具有可变时滞的高阶非自治中立型差分方程的振动性

研究具有可变时滞的高阶非自治中立型差分方程△~m(X_n-cx_(n-k)) h(n,x_(n-l_n))=0 (n=0,1,2,...)的振动性．利用Banach空间的压缩映象原理,得到了这类差分方程振动的必要条件．利用偏序集中的Knaster不动点定理,得到了这类方程振动的充分必要条件．同时得到了这类差分方程存在最终正解的准则．     

带有分段常数变量的单种群模型的全局稳定性和振动性（英文）

研究了带有分段常数变量的单种群连续模型的全局稳定性和振动性.通过计算将连续模型转化为对应的差分模型,首先研究发现当模型的参数和初值条件满足一定条件时,差分方程的任一正解是单调有界的,且正平衡态是全局渐近稳定的.其次以参数β_1作为分类标准,在两种情况下研究得到当参数r属于某一区间时,差分方程的解是振动的.最后数值模拟验证了理论分析的正确性.     

具有连续变量的多时滞二阶非线性中立型差分方程的振动性

用分析的方法研究了一类具有连续变量的多时滞二阶非线性中立型差分方程解的振动性,给出了该类方程解振动和差分算子振动的几个充分条件.     

一阶泛函差分方程解振动的充分和必要条件

得到具有多个时滞的差分方程：An l-An m^∑i=1piAn-ki=0解振动的充分和必要条件,这里pi全是正数,ki是正整数,i=1,2,3,…,m,(或pi是负数,ki是负整数)。     

一类神经传播方程的特征差分方法与分析

首先对给定的方程进行恒等变换,再把MMOCAA差分方法与UNO插值相结合,提出了方程的MMOCAA-UNO差分方法,避免了基于k次Lagrange插值的MMOCAA差分方法在方程的解的陡峭前沿附近产生振荡．通过引入插值算子等方法给出了格式的误差估计．数值实验说明理论分析的正确性和格式的有效性．     

时滞Logistic型差分方程的振动及稳定性

本文获得了如下Xn 1=xnexp(a bxn-k^p-cxn-1^q）时滞Logistic型差分方程所有正解关于其平衡点振动的充要条件，同时还获得了一个正平衡点渐近稳定的充分条件，其中A∈（0，∞），B∈（-∞，O]，C∈（0，∞），K,l∈N。     

一类高阶非线性中立型时滞差分方程正解的存在性定理

研究了一类高阶非线性中立型时滞差分方程正解的存在性,给出了该类方程存在有界最终正解的一个充要条件。     

含阻尼项二阶泛函差分方程的振动性质

从解的渐近状态入手,应用分类讨论方法和Raccati技巧,讨论了一类广泛的二阶泛函差分方程解的振动性与非振动性,建立了四个新的振动性定理,推广并改进了已有文献中的相关结果.     

一阶线性差分微分方程振动的充要条件及应用

本文的目的是建立一阶线性差分微分方程 (dx)/(dt)=-sum from i=1 to n p_i(t)x(t-i_x(t)) (1)的所有解关于θ振动的等价条件,然后把所得结果应用于生物自身调节反馈滞后型方程(dN(t))/(dt)=rN(t)[1-(N(t-i))/p] (2)的更一般形式     

含非线性扩散项的脉冲双曲型方程的振动性分析

研究一类含非线性扩散项和脉冲效应的双曲型方程的振动性,利用脉冲微分不等式技巧,建立了该类方程在Dirichlet边值条件下所有解振动的充分条件.结论充分表明振动是由脉冲效应引起的.     

四川西部川赤芍野生居群的表型多样性分析

为揭示四川西部川赤芍〔Paeonia anomala subsp.veitchii(Lynch)D.Y.Hong et K.Y.Pan〕表型性状的变异规律,对川赤芍6个野生居群的株高、茎基粗、叶片和花部性状等15个表型性状进行了比较;并在此基础上,对各表型性状进行了方差分析、变异系数(CV)分析、离散系数(R′)分析、Shannon-Weaver遗传多样性指数(H′)分析、主成分分析和聚类分析.结果表明:川赤芍15个表型性状在居群间均存在极显著差异;除顶小叶长宽比外,其他14个表型性状在居群内均存在极显著或显著差异.15个表型性状在居群内的F值均明显小于居群间.15个表型性状中,每枝着花量的CV平均值最大(33.68%),花瓣数的CV平均值最小(11.26%);6个居群中,阿坝州小金县两河乡(P1)和阿坝州小金县四姑娘山镇(P2)居群的CV平均值较大,阿坝州金川县万林乡(P4)和阿坝州马尔康县卓克基乡(P5)居群的CV平均值居中,阿坝州汶川县卧龙自然保护区(P3)和甘孜州炉霍县充古乡(P6)居群的CV平均值最小.15个表型性状中,株高的R′平均值最大(64.48%),萼片数和苞片数的R′平均值均最小(37.50%);6个居群中,P2居群的R′平均值最大(56.66%),P3居群的R′平均值最小(43.65%).川赤芍6个居群15个表型性状的CV值和R′值的平均值分别为18.70%和49.80%.川赤芍15个表型性状和6个居群的H′平均值均较高,分别为1.6475和1.4510.主成分分析结果显示:叶片形态和花部特征是川赤芍表型变异的主要因子.聚类分析结果显示:在欧氏距离7.12处,川赤芍6个居群被分成2支,其中,P6居群单独聚为一支,其他5个居群聚为另一支,表明生境相似的居群更早地聚在一起.研究结果显示:四川西部川赤芍表型性状在居群间变异丰富,这与其叶片形态、花部特征及生境关系密切.     

Division of Regulatory Systems of Cells of the Institute of Biochemistry of the Ukrainian National Academy of Sciences (L'viv). History, achievements and perspectives

A short review presented deals with the history of biochemistry development in the western regions of Ukraine. Two principal biochemical schools were founded here by J. Parnas (1884-1949) and S. Gzhytskiy (1900-1976). While most of the students and collaborators of Prof. J. Parnas left for Poland and other western states, those ones of Prof. S. Gzhytskiy stayed in Lviv and other scientific centers of Ukraine. In 1979 Prof. S. Kusen (one of Gzhytskiy's former students and collaborators) and Prof. G. Shavlovsky headed two scientific departments founded in Lviv at O. V. Palladin Institute of Biochemistry. This event could be considered as the beginning of modern biochemistry development in the western regions of Ukraine. Since 1992 in Lviv there exists the Division of Regulatory Cell Systems of O. V. Palladin Institute of Biochemistry of the National Academy of Sciences of Ukraine headed since 1995 by Prof. R. Stoika. Four Departments work in the structure of this Division: 1) the Department of Biochemistry of Cell Differentiation headed in 1979-1997 by S. Kusen and since 1997 by L. Drobot; 2) the Department of Regulation of Cell Proliferation created in 1993 and headed by R. Stoika; 3) the Department of Biochemical Genetics created in 1988 and headed by A. Sibirny; 4) the Department of Regulation of Synthesis of Low Molecular Compounds headed in 1979-1996 by G. Shavlovsky and since 1996 by D. Fedorovych. Division of Regulatory Cell Systems is presently the leading scientific center in Ukraine in the study of the biochemical mechanisms of proliferation, differentiation and apoptosis of normal and tumour cells and in the development of effective biotechnological processes for obtaining the biologically active substances using yeast. Numerous publications of its collaborators in the high impact factor scientific magazines as well as the realisation of the international grants confirm this statement. Taking into account the high level of scientific research and availability of highly skilled scientists at the Division in 1999 the Presidium of the National Academy of Sciences of Ukraine took a resolution to transform the Division into the Institute of Cell Biology of the National Academy of Sciences of Ukraine, which was founded in 2000 on the basis of the Division.     

Measurement of size distributions of bacterial cells

Harvey, R. J. (University of California, Davis), and Allen G. Marr. Measurement of size distributions of bacterial cells. J. Bacteriol. 92:805-811. 1966.-Apparatus for the automatic determination of the volume distribution of particles by measurement of the amplitude of pulses generated in a Coulter transducer is described. Distributions of volume estimated by direct measurement of pulse amplitude are distorted by coincidence. Differentiation and integration of the pulses followed by automatic pulse-height analysis permit precise measurement of volume of latex spheres and of bacteria over a range of at least 0.25 to 20 mu(3). The apparatus is also capable of accurate determination of particle concentration over a wide range. Other advantages are the speed of both measurement and data processing.     

T.l.c. enantiomeric separation of amino acids

Resolution of enantiomers is very important particularly in the fields of asymmetric synthesis, mechanistic studies, geochronology, studies of structure-function relationship of proteins, pharmacology, and medicine. Various chromatographic methods have replaced the classical fractional crystallization, seeding and enzymatic procedures. Of these, t.l.c. provides a direct, simple, and inexpensive method for resolution of enantiomers of amino acids and their derivatives. Ligand exchange, ion exchange, and molecular inclusion complexation have been the basis of t.l.c. resolution of enantiomers of amino acids and their derivatives. The innovation of new plate types, and methods of development and detection have renewed interest in the direct resolution of enantiomers of amino acids, their derivatives and a variety of other compounds by t.l.c. The present report provides an overview of some of the more recent approaches to the direct t.l.c. resolution of amino acids and their derivatives together with special advantages and scope of t.l.c.     

Experimentelle Untersuchungen zum Freisetzungsmechanismus von Neurohormonen nach elektrischer Reizung der Corpora cardiaca von Periplaneta americana in vitro

Releasing of neurohormones by in vitro stimulation of the corpora cardiaca of Periplaneta americana by means of suction electrodes and by simultaneous application of sympathicomimetics and -lytics as well as parasympathicomimetics and -lytics was investigated. The release of neurohormone D by stimulation of N.c.c. I in the presence of atropine in bath-fluid is inhibited. Contrary to this, the presence of eserine stimulates release. Application of reserpine, as well as of the sympathicolytics tolazolin, retinin, and guanethidin, does not influence release of this hormone in connexion with the stimulation of N.c.c. I. These results indicate that the release of neurohormone D by stimulation of N.c.c. I is regulated by cholinergic components. On the other hand, release of the hyperlgykaemic factor by electrical stimulation of N.c.c. II is controlled by adrenergic components. This conclusion results from the increase of the release rate caused by reserpine. Sympathicolytics decreased the release rate. Atropine and eserine do not influence hormone release in connexion with the stimulation of N.c.c. II.     

新疆南北疆灌木植物组成及区系比较

在文献和标本查阅以及野外调查的基础上,比较了北疆和南疆灌木植物的种类、组成及分布区类型的差异,并分析了北疆和南疆灌木植物的相似性。结果表明:新疆共分布有野生灌木植物39科127属462种,其中北疆分布有37科104属350种,南疆分布有28科63属160种。北疆和南疆灌木植物中含2~10种的科最多,分别占北疆和南疆灌木植物总科数的59.5%和60.7%,共有的优势科为菊科(Compositae)、豆科(Leguminosae)和藜科(Chenopodiaceae);在属级水平上均以含1种的属和含2~10种的属占优势。北疆和南疆灌木植物科的分布区类型均以世界广布型和北温带分布型为主,其中,在北疆灌木植物中这2个分布型科的数量分别占总科数的43.2%和32.4%、在南疆灌木植物中分别占总科数的50.0%和28.6%。北疆和南疆灌木植物属的分布区类型均以地中海区、西亚至中亚分布型和北温带分布型为主,其中,在北疆灌木植物中这2个分布型属的数量分别占总属数的26.9%和22.1%、在南疆灌木植物中则分别占总属数的31.7%和27.0%。北疆和南疆灌木植物中分别包含特有种15和8种,此外还包含一些珍稀濒危种类及古老的孑遗种。北疆与南疆灌木植物区系在科、属、种水平上的相似性系数分别为86.1%、69.4%和40.8%,表明在科、属水平上2个区域的灌木植物区系有较为密切的关系。研究结果显示:北疆和南疆灌木植物在种类组成、分布区类型和特有种数量等方面有一定差异,但均具有明显的温带性质,并形成了一系列适应于当地生态环境的生存策略。     

碱蒿营养器官的扫描电镜观察研究

用扫描电子显微镜对碱蒿（Artemisia anethifolia）营养器官的解剖学特征进行了观察与研究。结果表明：碱蒿属于典型的泌盐盐生植物。叶肉质化,表皮上气孔为无规则型气孔,密集下陷,有较多的盐囊泡和分杈腺毛分布,表皮细胞外壁加厚,外壁的外层角质化,为等面叶,栅栏组织细胞排列疏松,叶中央为发达的储水组织,木质部有多束维管束;茎表皮上有少许气孔,并分布有腺毛和众多盐囊泡,表皮细胞外壁加厚形成角质层,皮层宽度较小,皮层薄壁组织细胞内可见淀粉粒,中柱后生木质部为口径大的导管,原生木质部为口径小的导管,管内充满盐晶体,中间有发达的贮水薄壁细胞;根的表皮细胞排列疏松,外皮层细胞排列紧密而整齐,中部皮层薄壁细胞层数较多,细胞中贮藏有许多淀粉粒,内皮层细胞排列紧密,初生木质部导管发达,内部周围存在大量盐晶体,根的次生木质部有通气组织。这些解剖结构均表现出碱蒿具有适应盐碱、干旱生境的结构特征。     

Toxigenic Aspergilli and Penicillia Isolated from Aged, Cured Meats

Eighty-nine cultures of Aspergillus and 54 cultures of Penicillium isolated from aged, cured meats were tested for toxicity to chicken embryos. Two of 22 isolates of A. ruber, 5 of 28 A. repens, 2 of 12 A. sydowi, 1 of 12 A. restrictus, 2 of 7 A. amstelodami, 1 of 2 A. chevalieri, and an A. fumigatus isolate exhibited toxicity. Similarly, 2 of 15 isolates of P. expansum, 1 of 3 P. notatum, 1 of 2 P. brevi-compactum, and 1 of 8 Penicillium spp. were found to be the most toxic. Among these fungi, the chloroform extract from the growth of an A. sydowi isolate showed the greatest toxicity. There was no direct or indirect evidence that aged, cured meats contain toxic metabolites.     

Report on the Na+/H+ Exchanger Satellite Meeting at the 53rd Annual Meeting of the Canadian Society of Biochemistry, Molecular and Cellular Biology

The Satellite Meeting on Na+/H+ Exchangers, held on 17 April 2010, covered a range of new developments in this field. The symposium was chaired by Dr. Larry Fliegel, University of Alberta, and the speakers were Dr. John Orlowski of McGill University, Dr. Jan Rainey of Dalhousie University, Dr. Etana Padan of The Hebrew University of Jerusalem, Dr. Masa Numata of The University of British Columbia, Dr. Pavel Dibrov from the University of Manitoba, Dr. Todd Alexander of the University of Alberta, and Grant Kemp of the University of Alberta. Talks ranged from organellar pH homeostasis to structure and function of Na+/H+ exchanger proteins. Highlights of the symposium included elucidation of the structure of transmembrane regions of the NHE1 isoform and development of a new model of the NHE1 protein based on the E. coli Na+/H+ exchanger. The symposium brought together scientists from different corners of the world. The discussions that followed were lively and many scientists received constructive comments from their peers.     

X-ray survey results and costs--A health officer's viewpoint. A preliminary report

The obvious results of a mass chest x-ray survey from a health officer's viewpoint are:1. The early discovery of unknown cases of pathologic conditions of the chest-tuberculosis, neoplasms, heart abnormalities.2. Increase in the community's awareness of its tuberculosis problem.3. Opportunity to work closely with the medical society and the individual private physicians.4. Stimulation of all agencies in a community, health and non-health, to work together on a health project for the good of all of the people.5. Increased cooperation between the local department of public health and other health agencies in a community.6. Opportunity to underline to a staff of a local department of public health the importance of thinking in terms of the department as a whole, rather than in terms of respective divisions or bureaus.7. Opportunity to focus the awareness of the community on its public health services. In relation to costs, there are three aspects from a health officer's viewpoint:1. The planning, together with other agencies, of an adequate budget with full recognition of community resources.2. The planning for estimated expansion of tuberculosis control services both in terms of increased expense for maintenance and operation, and of assignment of personnel to survey staff with resulting curtailment or postponement of other programs.3. The planning for completion of the follow-up program of the x-ray survey and of future continued extension of the total tuberculosis control program as the result of increased community awareness of the tuberculosis problem.