bluuebunny/crossref_metadata_2025 huggingface dataset:
Computer‐aided design of broad band reflection type amplifiers
Authors: Hammershaimb Edgar , Jeppesen Palle , Schjaer‐Jacobsen Hans
Published: June 2007

Microwave negative resistance reflection type amplifiers using stable transferred electron devices (TED's) are optimized by numerical optimization techniques programmed for an interactive graphic datascreen.

The small signal impedance of packaged TED's is measured on an automatic network analyzer. At the same time the impedance of unpackaged devices are obtained by on‐line correction for the package parasitics. The microwave circuit chosen is a multiple slug coaxial cavity, that is modelled by sections of lossy transmission lines including step susceptances. The measured small signal impedance of the packaged TED's and the cavity model are used in a direct optimization procedure, in which the calculated minimum gain in the prescribed frequency range is progressively maximized by adjusting the lengths, characteristic impedances and positions of the slugs. The computed results are displayed on a datascreen, which allows for interactive programming.

Comparisons of predicted amplifier performance for packaged and unpackaged devices form a basis for evaluating the possible degrading effect of package parasitics. The predictions of the computer‐aided design are in good agreement with experimental results. The design procedure imposes no restraint on the frequency variation of the active device impedance and is therefore useful for any stable broad‐banded negative resistance device.
Representation of noise in a particular type of linear n‐port network
Authors: Trofimenkoff F. N. , Treleaven D. H. , Bruton L. T.
Published: June 2007

A noisy linear N‐port network that can be represented by a noise‐free linear N‐port network with voltage and current noise sources at the ports is considered. If the linear N‐port network has a particular type of admittance matrix, it is possible to show that as many as N/2 when N is even and (N – 1)/2 when N is odd of the ports may be cleared of noise sources. The total number of unique representations of such a network is given for both the general case and for the case when a particular port or ports must be free of noise sources.
A gyrator‐rc double‐tuned band‐pass amplifier a step towards the integrated I.F. amplifier of a broadcast receiver
Authors: Atiya Fuad S. , Ibrahim I. Hanna
Published: June 2007

A gyrator‐RC twoport has the response of a conventional double‐tuned transformer‐coupled intermediate frequency amplifier stage. It uses two grounded gyrators and a π of capacitors to replace the transformer, and is designed for low sensitivity. Stages can be stagger‐tuned for a prescribed response. Suitable novel gyrator circuits are developed and measured. Measurements of the gyrator‐RC double‐tuned circuits give the known double‐tuned response with critical, over‐ and under‐critical coupling. A receiver circuit is suggested from the mixer to the detector in view of the gain, selectivity, A.G.C., swing and stability requirements. This circuit has to be reconsidered and possibly modified in later work for the purpose of integration.
Wave digital filters with reduced number of delays
Authors: Fettweis Alfred
Published: June 2007

A method is described which allows one to design wave digital filters with a reduced number of excess delays. It consists in first multiplying all impedances of the original LC‐filter either by ϕ = tanh (pT/2) or by 1/ϕ, similar to what has been proposed by Bruton, although for different reasons, for active filter design. The restrictions inherent in this latter case do not apply, but some structures are preferable over others. The excellent sensitivity properties of wave digital filters still hold; they can again be proved directly by a modification of the earlier concepts of pseudopower, pseudopassivity, and pseudo‐losslessness.
A new method for approximating passive network functions
Authors: Carlin H. J. , Kotiveeriah P.
Published: June 2007

The problem of efficiently approximating real frequency data, which represents either measured information of a physical system or idealized curves to be realized by rational positive real (PR) or bounded real (BR) functions is considered. The final rational function is guaranteed in advance to satisfy the conditions of physical realizability. All the steps of approximation are executed in the real frequency domain. Illustrative, numerical examples are given.
Low cost active low pass and band pass network
Authors: Attikiouzel J. , Linggard R.
Published: June 2007

An active RC filter circuit is described which realizes second order lowpass and bandpass functions. The filter uses two I.C. Operational amplifiers and four passive components to achieve accurate Q values up to 50. Its Q sensitivity to component values is found to be very low. The results of an exhaustive computer simulation are given which clearly define the operating limits of the circuit. A practical design technique is outlined, and a sixth order example is given.
The connection function–theory and application
Authors: Ransom M. N. , Saeks R.
Published: June 2007

An approach to circuit theory is presented wherein the connections are modelled as a system valued function of a system valued variable. It is shown that for a large class of circuits and systems that this nonlinear function can be viably represented by four matrices through which it may be readily manipulated, both theoretically and computationally. The elementary properties of the connection function are derived and the approach is illustrated through a number of applications. In particular, an explicit formula for the sensitivity of a circuit in terms of the sensitivity of its components is obtained; and a semi‐analytic solution to a class of CAD problems is formulated.
Short‐circuit admittance matrix synthesis with rc common‐ground networks and a minimum number of grounded finite‐gain phase‐inverting voltage‐controlled voltage sources
Authors: Stamenković Borivoje B.
Published: June 2007

A new procedure for the synthesis of active RC networks when grounded finite‐gain phase‐inverting voltage‐controlled voltage sources serve as active elements is developed. It is proved that an arbitrary n × n matrix of real rational functions of the complex frequency variable can be realized as the short‐circuit admittance matrix of a grounded transformerless active RC n‐port network containing (n+1) grounded finite‐gain phase‐inverting voltage‐controlled voltage sources (VCVSs). In general all the (n+1) grounded VCVSs are necessary.

The structure proposed to prove a general theorem is later simplified for the realization of a restricted but important class of real rational matrices to obtain considerable savings in the computation volume and in the number of passive components used for the realization of the network.

Examples are given to illustrate presented synthesis procedures.
Finite band approximation for distributed and digital selective linear phase transfer functions
Authors: Fahmy M. F. , Rhodes J. D.
Published: June 2007

Using the recently derived formula which interpolates to a linear phase response at equidistant frequency intervals in a distributed variable, transfer functions are constructed which exhibit flat amplitude and linear phase characteristics over a finite band.

Reciprocal realizations for the implementation in distributed structures are derived, together with a non‐reciprocal version ideally suited for recursive digital filter design. Their superiority over the corresponding maximally flat solutions is also illustrated.
Transfer matrix realization using RC:GIC Networks
Authors: Mitra S. K.
Published: June 2007

A general synthesis procedure for realizing any stable voltage transfer matrix using current‐conversion type generalized impedance converter (GIC)s is outlined. Each row of the transfer matrix is realized separately as an M‐input, single‐output grounded RC:GIC network where M is the number of columns in the transfer matrix. The realization procedure is illustrated by an example. Using this approach, a second‐order filter has been obtained capable of realizing simultaneously highpass, band‐pass and low‐pass transfer functions and using fewer passive components and operational amplifiers than the popular state‐variable realizations. The various sensitivities of the second‐order realizations are low and comparable to the state‐variable realizations. A similar method can be developed for current transfer matrix invoking duality and thus using the voltage‐conversion type GICs.
General nonlinear equation for LMCR oscillators and its nearly sinusoidal solutions
Authors: Sidorowicz R. S.
Published: June 2007

A generalized feedback oscillator consisting of an ideal nonlinear amplifier and a linear, passive or active LMCR network is considered. The network is of second order and has a ‘biquadratic’ voltage transfer function.

Though such a system represents a large family of important oscillators, it appears that an explicit nonlinear differential equation for it is not known. Consequently, a general nonlinear differential equation, valid for all possible second‐order oscillators is derived. This contains explicitly all the network and amplifier parameters. The van der Pol equation is shown to be a special case of the general equation and to represent the simplest second‐order oscillator. Transient and steady‐state solutions of the general equation are obtained for the case of nearly sinusoidal oscillations. The solutions provide explicit expressions for the transient rise time, steady‐state amplitude, harmonic content and the frequency instability of the oscillator output waveform. The expressions can be used to analyse and evaluate all possible types of second‐order oscillators. A figure of merit for the oscillator network is defined, and the conditions to be met by the amplifier and the network in order to produce oscillations are determined. Validity of the formulas is verified experimentally by means of two representative oscillators.
Order of complexity of rlc networks containing a reactive gyrator
Authors: Milić Mirko M.
Published: June 2007

Using a particular expansion of the network determinant, a simple formula is derived giving the total number of natural frequencies of a passive RLC network containing a reactive gyrator. The order of complexity is expressed in terms of the degrees of the polynomials in the gyration impedance and the alteration in the network topology due to gyrator embedding. Quantitative conditions for the order of complexity of the active network exceeding that of the network without the gyrator are obtained. Formulas are also derived for the number of zero and non‐zero natural frequencies.
Differential sensitivity after large changes in network elements
Authors: Sud D.
Published: June 2007

This paper presents a method for the calculation of first‐ and higher‐order differential sensitivities of the response of a linear reciprocal or non‐reciprocal network following large changes to one or more elements. The method requires only one nodal matrix inversion per frequency. The same inverted matrix can be used when different elements are chosen for large change, providing the original changed element(s) is returned to its nominal value.
Some aspects of band‐pass filter design pertaining to amplifier imperfections and mass production
Authors: Zeheb Ezra
Published: June 2007

A multiple feedback single amplifier realization of a second order band‐pass filter is considered, with certain assumptions made on the amplifier imperfections. The required component values are derived explicitly in terms of the desired filter parameters, the amplifier's open loop finite gain and a degree‐of‐freedom.

The feasible range of the degree‐of‐freedom is derived. It is then used to either minimize variations of filter parameters due to changes in passive and active components (assuming properties pertaining to hybrid technology components), or minimize the variance of the filter parameters relative variations, in order that all mass produced filter sections of the same type will be similar to each other.

For the first case, some useful observations are made concerning the behaviour of the filter under environmental changes, and the allocation of gain to various sections of a cascade filter. Experimental results are reported and compared to anticipated ones.
Piecewise linear approximation of nonlinear oscillators
Authors: Iñigo Rafael M.
Published: June 2007

Differential equations to represent electronic amplifier oscillators have been developed by van der Pol and Scott using a cubic and an arctangent approximation for the amplifier transfer characteristic, respectively. Using a piecewise linear approximation for the transfer characteristic results in more accurate solutions, independently of the amplitude of the oscillations and does not require to determine the coefficients for the approximations, usually a difficult problem.
A new approach to the network modelling of capacitive irises and steps in waveguide
Authors: Rozzi T. E.
Published: June 2007

Classical network representations of waveguide discontinuities assume monomode operation and involve elements which depend not only upon geometry, but also on frequency.

Later approaches to the problem consist of numerical techniques. These are unsuitable for synthesis since they do not yield equivalent networks and involve repeating the field analysis at each frequency, which is cumbersome for applications to wideband design.

A recent approach permits to derive wideband equivalent networks with elements which depend only upon geometry. In this contribution capacitive irises, steps and combinations are treated. These discontinuities occur in filters, transformers, etc. where higher‐order mode interaction cannot be neglected for closely spaced discontinuities. Whatever this spacing may be, higher order mode interaction always occurs in oversize guide. Higher order mode interaction fits naturally into the network modelling presented here. The resulting network representations are either in canonical Foster form of the first type or easily reducible to it. This approach is based on a Rayleigh–Ritz variational solution of the field problem and involves manipulations with small matrices only.

The accuracy of the method is demonstrated for a number of basic configurations, while its flexibility is illustrated by providing simpler equivalent networks, applicable when extreme accuracy is not required. The elements involved are given in graphical or in simple analytical form.
Optimization of the dynamic range and the noise distance of RC‐active filters by dynamic programming
Authors: Lueder E.
Published: June 2007

RC‐active filters are usually realized by cascading 2nd order stages. The degrees‐of‐freedom in this procedure are: the pole‐zero assignments to form the second order transfer functions, the gain‐factors for the stages and the sequence in the cascade. These freedoms will simultaneously be used to maximize the dynamic range and the noise distance of the filters. The exact solution to the problem will be obtained by dynamic programming. A rule of thumb avoiding a computer program and an example are given.
On the unique solvability of RLCT‐networks
Authors: Fischer Hans Dieter
Published: June 2007

In this paper a handy criterion is presented which is necessary and sufficient to check the unique solvability of an RLCT‐network.
State digital filters
Authors: Gensel Joachim
Published: June 2007

A new concept for the construction of digital filters is presented. It is based on so‐called state filters recently suggested by the author. The new filter is compared with Fettweis' wave digital filters. Its multiplier coefficients need about 2 bits more, but it saves at least one multiplier and a considerable number of summers.
Solving piecewise‐linear equations for resistive networks
Authors: Chien M. J. , Kuh E. S.
Published: June 2007

Nonlinear resistive networks can be characterized by the equation f(x)= y where f(x) is a continuous piecewise‐linear mapping of Rn into itself. The n‐dimensional Euclidean space is divided into a finite number of regions, and, in each region say region Rm, we can express f by J(m)x + w(m) where J(m) is a constant n × n Jacobian matrix and w(m) is a constant n‐vector. In this paper we obtain the following results:

If all the Jacobian determinants in the unbounded regions have the same sign, the equation f(x)= y has at least one solution and an algorithm is developed, which obtains one or more solutions in a finite number of steps. The work represents a generalization of early work by Fujisawa, Kuh and Ohtsuki and relaxes the condition imposed on the function. For example, in the bounded regions, the Jacobian matrices can be singular and the sign of Jacobian determinants can be arbitrary.
A new canonic realization of lossless immittance functions using six‐element sections
Authors: Ramachandran V. , Swamy M. N. S.
Published: June 2007

A new canonic realization cycle for lossless driving point immittance functions is given. This is achieved by extracting a six‐element section (involving three inductors and three capacitors), which is terminated in a simpler immittance function whose form is the same but of order six lower than that of the original. This method is easily extended to RC and RL cases.
On a class of nonlinear networks
Authors: Matsumoto T.
Published: June 2007

Some of the properties of a class of nonlinear networks are discussed. The class of networks under consideration is allowed to have very general branch characteristics including couplings among elements of different kinds and discontinuities in time. Firstly, local existence and uniqueness of solutions to the state equations are discussed. Secondly, several global properties of the class of networks are discussed. Some of the properties of the degree of a function and a differential property of implicit function theorem turn out to be useful.
General interpretation of sensitivity functions
Authors: Solymosi J. , Trón T.
Published: June 2007

A general interpretation of sensitivity functions of linear networks is given in order to determine any nth order sensitivity function with respect to any parameter. The calculation uses an indirect method: ‘transfer function products’ give the desired sensitivities instead of derivation. The interpretation makes it possible to construct a computer program, too, which needs only one matrix inversion for a complete sensitivity analysis (including first‐ and higher‐order sensitivities). It is shown that the adjoint network approach is superfluous and more complicated than the given method.
The generalized tree for state variables in linear active networks
Authors: Mark Shew‐Kin , Swamy M. N. S.
Published: June 2007

A tree for the association of state variables in linear active networks is presented. This tree is selected in such a manner that the voltages across the capacitors contained in it and the currents through the inductors contained in its cotree may be chosen as state variables of a linear network. An algorithm for finding such a tree is given, and the association of state variables with this tree are demonstrated by examples.
Equal ripple tolerance characteristics
Authors: Neirynck Jacques , Milić Ljiljana
Published: June 2007

The concept of equal ripple tolerance is introduced and justified in the particular case of the polynomial low pass filter. By comparison with the classical Chebyshev characteristic, it is shown that it is possible to improve the tolerance to element variations by a factor 2. The ultraspherical polynomial provides a closed form specification which is significantly better than the Chebyshev characteristic.
Contribution to the theory of weakly nonlinear oscillators: Part I. An estimation of amplitude and frequency
Authors: Kudrewicz J.
Published: June 2007

Steady state signal in an oscillator is described by a nonlinear integral equation. A new theorem on the existence of an isolated number ω, for which the equation has a periodic eigensolution of period 2π/ω is given in the paper. An approximate value ω and approximate eigensolution can be easily obtained by the describing function method. The main result of the paper is the presentation of an effective estimation of the error of this approximation for weakly nonlinear oscillators.
A quasi‐steady‐state approach to the generation of non‐sinusoidal orthogonal waveforms at microwave frequencies
Authors: Jackson J. Russell , Rhodes J. David
Published: June 2007

By the application of a quasi‐steady‐state time‐domain analysis approach some advance is made in the generation of non‐sinusoidal orthogonal waveforms at microwave frequencies. The main study concerns the time‐domain response of short‐circuited cascades of commensurate transmission lines. It is found that with simple prescribed pole location for the driving‐point impedance. Z11(z), on the unit circle in the z‐plane, a quasi‐steady‐state response is obtained, having a known periodicity. Furthermore, this response is automatically a member of an orthogonal set of waveforms which is uniquely associated with every choice of periodicity.
Component tolerance assignment using the pseudo‐inverse sensitivity matrix
Authors: Adby P. R.
Published: June 2007

A solution to the problem of component tolerance assignment using the pseudo‐inverse sensitivity matrix offers a significant reduction in computational effort compared to other methods by avoidance of random sampling.
Dimensioning the low‐pass filters in pcm terminal equipment
Authors: Schultze Ernst
Published: June 2007

In many PCM terminal equipments both the transmission (signal sampling) and reception (interpolation of the sampled values) sides each employ a circuit in which a low‐pass filter is directly connected to a switch. In the circuits described here the energy transmission takes place during the very short interval where the switch is closed. However, the transmission is not effected by the familiar resonance transfer but by an aperiodic compensation, which is more suitable for practical use. Because of the very short time where the switch is closed as compared with the switching interval, the analysis can be greatly simplified by the use of Dirac pulses. As a result very simple formulas for the frequency characteristics are obtained which can be applied to optimize the circuit elements.
A switching‐parameter algorithm for finding multiple solutions of nonlinear resistive circuits
Authors: Chua L. O. , Ushida A.
Published: June 2007

An efficient algorithm for finding multiple solutions of a system of nonlinear algebraic equations is presented. This algorithm consists of solving an associated system of first order nonlinear differential equations whose independent variable may be switched from one variable to another during each integration step. The choice of the forward Euler predictor and Newton‐Raphson corrector for integrating the differential equations leads to an extremely efficient method for implementing this switching‐parameter algorithm. This approach involves only the recursive solution of an associated system of linear algebraic equations and can be easily programmed. The switching‐parameter algorithm can also be used to derive the driving‐point or transfer characteristic curve of multivalued resistive nonlinear networks.
A note on the computation of large‐change multiparameter sensitivities
Authors: Krishnan R. , Downs T.
Published: June 2007

In this article a method of computing multiparameter finite change sensitivities is derived. The method is conceptually simpler than existing techniques and, for certain applications, computationally more efficient.
Sensitivity evaluation and comparison for high‐order active filters
Authors: Mackay Robert , Sedra Adel S.
Published: June 2007

This paper presents a systematic procedure for evaluating the sensitivity of the transfer function magnitude, and hence the transmission deviation in decibels, for high‐order active filters. The procedure applies for filters having any arbitrary structure of coupled biquadratic sections. The method is illustrated by carrying out a comparative analysis on a bandpass filter realized by the Cascade, Leap‐Frog and Primary Resonator Block approaches.
RC ladder realizations with equal‐valued capacitors
Authors: Ali Adel , Kim H. K.
Published: June 2007

The synthesis of RC low‐pass ladder networks with equal‐valued capacitors is studied. By using congruence transformation, a systematic method is advanced to generate an equivalent two‐port in which as many capacitor values as possible are equalized.
An active biquadratic circuit based on the two integrator loop
Authors: Fidler J. K.
Published: June 2007

The two amplifier version of the two integrator loop which has been recently reported in the literature is shown to be a special case of a more general configuration which exhibits a biquadratic transfer function. Examples of further particular realizations obtained from the general circuit are given.
New theorems in the synthesis of passive multiplexers
Authors: Youla D. C. , Winter F.
Published: July 2007

Coupling networks that divide the frequency spectrum into separate frequency bands and also provide desired filtering are known as multiplexers. In this paper we present four new theorems concerning the synthesis‐theoretic structure of lumped passive multiplexers constructed as lossless reciprocal n‐ports. In particular we prove in Theorem 1 that any set of n – 1 admissible power gains, complementary or otherwise, can be realized by a series interconnection of n–1 appropriately chosen non‐Foster positive‐real functions. In Theorems 2–4 we establish various necessary and sufficient conditions for the realization of bounded‐real gains s21(p),…, sn1(p) given both in magnitude and phase. These conditions reveal that the general problem is one of Nevalinna‐Pick interpolation. Lastly, five worked examples are used to illustrate all facets of the theory.
Letter to the editor design of low‐sensitivity quarter‐plane recursive 2d digital filters
Authors: Palacherla Sridhar R. , Reddy P. S. , Swamy M. N. S.
Published: July 2007

A new technique is given for designing two‐dimensional quarter‐plane recursive digital filters. These filters have low sensitivity in the passband. an implementation scheme using complex multipliers is also given for these filters.
Membrain: A cellular neural network model based on a vibrating membrane
Authors: Henseler J. , Braspenning P. J.
Published: July 2007

This paper introduces the Membrain model describing a neural network architecture which is similar to the architecture underlying the class of cellular neural networks (CNNs). the main difference pertains to the characteristic processing equation, which is based on a wave equation instead of a heat equation. Within the CNN framework, a cellular Membrain model may be obtained by replacing the neuron output function by a first‐order state equation. Furthermore, the network‐cloning templates are chosen such that the CNN behaves like a system of coupled harmonical oscillators. Since the energy of such a system is bounded, the piecewise linear neuron characteristic function may be chosen such that it always operates in the linear regime. Our starting point is the analytical and general solution for forced vibrations with damping. This solution applies to a Membrain neural network whose functional architecture is based on the specialized solution for a network of coupled harmonic oscillators. In particular, we present a Membrain CNN (MCNN) having a toroidal connection structure such that the natural modes of vibration of the net are translation‐invariant. Moreover, depending on the point group of the network, some rotation invariance can also be obtained. Identifying the input of such a network with the initial state of the oscillators gives rise to an output which is in essence a transversally travelling wave made up of components which are coupled harmonic neuronal oscillators; that is, the wave is a superposition of natural modes of vibration of the network. the temporal wave pattern may be transformed into a one‐dimensional temporal signal which is invariant under translation of the initial deflection pattern of the MCNN. the amplitudes of the components in the temporal signal correspond to the power spectrum of the natural vibration modes in the MCNN. Interpreting the initial deflection pattern as a grey‐level image, the temporal signal can be viewed as a modulation of a translation‐invariant ‘fingerprint’ of the image. the signal may be sampled such that the modulated ‘fingerprint’ can be classified using some of the traditional neural network models. In particular we show that (1) a self‐organizing feature map clusters correlated images and (2) a back‐propagation neural network extracts position‐invariant features.
Approximate solutions to a dynamic worst‐case tolerance analysis problem
Authors: Kolev L. V.
Published: July 2007

A dynamic tolerance problem for linear circuits is considered. More specifically, the worst‐case analysis of the scalar step response under interval variations of the circuit parameters is treated. Approximate solutions to the dynamic tolerance analysis problem considered are suggested, two of them having the property of enclosing the exact solution of the problem.

A method for determining the approximate solutions introduced is proposed. It is based on the known integral relationship between the time response and the real part of the frequency response for linear circuits on one hand and certain basic ideas and techniques from interval analysis on the other.

The method reduces to evaluating some interval extension or the range of certain sums or integrals of the real part of the circuit frequency response with respect to the parameter variations.
On the design of 2D IIR digital filters using penalty optimization techniques
Authors: Papamarkos N.
Published: July 2007

In this paper an efficient technique is developed for the design of two‐dimensional recursive digital filters in the frequency domain. the formulation of the design problem is based upon a rational approximation method in parallel with a suitable interior penalty technique. the structure of the proposed approach permits one to include in the design optimization problem additional constraints related to the stability, linear phase and symmetries properties of the resultant filter. In contrast with previous design methods, the coefficients of the filters are determined directly and it is not required to apply any ‘inverse’ or stabilization technique. Analytical examples illustrate the features and effectiveness of the proposed approach.
Double and triple charge pumps with mos diodes: Dynamic models to an optimized design
Authors: Di Cataldo G. , Palumbo G.
Published: July 2007

In this paper the dynamic models of the double and triple charge pumps are extended to circuits in which the diodes are realized with an MOS transistor having a drain‐gate contact. In this circuit realization we must take into account the influence of the source‐substrate voltage on the threshold voltage Vt.

The effects of the source‐substrate voltage on the dynamic behaviour are analysed and discussed in detail. Moreover, simple equations allowing one to perform a pencil‐and‐paper area‐efficient optimized design are developed from the two new models.

The models obtained are also validated by SPICE simulation of the circuit assuming a typical CMOS 3 μm process.
Three loci on mouse chromosome 5 and 10 modulate sex determination in XX Ods/+ mice
Authors: Poirier Christophe , Moran Jennifer L. , Kovanci Ertug , Petit Deborah C. , Beier David R. , Bishop Colin E.
Published: July 2007

In mouse, XY embryos are committed to the male sex determination pathway after the transient expression of the Y‐linked Sry gene in the Sertoli cell lineage between 10.5 and 12.5 dpc. In the C57BL/6J strain, male sex determination program can be modulated by some autosomal genes. The C57BL/6J alleles at these autosomal loci can antagonize male sex determination in combination with specific Sry alleles. In this report, the authors have identified an effect of these C57BL/6J specific alleles in combination with a mutated Sox9 allele, Sox9Ods. Authors report the mapping of three of these genetic loci on mouse chromosome 5 and 10 in a backcross of the Ods mutation to the C57BL/6J background. Our study confirms the importance of the strain C57BL/6J for the investigation of the genetic mechanisms that control sex determination. genesis 45:452–455, 2007. Published 2007 Wiley‐Liss, Inc.
Relations of bulimic symptom frequency and intensity to psychosocial impairment and health care utilization: Results from a community‐recruited sample
Authors: Spoor Sonja T.P. , Stice Eric , Burton Emily , Bohon Cara
Published: July 2007

Objective:

To determine the frequency and intensity of bulimic symptoms related to psychosocial impairment and health care utilization.

Method:

Females (N = 1231, M age = 17.7, range 13–55) from four community‐recruited samples varying in bulimic pathology completed the eating disorder examination, social adjustment scale, and health survey utilization scale.

Results:

Co‐occurrence of binge eating and compensatory behaviors and solely compensatory behaviors ≥1 time/month were associated with elevations in psychosocial impairment. Co‐occurrence of both binge eating and compensatory behaviors and solely compensatory behaviors ≥8 times/month were related to greater service utilization. Solely binge eating and duration of bulimic behaviors were unrelated to these functional outcomes. Overvaluation of body shape and weight showed significant linear relations to the functional outcomes.

Conclusion:

Results suggest that current diagnostic thresholds for bulimia nervosa may be too high when considering functional impairment and service utilization and that different cut‐points need to be considered for different bulimic symptoms. © 2007 by Wiley Periodicals, Inc. Int J Eat Disord 2007
Evaluation of enantioselective binding of antihistamines to human serum albumin by ACE
Authors: Martínez‐Gómez María Amparo , Villanueva‐Camañas Rosa M. , Sagrado Salvador , Medina‐Hernández María José
Published: July 2007

The drug binding to plasma and tissue proteins is a fundamental factor in determining the overall pharmacological activity of a drug. HSA, together with α1‐acid glycoprotein, are the most important plasma proteins, which act as drug carriers, with implications on the pharmacokinetic of drugs. Among plasma proteins, HSA possesses the highest enantioselectivity. In this paper, a new methodology for the study of enantiodifferentiation of chiral drugs with HSA is developed and applied to evaluate the possible enantioselective binding of four antihistamines: brompheniramine, chlorpheniramine, hydroxyzine and orphenadrine to HSA. This study includes the determination of affinity constants of drug enantiomers to HSA and the evaluation of the binding sites of antihistamines on the HSA molecule. The developed methodology includes the ultrafiltration of samples containing HSA and racemic antihistaminic drugs and the analysis of the free or bound drug fraction using the affinity EKC‐partial filling technique and HSA as chiral selector. The results shown in this paper represent the first evidence of the enantioselective binding of antihistamines to HSA, the major plasmatic protein.
Experiments on the hydrometallurgical treatment of copper slimes
Authors: Schoeller W. R.
Published: June 2007

Many attempts have been made to find offective methods of dealing with slimes, the formation of which is one of the problems of oro dressing. Whilst in te United States, I undertook laboratory experiments on the recovery of copper from slimee by a hydrometallurgical process, Chiefly with a view to working them up at the same rate as they are produced at the concentrating plant. The material experimented upon was obtained from the dressing plant of one of the large western smeiters, and contained: Total copper, 2.85 per cent,; soluble copper, 0.32 per cent.; sulphide copper(by difference) 2.53 per cent. Atmospheric oxidation had practically no effect, the quantity of soluble copper being unchanged after 3 months. The rate of solution in water was found to be 0.10 per cent. per 3 months, some what less than at Rio Tinto. The behaviour of the material was tested towards solutions of ferric sulphate and cupric chloride, the solvents proposed in the Siemens und Halsko and the Hoepfner processes.
The composition of Australian (N.S.W.) milk
Authors: Ramsay A. A.
Published: June 2007

The avernge composition of the milk from a heard of over 60 cows at the Hawkesbury Agricultural College is given in the following table, the analyses having been commenced in February, 1911. and continued every week until the end of January, 1912.
The fractional distillation of mixed pine woods
Authors: Peterson J. H. , Forrester R. E.
Published: June 2007

Large quantities of wood, mostly pine wood, have to be got rid of every year in our skipwords. The following experiments were undertaken witb a view to determining whether it would to possible to oarboniso the wood and recover the by‐products in such a manner an to make the process a commerical success.

The exprimental plant consisted of a cylindrical iron retort six feet long by 14 inches in diameter, mounted in brick setting and hanted by hot air supplied in such as manner that the temperature inside the retort could be kept stationary at any point between 100°C. and 400°C for a Considerable length of time. The retort. holding about 4 owt of mixed pine wood, was connected with there condensors and rorubber in which to wash the escaping gears with the tar from a previous operation. In all the testa performed with this apparatus the temperature was raised from about 120°C. to 200°C. over a period of from 10 to 15 hours, and the distellate collected separately. The temperature was then raised to 400°C and the distillate passed into the series of conderusers mentioned above.
Development of the chorioallantoic placenta in Octodon degus—a model for growth processes in caviomorph rodents?
Authors: Mess Andrea
Published: July 2007

The degu Octodon degus is one of the very few members of caviomorph or hystricognath Rodentia that possesses a simply arranged chorioallantoic placenta without advanced lobulation. Therefore this species was used as a model to study regional development and growth processes of the placenta, based on the examination of 20 individuals by light and electron microscopy as well as by using markers for proliferation, trophoblast and endometrial stroma. The results were interpreted by comparison with other hystricognaths in the light of their evolutionary history. It was found that trophoblast derived from the trophospongium is essential for extension of the placenta including the labyrinth: extensive proliferation is restricted to trophoblast cells at the outer margin of the placenta and along internally directed, finger‐tip like protrusions of fetal mesenchyme towards the labyrinth. This kind of placental development is regarded as part of the stem species pattern of hystricognaths, evolved more than 40 million years ago. It is indicated for the first time that the replenishment of the syncytiotrophoblast is similar to corresponding processes in the human placenta. In conclusion, the degu is a useful model for placental growth dynamics, particularly because of its simply arranged placental architecture, and may also serve as an animal model in comparison to human pregnancies. J. Exp. Zool. (Mol. Dev. Evol.) 308B:371–383, 2007. © 2007 Wiley‐Liss, Inc.
Some biological characteristics of transferred free flaps
Authors: Kozarski Jefta V.
Published: June 2007

At the Clinic for plastic surgery and burns of the MMA, we examined 33 patients with transferred 5 cutaneous, 18 miocutaneous, and 10 osteocutaneous free flaps out of which 10 were done on foot, 13 on the lower leg, and 10 on the face. We analyzed the blood circulation (patency of arterial microanastomosis and perfusion) of transferred free flaps, recovery of sensitivity, functioning of the sebaceous and sweat glands as well as histomorphologic changes in the skin of the transferred free flaps during the period of 6 up to 36 months after the free flap transfer and compared with the same characteristics of the skin and tissue of the surrounding area of the recipient region. © 2007 Wiley‐Liss, Inc. Microsurgery, 2007.
Video‐assisted versus conventional microsurgical training: A comparative study in the rat model
Authors: Blidisel Alexandru , Jiga Lucian , Nistor Alexandru , Dornean Vlad , Hoinoiu Bogdan , Ionac Mihai
Published: June 2007

Recent technical development has led to remarkable performances in video‐guided surgical procedures. A video‐endoscopic system (VES) is evaluated as an alternative magnifying solution for microsurgical procedures and compared to table‐top microscopes in terms of technical and surgical aspects. Six surgical residents without microsurgical experience, alternating both systems, performed each 12 aortic end‐to‐end anastomoses on Sprague‐Dawley rats using the triangulation technique. All anastomoses underwent quality review, total and single suture time, suture spacing, vessel bite, vessel overlapping and wall penetration were evaluated and graded. Overall anastomosis quality score was 52.28 (out of a maximum of 140) using the microscope and 42.7 using the VES. Despite significant differences in total anastomosis time, the learning curves are similar for the two systems and no major differences were noted in terms of overall anastomosis quality. Video‐assisted microsurgery can become a useful instrument for microsurgery training. © 2007 Wiley‐Liss, Inc. Microsurgery, 2007.
Planning the Care of Unemployables
Authors: Shipman George A.
Published: June 2007

The care of unemployables needs orderly financing and permanent adiministrative mechanics.
Cities and Their Debt Burdens
Authors: Bird Frederick L.
Published: June 2007

Balancing of budgets,determination of borrowing margin,to planning of debt structure,and wise sepending necessary to place communities on a sound financial basis.
Relocating the Isolated Settler
Authors: Rowlands W. A.
Published: June 2007

Governmental economy end improved citizenship and morale may be expected from the wise use of Drelocation program.
To Sweeten Our Tax Tea
Authors: Buttenheim Harold S.
Published: June 2007

An outline of Suggested SOUrces ofmunicipal revenue to provide maximum public benefits with minimum private burden .
Competent citizenship: The only way to good government
Authors: Womer P. P.
Published: June 2007

There is great need for an intelligent, determined, and nationwide effort to improve the quality of citizen thinking and citizen action.
Social insurance abroad and at home: The background of social security legislation
Authors: Armstrong Barbara Nachtrieb
Published: June 2007

The social security program follows the experience of other industrial countries of the world in adopting social insurance.
The social security act: An appraisal
Authors: Rubinow I. M.
Published: June 2007

While comprehensive and containing much that might not have been expected, it omits many things which should be included in a social insurance act.
The essentials of unemployment compensation
Authors: Witte Edwin E.
Published: June 2007

Compensatin for involuntary unemployment, to be paid for a limited time, and only to the extent of a part of the wage loss, the basis of all unemployment insurance laws.
Federal‐state program of unemployment compensation
Authors: Cohen Wilbur J.
Published: June 2007

Summary of the federal social security act and the ten state laws which make it effective.
Public employment offices and unemployment compensation
Authors: Connor Franklin G.
Published: June 2007

Well organized and efficiently administered system of public employment exchanges necessary to a successful functioning of national program of unemployment insurance.
Old‐age assistance
Authors: Stevenson Marietta
Published: June 2007

The conditions imposed upon the states to received federal aid for old‐age assistance follow the trends in state legislation.
Financing the welfare provisions of the social security program
Authors: Blough J. Roy
Published: June 2007

The social security program recognizes the need for federal aid for welfare activities with state and local administration.
Louisiana after long
Authors: Carr Frederick W.
Published: June 2007

Will the legislature about to convene retain the dictatorial legislation placed on the statute books by the “Kingfish”?.
The federal municipal debt adjustment act
Authors: Hillhouse A. M.
Published: June 2007

Experience under the act too meager for definite conclusions to be drawn as to its usefulness.
Fiscal aspects of serial bonds
Authors: Studenski Paul
Published: June 2007

Proper distribution of bond maturities on important aspect of the debt problem.
The decline, fall and resurrection of the credit of the city of detroit
Authors: Hart Henry
Published: June 2007

Despite a huge debt load, a long depression, and closed banks, all of which proved too great a strain on its financial stability, Detroit has pulled itself out of the mire of default to a place where its bonds are again in demand as investments.
The bonded debt of 283 cities as at January 1, 1936
Authors: Rightor C. E.
Published: June 2007

Substantial reduction in debt load made by majority of cities throughout the country during past year.
Federal‐municipal relations—the road thus far
Authors: Reinhold Frances L.
Published: June 2007

A descriptin of the means by which the nation has come to the aid of its cities during the depression years.
By‐products of police radio
Authors: Erdman Charles R.
Published: June 2007

Will use of the radio by polilce departments lead to a much disired consolidation of public safety departments.
Planning and cooperation among international organizations
Authors: Brownlow Louis
Published: June 2007

A sound foundation has been laid for effetive cooperation between international agencies interested in the better administration of local governemnts.
The international union of local authorities
Authors: Vinck Emile
Published: June 2007

Thirty national organizations of municipal officials have joined international group.
The changing state‐local financial picture in France
Authors: Sharp Walter R.
Published: June 2007

National government contributed nearly a quarter of local expenditures during 1934 in centrally collected taxes, grants‐in‐aid, loans, etc.
The Italian law on communal and provincial government
Authors: Steiner H. Arthur
Published: June 2007

A description of the act governing local authorities under Fascist rule.
The proposed New York city charter
Authors: Tanzer Laurence Arnold
Published: June 2007

Revised charter will be submitted to popular referendum on November 3.
Shall we save the township?
Authors: Bromage Arthur W.
Published: June 2007

Measuring its cost against value received, shall we sav the money spent in township operation?
Governmental research and the citizen
Authors: Evans S. Howard
Published: June 2007

A plan for public co‐operation in applying results of research.
The municipal power of investigation
Authors: Olmsted Sophia A.
Published: June 2007

A survey of city charters shows that the powers of the department of investigation and accounts of the City of New York are almost unique.
Homestead exemption for Nebraska?
Authors: Gordon A. W.
Published: June 2007

Recent survey forcasts great loss of revenue not easily replaced by other forms of taxtaiton if homestead exemption adopted.
Police organization and administration
Authors: Wilson O. W.
Published: June 2007

Wichita's police director lists requisites for efficient police department.
The future of the municipal research bureau
Authors: Fishack Howard G.
Published: June 2007

There has probably been no time in our history when a greater need existed for citizen understanding of government then at present.
The business man's stake in the civil service
Authors: Johnson Robert L.
Published: June 2007

Demise of the spoils system will come only after strong public demand for extension of the merit system to federal, state and local governmnt empolyees.
A new program for unemployment relief
Authors: Kahn Dorothy C.
Published: June 2007

Adequate employment statistics, employment services, long range planning, and retraining among essentials of future relief plans.