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Input function and simulated distributions of tritium in the North Pacific

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Science china Earth sciences 2010年第3期53卷 441-453页

作者： BA Qi1,2 & XU YongFu1 1 state key laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, institute of Atmospheric Physics, chinese academy of sciences, beijing 100029, china 2 Graduate University of chinese academy of sciences, beijing 100049, china state key laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Graduate University of chinese academy of sciences Beijing China

An ocean general circulation model (OGCM) of the North Pacific with a southern open boundary condition is used to simulate the distribution and transport of tritium in the North Pacific. First, the observed tritium in precipitation dataset of GNIP/ISOHIS is chosen, and used to develop an input function of tritium for the model domain from 1951 to 1997 in terms of the triangulation for interpolation. Then, the input function is used as an upper flux for the tritium model. The OGCM with tritium is integrated for 47 years with the initial condition of zero tritium concentrations. Compared with the observations from GEOSECS and WOCE, the model generates a meridional gradient of surface tritium concentrations and the high tritium concentrations in the subsurface layer, which is consistent with that indicated in the observations. The simulated time series of total tritium fluxes from the atmosphere to the ocean shows a spike in 1963. The total inventory of tritium in the ocean changes slowly with time after 1975. Tritium enters the higher-latitude region, and then is mainly transported by the subsurface process towards the equatorial region, which is well simulated in the model. However, the difference mainly occurs at 30°N–40°N, which can be seen also in the simulation of CFCs. This difference may partly originate from the insufficient description of physical processes in the OGCM. Nevertheless, some uncertainties exist in the development of the tritium input function, which can also influence the simulated results.

关键词： North Pacific basin-wide ocean general circulation model tritium input function tritium distributions

维普期刊数据库

Negative regulation of TGF-β signaling in development

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Cell Research 2004年第6期14卷 441-449页

作者： Ye Guang CHEN, An Ming MENG The state key laboratory of biomembrane and membrane Biotechnology, Department of Biological sciences and Biotechnology, Tsinghua University, beijing 100084, china Department of Biological sciences and Biotechnology The State Key Laboratory of Biomembrane and Membrane Biotechnology Tsinghua University Beijing China

The TGF-β superfamily members have important roles in controlling patterning and tissue formation in both invertebrates and vertebrates. Two types of signal transducers, receptors and Smads, mediate the signaling to regulate expression of their target genes. Despite of the relatively simple signal transduction pathway, many modulators have been found to contribute to a tight regulation of this pathway in a variety of mechanisms. This article reviews the negative regulation of TGF-β signaling with focus on its roles in vertebrate development.

关键词： TGF-β BMP Nodal Activin antagonist development negative regulation.

Interdecadal trend turning of global terrestrial temperature and precipitation during 1951-2002

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Progress in Natural Science:Materials International 2008年第11期18卷 1383-1393页

作者： Xiaohui Shi Xiangde Xu state key laboratory of Severe Weather,chinese academy of Meteorological sciences,beijing 100081,china state key laboratory of Severe Weather Chinese Academy of Meteorological Sciences Beijing 100081 China

A grid-by-grid counting of interdecadal trend turning(ITT)of annual mean surface air temperature(SAT)and total precipitation at 67,359 terrestrial grids in the period 1951-2002 is *** analysis of the last ITTs of SAT and total precipitation in the period,in the context of both occurrence time and linear trends after the breakpoint,indicates that a warming trend has become highly significant across most reagent of the world in the late 20th *** terrestrial grids have recorded an ITT of total precipitation in either the 1970s or 1980s,and 45.7% of the terrestrial grids in the study have seen a decreasing trend in total annual precipitation after the break- point,with the remaining 54.3% having experienced an increasing ***,global terrestrial regions have experienced either an increasingly warm and dry climate or an increasingly warm and wet *** analysis of ITT of regional mean SAT and total pre- cipitation in 22 regions shows that the Northern American continent has become increasingly warm and dry after the last interdecadal ***,the African continent has become increasingly warm and wet,with both Europe and most of Asia having the same *** South America and the West of Australia have experienced an opposite trend in climate,becoming increasingly cold and wet.

关键词： Global terrene Surface air temperature Precipitation Interdecadal trend turning

Relative importance of water, energy, and heterogeneity in determining regional pteridophyte and seed plant richness in china

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Journal of Systematics and Evolution 2011年第2期49卷 95-107页

作者： 1,2,3 Sheng-Bin CHEN § 1 Gao-Ming JIANG 3 Zhi-Yun OUYANG 3 Wei-Hua XU 3 Yi XIAO 1 (state key laboratory of Vegetation and Environmental Change, institute of Botany, chinese academy of sciences, beijing 100093, china) 2 (Graduate University of the chinese academy of sciences, beijing 100049, china) 3 (state key laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental sciences, chinese academy of sciences, beijing 100085, china) (state key laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing 100093 China) (Graduate University of the chinese academy of sciences Beijing 100049 China) (state key laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China)

Environmental variables, such as ambient energy, water availability, and environmental heterogeneity have been frequently proposed to account for species diversity gradients. How taxon-specific functional traits define large-scale richness gradients is a fundamental issue in understanding spatial patterns of species diversity, but has not been well documented. Using a large dataset on the regional flora from china, we examine the contrast spatial patterns and environmental determinants between pteridophytes and seed plants which differ in dispersal capacity and environmental requirements. Pteridophyte richness shows more pronounced spatial variation and stronger environmental associations than seed plant richness. Water availability generally accounts for more spatial variance in species richness of pteridophytes and seed plants than energy and heterogeneity do, especially for pteridophytes which have high dependence on moist and shady environments. Thus, pteridophyte richness is disproportionally affected by water-related variables; this in turn results in a higher proportion of pteridophytes in regional vascular plant floras (pteridophyte proportion) in wet regions. Most of the variance in seed plant richness, pteridophyte richness, and pteridophyte proportion explained by energy is included in variation that water and heterogeneity account for, indicating the redundancy of energy in the study extent. However, heterogeneity is more important for determining seed plant distributions. Pteridophyte and seed plant richness is strongly correlated, even after the environmental effects have been removed, implying functional linkages between them. Our study highlights the importance of incorporating biological traits of different taxonomic groups into the studies of macroecology and global change biology.

关键词： habitat heterogeneity pteridophytes seed plants species richness water-energy hypothesis.

Research on applying physical chaos generator to spacecraft information security

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Science china(Technological sciences) 2009年第5期52卷 1463-1470页

作者： ZHAO HePing state key laboratory of Information Security,Graduate University of chinese academy of sciences,beijing 100049,china china academy of Space Technology,beijing 100094,china state key laboratory of Information Security Graduate University of Chinese Academy of Sciences Beijing China china academy of Space Technology Beijing China

The effectiveness of a short-length message extension method based on physical chaos generator was analyzed and the entropy of the extended message was calculated in this *** analysis demon-strated that with the mentioned method the entropy of short-length messages,which are repeatedly used in spacecraft data systems,is obviously increased,and the security of transmission is enhanced as *** paper also presented an improvement of the protocol for secret key agreement presented by *** and *** of depending on characteristics of communication channel,this method takes advantage of the random data produced by physical chaos generator to preset the initial parameters of the procedure on both sides of communication,so that the procedure and quantity of cipher key can be precisely *** method can be used to cipher key management of se-cure communication between long life-span spacecraft and ground system.

关键词： physical chaos generator spacecraft information security message extension cipher key management

维普期刊数据库

Mechanical stretch induces mitochondria-dependent apoptosis in neonatal rat cardiomyocytes and G2/M accumulation in cardiac fibroblasts

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Cell Research 2004年第1期14卷 16-26页

作者： Xu Dong LIAO~(1,2), Xiao Hui WANG~1, Hai Jing JIN~1, Lan Ying CHEN~(2,*), Quan CHEN~(1,*) ~1laboratory of Apoptosis and Cancer Biology, state key laboratory of biomembrane and membrane Biotechnology, chinese academy of sciences, beijing 100080, china. ~2Cardiovascular institute and Fu Wai Hospital, Peking Union Medical College and chinese academy of Medical sciences, beijing 100037, china. laboratory of Apoptosis and Cancer Biology State Key Laboratory of Biomembrane and Membrane Biotechnology Chinese Academy of Sciences Beijing China Cardiovascular institute and Fu Wai Hospital Peking Union Medical College and Chinese Academy of Medical Sciences Beijing China

Heart remodeling is associated with the loss of cardiomyocytes and increase of fibrous tissue owing to abnormal mechanical load in a number of heart disease conditions. In present study, a well-described in vitro sustained stretch model was employed to study mechanical stretch-induced responses in both neonatal cardiomyocytes and cardiac fibroblasts. Cardiomyocytes, but not cardiac fibroblasts, underwent mitochondria-dependent apoptosis as evidenced by cytochrome c (cyto c) and Smac/DIABLO release from mitochondria into cytosol accompanied by mitochondrial membrane potential (△ψ_m) reduction, indicative of mitochondrial permeability transition pore (PTP) opening. Cyclosporin A, an inhibitor of PTP, inhibited stretch-induced cyto c release, △ψ_m reduction and apoptosis, suggesting an important role of mitochondrial PTP in stretch-induced apoptosis. The stretch also resulted in increased expression of the pro-apoptotic Bcl-2 family proteins, including Bax and Bad, in cardiomyocytes, but not in fibrobl

关键词： apoptosis mechanical stretch Bcl-2 and its family proteins mitochondria cardiomyocyte.

Progress in interspecies cloning of mammals

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Progress in Natural Science:Materials International 2004年第1期14卷 2-9页

作者： WEN Duancheng, BI Chunming and CHEN Dayuan(state key laboratory of Reproductive Biology, institute of zoology, chinese academy of sciences, beijing 100080, china) chinese Acad Sci Inst Zool State Key Lab Reprod Biol Beijing 100080 Peoples R China

Interspecies mammalian cloning can be achieved by application of two key techniques, i.e. the technique of interspecies nuclear transfer and the technique of interspecies pregnancy. The general principles, problems and possible solutions, as well as the recent advances of interspecies mammalian cloning have been summarized in this review.

关键词： interspecies cloning interspecies nuclear transfer interspecies pregnancy mammals

Functional evolutionary developmental biology (evo-devo) of morphological novelties in plants

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Journal of Systematics and Evolution 2010年第2期48卷 94-101页

作者： Jisi ZHANG Ying TIAN Li WANG Chaoying HE (state key laboratory of Systematic and Evolutionary Botany,institute of Botany,chinese academy of sciences,beijing 100093,china) (state key laboratory of Systematic and Evolutionary Botany Institute of Botany Chinese Academy of Sciences Beijing 100093 China)

The origin of morphological and ecological novelties is a long-standing problem in evolutionary *** these processes requires investigation from both the development and evolution standpoints,which promotes a new research field called "evolutionary developmental biology" (evo-devo).The fundamental mechanism for the origin of a novel structure may involve heterotopy,heterochrony,ectopic expression,or loss of an existing regulatory ***,the morphological and ecological traits controlled by the regulatory genes may be gained,lost,or regained during *** morphological novelties,for example,include homeotic alterations (related to organ identity),symmetric diversity,and changes in the size and morphology of the floral *** gains and losses can potentially arise through modification of the existing regulatory ***,we review current knowledge concerning the origin of novel floral structures,such as "evolutionary homeotic mutated flowers",floral symmetry in various plant species,and inflated calyx syndrome (ICS) within *** evo-devo of the morphological novelties is a central theme of plant evolutionary *** addition,the discussion is extended to consider agronomic or domestication-related traits,including the type,size,and morphology of fruits (berries),within Solanaceae.

关键词： biodiversity development evolution functional evo-devo heterochrony heterotopy morphological novelty

LEAFY HEAD2,which encodes a putative RNA-binding protein,regulates shoot development of rice

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Cell Research 2006年第3期16卷 267-276页

作者： Guo Sheng Xiong~(1,3) Xing Ming Hu~2 Yong Qing Jiao~1 Yan Chun Yu~1 Cheng Cai Chu~1 Jia Yang Li~1 Qian Qian~2 Yong Hong Wang~11 state key laboratory of Plant Genomics and National Center for Plant Gene Research,institute of Genetics and Developmental Biology,chinese academy of sciences,beijing 100101,china 2.state key laboratory of Rice Biology,china National Rice Research institute,chinese academy of Agricultural sciences,Hangzhou 310006,china 3 Graduate University of chinese academy of sciences,beijing 100049,china state key laboratory of Plant Genomics and National Center for Plant Gene Research Institute of Genetics and Developmental Biology Chinese Academy of Sciences Beijing China Graduate University of chinese academy of sciences Beijing China state key laboratory of Rice Biology China National Rice Research Institute Chinese Academy of Agricultural Sciences Hangzhou China

During vegetative development,higher plants continuously form new leaves in regular spatial and temporal *** with abnormal leaf developmental patterns not only provide a great insight into understanding the regulatorymechanism of plant architecture,but also enrich the ways to its modification by which crop yield could be ***,we reported the characterization of the rice leafy-head2 (lhd2) mutant that exhibits shortened plastochron,dwarfism,reduced tiller number,and failure of phase transition from vegetative to reproductive *** and histologicalstudy revealed that the rapid emergence of leaves in lhd2 was resulted from the rapid initiation ofleafprimordia whereasthe reduced tiller number was a consequence of the suppression of the tiller bud *** molecular and geneticanalysis showed that LHD2 encodes a putative RNA binding protein with 67% similarity to maize *** ofgenome-scale expression profiles between wild-type and lhd2 plants suggested that LHD2 may regulate rice shoot devel-opment through KNOXand hormone-related *** similar phenotypes caused by LHD2 mutation and the conservedexpression pattern of LHD2 indicated a conserved mechanism in controlling the temporal leaf initiation in grass.

关键词： phyllotaxy plastochron LHD2 RNA-binding protein stem elongation plant architecture Oryza sativa L