signal transduction pathways were activated. Biological processes regulated by auxin and karrikin were, for the first time, found to be involved in plant defense against UV-B by promoting the biosynthesis of flavonoids and the improvement of antioxidant capacity in our research system. Our work evaluated the physiological and transcriptome perturbations in a conifer's response to UV-B, and generally, highlighted the necessity of a systems biology approach in addressing plant stress biology. [ABSTRACT FROM AUTHOR]

Background Impairment in facial emotion perception is an important domain of social cognition deficits in schizophrenia. Although impaired facial emotion perception has been found in individuals with negative schizotypy (NS), little is known about the corresponding change in brain functional connectivity. Methods Sixty-four participants were classified into a high NS group (n = 34) and a low NS group (n = 30) based on their total scores on the Chapman scales for physical and social anhedonia. All participants undertook a facial emotion discrimination functional imaging task that consisted of four emotional valences (angry, fear, happy, and neutral). For univariate analysis, the signal change at the bilateral amygdala was compared for each emotional contrast using SPSS (P <.05). For the functional connectivity analysis, we calculated the beta-series functional connectivity of the bilateral amygdala with the medial prefrontal cortex (mPFC) and compared the group differences in SPM12 (P <.05, small volume family-wise error correction). Results No significant differences were found between the high and low NS groups in accuracy and reaction time in the facial emotion discrimination task. The high NS group showed reduced brain activations at the amygdala under fearful and neutral conditions. Reduced functional connectivity between the amygdala and the mPFC/dorsal anterior cingulate cortex under the happy and fearful conditions in the high NS group was also found. Conclusions Our findings suggest that the individuals with high NS showed altered brain activity and functional connectivity at the amygdala during facial emotion processing and provide new evidence for understanding social cognition deficits in at-risk individuals. [ABSTRACT FROM AUTHOR]

Temperature responses and sensitivity of photosynthesis (An_T) and respiration for leaves at different ages are crucial to modeling ecosystem carbon (C) cycles and productivity of evergreen forests. Understanding the mechanisms and processes of temperature sensitivity may further shed lights on temperature acclimation of photosynthesis and respiration with leaf aging. The current study examined temperature responses of photosynthesis and respiration of young leaves (YLs) (fully expanded in current growth season) and old leaves (OLs) (fully expanded in last growth season) of Quercus aquifolioides Rehder and E.H. Wilson in an alpine oak forest, southwestern China. Temperature responses of dark respiration (Rdark), net assimilation (An), maximal velocity of carboxylation (Vcmax) and maximum rate of electron transport (Jmax) were significantly different between the two leaf ages. Those differences implied different temperature response parameters should be used for leaves of different ages in modeling vegetation productivity and ecosystem C cycles in Q. aquifolioides forests and other evergreen forests. We found that RuBP carboxylation determined the downward shift of An_T in OLs, while RuBP regeneration and the balance between Rubisco carboxylation and RuBP regeneration made little contribution. Sensitivity of stomatal conductance to vapor pressure deficit changed in OLs and compensated part of the downward shift. We also found that OLs of Q. aquifolioides had lower An due to lower stomatal conductance, higher stomatal conductance limitation and deactivation of the biochemical processes. In addition, the balance between Rdark and An changed between OLs and YLs, which was represented by a higher Rdark/An ratio for OLs. [ABSTRACT FROM AUTHOR]

Objective. CD200/CD200R1 signalling has an immunoregulatory effect on the activation threshold of the inflammatory immune response and maintains immune homeostasis. In this study we evaluated the status of CD200/CD200R1 interaction in patients with RA. Methods. The expression of CD200 and CD200R1 was examined by immunohistochemistry and flow cytometry and was compared between RA patients and healthy controls (HCs). Sorted CD4+ T cells were stained with carboxyfluorescein succinimidyl ester (CFSE) and annexin V-propidium iodide to evaluate the effect of CD200 on cell proliferation and apoptosis. The effect of CD200 on Th17 differentiation, function and osteoclastogenesis was determined by flow cytometry, transwell migration assay and immunocytochemistry, respectively. Results. The proportion of CD200+ cells and CD200R1+ cells in peripheral blood mononuclear cells, peripheral CD14+ cells and CD4+ T cells was significantly lower in the RA patients than in HCs, whereas the number of CD200+ cells was higher in synovium from RA patients than in that from HCs. After treatment with infliximab and MTX we found increased expression of peripheral CD200/CD200R1 that correlated with a decrease in the 28-joint DAS. CD200Fc in vitro partially inhibited CD4+ T cell proliferation, promoted CD4+ T cell apoptosis, reduced CD4+ T cell differentiation into Th17 cells and down-regulated CCR6-mediated Th17 chemotaxis in cells from RA patients. In addition, the engagement of the CD200 receptors on CD14+ cells with CD200Fc in vitro reduced osteoclastogenesis and inhibited CD14+ celldriven Th17 differentiation. Conclusion. Abnormal CD200/CD200R1 expression in RA may contribute to abnormal Th17 cell differentiation, chemotaxis and osteoclastogenesis. [ABSTRACT FROM AUTHOR]

Objectives. We aimed to investigate whether CD147 can up-regulate the chemotactic, adhesive and invasive properties of human neutrophils and to determine the mechanism underlying this process.Methods. Human promyelocytic leukaemia cells (HL-60) cells and peripheral blood or synovial fluid neutrophils were isolated from RA patients. Under cyclophilin A (CypA) stimulation, chemotaxis, adhesion potential and invasion ability were assessed using chemotaxis, adhesion and invasiveness assays. Lipid raft isolation and western blot were used to determine the mechanism underlying the effects of CypA stimulation.Results. CD147 up-regulates the calcium-induced chemotaxis, adhesion ability and invasiveness of human neutrophils in RA patients. Transient receptor potential melastatin 7 may be responsible for this phenomenon.Conclusion. These findings suggest that in RA patients, abundant CypA up-regulates the calcium-induced chemotactic, adhesive and invasive properties of neutrophils via direct binding to CD147. Cyclophilin–CD147 interactions might contribute to the destruction of cartilage and bone in RA. [ABSTRACT FROM PUBLISHER]

Men and women at Northwest University (n=751), Xi'an, China were asked to judge the attractiveness of photographs of female patients who had undergone micrograft surgery to reduce their waist-to-hip ratios (WHR). Micrograft surgery involves harvesting adipose tissue from the waist and reshaping the buttocks to produce a low WHR and an 'hourglass' female figure. This gynoid distribution of female body fat has been shown to correlate with measures of fertility and health. Significantly larger numbers of subjects, of both sexes, chose post-operative photographs, with lower WHRs, as more attractive than pre-operative photographs of the same women. Some patients had gained, and some had lost weight, post-operatively, with resultant changes in body mass index (BMI). However, these changes in BMI were not related to judgments of attractiveness. These results show that the hourglass female figure is rated as attractive in China, and that WHR, rather than BMI, plays a crucial role in such attractiveness judgments [Current Zoology 56 (2): 175-181, 2010]. [ABSTRACT FROM AUTHOR]

The maize inbred lines Huangzao 4 (HZ4) and Chang 7-2 (C7-2) are the foundation genotypes key to maize cross-breeding in China. C7-2 is derived from HZ-4. In this study, changes in phenotype, physiology and gene expression of three-leaf-old seedlings of HZ4 and C7-2 under the conditions of progressive water deficit (WD) and re-watering (RW) were compared to gain knowledge for breeding new maize foundation genotypes with higher drought tolerance. Progressive WD was produced by adding polyethylene glycol (PEG 6000) at 24 h intervals (24, 48 and 72 h) in Hoagland’s nutrient solution, resulting in water potentials of −0.15, −0.3 and −0.5 MPa. The seedlings treated for 24 h at −0.3 MPa were subjected to RW in the solution without complementation with PEG. The results showed that C7-2 seedlings are more tolerant to progressive WD than HZ4 seedlings in part because the former have a larger stomatal resistance, a relatively stronger leaf water-holding capacity, and a timely and stable increase in activities of antioxidant enzymes (superoxide dismutase and peroxidase) especially in roots upon WD. Oligonucleotide probe array-based analysis uncovered a number of WD- and RW-regulated genes in both inbred lines, and clearly indicated that fine transcriptional coordination between maize leaves and roots is one of the factors constituting higher WD tolerance and a greater ability for growth recovery from WD. On the basis of the resulting data and co-regulation of responsive genes in tissues, we propose a model for the whole maize plant tolerance to growth and recovery from WD. [ABSTRACT FROM PUBLISHER]

The metabolic consequences of obesity are well-documented in Western populations. However, limited data are available on the association between body mass index (BMI) and cardiovascular risk factors in developing countries. The authors therefore examined the association between BMI and cardiovascular risk factors in a very lean population in China. A total of 2,542 subjects aged 20–70 years from a rural area of Anqing, China, participated in a cross-sectional survey, and 1,610 provided blood samples in 1993. Mean BMI (kg/m2) was 20.7 for men and 20.9 for women. After adjustment for age, sex, education level, occupation, current alcohol use, and cigarette smoking, BMI was significantly associated with systolic and diastolic blood pressures (p < 0.0001). The adjusted odds ratio for hypertension (systolic pressure ≥140 mmHg or diastolic pressure ≥ 90 mmHg) across quintiles of BMI (quintife medians: 18.0, 19.4, 20.6, 21.8, and 24.0) were 1.0, 1.34, 2.46, 2.61, and 4.90 (95%confidence interval: 3.20, 7.50). A higher BMI was directly associated with higher levels of serum total cholesterol, triglycerides, and fasting glucose and lower levels of high density lipoprotein cholesterol. These data from a very lean Chinese population confirm independent relations between body mass and cardiovascular risk factors observed in predominantly overweight Western populations and extend the range of associations to lower BMI levels than do previous studies. Am J Epidemiol 20OQ; 151:88–97. [ABSTRACT FROM PUBLISHER]

The diel cycle in the percentage abundance of parthenogenetic females carrying embryos of different developmental stages in the marine cladocerans Penilia avirostris, Pseudevadne tergestina, Pleopis polyphymoides and Pleopis schmackeri was studied at the edge of an artificial rocky shore area in a semi-enclosed bay in Hong Kong. Females carried embryos during both day and night, but females with fully-developed embryos were found predominantly at night. The diel cycle in the abundance of females with mature embryos was most pronounced in P. tergestina, and less prominent, but still clearly noticeable in P. avirostris, P. schmackeri and P. polyphymoides. The absence or scarcity of females with mature embryos during daytime could be caused by both selective predation by visual predators and nocturnal maturation and release of embryos. Juveniles of Acanthopagrus schlegeli (black seabream) were the most abundant planktivorous fish in the study area in spring. Stomach content analyses revealed that these daytime predators fed intensively on marine cladocerans and exhibited a strong selection for females with mature embryos. On the other hand, the gradual decline in the percentage of females with advanced embryos during the latter part of the night, when feeding by visual predators presumably had not yet begun, suggests that there was a tendency for nocturnal release of neonates in marine cladocerans. [ABSTRACT FROM AUTHOR]

Background: Cancer screening with highly sensitive, specific biomarkers that reflect molecular phenotypic alterations is an attractive strategy for cancer control. We examined whether biomarker profiles could be used for risk assessment and cancer detection in a cohort of Chinese workers occupationally exposed to benzidine and at risk for bladder cancer.Methods: The cohort consisted of 1788 exposed and 373 nonexposed workers, followed from 1991 through 1997. We assayed urothelial cells from voided urine samples for DNA ploidy (expressed as the 5C-exceeding rate [DNA 5CER]), the bladder tumor-associated antigen p300, and a cytoskeletal protein (G-actin). Workers were stratified into different risk groups (high, moderate, and low risk) at each examination based on a predefined biomarker profile. For workers who developed bladder cancer, tumor risk assessment was analyzed from samples collected 6-12 months before the cancer diagnosis. The associations between risk group and subsequent development of bladder cancer were analyzed by Cox proportional hazards regression analysis and logistic analysis, after adjustment. All statistical tests were two-sided.Results: Twenty-eight bladder cancers were diagnosed in exposed workers and two in nonexposed workers. For risk assessment, DNA 5CER had 87.5% sensitivity, 86.5% specificity, an odds ratio (OR) of 46.2 (95% confidence interval [CI] = 8.1 to 867.0), and a risk ratio (RR) of 16.2 (95% CI = 7.1 to 37.0); p300 had 50.0% sensitivity, 97.9% specificity, an OR of 40.0 (95% CI = 9.0 to 177.8), and an RR of 37.9 (95% CI = 16.8 to 85.3). The risk of developing bladder cancer was 19.6 (95% CI = 8.0 to 47.9) times higher in workers positive for either the DNA 5CER or p300 biomarkers than in workers negative for both biomarkers and 81.4 (95% CI = 33.3 to 199.3) times higher in workers positive for both biomarkers. G-actin was a poor marker of individual risk.Conclusions: Occupationally exposed workers at risk for bladder cancer can be individually stratified, screened, monitored, and diagnosed based on predefined molecular biomarker profiles. [ABSTRACT FROM AUTHOR]

A response from the authors of the article "Association of leukocyte telomere length with breast cancer risk: nested casecontrol findings from the Shanghai Women's Health Study" in a 2013 issue of the journal is presented.

The authors investigated whether polymorphisms in two maternal metabolic genes, cytochrome P-450 1A1 (CYP1A1) MspI and epoxide hydrolase 1 (EPHX1) Tyr113His, affect the association of maternal passive smoking with infant birth weight. The study was conducted in a cohort of 1,388 newly married mothers of liveborn singletons who worked in textile mills in Anqing, China, from 1996 to 2000. Multiple linear regression models were used to estimate the associations of passive smoking and genetic susceptibility with birth weight, with adjustment for important potential confounders. In the passive smoking group, there was a remarkable decrease in birth weight with the C/C6235 genotype (156.3 g, 95% confidence interval (CI): −283.6, −29.0) for CYP1A1 MspI and with Tyr/His113 (93.8 g, 95% CI: −188.6, −1.1) as compared with His/His113 (244.6 g, 95% CI: −491.0, −1.9) for EPHX1. When results were stratified by maternal genotype, passive smoking conferred a significantly negative effect in the EPHX1 Tyr/His113 group (103.5 g, 95% CI: −205.8, −9.2) and in the His/His113 group (687.3 g, 95% CI: −748.3, −178.3). The data further showed that there was a significant interaction between maternal passive smoking and maternal EPHX1 genotype for birth weight. The authors conclude that the CYP1A1 MspI and EPHX1 genotypes modified the association between maternal passive smoking and infant birth weight in this study, which is suggestive of possible gene-environment interaction. [ABSTRACT FROM AUTHOR]