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  • Articles  (5,052)
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  • 2010-2014
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  • 1985-1989  (2,953)
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  • 1
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    Circuits, systems and signal processing 8 (1989), S. 17-23 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The performance of a symmetric nonrecursive filter can be improved by multiple use of the same filter. The method is based on an Amplitude Change Function (ACF). An approach to the design of nonrecursive filters using an ACF is discussed in this paper. The prototype filter chosen is a Recursive Running Sum (RRS) filter which does not require any multipliers for its implementation. The required filter specifications are met by multiple use of the RRS filters. The overall filter requires a much smaller number of multiplications and adders than the one designed using the conventional method. It is shown that this method provides reduced noise due to coefficient quantization and product quantization compared with the conventional design technique.
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  • 2
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    Circuits, systems and signal processing 8 (1989), S. 3-15 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract This paper establishes the large-sample accuracy properties of two nonlinear least-squares estimators (NLSE) of sine-wave parameters: the basic NLSE, which ignores the possible correlation of the noise, and the optimal NLSE, which, besides the sine-wave parameters, also estimates the noise correlation (appropriately parametrized). It is shown that these two NLS estimators have thesame accuracy in large samples. This result provides complete justification for preferring the computationally less expensive basic NLSE over the “optimal” NLSE. Both estimators are shown to achieve the Cramér-Rao Bound (CRB) as the sample size increases. A simple explicit expression for the CRB matrix is provided, which should be useful in studying the performance of sine-wave parameter estimators designed to work in the colored-noise case.
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  • 3
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    Circuits, systems and signal processing 8 (1989), S. 97-119 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract Multidimensional lossless networks are of special interest for use as reference structures for multidimensional wave digital filters [l]–[3]. The starting point of the presented synthesis procedure for two-dimensional representatives of the networks mentioned is a scattering matrix description of the desired multiport. This given matrix is assumed to have those properties which have turned out to be necessary [9], [10] for any scattering matrix of a multidimensional lossless network. The method presented for the synthesis of 2-D reactancem-ports is based mainly on known properties of block-companion matrices and the factorization of a univariable rational matrix which is discrete para-Hermitian and nonnegative definite on the unit circle. The resulting network always contains only a minimal number of frequency-dependent building elements. No restrictions are made concerning the coefficients of the rational entries of the scattering matrix; they may be either real or complex, so as to include even complex networks which are of special interest for multi-dimensional wave digital filters [3].
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  • 4
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    Circuits, systems and signal processing 8 (1989), S. 145-162 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract Examples are given concerning the range of applicability of recent representation results that provide a means of studying the input-output properties of nonlinear systems in terms of the familiar impulse-response concept, and which extend the concept of integral transformation to nonlinear maps. We show that such representations, which we call “g-” and “h-representations,” exist for important classes of systems governed by nonlinear integral equations. In particular, it is proved that a large class of maps that have Volterra series representations also have these representations.
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  • 5
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    Circuits, systems and signal processing 8 (1989), S. 133-144 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract Pseudorandom (or maximal length) sequences and arrays have been known for a long time, and have been reported by several authors. Pseudorandom volumes have also been mentioned. This paper presents a different type of sequence of arrays in which the arrays share many properties with the pseudorandom arrays of the literature, and the sequence (or group) of arrays has many properties in common with the pseudorandom sequences. It is proposed that this set of arrays be called a “pseudorandom sequence of arrays,” or PRSAs. Some interesting properties of the PRSA as well as its practical (hardware) implementation have been mentioned. It has also been shown that our result is a special case of the generalN(3)/D(3) case.
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  • 6
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    Circuits, systems and signal processing 8 (1989), S. 207-228 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract For linear time-invariant discrete-time systems, an exponentially convergent recursive parameter identification scheme is derived requiring only that the regression vector be sufficiently exciting, that is the sum of the outer products of the regression vector is eventually positive definite. The algorithm produces a parameter estimate that converges to the batch-form (nonrecursive) least-squares estimate without requiring a persistent excitation. The rate of convergence can be selected as a design parameter. If the regression vector is persistently exciting, it is shown that a forgetting factor can be added to the formulation in such a way that the magnitude of the forgetting factor and the rate of exponential convergence can be set separately.
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  • 7
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    Circuits, systems and signal processing 8 (1989), S. 229-229 
    ISSN: 1531-5878
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    Topics: Electrical Engineering, Measurement and Control Technology
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  • 8
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    Circuits, systems and signal processing 8 (1989), S. 235-260 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The semistate theory of circuits and systems is reviewed with regard to its applications. Among these latter discussed are electronic circuit design and analysis, hysteresis, knot generation, neural networks, and constrained robot characterizations.
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  • 9
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    Circuits, systems and signal processing 8 (1989), S. 289-298 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract Four notions of controllability for general (i.e., possibly nonregular) implicit linear discrete-time systems are considered. Relationships between them are studied. A Hautus-type characterization of all of these notions is also given.
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  • 10
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    Circuits, systems and signal processing 8 (1989), S. 299-312 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract A new concept of system equivalence which allows the establishment of a formal relation between singular and regular systems has been introduced. By applying this concept, an open-loop strategy for finite-time control of a given solvable singular system, which is simple for both computation and implementation, is developed. A strategy for finite-time output feedback control is considered for a continuous singular system. It is shown that provided the system is observable, a desired polynomial command for finite-time control can be determined from a finite sequence of output measurements sampled at discrete instants of time.
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  • 11
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    Circuits, systems and signal processing 8 (1989), S. 313-340 
    ISSN: 1531-5878
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    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract In this paper we study the system-theoretic properties of two related classes of shift-invariant two-point boundary-value descriptor systems (TPBVDSs), namelydisplacement systems for which Green's function is shift-invariant, andstationary systems for which the input-output map is stationary. For such systems it is possible to obtain detailed characterizations of the properties of weak reachability and observability introduced in [16] and of minimality as well. An important difference, that has also been noted before in a different context [9], is that there is a certain level of nonuniqueness in minimal realizations. Another property that is studied in this paper is that of extendibility, i.e., the concept of considering a TPBVDS as being defined on a sequence of intervals of increasing length. Necessary and sufficient conditions for extendibility are given.
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  • 12
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    Circuits, systems and signal processing 8 (1989), S. I 
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  • 13
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    Circuits, systems and signal processing 8 (1989), S. 421-426 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract Scaling of filter variables is central to fixed-point implementation of digital filters. A simple method of scaling based on scaling constants of individual sections of a cascade digital filter is presented. The proposed method saves much computational labor in the implementation of higher-order digital filters. Maximal amplitude expressions of second-order filter transfer functions are also presented.
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  • 14
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    Circuits, systems and signal processing 8 (1989), S. 427-433 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract This paper is concerned with the stability analysis of second-order direct-form digital filters with two magnitude truncation quantizers. Zero-input stability is proved for the parameter regions where no conclusion can be drawn using the methods previously suggested in the literature. The areas of the parameter plane in which only limit cycles of period 1 or 2 exist, are determined and related to the cycle amplitudes. Finally, a transition graph is suggested to study the convergence patterns of the filter output.
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  • 15
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    Circuits, systems and signal processing 8 (1989), S. 467-486 
    ISSN: 1531-5878
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    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The work of digital PLL is analysed. For this analysis a Markov model is used.
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  • 16
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    Circuits, systems and signal processing 8 (1989), S. 455-466 
    ISSN: 1531-5878
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    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The formulation of one-multiplier lattice structures of the Gray-Markel type forinfinite impulse response filters is reviewed. Several special cases of this formulation — including the well-known Gray-Markel normalized lattice—are presented as scaled polynomial versions of the two-multiplier lattice. A new adaptive algorithm is presented for updating the parameters of one-multiplier lattice structured recursive filters. The LMS-based algorithm requires fewer computations than earlier reported algorithms [1]–[4].
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  • 17
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    Circuits, systems and signal processing 8 (1989), S. 49-70 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract In this paper we consider the problem of obtaining minimal-order representations of generalized state-space systems described by equations of the formE x(t)=A x(t)+B u(t),y(t)=C x(t)+D u(t) withE singular and det(sE−A)≠0. The underlying principle is that of removal of impulsive and exponential uncontrollable and unobservable modes. When this is followed by the removal of the remaining impulsive modes, we get a minimal-order generalized or standard state-space representation. Simple reduction procedures and numerical algorithms based on these principles are developed and illustrated by means of two numerical examples.
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  • 18
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    Circuits, systems and signal processing 8 (1989), S. 25-48 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract In this paper we consider models for noncausal processes consisting of discrete-time descriptor dynamics and boundary conditions on the values of the process at the two ends of the interval on which the process is defined. We discuss the general solution and well-posedness of systems of this type and then apply the method of complementary processes to obtain a specification of the optimal smoother in terms of a boundary-value descriptor Hamiltonian system. We then study the implementation of the optimal smoother. Motivated by the Hamiltonian diagonalization results for nondescriptor systems, we show how the descriptor Hamiltonian dynamics can be transformed to two lower-order systems by the use of transformation matrices involving the solution of two generalized Riccati equations. We present several examples illustrating our results and the nature of the smoothing solution and also present equations for covariance analysis of boundary-value descriptor processes including the smoothing error.
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  • 19
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    Circuits, systems and signal processing 8 (1989), S. I 
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  • 20
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    Circuits, systems and signal processing 8 (1989), S. 71-96 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The structure inherent to the centrosymmetric matrices is exploited to obtain factorization results leading to significant computational savings in many engineering applications. Several interesting properties of the matrices are discussed with a view toward algorithm computational complexity. It is shown that the multiplicative complexity involved in the process of principal component (eigen-value/eigenvector) extraction, and in the evaluation of the determinant and inverse of such matrices, can be reduced by nearly 75% by employing the results presented here. The theory presented hereunifies andgeneralizes previous computationally efficient results onseveral specialized generalized centrosymmetric matrices; for example, the class of symmetric centrosymmetric (or doubly symmetric) matrices is shown to be a special case of the class of centrosymmetric matrices, and since the results obtained here are applicable over the field of complex numbers, the factorization results available for centrosymmetric matrices are readilyextended to the complex field. The centrosymmetric matrices play an important role in a number of areas such as pattern recognition, antenna theory, mechanical and electrical systems, and quantum physics. Specific examples of pattern recognition feature selection, a uniform linear antenna array, vibration in structures, and the quantummechanical oscillator are discussed to demonstrate that the theory developed here has a wide range of applications. In addition, certain specialized cases of the centrosymmetric matrices have, in the past, proved their indisputable usefulness in the areas of communication theory, digital filters, linear systems, linear prediction, and speech analysis.
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  • 21
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    Circuits, systems and signal processing 8 (1989), S. 123-132 
    ISSN: 1531-5878
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    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The well-known Jury and Blanchard's stability test for discrete systems is with an array of (2n−3) rows of elements. Raible simplified Jury and Blanchard's array to (n+1) rows by introducing an additional element at the end of each row. Chen and Chan recently derived a Liapunov function through Schwarz' transform to prove the criterion directly and to produce a very compact form. The purpose of this paper is to explore the various singular cases by using the newly established Chen-Chan criterion. Some existing methods for studying singular cases are re-examined under the light shed by Chen and Chan. A by-product is to define and to determine the relative stability of discrete systems.
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    Circuits, systems and signal processing 8 (1989), S. 187-205 
    ISSN: 1531-5878
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    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract A new negative resistance oscillator model was proposed by Walker and Connelly. We investigate the mathematical properties of the associated nonlinear differential equation for a single-mode LCR network oscillator. In particular, we prove that under suitable conditions, small-amplitude stable limit-cycle oscillations can occur. The method of harmonic balance is used to calculate an analytic approximation to the limit-cycle parameters. Also, the general properties of trajectories in phase-space are presented. These predictions are compared with the results obtained by numerical integration of the differential equation.
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  • 23
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    Circuits, systems and signal processing 8 (1989), S. 163-185 
    ISSN: 1531-5878
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    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract A general structure is presented for the block realization of two-dimensional infinite impulse response digital filters, which is based on the two-dimensional matrix convolution equations and the decomposition of their associated transfer function matrices. The proposed decomposition may be considered as an extension of the scalar decomposition technique, which has already been used for the realization of two-dimensional digital filters associated with two-variable polynomials. The decomposition structure is considered in two different forms, which correspond to the direct forms I and II. It is shown that if a given two-dimensional single-input, single-output filter is realizable, then realizable block decomposition structures may be always selected. The proposed approach is general and applies without any restriction for the block implementation of any two-dimensional filter. The resulting structures are characterized by high inherent parallelism, modularity, regularity, reconfigurability, local interconnections, and very high sampling and throughput rates. Thus they are well suited for VLSI implementation and implementation via multiprocessor systems and array processors, such as systolic and wavefront arrays.
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    Circuits, systems and signal processing 8 (1989), S. I 
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  • 25
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    Circuits, systems and signal processing 8 (1989), S. 231-231 
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  • 26
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    Circuits, systems and signal processing 8 (1989), S. 233-234 
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  • 27
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    Circuits, systems and signal processing 8 (1989), S. 261-265 
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    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract It has been observed that the backward differentiation approximation to the solutions ofEx′+Fx =f can fail to converge even pointwise in an initial boundary layer. This paper shows that the approximations converge in a distributional sense even if the exact solution is also distributional.
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    Circuits, systems and signal processing 8 (1989), S. 267-287 
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    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract This paper deals with a refined qualitative analysis of motions of a broad class of continuous time-varying nonlinear singular differential systems. These systems consist of a finite number of first-order differential equations that cannot be set into the normal form. Some novel qualitative concepts, convenient for the description of solutions of singular systems, are introduced and analyzed. These concepts involve some inherent properties of singular systems. General sufficient conditions for these concepts are derived in terms of the existence of a suitable Lyapunov function. Also, for the subclass of singular systems considered, the construction of a Lyapunov function candidate that can be effectively applied in the analysis is proposed. The results obtained generalize some known results in stability theory.
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    Circuits, systems and signal processing 8 (1989), S. 341-355 
    ISSN: 1531-5878
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    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The objective of this paper is to make clear the fundamental importance of thefundamental matrix ϕ k in the analysis of linear discrete-time singular systems. We relateϕ k to the coefficientsR k of the adjoint matrix (zE-A)−1, find an autoregressive recursion for theϕ k , and give the solution of the singular semistate equation in terms ofϕ k . Also discussed are thesemistatetransition matrix and the singular systemTschirnhausen polynomials. We close by giving a stable numerical technique for the computation of the sequenceϕ k that is based on first taking the pencilzE-A to triangular form.
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    Circuits, systems and signal processing 8 (1989), S. 357-373 
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    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract Impulsive solutions of linear homogeneous matrix differential equations are re-examined in the light of the theory of Jordan chains that correspond to infinite elementary divisors of the associated polynomial matrix. Infinite elementary divisors of general polynomial matrices are defined and their relation to the pole-zero structure of polynomial matrices at infinity is examined. It is shown that impulsive solutions are due to Jordan chains of a “dual” polynomial matrix that correspond to infinite elementary divisors that are associated with the orders of “zeros at infinity” of the original matrix.
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    Circuits, systems and signal processing 8 (1989), S. 375-397 
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    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract Generalized linear systems are classified according to their algebraic structure and their regularizability and normalizability properties under generalized state feedback are investigated. New feedback invariants are introduced in terms of the input-space restriction pencil and the Plücker matrix of the system. It is shown that the classification of subspaces of the state space of generalized linear systems is reduced to an equivalent problem of classifying the subspacesV of the domain of an ordered pair (F, G), F, Gεℝm×n. The set of strict equivalence invariants of the restriction pencil (F, G)/V provides a complete, basis-free algebraic characterization and leads to the definition of notions of geometric invariance. The key geometric notions that emerge are those of (F, G)-, (G, F)-, complete-(F, G)-, partitioned(F, G)-, cyclic-, and semicyclic-invariant subspaces. A complete set of geometric algorithms leading to the computation of the above families is also given. The above families of invariant subspaces are characterized in terms of the invariants of (F, G)/V, and this provides the links with their dynamic characterization. These results provide an “open-loop” or “feedback-free” unifying treatment of spaces of generalized systems, which for the case of proper systems is reduced to the standard geometric theory results.
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    Circuits, systems and signal processing 8 (1989), S. 401-419 
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    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract This paper develops a set of fast prime factor decomposition algorithms (PFDAs) for a family of discrete trigonometric transforms of sizeN, whereN is a product of two relatively prime integers. Relevant equations for the PFDAs are derived. Computational procedures are presented followed by a specific example forN= 12. The input and output index mappings necessary for the algorithm are obtained and the computational complexity is briefly outlined.
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    Circuits, systems and signal processing 8 (1989), S. 435-444 
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    Notes: Abstract In the studies of singular systems regularity is often presumed although it may not be satisfied in some real cases. Therefore, natural questions are: What is the difference between regularity and irregularity? How far can we go from regularity to irregularity in the studies of singular systems? This paper partially answers these questions. The results show that the concepts of reachability, controllability, and observability for regular systems can be easily extended to irregular cases. There is minor difference between regular and irregular singular systems. Thus the assumption of regularity is reasonable.
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    Circuits, systems and signal processing 8 (1989), S. 445-453 
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    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract An optimization method is proposed for the design of high-order all-pass delay equalizers for a prescribed group-delay characteristic by using the cascade form realization of digital filters. Unlike other methods, in the proposed method stability is guaranteed by imposing certain mild constraints on the filter coefficients so that the unconstrained optimization technique of Fletcher and Powell is used. To reduce the function minimization time, design values of the parameters of the delay equalizers, obtained by Bernhardt's simplified method, are used as the initial vector in the optimization technique of the proposed method. It is shown that the proposed method for the design of optimal delay equalizers results in all classes of equalizers with real and complex poles and approximates the prescribed group delay more accurately.
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    Circuits, systems and signal processing 8 (1989), S. I 
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    Circuits, systems and signal processing 8 (1989), S. 487-506 
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    Notes: Abstract Given the Volterra series representation of a single input, single output nonlinear system, we examine conditions on the Volterra kernels that determine if the system is in some sense equivalent to a linear system. The systems considered herein are known as “feedback linearizable” systems. Feedback linearizable systems are usually discussed in terms of their state-space representations. A key result relates the Volterra series description of a feedback linearizable system to its state-space description.
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    European journal of wildlife research 24 (1978), S. 47-50 
    ISSN: 1439-0574
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Description / Table of Contents: Summary Three cases of anomalies of the skull in a 12 month old female roe deer are described and illustrated by two photographs: 1. Retardation of the linear expansion of the ossa nasalia; 2. Hypertrophy of the tubera frontalia; 3. Malformation of the rami mandibularum and their processi coronoidei.
    Abstract: Résumé Trois cas d'irrégularités du crâne chez un Chevreuil femelle d'un an sont décrits et illustrés à l'aide de deux photos. En détail il s'agit d'une 1. retention de la croissance des ossa nasalia; 2. hypertrophie des tubera frontalia; 3. malformation des rami mandibularum et ses processi coronoidei.
    Notes: Zusammenfassung Es wird über Regelwidrigkeiten am Schädel eines 12 Monate alten Rickenkitzes berichtet. Die durch zwei Fotos belegten Anomalien sind folgende: 1. Verkürzung der Nasenbeine; 2. Hypertrophie der Stirnwülste; 3. Deformierung des Unterkieferastes, insbesondere Verbiegung des Muskelfortsatzes.
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    European journal of wildlife research 24 (1978), S. 155-166 
    ISSN: 1439-0574
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Description / Table of Contents: Summary By “single food diet” is meant a mixture which contains all the nutritive substances, minerals and vitamins required for body mainternance and growth, with a balanced proportion of energy units. Especially for the feeding of ruminant cloven-hoofed game animals, such a food has great nutritional and physiological advantages over a conventional concentrate of other foods such as cereals, beet, hay or straw since all the components are taken simultaneously by the game animal. In this way it is possible to avoid an unbalanced food intake which, in the case of ruminants, may easily lead to damage to the rumen flora and may therefore be an important cause of illness. Silages have proved themselves to be particularly good in the feeding of ruminant cloven-hoofed game animals. In what is by now an 8-year study in three forest administrative areas of the north-west Eifel, a single food silage has been introduced and tested. Apple cores, sugar beet leaves, minerals and vitamins form the basic components along with hay or straw. Production is made easier with a power food chopper. A structured feed like this is ideal for ruminants; it is readily eaten by the animals and ad-lib intake meets maintenance needs. Costs are in the region of 90 to 100 DM per 1000 kg. In order to cut the daily production costs, 29 self-feeder troughs have so far been set up successfully; through these a permanent supply of food is available to the animals. These troughs have the advantage that failures in the food supply do not occur.
    Abstract: Résumé Par aliment complet on entend un composé comprenant toutes les matières nutritives, actives et énergétiques nécessaires au maintien et aux performances d'un animal. En ce qui concerne plus particulièrement l'alimentation des Ongulés-gibier, une telle nourriture présente, par rapport aux concentrés usels ou par rapport à d'autres aliments tels que céréales, betteraves, foins ou pailles, de gros avantages sur le plan physiologique, tous les ingrédients prévus étant absorbés simultanément. On évite de la sorte une alimentation trop exclusive qui, chez les ruminants, peut causer des dommages à la flore stomacale et ètre à l'origine de maladies. Pour l'affouragement des Ongulés-gibier ruminants, l'ensilage s'est avéré particulièrement probant. Voici maintenant huit années qu'un aliment complet sous forme d'ensilage est fabriqué et fait l'objet d'essais dans trois régions forestières du Nord-Ouest de l'Eifel. Comme composants de base sont utilisés le marc de pommes, la feuille de betteraves sucrières, des vitamines, des éléments minéraux de même que de la paille ou du foin. Pour la fabrication de l'ensilage on se sert d'une hacheuse soufflante. Un tel aliment structuré est destiné à être aussitôt ruminé, est appété par les animaux et couvre, lorsqu'il est distribué ad libitum, les besoins du métabolisme de maintien. Le prix de revient se situe aux environs de 90 à 100 DM par kg. Afin de réduire les frais d'acheminement quotidien de la nourriture, 29 distributeurs automatiques ont d'ores et déjà été installés avec succès, excluant par la même occasion les déficiences liées à un approvisionnement journalier.
    Notes: Zusammenfassung Unter einem „Alleinfutter” ist eine Futtermischung zu verstehen, in der alle für die Erhaltung und Leistung erforderlichen Nähr-, Mineral- und Wirkstoffe mit einem entsprechenden Energieanteil enthalten sind. Speziell für die Fütterung des wiederkäuenden Schalenwildes bildet eine solche Äsung gegenüber einem üblichen Kraftfutter und sonstigen Futterstoffen, wie z. B. Getreide, Rüben, Heu oder Stroh große ernährungsphysiologische Vorteile, da alle vorgesehenen Inhaltstoffe gleichzeitig vom Wild aufgenommen werden. Auf diese Weise kann eine einseitige Futteraufnahme verhindert werden, die bei Wiederkäuern leicht zu Schädigungen der Pansenflora führt und damit wesentliche Ursache für das Auftreten von Erkrankungen ist. Besonders bewährt haben sich zur Verfütterung an wiederkäuendes Schalenwild Silagen. In nunmehr über 8 Jahre durchgeführten Versuchen in 3 Forstverwaltungen der nordwestlichen Eifel ist eine Alleinfutter-Silage hergestellt und erprobt worden. Als Grundkomponenten dienen Apfeltrester, Zuckerrübenblatt, Mineral- und Wirkstoffe sowie Heu oder Stroh. Die Herstellung erfolgt mit Hilfe eines Gebläsehäckslers. Ein solch strukturiertes Futter ist wiederkäuergercht, wird von den Tieren gerne aufgenommen und deckt bei ad libitum-Aufnahme den Erhaltungsbedarf. Die Kosten betragen etwa 90–100 DM/1000 kg. Um die täglichen Ausbringungskosten zu vermindern, sind bisher 29 Selbstfütterungen mit gutem Erfolg eingesetzt worden, durch die dem Wild ständige Äsung zur Verfügung steht und somit Fütterungsfehler dieser Art entfallen
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    European journal of wildlife research 24 (1978), S. 182-186 
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Description / Table of Contents: Summary The paper presents the findings of a study by the district veterinary office in Kleve, which deals with geese losses on the Lower Rhine in N. Rhine Westphalia in connection with a winter thunderstorm. The report suggests lightning strikes, damage by hail, collision with aircraft (bird strikes), and the effects of pressure differences in nose diving from flying at high altitudes as possible causes of death.
    Abstract: Résumé Les pertes observées dans le Bas-Rhin (Rhénanie-Westphalie) par les services vétérinaires de Kleve en liaison avec une perturbation atmosphérique au cours de l'hiver font l'objet d'une discussion. Dans la présente communication, on fait état des causes possibles suivantes: foudre, grèle, collision avec des avions de même que l'effet de variations de pressions atmosphériques lorsque les oiseaux quittent brusquement les hautes altitudes.
    Notes: Zusammenfassung Zur Diskussion gestellt wird der Untersuchungsbefund aus dem Kreisveterinäramt Kleve, der sich mit Gänseverlusten am Niederrhein in Nordrhein-Westfalen in Zusammenhang mit einem Wintergewitter befaßt. Erörtert werden als mögliche Ursachen in der vorliegenden Mitteilung Blitzschlag, Hagelschlag, Zusammenstoß mit Flugzeugen (Vogelschlag) und die Auswirkung von Druckunterschieden bei sturzflugartigem Verlassen großer Flughöhen.
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    European journal of wildlife research 24 (1978), S. 207-211 
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    European journal of wildlife research 35 (1989), S. 137-137 
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    European journal of wildlife research 35 (1989), S. 151-163 
    ISSN: 1439-0574
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Description / Table of Contents: Summary The present report is part of a larger investigation aimed at differentiation among regional Hungarian red deer populations with the aid of morphological antler characteristics of shot red deer. However, this presentation is based on the use of morphological characteristics of cast off antlers as an extension of the previous work and encompasses a broader spectrum of antler formation. From a total of 418 cast off antlers from 4 different Hungarian red deer reserves, 14 morphological parameters were chosen. In order to characterize the distribution of mass along the antlers, a new parameter, the antler focal point was selected. The relationships among the parameters defining the cast off antlers were uniformly investigated within designated limits using simple correlation and regression calculations as well as with factorial analysis. The differences among the individual populations were investigated using graduated discrimination analysis. In numerous cases close positive correlations were demonstrated between the individual parameters; for example, between the selected parameter pairs — antler mass and antler length (r=0.84–0.92), lower antler circumference and antler mass (r=0.79–0.87), as well as upper antler circumference and antler mass (r=0.86–0.95). A comparison of the populations on the basis of the relationships existing between the parameter pairs showed only minimal differences. The factorial analysis demonstrated that the form variability of the cast off antlers can be characterized by the parameters of the lower and the upper antler masses, as well as by the relationship of the two — the antler focal point. For the investigated range of mass (0.3≤×≤3.0 kg), significant differences were in part determined between the individual populations from the results of the discrimination analysis. These differences, however, were very low. The antler focal point was also represented among the 6 parameters selected to differentiate respectively among the 6 different regions investigated. In 50% of the cases the individual cast off antlers were re-assigned to their correct areas of origin. Characteristic antler types could not be demonstrated. The results of the investigations of the antlers and cast off antlers were described. Other ways to compare red deer populations were discussed, whereby the complex investigations between morphological and biochemical-genetic parameters were emphasized.
    Abstract: Résumé Le présent travail se situe dans le cadre de nos recherches sur les possibilités de différencier les souches régionales du Cerf en Hongrie par l'analyse de caractères morphologiques des bois recueillis sur des cerfs abattus. Ces recherches se poursuivent par l'examen des caractéristiques des mues grâce auxquelles un spectre beaucoup plus étendu du développement des bois peut être pris en considération. Sur un total de 418 mues provenant de quatre territoires hongrois colonisés par le Cerf, 14 paramètres morphologiques ont été relevés. Afin de caractériser la répartition des masses sur les mues, on a fait appel à un nouveau paramètre défini comme «centre de gravité du merrain». Les corrélations existant entre les caractères des mues ont été uniformément analysées, dans des limites définies, au moyen de corrélations simples, de calculs de régression et d'analyses factorielles; les différences entre les populations, quant à elles, ont fait l'objet d'une analyse discriminante par degrés. Dans de nombreux cas, des liens positifs étroits ont pu être constatés entre les différents caractères examinés, par exemple, entre les couples de paramètres suivants: masse des merrains et longueur des merrains (r=0,84–0,92), périmètre inférieur des merrains et longueur des merrains (r=0,79–0,87) de même que périmètre supérieur des merrains et masse des merrains (r=0,86–0,95). Une comparaison des populations sur base des corrélations existant entre des différents couples de paramètres ne révèle que de faibles différences. L'analyse factorielle démontra que la variabilité des conformations des merrains pouvait être définie par les caractéristiques de la masse inférieure et de la masse supérieure de même que par le rapport des ces dernières à savoir le centre de gravité. L'analyse discriminante permit de dégager certaines différences significatives entre les différentes populations dans la fourchette observée au niveau des masses des merrains (0,3〈×〈3,0 kg); ces différences étaient cependant peu marquées. Parmi les six caractères départageant les territoires étudiés figurait également le centre de gravité des merrains. Dans 50% des cas en moyenne, les différentes mues purent être classées selon leur territoire d'origine effectif. Des types caractéristiques de bois ne purent être mis en évidence. Les résultats des recherches effectuées sur les bois et sur les mues font l'objet d'une discussion. D'autres études comparatives sur les populations de cerfs sont suggérées en particulier celles, complexes, relevant de caractères morphologiques ainsi que de caractères biochimiques et génétiques.
    Notes: Zusammenfassung Die vorliegende Arbeit nimmt im Rahmen unserer Untersuchungen zur regionalen Differenzierbarkeit ungarischer Rotwildvorkommen anhand morphologischer Geweihmerkmale erlegter Hirsche als Fortsetzung die Merkmale von Abwurfstangen zur Grundlage, mit welchen ein breiteres Spektrum der Geweihbildung erfaßt werden kann. An insgesamt 418 Abwurfstangen aus vier ungarischen Rotwildgebieten wurden jeweils 14 morphologische Parameter aufgenommen. Zur Charakterisierung der Massenverteilung an der Abwurfstange wurde der „Stangenschwerpunkt“ als neuer Parameter eingeführt. Die zwischen den Abwurfstangenmerkmalen bestehenden Zusammenhänge wurden einheitlich in definierten Grenzbereichen mit Hilfe der einfachen Korrelations- und Regressionsrechnung sowie der Faktorenanalyse, die Unterschiede zwischen den Einzelpopulationen mit der Methode der stufenweisen Diskriminanzanalyse untersucht. In zahlreichen Fällen konnten enge positive Korrelationen zwischen den Einzelmerkmalen nachgewiesen werden. So zum Beispiel bei den ausgewählten Parameterpaaren; Stangenmasse und Stangenlänge (r=0,84–0,92), unterer Stangenumfang und Stangenlänge (r=0,79–0,87) sowie oberer Stangenumfang und Stangenmasse (r=0,86–0,95). Ein Vergleich der Populationen auf Grundlage der zwischen den Parameterpaaren bestehenden Zusammenhänge erbrachte nur geringe Unterschiede. Die Faktorenanalyse zeigte, daß die Formenvariabilität der Abwurfstangen durch die Merkmale der unteren und der oberen Stangenmasse sowie durch das Verhältnis der beiden, den Stangenschwerpunkt charakterisiert werden kann. Im Ergebnis der Diskriminanzanalyse konnten im untersuchten Massebereich (0,3≤x≤3,0 kg) zum Teil zwischen den einzelnen Populationen signifikante Unterschiede ermittelt werden, welche jedoch gering waren. Unter den sechs die Untersuchungsgebiete abgrenzenden Merkmalen war auch der Stangenschwerpunkt vertreten. Die einzelnen Abwurfstangen wurden in durchschnittlich 50 % der Fälle richtig ihren eigentlichen Herkunftsgebieten zugeordnet. Charakteristische Geweihtypen konnten nicht nachgewiesen werden. Es werden die Ergebnisse der Geweih- und der Abwurfstangenuntersuchungen erörtert. Weitere Wege der vergleichenden Betrachtung zwischen Rotwildpopulationen werden aufgezeigt, wobei die komplexe Untersuchung morphologischer und biochemisch-genetischer Merkmale hervorgehoben wird.
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    European journal of wildlife research 35 (1989), S. 235-244 
    ISSN: 1439-0574
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Description / Table of Contents: Summary The present paper is concerned with research carried out in the Emmental area in Switzerland in a selection forest of the silver fir-beech typ(Abieti-Fagetum). The basis was a random survey, assessing density and browsing intensity for each species of the young forest trees. A total of 199 random samplings were taken, distributed systematically over 176 ha and comprising 30 young forest trees each. A regression and correlation analysis of the data showed that, on small browsing areas, browsing intensity of a specific tree species is highly influenced by the availability of any other browse plants. If beech and spruce are numerous, silver fir is subjected to increased browsing. On the other hand, a high density of silver fir can effectively ease the strain of browsing on both beech and spruce. A reduction of the browse impact on all tree species can be achieved by a high supply of sycamore maple, common ash, and mountain ash. Browsing by roe deer has now reached such proportions in the area investigated that silver fir suffers heavy losses through mortal browsing. The subsequent steady decline in the number of silver fir is further accelerated by the continued shift of the browse supply to beech and spruce.
    Abstract: Résumé La présente étude a été réalisée dans une forêt jardinée de l'Emmental (Suisse) sise dans le domaine de la hêtraie à sapins(Abieti-Fagetum). Les données de base ont été fournies à l'aide d'un relevé par échantillonnage, pour chaque essence, de la densité et de l'intensité de l'abroutissement sur de jeunes arbres forestiers. Il s'agit au total de 199 placettes réparties systématiquement sur 176 ha et contenant chacune 30 jeunes plantes. A l'aide d'une analyse de régression et de corrélation, la preuve a été faite que sur de petites surfaces de gagnage, l'intensité de l'abroutissement d'une essence donnée est fortement influencée par la quantité et la qualité des autres plantes susceptibles d'être abrouties. Une quantité importante de hêtres et d'épicéas induit un abroutissement plus intense du sapin blanc. Inversément, une forte densité de sapins blancs peut soulager efficacement de l'abroutissement tant le hêtre que l'épicéa. Une forte présence de l'érable de montagne, du frêne et du sorbier des oiseleurs provoque une diminution de la pression de l'abroutissement sur l'ensemble des essences. L'abroutissement du chevreuil atteint actuellement, pour la région étudiée, une proportion élevée qui a pour conséquence d'importantes défections dues à l'abroutissement létal. La régression continue du sapin blanc ainsi provoquée est de plus accélérée par le déplacement persistant de la proportion des essences au profit du hêtre et de l'épicéa.
    Notes: Zusammenfassung Die vorliegende Untersuchung wurde im Emmental (Schweiz) in einem Plenterwaldgebiet des Tannen-Buchenwaldes(Abieti-Fagetum) ausgeführt. Die Grundlage dazu lieferte eine Stichprobenerhebung, mit der baumartenweise die Dichte und Verbißintensität der jungen Waldbäume erfaßt worden waren. Insgesamt handelte es sich um 199, systematisch über 176 ha verteilte Stichproben zu je 30 jungen Waldbäumen. Mit Hilfe einer Regressions- und Korrelationsanalyse konnte der Nachweis erbracht werden, daß auf kleinen Äsungsflächen die Verbißintensität einer bestimmten Baumart vom Angebot der übrigen Verbißpflanzen erheblich beeinflußt wird. Ein hohes Angebot von Buche und Fichte zieht einen verstärkten Verbiß der Weißtanne nach sich. Umgekehrt kann eine hohe Dichte der Weißtanne sowohl die Buche als auch die Fichte wirkungsvoll vom Verbiß entlasten. Ein hohes Angebot von Bergahorn, Esche und Vogelbeere bewirkt bei sämtlichen Baumarten eine Verminderung der Verbißbelastung. Der Verbiß durch das Reh erreicht gegenwärtig im Untersuchungsgebiet einen Wert, der bei der Weißtanne hohe Abgänge durch Totverbiß zur Folge hat. Der dadurch ausgelöste stetige Rückgang der Weißtanne wird durch die anhaltende Verlagerung des Angebotes auf Buche und Fichte zusätzlich beschleunigt.
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    European journal of wildlife research 35 (1989), S. 252-256 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Description / Table of Contents: Summary Presented is a case of periodontitis apicalis purulenta in the mandible of a roe buck, aged 16 to 18 months. The anomaly was caused by a 90 degrees rotation of the right P4 and the resulting failure to resorb the distal root of the right Pd4, which was not shed. In the course of the resorption of its mesial root the pulpal cavity of the Pd4 was exposed and invaded by bacteria. Through the apical foramen of the tooth's distal root the inflammation later extended into the periapical space.
    Abstract: Résumé Sont décrites les altérations pathologiques résultant d'un abcès périapical(Parodontitis apicalis purulenta) au niveau du rumen inférieur droit du maxillaire d'un brocard de 16 à 18 mois. L'altération résulte d'une rotation à 90° de la P4 par rapport à sa position normale dans le maxillaire et l'absence consécutive de résorption de la racine distale de la Pd4 restée en place. Lors de l'évacuation de la dent de lait, la cavité pulpaire de cette dent, en s'ouvrant, donne accès à une infection bactérienne. L'inflammation gagne ensuite l'espace périapical par leForamen apicale de la racine distale de la Pd4.
    Notes: Zusammenfassung Beschrieben werden die als Folge eines periapicalen Abszesses (Parodontitis apicalis purulenta) entstandenen pathologischen Veränderungen in der rechten Unterkieferhälfte eines 16 bis 18 Monate alten Rehbockes. Ursache der Erkrankung war die Rotation des P4 um 90 Grad gegenüber seiner normalen Position im Kiefer und das daraus resultierende Ausbleiben der Resorption der distalen Wurzel des stehengebliebenen Pd4. Im Zuge des Milchzahnabbaues erfolgte die Eröffnung der Pulpahöhle dieses Zahnes, in die anschließend bakterielle Infektionserreger eindrangen. Später dehnte sich der Entzündungsprozeß dann über das Foramen apicale der distalen Wurzel des Pd4 auf den periapicalen Raum aus.
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    European journal of wildlife research 35 (1989), S. 271-279 
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    European journal of wildlife research 35 (1989), S. 280-280 
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    Stochastic environmental research and risk assessment 3 (1989), S. 1-16 
    ISSN: 1436-3259
    Keywords: Width function ; instantaneous unit hydrograph ; peak ; regression ; birth-death process
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract We investigate optimal predictors of the peak (S) and distance to peak (T) of the width function of drainage networks under the assumption that the networks are topologically random with independent and exponentially distributed link lengths. Analytical results are derived using the fact that, under these assumptions, the width function is a homogeneous Markov birth-death process. In particular, exact expressions are derived for the asymptotic conditional expectations ofS andT given network magnitudeN and given mainstream lengthH. In addition, a simulation study is performed to examine various predictors ofS andT, includingN, H, and basin morphometric properties; non-asymptotic conditional expectations and variances are estimated. The best single predictor ofS isN, ofT isH, and of the scaled peak (S divided by the area under the width function) isH. Finally, expressions tested on a set of drainage basins from the state of Wyoming perform reasonably well in predictingS andT despite probable violations of the original assumptions.
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    Stochastic environmental research and risk assessment 3 (1989), S. 68-69 
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    Stochastic environmental research and risk assessment 3 (1989), S. 281-292 
    ISSN: 1436-3259
    Keywords: Generalised Pareto distribution ; Peaks over threshold ; Probability weighted moments ; Regionalisation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract A peaks over threshold (POT) method of analysing daily rainfall values is developed using a Poisson process of occurrences and a generalised Pareto distribution (GPD) for the exceedances. The parameters of the GPD are estimated by the method of probability weighted moments (PWM) and a method of combining the individual estimates to define a regional curve is proposed.
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    Stochastic environmental research and risk assessment 3 (1989), S. 31-49 
    ISSN: 1436-3259
    Keywords: Reservoir operation ; prediction ; Kalman filtering ; flood prevention ; fuzzy control
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract Japan has traditionally performed flood prevention through the construction and use of dikes, storage reservoirs, and basins which are costly and time consuming options. Another non-structural option is to operate the flood control system appropriately with a view to reducing flood damage. In this paper, a flood control system combining the runoff prediction model in the whole river basin with the reservoir operation is discussed. Different models of the runoff process are introduced in order to compare their accuracies and the computational time for the flood forecasting system. The reservoir operational rule is formulated in terms of fuzzy inference theory. Historical data are applied in a case study for verification of the proposed theories.
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    Stochastic environmental research and risk assessment 3 (1989), S. 69-69 
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    Stochastic environmental research and risk assessment 3 (1989), S. 154-154 
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    Stochastic environmental research and risk assessment 3 (1989), S. 155-178 
    ISSN: 1436-3259
    Keywords: Stochastic differential equations ; Stochastic Taylor formula ; Numerical methods ; Simulations ; Strong convergence ; Weak convergence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract The development of numerical methods for stochastic differential equations has intensified over the past decade. The earliest methods were usually heuristic adaptations of deterministic methods, but were found to have limited accuracy regardless of the order of the original scheme. A stochastic counterpart of the Taylor formula now provides a framework for the systematic investigation of numerical methods for stochastic differential equations. It suggests numerical schemes, which involve multiple stochastic integrals, of higher order of convergence. We shall survey the literature on these and on the earlier schemes in this paper. Our discussion will focus on diffusion processes, but we shall also indicate the extensions needed to handle processes with jump components. In particular, we shall classify the schemes according to strong or weak convergence criteria, depending on whether the approximation of the sample paths or of the probability distribution is of main interest.
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    Stochastic environmental research and risk assessment 3 (1989), S. 217-226 
    ISSN: 1436-3259
    Keywords: Stochastic integral equation method ; rainfall-runoff models ; confidence interval
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract The stochastic integral equation method (S.I.E.M.) is used to evaluate the relative performance of a set of both calibrated and uncalibrated rainfall-runoff models with respect to prediction errors. The S.I.E.M. is also used to estimate confidence (prediction) interval values of a runoff criterion variable, given a prescribed rainfall-runoff model, and a similarity measure used to condition the storms that are utilized for model calibration purposes. Because of the increasing attention given to the issue of uncertainty in rainfall-runoff modeling estimates, the S.I.E.M. provides a promising tool for the hydrologist to consider in both research and design.
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    Stochastic environmental research and risk assessment 3 (1989), S. 241-260 
    ISSN: 1436-3259
    Keywords: Hat matrix ; Mahalanobis distance ; Additive outliers ; Innovation outliers ; Influential data ; Autoregressive models ; Threshold autoregression ; Lake Huron
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract A practical method is developed for outlier detection in autoregressive modelling. It has the interpretation of a Mahalanobis distance function and requires minimal additional computation once a model is fitted. It can be of use to detect both innovation outliers and additive outliers. Both simulated data and real data re used for illustration, including one data set from water resources.
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  • 56
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    Stochastic environmental research and risk assessment 3 (1989), S. 293-316 
    ISSN: 1436-3259
    Keywords: Confined aquifer ; Transmissivity identification ; Geostatistics ; Inverse problem ; Ill-posedness ; Ill-conditioning ; Stability analysis ; Regularization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract In recent years, geostatistical concepts have been applied to the inverse problem of transmissivity estimation from piezometric head data. It has been claimed that such methods overcome various difficulties encountered in other approaches. However, the reconstruction of transmissivity from head measurements is ill-posed as it depends on derivatives of the head field. Consequently, any accurate method for its solution is likely to encounter numerically ill-conditioned systems. This paper reviews the geostatistical approach, and uses the stability analyses of linear algebra to show that, as the amount of available data increases and the discretization of the system is refined, both a numerically ill-conditioned parameter estimation problem and ill-conditioned cokriging equations may appear. Therefore, while the geostatistical approach does have conceptual appeal, it does not avoid the fundamental difficulties arising out of the ill-posed nature of transmissivity identification. Instead, the method is likely to be quite sensitive to these difficulties, so care must be taken in its formulation to minimize their effects. A means to stabilize the geostatistical method is suggested and numerical experiments that highlight key points of our analysis are given.
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  • 57
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    European journal of nutrition 28 (1989), S. 56-75 
    ISSN: 1436-6215
    Keywords: free radicals ; cataracts ; antioxidant vitamins ; vitamin C ; vitamin E ; β-carotene ; Katarakte ; antioxidative Vitamine ; Vitamin C und E ; Betakarotin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Die Augenlinse kann durch einfallendes Licht und Sauerstoff photooxidativ so geschädigt werden, daß eine Trübung bzw. ein Katarakt entsteht. Sauerstoffradikale schädigen nicht nur die Kristalline, spezialisierte Linsenproteine, die Aggregate bilden und präzipitieren, sondern sie greifen auch proteolytische Enzyme an, deren Funktion es wäre, die geschädigten Proteine zu eliminieren. Neben einem enzymatischen Abwehrsystem gegen Sauerstoffradikale, bestehend aus Superoxiddismutase, Katalase und Glutathionperoxidase, enthält die Linse die antioxidativen Vitamine C und E und evtl. Betakarotin. Tierversuche an verschiedenen Spezies haben sowohl in vitro als auch in vivo eine Schutzwirkung gegen lichtinduzierte Kataraktbildung aufgezeigt. Eine ähnliche Wirkung war gegen Zucker- und Steroidkatarakte nachweisbar. Epidemiologische Studien am Menschen haben gezeigt, daß Personen mit vergleichsweise höherer Einnahme bzw. höheren Blutkonzentrationen antioxidativer Vitamine ein vermindertes Risiko der Kataraktbildung haben. Diese positiven Befunde rechtfertigen die Durchführung breit angelegter Interventionsstudien mit antioxidativen Vitaminen am Menschen.
    Notes: Summary The ocular lens, which is continually exposed to light and ambient oxygen, is at high risk of photooxidative damage resulting in cataract. Oxygen free radicals appear to impair not only lens crystallins which will aggregate and precipitate forming opacities but also proteolytic enzymes whose function it would be to eliminate the damaged proteins. Apart from an enzymatic defense system consisting of superoxide dismutase, catalase and glutathione peroxidase against excited oxygen species the lens contains the antioxidant vitamins C, E and presumably β-carotene as another line of defense. In vitro and in vivo studies in different animal species have demonstrated a significant protective effect of vitamins C and E against light-induced cataract. Sugar and steroid cataracts were prevented as well. Epidemiological evidence in humans suggests that persons with comparatively higher intakes or blood concentrations of antioxidant vitamins are at a reduced risk of cataract development. These positive findings established by several research groups justify extensive intervention trials with antioxidant vitamins in humans using presenile cataract development as a model.
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    European journal of nutrition 28 (1989), S. 103-129 
    ISSN: 1436-6215
    Keywords: geeignete Spezies ; analoge Reaktionen ; optimale Standardisierung ; ethische Grundsätze ; spezifische Alternativen ; suitablespecies ; analogousreactions ; optimalstandardization ; ethicalprinciples ; specificalternatives
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary Experimental animals may serve as models for human beings, if analogies between animal and human functions exist. Therefore, the selection of species and strain plays an important role in the development of such models. Knowledge of the nutritional and physiological characteristics of a species is a prerequisite for the composition of complete diets. Often, preliminary work has to begin at the breeding farm in order to make use of such curative models possible. Only when the high requirements of standardization of experimental animals are met can clinical and subclinical symptoms be determined distinctly. By means of sensitive biochemical reactions, imbalances and interactions of nutritive and active ingredients, as well as successful substitutions, can be recorded. The study of absorption and metabolism of preparations is made possible by observing these reactions. However, negative influence on the results of analysis must be eliminated by correct selection of narcotics, and the proper excision and storage of organs. Because of its importance for the planning and evaluation of experiments, biometry is an integral part of every research project. The scientific information which must be gained from the whole experimental animal cannot be substituted by either isolated organs and cell cultures, or by means of computer simulation. A demanding effort, which includes biotechnological methods, is necessary to further reduce the number of experimental animals and, simultaneously, to enhance experimental evidence. In any case, all scientific aims must be in accordance with the ethical principles of the Society for the Prevention of Cruelty to Animals.
    Notes: Zusammenfassung Versuchstiere können als Modell für den Menschen herangezogen werden, wenn Analogien zwischen tierischen und menschlichen Funktionen bestehen. Deshalb kommt der Wahl von Spezies und Stamm bei der Entwicklung solcher Modelle eine besondere Bedeutung zu. Die Kenntnis der ernährungsphysiologischen Besonderheiten einer Spezies ist die Voraussetzung für die Herstellung vollwertiger Diäten. Oft sind Vorleistungen bereits in der Zuchtstation zu erbringen, um kurative Modelle überhaupt erst anwenden zu können. Nur wenn die hohen Anforderungen an die Standardisierung des tierexperimentellen Teiles einer Untersuchung erfüllt sind, können klinische und subklinische Symptome eindeutig zugeordnet werden. Mit empfindlichen biochemischen Reaktionen lassen sich sowohl Imbalanzen und Interaktionen von Nähr- und Wirkstoffen sowie Substitutionserfolge erfassen. Ebenso können die Resorption und der Stoffwechsel von Präparaten verfolgt werden. Negative Auswirkungen auf das Analysenergebnis sind bereits bei der Wahl des Narkotikums, der Entnahme und Lagerung von Organproben auszuschließen. Wegen ihrer Bedeutung für die Planung und Auswertung stellt auch die Biometrie einen integrierenden Bestandteil eines jeden Forschungsprojektes dar. Die am Ganztier erzielte wissenschaftliche Information kann weder mit isolierten Organen und Zellkulturen, noch mit Hilfe simulierender Computersysteme erreicht werden. Große Anstrengungen, auch unter Einbeziehung biotechnologischer Methoden, sind erforderlich, um die Tierzahlen weiterhin zu reduzieren und gleichzeitig die Aussagekraft der Experimente zu erhöhen. In jedem Fall jedoch müssen die wissenschaftlichen Zielsetzungen mit den ethischen Anliegen des Tierschutzes in Einklang gebracht werden.
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  • 59
    ISSN: 1436-6215
    Keywords: Fettemulsion ; MCT ; LCT ; Lipoproteine ; Elimination ; fat emulsion ; triglycerides ; medium chain (MCT) triglycerides ; long chain (LCT) ; lipoprotein elimination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary A fat emulsion containing 20% fat as medium chain triglycerides (MCT) and long chain triglycerides (LCT) (1∶1) was injected as a bolus in an amount of 0.2 g fat per kg body weight to six patients, three to five days after a serious injury. Triglyceride concentrations increased within two min in lipoprotein fractions d〈0.95 g/ml (Chylomicrons), d〈1.006 g/ml (VLDL), d〈1.063 g/ml (LDL) and d〈1.21 g/ml (HDL). Sixty minutes after injection triglyceride concentrations had again reached preexperimental values in all lipoprotein fractions. Cholesterol values did not change. According to the composition of the fat emulsion, linoleic acid content increased in triglycerides of all lipoprotein fractions, whereas octanoic and decanoic acid did so only in triglyceride-rich lipoproteins (d〈1.006). Half-life values of elimination of octanoic acid (3.3 min) and decanoic acid (3.9 min) in triglycerides of lipoprotein fraction d〈1.006 were nearly half as short as that of long chain fatty acids (linoleic acid, 6.4 min; oleic acid, 6.5 min; palmitic acid, 7.5 min). Thus in contrast to LCT, MCT are only found in triglyceride-rich lipoproteins (d〈1.006) and are also eliminated more rapidly.
    Notes: Zusammenfassung Eine Fettemulsion mit 20% Fett aus mittelkettigen Triglyceriden (MCT) und langkettigen Triglyceriden (LCT) (1∶1) wurde als Bolus in einer Menge von 0,2 g Fett pro kg Körpergewicht bei 6 Patienten 3–5 Tage nach einem schweren Unfall injiziert. Die Triglyceridkonzentrationen stiegen innerhalb von 2 Minuten in den Lipoproteinfraktionen d〈0,95 g/ml (Chylomikronen), d〈1,006 g/ ml (VLDL), d〈1,063 g/ml (LDL) und d〈1,21 g/ml (HDL) an. 60 Minuten nach der Injektion hatten die Triglyceridkonzentrationen bereits wieder in allen Lipoproteinfraktionen dsie Vorwerte erreicht. Die Cholesterinkonzentrationen änderten sich nicht. Entsprechend der Zusammensetzung der Fettemulsion nahm der Linolsäureanteil in den Triglyceriden aller Lipoproteinfraktionen zu, während Octansäure und Decansäure nur in den triglyceridreichen Lipoproteinen (d〈1,006) anstiegen. Die Halbwertszeiten der Elimination der Octansäure (3,3 min) und Decansäure (3,9 min) in den Triglyceriden der Lipoproteinfraktion d〈1,006 waren fast halb so kurz wie die der langkettigen Fettsäuren (Linolsäure, 6,4 min; Ölsäure, 6,5 min; Palmitinsäure, 7,5 min). Demzufolge findet man im Gegensatz zu den LCT die MCT nur in den triglyceridreichen Lipoproteinen (d〈1,006), und sie werden daraus auch rascher eliminiert.
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  • 60
    ISSN: 1436-6215
    Keywords: RBP secretion ; vitamin A ; carotenoids ; goat ; RBP-Sekretion ; Vitamin A ; Carotinoide ; Ziege
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Die Sekretion von retinolbindendem Protein (RBP) ins Blut von Ziegen wurde nach unterschiedlicher Verabreichung von Vitamin A (Retinylacetat), Β-Carotin und einer Mischung von pflanzlichen Carotinoiden untersucht. Die Zufuhr dieser Verbindungen — entweder in einer einzelnen hohen Dosis oder in der gleichen Menge gleichmäßig auf 4 Tagesdosen verteilt — führte zu einem deutlichen Anstieg der RBP-Sekretion. Diese Sekretion erfolgte in zwei Phasen, von denen eine früh und eine später einsetzte.
    Notes: Summary Studies were conducted on the secretion of retinol-binding protein (RBP) in blood of goats given different treatments of preformed vitamin A, Β-carotene and plant carotenoids. Administration of these sources either in a single massive dose or massive dose split into four equal doses, markedly increased the secretion of RBP in blood. The secretion of RBP in blood occurred at least in two phases, one at early periods and the other at later periods.
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    European journal of nutrition 28 (1989), S. 265-265 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
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    European journal of nutrition 28 (1989), S. 300-309 
    ISSN: 1436-6215
    Keywords: tobacco protein ; Arnes test ; micronucleus test ; chromosome aberration test ; SCE test ; Tabakprotein ; Ames-Test ; Mikrokerntest ; Chromosomenaberrationstest ; Schwesterstrangaustauschtest
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Tabakprotein wurde im Ames-Test und in drei In-vivo-Tests auf Mutagenität geprüft. In den Salmonellenstämmen TA 98 und TA 100 bewirkten Methanolextrakte des Tabakproteins und der Urin von Ratten, die mit Tabakprotein gefüttert waren, erhöhte Revertantenzahlen, nicht aber Fäzesextrakte. Im Mikrokerntest wurden durchgehend schwach positive Effekte des Tabakproteins in Chinesischen Hamstern und zwei Mäuse-Inzuchtstämmen erzielt, desgleichen im Chromosomenaberrationstest und im SCE-Test an Chinesischen Hamstern. Die in den analytischen Angaben des Tabakproteins ausgewiesenen Substanzen Nikotin, Chlorogensäure und Rutin wurden einzeln im Chromosomenaberrationstest geprüft. Dabei wurde das Nikotin als der verantwortliche Faktor oder einer der verantwortlichen Faktoren für die schwach positiven Testergebnisse erkannt.
    Notes: Summary Tobacco protein was assayed for mutagenicity using the Ames test and three in vivo tests. In the Salmonella strains TA 98 and TA 100 methanolic extracts of the tobacco protein and urine of rats fed tobacco protein exhibited increased revertant numbers, but extracts of feces did not. Using the micronucleus test throughout, weak mutagenic effects after feeding the tobacco protein were detected in Chinese hamsters and two inbred strains of mice, and again in Chinese hamsters when the chromosome aberration test and the SCE test were applied. The analytical specifications of the tobacco protein listed nicotine, chlorogenic acid and rutin as components. These were examined separately in a chromosome aberration test, and nicotine was discovered to be the factor or a factor responsible for the weak positive test results.
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    European journal of nutrition 28 (1989), S. 319-326 
    ISSN: 1436-6215
    Keywords: Tryptophanschädigung ; Tryptophangehalt im Brot ; Tryptophangehalt im Keks ; tryptophan degradation ; tryptophan content inbread ; tryptophan content incookie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary The change of tryptophan contents in proteins of bread and cookies under technological processing conditions were investigated. Tryptophan contents in all cookie samples were noted to be significantly (p=0.05) reduced in relation to corresponding dough. The relative decreases are significantly correlated with fat content and the degree of unsaturation of fats in the dough of cookies (r=0.802 and r=0.777, p=0.01), independently of various physical parameters during different cookie samples' processing. Tryptophan decrease in proteins of bread during baking was not significant.
    Notes: Zusammenfassung Es wurde der Einfluß des technologischen Herstellungsprozesses auf die Gehaltsveränderung von Tryptophan in Brot- und Kekseiweißen untersucht. Es wurde eine signifikante (p=0,05) Tryptophanabnahme bei dem Backen der verschiedenen Keksarten festgestellt. Diese Abnahme korreliert linear mit dem Lipidgehalt und dem Gehalt an ungesättigten Fettsäuren der entsprechenden Keksteige (r=0,802 bzw. r=0,777 bei p=0,01), unabhängig von bedeutenden Schwankungen der physikalischen Parameter im Produktionsprozeß der verschiedenen Keksarten. Bei Brot blieb der Tryptophangehalt während des Backens praktisch unverändert.
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    European journal of nutrition 28 (1989), S. 345-345 
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    European journal of nutrition 17 (1978), S. 124-127 
    ISSN: 1436-6215
    Source: Springer Online Journal Archives 1860-2000
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    European journal of nutrition 17 (1978), S. 129-139 
    ISSN: 1436-6215
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary Since most of the drugs are taken orally via the gastrointestinal tract, interactions with food ingredients may lead to alterations in the intake of essential dietary factors. With regard to vitamins the following effects have been demonstrated: early decomposition resp. inactivation, decreased absorption or a qualitatively and quantitatively modified metabolism. Examples of such changes are given with regard to water- and lipid-soluble vitamins.
    Notes: Zusammenfassung Arzneimittel werden meistens peroral, d. h. über den Magen-Darm-Kanal, zugeführt. Damit besteht die Möglichkeit einer Interaktion mit Nahrungsinhaltsstoffen, die aber dann bedeutsam sein dürfte, wenn essentielle Nahrungsfaktoren wie z. B. Vitamine betroffen sind. Für die Vitamine können sich dann folgende Auswirkungen ergeben: eine vorzeitige Zerstörung bzw. Inaktivierung, eine gehemmte Resorption aus dem Magen-Darm-Kanal oder eine quantitativ und qualitativ veränderte Metabolisierung. Anhand von Beispielen werden derartige Auswirkungen von Arzneimitteln auf wasserlösliche und fettlösliche Vitamine aufgezeigt.
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    European journal of nutrition 17 (1978), S. 112-123 
    ISSN: 1436-6215
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary Mould cultures are used for the manufacture of soft and blue cheese. The report deals with the present stage of knowledge of the question of mycotoxin-producers in mould cultures used for cheesemaking. The PR-toxin was isolated repeatedly fromPenicillium roqueforti strains which were incubated on special media, but also from P. roqueforti cultures used for cheese manufacture. However, cheese ripening conditions do not favow the production of this toxin. Other catabolites from P. roqueforti such als roquefortine and isofumigaclavine have been found in cheese, but there is not much known about their toxic effect. No cancerogenic mycotoxins have been discovered in these types of cheese, except aflatoxin M1 which might however originate from contaminated milk. It must be concluded that the occurrence of tumors after feeding of a pureP. camemberti var. candidum culture is due to the effect of mycotoxins. On the other hand, further animal experiments with various mould culture strains used for cheesemaking have not confirmed these findings. On the basis of the literature consulted it may be said that the use of mould cultures for cheesemaking does not involve any risk for human health, that means it is toxicologically harmless.
    Notes: Zusammenfassung Schimmelpilzkulturen werden bei der Herstellung von Weißschimmel— und Blauschimmelkäse verwendet. Es wird über den gegenwärtigen Stand der Kenntnisse zur Frage von Mykotoxinbildnern in Schimmelpilzkulturen der Käsefabrikation berichtet. Verschiedentlich wurde ausPenicillium roqueforti-Stämmen, die auf speziellen Medien bebrütet wurden, das PR-Toxin isoliert, auch aus P. roqueforti-Kulturen, die zur Käseherstellung verwendet werden. Doch sind die Bedingungen der Käsereifung für eine Produktion dieses Toxins nicht geeignet. Weitere Stoffwechselprodukte von P. roqueforti wie Roquefortin und Isofumigaclavin konnten in Käse aufgefunden werden, doch ist über deren toxische Wirkung wenig bekannt. Kanzerogen wirkende Mykotoxine konnten in Schimmelkäsen nicht gefunden werden, außer Aflatoxin M1, das jedoch aus der kontaminierten Milch stammen dürfte. Das Auftreten von Tumoren nach Verfütterung einer Reinkultur vonP. camemberti var. candidum ließ auf eine Mykotoxinwirkung schließen. Doch haben weitere Tierversuche mit verschiedenen, bei der Käsefabrikation verwendeten Schimmelpilzstämmen diesen Befund nicht bestätigt. Es läßt sich aufgrund der gesichteten Literatur sagen, daß der Einsatz von Schimmelpilzkulturen in der Käsefabrikation kein Risiko für den Menschen darstellt, also toxikologisch unbedenklich ist.
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    ISSN: 1436-6215
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary After the 24 hours preoperative infusion period 0.37% glucose, 0.05% fruc tose and 1.28%xylitol of the infused amount were excreted in the urine. Postoperatively fructose was the best metabolized energy donator before xylitol and glucose. As a sign of an undisturbed hepatic synthesis of lipoproteins the triglycerides rose up to the 5th postoperative day. During the parenteral nutrition and the additional surgical intervention the cholesterol fell from 192.3 to 128.5 mg/100 ml on the first postoperative day. The infusion solutions caused a rise of the insulin concentration from 23.2 to 46.3 U/1 on the operation day. There is a positive nitrogen balance of 3.5 g/24 h on the operation day. The slight negative balance of −1.15 g/24 h on the first postoperative day is reduced to − 0.61 g/24 h on the postoperative day. The changes of the enzymes LDH, GOT and AP were at normal range. The postoperative changes were due to the surgical intervention. Without a simultaneous change of enzymes, 5 patients had a rise of bilirubin up to 1.1 mg/100 ml. To avoid a too great loos of phosphate during a long-term parenteral nutrition period, it is important to put up a balance.
    Notes: Zusammenfassung Nach 24stündiger präoperativer Infusionsperiode werden von der infundierten Menge 0,37% Glukose, 0,05% Fruktose und 1,28% Xylit im 24-h-Urin ausgeschieden. Postoperativ erweist sich Fruktose vor Xylit und Glukose als der am besten verwertete Energieträger. Als Zeichen einer ungestörten hepatischen Lipoproteinsynthese steigen die Triglyzeride bis zum 5. postoperativen Tag an. Unter der parenteralen Ernährung und durch den zusätzlichen operativen Eingriff erfolgt ein starker Cholesterinabfall von 192,3 auf 128,5 g/100 ml am 1. postoperativen Tag. Durch die Infusionslösungen steigt die Insulinkonzentration von 23,2 auf 46,3 U/1 am Operationstag an. Postoperativ werden erhöhte Insulinwerte gemessen. Die Harnsäurekonzentration fällt bis zum unteren Normbereich ab. Am Operationstag besteht eine positive N-Bilanz von 3,5 g/24 h. Die leicht negative Bilanz von −1,15 g/24 h am 1. postoperativen Tag geht bis zum 4. postoperativen Tag auf −0,61 g/24 h zurück. Die Veränderungen der gemessenen Enzyme LDH, GOT und AP bewegen sich im Normbereich. Die postoperativen Veränderungen sind auf den operativen Eingriff zurückzuführen. Ohne entsprechende Enzymveränderungen erfolgt bei 5 Patienten ein Anstieg der Bilirubinkonzentration auf 1,25 mg/100 ml. Um zu große endogene Phosphatverluste bei längerfristiger parenteraler Ernährung zu vermeiden, ist es notwendig, eine Bilanz aufzustellen.
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    European journal of nutrition 28 (1989), S. 263-264 
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    European journal of nutrition 28 (1989), S. 240-259 
    ISSN: 1436-6215
    Keywords: Data analysis ; health status ; food pattern ; nutrition behavior ; research strategy ; Gesundheitsstatus ; Ernährungsverhalten ; Forschungsstrategie ; Datenanalyse ; Nahrungsmuster ; Ernährungsepidemiologie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Die Beziehungen zwischen Ernährungsfaktoren und Gesundheit in epidemiologischen Studien sind oft inkonsistent. Eine der möglichen Ursachen für diese Gegebenheit kann darin liegen, daß die Vielzahl der potentiellen Ernährungsdimensionen in der spezifischen Untersuchungssituation in unzulänglichem Maße berücksichtigt wurden. Solche Dimensionsbereiche sind vor allem die physiologische Individualität von Menschen, deren verschiedenen Lebensumwelten und die zahlreichen Interdependenzen zwischen Ernährungsvariablen. Diese Tatsachen sollten in ernährungsepidemiologischen Studien dadurch besser erfaßt werden, daß sowohl die Studienmodelle als auch die Datenanalysen entsprechend ausgerichtet werden. Anstelle von Untersuchungen an heterogenen Stichproben ist es ratsam, sich auf spezifische „Typen“ zu konzentrieren, wobei gemäß dem jeweiligen Studienziel solche „Typen“ aus den physiologischen Besonderheiten (z. B. Cholesterinempfindlichkeit), aus biologisch-konstitutionellen Faktoren (z. B. Körperbau-Typus), aus Lebensstil-Eigenschaften oder anderen Faktorenbereichen abgeleitet werden können. Die Variationsbreite der Ernährungsfaktoren geht über die üblicherweise verwendeten Nährstoffdimensionen hinaus, doch sie läßt sich durch integrierte Indizes — die „Nahrungsmuster“ — zusammenfassen. Zu solchen „Nahrungsmustern“ kann man auf verschiedene Weise kommen. Sie können aus Theorien abgeleitet werden und zu bestimmten Bewertungsrastern führen. Man kann sie aber auch mittels multivariater statistischer Analyse suchen. Die prinzipiellen Wege, die zu „Nahrungsmustern“ führen, werden dargestellt und diskutiert. Die hier vorgestellten und diskutierten Ideen leiten zu einem verbesserten Untersuchungsmodell für ernährungsepidemiologische Studien über. Die „Nahrungsmuster“ nehmen dabei eine wichtige Position ein. Man kann annehmen, daß durch diesen Untersuchungsansatz neue Erkenntnisse über die Beziehungen zwischen Ernährung und Gesundheit sichtbar werden, die helfen, den bisher noch diffusen Untersuchungsbereichen klare Konturen zu geben.
    Notes: Summary The relation between nutritional factors and health investigated in epidemiological studies are often inconsistent. One of the reasons for such findings can be the improper addressing of the multitude of nutritional dimensions in the specific study situation such as physiological individuality of human beings, different living conditions, or numerous interdependencies between nutritional variables. Epidemiological research in nutrition and health should recognize such facts and work with appropiate study models and adequate data analyses. Instead of investigating heterogenous populations it is advisable to concentrate on specific “types” of people. Under consideration of the study goals such “types” can be compiled according to physiological properties, e.g., cholesterol sensitivity, or biological-constitutional factors such as body build, life-style entities, or other factors. The variety of nutrition factors far beyond the commonly applied nutrient values can be expressed in integrated indices of “food patterns”. Such “food patterns” can be derived in many ways. They can be deduced from theories by using specific criteria, but also explored by modern multivariate statistical analyses. The ways leading to “food patterns” are discussed. The ideas presented and discussed in this paper lead to an improved model for research in the field of nutrition and health with integrated indices of “food patterns” as the critical point. It is assumed that using this approach will generate new insight in the relation of nutrition and health, a currently still diffuse research area.
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  • 71
    ISSN: 1436-6215
    Keywords: dietarycalcium ; dietarymagnesium ; dietaryphosphorus ; serumcholesterol ; livercholesterol ; fecalbile acids ; rats ; Calcium ; Magnesium ; Phosphor ; Serumcholesterin ; Lebercholesterin ; Gallensäure im Kot ; Ratten
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Während 28 Tagen wurden an Ratten cholesterinfreie halbgereinigte Diäten, die verschiedene Konzentrationen von Calcium (0,13–0,75 g/100 g), Magnesium (0,02–0,04 g/100 g) oder Phosphor (0,2–0,8 g/100 g) enthielten, verabreicht. Die unterschiedlichen Mineralkonzentrationen hatten keinen Einfluß auf Serum- und Lebercholesterin oder die Ausscheidung von Gallensäuren im Kot.
    Notes: Summary Female rats were fed cholesterol-free, purified diets with different concentrations of calcium (0.13–0.75%, w/w), magnesium (0.02 or 0.04%) or phosphorus (0.2–0.8 %) as the only dietary variable. After 28 days, no effects of the minerals were found on liver cholesterol concentrations and rates of fecal excretion of bile acids.
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  • 72
    ISSN: 1436-6215
    Keywords: Meerschweinchen ; Ascorbinsäure ; Adaption im Stoffwechsel ; Vitamin C ; guinea pigs ; adaptation inascorbic acid metabolism ; blood ; liver ; spleen ; adrenal glands
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Eine Substitution mit 5 mg/100 g Vitamin C im Futter stellt für Meerschweinchen anscheinend die untere Grenze dar, um ein Überleben zu ermöglichen. Sie scheinen keine Möglichkeit zu haben, den Stoffwechsel der Ascorbinsäure an diese niedrige Substitution zu adaptieren. Meerschweinchen, die über lange Zeit (6–8 Wochen) 20 mg/100 g oder 680 mg/100 g Vitamin C im Futter erhalten hatten, zeigen, nachdem der Vitamin-C-Gehalt im Futter drastisch verändert worden ist, bei den Ascorbinsäurespiegeln mehrerer Organe das für eine ablaufende Adaptation typische Überbzw. Unterschwingen.
    Notes: Summary Guinea pigs supplied with 5 mg/100 g vitamin in the food seem to be at the marginal substitution for a survival and show no ability to adapt the ascorbic acid metabolism to this low support. Guinea pigs longlastingly (6–8 weeks) supplied with 20 mg/100g or 680 mg/100g vitamin C in the food show the typical symptoms of an evolving adaptation by an overshooting in the course of the ascorbic acid levels in several organs after a switch to an extremely different vitamin C supply.
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  • 73
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    European journal of nutrition 28 (1989), S. 1-2 
    ISSN: 1436-6215
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
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  • 74
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    European journal of nutrition 28 (1989), S. 17-31 
    ISSN: 1436-6215
    Keywords: Calciumversorgung ; Bioverfügbarkeit von Calcium ; Osteoporose ; osteoporosis ; osteoporosis ; pathogenesis of ; calcium supply ; nutritional aspects of osteoporosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary Osteoporosis primarily affects women and is a bone disease of great socialmedical and economic importance. The pathogenesis is thought to be of multifactorial origin. The current work discusses nutritional aspects relative to osteoporosis. In this aspect, calcium supply seems to have the largest preventional importance. In contrast, food statistics and individual food records show that calcium intake of females is below the DGE's recommendation of 800 mg/daily. Furthermore, in view of skeletal integrity, calcium intake should be increased up to 1,500 mg/daily after menopause, because of endocrinological changes in calcium metabolism. Therefore, calcium intake on the whole is usually found to not be sufficient. The importance of further nutritional aspects for manifestation of osteoporosis are discussed. In some cases, influences on skeletal integrity are quite evident, whereas the literature has only infrequently drawn conclusions about the pathogenesis of osteoporosis.
    Notes: Zusammenfassung Die Osteoporose ist eine Knochenerkrankung mit großer sozialmedizinischer und volkswirtschaftlicher Bedeutung, von der überwiegend Frauen betroffen sind. Die Pathogenese der Erkrankung ist multifaktoriell. Der derzeitige Kenntnisstand über die Bedeutung alimentärer Faktoren wird in diesem Zusammenhang dargestellt. Größte präventive Bedeutung besteht seitens der Ernährung in einer ausreichenden Calciumversorgung. Verzehrsstatistiken und individuelle Verzehrsprotokolle zeigen dagegen, daß die Versorgung mit Calcium beim weiblichen Geschlecht im Durchschnitt unter der Empfehlung der DGE von 800 mg/d liegt. Hinzu kommt, daß zur Aufrechterhaltung der Knochenhomöostase aufgrund endokriner Umstellungen im Calciumstoffwechsel empfohlen wird, nach der Menopause die Calciumaufnahme auf 1500 mg/d zu steigern. Die Versorgungslage mit Calcium ist somit insgesamt als sehr unzureichend anzusehen. Weitere ernährungsbedingte Faktoren mit Bedeutung für eine Osteoporosemanifestation werden diskutiert. In einigen Fällen ist hierdurch eine Beeinflussung der Knochenhomöostase durchaus denkbar, häufig ist das Datenmaterial allerdings noch zu unvollständig oder fehlt völlig, um Zusammenhänge zur Osteoporoseentstehung herstellen zu können.
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  • 75
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    European journal of nutrition 28 (1989), S. 93-102 
    ISSN: 1436-6215
    Keywords: Vitamin A-Status ; polyhalogenierte aromatischeKohlenwasserstoffe ; Metabolismus ; polareRetinoide ; vitamin A status ; polyhalogenated aromatic hydrocarbons ; metabolism ; polar retinoids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Ausreichende Vitamin-A-Speicher und -Gewebslevel werden durch ein Gleichgewicht von Nachfrage der Gewebe nach Vitamin A und der Vitamin-A-Aufnahme durch die Nahrung aufrechterhalten und durch viele Faktoren beeinflußt. Es ist hinreichend bekannt, daß polyhalogenierte aromatische Kohlenwasserstoffe (PHAH) die Vitamin-A-Speicher der Leber erniedrigen. Neuere Untersuchungen deuten darauf hin, daß die Erniedrigung der Vitamin-A-Leberspeicher von einem Anstieg des Vitamin-A-Gehaltes in Serum und Niere sowie von einer erhöhten Abgabe von Vitamin-A-Metaboliten in Urin und Fäzes begleitet sind. Die Untersuchung der Vitamin-A-Verteilung in verschiedenen Geweben zeigte, daß die Zufuhr von PHAH zu einem verstärkten Auftreten polarer Vitamin-A-Metaboliten führt. Es ist wahrscheinlich, daß die PHAH Enzyme beeinflussen, die entscheidend für die Regulation von Vitamin-A-Speichern sowie der Aktivität von für den Vitamin-A-Stoffwechsel wichtigen Enzymen sind.
    Notes: Summary Adequate stores and adequate tissue levels of vitamin A are maintained by a balance of tissue demands and dietary intake of the vitamin and are modified by many factors, including xenobiotics. It is well established that exposure to polyhalogenated aromatic hydrocarbons (PHAH) decreases hepatic content of vitamin A. Recent findings indicate that hepatic depletion of vitamin A is accompanied by an increase in serum and renal vitamin A content and enhanced excretion of vitamin A metabolites in urine and feces. Examination of tissue retinoid profiles reveals that PHAH exposure causes the generation of increased amounts of polar retinoids. It is very likely that PHAH affect enzymes crucial for regulation of vitamin A storage as well as enhance activities of specific enzymes in vitamin A metabolic pathway.
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  • 76
    ISSN: 1436-6215
    Keywords: Stickstoffbilanz ; Proteinbedarf ; Krallenaffen ; Callitrichidae ; nitrogen balance ; protein requirement ; marmoset ; C allitrichidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung An erwachsenen männlichen Weißbüscheläffchen (Callithrix jacchus) erfolgten Stickstoffbilanzmessungen bei Verfütterung von „halbsynthetischen“ und „synthetischen“ Diäten mit Proteingehalten von null bis sieben Prozent. Der tägliche Stickstoffverlust bei längerer proteinfreier Ernährung („Abnutzungsquote“) betrug 131±16 mg/kg Körpergewicht0,75. Eine N-Bilanz =±0 wurde mit der Zufuhr von 261 mg N/kg0,75 in Form hochwertiger Proteine erreicht. Sehr geringe Proteinaufnahme oder das Fehlen von Arginin und Histidin in einer Aminosäurenmischung führte zu Koprophagie. Es wird gefolgert, daß der Proteinbedarf erwachsener Krallenaffen dem des erwachsenen Menschen (auf der Basis des metabolischen Körpergewichts) sehr ähnlich ist. Etwa 6–7% Protein hoher Qualität, auf Trockensubstanz bezogen, genügen zur Vermeidung einer negativen Stickstoffbilanz.
    Notes: Summary Nitrogen balance studies were conducted in adult male marmosets (Callithrix jacchus) using purified and semipurified diets with protein levels between 0% and 7%. Daily nitrogen loss in a state of prolonged protein free nutrition was 131±16 mg/kg body weight0.75. Zero nitrogen balance resulted from mean daily intake of 261 mg nitrogen/kg0.75 when high quality protein sources were used. Very low protein intake or the lack of arginine and histidine in an amino acid mixture induced coprophagy. It is concluded that the protein requirement of adult marmosets is very similar to the protein requirement of adult humans (based on metabolic body weight). About 6–7% high quality protein, based on dry matter, suffice to avoid a negative nitrogen balance in all individuals.
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    European journal of nutrition 28 (1989), S. 211-224 
    ISSN: 1436-6215
    Keywords: Klinische Ernährungstherapie ; Aminosäurenlösungen,Aminogramme ; Key words ; Clinical nutrition ; amino acids, analytical interpretation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary The high value of clinical nutrition as an important component in polypragmatic therapy of severely ill patients with increasing age and restricted compensatory capacity is today unquestioned. The areas of interest and applications have reached a high degree of complexity by many differentiations. The metabolic interrelations under pathological conditions influence especially the application of amino acids. By the enormously increased standards of analytical procedures and instruments huge amounts of data have been gathered but methods and tools for interpreting the complex analytical results have not been developed to the same degree. Considering physiological, pathological biochemical, and biophysical alterations, this review discusses application of amino acids, evaluation and interpretation procedures, as well as indications, contraindications, and effective monitoring. The important regulatory function of the liver in connection with the urea production rate, and the physiological pattern and concentrations of amino acids in plasma are both discussed in detail. Also discussed is the therapeutic advantage of determining total concentration and relative composition of the amino acid pool in plasma, especially in severely ill patients.
    Notes: Zusammenfassung Der hohe Stellenwert der klinischen Ernährungstherapie ist in der heutigen polypragmatischen Therapie schwerstkranker und zum Teil sehr alter Patienten mit eingeschränkter Kompensationsfähigkeit unbestritten. Das Einsatzfeld der klinischen Ernährungstherapie hat dadurch eine starke Differenzierung und einen hohen Komplizitätsgrad erreicht. Diese Wechselbeziehung des pathologischen Ablaufs im Stoffwechsel nach äußeren und inneren Belastungen und den einzelnen Substraten betrifft im hohen Maße die Anwendung von Aminosäuren. Durch die enorme Zunahme der analytischen Leistungsfähigkeit ist das Erkenntnismaterial im Bereich der Aminosäurenversorgung zwar stark angewachsen, aber die Interpretation des komplexen Zusammenhangs der Aminosäuren keineswegs in gleicher Weise verbessert worden. In der vorliegenden Arbeit wird auf dem grobskizzierten Hintergrund physiologischer und pathologischer Stoffwechselzusammenhänge der Einsatz von Aminosäuren dergestalt abgehandelt, daß über eine plausible Interpretation der komplexen analytischen Daten die Indikation, Kontraindikation und überwachung der Aminosäurenapplikation verständlich wird. Vor allem die Bedeutung der Regulation durch die Leber, der Zusammenhang mit der Harnstoffproduktionsrate sowie die differente Bedeutung der mikromolaren und relativen Aminosäurenmuster im Plasma werden so abgehandelt, daß sie für die Interpretation auch schwerkranker Zustände herangezogen werden können.
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  • 78
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    European journal of nutrition 28 (1989), S. 279-299 
    ISSN: 1436-6215
    Keywords: Eisenmangel, Epidemiologie ; Eisenresorption ; Eisensubstitution ; Eisenintoxikation ; iron deficiency ; epidemiology ; iron absorption ; iron substitution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary Iron is an essential trace element. In its heme-form as well as in its non heme-form it is a part of enzymes and hemoproteins. For a safe and adequate dietary intake 10–18 mg of iron are recommended daily. Frequently, this quantity is not available: approximately 20 % of the world population is iron-deficient. In this state the enteral transfer capacity for toxic metals, e.g., Cd and Pb, is increased and the adaptation to physical strain as well as the immunological responses are depressed. Alterations of body iron-stores are almost exclusively balanced by adequate adaptation of the enteral iron-transfer capacity. The mechanism of this adaptation process can neither be satisfactorily explained by the “mucosal block hypothesis”, nor by the “mucosal transferrin hypothesis”. When the time-course of iron storage and its relation to intestinal iron transfer was investigated after i.v. iron administration to iron-deficient rats, the results indicated that the process of adaptation is located in the intestinal mucosa. Intestinal iron loading is decreased in iron deficiency, whereas the iron transfer into the organism is increased. Further investigation is necessary to find out by which mechanism the iron manages to bypass existing mucosal storage capacity in this situation. The geographical distribution of iron deficiency is influenced by a variety of local factors. Still, the paramount causes of iron-deficiency are unbalanced iron losses and the lack of bioavailable iron in the diet. The bioavailability of non heme iron is influenced by the composition of the diet. The effect of promotors of iron absorption, such as meat, amino acids, polycarbonic acids and ascorbate is opposed by the influence of inhibitors, such as bran, soyaproducts, vegetables and egg-dishes. Iron losses are mainly due to blood losses. Thus, the wide distribution of hockworm diseases in tropical areas contributes significantly to the endemic iron-deficiency in these regions. A more physiological loss of iron is caused by menstruation and pregnancy. In small infants the iron-demand of the organism is increased by rapid growth, which in turn increases the intestinal iron transfer. An increased iron-demand can be balanced by an iron-supplemented diet or by pharmaceutical iron compounds. Acute intoxications can be caused by an overdose of such preparations. The pathophysiology and symptoms of acute iron intoxication are summarized. Their frequency has markedly decreased since “childproof” packaging has been introduced for iron-preparations. To meet the increased iron demand of young children, commercial infant formulas are frequently fortified with iron, preferentially with heme-iron. Inlight of the wide distribution of iron-deficiency a general iron fortification of staple food items is discussed controversially.
    Notes: Zusammenfassung Eisen zählt zu den essentiellen Spurenelementen. Es ist in seiner Häm- und Non-Häm-Form Bestandteil von Hämproteinen und Enzymen. Für eine ausreichende und sichere Versorgung des Organismus werden 10 mg bis 18 mg Eisen in der täglichen Diät empfohlen. Diese Menge wird erheblich häufiger unterals überschritten: Ca. 20 % der Weltbevölkerung haben einen Eisenmangel, der sich u.a. in einer gesteigerten enteralen Resorptionsfähigkeit für Cd und Pb äußert sowie in einer Einschränkung der physischen Leistungsfähigkeit und der Infektabwehr. Veränderungen im Körpereisenstatus werden fast ausschließlich durch Anpassung der enteralen Eisenresorption bedarfsgerecht ausgeglichen. Der Mechanismus dieser Anpassung kann weder durch „Mucosa-Block-Hypothese“ noch durch die „Mucosal-Transferrin“-Hypothese befriedigend erklärt werden. Kinetische Untersuchungen an eisenarmen Ratten über die Speicherung parenteral gegebenen Eisens und die Auswirkungen dieser Gabe auf die Eisenresorption deuten jedoch auf einen lokalen Adaptationsprozeß in der intestinalen Mukosa. Dabei ist die Beladung der Mukosa mit angebotenem Eisen im Eisenmangel herabgesetzt, der Transfer dagegen erhöht. Wie das Eisen in diesem Zustand an den vorhandenen Speicherkapazitäten der Mukosa vorbeigeleitet wird, bedarf weiterer Klärung. Die geographische Verteilung des Eisenmangels unterliegt einer Reihe lokaler Einflüsse. Hauptursachen des Eisenmangels sind der Mangel an bioverfügbarem Eisen in der Nahrung und unausgeglichene Eisenverluste. Die Bioverfügbarkeit von Non-Häm-Eisen in der Nahrung wird durch die Zusammensetzung der Diät beeinflußt. Resorptionsfördernde Komponenten wie Fleisch, Aminosäuren, Polycarbonsäuren und Ascorbat saldieren sich in der Wirkung mit Hemmstoffen der Eisenresorption wie z.B. Kleie und Sojaprodukte, Gemüse und Eispeisen. Eisenverluste sind in erster Linie Blutverluste, wobei der in den Tropen verbreitete Befall mit Hakenwürmern starken Anteil an dem dort endemischen Eisenmangel hat. Andere, eher physiologische Eisenverluste entstehen durch Menstruation und Schwangerschaft. Während des raschen Wachstums im Säuglingsalter entsteht ebenfalls ein stark erhöhter Eisenbedarf, der zu gesteigertem Eisentransfer führt. Erhöhter Eisenbedarf kann durch medikamentöse Eisensubstitution oder durch adäquate Ernährung gedeckt werden. Eisenmedikamente können jedoch bei nicht bestimmungsgemäßem Gebrauch zu akuten Intoxikationen führen, deren Bild detailliert beschrieben wird. Die Inzidenz solcher Vergiftungen ist seit Einführung „kindersicherer“ Verpackungen für Eisenpräparate stark zurückgegangen. Zur Deckung des durch Wachstum erhöhten Eisenbedarfs wird kommerzielle Säuglingsbeikost häufig mit Eisen fortifiziert, wobei Häm-Eisen die größeren Vorzüge bietet. Eine allgemeine Fortifikation von Grundnahrungsmitteln mit Eisen ist jedoch trotz der weiten Verbreitung des Eisenmangels stark umstritten.
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  • 79
    ISSN: 1436-6215
    Keywords: guinea pigs ; adaptation ofhepatic microsomal proteins andcytochromes P-450 and b5 to differentvitamin C supplies ; Meerschweinchen, mikrosomales Protein ; Cytochrome P-450 und b5 ; Vitamin-C-Substitution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Meerschweinchen, die über lange Zeit (6–8 Wochen) 680 mg/ 100 g Vitamin C im Futter erhalten hatten und dann 10 Wochen lang substituiert wurden mit 5 mg/100 g, konnten in der Leber nicht die Gehalte an mikrosomalem Cytochrom P-450 aufrechterhalten 20 mg/100 g, zeigten in der Leber das für eine Adaptation typische Unterschwingen bei dem Gehalt an mikrosomalem Cytochrom P-450.
    Notes: Summary Guinea pigs longlastingly (6–8 weeks) supplied with 680 mg/100 g vitamin in the food and for ten weeks thereafter exposed to: 5 mg/100 g: show no ability to maintain the amounts of hepatic microsomal cytochrome P-450 20 mg/100 g: show the typical symptom of an evolving adaptation by an overshoot of the amounts of hepatic microsomal cytochrome P-450.
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  • 80
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    European journal of nutrition 17 (1978), S. 52-57 
    ISSN: 1436-6215
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary A new enzymatic method for simultaneous estimation of radioactivity of 1-14C-glucose and 1-14C-fructose is described. It is based on the isomerisation of 1-14C-fructose to 1-14C-glucose by phosphoglucoseisomerase (EC 5.3.1.9) and on its enzymatic removal as ribulose-5-phosphate and14CO2. The method is specific, reproducible, and gives over 97 % recoveries of glucose and fructose concentrations up to 11 mmol/l in aquos and biological solutions.
    Notes: Zusammenfassung Beschrieben wird eine neue enzymatische Methode zur gleichzeitigen Radioaktivitätsbestimmung von 1-14C-Glukose und 1-14C-Fruktose. Prinzip ist die Umwandlung von 1-14C-Fruktose in 1-14C-Glukose mit Phosphoglukoseisomerase (EC 5.3.1.9) und anschließende Umwandlung der gebildeten 1-14C-Glukose in Ribulose-5-phosphat und14CO2. Das Verfahren ist spezifisch, gut reproduzierbar und ergibt Wiederfindungsraten in wäßrigen und biologischen Flüssigkeiten von 97 % bis zu Glukose- und Fruktose-Konzentrationen von 11 mmol/l.
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  • 81
    ISSN: 1436-6215
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Notes: Summary In maturity onset diabetes the blood levels of total blood keto acids in terms of pyruvic, serum citric, calcium are significantly higher than in normal adults, while there is a decrease in reduced-blood glutathione, serum zinc, potassium and sodium levels. There were no significant differences between diabetes and normal adults in the serum levels of copper, ceruloplasmin oxidase activity, iron and magnesium.
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    Journal of plant growth regulation 8 (1989), S. 167-174 
    ISSN: 1435-8107
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Paclobutrazol, triapenthenol (RSW0411), and BAS111 were applied to 4-week-old Delicious apple seedlings (Malus domestica Borkh.) as a root drench at 0.1, 1.0, and 10.0 mg per plant. Paclobutrazol eliminated shoot extension growth for 8 weeks at all three rates. RSW0411 controlled shoot elongation only at the highest rate. BAS111 produced the widest response, with shoot growth ranging from 38% to 93% of controls for the highest and lowest rates, respectively. Generally, leaf area decreased and leaf density increased with increasing rates of all chemicals. Root weight of plants treated with paclobutrazol nearly doubled but increased only slightly with RSW0411 and BAS111. Chemical analysis of the leaf tissue 8 weeks after treatment showed paclobutrazol levels highest, followed by RSW0411 and BAS111.
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    Journal of plant growth regulation 8 (1989), S. 199-204 
    ISSN: 1435-8107
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The growth retardants paclobutrazol (β-[(4-chlorophenyl)methyl]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol) and RSW 0411 (β-(cyclohexyl methylene)-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol) were tested on two-year-old trees of Granny Smith and Fuji apple. RSW 0411 at 100 mg/L did not cause any growth reduction in Granny Smith, while 500 and 1000 mg/L significantly reduced growth below that of the control between 27 and 40 days after application. Paclobutrazol at 100 mg/L had significantly reduced shoot growth between 27 and 55 days after application, and 1000 mg/L reduced shoot growth between 27 and 82 days after application. By 100 days after application, there were no longer differences between treatments. Shoot growth on Fuji trees was reduced below that of the control as follows: between 14 and 27 days following a single application of 500 mg/L RSW 0411; between 27 and 55 days following two applications; between 14 and 72 days following three applications; and between 14 and 82 days following four applications. Treatments were applied 14 days apart. Paclobutrazol was a more active growth retardant than RSW 0411 at the same rate, and the growth-retarding effects of RSW 0411 were short-lived.
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    Journal of plant growth regulation 8 (1989), S. 211-223 
    ISSN: 1435-8107
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A series of 9-substituted derivatives of four common naturally occurring cytokinins was tested for growth response in the soybean callus assay. The 9-substituents, 2-carboxyethyl (-C2CO2H), 2-carbo-t-butoxyethyl (-C2CO2 tBu), and 2-nitriloethyl (-C2CN), all reduced the biological activity of the parent compound. The order of activities was, in general,-C2CO2H 〉 -C2CO2 tBu 〉 -C2CN and followed the unsubstituted cytokinin response pattern of E-zeatin (E-Z) 〉 Z-zeatin (Z-Z) 〉 ≅ (R,S)-dihydrozeatin [(diH)Z] 〉N-(3-methyl-2-butenyl)-1H-purin-6-amine (iP). The nature of the dose-response curves indicate that the activities of the derivatives are a function of their affinities to a common receptor site and that their steric and polar properties determine that affinity. The 9-(2-carboxyethyl) cytokinins provide a practical alternate source of haptens for the raising of cytokinin antibodies, since sugar-cleavage oxidations are avoided in the preparation of the antigens. E-9-(2-carboxyethyl)-O-β-D-glucopyranosylzeatin (E-ZOG9C2CO2H) was synthesized for the purpose of making antibodies specific for E-O-β-D-glucopyranosylzeatin (E-ZOG) and was also assayed for its growth response. The results obtained with stable 9-substituted cytokinins are useful in defining guidelines for the design of ligands available to explore receptor-site topology.
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    Journal of plant growth regulation 8 (1989), S. 225-236 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Aging carnation flower parts were used to determine whether or not any correlation existed between the concentration of abscisic acid (ABA) and a predisposition of the tissue for ethylene synthesis. Levels of ABA were measured using an enzyme-linked immunosorbent assay (ELISA) following purification steps including prepacked silica gel columns. Increased ABA levels paralleled the increase of ethylene and the onset of irreversible wilting in the carnation petals. Neither the green tissue nor the receptacle showed any sign of wilting with the remainder of the flower parts, but increased ABA was detected in both tissues subsequent to, or coincident with, the ethylene climacteric peak in the senescing petals. An increase of ABA in both the styles and the ovary was detected in the preclimacteric flower, and did not appear to be triggered by the production of ethylene. Increased ABA in the gynoecium also did not result in the onset of ethylene production in the preclimacteric flower.
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    Journal of plant growth regulation 8 (1989), S. 249-253 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Seasonal levels of indole-3-acetic acid (IAA) present in buds, meristematic tissues, and leaves of 1-year-old shoots of two selections (vigorous and dwarf) of a F2 generation apple population with original “Goldspur” × “Redspur” parentage were determined using gas chromatography—selected ion monitoring—mass spectrometry (GC-SIM-MS) with a13C-IAA internal standard. A comparison of IAA levels through one growing season was made in the shoots of two trees differing in growth. The levels of IAA in the leaves of the vigorous tree were higher in the early and late growing seasons, as compared to those in the dwarf tree. Levels of IAA in buds of the dwarf tree shoots were found to be higher than in those of the vigorous tree shoots.
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    Journal of plant growth regulation 8 (1989), S. 273-282 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Nine gibberellins (GAs) have been identified from tissues of Valencia orange (Citrus sinensis Osbeck) using gas chromatography—mass spectrometry and gas chromatography-selected ion monitoring of high-performance liquid chromatography (HPLC)-fractionated extracts. These GAs are GA1, GA3, GA8, GA19, GA20, GA29, 3-epi-GA1, 2-epi-GA29, and iso-GA3. Selected-ion monitoring and stable-isotope dilution assays have been used to estimate levels of some of these GAs in vegetative and reproductive tissues. GA29 was found to be the most abundant GA measured. GA1 was found in all samples examined, and there was always less 3-epi-GA1 than GA1. GA20 was present in most extracts. Leaves of developing inflorescence shoots contained six times more GA29 than did leaves of comparable vegetative shoots. Levels of GA29 increased during the early stages of fruit development. GA20 may be more abundant in growing fruitlets than in those about to abscise; however, there were no consistent differences in the relative amounts of the other GAs. No major differences were found between tissues of immature seeded and seedless fruit, and developing seeds did not contain high levels of any of the GAs measured. It is concluded that seed-produced GAs are not essential for normal fruit development in Valencia orange.
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    Journal of plant growth regulation 8 (1989), S. 301-307 
    ISSN: 1435-8107
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Thidiazuron [(TDZ)N-phenyl-N′-1,2,3-thidiazol-5-ylurea] at 750 μM was applied to buds of apple trees to determine if it could substitute for the chilling requirement to induce bud break. Shoots of cv. ‘Anna’ (low chill), ‘Delicious’ cv. Redchief (medium chill), and ‘Northern Spy’ (high chill) were untreated, treated with TDZ prior to chilling (before-chill), and treated with TDZ at various intervals after the accumulation of specific amounts of chilling (after-chill). Shoots were stored in a cold room at 4°C. TDZ applied prior to chilling reduced the chill unit (CU) requirement (1 CU = 1 h at 4°C) for the promotion of bud break on 1-year-old shoots of ‘Anna’ and ‘Northern Spy’ and 1- and 2-year-old wood of ‘Delicious.’ TDZ applied after-chill promoted bud break only for ‘Anna’ and buds on 2-year-old wood of ‘Delicious.’ While accumulating CUs, untreated buds or buds treated with TDZ on 1-year ‘Delicious’ and ‘Northern Spy’ did not respond to the cold treatment even after 1848 h of CU accumulation. For all three cultivars, TDZ treatment was more effective in promoting bud break when applied before the initiation of chilling.
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    Journal of plant growth regulation 8 (1989), S. 283-291 
    ISSN: 1435-8107
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Three auxin-inducible genes of the soybean SAUR (small auxin up RNAs) locus, along with two flanking genes, have been transferred into petunia usingAgrobacterium tumefaciens T-DNA transformation. Genomic analysis showed that two transgenic petunia plants contained one copy of the SAUR locus, and one plant contained approximately 10 copies of the transferred locus. Gene-specific probes were used to probe RNA blots, and our results indicated that the three genes were transcriptionally induced by the addition of the auxin, 2,4-dichlorophenoxyacetic acid (2,4-D) to excised young leaves of the transgenic plants. This suggests that elements involved in auxin-regulated gene expression are strongly conserved in soybean and petunia. The two plants containing one copy of the SAUR locus showed nearly equal expression of all three SAUR genes after 2,4-D induction, while the plant with 10 copies showed a dramatic under-expression of two of the three genes following auxin administration. RNase protection analysis of the transcript for SAUR locus gene 6B showed that the transcription start site for this gene in the three transformed petunia plants was identical to that in soybean.
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    Journal of plant growth regulation 8 (1989), S. 319-325 
    ISSN: 1435-8107
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Yellowing is a visible result of ethylene-enhanced senescence. In certain plants, such asCucumis sativus, an increase in peroxidase levels occurs during this period. Experiments described here were designed to test the hypothesis that peroxidase levels induced during senescence play a role in chloroplast degradation. Inhibitors of heme synthesis and protein glycosylation, which had no effect on chlorophyll degradation, reduced the synthesis of pI 9 peroxidase. Decapitation of seedlings, which enhanced greening of cotyledons, increased levels of peroxidase. These observations are consistent with the view that while the role of aging- or ethylene-induced peroxidases are not known, they are not involved in chlorophyll degradation.
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  • 91
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    Stochastic environmental research and risk assessment 3 (1989), S. 85-96 
    ISSN: 1436-3259
    Keywords: Stochastic equations ; irregularly spaced observations ; prediction, interpolation ; random fields
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract The steady state two dimensional groundwater flow equation with constant transmissivities was studied by Whittle in 1954 as a stochastic Laplace equation. He showed that the correlation function consisted of a modified Bessel function of the second kind, order 1, multiplied by its argument. This paper uses this pioneering work of Whittle to fit an aquifer head field to unequally spaced observations by maximum likelihood. Observational error is also included in the model. Both the isotropic and anisotropic cases are considered. The fitted field is then calculated on a two dimensional grid together with its standard deviation. The method is closely related to the use of two-dimensional splines for fitting surfaces to irregularly spaced observations.
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  • 92
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    Stochastic environmental research and risk assessment 3 (1989), S. 71-84 
    ISSN: 1436-3259
    Keywords: Hydraulics ; quasilinearization ; simulation ; stochastic ; estuarine system ; Monte Carlo methods ; random differential equations ; parameter uncertainty
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract A new methodology is presented for the solution of the stochastic hydraulic equations characterizing steady, one-dimensional estuarine flow. The methodology is predicated on quasi-linearization, perturbation methods, and the finite difference approximation of the stochastic differential operators. Assuming Manning's roughness coefficient is the principal source of uncertainty in the model, stochastic equations are presented for the water depths and flow rates in the estuarine system. Moment equations are developed for the mean and variance of the water depths. The moment equations are compared with the results of Monte Carlo simulation experiments. The results confirm that for any spatial location in the estuary that (1) as the uncertainty in the channel roughness increases, the uncertainty in mean depth increases, and (2) the predicted mean depth will decrease with increasing uncertainty in Manning'sn. The quasi-analytical approach requires significantly less computer time than Monte Carlo simulations and provides explicit
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    Stochastic environmental research and risk assessment 3 (1989), S. 135-153 
    ISSN: 1436-3259
    Keywords: Stochastic partial differential equations ; maximum likelihood estimation ; parameter estimation ; moment equations ; stodhastic contaminant transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract Many problems in hydraulics and hydrology are described by linear, time dependent partial differential equations, linearity being, of course, an assumption based on necessity. Solutions to such equations have been obtained in the past based purely on deterministic consideration. The derivation of such a solution requires that the initial conditions, the boundary conditions, and the parameters contained within the equations be stipulated in exact terms. It is obvious that the solution so derived is a function of these specified, values. There are at least four ways in which randomness enters the problem. i) the random initial value problem; ii) the random boundary value problem; iii) the random forcing problem when the non-homogeneous part becomes random and iv) the random parameter problem. Such randomness is inherent in the environment surrounding the system, the environment being endowed with a large number of degrees of freedom. This paper considers the problem of groundwater flow in a phreatic aquifer fed by rainfall. The goveming equations are linear second order partial differential equations. Explicit form solutions to this randomly forced equation have been derived in well defined regular boundaries. The paper also provides a derivation of low order moment equations. It contains a discussion on the parameter estimation problem for stochastic partial differential equations.
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    Stochastic environmental research and risk assessment 3 (1989), S. 179-190 
    ISSN: 1436-3259
    Keywords: Groundwater ; Stochastic ; Monte Carlo simulation ; First order Taylor series approximation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract The expected head and standard deviation of the head from the first order Taylor series approximation is compared to Monte Carlo simulation, for steady flow in a confined aquifer with transmissivity as a random variable. Emphasis is on the effect of changes in the covariance structure of the transmissivity, and pumping rates, on the errors in the first order Taylor series approximation. The accuracy of the first order Taylor series approximation is found to be particularly sensitive to pumping rates. With significant pumping the approximation is found to under estimate both the expected drawdown and head variance, and the error increases as the pumping rate increases. This can lead to large errors in probability constraints based on moments from the first order Taylor series approximation.
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    Stochastic environmental research and risk assessment 3 (1989), S. 227-240 
    ISSN: 1436-3259
    Keywords: Kalman filter ; Maximum likelihood estimation ; Periodic models ; Stochastic hydrology ; Time series analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract An exact maximum likelihood procedure is presented for estimating the parameters of a periodic autogressive-moving average (PARMA) model. To develop an estimator which is both statistically and computationally efficient, the PARMA class of models is written using a state-space representation and a Kalman filtering algorithm is used to estimate the parameters. In order to demonstrate how to fit PARMA models in practice, the most appropriate types of PARMA models are identified for fitting to two average monthly riverflow time series and the new estimator is employed for estimating the model parameters.
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    Stochastic environmental research and risk assessment 3 (1989), S. 17-29 
    ISSN: 1436-3259
    Keywords: Stochastic optimization ; linear programming ; simplex method ; Karmarkar's method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract Optimization of multi-reservoir systems operations is typically a very large scale optimization problem. The following are the three types of optimization problems solved using linear programming (LP): (i) deterministic optimization for multiple periods involving fine stage intervals, for example, from an hour to a week (ii) implicit stochastic optimization using multiple years of inflow data, and (iii) explicit stochastic optimization using probability distributions of inflow data. Until recently, the revised simplex method has been the most efficient solution method available for solving large scale LP problems. In this paper, we show that an implementation of the Karmarkar's interior-point LP algorithm with a newly developed stopping criterion solves optimization problems of large multi-reservoir operations more efficiently than the simplex method. For example, using a Micro VAX II minicomputer, a 40 year, monthly stage, two-reservoir system optimization problem is solved 7.8 times faster than the advanced simplex code in MINOS 5.0. The advantage of this method is expected to be greater as the size of the problem grows from two reservoirs to multiples of reservoirs. This paper presents the details of the implementation and testing and in addition, some other features of the Karmarkar's algorithm which makes it a valuable optimization tool are illuminated.
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    Stochastic environmental research and risk assessment 3 (1989), S. 51-67 
    ISSN: 1436-3259
    Keywords: Spatial rainfall estimation ; kriging ; ordinary co-kriging ; disjunctive co-kriging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract The feasibility of linear and nonlinear geostatistical estimation techniques for optimal merging of rainfall data from raingage and radar observations is investigated in this study by use of controlled numerical experiments. Synthetic radar and raingage data are generated with their hypothetical error structures that explicitly account for sampling characteristics of the two sensors. Numerically simulated rainfall fields considered to be ground-truth fields on 4×4 km grids are used in the generation of radar and raingage observations. Ground-truth rainfall fields consist of generated rainfall fields with various climatic characteristics that preserve the space-time covariance function of rainfall events in extratropical cyclonic storms. Optimal mean areal precipitation estimates are obtained based on the minimum variance, unbiased property of kriging techniques under the second order homogeneity assumption of rainfall fields. The evaluation of estimated rainfall fields is done based on the refinement of spatial predictability over what would be provided from each sensor individually. Attention is mainly given to removal of measurement error and bias that are synthetically introduced to radar measurements. The influence of raingage network density on estimated rainfall fields is also examined.
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    Stochastic environmental research and risk assessment 3 (1989), S. 97-110 
    ISSN: 1436-3259
    Keywords: ARMA processes ; fractionally differencedARMA processes ; long memory ; spectral density ; maximum likelihood estimates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract A class of regression type estimators of the parameterd in a fractionally differencedARMA (p, q) process is introduced. This class is an extension of the estimator considered by Geweke and Porter-Hudak. In a simulation study, we compared three estimators from this class together with two approximate maximum likelihood estimators which are based on two separate approximations to the likelihood. One approximation ignores the determinant term in the likelihood and the other includes a compensating factor for the determinant. When the determinant term is included, the estimate tends to be much less biased and is in general superior to the other estimate. The approximate maximum likelihood estimator out performed, by a large margin, the regression type estimators for pureARIMA (0,d,0) processes. However, forARIMA (1,d,1) processes, a regression type estimator turned out to be the best for realizations of length 400 in 3 out of the 5 cases we tried.
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    Stochastic environmental research and risk assessment 3 (1989), S. 111-133 
    ISSN: 1436-3259
    Keywords: Rainfall-runoff models ; random channel network ; regionalization ; flood frequency ; instanteous unit hydrograph
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract A rainfall-runoff model is used in conjunction with a probabilistic description of the input to this model to obtain simple regression-like relations for basin runoff in terms of basin and storm characteristics. These relations, similar to those sought in regionalization studies, are computed by evaluating the conditional distribution of model output given basin and storm characteristics. This method of conditioning provides a general way of examining model sensitivity to various components of model input. The resulting relations may be expected to resemble corresponding relations obtained by regionalization using actual runoff to the extent that the rainfall-runoff model and the model input specification are physically realistic. The probabilistic description of model input is an extension of so-called “random-model” of channel networks and involves postulating an ensemble of basins and associated probability distributions that mimic the variability of basin characteristics seen in nature. Application is made to small basins in the State of Wyoming. Parameters of the input variable distribution are estimated using data from Wyoming, and basin-scale relations are estimated both, parametrically and nonparametrically using model-generated runoff from simulated basins. Resulting basin-scale relations involving annual flood quantiles are in reasonable agreement with those presented in a previous regionalization study, but error estimates are smaller than those in the previous study, an artifact of the simplicity of the rainfall-runoff model used in this paper. We also obtain relations for peak of the instantaneous unit hydrograph which agree fairly well with theoretical relations given in the literature. Finally, we explore the issues of sensitivity of basin-scale, relations and error estimates to parameterization of the model input probability distribution and of how this sensitivity is related to making inferences about a particular ungaged basin.
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    Stochastic environmental research and risk assessment 3 (1989), S. 191-202 
    ISSN: 1436-3259
    Keywords: Random variable ; Distribution ; Estimation ; Probability analysis ; Cross-entropy ; Fractile constraints ; Flood
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract The cross-entropy method with fractile constraints has been developed to estimate a random variable when the data are a set of independent observations of the variable. The method can claim several advantages over existing methods. It uses a reference distribution like the prior distribution in Bayesian analysis and likewise generates a posterior distribution. The method is of interest, in particular, because it satisfies two fundamental requirements for selfconsistency in the analysis of a probabilistic system based on data: a principle of invariance and a principle of data monotonicity. The method is applied to flood analysis. Robustness of the minimum cross-entropy method is compared with other methods: the methods of moments and the maximum likehood.
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