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  • Articles  (20,937)
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  • 2010-2014
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  • 1
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    Circuits, systems and signal processing 7 (1988), S. 3-19 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract In this paper we present results in the development of decimation-in-frequency algorithms for a family of discrete sine and cosine transforms. They are closely related to the decimation-in-time algorithms developed by Yip and Rao [1]. The complexity of the algorithms was examined through the number of multiplications and additions as well as the number of different constants required in the transforms. It was found that the decimation-in-frequency approach provides a viable alternative to other fast algorithms for the discrete sine and cosine transforms. In particular, the recursive and modular structure of the algorithms lends itself readily to possible hardware realization.
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  • 2
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    Circuits, systems and signal processing 7 (1988), S. 113-113 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
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  • 3
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    Circuits, systems and signal processing 7 (1988), S. 115-118 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
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  • 4
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    Circuits, systems and signal processing 7 (1988), S. 173-189 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract A fixed-size systolic array which can efficiently triangularize arbitrarily large matrices is presented. The array performs orthogonal triangularization by applying Givens' rotations in parallel. For matrices larger than the array, the triangularization is accomplished by emulating a large array with the fixed-size array. The distinguishing features of this array are (1) only one type of cell is used, (2) only unidirectional data flow is required, and (3) the array is rectangular shaped. These properties make it more suitable to emulate arbitrarily large arrays by feedback emulation. The array can also efficiently compute the eigenvalues of arbitrarily large matrices by theQR algorithm, because it can also perform theQR decomposition. In the computation the rotation parameters generated during each stage of theQR decomposition are used in the multiplication before the next stage of decomposition.
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  • 5
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    Circuits, systems and signal processing 7 (1988), S. 213-234 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract On-line signal processing and automatic control applications give rise to numerous examples of computationally intense algorithms. Architectures which are algorithmically specialized and provide massive parallelism are necessary to cope with such computational requirements. Systolic arrays, which feature parallelism, local communications, and VLSI compatability appear to match up well with these computational requirements. This paper summarizes recent research on a general class of nonplanar systolic arrays. These arrays feature closed-loop data flow. The arrays may be switched dynamically to facilitate I/O simplicity and to accommodate iterative calculations without intermediate I/O interdiction. The closed-loop data flows also facilitate restructuring of the array to accommodate specific algorithmic requirements. The potential for multiuser, multialgorithm operation is also enhanced. Matrix operations are used as examples in the development. Algorithms as diversified as the Riccati equation, LU factorization, the Faddeev algorithm, FFT calculation, and controllability Grammians can be implemented on the nonplanar architectures.
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  • 6
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    Circuits, systems and signal processing 7 (1988), S. 275-287 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract In this paper two new systolic structures forLU decomposition of an invertible matrix, having 100% and 50% hardware efficiency, are proposed. In comparison, a previously proposed structure forLU decomposition [1] has a hardware efficiency of only 33%. Utilizing one of the proposed systolic structure forLU decomposition, an integrated systolic structure for solving a system of linear equations is also derived. This is unlike other reported systolic structures for solving a system of linear equations, which are obtained by interconnecting heterogeneous subsystems, requiring complicated data realignment. These improvements in the proposed designs have been brought about by giving due consideration to the input/output data flow pattern between various subcomputations.
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  • 7
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    Circuits, systems and signal processing 7 (1988), S. 345-359 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract Changing the coefficient set of a recursive digital filter during operation results in a transient signal at the filter output. The amplitude of this transient signal may exceed the amplitude of the output signal before and well after the change of coefficients. This effect is rather disturbing in some applications, such as the processing of audio signals. It is shown how these transients can be minimized without increasing the computational complexity of the filter by the use of a properly chosen set of intermediate coefficients.
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  • 8
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    Circuits, systems and signal processing 7 (1988), S. 409-411 
    ISSN: 1531-5878
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    Topics: Electrical Engineering, Measurement and Control Technology
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  • 9
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    Circuits, systems and signal processing 7 (1988), S. I 
    ISSN: 1531-5878
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    Topics: Electrical Engineering, Measurement and Control Technology
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  • 10
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    Circuits, systems and signal processing 7 (1988), S. 467-479 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract A modeling approach is used in the detection of a random signal in colored noise. The received sequence is modeled as a regressive/autoregressive time series, and the presence or absence of the desired signal is determined through a hypothesis testing procedure. The test is based on the construction of anF-statistic using likelihood functions. The statistic can be easily incorporated into the computation of the probability of a false alarm, such as required in the processing of radar signals. Results based on simulated data and actual radar data are presented.
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  • 11
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    Circuits, systems and signal processing 7 (1988), S. 413-424 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract Recent results for nonconservative dynamical systems involve a variational principle of the Hamilton type. In this approach the velocity of variation and the variation of velocity are not commutative as in the case of mechanics governing conservative dynamical systems. In this paper we adapt the above approach to power systems which include the effects of transfer conductances. For such power systems we show that if certain noncommutative rules (which are consistent with the ones used for the variation of velocities in nonconservative dynamical systems) are used, then it is possible to employ a variational principle of the Hamilton type to derive the classical model for power systems. Numerous simulations of specific postfault multimachine power systems have verified that the above noncommutative rules are indeed satisfied for the types of power systems which we consider. The present results give additional understanding for the types of energy functions that have recently been used in transient stability studies of power systems. In these works, several attributes of energy functions have been ascertained by means of simulations and heuristic reasoning, rather than analysis (e.g., path-dependent terms of energy functions have been approximated by making linear trajectory assumptions).
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  • 12
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    Circuits, systems and signal processing 7 (1988), S. I 
    ISSN: 1531-5878
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    Topics: Electrical Engineering, Measurement and Control Technology
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  • 13
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    Circuits, systems and signal processing 7 (1988), S. 511-511 
    ISSN: 1531-5878
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    Topics: Electrical Engineering, Measurement and Control Technology
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  • 14
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    Circuits, systems and signal processing 7 (1988), S. 21-55 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract This paper depicts the connection between algorithms for the factorization of covariance matrices, a basic operation in linear estimation, and whitening or modeling filters. General algorithms for arbitrary covariances are presented and related to the four fundamental types of cascade filters: feed-forward and feed-back tapped delay line or ladder filter. Systolic implementations of the algorithms and realizations of the associated filters illustrate the correspondence between algorithms and filters. Finally, fast algorithms for special covariances are introduced through two important examples: constant-parameter tapped delay line and ladder filter.
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  • 15
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    Circuits, systems and signal processing 7 (1988), S. 57-78 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract This paper introduces a new nonlinear filter that is used for adaptive noise canceling. The derivation and convergence properties of the filter are presented. The performance, as measured by the root mean square error between the signal and its estimate, is compared with that of the commonly used least mean square (LMS) algorithm. It is shown, through simulation, that the proposed nonlinear noise canceler has, on the average, better performance than the LMS canceler. The proposed adaptive noise canceler is based on the Pontryagin minimum principle and the method of invariant imbedding. The computational time for the proposed method is about 10% of that of the LMS, in the studied cases, which is a substantial improvement.
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  • 16
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    Circuits, systems and signal processing 7 (1988), S. 79-94 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract VLSI systolic and wavefront array processors' architectures for the block implementation of infinite impulse response digital filters with very high sample rates are presented. The proposed systolic array processor achieves the maximum possible throughput rate and requires only local data transfers. The asynchronous wavefront array processor operates at the same maximum throughput rate and, moreover, it is characterized by a substantial reduced latency. The throughput rate of the proposed array processor structures is a linear function of the block lengthL and theoretically it may be arbitrary high; however, it is limited only by a number of practical implications.
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  • 17
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    Circuits, systems and signal processing 7 (1988), S. I 
    ISSN: 1531-5878
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    Topics: Electrical Engineering, Measurement and Control Technology
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  • 18
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    Circuits, systems and signal processing 7 (1988), S. 95-109 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The main problems that are the major concern in network testing are fault detection, fault location, and fault prediction. In this paper a multiple-fault-prediction algorithm is proposed for analog circuits with inaccessible nodes. The components in the circuits may be nominals or may be deviated from the nominals within a prescribed tolerance. In the proposed prediction algorithm, the component values are evaluated according to the consecutive voltage measurements that are continuously monitored at the accessible test points at each periodic maintenance. The component values are used to locate the faulty components and/or to predict the components that are about to fail.
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  • 19
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    Circuits, systems and signal processing 7 (1988), S. 119-149 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract In this paper we investigate systolic processing for problems formulated in dynamic programming. These problems are classified as monadic-serial, polyadic-serial, monadic-nonserial, and polyadic-nonserial. Problems in serial formulations can be implemented easily in systolic arrays; however, nonserial problems may have to be transformed into a serial one before an efficient implementation can be found. monadic-serial dynamic programming problem can be solved as the search of an optimal path in a multistage graph and can be computed as a string of matrix multiplications. Three efficient systolic-array designs are presented. A polyadic-serial dynamic programming problem can be solved by either a divide- and-conquer algorithm or the search of optimal solutions in a serial AND/OR-graph. We have evaluated the asymptotically optimal architecture for divide- and-conquer algorithms and have developed efficient methods of mapping a regular AND/OR-graph into systolic arrays. Cases are studied for transforming a problem in a nonserial formulation into a serial one.
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  • 20
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    Circuits, systems and signal processing 7 (1988), S. 151-172 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract A prototype filter design is reviewed to underscore the computational problems arising in such designs. A purely systolic-array architecture is presented. This array provides the computational support necessary for filter design. Due to a simple and novel data steering technique the array is capable of carrying out a number of important matrix operations such as factorization, inversion of factors, and matrix-matrix multiplication. Another interesting attribute is the array's ability to maximally overlap computations of multiphase algorithms. In this study we demonstrate the execution of a dense matrix factorization phase and a factor inversion phase on the array with no need for intraphase or interphase I/O. We show that these phases (which are the backbone of an optimal filtering algorithm) are completed in the optimal count of aboutn time units. The array employs 2n n−n simple processing elements (PEs) that are active every other time unit. It is shown that the functions of two adjacent PEs can be merged and assigned to a single PE thus maximizing PE utilization. A possible design of a “merged” PE is given.
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  • 21
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    Circuits, systems and signal processing 7 (1988), S. 191-211 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract Parallel algorithms for solving geometric problems on two array processor models—the mesh-connected computer (MCC) and a two-dimensional systolic array—are presented. We illustrate a recursive divide- and-conquer paradigm for MCC algorithms by presenting a time-optimal solution for the problem of finding thenearest neighbors of a set of planar points represented by their Cartesian coordinates. The algorithm executes on a√n×√n MCC, and requires an optimalO(√n) time. An algorithm for constructing theconvex hull of a set of planar points and anupdate algorithm for thedisk placement problem on ann 2/3×n 2/3 two-dimensional systolic array are presented. Both these algorithms requireO(n 2/3) time steps. The advantage of the systolic solutions lies in their suitability for direct hardware implementation.
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  • 22
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    Circuits, systems and signal processing 7 (1988), S. 235-252 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract In this paper we show how systolic/wavefront arrays can be automatically designed and partitioned to solve problems of arbitrary size. Buffer memory and control of a resulting array is regular and simple, and is generated automatically. Also, the throughput of the array is matched with the I/O speed of the host to which it is to be attached. The approach strongly relies upon classical concepts in signal processing, such as signal flow graphs and state transition functional behavior. Some illustrative examples are included.
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  • 23
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    Circuits, systems and signal processing 7 (1988), S. I 
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  • 24
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    Circuits, systems and signal processing 7 (1988), S. 253-273 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract In this paper we introduce a class of efficient architectures for adaptive quadratic digital filters. These architectures are based on the LMS algorithm and use the rank compressed lower-upper (LU) triangular deomposition method. These architectures exhibit high parallelism as well as great modularity and regularity. We also consider affiliated VLSI array processing structures and compare these in terms of hardware cost and data throughput delay. For comparison purposes, the distributed arithmetic structures of adaptive quadratic filters are also included in the paper. Finally, the convergence performance of the adaptive quadratic filters is tested via benchmark simulation examples.
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  • 25
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    Circuits, systems and signal processing 7 (1988), S. 291-325 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract A new procedure is proposed for ARMA modeling of fourth-order cumulants and trispectrum estimation of non-Gaussian stationary random processes. The new procedure is applied to the identification of nonminimum phase systems for both phase and magnitude response estimation. It is demonstrated by means of comprehensive simulation examples that the ARMA approach exhibits improved performance over conventional trispectrum methods. ARMA model order selection criteria based on fourth-order cumulants are presented and their performance evaluated. The computational complexity of the ARMA and conventional trispectrum methods is also examined. The new procedure does not require knowledge of the non-Gaussian distribution.
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  • 26
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    Circuits, systems and signal processing 7 (1988), S. 327-343 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract This paper deals with the problem of adaptive beamforming in the presence of fully coherent (correlated) noise sources. Two different techniques are developed for minimizing the effects of coherent interference. The first method employs spatial interpolation of the array aperture, followed by spatial smoothing in order to decorrelate the desired signal and the interference. The second technique is based on a simple algebraic transformation for restoring the rank of the array signal correlation matrix, which is normally rank deficient in such situations. This technique is shown to work for nonuniform adaptive arrays as well. Extensive computer simulation results are presented to illustrate the effectiveness of the proposed techniques.
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  • 27
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    Circuits, systems and signal processing 7 (1988), S. 361-380 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract In this paper the notions of transmission zero, invariant zero, and structural zero (that is the geometric notion of zero) are extended to linear periodic discrete-time systems, as well as the notion of pole. Their meaning is clarified and their relationships stressed, thus extending the time-invariant theory. In particular, the invariant zeros and the structural zeros are shown to coincide, together with their multiplicities, and the former are shown to be independent of a linear state feedback. Moreover, the nonzero transmission zeros, the nonzero invariant zeros, and the nonzero poles are shown to be independent of time, together with their multiplicities. Some of these results are obtained with the help of the notions of reachability subspace and inner controllable subspace, which constitute a further development of the geometric theory for this class of systems.
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    Circuits, systems and signal processing 7 (1988), S. 411-411 
    ISSN: 1531-5878
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    Topics: Electrical Engineering, Measurement and Control Technology
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    Circuits, systems and signal processing 7 (1988), S. 381-408 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract We consider the problem of optimal filtering of a scalar diffusion process measured by a monotone nonlinear sensor in a low-noise channel. The specific sensors considered are of the formh n(x)=¦x¦n sgn(x). This case represents a wide class of sensors with a critical inflection point, since it is the leading term in Taylor's expansion of the measurement function in the critical region. We give for the first time a formal asymptotic approximation of the conditional and of the mean square estimation errors of the optimal filter as interpolation formulas. We also construct an asymptotic approximation to the optimal filter and compare its performance with that of a constant gain filter.
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    Circuits, systems and signal processing 7 (1988), S. 459-466 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract A generalized Leverrier's algorithm is developed for the computation of the transfer function matrix of a singular two-dimensional discrete-time system. The algorithm is a recursion in terms of the original system matrices, and does not require the inversion of a polynomial matrix.
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    Circuits, systems and signal processing 7 (1988), S. 427-457 
    ISSN: 1531-5878
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    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract In this paper a new method to image restoration problems is proposed. The main result is the definition of an image model which does not require knowledgea priori of the image autocorrelation function or the use of identification estimation algorithms. The basic hypothesis is that the image can be modeled as an ensemble of two-dimensional differentiable surfaces. In this case the signal and its partial derivatives with respect to the spatial coordinates can be assumed to be the state vector and an image state space representation is directly obtained. A semicausal dependence model is adopted, it is embedded in a strip recursive scheme suitable to the Kalman filter application. Numerical results, concerning three different kinds of images, show high performances of the algorithm.
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    Circuits, systems and signal processing 7 (1988), S. 481-510 
    ISSN: 1531-5878
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    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract This paper describes a method of fault diagnosis for large interconnected circuits in which the number of faults is limited to, say,n f where it is possible thatn f exceeds the number of output measurements,n o. The problem and its solution are formulated in the context of a frequency domain tableau based on the component connection model of a circuit/system. The paper describes Jacobian tests for diagnosability whenn f≥n o and states a full parameter diagnosability test as a corollary to the main theorem. An algorithm is developed for the identification of faulty parameters in this limited fault case. Finally, examples, including a 26-parameter video-amplifier circuit, illustrating the technique are given.
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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 34 (1988), S. 232-241 
    ISSN: 1439-0574
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Description / Table of Contents: Summary To evaluate the feeding pressure exerted by roe deer(Capreolus capreolus), on vegetation, the biomass within reach of feeding animals was measured in the Chizé forest (Deux Sèvres, France) in 2 types of woodland (oak and beech), and for 2 levels of population density: a high density of 20 animals/100 hectares (inside a fenced reserve) and a low density of 5 animals/100 hectares (outside the reserve). The biomass of vegetation was sampled 3 times (spring, end of summer, winter) using the same procedure each time. In the oakwood, total biomass was greater in areas of low density population than in areas with high density. In the beechwood, there was no significant difference in total biomass according to population density. In all cases, the maximum total biomass was observed in the spring sampling. Some differences were noted in the composition of the vegetation between the area inside the game reserve and the area outside the reserve.Hedera helix was very abundant outside the reserve andRuscus aculeatus and mosses were more frequent in the reserve. The feeding impact of roe deer on vegetation determines a change in the floral equilibrium permitting an increase in the abundance of plants not eaten by roe deer and causing a decrease of plants favoured by the deer.
    Abstract: Résumé Dans le but d'évaluer l'impact du chevreuil sur la végétation, la biomasse accessible à ces animaux a été évaluée dans 2 types d'association végétale (une chênaie et une hêtraie) pour 2 niveaux de densité de population dans la forêt domaniale de Chizé (Deux Sèvres, France): forte densité (20 animaux pour 100 hectares) dans la Réserve Nationale de Chasse et faible densité (5 animaux pour 100 hectares) à l'extérieur de la Réserve. Trois séries de relevés ont été effectuées avec la même méthode (printemps, fin de l'été, hiver). Dans la chênaie, la biomasse totale est plus importante en faible densité qu'en forte densité. Ce phénomène n'est pas observé dans la hêtraie. Dans tous les cas, elle est maximale au printemps. Des differences de la composition spécifique de la végétation sont observées entre la zone en réserve et l'extérieur. Le lierre(Hedera helix) est très abondant hors de la réserve. Le fragon(Ruscus aculeatus) et les mousses sont plus développées dans la réserve. L'impact du chevreuil se traduirait par une modification de la composition de l'équilibre végétal, le développement des espèces refusées par cet animal et la raréfaction des espèces appétentes.
    Notes: Zusammenfassung Zur Beurteilung des Einflusses des Rehwildes (Capreolus capreolus) auf die Vegetation wurde die diesen Tieren zugängliche Biomasse in zwei Waldgesellschaften (Eichen- und Buchenwald) mit unterschiedlicher Populationsdichte (hohe Dichte: 20 Stück/100 ha; niedrige Dichte 5 Stück/100 ha) im Staatsforst von Chizé (Frankreich) erhoben. Drei Probeaufnahmen wurden mittels der gleichen Methode (Frühjahr, Spätsommer, Winter) durchgeführt. Die Gesamtbiomasse liegt im Eichenwald höher bei niedriger als bei starker Populationsdichte. Gleiches Phänomen kann im Buchenwald nicht festgestellt werden. In allen Fällen wird die maximale Biomasse im Frühjahr erreicht. Unterschiede in der spezifischen Vegetationszusammensetzung zwischen Gehege-und Freiflächen konnten beobachtet werden. Efeu (Hedera helix) ist außerhalb des Geheges reichlich vorhanden. Segge (Ruscus aculeatus) und Moosarten sind im Gehege stark vertreten. Der Einfluß der Rehe wird durch die Veränderung des Vegetationsgleichgewichtes, der Entwicklung von verweigerten und Seltenwerden der bevorzugten Pflanzenarten, eindeutig.
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    European journal of wildlife research 34 (1988), S. 262-276 
    ISSN: 1439-0574
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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    European journal of wildlife research 24 (1978), S. 182-186 
    ISSN: 1439-0574
    Source: Springer Online Journal Archives 1860-2000
    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 
    ISSN: 1439-0574
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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    European journal of nutrition 27 (1988), S. 71-74 
    ISSN: 1436-6215
    Source: Springer Online Journal Archives 1860-2000
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    European journal of nutrition 27 (1988), S. 57-70 
    ISSN: 1436-6215
    Keywords: Retinol ; Vitamin-A-Status ; Vitamin-A-Serumbestimmung ; Hypervitaminose A ; Hypovitaminose A ; retinol ; vitamin A status ; vitamin A serum determination ; hypervitaminosis A
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary As demonstrated in the literature on vitamin A metabolism and homeostasis of retinol in serum, the concentration of retinol in serum is regulated very exactly if the liver stores are within the physiological range (20–300 Μg/g liver). Therefore, the serum level indicates the status of vitamin A storage only if there is an extreme depletion or overconsumption of vitamin A. At marginal depletion, however, there is damage to peripheral tissue before changes in the vitamin A level in serum occur. At the beginning of hypervitaminosis A, changes in the level of vitamin A in serum also occur later. Therefore, the determination of vitamin A in serum gives no information on the adequacy of liver reserves for judging the necessity of a substitution.
    Notes: Zusammenfassung Wie viele Arbeiten über den Vitamin-A-Metabolismus und Retinol-Serumhomöostase zeigten, unterliegt die Retinol-Serum-Konzentration im physiologischen Bereich der Leberreserven (20–300 Μg/g Leber) einer strengen Regulation. Daher gibt der Serumspiegel nur bei einem extremen Mangel oder bei übersättigung mit Vitamin A Auskunft über die Speichervorkommen. Im Grenzbereich, dem marginalen Mangel, kommt es aber schon zur Schädigung peripherer Gewebe, bevor sich der Retinol-Serumspiegel verändert. Auch bei beginnender Hypervitaminose A zeigen sich Veränderungen im Serumspiegel erst zu einem späteren Zeitpunkt. Daher ist die Bestimmung des Vitamin-A-Serumspiegels kein guter Indikator für den Vitamin-A-Status und die Beurteilung der Notwendigkeit einer Substitution.
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    ISSN: 1436-6215
    Keywords: mental retardation ; obesity ; body size ; serumlipids ; low-energydiet ; geistige Behinderung ; Übergewicht ; Serumlipide ; kalorienarmeDiät
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Geistig behinderte, übergewichtige Patienten, die in einem geschlossenen Kollektiv lebten, verwendeten neun Monate lang eine kalorienreduzierte Kost (4,2–4,6 MJ). Während der Untersuchungsperiode war eine Körpergewichtsverminderung von 13±5,5 kg bei den Männern und 16±2,6 kg bei den Frauen zu beobachten. Vor der Diättherapie und im neunten Monat wurden anthropometrische Untersuchungen durchgeführt. Wir konnten feststellen, daß der prozentuale Anteil des Körperfetts, nach BMI berechnet, deutlich abnahm. Anhand der Hautfaltmessungen dagegen zeigte sich diese Verminderung weniger deutlich. Das ist Wahrscheinlich auch auf die Schwierigkeiten zurückzuführen, die während der Messungen infolge körperlicher Mißbildungen auftraten. Die klinischen Laboruntersuchungen, die vor Beginn der diätetischen Behandlung sowie im vierten und siebten Monat durchgeführt wurden, weisen darauf hin, daß eine kalorienarme Kost mit ausgeglichenem Nährstoff- bzw. Eiweißgehalt dem Eiweißstoffwechsel nicht schadet und den Triglycerid- und Cholesterinspiegel im Serum günstig beeinflußt, andererseits aber eine ungewünschte Cholesterinverminderung in der HDL-Fraktion verursacht.
    Notes: Summary Mentally retarded obese in-patients were fed by low-energy diet (4.2–4.6 MJ) for 9 months. During this period, an average of 13±4.5 kg loss of body mass occurred in men and 16±2.7 kg in women. Anthropometric measurements were performed before starting the dietotherapy and in the ninth month. Changes of body fat could be followed well when calculated according to BMI. Less reliable results were obtained with skinfold thickness Measurements, presumably due to body deformities. Results of clinical laboratory tests, which were carried out before starting the dietotherapy and in the fourth and seventh months, suggested that a low-energy-containing diet with balanced nutrient content and adequate protein intake did not lrnpair protein metabolism, favourably affected serum triglyceride and cholesterol levels, but resulted in an unfavourable decrease in the HDL-cholesterol content.
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    European journal of nutrition 27 (1988), S. 126-136 
    ISSN: 1436-6215
    Keywords: marginalerZinkmangel ; humoraleImmunität ; Immunglobuline der Ratte ; marginalzinc deficiency ; humoralimmunity ; ratimmunoglobulins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary The purpose of this experiment was to examine the effects of a marginal zinc deficiency on serum immunoglobulin (Ig) IgM and IgG1 levels. 60 weanling female Sprague-Dawley rats were divided into six groups of ten animals each. Two control groups (73.7 ppm Zn) and two zinc-deficient groups (4.3 ppm Zn) were fed a semisynthetic casein diet ad libitum. The animals of two further groups received the control diet (73.7 ppm Zn) pair-fed to the zinc-deficient animals. After 15 days the rats of one group of each treatment were infected i.m. with a single injection (0.2 ml) of a bovine enterovirus, apathogenous to rats. 3 weeks later, all rats were anesthetized with ether and decapitated. Infection of the rats with the bovine enterovirus had no effect on the serum immunoglobulin level. The marginal zinc deficiency did not alter the IgM and IgG1 serum concentrations at all either. It remains to be examined whether other Ig-classes will react to marginal zinc deficiency. Also, the effect of severe zinc deficiency on the humoral immune system must be studied.
    Notes: Zusammenfassung In einem Versuch mit 60 weiblichen entwöhnten Sprague-Dawley-Ratten wurde geprüft, ob marginaler Zinkmangel direkte Auswirkungen auf die Serumimmunglobulinspiegel IgM und IgG1 zeigt. Die Ratten wurden in 6 Behandlungsgruppen zu je 10 Tieren eingeteilt. Zwei Kontrollgruppen (73,7 ppm Zn) und die beiden marginalen Zinkmangelgruppen (4,3 ppm Zn) wurden ad libitum mit einer halbsynthetischen Diät auf Caseinbasis versorgt. Die Tiere zweier weiterer Gruppen erhielten pair-fed zu den Mangeltieren eine Kontrolldiät mit ebenfalls 73,7 ppm Zn. 15 Tage nach Verfüttern dieser Diäten wurde jeweils eine Gruppe der unterschiedlich versorgten Tiere mit einem für Ratten apathogenen Rinderenterovirus (0,2 ml pro Ratte) i.m. infiziert. 3 Wochen später wurden alle Tiere mit Ether betäubt und dekapitiert. Die Infektion der Ratten mit dem bovinen Rinderenterovirus blieb ohne Einfluß auf den Immunglobulin-(Ig-)Spiegel. Auch der marginale Zinkmangelzustand, wie er in der vorliegenden Untersuchung auftrat, führte bei den Versuchstieren zu keinen Veränderungen in der IgM- und IgG1-Konzentration des Serums. Es bleibt zu untersuchen, ob andere Immunglobulinklassen eher auf marginalen Zinkmangel ansprechen oder welchen Einfluß ein extremer Zinkmangel bei der Ratte ausübt.
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    European journal of nutrition 27 (1988), S. 201-205 
    ISSN: 1436-6215
    Source: Springer Online Journal Archives 1860-2000
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    ISSN: 1436-6215
    Keywords: cholesterol ; triglycerides ; lipoproteins ; ω 3 fatty acids ; Cholesterol ; Triglyceride ; Lipoproteine ; ω-3-Fettsäuren
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung In einem Kurzzeit-Experiment wurde an gesunden, normolipidämischen Probanden geprüft, ob durch einen mäßig hohen Fischverzehr der Gehalt an Plasma- und Lipoproteinlipiden gesenkt werden kann. 8 Teilnehmer aßen eine Woche lang täglich 100 g Makrele (entsprechend etwa 2,5–3 g ω-3-Fettsäuren). Die Triglycerid-Konzentrationen im Plasma und in den VLDL und LDL waren nach der Fischdiät um 40, 46,7 und 38,5 % niedriger als zu Beginn des Experiments. Die Plasmacholesterol-Konzentration war nur geringfügig erniedrigt, das Verhältnis HDL/Gesamt-Cholesterol aber signifikant erhöht. Die Studie zeigt, daß eine moderate Steigerung des Fischverzehrs bei gesunden, normolipidämischen Probanden innerhalb einer Woche — selbst auf der Basis einer nicht strikt kontrollierten Diät — die Lipidspiegel verändern kann.
    Notes: Summary The effect of mackerel consumption on plasma and lipoprotein lipid concentrations was studied in a seven-day experiment in eight healthy, normolipidemic subjects. Participants ate about 100 g mackerel (corresponding to about 2.5–3 g ω3 fatty acids daily. The mean triglyceride concentrations in total plasma, VLDL, and LDL were significantly reduced by 40, 46.7, and 38.5 % respectively after fish consumption. There was also a small (non-significant) reduction of plasma cholesterol and a (significant) increase of the ratio of HDL/total plasma cholesterol. These data show that a moderately increased intake of ω-3 fatty acids by fish food can change lipid characteristics in healthy normolipidemic individuals within a short-time period, even on a free diet.
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    European journal of nutrition 27 (1988), S. 236-243 
    ISSN: 1436-6215
    Keywords: cholesterol feeding ; spermatogenesis ; Leydig's cell ; VLDL/LDL-cholesterol ; Cholesterinfütterung ; Spermatogenese ; Leydig-Zellen ; VLDL/HDL-Cholesterin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Cholesterinfütterung über 120 Tage beeinträchtigt bei männlichen Ratten und Kaninchen die Testikularfunktion. Die Produktion von sekundären Spermatozyten wird bei Ratten und Kaninchen um 26,1 % bzw. 46,9 % reduziert. Ferner kommt es zu einer signifikanten Reduktion der Spermatid-Population, der Samenkanälchen und der Dimension der Zellkerne der Leydig-Zellen. Im Aortenendothel finden sich bei der Ratte einige Alterationen, beim Kaninchen dagegen voll ausgeprägte atherosklerotische Plaques. Gesamtcholesterin, Triglyceride und Phospholipide in den Testes nehmen zu, während der Gehalt an Glykogen in den Testes abnimmt. Die Cholesterinkonzentrationen im Serum sind bei Ratten dreifach, bei Kaninchen siebenfach erhöht, wobei LDL-Cholesterin ansteigt, der Quotient HDL-Cholesterin/Gesamtcholesterin dagegen signifikant abfällt. Als Schlußfolgerung ergibt sich, daß Hypercholesterinämie neben dem Aortenepithelium auch die Hodenfunktion beeinträchtigt.
    Notes: Summary Cholesterol fed to male rats and rabbits for 120 days impaired testicular function. The production of secondary spermatocytes in rats and rabbits was reduced by 26.1% and 46.9%, respectively. There was significant reduction in spermatid cell population, seminiferous tubules, and Leydig's cell nuclear dimensions. In rats aortic endothelium showed some alterations while in rabbits full-blown atherosclerotic plaque containing a necrotic core and a proliferative fibrous cap was found. Total cholesterol, triglycerides and phospholipids of the testes were increased whereas, testicular glycogen was significantly reduced. Three- and sevenfold increases were noticed in the serum cholesterol levels of rats and rabbits. The LDL cholesterol values were increased while the HDL cholesterol/Total cholesterol ratio was significantly decreased (P〈0.001). It is concluded that hypercholesteromia affects the testicular function and aortic endothelium.
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    European journal of nutrition 27 (1988), S. 244-251 
    ISSN: 1436-6215
    Keywords: Phytinsäure/Zink-Quotient ; Vollkornbrot ; Knäckebrot ; Zink alkalische ; Phosphatase ; phytic acid/zinc ratio ; wholemeal bread ; crispbread ; zinc alkaline ; phosphatase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary A study was untertaken to determine whether the reduction of the molar phytic acid/zinc ratio by enrichment of wholemeal and crispbread with zinc improves zinc availability to the same extent as does the reduction of phytic acid in whole meal cereal products. For three weeks, five diets (three samples of wholemeal bread and two samples of crispbread)) were fed to growing rats. Significant increases in bone-zinc deposition and activity of serum alkaline phosphatase were induced by those bread samples in which the phytic acid/zinc ratio had been lowered either by enrichment with zinc or by reduction of phytic acid (enzymatic hydrolysis by adjusting the pH-value of the dough with lactic acid) when compared with untreated bread samples. Weight gain of the animals differed little between the groups. The results suggest that it is possible to improve zinc availability in wholemeal cereal products high in phytate by enrichment with zinc.
    Notes: Zusammenfassung Es wurde geprüft, ob die Verringerung des molaren Phytinsäure/Zink-Quotienten in Vollkorn- oder Knäckebrot mit einem hohen Phytinsäuregehalt durch Anreicherung mit Zink die gleiche günstige Wirkung auf die Zinkverfügbarkeit hat wie die Reduzierung der Phytinsäure in Vollkornprodukten. In einem dreiwöchigen Versuch wurden 5 Diäten (3 Schrotbrot- und 2 Knäckebrotproben) an wachsende Ratten verfüttert. Die Proben, in denen der Phytinsäure/Zink-Quotient durch Anreicherung mit Zink oder durch Reduzierung der Phytinsäure (enzymatische Hydrolyse durch Einstellung des pH-Wertes des Teiges mit Milchsäure) verringert war, bewirkten eine signifikante Erhöhung der Zinkeinlagerung im Femur und der Aktivität der alkalischen Phosphatase im Serum der Tiere im Vergleich zu unbehandelten Brotproben. Das Wachstum der Tiere zeigte nur geringe Unterschiede zwischen den 5 Gruppen. Die Ergebnisse lassen erkennen, daß eine Verbesserung der Zinkverfügbarkeit in Getreidevollkornprodukten mit hohem Phytatgehalt durch Anreicherung mit Zink erzielt werden kann.
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    European journal of nutrition 27 (1988), S. 252-265 
    ISSN: 1436-6215
    Keywords: cow'smilk ; humanmilk ; high performance liquid chromatography (HPLC) ; infant formulas ; phospholipids ; Frauenmilch ; Hochdruck-Flüssigkeitschromatographie (HPLC) ; Kuhmilch ; Phospholipide ; Säuglingsnahrungen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Mit Hilfe einer speziell hierfür entwickelten (6) Hochdruckflüssigkeitschromatographie-Methode (HPLC) wurde der Phospholipidgehalt (PL) von Frauenmilch, Kuhmilch und verschiedenen Säuglingsnahrungen bestimmt. Die Untersuchungen zeigen, daß der Gehalt an Phosphatidylinositol (PI), Phosphatidyläthanolamin (PE), Phosphatidylcholin (PC) und Sphingomyelin (SP) durch Homogenisieren und Pasteurisieren von Kuhmilch nicht verändert wird. Der Gehalt an Phosphatidylglycerol (PG) liegt hier, wie bei der Frauenmilch, unter der Nachweisgrenze. Auch bei den anderen untersuchten PL konnten zwischen Frauen- und Kuhmilch keine nennenswerten Unterschiede festgestellt werden. Der Gehalt einiger PL verändert sich im Verlauf der Spätschwangerschaft und der Post-partum-Periode charakteristisch. So liegt der Gehalt an PI, PC und SP in der Vormilch deutlich über dem Gehalt reifer Frauenmilch. Bereits vor Beginn der Wehen zeigen alle PL einen mehr oder weniger scharfen Abfall. So verliert Vormilch vor der Geburt 70 % des Gehaltes, den PL-Proben sechs Wochen vor der Geburt zeigen. Die PG-Gehalte sind allgemein in der gesamten Beobachtungsperiode sehr niedrig. Im Gegensatz zu den anderen Parametern erholt sich der PC-Gehalt drei Wochen nach der Geburt wieder, was als Ausdruck eines endogenen Surfactant-Regelmechanismus betrachtet werden kann. Weiterhin wurden 13 verschiedene Säuglingsnahrungen im Vergleich mit Kuhmilch und Frauenmilch untersucht. Dabei wurden teilweise erhebliche Unterschiede zwischen adaptierter Milch, teilweise adaptierter Milch und Spezialnahrungen, aber auch innerhalb dieser Gruppen, gefunden. Keines der bestimmten PL konnte in allen Säuglingsnahrungen nachgewiesen werden. Mit Ausnahme einiger Milupa-Säuglingsnahrungen war der PG-Gehalt allgemein niedrig. PE und PI wurden nur in einigen Spezialnahrungen nicht gefunden. Die meisten Säuglingsnahrungen enthalten hohe Gehalte an SP, die teilweise höher als der Gehalt an PC liegen. Allgemein kann gesagt werden, daß die untersuchten Säuglingsnahrungen z.T. wesentlich andere Phospholipidmuster als Frauen- und Kuhmilch aufweisen und daß zwischen einzelnen Säuglingsnahrungen erhebliche Unterschiede in der Zusammensetzung bestehen. In den meisten der untersuchten Nahrungen ist der Phospholipidgehalt so hoch, daß er durchaus als Phospholipidquelle für das Neugeborene genutzt werden kann.
    Notes: Summary The phospholipid (PL) content of human milk, cow's milk, and various infant formulas was determined by recently developed high performance liquid chromatography (6). As the examinations promised, the content of phosphatidylinositol (PI), phosphatidylethanolamine (PE), phosphatidylcholin (PC), and sphingomyelin (SP) was not changed by homogenization and pasteurization of cow's milk. Levels of phosphatidylglycerol (PG) were below the detection limit. Furthermore it has been proved that human milk and cow's milk are more or less identical in PL content. Some of the PL in human milk varies during the course of pregnancy and postpartum. PI, PC, and SP content in the prepartum mammarial secretion lies above the average content of mature human milk after delivery. Before the contractions start, all the PL examined show a more or less considerable decrease. PC drops to 30 % of the value at the beginning of the examination six weeks before delivery. PG contents are very low throughout the whole period. Contrary to the others, PC content recovers three weeks after delivery, which may be the result of the endogenous surfactant replacement system. To compare PL content with human milk and cow's milk, 13 different infant formulas have been examined. There are considerable differences to be found in and among adapted milk, partially adapted milk, and special formulas. None of the PL examined could be found in all the infant formulas, where PG content was usually low, except in some Milupa formulas. PE and PI were not to be found in some special formulas. Most of the formulas contain high amounts of SP, in some cases higher than the amount of PC. To a certain extent infant formulas contain a considerably greater amount of other PL concentrations than human milk and cow's milk. In most of the formulas examined the PL content is generally so high, that it can be used as a source of PL for the newborn.
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    European journal of nutrition 17 (1978), S. 124-127 
    ISSN: 1436-6215
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
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  • 49
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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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  • 50
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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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    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 27 (1988), S. 119-125 
    ISSN: 1436-6215
    Keywords: vitamin A ; development offetal heart ; DNA ; RNA ; protein ; rat ; Vitamin A ; Entwicklungfetaler Organe ; DNA ; RNA ; Protein ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Die Auswirkung einer beschränkten Vitamin-A-Zufuhr bei trächtigen Ratten auf die biochemische Entwicklung des fetalen Herzens wurde untersucht. Der Vitamin-A-Status der weiblichen Ratten wurde durch Angebot von geringen, mittleren und hohen Mengen an Vitamin A während Trächtigkeit und Säugeperiode verändert (6,40 und 100 μg Retinol/Tag/kg Körpergewicht). Der Vitamin-A-Status der Muttertiere verursachte eine Veränderung in der Entwicklung des fetalen Herzens in bezug auf Gewebegewicht, DNA-, RNA- und Proteingehalt sowie der Biosynthese von DNA und Proteinen aus jeweils [3H]-Thymidin und [3H]-Leucin. In den sich entwickelnden Rattenherzen wurde eine dosisabhängige Wirkung von Vitamin A auf den DNA-, RNA- sowie den Proteinstoffwechsel beobachtet. Eine angemessene Versorgung der Muttertiere mit Vitamin A ist entscheidend für die normale Entwicklung fetaler Organe.
    Notes: Summary The effect of restricted vitamin A supply to the mother on the biochemical development of the heart in rats has been studied. The vitamin A status of female rats was varied by supplying low, medium and adequate amounts (6, 40, 100 μg retinol/day/kg body weight respectively) of vitamin A during pregnancy and suckling. The vitamin A status of the mother caused an alteration in the developmental pattern of fetal heart in parameters of tissue weight, DNA, RNA and protein contents and the biosynthesis of DNA and protein from [3H]-thymidine and [3H]-leucine respectively. A dose-dependent effect of vitamin A on the metabolism of DNA, RNA and protein was observed in the developing rat hearts. Hence, emphasis should be given to the adequate availability of vitamin A to dams for the normal growth and development of fetal organs.
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  • 53
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    European journal of nutrition 27 (1988), S. 155-169 
    ISSN: 1436-6215
    Keywords: acesulfame ; anion transport ; cyclamate ; saccharin ; streptococcus mutans ; sweetener ; Acesulfam ; Anionentransport ; Cyclamat ; Saccharin ; Streptococcus mutans ; Süßstoff
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung In einem 1-Octanol/Phosphatpuffersystem war Saccharin viel stärker lipophil, als aus seiner Dissoziationskonstante abgeleitet werden kann; diese dagegen bestimmte die Verteilung von Acesulfam und Cyclamat. Die Aufnahme von Saccharin in S. mutans ergab eine 30-bis 40fache Anreicherung dieses Süßstoffs gegenüber dem Medium. Acesulfam und Cyclamat verteilten sich zwischen Zellen und Medium im wesentlichen nach einem diffusionskontrollierten Vorgang. Die Aufnahme von Saccharin in S. mutans erwies sich als von einer gleichzeitigen Zuckerfermentation abhängig, ferner auch vom Außen-pH, von der Süßstoff-Konzentration und der Zellzahl. Ohne Glykolyse — z. B. aufgrund des Verbrauchs der vorgelegten Saccharose, wegen eines zu sauren pH-Wertes im Medium oder wegen Anwesenheit von Glykolyse-Inhibitoren — war die Aufnahme von Saccharin ebenso nur diffusionskontrolliert wie die des Acesulfams und die des Cyclamats. Durch Zugabe von L-Lactat ins Medium, wodurch die Richtung des Lactat-Gradienten umgekehrt wurde, war die Saccharin-Aufnahme gehemmt. Die Aktivierungsenergie der Saccharin-Aufnahme betrug rund 18 kJ/Mol, während die Glykolyse selbst je nach Versuchsbedingungen 82–98 kJ/Mol erforderte. Bis zu 100 attomol Saccharin wurden pro Bakterienzelle gefunden. Daraus läßt sich schließen, daß die Cytomembran von S. mutans an der Vermittlung der Hemmeffekte von Saccharin auf die Zuckervergärung — durch Antiport des Intensivsüßstoffs in die Bakterienzelle im Austausch gegen Lactat — beteiligt ist.
    Notes: Summary In a 1-octanol/phosphate buffer system, saccharin was much more lipophilic than would be inferred from its dissociation constant which, however, determined the partition behavior of acesulfame and cyclamate. The uptake of saccharin into Streptococcus mutans led to a 30 to 40-fold higher concentration of this intense sweetener within cells than in the incubation medium. Acesulfame and cyclamate were distributed between cells and medium essentially in a diffusioncontrolled manner. The uptake of saccharin into S. mutans was found to depend strongly on simultaneous sugar fermentation, and in addition, on external pH, sweetener concentrations, and cell densities. Without glycolysis, caused, for example, by an exhaustion of added sucrose, too acidic external pH, or the addition of glycolysis inhibitors, the uptake of saccharin was diffusion-controlled as in the case of acesulfame and cyclamate. The uptake of saccharin was inhibited by a reversal of the direction of the lactate gradient from in → out to out → in. The activation energy of saccharin uptake into glycolyzing S. mutans was near 18 kJ/mol, while glycolysis itself required 82–98 kJ/mol as activation energy, depending somewhat on experimental conditions. Up to 100 attomol of saccharin per bacterial cell was observed. It was concluded that the cytomembrane of S. mutans was involved in mediating the inhibitory effects of saccharin by an antiport of saccharin into cells in exchange for lactate.
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    European journal of nutrition 17 (1978), S. 52-57 
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    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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  • 55
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    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 7 (1988), S. 1-17 
    ISSN: 1435-8107
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Purified fractions of soluble proteins from barley leaves have been shown to contain specific binding sites fortrans-zeatin, a natural cytokinin. Such binding is very strong in vitro in concentrated solutions of some salts (ammonium sulfate or potassium phosphate) with optimum at pH 7–8 and temperature within the range 0–20°C. The cytokinin-binding sites have high affinity for zeatin (Kd∼1.5·10−8 M) and low capacity corresponding to 1–1.5 pmol zeatin per milligram of initial soluble protein. Cytokinin binding is reversible; it is due to protein (or proteins) with molecular weight 40–45 kDa. This protein(s) does not bind3H-adenine and3H-abscisic acid. The ability of various compounds to displace3H-zeatin from its high-affinity binding sites is in strict accordance with their biological cytokinin activities. Other phytohormones as well as fusicoccin do not displace3H-zeatin from its binding sites. Specific zeatin binding is sensitive to heat, alkali, and pronase, but not to RNase treatment. The 150- to 200-fold purification of cytokinin-binding proteins was achieved by a combination of ammonium sulfate precipitation and Ultrogel AcA-54- and DEAE-cellulose chromatography. The zeatin-binding protein(s) from barley leaves is suggested to take part in cytokinin action in vivo.
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    Journal of plant growth regulation 7 (1988), S. 37-44 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effect of [(N-phenyl-N′-1,2,3-thidiazol-5-ylurea)] (thidazuron) on sprouting of potato (Solanum tuberosum L.) tubers and the role of ABA in bud break and subsequent bud growth were studied. Abscisic acid (ABA) was quantitated by enzyme-linked immunosorbent assay (ELISA) from the peel of potato tubers. The ELISA results were also validated by gas chromatography-electron capture detector and confirmed by gas chromatography-mass spectrometry and by a lettuce hypocotyl bioassay. The degree of rest in the tubers was associated with ABA content in the peel. Basal portion (where tuber was attached to mother plant) contained the highest amount of ABA. Thidiazuron reduced ABA content and induced potato tuber sprouting. Exogenously applied ABA stimulated growth of buds that had emerged from dormancy.
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    Journal of plant growth regulation 7 (1988), S. 19-26 
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract XE-1019 [(E)-1-(4-chlorophenyl)-4,4,-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol] was injected into bean plants (Phaseolus vulgaris L. ‘Black Valentine’) at doses of 0.1–1000 μg/plant and caused reduced height growth, fresh weight, and leaf area 7 days after treatment. The sprout growth of California privet (Ligustrium ovalifolium Hassk.) was inhibited 52% by 10 μg and growth was further suppressed as the dose was increased to 100 μg, without injury. The shoot growth of American sycamore (Platanus occidentalis L.) and yellow-poplar (Liriodendron tulipifera L.) was progressively inhibited after 3 months as the injected dose of XE-1019 was increased from 2.5 to 240 mg/tree. Neither species was injured. Growth of 1-year-old trees of ‘Golden Delicious’ apple (Malus domestica Borkh) was inhibited 28 days after injecting the stem with 2 mg of14C-labeled XE-1019. At this time, 2% of14C activity has been translocated into the new shoots and 3% was present in the xylem and phloem of the scion. From 96 to 99% of14C-activity found in the xylem and phloem and 92% in the new shoot tissue chromatographed with XE-1019. This indicates that little degradation of XE-1019 occurred during the initial inhibition period.
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    Journal of plant growth regulation 7 (1988), S. 27-36 
    ISSN: 1435-8107
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The relative growth inhibitory activities of paclobutrazol [(2RS,3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2(1,2,4-triazol-1-yl)pentan-3-ol]; XE-1019 [(E)-(1-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol]; flurprimidol [α-(1-methylethyl)-α-[4-(trifluoromethyloxy)-phenyl]-5-pyrimidine-methanol]; and triadimefon (a fungicide) [1-(4-chlorophenoxy)-3,3-dimethyl-1-(1H-1,2,4-triazol-1-yl)-2-butanone] were evaluated and compared by treating the root zone of young greenhouse-grown tissue-culture-propagated ‘Gala’ (Malus domestica Borkh.) trees. At 0.25 mg/plant, only XE-1019 significantly reduced new stem length and number, area, and dry weight of leaves after 115 days. Paclobutrazol and flurprimidol both significantly reduced growth compared to controls when applied at 0.5 mg/plant, but XE-1019 was more effective. All three gibberellin (GA) biosynthesis inhibitors effectively retarded growth at a dosage of 1 mg/plant. Triadimefon applied at 10 mg/plant had essentially no effect on growth, but at 50 and 100 mg/plant it caused significant but less dramatic growth retardation when compared with the GA inhibitors. Major differences in effectiveness among the triazole GA biosynthesis inhibitors may be due to longevity of effect as well as to extent of inhibition.
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  • 60
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The specific inhibitor of gibberellin biosynthesis, (2RS,3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)pentan-3-ol (paclobutrazol), inhibited germination ofAmaranthus caudatus L. seeds. Addition of gibberellic acid (GA3), 2-chloroethylphosphonic acid (ethephon), or 1-aminocyclopropane-1-carboxylic acid (ACC) effectively antagonized inhibition. Ethephon was found to be the most efficient antagonist. The transfer of seeds after 1 day's incubation in paclobutrazol to solutions of GA3 or ethephon reversed the inhibition, the effect increasing with increasing concentration of GA3 or ethephon. Seeds incubated in paclobutrazol for 5 days decreased sensitivity to GA3 and ethephon.
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    Journal of plant growth regulation 7 (1988), S. 67-75 
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Triapenthenol or RSW 0411 (B(-cyclohexalmethylene)-gamma-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol), a triazole plant growth regulator, applied preemergence as a separate broadcast application, protected tolerant and midtolerant soybean cultivars from metribuzin (4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one)-induced necrotic injury, and stabilized seedling fresh weight and dry weight loss to herbicide treatment. Soybean yields were not significantly reduced by triapenthenol treatment alone, but 1.12 kg ai/ha metribuzin and a 0.56 kg ai/ha triapenthenol plus 1.12 kg ai/ha metribuzin combination reduced crop yield averaged across cultivars.
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    Journal of plant growth regulation 7 (1988), S. 95-109 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In order to verify if epidermis integrity played a determinant role in epicotyl elongation induced by fusicoccin (FC), buffers at different pH's, and indoleacetic acid (IAA), we studied the short-term kinetics of elongation growth, the increase of fresh weight in long-term treatment, and the H+ excretion in intact, abraded, and peeled azuki bean epicotyl sections. We demonstrated that the epidermis is more sensitive to IAA, whereas the cortex is highly responsive to protons. Our data are consistent with the “acid growth theory.” In addition, our studies support the idea that the epidermis may be the tissue target for auxin, but its integrity is necessary for IAA-induced elongation.
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    Journal of plant growth regulation 7 (1988), S. 111-119 
    ISSN: 1435-8107
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Factors affecting the induction of ethylene synthesis in apple were investigated through their effect on the delay in ethylene production (DEP) in single fruits after harvest. DEP in Cox apples was not affected by temperature from 1 to 25°C, but in Golden Delicious, DEP was shorter below 12°C and above 20°C. An orchard treatment with daminozide increased DEP in apples held below 15°C or treated with ethylene after harvest. Experiments in which the temperature was changed after ethylene treatment showed that ethylene was less active at 5°C than at 15°C but that response to it could be equally rapid. The results suggest that endogenous ethylene is not regulatory prior to the onset of rapid ethylene synthesis.
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    Journal of plant growth regulation 7 (1988), S. 145-151 
    ISSN: 1435-8107
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Ent-kaurene (ent-kaur-16-ene) and squalene were analyzed in extracts of the shoots of three cultivars of rice (Oryza sativa L.) of 14 and 28 days of age by gas chromatography-mass spectrometry (GS-MS) and GC-selected ion monitoring (GS-SIM).Ent-kaurene occurred at approximate concentrations of 〈1 to 13 ng/g f.w. in 14-day-old plants and 26 to 147 ng/g f.w. in 28-day-old plants. Shoots of the dwarf cultivar Waito-C contained much lessent-kaurene than the other two cultivars at both developmental stages. The level ofent-kaurene in the dwarf cultivar Tan-ginbozu was similar to that in the normal cultivar Nihonbare at 14 days but was lower than in Nihonbare at 28 days. Trace amounts ofent-isokaurene (ent-kaur-15-ene) were also found in the extracts of all three cultivars of shoots at 28 days. Squalene occurred in approximate concentrations from as low as 19 ng/g f.w. in 28-day-old Waito-C shoots to as much as 626 ng/g f.w. in 14-day-old Nihonbare shoots. Both Tan-ginbozu and Waito-C shoots contained less squalene than Nihonbare shoots at both developmental stages.
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    Optical and quantum electronics 10 (1978), S. 83-93 
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    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract An analysis of the role of tunnelling rays in pulse propagation in graded-index fibres is presented. Tunnelling ray attenuation is handled by using the generalized parameter technique which allows attenuation coefficients to be dispensed with and relevant families of tunnelling rays to be identified. Results are given for impulse response pulse widths and shapes. Incorporation of tunnelling ray pulse contributions into the formalism for determining optimum refractive-index profiles is presented. For most cases, tunnelling ray effects are small, but significant corrections may be necessary when measurements are made on short lengths of fibre.
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    Optical and quantum electronics 10 (1978), S. 131-138 
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    Notes: Abstract Fifth order non-linear processes produced by a focused beam in metal vapour have been investigated experimentally. Evidence of saturation of fifth harmonic generation by picosecond laser pulses is reported.
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    Optical and quantum electronics 10 (1978), S. 107-117 
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    Notes: Abstract In this paper power coupling between two multimode optical fibres is investigated. A formalism (based on a geometrical approach) suitable for analysing any coupling configuration between fibres with any index profile and any radiance distribution is presented. The model is applied to obtain coupling losses both in uniformly excited parabolic- and step-index fibres, in the presence of all kinds of coupling errors. Numerical results of extensive utility are shown and useful asymptotic expressions of coupling efficiency, valid for small values of coupling error parameters, are derived together with some practical rules for error combination. Mention is also made of some experimental results we have obtained, which corroborate some previous assertions. The work can supply a useful tool in the design of joints and connectors between single fibres or optical cables.
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    Optical and quantum electronics 10 (1978), S. 153-161 
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    Notes: Abstract The photon drag and optical rectification response fromn-type gallium phosphide containing 2.4×1016 electrons cm−3 has been studied using laser sources at 10.61 and 2.83μm. By using different contact configurations, the existence of an additional electric field term in the propagation direction has been deduced. This field is shown to arise from the spatial derivatives of the photon drag and optical rectification field components caused by absorption of the radiation. The importance of this effect in detector design is considered.
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    Optical and quantum electronics 10 (1978), S. 171-178 
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    Notes: Abstract On the basis of the theory of coupled waves the amplitudes of the first-order diffracted waves and the diffraction efficiency is calculated for sequentially superposed phase gratings stored in dielectric reflection holograms. The investigations are restricted to the case of a fixed reference wave during recording and Bragg-angle incidence. By analogy to the transmission volume grating the coupling effects which appear between incident beams and diffracted waves give the possibility of building up beam-couplers and -splitters with certain coupling parameters determined by the recording process. Moreover, reflection gratings allow a favourable combination between coupling and reflecting properties and avoid the diffraction efficiency oscillations that are characteristic of transmission gratings. The performance of the reconstruction process with several waves simultaneously allows the tuning of the intensities of diffracted waves with dependence on amplitude or phase differences between incident beams.
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    Optical and quantum electronics 10 (1978), S. 181-183 
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    Optical and quantum electronics 20 (1988), S. 215-218 
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    Optical and quantum electronics 20 (1988), S. 273-278 
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    Notes: Abstract Conformal mapping is used to find the exact cut-off frequency of optical fibres with a dip in the refractive index. The exact mode field at cut-off is found to be a Bessel function of fractional order in the fibre core. The wider the dip is, the smaller the order.
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    Optical and quantum electronics 20 (1988), S. 257-262 
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    Notes: Abstract Through the use of a PFL (pulse-forming line) of conveniently changeable output impedance ZO, the electrical characteristics of a small volume-discharge of standard XeCl laser gas mix was studied. The impedance ZD from a 2×0.5×1(=1) cm3 discharge was found to be about 10Ω. A PFL of very low impedance is therefore rather inefficient in driving the discharge, because of the impedance mismatch and the slower current rise time. The data presented will be useful for the design of excimer lasers of small discharge volume, which find applications in serving as master oscillator or in high repetition rate operation.
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    Optical and quantum electronics 20 (1988), S. 283-300 
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    Notes: Abstract Three promising methods of improving temporal coherence in semiconductor lasers are reviewed. They are the development of novel laser devices, a technique of optical feedback and a technique of electrical feedback. The main discussion in this paper is focused on the technique of electrical feedback. The theoretical limit of frequency stability and recent experimental results are presented with respect to the following five subjects which are indispensable in the realization of highly coherent lasers: (a) frequency stabilization; (b) improvements in frequency reproducibility; (c) linewidth reduction; (d) frequency tracking; and (e) stable, accurate and wideband frequency sweep.
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    Optical and quantum electronics 20 (1988), S. 301-312 
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    Notes: Abstract There are many communication systems where the initial requirement is for moderate bit-rates and transmission distances, but where the ability to upgrade for future applications is very important. One way of designing such a system may be to combine readily available low-loss, high-bandwidth, single-mode fibres, designed for optimum performance atλ=1.3μm, with economical and reliable LEDs that emit light atλ=0.85μm. Such a system would no longer be single-moded; the consequences for fibre loss and dispersion of allowing the second mode to propagate are examined and used to predict the performance limits for a two-mode fibre system.
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    Optical and quantum electronics 20 (1988), S. 439-440 
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    Optical and quantum electronics 20 (1988), S. 475-483 
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    Notes: Abstract Bragg diffraction of light by rectangular phase gratings is considered, utilizing two-dimensional coupled-wave theory. Diffraction characteristics for two important cases of incident plane waves and Gaussian-profile beams are presented. It is shown that the diffraction properties depend on the following normalized parameters: the grating strength and a geometry parameter, the beam width and a displacement. Values of these parameters for the realization of both nearly transmitting and nearly reflecting regimes of diffraction are determined. The results obtained are used for the choice of the design parameters of integrated optic Bragg-type devices.
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    Optical and quantum electronics 20 (1988), S. 501-514 
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    Notes: Abstract Marcatili has proposed a class of graded-index (GRIN) tapers which do not radiate along their length. We investigated the splicing of such tapers to dissimilar waveguides, and derive a simple formula for the coupling efficiency, which clearly reveals the loss due to mismatch of spot-size and the curvature of the wavefronts.
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    Optical and quantum electronics 10 (1978), S. 9-15 
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    Notes: Abstract The optical processor proposed here consists basically of a coherent light source and two liquid crystal light valves, of which the first converts incoherent input patterns into coherent ones; the second operates entirely on coherent signals. It is shown that, if the valve operating point is correctly chosen and its transfer characteristic linearized, negative feedback is implemented around the second valve. The valves perform as active system components, because they modulate the source power by their driving signals. The linear dynamic range, modulation transfer function, and time transient behaviour of the system are briefly studied.
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    Optical and quantum electronics 10 (1978), S. 31-40 
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    Notes: Abstract The propagation of electromagnetic waves along a radially-inhomogeneous single-mode optical fibre with small index difference between core and cladding is studied. As in the case of the step-index fibre the propagation modes are weakly guided and their transverse fields are essentially polarized in one direction. The simple field descriptions and characteristic equation obtained here enable mode spot size and bending loss to be determined and are useful for practical design work of radially-inhomogeneous single-mode optical fibres.
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    Optical and quantum electronics 10 (1978), S. 17-29 
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    Notes: Abstract A two-dimensional real waveguide having a parabolic distribution of dielectric permittivity in the core region, flanked by cladding layers of constant refractive index is proposed as a model for a class of stripe-geometry injection lasers. The model is analysed by a series-solution method and results are given in terms of plots of normalized propagation constant, near-field filling factor, and far-field half-angle, all versus normalized frequency. These results are compared with those for the alternative models of (a) a homogeneous core waveguide, and (b) a medium whose dielectric permittivity varies quadratically with position throughout the whole of space. Apart from the series-solution method which was employed, a survey is included of other techniques available for analysing this waveguide model. These include perturbation theory, variational analysis, an exact solution of the scalar wave equation, and the WKB approximation.
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    Optical and quantum electronics 10 (1978), S. 53-60 
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    Notes: Abstract A ray theory based on the time-independent Fokker-Planck equation and the integration of time along ray trajectories provides analytical expressions for the average arrival time and spread of optical pulses propagating in randomly distorted, multimode, optical fibres. A clear physical picture emerges from the theory. The analytical expressions obtained for 〈t〉 and 〈t 2〉 coincide with the ones obtained by Olshansky from coupled-mode theory. The 〈t 3〉 and 〈t 4〉 moments of the impulse response are also calculated. Simple closed-form formulae are given for the step-index slab. The coupling between all modes is effectively taken into account in our ray theory.
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    Optical and quantum electronics 10 (1978), S. 61-82 
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    Notes: Abstract If light comes from a fixed direction and is to be collected onto an absorbing body which is approximately a point or a straight line, it is well known that a mirror of parabolic profile serves the purpose efficiently. If the light is diffuse, or its direction of incidence variable, or if the absorber is not approximately a point or a straight line, the parabola is less useful. This paper describes various particular collecting problems of this more general sort, together with efficient solutions for them, mainly by means of mirrors. The subject represents a corner of geometric optics little explored until recently, in which the notion of image formation scarcely appears. A unifying principle is the invariance of the ‘Lagrange-Helmholtz’ invariant, which is related to Liouville's theorem of Hamiltonian mechanics, and there is a unifying method of construction of the mirror profiles by means of string.
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    Optical and quantum electronics 10 (1978), S. 119-129 
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    Notes: Abstract Frequency stabilization using ‘mobile’ resonances is compared with that employing frequency modulation. Analogy with radio-frequency experiments leads to an optimization of the error signal. Offsets occuring in each case are discussed and additional offsets due to asymmetry are evaluated.
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    Notes: Abstract The influence of bulk losses and bulk dispersion on the propagation properties of surface waves in a radially inhomogeneous optical fibre is investigated numerically. The fibre is assumed to consist of a homogeneous cladding of either infinite or finite extent and a radially inhomogeneous core of higher permittivity. Bulk losses and dispersion in the core and cladding materials are presented by frequency-dependent complex permittivities. Power series expansions for the electromagnetic field quantities in the core have been used and the attenuation and the phase coefficients for the lower order modes have been calculated numerically. Results are presented for two different permittivity profiles, viz. the parabolic profile and the cubic spline profile, the cladding being of infinite extent in this case. Also, the influence of a finite cladding diameter on the numerical results is discussed.
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    Optical and quantum electronics 10 (1978), S. 139-151 
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    Notes: Abstract A simple model for the description of intracavity measurements of narrow absorption lines, developed in a previous paper [5], is generalized to include the effect of an inhomogeneous, in addition to the homogeneous, contribution to the laser line. Moreover, the standing wave effect which was previously treated only near threshold, is now properly studied well above threshold. It is shown that mode competition increases strongly, in the case of a large number of standing waves falling within the homogeneous laser line width, when one passes from the near threshold region to a high excitation level. The enhancement factor, however, is nearly independent of the intensity. Consideration is also given to the case of running waves.
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    Optical and quantum electronics 10 (1978), S. 163-170 
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    Notes: Abstract A composition-dependent single Sellmeier oscillator model, developed for predicting the refractive index against composition behaviour for the three binary glass systems, SiO2-B2O3, SiO2-P2O5 and SiO2-GeO2, is extended to a double Sellmeier oscillator model. The inclusion of both composition-dependent u.v. and i.r. terms in the Sellmeier equation has enabled the wavelength dispersive properties of optical glass fibres; refractive index, material dispersion and profile dispersion, to be computed for any composition, in any one of these three binary glasses. Theoretical calculations, for particular compositions, of material and profile dispersions are compared with experimental measurements on fibres of the same compositions, fabricated by chemical vapour deposition.
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    Optical and quantum electronics 10 (1978), S. 179-180 
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    Optical and quantum electronics 10 (1978), S. 184-185 
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    Optical and quantum electronics 10 (1978), S. 186-187 
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    Optical and quantum electronics 10 (1978), S. 195-203 
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    Notes: Abstract In the present paper the two-photon fluorescence (TPF) quenching produced by ruby lasers in dye is calculated on the basis of an electronic energy level system adapted for the special conditions of Rhodamine 6G. The model used here takes into consideration the action of competing one-photon processes. It will be shown that the reversed profile of TPF quenching in the overlap region is produced by the superposition of pulses with a time-dependent fluctuating phase as well as with a determinate quadratically time-dependent phase.
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    Optical and quantum electronics 10 (1978), S. 211-221 
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    Notes: Abstract A simplified theory for the performance of a digital optical receiver is developed. The receiver sensitivity is calculated in terms of circuit parameters, received and equalized pulse shapes, photodiode parameters and bit-rate. An excellent agreement between this theory and a more complicated analysis by Personick [4] is demonstrated. It is shown that the receiver sensitivity may be improved by launching reduced-width pulses into the fibre, particularly if fibre bandwidth is a significant limitation. Reduced-width pulses bring benefits in source power consumption and lifetime, and in timing recovery.
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    Optical and quantum electronics 10 (1978), S. 233-242 
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    Notes: Abstract The influence of the spectral width on the modulation behaviour of semiconductor injection lasers has been investigated theoretically on the basis of multimode rate equations. Analytical expressions are derived yielding an effective rate of spontaneous emission for a suitable description of dynamic characteristics of injection lasers. This effective emission rate may drastically exceed the total rate of spontaneous emission into the lasing modes. In the case of large signal modulation it has been shown that a large modulation depth as required for PCM-transmission also yields a considerable spectral broadening.
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    Optical and quantum electronics 10 (1978), S. 270-272 
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    Optical and quantum electronics 10 (1978), S. 273-276 
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    Optical and quantum electronics 10 (1978), S. 279-282 
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    Optical and quantum electronics 10 (1978), S. 283-291 
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    Notes: Abstract A novel method is proposed for selecting a single longitudinal mode in lasers with homogeneously broadened gain medium. Mode selection is achieved by the interaction of the standing cavity wave between the gain medium and a spatially saturated absorber. The theory is treated in detail for various geometric configurations including examples of important laser systems under continuous-wave operation, such as dye lasers.
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    Optical and quantum electronics 10 (1978), S. 323-330 
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    Notes: Abstract Mode coupling coefficients and coupling lengths are determined for multimode fibres with general index distributions in the case where random bending is the main cause of mode coupling. It is shown that the product of the coupling length and the coupling-induced loss is determined only by the shape of the index distribution, and that the coupling length of the focusing fibre is about four times longer than that of the step-index fibre when the coupling-induced losses of both fibres are equal.
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    Optical and quantum electronics 10 (1978), S. 341-351 
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    Notes: Abstract A single expression is presented for the power transmission coefficient of both step- and graded-index fibres, which is uniformly valid for all weakly tunnelling and refracting rays. Its accuracy is demonstrated in a comparison of the corresponding power attenuation coefficient for the step-index fibre with solutions to the electromagnetic boundary value problem.
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    Optical and quantum electronics 10 (1978), S. 361-363 
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