Constitutive expression of thymidylate synthase from LCDV-C induces a transformed phenotype in fish cells

Thymidylate synthase (TS), an essential enzyme in DNA synthesis and repair, plays a key role in the events of cell cycle regulation and tumor formation. Here, an investigation was presented about subcellular location and biological function of viral TS from lymphocystis disease virus from China (LCDV-C) in fish cells. Fluorescence microscopy revealed that LCDV-C TS was predominantly localized in the cytoplasm in fish cells. Cell cycle analysis demonstrated that LCDV-C TS promoted cell cycle progression into S and G2/M phase in the constitutive expressed cells. As a result, the cells have a faster growth rate compared with the control cells as revealed by cell growth curves. For foci assay, the TS-expressed cells gave rise to foci 4-5 weeks after incubation. Microscopic examination of the TS-induced foci revealed multilayered growth and crisscross morphology characteristic of transformed cells. Moreover, LCDV-C TS predisposed the transfected cells to acquire an anchorage-independent phenotype and could grow in 0.3% soft agar. So the data reveal LCDV-C TS is sufficient to induce a transformed phenotype in fish cells in vitro and exhibits its potential ability in cell transformation. To our knowledge, it is the first report on viral TS sequences associated with transforming activity. (C) 2007 Elsevier Inc. All rights reserved.

Two unisexual artificial polyploid clones constructed by genome addition of common carp (Cyprinus carp) and crucian carp (Carassius auratus)

A polyploid hybrid fish with natural gynogenesis can prevent segregation and maintain their hybrid vigor in their progenies. Supposing the reproduction mode of induced polyploid fish being natural gynogenesis, allopolyploid hybrid between common carp and crucian carp into allopolyploid was performed. The purpose of this paper is to describe a lineage from sexual diploid carp transforming into allotriploid and allotetraploid unisexual clones by genome addition. The diploid hybrid between common carp and crucian carp reproduces an unreduced nucleus consisting of two parental genomes. This unreduced female pronucleus will fuse with male pronucleus and form allotriploid zygote after penetration of related species sperms. Allotriploid embryos grow normally, and part of female allotriploid can produce unreduced mature ova with three genomes. Mature ova of most allotriploid females are provided with natural gynogenetic trait and their nuclei do not fuse with any entrance sperm. All female offspring are produced by gynogenesis of allotriploid egg under activation of penetrating sperms. These offspring maintain morphological traits of their allotriploid maternal and form an allotetraploid unisexual clone by gynogenetic reproduction mode. However, female nuclei of rare allotriploid female can fuse with penetrating male pronuclei and result in the appearance of allotetraploid individuals by means of genome addition. All allotetraploid females can reproduce unreduced mature eggs containing four genomes. Therefore, mature eggs of allotetraploid maintain gynogenetic trait and allotetraploid unisexual clone is produced under activation of related species sperms.

Atomic configurations of dislocation core and twin boundaries in 3C-SiC studied by high-resolution electron microscopy

The defects in 3C-SiC film grown on (001) plane of Si substrate were studied using a 200 kV high-resolution electron microscope with point resolution of 0.2 nm. A posterior image processing technique, the image deconvolution, was utilized in combination with the image contrast analysis to distinguish atoms of Si from C distant from each other by 0.109 nm in the [110] projected image. The principle of the image processing technique utilized and the related image contrast theory is briefly presented. The procedures of transforming an experimental image that does not reflect the crystal structure intuitively into the structure map and of identifying Si and C atoms from the map are described. The atomic configurations for a 30 degrees partial dislocation and a microtwin have been derived at atomic level. It has been determined that the 30 degrees partial dislocation terminates in C atom and the segment of microtwin is sandwiched between two 180 degrees rotation twins. The corresponding stacking sequences are derived and atomic models are constructed according to the restored structure maps for both the 30 degrees partial dislocation and microtwin. Images were simulated based on the two models to affirm the above-mentioned results.

High dimensional imagery geometry and it's applications

Because of information digitalization and the correspondence of digits and the coordinates, Information Science and high-dimensional space have consanguineous relations. With the transforming from the information issues to the point analysis in high-dimensional space, we proposed a novel computational theory, named High dimensional imagery geometry (HDIG). Some computational algorithms of HDIG have been realized using software, and how to combine with groups of simple operators in some 2D planes to implement the geometrical computations in high-dimensional space is demonstrated in this paper. As the applications, two kinds of experiments of HDIG, which are blurred image restoration and pattern recognition ones, are given, and the results are satisfying.

Conditions for the local manipulation of all bipartite Gaussian states

We provide a general, necessary, and sufficient condition for the possibility of transforming a mixed bipartite Gaussian state with arbitrarily many modes to another one under arbitrary local Gaussian channels, which do not include classical communication. Moreover, by means of this condition we present a necessary criterion that can be used to check the possibility of a state transformation between two mixed Gaussian states. At the same time, we prove that our criterion can be reduced to the Eisert-Plenio criterion when the mode number is chosen as 1 per side.

针对C语言的自动微分系统及其应用

采用切线性模式和代码转换策略,开发了C语言自动微分转换系统(DTC),用于牛顿法求解非线性方程中Jacobi矩阵—向量乘积计算。介绍系统计算模型、功能、特色,并讨论系统的设计与实现技术,包括编译技术、微分代码转换及输入/输出(I/O)相关分析。最后给出了几个具有说服力的测试与应用。

认证测试的一个扩展

对Guttman等人提出的3种测试中的输入测试（incomingtest）进行扩展，使其能够用来分析使用签名和验证的协议，如CCITTX．509协议等．使用扩展后的输入测试来分析CCITTX．509协议的正确性，发现它的不足之处．

On the soft wall guiding potentials in realistic quantum waveguides

A transfer matrix method is presented for the study of electron conduction in a quantum waveguide with soft wall lateral confinement. By transforming the two-dimensional Schrodinger equation into a set of second order ordinary differential equations, the total transfer matrix is obtained and the scattering probability amplitudes are calculated. The proposed method is applied to the evaluation of the electron transmission in two types of cavity structure with finite-height square-well confinement. The results obtained by our method, which are found to be in excellent agreement with those from another transfer matrix method, suggest that the infinite square-well potential is a good approximation to finite-height square-well confinement for electrons propagating in the ground transverse mode, but softening of the walls has an obvious effect on the electron transmission and mode-mixing for propagating in the excited transverse mode. (C) 1996 American Institute of Physics.

自动微分程序设计及在PETSc中的集成与应用

大规模科学计算已经广泛应用在气象、海洋、化学、生物医药、电子工程等领域。科学计算软件的开发是科学计算的关键环节。开发一个具有良好可靠性的计算工具，并与大型计算工具箱集成而完成大规模、复杂实际问题的计算，具有重要意义。 PETSc（Portable, Extensible Toolkit for Scientific Computation）是国际流行的科学计算工具箱，它可用于偏微分方程的求解及相关的高性能计算问题。本文分析了PETSc的主要功能、结构与特色，并剖析了其核心组件，包括向量、矩阵、线性方程组求解器KSP、非线性求解器SNES等。 自动微分是计算函数导数的重要方法，它可以应用在最优化问题的实际计算中。在PETSc中提供了ADIC、ADIFOR等自动微分软件包的接口。本文分析了自动微分计算函数一阶导数的切线性模式与伴随模式的基本原理，介绍了现有的自动微分软件的情况，特别是ADIC的开发及其与PETSc的接口。 DTC（Differentiation Transforming System in C）是针对C语言自动微分工具，用于生成切线性模式。DTC生成的切线性代码可用于计算雅可比矩阵-向量乘积等。本文详细介绍了DTC系统的设计及关键技术，包括编译技术、输入/输出（IO）相关分析等。针对PETSc的复杂数据结构，开发了DTC与PETSc的接口，将两者集成，并应用在求解二维全球正压大气浅水波方程中。最后给出了DTC系统的相关测试结果。

Solving MIN UR problem by triangle evolution algorithm with archiving and niche techniques

In this paper, as an extension of minimum unsatisfied linear relations problem (MIN ULR), the minimum unsatisfied relations (MIN UR) problem is investigated. A triangle evolution algorithm with archiving and niche techniques is proposed for MIN UR problem. Different with algorithms in literature, it solves MIN problem directly, rather than transforming it into many sub-problems. The proposed algorithm is also applicable for the special case of MIN UR, in which it involves some mandatory relations. Numerical results show that the algorithm is effective for MIN UR problem and it outperforms Sadegh's algorithm in sense of the resulted minimum inconsistency number, even though the test problems are linear.

Surface pigments,algal biomass profiles,and potential production of the euphotic layer:Relationships reinvestigated in view of remote-sensing applications

Maps of surface chlorophyllous pigment (Chl a + Pheo a) are currently produced from ocean color sensors. Transforming such maps into maps of primary production can be reliably done only by using light-production models in conjuction with additional information about the column-integrated pigment content and its vertical distribution. As a preliminary effort in this direction. $\ticksim 4,000$ vertical profiles pigment (Chl a + Pheo a) determined only in oceanic Case 1 waters have been statistically analyzed. They were scaled according to dimensionless depths (actual depth divided by the depth of the euphotic layer, $Z_e$) and expressed as dimensionless concentrations (actual concentration divided by the mean concentration within the euphotic layer). The depth $Z_e$ generally unknown, was computed with a previously develop bio-optical model. Highly sifnificant relationships were found allowing $\langle C \rangle_tot$, the pigment content of the euphotic layer, to be inferred from the surface concentration, $\bar C_pd$, observed within the layer of one penetration depth. According to their $\bar C_pd$ values (ranging from $0.01 to > 10 mg m^-3$), we categorized the profiles into seven trophic situations and computed a mean vertical profile for each. Between a quasi-uniform profile in eutrophic waters and a profile with a strong deep maximum in oligotrophic waters, the shape evolves rather regularly. The wellmixed cold waters, essentially in the Antarctic zone, have been separately examined. On average, their profiles are featureless, without deep maxima, whatever their trophic state. Averaged values their profiles are featureless, without deep maxima, whatever their trophic state. Averaged values their profiles are featureless, without deep maxima, whatever their trophic state. Averaged values of $ρ$, the ratio of Chl a tp (Chl a + Pheo a), have also been obtained for each trophic category. The energy stored by photosynthesizing algae, once normalized with respect to the integrated chlorophyll biomass $\langle C \rangle _tot $ is proportional to the available photosythetic energy at the surface via a parameter $ψ∗$ which is the cross-section for photosynthesis per unit of areal chlorophyll. By tanking advantage of the relative stability of $ψ∗.$ we can compute primary production from ocean color data acquired from space. For such a computation, inputs are the irradiance field at the ocean surface, the "surface" pigment from which $\langle C \rangle _tot$ can be derived, the mean $ρ value pertinent to the trophic situation as depicted by the $\bar C_pd or $\langle C \rangle _tot$ values, and the cross-section $ψ∗$. Instead of a contant $ψ∗.$ value, the mean profiles can be used; they allow the climatological field of the $ψ∗.$ parameter to be adjusted through the parallel use of a spectral light-production model.

黄土高原中部丘陵区生态农业结构模式及阶段目标

分析了黄土丘陵区农业生产现状和存在的主要问题 ,指出广种薄收习惯是导致土地利用不合理 ,植被遭到破坏 ,进而水土流失加剧和生态环境恶化 ,农业生产力降低的根源。该地区生态农业建设的核心是改变广种薄收习惯 ,治理水土流失 ,不断调整优化土地利用和产业结构。依据土地资源状况提出目前阶段 1 2 34的土地利用结构模式。认为在占总土地面积 2 0 %的基本农田和果园 ,只要实行集约化经营就可实现较高的经济效益 ,70 %的土地应为林草地。根据生态农业的基本原则和当前生产水平提出生态农业建设三个阶段的不同指标和适宜治理度 ,当前该地区主导产业的发展应以资源—结构—质量型模式为主

实行三个基本转变促进黄土丘陵区农业和经济持续发展

依据黄土丘陵区几十年治理开发的正反两方面经验 ,认为该地区要真正抓住西部大开发大好机遇 ,迅速改变落后面貌 ,实现农业和经济的快速及可持续发展 ,必须在指导思想和农业生产上实现三个根本转变。即 :变以粮为主的广种薄收为高效的农林果牧综合发展 ;变自给自足的小农经济为以商品生产为主的集约经营 ;变生态经济相悖论为生态经济统一观

黄土旱塬麦田生态系统能流特征及评价

根据长武试区 1 986年～ 1 995年连续 1 0年的统计资料并结合田间试验 ,对黄土旱塬典型农田生态系统——冬小麦农田系统能量的投入产出、流向、流量与转化效率进行了较为系统的研究。结果表明 ,能量平衡中人工辅助能的投入逐渐增加 ,化肥能投入比例逐渐超过有机肥能 ;该区农业已发展到无机—有机复合阶段 ,农业生产中机械化程度有所提高。通过统计分析 ,得出提高无机能的投入比例可提高能量的产投比 ,增加化肥能投入水平则可提高能量的总产出 ,指出应在机械化条件下实行秸秆还田和多途径增加有机肥投入 ,调整能量投入结构 ,提高能量转化效率 ,提高光能利用率