A gradient analysis based on the buffer zones of urban landscape pattern of the constructed area in Guigang City, Guangxi, China

Over the last century urbanization on the landscape has increased and intensified. Urban development has a great impact on the environment at the local, regional and even global levels. As a driving force in global change, the need to understand the dynamics of urban pattern and its change in an accurate and efficient manner is ever more pressing. Based on aerial color infrared photography in 1985 and QuickBird satellite imagery in 2004 and according to the standard for plan and construction of city land use, the landscape of Guigang City was divided into 11 types. In the landscape classification maps, 31 buffer zones, each being 200 m wide, were divided. With the aid of GIS software ArcView 3.2 and landscape pattern analysis software FRAGSTATS 3.3, the landscape spatial patterns of each buffer zone were analyzed at the landscape level and class level. The landscape indices, such as patch size, patch fractal dimension, diversity index and evenness index, were calculated. The results indicated the following: The total area of the residential land and the communal land in 2004 covered 46.3% of the entire constructed area of Guigang City and the sum of the patch number of the two patch types occupied about 39.7% of the total patch number, while the percentages were respectively 48.2% and 45.4% in 1985. This showed that the mosaic landscape with the residential land and communal facilities land became increasingly unclear following urban development and landscape diversity. Based on the gradient analysis with the landscape-level index and the class-level index, there were two business and finance centers in the constructed area. One was located in the urban center with a range of 0.8 km; the other was from the 10^th to the 16^th zone. In each buffer zone, the mean patch size was larger and the landscape shape was more regular in 2004 than in 1985. Furthermore, the Shannon diversity index of each buffer zone rose in 2004 with patch richness and evenness increasing. The landscape index computed for the main landscape types (communal facilities land, industrial estate land, residential land and farmland) in the middle of the buffer zones clearly indicated the changes taking place in urbanization. The patch size and the patch number of industrial estate land and farmland also pointed to these changes, while communal facilities land and residential land assumed another similar tendency towards changes. In each gradient zone, industrial estate land had the most complex shape, the lowest area percentage of each zone and the biggest mean patch size, whereas communal facilities land and residential land were opposite to industrial estate land. Farmland had a steady percentage along the buffer zone and its continuous distribution had an important impact on the urban eco-environment. The question of how to relate the pattern of changing characteristics along the buffer zone to the urban ecological process and urban ecological planning remains to be studied further in the future.     

光系统II核心复合物的稳态荧光光谱(英文)

在 83K 和 160K 两个温度下,通过激发波长对荧光发射谱的影响研究了光系统II中核心复合物的荧光光谱特性。用不同波长的光激发,核心复合物的发射谱的最大发射峰值不变,用 480、489、495 和 507nm 的光分别激发核心复合物,其光谱最大峰值处的荧光强度随不同激发波长下β-胡萝卜素分子的吸收强度的增大而降低,在长波长区域光谱的变化依赖于首先被激发的色素分子。所以,激发波长的不同影响着核心复合物中能量传递的途径。通过高斯解析,分析出核心复合物中至少存在有 7组叶绿素a组分,它们是Chla660,Chla670,Chla680,Chla682,Chla684,Chla687和Chla690。     

Recent approach to Buchia biostratigraphy from the Tethyan Himalaya area, China

Recent collections from six sections in Lanongla area, Tethyan Himalaya allow the establishment of four buchia assemblages. In ascending order, they are Buchia-Buchia spitiensis, Buchia masquensis-Buchia rugasa, Buchia blanfordiana, Buchia piochii and Buchia subokensis assemblages. These Buchia assemblages first demonstrate that not only the Upper Jurassic strata but also the highest Buchia assemblage-Buchia subokensis, which appeared in Lower Cretaceous strata all over the world are present in Lanongla area. This first records the highest Buchia assemblage in Lanongla area. __________ Translated from Acta Scientiarum Naturalium Universitatis Pekinensis, 2005, 41 (4) [译自: 北京大学学报( 自然科学版), 2005,41(4)]     

Smad7-induced beta-catenin degradation alters epidermal appendage development

To assess whether Smad signaling affects skin development, we generated transgenic mice in which a Smad antagonist, Smad7, was induced in keratinocytes, including epidermal stem cells. Smad7 transgene induction perturbed hair follicle morphogenesis and differentiation, but accelerated sebaceous gland morphogenesis. Further analysis revealed that independent of its role in anti-Smad signaling, Smad7 bound beta-catenin and induced beta-catenin degradation by recruiting an E3 ligase, Smurf2, to the Smad7/beta-catenin complex. Consequently, Wnt/beta-catenin signaling was suppressed in Smad7 transgenic hair follicles. Coexpression of the Smurf2 and Smad7 transgenes exacerbated Smad7-induced abnormalities in hair follicles and sebaceous glands. Conversely, when endogenous Smad7 was knocked down, keratinocytes exhibited increased beta-catenin protein and enhanced Wnt signaling. Our data reveal a mechanism for Smad7 in antagonizing Wnt/beta-catenin signaling, thereby shifting the skin differentiation program from forming hair follicles to sebaceous glands.     

LncRNA H19: A novel oncogene in multiple cancers

Long non-coding RNAs (lncRNAs) are a series of non-coding RNAs that lack open reading frameworks. Accumulating evidence suggests important roles for lncRNAs in various diseases, including cancers. Recently, lncRNA H19 (H19) became a research focus due to its ectopic expression in human malignant tumors, where it functioned as an oncogene. Subsequently, H19 was confirmed to be involved in tumorigenesis and malignant progression in many tumors and had been implicated in promoting cell growth, invasion, migration, epithelial-mesenchymal transition, metastasis, and apoptosis. H19 also sequesters some microRNAs, facilitating a multilayer molecular regulatory mechanism. In this review, we summarize the abnormal overexpression of H19 in human cancers, which suggests wide prospects for further research into the diagnosis and treatment of cancers.     

Combination Treatment with Resveratrol and Sulforaphane Induces Apoptosis in Human U251 Glioma Cells

Resveratrol is a naturally occurring polyphenolic compound highly enriched in grapes, peanuts, red wine, and a variety of food sources. Sulforaphane belongs to the family of isothiocyanates and is highly enriched in cruciferous vegetables. Our previous study showed that resveratrol, when used at high concentrations, inhibited cell proliferation, caused the cell cycle arrest and induced apoptotic cell death in glioma cells. In the current study, we tested the effect of combination treatment with resveratrol and sulforaphane, when both were used at low concentrations, on cell proliferation, migration and death in human U251 glioma cells. Our study shows that combination treatment with resveratrol and sulforaphane inhibits cell proliferation and migration, reduces cell viability, induces lactate dehydrogenase release, decreases pro-survival Akt phosphorylation and increases caspase-3 activation. The use of combination of bioactive food components, such as resveratrol and sulforaphane, may be a viable approach for the treatment of glioma.     

苦马豆和披针叶黄华种子硬实特性与活力关系

将苦马豆和披针叶黄华种子在恒温25℃下吸胀,每24 h取出吸胀种子,16 d后未吸胀的种子为硬实种子（H）,硬实种子用硫酸处理后恒温吸胀24 h,与非硬实种子进行发芽试验和各项活力指标测定。结果显示每日内吸胀的种子数量随时间推移以一定比列下降,苦马豆非硬实种子第3天后吸胀率下降到1%,第13～16天突然上升后又下降到1%,披针叶黄华非硬实种子第3天后下降到1%,第9、10天突然上升后又下降到1%。两种豆类都显示出硬实种子发芽率、发芽指数、活力指数、脱氢酶活性、呼吸速率和超氧化物歧化酶（SOD）活性均高于非硬实种子,而电导率、浸出液可溶性糖和丙二醛（MDA）含量低于非硬实种子,缓慢吸胀的硬实种子活力指标高于快速吸胀的硬实种子,这表明硬实种子活力高于非硬实种子,硬实种子吸胀过程中存在吸胀损伤。而在非硬实种子中,根据以上活力指标判断,晚吸胀的种子比早吸胀的种子活力高。     

Significance of consensus CYC-binding sites found in the promoters of both ChCYC and ChRAD genes in Chirita heterotricha (Gesneriaceae)

CYC-like genes are widely conserved in controlling floral dorsoventral asymmetry (zygomorphy) through persistent expression in corresponding domains in core eudicots. To understand how CYC-like gene expression is maintained during flower development, we selected Chirita heterotricha as a material and isolated the promoter sequences of the ChCYCIC and ChCYCID genes, homologs of CYC, by inverse polymerase chain reaction. Further promoter analyses led to the identification of a putative cis-regulatory element in each promoter matching the consensus DNA binding site for Antirrhinum CYC protein: GGCCCCTC at-165 for ChCYC1C, and GGCCCCCC at-163 for ChCYCID. This indicates that both the ChCYCIC and ChCYC1D genes have probably evolved autoregulatory loops to sustain their expression in developing flowers. We also isolated the coding and promoter sequences of the ChRAD gene, a homolog of Antirrhinum RAD. Promoter analysis showed that the ChRAD gene promoter also contained a putative CYC-binding site (GGCCCAC at -134). Therefore, ChRAD is likely a direct target of the ChCYC1 genes, which is similar to Antirrhinum RAD. These results imply that the establishment of floral zygomorphy in Chirita may have been achieved by the evolution of an autoregulatory loop for CYC-like genes,which was probably accompanied by simultaneous co-option of the RAD-like gene into their regulatory network.     

Discovery of 1H-benzo[d][1,2,3]triazol-1-yl 3,4,5-trimethoxybenzoate as a potential antiproliferative agent by inhibiting histone deacetylase

Twenty-one benzotriazoles (3-16 and 18-24) were synthesized and half of them (5, 8-16, 20, and 21) were reported for the first time. Their antiproliferative activities against three human cancer cells were assayed. It revealed that 1H-benzo[d][1,2,3]triazol-1-yl 3,4,5-trimethoxybenzoate (9) showed considerable activity against three human cancer cell lines with the half maximal inhibitory concentration (IC(50)) values of 1.2-2.4 nM, which were close to the value of the positive control, doxorubicin. Further investigation indicated compound 9 was a potential histone deacetylase inhibitor (IC(50)=9.4 μM) and its binding mode was simulated using docking method.     

中国洞穴甲壳动物多样性及其对洞穴环境的适应性

简要阐述了洞穴环境的研究现状以及洞穴动物的生态特征,初步探讨了中国洞穴甲壳动物的形成过程、多样性、地理分布以及对洞穴环境的适应性。截止到2008年10月,我国已记录的洞穴甲壳动物(主要指十足目虾类和端足目钩虾类)共有33种,分别隶属6科10属,主要分布在贵州省、广西省等喀斯特洞穴密集地区。洞穴甲壳动物由于长期生活在洞穴的黑暗带,食物匮乏,水温恒定,CO2浓度过高,且O2浓度相对较少的环境中,其在形态结构、消化系统、生理及行为等方面逐渐表现出与地表甲壳动物不同的适应性特征。如:眼缺失、体无色、触角和附肢显著增长、新陈代谢减慢、代谢率小,昼夜节律降低,不能调节体温,生活步调放慢,寿命长,发育周期长等。