检索结果-南通市图书馆

Enhancing the stability and ecological safety of mass-reared transgenic strains for field release by redundant conditional lethality systems

引用

Insect Science 2016年第2期23卷 225-234页

作者： alfred M. Handler USDA Agricultural Research Service Center for Medical Agricultural and Veterinary Entomology Gainesville FL 32608 USA

The genetic manipulation of agriculturally important insects now.allow. the development of genetic sexing and male sterility systems for more highly efficient biologically-based population control programs, most notably the Sterile Insect Technique （SIT）, for both plant and animal insect pests. Tetracycline-suppressible （Tet-off） conditional lethal systems may function together so that transgenic strains w.ll be viable and fertile on a tetracycline-containing diet, but female-lethal and male sterile in tetracycline-free condi- tions. This w.uld allow.their most efficacious use in a unified system for sterile male-only production for SIT. A critical consideration for the field release of such transgenic insect strains, how.ver, is a determination of the frequency and genetic basis of lethality revertant survival. This w.ll provide know.edge essential to evaluating the genetic stability of the lethality system, its environmental safety, and provide the basis for modifications ensur- ing optimal efficacy. For Tet-off lethal survival determinations, development of large-scale screening protocols should also allow.the testing of these modifications, and test the ability of other conditional lethal systems to fully suppress propagation of rare Tet-off survivors. If a dominant temperature sensitive （DTS） pupal lethality system proves efficient for sec- ondary lethality in Drosophila, it may provide the safeguard needed to support the release of sexing/sterility strains, and potentially, the release of unisex lethality strains as a form of genetic male sterility. Should the DTS Prosβ21 mutation prove effective for redundant lethality, its high level of structural and functional conservation should allow.host-specific cognates to be created for a w.de range of insect species.

关键词： conditional lethality ecological safety redundant lethality Sterile InsectTechnique transgenic insects

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The effect of Common Cuckoo parasitism on the annual productivity of a host population

引用

Avian Research 2024年第2期15卷 287-291页

作者： alfred Trnka Department of Biology University of TrnavaPriemyselna 491843TrnavaSlovakia

Avian interspecific brood parasitism is an excellent system for studying coevolutionary processes in nature because brood parasites directly affect host reproductive *** research on avian brood parasitism has,therefore,focused primarily on specific host anti-parasite behaviours and parasite ***,the population-level consequences of brood parasitism for host species are poorly *** study investigated the effect of Common Cuckoo(Cuculus canorus)parasitism on the productivity of a local population of the Great Reed w.rbler(Acrocephalus arundinaceus)host in south-w.stern Slovakia.A total of 495 females nesting at the studied site successfully fledged 1321 of their ow. young and 63 young of the Common Cuckoo over the course of 15 years(2008-2022),and the annual rate of successful parasitism ranged from 18% to 44% over this *** predicted,higher rates of successful cuckoo parasitism significantly reduced the annual productivity of the local Great Reed w.rbler population,and its contribution to decreased host reproductive success w.s at about the same rate as overall nest failure caused by predation and other environmental *** a heavily parasitized population w.s probably maintained by immigrants from other populations and density-dependent selection,w.ich is also consistent w.th source-sink ***,further long-term studies monitoring parasitized populations are required to confirm these findings.

关键词： Acrocephalus arundinaceus Cuculus canorus Great Reed w.rbler Population grow.h Reproductive success

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

"Molecular Markers and Chemotherapy for Low.Grade Gliomas"

"Molecular Markers and Chemotherapy for Low-Grade Gliomas"

引用

中国抗癌协会神经肿瘤专业委员会第八届学术会议

作者： w. K. alfred Yung Anderson Cancer Center Houston TX

＜正＞The w.O classification has been the main system for pathologic diagnosis and classification of malignant gliomas. It is based primarily on morphologic features such as cellularity, nuclear polymorphism, neovascu...

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

Three- and Four-Dimensional Generalized Pythagorean Numbers

引用

Advances in Pure Mathematics 2024年第1期14卷 1-15页

作者： alfred w.nsche Institute of Physics Humboldt University Berlin Germany

The Pythagorean triples (a, b | c) of planar geometry w.ich satisfy the equation a2+b2=c2 w.th integers (a, b, c) are generalized to 3D-Pythagorean quadruples (a, b, c | d) of spatial geometry w.ich satisfy the equation a2+b2+c2=d2 w.th integers (a, b, c, d). Rules for a parametrization of the numbers (a, b, c, d) are derived and a list of all possible nonequivalent cases w.thout common divisors up to d2 is established. The 3D-Pythagorean quadruples are then generalized to 4D-Pythagorean quintuples (a, b, c, d | e) w.ich satisfy the equation a2+b2+c2+d2=e2 and a parametrization is derived. Relations to the 4-square identity are discussed w.ich leads also to the N-dimensional case. The initial 3D- and 4D-Pythagorean numbers are explicitly calculated up to d2, respectively, e2.

关键词： Number Theory Pythagorean Triples Tesseract 4-Square Identity Diophantine Equation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Optic Axes and Elliptic Cone Equation in Coordinate-Invariant Treatment

引用

Journal of Modern Physics 2022年第6期13卷 1001-1043页

作者： alfred w.nsche Institut für Physik Humboldt-Universit&auml t Newtonstr Berlin Germany

w. derive for crystal optics in coordinate-invariant w.y the cone approximation of refraction vectors in the neighborhood of optic axes and determine its invariants and eigenvectors. It proved to describe an elliptic cone. The second invariant of the operator of the w.ve equation w.th respect to similarity transformations determines the special cases of degeneration including the optic axes w.ere the polarization of the w.ves due to self-intersection of the dispersion surface is not uniquely determined. This second invariant is included in all investigations and it is taken into account in the illustrations. It is biquadratic in the refraction vectors and the corresponding forth-order surface in three-dimensional space splits in tw. separate shells and a non-rational product decomposition describing this is found. w. give also a more general classification of all possible solutions of an equation w.th an arbitrary three-dimensional operator.

关键词： Permittivity Tensor Principal Permittivities Three-Dimensional Operator of w.ve Equation Operator Invariants Refraction Vector Ray Vector Cone Ap-proximation in Neighborhood of Optic Axis Conical Refraction

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Mathematical Aspects of SU (2) and SO(3,R) Derived from Tw.-Mode Realization in Coordinate-Invariant Form

引用

Journal of Modern Physics 2023年第3期14卷 361-413页

作者： alfred w.nsche Institut für Physik Humboldt-Universit&#228t Newtonstr. 15 Berlin Germany

Some mathematical aspects of the Lie groups SU (2) and in realization by tw. pairs of boson annihilation and creation operators and in the parametrization by the vector parameter instead of the Euler angles and the vector parameter c of Fyodorov are developed. The one-dimensional root scheme of SU (2) is embedded in tw.-dimensional root schemes of some higher Lie groups, in particular, in inhomogeneous Lie groups and is represented in text and figures. The tw.-dimensional fundamental representation of SU (2) is calculated and from it the composition law.for the product of tw. transformations and the most important decompositions of general transformations in special ones are derived. Then the transition from representation of SU (2) to of is made w.ere in addition to the parametrization by vector the convenient parametrization by vector c is considered and the connections are established. The measures for invariant integration are derived for and for SU (2) . The relations betw.en 3D-rotations of a unit sphere to fractional linear transformations of a plane by stereographic projection are discussed. All derivations and representations are tried to make in coordinate-invariant w.y.

关键词： Boson Operators Lie Algebra Root Diagram Invariant Integration Hamilton-Cayley Identity Cayley-Gibbs-Fyodorov Parametrization Composition Law Quaternion Stereographic Projection Fractional Linear Transformation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Approach to a Proof of the Riemann Hypothesis by the Second Mean-Value Theorem of Calculus

引用

Advances in Pure Mathematics 2016年第13期6卷 972-1021页

作者： alfred w.nsche Humboldt-Universitü t Berlin Institut für Physik Nichtklassische Strahlung (MPG) Berlin Germany

By the second mean-value theorem of calculus (Gauss-Bonnet theorem) w. prove that the class of functionsw.th an integral representation of the form w.th a real-valued function w.ich is non-increasing and decreases in infinity more rapidly than any exponential functions , possesses zeros only on the imaginary axis. The Riemann zeta function as it is know. can be related to an entire functionw.th the same non-trivial zeros as . Then after a trivial argument displacement w. relate it to a function w.th a representation of the form w.ere is rapidly decreasing in infinity and satisfies all requirements necessary for the given proof of the position of its zeros on the imaginary axis z=iy by the second mean-value theorem. Besides this theorem w. apply the Cauchy-Riemann differential equation in an integrated operator form derived in the Appendix B. All this means that w. prove a theorem for zeros of on the imaginary axis z=iy for a w.ole class of function w.ich includes in this w.y the proof of the Riemann hypothesis. This w.ole class includes, in particular, also the modified Bessel functions for w.ich it is know. that their zeros lie on the imaginary axis and w.ich affirms our conclusions that w. intend to publish at another place. In the same w.y a class of almost-periodic functions to piece-w.se constant non-increasing functions belong also to this case. At the end w. give shortly an equivalent w.y of a more formal description of the obtained results using the Mellin transform of functions w.th its variable substituted by an operator.

关键词： Riemann Hypothesis Riemann Zeta Function Xi Function Gauss-Bonnet Theorem Mellin Transformation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Tw. Concepts in Optics of Anisotropic Dispersive Media and Polariton Case in Coordinate-Invariant w.y

引用

Journal of Modern Physics 2022年第4期13卷 574-619页

作者： alfred w.nsche Institut für Physik Humboldt-Universit&auml t Berlin Germany

Tw. concepts of phenomenological optics of homogeneous, anisotropic and dispersive media are compared, the younger and more general concept of media w.th spatial dispersion and the older concept of (bi)-anisotropic media w.th material tensors for electric and magnetic induction w.ich only depend on the frequency. The general algebraic form of the polarization vectors for the electric field and their one-dimensional projection operators is discussed w.thout the degenerate cases of optic axis for w.ich they become tw.-dimensional projection operators. Group velocity and diffraction coefficients in an approximate equation for the slow.y varying amplitudes of beam solutions are calculated. As special case a polariton permittivity for isotropic media w.th frequency dispersion but w.thout losses is discussed for the usual passive case and for the active case (occupation inversion of tw. energy levels that goes in direction of laser theory) and the group velocity is calculated. For this active case, regions of frequency and w.ve vector w.th group velocities greater than that of light in vacuum w.re found. This is not fully understood and due to large diffraction is likely only to realize in guided resonator form. The notion of “negative refraction” is shortly discussed but w. did not find agreement w.th its assessment in the original paper.

关键词： Spatial and Frequency Dispersion Bi-Anisotropic Media Uniaxial Media Passive and Active Media Negative Refraction Operator Invariants Complementary Operator Group Velocity

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

美国全球权力的兴衰

引用

2019年

作者： (美)阿尔弗雷德·w.麦考伊(alfred w. McCoy)

来源：南通市图书馆图书评论

学校读者我要写书评

暂无评论

Boundary Conditions for Sturm-Liouville Equation w.th Transition Regions and Barriers or w.lls

引用

Advances in Pure Mathematics 2021年第4期11卷 254-295页

作者： alfred w.nsche Institut für Physik Humboldt-Universit&#228 t Nonclassical Radiation Berlin Germany

By means of expansions of rapidly in infinity decreasing functions in delta functions and their derivatives, w. derive generalized boundary conditions of the Sturm-Liouville equation for transitions and barriers or w.lls betw.en tw. asymptotic potentials for w.ich the solutions are supposed as know.. w. call such expansions “moment series” because the coefficients are determined by moments of the function. An infinite system of boundary conditions is obtained and it is show. how.by truncation it can be reduced to approximations of a different order (explicitly made up to third order). Reflection and refraction problems are considered w.th such approximations and also discrete bound states possible in nonsymmetric and symmetric potential w.lls are dealt w.th. This is applicable for large w.velengths compared w.th characteristic lengths of potential changes. In Appendices w. represent the corresponding foundations of Generalized functions and apply them to barriers and w.lls and to transition functions. The Sturm-Liouville equation is not only interesting because some important second-order differential equations can be reduced to it but also because it is easier to demonstrates some details of the derivations for this one-dimensional equation than for the full three-dimensional vectorial equations of electrodynamics of media. The article continues a paper that w.s made long ago.

关键词： Schrödinger Equation Drude Approximation Transition Layer Potential Barrier Potential w.ll Reflection Refraction Moment Series Generalized Functions Delta Function and Its Derivatives Discrete or Bound Eigenstates

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：