Characteristics of multi-temporal scale variation of vegetation coverage in the Circum Bohai Bay Region, 1999–2009

Long-term spatial–temporal dynamics of vegetation coverage is a key problem of issues include global climate change study, regional ecological process monitoring and ecosystem management. Based on SPOT-VGT 10-day composite data over the Circum Bohai Bay Region from 1999 to 2009, this paper performs the Mann–Kendall test and calculates the trend Slope (β) and Hurst index of time series data to study the temporal trends and long-range dependence of Normalized Difference Vegetation Index (NDVI) on 1 km spatial scale, and plots monthly calendar and seasonal succession map using spatial analysis techniques, and then analyze and reveal the spatial–temporal characteristics of vegetation coverage. Main findings are as follows: (1) dense vegetation coverage mainly distribute in mountainous and hilly areas dominated by forest and shrub, followed by vast plain areas with well developed agricultural industry, and low vegetation coverage mainly distribute along part of coastal beaches, surrounding most of urban areas and large inland water bodies and in the semi-arid agro-pasture intertwined zone at the north-west corner of Hebei province. (2) Overall, vegetation coverage is high in summer–autumn and low in winter–spring and the increasing trend from 1999 to 2009 on monthly, seasonal and annual scales are significant in most areas. An increased seasonal difference is detected because the improving trend of vegetation coverage in growing seasons is more remarkable than that in non-growing seasons. Furthermore, significant long-range dependence of NDVI time series is detected in most areas which indicate that the trend of vegetation coverage change from 1999 to 2009 will definitely persist in the near future. (3) Both variation of vegetation coverage in the past and its long-range dependence show significant spatial differences on macro spatial scale, in detail, improving trend of vegetation coverage in Liaoning province is very significant and it will persist in the near future because more than 85% of the pixels in Liaoning province has positive Slope (β) and Hurst index great than 0.5, correspondingly, only very mild signal of enlarged seasonal difference is detected in Liaoning province. On the contrary, very large extent of vegetation coverage in Beijing–Tianjin–Hebei area and Shandong province show significant degrading trend and enlarged seasonal difference despite the overall improving trend in these areas in the past 11 years. Areas with degrading trend of vegetation coverage in the past and future trends point to continuing degrading account for 6.71% and 9.84% in Beijing–Tianjin–Hebei area and Shandong province, respectively, while it is below 6.00% in Liaoning province. (4) Areas with degrading trend of vegetation coverage in the past and future trends point to continuing degrading show the overall spatial pattern of scattering on macro scale and aggregating on fine scales, specifically, areas surrounding large inland water bodies, along part of coastal beaches and surrounding urban areas indicates strong tendency of degrading in the past and prospective degrading trend in the near future. (5) Complicated driving forces of vegetation coverage change on macro spatial scale are revealed by the spatial patterns of the coupling index between Slope (β) and Hurst index, in detail, rapid and extensive urbanization undergone on multi-spatial scales is the most important man-made force of vegetation coverage degrading, large scale agricultural activities overall improve the vegetation coverage and enlarge its seasonal difference; while factors include water level changes near large inland water bodies, water–salt dynamics at coastal beach and so on are the main natural driving forces of vegetation degradation. The findings in this paper are useful for wise regional ecosystem management in Circum Bohai Bay Region.     

A novel and highly efficient production system for recombinant adeno-associated virus vector

Recombinant adeno-associated virus (rAAV) has proven to be a promising gene delivery vector for human gene therapy. However, its application has been limited by difficulty in obtaining enough quantities of high-titer vector stocks. In this paper, a novel and highly efficient production system for rAAV is described. A recombinant herpes simplex virus type 1 (rHSV-1) designated HSV1-rc/AUL2, which expressed adeno-associated virus type2 (AAV-2) Rep and Cap proteins, was constructed previously. The data confirmed that its functions were to support rAAV replication and packaging, and the generated rAAV was infectious. Meanwhile, an rAAV proviral cell line designated BHK/SG2, which carried the green fluorescent protein (GFP) gene expression cassette, was established by transfecting BHK-21 cells with rAAV vector plasmid pSNAV-2-GFP. Infecting BHK/SG2 with HSV1-rc/AUL2 at an MOI of 0.1 resulted in the optimal yields of rAAV, reaching 250 transducing unit (TU) or 4.28×104 particles per cell. Therefore, compared     

Influence of heme and vitamin B12 on growth and fermentations of Bacteroides species.

We examined the effects of heme on the growth and fermentations of Bacteroides species. Bacteroides fragilis ATCC 25285 required heme for growth and produced malate and lactate as major products of glucose fermentation when the concentration of heme was 1 ng/ml. With 1 microgram of heme per ml, malate was not formed, lactate production decreased, and succinate and acetate were the major fermentation products. B. eggerthii ATCC 27754 grew without heme, with the production of mainly malate and lactate from glucose. Its fermentation with 1 microgram of heme per ml was similar to that of B. fragilis grown with the same concentration of heme. B. splanchicus VPI 6842 grew without heme, with the production of mainly malate, acetate, and H2 from glucose. With 1 microgram of heme per ml, malate disappeared, H2 decreased significantly, and succinate, acetate, and butyrate were the major products. The addition of vitamin B12 to media containing 1 microgram of heme per ml caused all species to produce propionate at the expense of succinate and, with B. splanchnicus, also at the expense of butyrate. Thus, the concentration of heme and the presence of vitamin B12 significantly influenced the course of glucose fermentation by these bacteria.     

中蜂处女王性成熟日龄及其交尾习性的探讨

本研究对210只人工培育的出房后1,2,3,4,6,8．10日龄的中蜂处女王受精囊液的pH值进行测定．结果表明,1日龄处女王受精囊液的pH值平均为7．7,2日龄为8．5,从3日龄开始达到最高值8.8．并保持稳定状态,由此判断出房后3日龄的中蜂处女王性已成熟．通过对72只中蜂处女王交尾飞行的观察,结果表明,蜂王交尾日龄多为6-8日．最早为4日龄,最迟为16日龄;处女王认巢飞行持续时间平均为7．4分钟,交尾飞行平均为21．5分钟：处女王连续交尾飞行1-3次,有9只处女王在一天里进行2次交尾飞行．     

A tightly associated serine/threonine protein kinase regulates phosphoinositide 3-kinase activity.

We identified a serine/threonine protein kinase that is associated with and phosphorylates phosphoinositide 3-kinase (PtdIns 3-kinase). The serine kinase phosphorylates both the 85- and 110-kDa subunits of PtdIns 3-kinase and purifies with it from rat liver and immunoprecipitates with antibodies raised to the 85-kDa subunit. Tryptic phosphopeptide maps indicate that p85 from polyomavirus middle T-transformed cells is phosphorylated in vivo at three sites phosphorylated in vitro by the associated serine kinase. The 85-kDa subunit of PtdIns 3-kinase is phosphorylated in vitro on serine at a stoichiometry of approximately 1 mol of phosphate per mol of p85. This phosphorylation results in a three- to sevenfold decrease in PtdIns 3-kinase activity. Dephosphorylation with protein phosphatase 2A reverses the inhibition. This suggests that the association of protein phosphatase 2A with middle T antigen may function to activate PtdIns 3-kinase.     

Production of a Novel Compound, 7,10,12-Trihydroxy-8(E)-Octadecenoic Acid from Ricinoleic Acid by Pseudomonas aeruginosa PR3

The production and its potential use of a novel trihydroxy unsaturated fatty acid, 7,10,12-trihydroxy-8(E)-octadecenoic acid (TOD), were investigated. TOD was formed by Pseudomonas aeruginosa PR3 (NRRL B-18602) in a culture supplied with exogenous ricinoleic acid. The yield of TOD production was always higher in a rich culture medium than in minimal screening medium. Extending the conversion time from 48 to 72 h prior to lipid extraction led to a 65% reduction in yield, indicating that TOD was further metabolized by strain PR3 and that control of reaction time is important to achieving a maximum yield. The optimum culture density, reaction time, pH, temperature, and substrate concentration for the production of TOD were: 20–24 h culture growth, 48 h, 7.0, 25°C, and 1% (vol/vol), respectively. Under optimum conditions, the yield of TOD production was greater than 45%. TOD was found to be an antifungal agent most active against the fungus that causes blast disease in rice plants, the most important fungal disease affecting rice production worldwide. Received: 4 January 2001/Accepted: 6 February 2001     

蛋白酪氨酸激酶在类风湿性关节炎滑膜细胞中的表达和功能

克隆类风湿性关节炎（RA）滑膜细胞（FLS）中的蛋白酪氨酸激酶（PTKs）,并研究它们在RA滑膜细胞异常增殖和侵软骨中的作用。根据巳知的PTKs氨基酸序列保守区设计简并引物,采用3'快速末端扩增法（3'RACE)扩增滑膜细胞中PTKs cDNAs的3'末端,将所得序列与Genebank中序列进行比较,以鉴定其是否为巳知的PTKs或与PTKs同源的新序列,然后通过RNA点杂交方法分别观察这些PTKs在RA和骨性关节炎（OA）病人滑膜细胞中的表达水平。结果表明,从RA FLS中克隆到6种巳知PTKs的cDNAs片段,分别为血小板衍生生长因子受体A（PDGFRA）、胰岛素生长因子-1受体（IGF1R）、含discoidin结构域的受体型酪氨酸激酶（DDR2）、Lyn、Janus激酶1（JAK1）和TYK2。RNA点杂交结果显示,在4个RA病人和2个OA病人的滑膜细胞中,PDGFRA、IGF-1R和DDR2在RA滑膜细胞中的表达水平高于OA滑膜细胞,其它几处激酶在两种细胞中的表达水平相同。说明RI滑膜细胞中至少表达PDGFR、IGF1R、Lyn、DDR2、JAK1和TYK2等6种PTKs,其中PDGFRA、IGF1R和DDR2可能与RA滑膜细胞的过度增殖和对软骨的侵蚀性相关。     

Lateral diffusion of membrane-spanning and glycosylphosphatidylinositol-linked proteins: toward establishing rules governing the lateral mobility of membrane proteins.

In the plasma membrane of animal cells, many membrane-spanning proteins exhibit lower lateral mobilities than glycosylphosphatidylinositol (GPI)-linked proteins. To determine if the GPI linkage was a major determinant of the high lateral mobility of these proteins, we measured the lateral diffusion of chimeric membrane proteins composed of normally transmembrane proteins that were converted to GPI-linked proteins, or GPI-linked proteins that were converted to membrane-spanning proteins. These studies indicate that GPI linkage contributes only marginally (approximately twofold) to the higher mobility of several GPI-linked proteins. The major determinant of the high mobility of these proteins resides instead in the extracellular domain. We propose that lack of interaction of the extracellular domain of this protein class with other cell surface components allows diffusion that is constrained only by the diffusion of the membrane anchor. In contrast, cell surface interactions of the ectodomain of membrane-spanning proteins exemplified by the vesicular stomatitis virus G glycoprotein reduces their lateral diffusion coefficients by nearly 10-fold with respect to many GPI-linked proteins.     

Safe To Walk? Neighborhood Safety and Physical Activity Among Public Housing Residents

Background

Despite its health benefits, physical inactivity is pervasive, particularly among those living in lower-income urban communities. In such settings, neighborhood safety may impact willingness to be regularly physically active. We examined the association of perceived neighborhood safety with pedometer-determined physical activity and physical activity self-efficacy.

Methods and Findings

Participants were 1,180 predominantly racial/ethnic minority adults recruited from 12 urban low-income housing complexes in metropolitan Boston. Participants completed a 5-d pedometer data-collection protocol and self-reported their perceptions of neighborhood safety and self-efficacy (i.e., confidence in the ability to be physically active). Gender-stratified bivariate and multivariable random effects models were estimated to account for within-site clustering. Most participants reported feeling safe during the day, while just over one-third (36%) felt safe at night. We found no association between daytime safety reports and physical activity among both men and women. There was also no association between night-time safety reports and physical activity among men (p = 0.23) but women who reported feeling unsafe (versus safe) at night showed significantly fewer steps per day (4,302 versus 5,178, p = 0.01). Perceiving one''s neighborhood as unsafe during the day was associated with significantly lower odds of having high physical activity self-efficacy among both men (OR 0.40, p = 0.01) and women (OR 0.68, p = 0.02).

Conclusions

Residing in a neighborhood that is perceived to be unsafe at night is a barrier to regular physical activity among individuals, especially women, living in urban low-income housing. Feeling unsafe may also diminish confidence in the ability to be more physically active. Both of these factors may limit the effectiveness of physical activity promotion strategies delivered in similar settings.