检索结果-南通市图书馆

Detection of bursts in neuronal spike trains by the mean inter-spike interval method

在线全文

学校读者我要写书评

暂无评论

Progress in Natural science:Materials International 2009年第2期19卷 229-235页

作者： Lin Chena,b,Yong Deng c,Weihua Luo a,Zhen Wang a,Shaoqun Zenga,a Hubei Bioinformatics and Molecular imaging Key Laboratory,Huazhong university of science and Technology,Wuhan 4.0074.China b College of Mechanical Engineering,Guangxi university,Nanning,530004.China c College of Optoelectronic science of Engineering,Huazhong university of science and Technology,Wuhan 4.0074.China Hubei Bioinformatics and Molecular imaging Key Laboratory Huazhong University of Science and Technology Wuhan 430074 China College of Mechanical Engineering Guangxi University Nanning 530004 China College of Optoelectronic science of Engineering Huazhong University of Science and Technology Wuhan 430074 China

Bursts are electrical spikes firing with a high frequency,which are the most important property in synaptic plasticity and information processing in the central nervous system. However,bursts are difficult to identify because bursting activities or patterns vary with phys-iological conditions or external stimuli. In this paper,a simple method automatically to detect bursts in spike trains is described. This method auto-adaptively sets a parameter (mean inter-spike interval) according to intrinsic properties of the detected burst spike trains,without any arbitrary choices or any operator judgment. When the mean value of several successive inter-spike intervals is not larger than the parameter,a burst is identified. By this method,bursts can be automatically extracted from different bursting patterns of cultured neurons on multi-electrode arrays,as accurately as by visual inspection. Furthermore,significant changes of burst variables caused by electrical stimulus have been found in spontaneous activity of neuronal network. These suggest that the mean inter-spike interval method is robust for detecting changes in burst patterns and characteristics induced by environmental alterations.

关键词： Inter-spike interval Bursts Spike trains Multi-electrode arrays

Use of Linear Spectral Mixture Model to Estimate Rice Planted Area Based on MODIS Data

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Rice science 2008年第2期15卷 131-136页

作者： WANG Lei Satoshi UCHID center for science and Technology Information China National Rice Research Institute Hangzhou 310006 China Development research Division Japan International Research Center for Agricultural Sciences Tsukuba Ibaraki 305-8686 Japan

MODIS （Moderate Resolution imaging Spectroradiometer） is a key instrument aboard the Terra （EOS AM） and Aqua （EOS PM） satellites. Linear spectral mixture models are applied to MOIDS data for the sub-pixel classification of land covers. Shaoxing county of Zhejiang Province in China was chosen to be the study site and early rice was selected as the study crop. The derived proportions of land covers from MODIS pixel using linear spectral mixture models were compared with unsupervised classification derived from TM data acquired on the same day, which implies that MODIS data could be used as satellite data source for rice cultivation area estimation, possibly rice growth monitoring and yield forecasting on the regional scale.

关键词： rice planted area Moderate Resolution imaging Spectroradiometer Thematic Mapper data mixed pixel linear spectral mixture model

Requirement of PSD-95 for dopamine D1 receptor modulating glutamate NR1a/NR2B receptor function

在线全文

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2007年第6期28卷 756-762页

作者： Wei-hua GU~2,Shen YANG~2,Wei-xing SHI~(2,3,4.,Guo-zhang JIN~2,Xue-chu ZHEN~(2,4.~2 Department of Pharmacology,State Key Laboratory of Drug research,Shanghai Institute of Materia Medica,Shanghai Institutes ofBiological sciences,Chinese Academy of sciences,Shanghai 201203,China ~3 Neuropsychopharmacological research Unit,Department ofPsychiatry,Yale {4. School of Medicine,New Haven CT 06511,usa Department of Pharmacology State Key Laboratory of Drug Research Shanghai Institute of Materia Medica Shanghai Institutes of Biological Sciences Chinese Academy of Sciences Shanghai China Department of Psychiatry Neuropsychopharmacological Research Unit Yale University School of Medicine New Haven USA

Aim:To elucidate the role of scaffold protein postsynaptic density （PSD）-95 inthe dopamine D1receptor （D1R）-modulated NR1a/NR2B receptor ***:The human embryonic kidney 293 cells expressing D1R （tagged with theenhanced yellow fluorescent protein） and NR1a/NR2B with or without co-expres-sion of PSD-95 were used in the *** Ca2+influx measured by imagingtechnique was employed to monitor N-methyl-D-aspartic acid receptors （NMDAR）***:The application of dopamine （DA,100 μmol/L） did not alterglutamate/glycine （Glu/Gly）-induced NMDAR-mediated Ca2+influx in cells onlyexpressing the D1R/NR1a/NR2B ***,DA increased Glu/Gly-induced Ca2+influx in a concentration-dependent manner while the cells wereco-expressed with PSD-95.D1R-stimulated Ca2+influx was inhibited by a selectiveD1R antagonist ***,pre-incubation with either the proteinkinase A （PKA） inhibitor H89,or the protein kinase C （PKC） inhibitor chelerythrineattenuated D1R-enhanced Ca2+influx induced by the N-methyl-D-aspartic acid（NMDA） *** results clearly indicate that D1R-modulated NR1a/NR2Breceptor function depends on PSD-95 and is subjected to the regulation of PKAand ***:The present study provides the first evidence that PSD-95is essential in D1R-regulated NR1a/NR2B receptor function.

关键词： D1 dopamine receptor NMDA PSD-95 signal transduction calcium

Phase Relations in TiAl+Nb System

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials science & Technology 1994年第5期10卷 359-366页

作者： Jingguo WANG Guoliang CHEN and Zuqing SUN (State Key Lab. for Advanced Metal Materials, university of science and Technology Beijing, Beijing, 100083, China)Hengqiang YE (Lab. of Atomic imaging of Solids, Institute of Metal research, Academia Sinica, Sh Univ of science and Technology Beijing China

The microstructures and phases of ternary TiAl+Nb alloys containing 50-60 at.-%Al, 0-21 at.-%Nb have been studied using transmission electron microscopy (TEM) and X-ray powder diffraction. The phases present in the alloys and their distribution were found to be a sensitive function of composition. The phase relations between γ-TiAl and γ1 (a new ordered ternary intermetallic compound based on γ-TiAl) were determined. Essentially single γ phase was determined for alloys with relativety low Nb content (≤10 at.-%Nb). the γ1 phase was determined to exist in the composition range containing higher Nb contents (15-21 at.-%Nb). Between γ and γ1 phases, with intermediate Nb contents there is a transitional phase γ1 (a superstructure of γ-TiAl). As for the influence of Al concentration on the phase relations. the γ1 phase was inclined to form in the alloys with relatively high Al contents. The ordering transformation of γ, to γ1 is a continuous ordering process and the transition may be second order.

关键词： TiAl nm PA Phase Relations in TiAl+Nb System Chen

Acronym Extraction Using SVM with Uneven Margins

在线全文

学校读者我要写书评

暂无评论

Acronym Extraction Using SVM with Uneven Margins

Status and Issues of Digital City Development in China:Findings from a Survey of 30 Cities

2010 IEEE 2nd Symposium on Web Society

作者： Weijian Ni Baidu Corporation Jun Xu Microsoft research Asia Yalou Huang Nankai university Tong Liu Shandong university of science and Technology Jianye Ge university of North texas

＜正＞Extracting acronyms and their expansions from plain text is an important problem in text mining. Previous research shows that the problem can be solved via machine learning *** is, converting the problem of acronym extraction to binary *** investigate the classification problem and find that the classes are highly unbalanced（the positive instances are very rare compared to negative ones）.So we try to tackle the problem using an uneven margin classifier - SVM with Uneven *** results showed that our approach can get better results than baseline methods of using heuristic rules and conventional SVM models. Experimental results also showed how uneven margins classifier made the tradeoff between the precision and recall of extraction.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Status and Issues of Digital City Development in China:Findi...

A Fast Algorithm for Phase Grating Preparation by Real Space Method

The Sixth World Congress on Computational Mechanics in Conjunction with the Second Asian-Pacific Congress on Computational MechanicsⅠ

作者： Junqing Zhou~(1*), Cheng Wang~1, Ming Zhang~2 1 Digital Engineering research. center, Huazhong university of science & Technology, 1037, Luo Yu Road, Wuhan, 4.0074.China 2 Department of Landscape Architecture & Urban Planning, {4. A&M university, Langford A314. College Station, TX 7784., usa

China’s approval in 2001 of its Tenth Five-Year Plan for national economic development injected a large sum of investments to the application of information technologies. Many Chinese cities have taken the opportunity to construct digital cities as part of their urban development policies. By the end of 2002, 64.cities had had their plans of digital city construction formally approved by the Provincial or the Central government, with a total investment of over 75 billion U.S. dollars. What is the state of the practice in China’s digital city development? How can the strength and weakness of the digital city projects be evaluated? How much regional variations in digital capacities are there among cities in different provinces and what factors may account for the variations? How effective is digital city construction as a policy to stimulate economic development and to improve city management and services? How does the new process of informationalization in digital cities interact with the traditional process of urbanization in physical cities? What are the implications of the interaction for urban planning, land and resources management, and urban policy making? This paper reports a study addressing these questions. The study was based on a survey of 30 Chinese cities where there were established digital city programs. These cities are spread out in 20 provinces across the nation and represent a full range of large, medium, and small-sized urban areas. Combining data collected from National Statistical Bureau, Central and Provincial Governmental agencies, and local cities, the study developed an indexing system to evaluate digital city development in the 30 cities. Development of the index incorporates 72 urban indicators in four categories: urban infrastructure, economic eanacitv, information canacitv, and sustainabilitv.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Journal of Materials science & Technology 2001年第2期17卷 240-242页

作者： Qiuxiang LIU and Yuanming WANG Laboratory of Atomic imaging of Solids, Institute of Metal research, Chinese Academy of sciences, Shengyang 110015, China Qibin YANG and Xiaohong YAN Institute of Modern Physics, Xiangtan university, Xiangtan 4.1105, China Lab. of Atomic imaging of Solids Inst. of Metal Res. Chinese Acad. of Sci. Shenyang 110015 China

Making use of this expression to calculate the phase grating in high resolution image simulation can greatly reduce the calculating time. In this paper, the derivation of the expression is introduced, and then the computer routine is explained in details. Finally the potential projection map of Mg4.Rh7 along [001] direction is shown as an illustration. All operations are carried out in real space, so we call the calculation method as the real space method.

关键词： A Fast Algorithm for Phase Grating Preparation by Real Space Method

EFFECT OF HYDROGENATION ON THE MICROSTRRUCTURE OFTi-24.l-14.b-3V-0.5Mo ALLOY

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 1999年第6期12卷 0-0,0-0+0-0页

作者： L. Dong L.G. Zhou H. Ding and C.B. Zhang(Laboratory of Atomic imaging of Solids, Institute of Metal research, The Chinese Academy of sciences,Shenyang 110015, China)(Departmeot of Material science, Northeastern {4., Shenyang 110006, China)

The ebct of hydrogenation-dehydrogenation on the microstructure of forping Ti-24.l14.b-3V-0.5MO alloy was investigated by TEM and X-ray ddection. The resultsshowed that the microstructure consists of O and B2 phases as received materials, and tmoprmation of B2 phase to O phase can be eNctively promoted 6y hydrogenation. The lamellate γ hydride was found in O phase with more hydmpen content, and this γ hydride could be decomposed by dehydmpenation treatment. The sole fine Ophase could be obtained 6y hydmpenation-dehydmpenation treatment, and two possible mechanisms for the microstructure improvetnent have been discussed on the basis of experimental results.

关键词： Ti_3Al-based alloy hydrogen treatment microstructure

Processing Pisum sativum seed storage protein precursors in vitro

在线全文

学校读者我要写书评

暂无评论

Cell research 1990年第2期1卷 153-162页

作者： C DOMONEY R CASEY TC HALL Shanghai Institute of Plant Physiology Academia Sinica Shanghai China John Innes Institute and AFRC Institute of Plant science research Norwich U.K. Department of Biology Texas A & M University College Station Texas U.S.A.

The profile of polypeptides separated by SDS-PAGE from seed of major crop species such as pea (Pisum sativum) is complex, resulting from cleavage (processing) of precursors expressed from multiple copies of genes encoding vicilin and legumin, the major storage globulins. Translation in vitro of mRNAs hybridselected from mid-maturation pea seed RNAs by defined vicilin and legumin cDNA clones provided precursor molecules that were cleaved in vitro by a cell-free protease extract obtained from similar stage seed; the derived polypeptides were of comparable sizes to those observed in vivo. The feasibility of transcribing mRNA in vitro from a cDNA clone and cleavage in vitro of the derived translation products was established for a legumin clone,providing a method for determining polypeptide products of an expressed sequence. This approach will also be useful for characterising cleavage site requirements since modifications an readily be introduced at the DNA level.

关键词： Legumin Pisum Processing Storage protein precursors Vicilin.