Expression pattern of GASA,downstream genes of DELLA,in Arabidopsis

Separation and functional research of related components involved in gibberellins （GAs） signaling are important to clarify the mechanism of GA functioning. Research on the downstream components of DELLA, the key factor of the GA signaling pathway, is limited at present. GASA （GA-Stimulated in Arabidopsis） family contains 15 genes usually regulated by GA in Arabidopsis thaliana. All GASA proteins have a cleavable signal peptide in N terminus and a conserved GASA domain including 12 cysteines in C terminus. RT-PCR analysis revealed that the expression of GASA4 and GASA6 were down-regulated, but GASA 1 and GASA9 were up-regulated in the DELLA mutants, gai-t6 and rga-24, as well as the double mutant, consisting with the results that GASA4 and GASA6 were induced, but GASA1 and GASA9 were inhibited by exogenous GA3. In addition, the expression patterns of other GASA genes were regulated by GA and ABA, separately or cooperatively. Most of GASA genes were expressed in roots, stems, leaves, flowers and developing siliques. GUS gene driven by the promoters of GASA6, GASA7, GASA8, GASA9, GASAIO, GASA11 and GASA12were used as reporters and it was found that all GASA genes expressed in the growing and differentiating organs and abscission zones, suggesting the role of these genes in cell growth and differentiation. This study provided an important basis for functional study of the GASA gene family in the GA and ABA signaling pathway.     

Rank of loop, constraint degree of path, coupling degree of graph and their application

Some new concepts (rank of a loop, degree of freedom of a graph, path unit and ordered path arrangement, constraint degree of path, coupling degree of a graph, basic graph, etc. ), formulas, and algorithms, are proposed in this paper. Based on these concepts, a new systematic theory and practical method for the design of topological structure, kinematics and dynamics of mechanical systems is established. Some conjectures and problems needed to be researched are also put forward. The concepts, formulae and algorithms presented in this paper will find wide potential applications.     

History of School of Mechanical Engineering, Tsinghua University

Mechanical engineering is one of the earliest established disciplines in Tsinghua University. In 1932, the Department of Mechanical Engineering was established, comprising an aeronautical teaching group and an automobile teaching group. In the late 1940s, the enrollment of the department was already the largest among all engineering     

Palaeodietary study of Sanxingcun Site, Jintan, Jiangsu

C and N stable isotope ratios of 19 human bones in Sanxingcun Site, Jintan, Jiangsu Province, were measured to explore the lifestyle and social economic structure. Although the bone collagen degraded to different extents, the atomic ratio of C/N was located in the range of 2.9-3.6, indicating that they were preserved very well. Average δ13C value (20.05±0.21‰), average δ 15N value (9.69 ±0.33‰) and poor positive correlation between each other suggested that rice agriculture was dominant with hunt-ing-fishing supplemented in human lifestyle. Poor negative correlation between δ 15N values and C3 percentages of foods implied relative independence of rice agriculture and hunting-fishing. Compared to Hemudu Site and Qingpu Site, rice agriculture was developed further, but hunting-fishing decreased. The mode for people in Sanxingcun Site to get the meat was still in the initial exploitation.     

Complete mitochondrial DNA sequence of Chinese alligator,Alligator sinensis, and phylogeny of crocodiles

The 16746-neueleotide (nt) sequence of mitochondrial DNA(mtDNA) of Chinese alligator,Alligator sinensis,was determined using the Long-PCR and primer walking methods.As is typical in vertebrates,the mtDNA encodes 13 proteins,2 rDNA,22 tRNA genes,and a noncoding control region.The Composition of bases is respectively 29.43%A,24.59%T,14.86%G,31.12% C.The gene arrangement differs from the common vertebrate gene arrangement,but is similar to that of other crocodiles,DNA sequence data from 12S rRNA,168 rRNA,protein-coding genes and combined sequence data were used to reconstruct the phylogeny of reptiles with the MP and ML methods.With this large data set and an appropriate range of outgroup taxa,the authors demonstrate that Chinese alligator is most closely related to American alligator among three crocodilian species,which suppors the traditional viewpoint.According to the branch lengths of ML tree from the combined data set,the primary divergence between Alligator and Caiman genus was dated at about 74.9 Ma,the split between Chinese alligator and American alligator was dated at 50.9Ma.     

Discovery of Cathaysiodendron Lee from the Early Carboniferous of Jingyuan, Gansu, western China

As one of the representative members of the Late Palaeozoic Cathaysian flora, Cathaysiodendron has been previously recorded from the Early Permian Taiyuan and Shanxi Formations in north China. The species of Cathaysiodendron presented here are from the lower member of Chouniugou Formation of Ciyao, Jingyuan, Gansu. The overlying marine beds yield fusulinids that are of Visean age in western Europe and conodonts of the Datang Stage in south China, so that the age of the bed containing Cathaysiodendron as Visean, Early Carboniferous, is well constrained. Such a record of Cathaysiodendron is significant in terms of Carboniferous phytogeography and the evolution of the Cathaysian Lepidophytes. A new species, Cathaysiodendron jingyuanense Wang & Wu sp. nov. is described and a second one mentioned.     

Status monitoring and health assessment of Luhuitou fringing reef of Sanya, Hainan, China

The monitoring survey and health assessment for benthic community were carded out in Luhuitou fdnging reef of Sanya, Hainan, China in 2002. Monitoring survey included manta tow, line intercept transect, video transect and digital photograph. The mean live coral cover was 23.40%. Comparison of used monitoring methods showed that video transect can replace line intercept transect, and 50 m transect is better than 20 m transect in uneven coral region. Survey data and comparison with previous research work showed that Luhuitou fringing reef has been damaged severely and has a general declining trend with live coral cover from about 85% in the 1960s down to 20% in 2004, but it still has quite high biodiversity and therefore has special protection value. Main factors of Luhuitou fdnging reef declining were human activities including reef rock digging and curios collecting, destructive fishing, sediment and pollutant from coastal land, and recent marine aquaculture. Only strengthening integrated management can reach improvement and restoration of Luhuitou declining coral reef ecosystem.     

Star of Zhejiang University, sparkle of China＇s energy, fire of human development —— Publishing of “Advanced Combustion”

Showing great foresight, based on the advantage of having a national key subject as well as superbly qualified scientific and technical staff in advanced combustion energy theory and practice, the Zhejiang University Press, under the sponsorship of National Scientific and Techno-     

Diversity of Plant Species of Alpine Grassland in Nakchu of Tibet, China

0Introduction Biologicaldiversityconcernedwiththesumofvariouslivingbeingsandtheirprocesses,aswellasthebasisofharmonious coexistencebetweenmanandnatureplaysanimportantroleinecology,economy,esthetics,ethics,etc.Duetodeteriorationofglobal environment,acceler…     

Director of Editorial Development, ISI, Visits Tsinghua University

Dr. James Testa, Director of Editorial Development of ISI (Institute for Scientific Information), visited Tsinghua on October 17, 2005. Tsinghua Vice President Kang Kejun had a talk with Dr. Testa. On behalf of the university, Vice President Kang welcomed Testa to Tsinghua, noting that as a world-famous institute, ISI has contributed a lot to scientific research. Vice President Kang emphasized the importance of international exchange of research and gave an outline of Tsinghua’s r…     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs. The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with atotal thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ^58O values of dolomited burrow infills (-5.9‰～-7.8‰,PDB) and matrix dolomites (-6. 6‰～-8. 1‰, avg. -7. 4‰PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its ^87Sr/Sr^86 ratios (0. 7084～0. 7088) that are higher than suggested for the late Ordovician seawaters (0. 7078～0. 7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to “cannibalization“ of earlier replacement dolomite during the chemical compaction.     

Influence of Ag content on the microstructure,mechanical, and tribological properties of TaVN-Ag films

A series of TaVN-Ag nanocomposite films were deposited using a radio-frequency magnetron sputtering system. The microstructure, mechanical properties, and tribological performance of the films were investigated. The results showed that TaVN-Ag films were composed of face-centered cubic (fcc) TaVN and fcc-Ag. With increasing Ag content, the hardness of TaVN-Ag composite films first increased and then decreased rapidly. The maximum hardness value was 31.4 GPa. At room temperature, the coefficient of friction (COF) of TaVN-Ag films decreased from 0.76 to 0.60 with increasing Ag content from 0 to 7.93at%. For the TaVN-Ag films with 7.93at% Ag, COF first increased and then decreased rapidly from 0.60 at 25℃ to 0.35 at 600℃, whereas the wear rate of the film increased continuously from 3.91×10-7 to 19.1×10-7 mm3/(N·mm). The COF of the TaVN-Ag film with 7.93at% Ag was lower than that of the TaVN film, and their wear rates showed opposite trends with increasing temperature.     

A new Euprox from the Late Miocene of Yuanmou,Yunnan Province,China,with interpretation of its paleoenvironment

The Yuanmou Basin of Yunnan Province is a hotspot for the research of early homind evolution and its environmental background.During the implementation of the Program“Research of the Origin and Evolution of Early Man and Its Environmental Baqckground” from 1998 to 2001,a huge quantity of hominoid and mammal fossils were collected.The present report systematically describes an Euprox robustus sp.nov.identified during the recent laboratory work on the collected material.Euprox is a group of earliest cervids with true antlers.The new species is the third one of the genus discovered in China.Judged by its morphologic characteristics,the new species feed on juicy and tender leaves of dicotyledon.It implies that the vegetation of its epoch in the Yuanmou Basin is a kind of southern subtropical evergreen forest and the climate is humid and temperate with evident seasonality.The latter is mostly influenced by the monsoon and secondly by the latitude.     

Stability of patches of oasis landscape in arid areas:A case study of Sangong River Watershed,Xinjiang,China

The stability of oases is one of the key scientific issues in the process of evolution and management of oases in arid areas. The stability of oases and its representation are also different at different scales. This paper deals with the stability of oases at the landscape patch scale with a case study in the Sangong River Watershed of Tianshan Mountains. We employed the remote sensing, geographic information system and mathematical statistical methods to process the remote sensing images of three periods in 1978, 1987 and 1998, and put forward the approaches for representing the oasis stability at the landscape patch scale. The landscape control capacity of oasis patches is a kind of natural driving forces of the dynamic landscape change. The control capacity of a certain patch type on landscape change increases with its area and shape complexity and contrasts between it and other patches, and reduces with its spatial distances between it and other patches. The patch type with the strongest control capacity should be the matrix of landscape. The conversion of oasis landscape patches results from both natural and anthropogenic driving forces, particularly the anthropogenic driving forces. The higher the conversion proportion is, the lower the stability of patch types is and the stronger the anthropogenic disturbance is. The patch type with the strongest net control capacity in the Sangong River Watershed in 1987 was the desert grassland, which was the matrix of landscapes; but the matrix of landscapes had been changed into the irrigated lands in 1987 and 1998. The control capacities of landscape patches on the oasis landscape evolution have gradually reduced with time in the Sangong River Watershed, and the change extents also have reduced gradually. This reveals that the interaction among the landscape patch types generally tends to reduce, and the natural stability of the oasis landscape patches generally tends to increase. However, the conversion among the landscape patches occurs more frequently due to the increase of intensive human activities, which probably causes the lower stability of environmental resources patch and higher stability of introduced patches in the oasis landscape.     

Research of Degumming Process, Microstructure and Properties of Mulberry Fiber

More and more novel nature fibers are used in textiles. The natural fibers include banana fiber, pineapple fiber and bamboo fiber etc. In this paper, as a kind of novel natural fiber, mulberry fiber is studied. The chemical component of mulberry bast is tested and analyzed. Meanwhile, the degumming method and process of mulberry bast are studied. Chemical degumming experiments to investigate the influence of alkali concentration, alkali boiling time and sodium phosphate tribasic ratio to material are conducted. Consequently, optimum parameters are obtained. The crystallinity of mulberry fiber is tested by using X-ray line, and the photos of scanning electron microscope （SEM） are observed. Testing results of the fiber properties （e. g. fineness, tenacity, length and elongation） show that mulberry fiber can be spun blend with cotton.     

Age-Structure and Dynamic of Dominant Population of Castanopsis carlesii Community in Dujiangyan City, Sichuan, China

0Introduction Theevergreenbroad leavedforestareaofwesternSichuanbasinisanarrowregionfromnorthtosouth.Itformsatopography protectivescreencalledas“famoushighprecipitationareaofwesternChina”with especiallyplentifulprecipitationandmuchstorm.Itisanimportantd…     

Age-Structure and Dynamic of Dominant Population of Castanopsis carlesii Community in Dujiangyan City, Sichuan, China

It analyses the Castanopsis carlesii, Camellia oleifera and Symplocos laurina populations‘ status and role in the Castanop.sis carlesii community basing on the study on the dominant population size structure, survival curve and dynamic. It reveals the Castanopsis carlesi population acts as a main role in the community which maintains the stabilization and renovation of the community. The populations of Camellia oleifera and Symplocos laurina act as a secondary position. The development and succession dynamics of dominant populations is also discussed. The management method is preliminary draw nout which offers a theoretical basis for the evergreen broad-leaved forest restoration and reconstruction in the lower hilly of the west edge of the Sichuan basin.