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Open access

X. Cheng, Y. Jiang, T. Tang, G. Fan and Xiaoxia Huang

Abstract

Altitude is thought to have greatly influenced current species distribution and their genetic diversity. However, it is unclear how different altitudes have affected the distribution and genetic diversity of Picea likiangensis, a dominant forestry species in the Qinghai-Tibetan Plateau region (QTP). In this study, we investigated the genetic diversity of Picea likiangensis populations which distributed in different altitudes of QTP using EST-SSR markers. The results suggested that this species has high genetic diversity at species level, with 100% of loci being polymorphic and an average Nei’s gene diversity (He) of 0.7186 and Shannon’s information index (I) of 1.5415. While the genetic diversity of Picea likiangensis at population level was lower than that at species level, with He and I being 0.6562 and 1.3742, respectively. The variation in genetic diversity of all four studied populations indicated a low-high-low pattern along the elevation gradients. The mid-elevation population (3050 m) was more genetically diverse than both low-elevation (2900 m) and high-elevation populations (3200 m and 3350 m). Nei’s genetic diversity (Fst = 0.0809) and AMOVA analysis (Phist = 0.1135) indicated that a low level of genetic differentiation among populations. Gene flow among populations was 2.8384, suggesting that high gene flow is a main factor leading to high levels of the genetic diversity among populations.

Open access

Guang-Hou Zhou, Li Han, Zhen-Nan Fan, Yong Liao and Song Huang

Abstract

To study the principle of loss and heat at the end region of large 4-poles nuclear power turbine generator, 3D transient electromagnetic field and 3D steady temperature field finite element (FE) models of the end region are established respectively. Considering the factors such as rotor motion, core non-linearity and time-varying of electromagnetic field, the anisotropic heat conductivity and different heat dissipation conditions of stator end region, a 50 Hz, 1150 MW, 4-poles nuclear power turbine generator is investigated. The loss and heat at the generator end region are calculated respectively at no-load and rated-load, and the calculation results are compared with the test data. The result shows that the calculation model is accurate and the generator design is suitable. The method is valuable for the research of loss and heat at the end region of large 4-poles nuclear power turbine generator and the improvement of the generator’s operation stability. The method has been applied successfully for the design of the larger nuclear power turbine generators

Open access

Fan Lin, Jianbin Xiahou and Qihua Huang

Abstract

In replication management under multi-datacenter cloud storage environments, the problem of a replica being inconsistent across multiple datacenters must be solved. Focusing on data management strategies under multiple datacenters, this paper presents a design of a HDFS-based two Cascading Master-Slave Storage System (2CMSSS), which simplifies the research work of the replication management strategies under multi-datacenter cloud storage environments. On this basis a two-phase locking maintenance strategy for replica consistency is presented to validate and fix the problem of replica inconsistency across multiple datacenters. According to the experiment simulation, this strategy can ensure strong data consistency and maintain low latency for users to access data.

Open access

Bo Zhou, Xiaoyuan Huang, Pengfei Liang, Licheng Ren, Bimei Jiang, Pengju Fan, Xuhuang, Chunhua Liao and Chenchen Zuo

Abstract

Background: Mild heat stress provides protection to cells, which is known as thermal tolerance. Various kinds of heat shock proteins have been proven to play important roles in this process. Another antiapoptotic factor induced by mild heat stress, peroxisome proliferator activated receptor beta (PPAR-β), provides a protective effect to cells against subsequent oxidant injury.

Objective: To understand the expression of PPAR-β and other proteins in human umbilical vein endothelial cells (HUVECs) during mild heat stress. H2O2-induced apoptosis of cells with mild heat pretreatment were also investigated to elucidate cell resistance to oxidant injury.

Methods: HUVECs were chosen in the current study because vascular endothelial cells in burn wounds, especially in the zone of stasis, suffer sequentially from heat stimulus and oxidant injury.

Results: The cells were subjected to 43 ☐C for 25 minutes and allowed to recover for different times (from 1 to 72 hours). The PPAR-β expression was found to be upregulated in the later recovery stage. BCL-2 also showed a similar trend, but P53 showed otherwise. Heat pretreated HUVECs were exposed to 400 μmol/L of H2O2 for 12 hours, and apoptosis rate was assessed. H2O2-induced apoptosis was attenuated by heat pretreatment and by the PPAR-β agonist GW0742 (p < 0.01 and p < 0.05 versus control group); HUVECs transfected with PPAR-β shRNA seemed much more susceptible to oxidation damage (p < 0.05 versus the control group). Mild heat stress also upregulated the BCL-2 expression relative to PPAR-β.

Conclusion: Heat-induced PPAR-β may be partly responsible for this process, which may also be one of the possible explanations of the antiapoptotic function of PPAR-β, although the specific mechanism needs further examination.

Open access

Jianhui Jin, Yunming Huang, Zhizhong Li, Xuechun Fan, Zhiyong Ling, Zhixing Li and Xiaoju Liu

Abstract

The possible role of environmental change, especially sea level change, as a stimulus for the development of human residence and migration is poorly understood. We investigate this problem by showing a record of sea-level change and coastal transformation based on a sediment core (FN1 core) and a Neolithic site (Pingfengshan site) obtained from the Funing bay on the northeast coast of Fujian, China. The Funing bay coastal area represents a unique feature in China’s Neolithic cultures, comprising a silty beach dominated by quartz-rich sand and several important sites of Huangguashan cultural period.

Samples from FN1 core and Pingfengshan site were taken for grain size ananlyses and for optically stimulated luminescence (OSL) dating. The blue-light stimulated OSL signals were measured by the single aliquot regenerative dose (SAR) protocol to determine the ages of of the samples. Samples from FN1 core yield OSL ages ranging from 49.9 ka to 0.8 ka, providing the systematic geochronological evidence for the sea level change of Funing bay. The comparison of sea level change and Neolithic cultural periods presents a good relationship in coastal area of Fujian, China since about 7 ka before present. In detail, the cultural types of Keqiutou culture and Huangguashan culture all belong to coastal mountainous culture, of which flourishing periods corresponds to the higher sea level periods of mid-late Holocene. Tanshishan culture belongs to estuarine coastal culture, and most sites of this period correspond to a lower sea level located at lower altitudes.

Open access

Walter King Yan Ho, Md Dilsad Ahmed, Chi Ian Leong, Patrick Chan, Rudolph Leon Van Niekerk, Fan Huang, Haili Tian, Min Liu, Nikon Chan, João Silva, Wilfred Wong, Frederick K. Ho and Patrick Ip

Abstract

There is evidence that rapid weight gain during the first year of life is associated with being overweight later in life. Therefore, overweight tendencies need to be detected at an appropriate age, and suitable strategies need to be implemented for weight management to achieve optimal long-term health. The objective of this study was to investigate comparisons in BMI status and associated categories in male and female students over ten years in two phases, including 2008-2013 and 2009-2014. Weight and height data were collected to obtain BMI (Body Mass Index) over ten years in two phases. The first phase occurred from 2008 to 2013, and the second phase occurred from 2009 to 2014 in a population of 10846 school children (Males: 6970, 64.3%, and females: 3875, 35.7%) in Macau. Their ages ranged from 6 years old in 2008 to 11 years old in 2013. The same age range was observed in the second phase, i.e., 2009-2014. Statistical analyses included descriptive statistics, such as the mean, standard deviation, t-tests to determine gender differences (year-wise) and a Chi square test for independence to determine the relationship between BMI (Underweight, Standard, Overweight and Obese) and age groups. In the first phase (2008-2013), the findings indicated a higher BMI level among the male students than the female students across all age groups (2008 t = 5.24, 2009 t = 88.25, 2010 t = 11.32, 2011 t = 17.45, 2012 t = 19.70 and 2013 t = 19.92). In the second phase (2009-2014), a higher BMI level was found among the male students than the female students across all age groups (2009 t = 2.68, 2010 t = 2.886, 2011 t = 3.076, 2013 t = 4.228, and 2014 t = 2.405). The results of the two phases combined (2008 to 2014 and 2009 to 2014) revealed that male students in 2008 had a higher BMI level than their counterparts in 2009 in the two age categories (8 years t = 3.025 and 11 years t = 3.377). Female students in the second phase (2009-2014) showed a higher BMI level than their male counterparts (9 years, t = 3.151). The results indicate the need to have focused strategies and structured interventions for male students at the critical age range of 8 to 9 years old. The results of this study also imply the need for the delivery of suitable school intervention activities at the appropriate time. Specifically, the prevention of weight gain should start early in life to encourage the development of healthier behaviours and habits throughout childhood and later ages.