Construction of shuttle, expression vector of human tumor necrosis factor alpha (hTNF-alpha) gene and its expression in a cyanobacterium, Anabaena sp. PCC 7120

The construction of the shuttle, expression vector of human tumor necrosis factor alpha (hTNF-alpha) gene and its expression in a cyanobacterium Anabaena sp. PCC 7120 was reported. The 700-bp hTNF cDNA fragments have been recovered from plasmid pRL-rhTNF, then inserted downstream of the promoter PpsbA in the plasmid pRL439. The resultant intermediary plasmid pRL-TC has further been combined with the shuttle vector pDC-8 to get the shuttle, expression vector pDC-TNF. The expression of the rhTNF gene in Escherichia coil has been analyzed by SDS-PAGE and thin-layer scanning, and the results show that the expressed TNF protein with these two vectors is 16.9 percent (pRL-TC) and 15.0 percent (pDC-TNF) of the total proteins in the cells, respectively, while the expression level of TNF gene in plasmid pRL-rhTNF is only 11.8 percent. Combined with the participation of the conjugal and helper plasmids, pDC-TNF has been introduced into Anabaena sg PCC 7120 by triparental conjugative transfer, and the stable transgenic strains have been obtained. The existence of the introduced plasmid pDC-TNF in recombinant cyanobacterial cells has been demonstrated by the results of the agarose electrophoresis with the extracted plasmid samples and Southern blotting with alpha-(32)p labeled hTNF cDNA probes, while the expression of the hTNF gene in Anabaena sp. PCC 7120 has been confirmed by the results of Western blotting with extracted protein samples and human TNF-alpha monoclonal antibodies. The cytotoxicity assays using the mouse cancer cell line L929 proved the cytotoxicity of the TNF in the crude extracts from the transgenic cyanobacterium Anabaena sp. PCC 7120.

attB site disruption in marine Actinomyces sp M048 via DNA transformation of a site-specific integration vector

An efficient conjugation method has been developed for the marine Actinomyces sp. isolate M048 to facilitate the genetic manipulation of the chandrananimycin biosynthesis gene cluster. A phi C31-derived integration vector pIJ8600 containing oriT and attP fragments was introduced into strain M048 by bi-parental conjugation from Escherichia coli ET12567 to strain M048. Transformation efficiency was (6.38 +/- 0.41) x 10(-5) exconjugants per recipient spore. Analysis of eight exconjugants showed that the plasmid pIJ8600 was stably integrated at a single chromosomal site (attB) of the Actinomyces genome. The DNA sequence of the attB was cloned and shown to be conserved. The results of antimicrobial activity analysis indicated that the insertion of plasmid pIJ8600 seemed to affect the biosynthesis of antibiotics that could strongly inhibit the growth of E. coli and Mucor miehei (Tu284). HPLC-MS analysis of the extracts indicated that disruption of the attB site resulted in the complete abolition of chandrananimycin A-C production, proving the identity of the gene cluster. Instead of chandrananimycins, two bafilomycins were produced through disruption of the attB site from the chromosomal DNA of marine Actinomyces sp. M048.

Outer wave number spectrum and statistical distribution of apparent wave number vector

Based on the ray theory and Longuet-Higgins's linear,model of sea waves, the joint distribution of wave envelope and apparent wave number vector is established. From the joint distribution, we define a new concept, namely the outer wave number spectrum, to describe the outer characteristics of ocean waves. The analytical form of the outer wave number spectrum, the probability distributions of the apparent wave number vector and its components are then derived. The outer wave number spectrum is compared with the inner wave number spectrum for the average status of wind-wave development corresponding to a peakness factor P = 3. Discussions on the similarity and difference between the outer wave number spectrum and inner one are also presented in the paper. (C) 2002 Elsevier Science Ltd. All rights reserved.

Ship-board measurements and estimations of air-sea fluxes in the western tropical Pacific during TOGA COARE

Direct air-sea flux measurements were made on RN Kexue #1 at 40 degrees S, 156 degrees E during the Tropical Ocean Global Atmosphere (TOGA) Coupled Ocean-Atmospheric Response Experiment (COARE) Intensive Observation Period (IOP). An array of six accelerometers was used to measure the motion of the anchored ship, and a sonic anemometer and Lyman-alpha hygrometer were used to measure the turbulent wind vector and specific humidity. The contamination of the turbulent wind components by ship motion was largely removed by an improvement of a procedure due to Shao based on the acceleration signals. The scheme of the wind correction for ship motion is briefly outlined. Results are presented from data for the best wind direction relative to the ship to minimize flow distortion effects. Both the time series and the power spectra of the sonic-measured wind components show swell-induced ship motion contamination, which is largely removed by the accelerometer correction scheme, There was less contamination in the longitudinal wind component than in the vertical and transverse components. The spectral characteristics of the surface-layer turbulence properties are compared with those from previous land and ocean results, Momentum and latent heat fluxes were calculated by eddy correlation and compared to those estimated by the inertial dissipation method and the TOGA COARE bulk formula. The estimations of wind stress determined by eddy correlation are smaller than those from the TOGA COARE bulk formula, especially for higher wind speeds, while those from the bulk formula and inertial dissipation technique are generally in agreement. The estimations of latent heal flux from the three different methods are in reasonable agreement. The effect of the correction for ship motion on latent heat fluxes is not as large as on momentum fluxes.

基于状态构形矢量和状态构形矩阵的可重构模块星球机器人构形水

可重构模块星球机器人系统由母体和多个子机器人模块组成,单个模块可以独立运动和操作,多个模块可以重构组合成不同构形,模块采用非对称式轮手一体机构,具有姿态方位性和运动方向性,重构目的是组成在某种环境下更好地完成有向性运动的构形。基于此,提出矢量构形概念,将运动趋势方向和方位性融合到构形拓扑结构中。在模块矢量分析模型基础上,提出并构建状态构形矢量(State configuration vector,SCV)和状态构形矩阵(State configuration matrix,SCM),对非对称式单模块和整体构形的状态信息进行描述,同时支持预定义的数学变换操作,可以表达并触发模块的基础动作、构形重构。提出离散模块组合重构成目标构形的优化分析算法,通过实例仿真计算获得优化分析的选择结果。

VTI各向异性叠前深度偏移及速度分析

Theoretical research, laboratory test and field observation show that most of sediment rock has anisotropic features. It will produce some notable errors when applying isotropic methods such as prestack depth migration and velocity analysis to dada acquired under anisotropic condition; it also has a bad effect on geologic interpretation. Generally speaking, the vertical transverse isotropic media is a good approximation to geologic structure, thus it has an important realistic meaning for anisotropic prestack depth migration theory researching and precise complex geologic imaging if considering anisotropic effect of seismic wave propagation. There are two indispensable parts in prestack depth migration of realistic records, one is proper prestack depth migration algorithm, and the other is velocity analysis using prestack seismic data. The paper consists of the two aspects. Based on implicit finite difference research proposed by Dietrich Ristow et al （1997） about VTI media prestack depth migration, the paper proposed split-step Fourier prestack depth migration algorithm （VTISSF） and Fourier finite difference algorithm （VTIFFD） based on wave equation for VTI media, program are designed and the depth migration method are tested using synthetic model. The result shows that VTISSF is a stable algorithm, it generally gets a good result if the reflector dip is not very steep, while undermigration phenomena appeared in steep dips case; the VTIFFD algorithm bring us better result in steep dips with lower efficiency and frequency dispersion. For anisotropic prestack depth migration velocity analysis of VTI media, The paper discussed the basic hypothesis of VTI model in velocity analysis algorithm, basis of anisotropic prestack depth migration velocity analysis and travel time table calculation of VTI media in integral prestack depth migration. Then , analyzed the P-wave common imaging gather in the case of homogeneous velocity and vertically variable velocity . studied the residual correction in common imaging gather produced by media parameter error, analyzed the condition of flat event and correct depth in common imaging gather . In this case, the anisotropic model parameter vector is , is vertical velocity of a point at top surface, is vertical velocity gradient, and are anisotropic parameter. We can get vertical velocity gradient from seismic data; then the P-wave common imaging gather of VTI media whose velocity varies in vertical and horizontal direction, the relationship between media parameter and event residual time shift of common image gather are studied. We got the condition of flattening common imaging gather with correct depth. In this case the anisotropic model parameter vector is , is velocity gradient in horizontal direction. As a result, the vertical velocity grads can be decided uniquely, but horizontal velocity grads and anisotropic parameter can’t be distinguished if no priori information available, our method is to supply parameter by velocity scanning; then, as soon as is supplied we can get another four parameters of VTI media from seismic data. Based on above analysis, the paper discussed the feasibility of migration velocity analysis in vertically and horizontally varied VTI media, synthetic record of three models are used to test the velocity analysis method . Firstly, anisotropic velocity analysis test is done using a simple model with one block, then we used a model with multiple blocks, thirdly, we analyzed the anisotropic velocity using a part of Marmousi model. The model results show that this velocity analysis method is feasible and correct.

层状反倾向结构岩质边坡变形机理及稳定性研究

Toppling is a major failure model in anti-dip layered rock slopes. Because of the limited by testing means and experimental apparatus, present research on the deformation mechanism and stability analysis are mainly focus on the 2-Dimensional deformation, and the research really based on 3-Dimension is still limited. Therefore, based on the present research station, the article rely on the important hydroelectric project of typical anti-dip layered rock slopes -- The left bank slope of Long-tan hydropower-station in Guang Xi, China, and focused on the influencing factors, deformation mechanism and stability analysis of anti-dip layered rock slopes, three problems as follows are researched in this paper. (1) Deformation influencing factor analysis on ant-dip layered rock slopes Three influencing factors are included: geological factor, engineering factor and environmental factor. It is concluded that the toppling deformation of anti-dip layered rock slopes are more sensitive to geological and engineering factors, but less sensitive to environmental factor. In addition, the sensitivity of various factors to the rock toppling deformation is also arranged sequentially as follows: construction, gravitation, rainfall (underground water) and rock structure intensity, etc. (2) 3D deformation study on the anti-dip layered toppling rock slopes Used 3D Distinct Element Method (3DEC) analyzed the 3D deformation characteristic of anti-dip layered rock slops. It can be seen that the toppling characteristics are obvious when the inter-angle between slope direction and layer striking direction is under 20o, when the inter-angle is over 20o and equal or less than 40o，the toppling deformation characteristics decrease sharply with increase of inter-angle, when the inter-angle is over 40o , the slope deformation is not controlled by joints but influenced by other failure mode. Therefore, in order to quantify the toppling characteristics, a differential value of displacement vector angle between layered rock slope and block rock slope is proposed as a key index to distinguish failure model for anti-dip layered rock slopes, and it was applied to study the toppling of the rock slopes at Guangxi Long-tan hydropower station, China. The results indicated that the index was effective and instructive for analyzing the anti-dip layered rock slopes. (3) Stability analysis methods Because of the imperfection of some present slope analysis methods, based on slope failure mode and those three influencing factors, “slope stability entropy” method is defined in this paper, which makes good use of the sensitivity of relational matrix to influencing factors on slope stability and the qualification characteristics for information entropy to the irregularity of slope deformation. By this method, not only the randomness of geologic body on the base of dynamic analysis of slope failure mode is fully concerned, but also it makes the analysis time-saving and simple. Finally, the research findings were used to the engineering example successfully, and rational conclusion has been obtained.

用宽频带远震体波波形研究中国及邻近地区地壳构造及地质意义初探

The theory and approach of the broadband teleseismic body waveform inversion are expatiated in this paper, and the defining the crust structure's methods are developed. Based on the teleseismic P-wave data, the theoretic image of the P-wave radical component is calculated via the convolution of the teleseismic P-wave vertical component and the transform function, and thereby a P-wavefrom inversion method is built. The applied results show the approach effective, stable and its resolution high. The exact and reliable teleseismic P waveforms recorded by CDSN and IRIS and its geodynamics are utilized to obtain China and its vicinage lithospheric transfer functions, this region ithospheric structure is inverted through the inversion of reliable transfer functions, the new knowledge about the deep structure of China and its vicinage is obtained, and the reliable seismological evidence is provided to reveal the geodynamic evolution processes and set up the continental collisional theory. The major studies are as follows: Two important methods to study crustal and upper mantle structure -- body wave travel-time inversion and waveform modeling are reviewed systematically. Based on ray theory, travel-time inversion is characterized by simplicity, crustal and upper mantle velocity model can be obtained by using 1-D travel-time inversion preliminary, which introduces the reference model for studying focal location, focal mechanism, and fine structure of crustal and upper mantle. The large-scale lateral inhomogeneity of crustal and upper mantle can be obtained by three-dimensional t ravel-time seismic tomography. Based on elastic dynamics, through the fitting between theoretical seismogram and observed seismogram, waveform modeling can interpret the detail waveform and further uncover one-dimensional fine structure and lateral variation of crustal and upper mantle, especially the media characteristics of singular zones of ray. Whatever travel-time inversion and waveform modeling is supposed under certain approximate conditions, with respective advantages and disadvantages, and provide convincing structure information for elucidating physical and chemical features and geodynamic processes of crustal and upper mantle. Because the direct wave, surface wave, and refraction wave have lower resolution in investigating seismic velocity transitional zone, which is inadequate to study seismic discontinuities. On the contrary, both the converse and reflected wave, which sample the discontinuities directly, must be carefully picked up from seismogram to constrain the velocity transitional zones. Not only can the converse wave and reflected wave study the crustal structure, but also investigate the upper mantle discontinuities. There are a number of global and regional seismic discontinuities in the crustal and upper mantle, which plays a significant role in understanding physical and chemical properties and geodynamic processes of crustal and upper mantle. The broadband teleseismic P waveform inversion is studied particularly. The teleseismic P waveforms contain a lot of information related to source time function, near-source structure, propagation effect through the mantle, receiver structure, and instrument response, receiver function is isolated form teleseismic P waveform through the vector rotation of horizontal components into ray direction and the deconvolution of vertical component from the radial and tangential components of ground motion, the resulting time series is dominated by local receiver structure effect, and is hardly irrelevant to source and deep mantle effects. Receiver function is horizontal response, which eliminate multiple P wave reflection and retain direct wave and P-S converted waves, and is sensitive to the vertical variation of S wave velocity. Velocity structure beneath a seismic station has different response to radial and vertical component of an accident teleseismic P wave. To avoid the limits caused by a simplified assumption on the vertical response, the receiver function method is mended. In the frequency domain, the transfer function is showed by the ratio of radical response and vertical response of the media to P wave. In the time domain, the radial synthetic waveform can be obtained by the convolution of the transfer function with the vertical wave. In order to overcome the numerical instability, generalized reflection and transmission coefficient matrix method is applied to calculate the synthetic waveform so that all multi-reflection and phase conversion response can be included. A new inversion method, VFSA-LM method, is used in this study, which successfully combines very fast simulated annealing method (VFSA) with damped least square inversion method (LM). Synthetic waveform inversion test confirms its effectiveness and efficiency. Broadband teleseismic P waveform inversion is applied in lithospheric velocity study of China and its vicinage. According to the data of high quality CDSN and IRIS, we obtained an outline map showing the distribution of Asian continental crustal thickness. Based on these results gained, the features of distribution of the crustal thickness and outline of crustal structure under the Asian continent have been analyzed and studied. Finally, this paper advances the principal characteristics of the Asian continental crust. There exist four vast areas of relatively minor variations in the crustal thickness, namely, northern, eastern southern and central areas of Asian crust. As a byproduct, the earthquake location is discussed, Which is a basic issue in seismology. Because of the strong trade-off between the assumed initial time and focal depth and the nonlinear of the inversion problems, this issue is not settled at all. Aimed at the problem, a new earthquake location method named SAMS method is presented, In which, the objective function is the absolute value of the remnants of travel times together with the arrival times and use the Fast Simulated Annealing method is used to inverse. Applied in the Chi-Chi event relocation of Taiwan occurred on Sep 21, 2000, the results show that the SAMS method not only can reduce the effects of the trade-off between the initial time and focal depth, but can get better stability and resolving power. At the end of the paper, the inverse Q filtering method for compensating attenuation and frequency dispersion used in the seismic section of depth domain is discussed. According to the forward and inverse results of synthesized seismic records, our Q filtrating operator of the depth domain is consistent with the seismic laws in the absorbing media, which not only considers the effect of the media absorbing of the waves, but also fits the deformation laws, namely the frequency dispersion of the body wave. Two post stacked profiles about 60KM, a neritic area of China processed, the result shows that after the forward Q filtering of the depth domain, the wide of the wavelet of the middle and deep layers is compressed, the resolution and signal noise ratio are enhanced, and the primary sharp and energy distribution of the profile are retained.

新疆自然区划单元土地利用/覆盖分布图谱研究

Under the direction of Geo-informatic Tupu theory, based on comprehensive natural division in Xinjiang and 1:100000 land use and land cover vector data in 2000 from resource and environment database of CAS, the paper gave out some distribution Tupu of land resource types in different regions of Xinjiang. GIS tools such as ARCTOOLS and ARCV1EW were used to clip the unit of each natural division. Some useful conclusions were established. Then the lower reaches of Tarim River were selected as typical area to analyze the ecological environment evolvement from 2000 to 2004 since the beginning of ecological water delivering. The comprehensive space-time analysis provided a method to monitor the effect dynamically. The main contents of the thesis are listed as follows: (1) Similarities and differences between North Xinjiang and South Xinjiang, 6 second-classified regions and 37 third-classified regions. The conclusion of each region emphasized the percentage of area of main land types, characteristic description and distribution of cultivated land > woodlands grassland-, water area^ urban and rural land and unused land. (2) Thematic Tupu of each region. It concluded artificial oasis Tupu, the proportion between dense-grass% moderate-grass and sparse-grass, pattern of land resources and the land use degree. The artificial oasis mean cultivated land^ woodland^ urban & rural land and other construction land. The proportion of grassland disclosed the quality of all grassland and showed the development of them. Pattern of land resources and the land use degree gave out the detailed development direction and development degree of each region. (3) Ecological environment evolvement of the lower reaches of Tarim River. The effects of each ecological water delivering were compared.

不同学习策略对改变学生物理要领错误的影响

In the field of misconceptions research, previous research was focused mainly on the effect of naive concepts on the learning of scientific concept. In this study, from the viewpoint of declarative and procedural knowledge, conceptual errors on Newtonian mechanics were studied comparatively between high-performance and low-performance students. Furthermore, the effects of self-explain learning strategies and reflective learning on the change of subjects' conceptual errors were explored. The result of experiments indicated: 1. There was significant difference in the number of conceptual errors of declarative and procedural knowledge between high-performance students and low-performance students. And Low-performance students made more conceptual errors of procedural knowledge than that of declarative knowledge. For high-performance students, there was no distinct difference between these two kinds of errors. 2. In the distribution of conceptual errors, most errors of declarative knowledge were mainly focused on the understanding of concepts of friction and acceleration. The errors of procedure knowledge most errors concentrated on the judgment of vector direction and the conceptual understanding. 3. Compared with high-performance students, the representation of conceptual declarative knowledge of low-performance students is less complex, more concrete and context bound. 4. The comparative analysis of problem-solving strategies showed: high-performance students preferred to apply analytic strategy, solving problems based on physical concepts and principles; low-performance students preferred to use context strategy, solving problem according to the literal meaning of problems, subjective and groundless presumption and wrong concepts and principles. 5. Self-explain strategies can help students correct their conceptual errors effectively. Reflective learning could help students to correct the concept errors in some degree, but the distinct effect was not observed.

Shaping Inputs to Reduce Vibration: A Vector Diagram Approach

This paper describes a method for limiting vibration in flexible systems by shaping the system inputs. Unlike most previous attempts at input shaping, this method does not require an extensive system model or lengthy numerical computation; only knowledge of the system natural frequency and damping ratio are required. The effectiveness of this method when there are errors in the system model is explored and quantified. An algorithm is presented which, given an upper bound on acceptable residual vibration amplitude, determines a shaping strategy that is insensitive to errors in the estimated natural frequency. A procedure for shaping inputs to systems with input constraints is outlined. The shaping method is evaluated by dynamic simulations and hardware experiments.

Multi-Scale Vector-Ridge-Detection for Perceptual Organization Without Edges

We present a novel ridge detector that finds ridges on vector fields. It is designed to automatically find the right scale of a ridge even in the presence of noise, multiple steps and narrow valleys. One of the key features of such ridge detector is that it has a zero response at discontinuities. The ridge detector can be applied to scalar and vector quantities such as color. We also present a parallel perceptual organization scheme based on such ridge detector that works without edges; in addition to perceptual groups, the scheme computes potential focus of attention points at which to direct future processing. The relation to human perception and several theoretical findings supporting the scheme are presented. We also show results of a Connection Machine implementation of the scheme for perceptual organization (without edges) using color.

Estimation of Pose and Illuminant Direction for Face Processing

In this paper three problems related to the analysis of facial images are addressed: the illuminant direction, the compensation of illumination effects and, finally, the recovery of the pose of the face, restricted to in-depth rotations. The solutions proposed for these problems rely on the use of computer graphics techniques to provide images of faces under different illumination and pose, starting from a database of frontal views under frontal illumination.

An Analog VLSI Chip for Estimating the Focus of Expansion

For applications involving the control of moving vehicles, the recovery of relative motion between a camera and its environment is of high utility. This thesis describes the design and testing of a real-time analog VLSI chip which estimates the focus of expansion (FOE) from measured time-varying images. Our approach assumes a camera moving through a fixed world with translational velocity; the FOE is the projection of the translation vector onto the image plane. This location is the point towards which the camera is moving, and other points appear to be expanding outward from. By way of the camera imaging parameters, the location of the FOE gives the direction of 3-D translation. The algorithm we use for estimating the FOE minimizes the sum of squares of the differences at every pixel between the observed time variation of brightness and the predicted variation given the assumed position of the FOE. This minimization is not straightforward, because the relationship between the brightness derivatives depends on the unknown distance to the surface being imaged. However, image points where brightness is instantaneously constant play a critical role. Ideally, the FOE would be at the intersection of the tangents to the iso-brightness contours at these "stationary" points. In practice, brightness derivatives are hard to estimate accurately given that the image is quite noisy. Reliable results can nevertheless be obtained if the image contains many stationary points and the point is found that minimizes the sum of squares of the perpendicular distances from the tangents at the stationary points. The FOE chip calculates the gradient of this least-squares minimization sum, and the estimation is performed by closing a feedback loop around it. The chip has been implemented using an embedded CCD imager for image acquisition and a row-parallel processing scheme. A 64 x 64 version was fabricated in a 2um CCD/ BiCMOS process through MOSIS with a design goal of 200 mW of on-chip power, a top frame rate of 1000 frames/second, and a basic accuracy of 5%. A complete experimental system which estimates the FOE in real time using real motion and image scenes is demonstrated.

Time-Frequency Representations for Speech Signals

This work addresses two related questions. The first question is what joint time-frequency energy representations are most appropriate for auditory signals, in particular, for speech signals in sonorant regions. The quadratic transforms of the signal are examined, a large class that includes, for example, the spectrograms and the Wigner distribution. Quasi-stationarity is not assumed, since this would neglect dynamic regions. A set of desired properties is proposed for the representation: (1) shift-invariance, (2) positivity, (3) superposition, (4) locality, and (5) smoothness. Several relations among these properties are proved: shift-invariance and positivity imply the transform is a superposition of spectrograms; positivity and superposition are equivalent conditions when the transform is real; positivity limits the simultaneous time and frequency resolution (locality) possible for the transform, defining an uncertainty relation for joint time-frequency energy representations; and locality and smoothness tradeoff by the 2-D generalization of the classical uncertainty relation. The transform that best meets these criteria is derived, which consists of two-dimensionally smoothed Wigner distributions with (possibly oriented) 2-D guassian kernels. These transforms are then related to time-frequency filtering, a method for estimating the time-varying 'transfer function' of the vocal tract, which is somewhat analogous to ceptstral filtering generalized to the time-varying case. Natural speech examples are provided. The second question addressed is how to obtain a rich, symbolic description of the phonetically relevant features in these time-frequency energy surfaces, the so-called schematic spectrogram. Time-frequency ridges, the 2-D analog of spectral peaks, are one feature that is proposed. If non-oriented kernels are used for the energy representation, then the ridge tops can be identified, with zero-crossings in the inner product of the gradient vector and the direction of greatest downward curvature. If oriented kernels are used, the method can be generalized to give better orientation selectivity (e.g., at intersecting ridges) at the cost of poorer time-frequency locality. Many speech examples are given showing the performance for some traditionally difficult cases: semi-vowels and glides, nasalized vowels, consonant-vowel transitions, female speech, and imperfect transmission channels.