bluuebunny/crossref_metadata_2025 huggingface dataset:
Proposal of chaotic steepest descent method for neural networks and analysis of their dynamics
Authors: Tani Jun
Published: July 2007

Most of the neural network models based on the Lyapunov stability contain various problems such as the trap of the local minimum, and the limit of their dynamic performances has been pointed out.

This paper attempts to provide a new dynamic performance to such a neural network model by introducing chaos dynamics. The features of the chaotic dynamic model proposed here is that the dynamical equation describing the trajectory on the energy curve has a periodically varying nonlinear resistance in the dissipation term. By iterating the stable and unstable phases, the chaotic transitions of the state can be realized.

The proposed dynamic model is applied to the error backpropagation learning and the memory recall in the Hopfield‐type network, and the chaotic minimum transitions in the dynamic process are verified, it is verified further that the intermittent chaos generated by an appropriate parameter manipulation can introduce useful dynamic behaviors into the network, e.g., the flexible learning and the memory recall with a structure containing both stability and plasticity.
Convergence properties of numerical simulation for neural networks
Authors: Urahama Kiichi
Published: July 2007

This paper discusses the convergence of the numerical solution of the neural network, whose stability is such that any trajectory asymptotically approaches the equilibrium solution. It is shown first that when the connection among neurons is weak, the upper limit of the step width, for which the asynchronous iteration converges, is the same as in the synchronous iteration. It is pointed out that the asynchronous method is expected to achieve a faster convergence in the parallel computer. On the other hand, when the synaptic connection is symmetrical, the asynchronous iteration does not converge in general unless the step width is set smaller than that of the synchronous iteration.

It is shown also that the stiffness of the Hopfield network to solve the combinational optimization problem is enhanced with the increase of the network scale. Since the computational complexity is expected to increase rapidly in the forward Euler method, the iterative method based on the backward Euler method is proposed. It is shown that the proposed method has a better convergence property.

Finally, the foregoing theoretical results are verified qualitatively through simple examples.
Neural network using oscillators
Authors: Endo Tetsuro , Takeyama Kazuhiro
Published: July 2007

This paper proposes an oscillator neural network which replaces the sigmoidal nonlinearities in a Hopfield neural network with oscillators. When oscillators are used as saturating nonlinearities and their rise and fall times are utilized, results similar to simulated annealing are obtained, and therefore the desired solution can be obtained in a relatively short time. As examples, we show that the 4‐bit A/D converter problem, the 10‐city traveling salesman problem, and a simple associative memory problem can be solved by the oscillator neural network.
Circuit module placement method to minimize manhattan wire length
Authors: Kasai Masahiro , Yamada Shoichiro
Published: July 2007

In the automatic layout design of LSI, the placement method based on Newton's method is known to produce relatively satisfactory results as the minimization of the wiring length for the module. However, a problem in this placement method is that the evaluation function must be differentiated and the total wiring length including the absolute‐value function cannot be used directly as the evaluation function. Because of this problem, the square‐sum of the wiring lengths has been used as the evaluation function instead of the sum of the wiring lengths.

This paper examines first the optimal solution for the small‐scale placement problem and points out that the sum of the wiring lengths should be used as the object of minimization. Then the absolute‐value function contained in the expression for the sum of wiring lengths is approximated by the differentiable function, and a method is proposed which directly minimizes the total wiring length by Newton's method. Finally, the proposed method is applied to various placement problems and the results are presented, thus verifying the usefulness of the method.
Spectral estimation method of a multistage nonstationary process and its application
Authors: Takizawa Yumi
Published: July 2007

This paper considers the time series observed through the nonstationary processes and proposes the multistage instantaneous maximum entropy method aiming at the inverse estimation of the behavior of the original process on the spectrum. The performance of the method is demonstrated and examples of useful applications are presented. To achieve the goal, the cascaded multistage AR process is considered as the model for the process from the excitation source of the time series to the observation. The excitation source is assumed as a simple white Gaussian noise.

The response of the process is represented by a time‐varying lattice filter. The instantaneous value of the power spectrum is determined from the prediction error estimation function defined at a point on the time axis (instantaneous maximum entropy method, IMEM). Then the nonstationarity (time‐varying property) of the process is noted, and the separation of the connected processes is discussed. For this purpose, the nonstationary frequency axis of the two‐dimensional spectrum is considered based on IMEM.

A filter to separate the considered process from others is designed. This filter passes the time‐varying component of the considered process but eliminates the time‐varying components due to the interference from other processes, based on thea prioriinformation concerning the time‐varying properties of the considered process.

Finally, this paper presents the results of evaluation for the test using the artificial signal as well as the results of evaluation for two application examples. Comparing the result to that of the traditional method, the novelty and the usefulness of the proposed method are demonstrated. The system features are that the accumulation of the error in the multistage prediction can efficiently be suppressed using IMEM with the excellent prediction performance, which results in the high follow‐up ability to the time‐varying process, and the excellent spectrum estimation.
How intractable is the modified chosen discrete logarithm assumption?
Authors: Itoh Toshiya , Hosokawa Tomomi
Published: July 2007

In modern cryptologic theory, the design of cryptographic protocols is often based on the assumed difficulty of number theoretic problems. Especially, in order to prove the security of a cryptographic protocol based upon the assumed difficulty of a problem, a very important role is played by the legitimacy (as concerns the security of the cryptographic protocol) of that cryptographic assumption. Recently, Kurosawa, Ogata, and Tsujii proposed a new cryptographic assumption, the Chosen Discrete Logarithm Assumption (CDLA), and showed that any language in NP has a four‐move, zero‐knowledge interactive proof (ZKIP) under the CDLA.

In this paper, we define the modified CDLA and consider its legitimacy. Our principal result (that the modified CDLA is not a legitimate cryptographic assumption) follows from a theoretical analysis of expected polynomial‐time algorithms and the concrete construction of an algorithm based on the Artin conjecture.
Highly sensitive ultrasonic flow velocity measuring method with FM component elimination
Authors: Tanisawa Shigeru , Hirose Haruo , Fukuzawa Hiroshi
Published: July 2007

We reported an FM ultrasonic velocimeter in which the frequency was varied by means of a ramp generator in order to reduce the number of multiple path signals. The generator requires good linearity and a necessity to change frequency with suitable speed, sometimes quite high. The authors experimentally confirm some standing wave suppressing effect using sinusoidal FM. For improvement of sensitivity, we used a second FM signal for computational processing in such a way that a new received signal with FM components eliminated was produced by adding both the received and the second FM signals. Flow velocity was thus derived from the phase between the new received and carrier signals. In elimination processing, the influence of the flow velocity and temperature change of fluid was compensated by a fixed command control system for residual FM components in a new received signal. From experiments, we were able to confirm the following:

The system is effective in elimination of FM components.

The measured phase shift is proportional to flow velocity and temperature change of fluid.

The sensitivity for flow velocity was improved considerably.

The control voltage of the fixed command control system was found usable for measurement of flow velocity, and a compensation method on the temperature change of fluid was introduced into this system.
Student modeling and its diagnosis based on synthesis of sets of production rules
Authors: Okamoto Toshio
Published: July 2007

This paper presents a method to model a student's understanding structure in an intelligent teaching system (ITS), especially the diagnosis of the comprehensive bug rule set. As the modeling of the student, the bug used in the problem‐solving process is identified by combining the primitive bug rules and the bug generation process of the student is represented by the production rules. Then a structural model for the bug generation is proposed based on a number of problem‐solving processes.

The structure of bug generation is described from the viewpoints of redundancy, leap thinking, and ordering. As an actual example, the solution of the second‐order equation by factorization in elementary mathematics is considered. The construction of the intelligent CAI is discussed, including the proposed modeling technique. A highly practical system structure is presented which includes the teaching knowledge to make the student understand and master the operational skill of the world, although simple.
Synthesis of flow networks minimizing the sum of edge capacities
Authors: Kishimoto Wataru , Takeuchi Masashi , Kishi Genya
Published: July 2007

Several synthesis methods to construct a flow network with the minimum sum of edge capacities for a given terminal capacity matrix have already been presented. However, there are networks that cannot be constructed by the known method.

For the case where the given terminal capacity matrix is called elementary terminal capacity matrix, a synthesis method is presented that can construct any undirected flow network with the minimum sum of edge capacities. This paper is based on that synthesis method and presents a synthesis method that can construct any undirected flow network with the minimum sum of edge capacities for a given terminal capacity matrix with that matrix as the terminal capacity matrix.
Control limit analysis for the sidelobe reduction of ultrasonic transducer arrays
Authors: Kamata Hiroshi , Chubachi Noriyoshi
Published: July 2007

The effects of random response errors in amplitude and phase, element failures, and crosstalks on array gain and sidelobe level of ultrasonic transducer arrays are investigated by multivariate statistical analysis. The derived estimate equations are confirmed by simulation and measured data of various sonar arrays. The results show that the reasonable control limit of response errors for an infallible sidelobe reduction is not determined by the mean value of statistical sidelobes described in other papers but by the 95‐percent control line proposed in this paper.
Interpolated digital sinusoidal oscillators
Authors: Watanabe Eiji , Nakajima Nobuyasu , Saito Tetsuro
Published: July 2007

The digital sinusoidal oscillator considered in this paper is one of the signal sources employed in the digital signal processing system. A construction of the oscillator is discussed where the memory capacity is reduced and the increasing rate of the noise is suppressed by interpolating the output of the oscillator of table look‐up type or feedback type.

A design method for the interpolation filter is presented first where no interpolation error is produced if the coefficient wordlength of the interpolation filter is infinite. Then, considering the case where the wordlength is kept finite, the hold‐type sampling expander is proposed where the waveform distortion is kept low compared with the traditional zero‐interpolation‐type sampling rate expander. The distortion in the proposed method is analyzed where the wordlength of the interpolation filter coefficient is kept finite, and the waveform distortion is shown to be low. The increasing rate of the round‐off error is examined by a computer simulation for the oscillator, which is obtained by applying the interpolation to the feedback‐type oscillator. The effectiveness of the interpolation is demonstrated.

Finally, a construction of the block‐digital sinusoidal oscillator is shown with a smaller hardware complexity than in the traditional method, by constructing the block‐structured oscillator by realizing the proposed interpolation filter as a polyphase filter.
Spectral estimation of speech by mel‐generalized cepstral analysis
Authors: Tokuda Keiichi , Kobayashi Takao , Imai Satoshi , Chiba Takeshi
Published: July 2007

This paper proposes a spectral estimation method of speech based on mel‐generalized cepstral representation. The spectral estimation based on generalized cepstral representation is a method that unifies the cepstral method and the linear prediction method. By this method, the spectral model can be varied continuously from the all‐pole model to the exponential model.

This paper also discusses the following: the method of spectral estimation, where the mel‐generalized cepstrum is used instead of the generalized cepstrum; the uniqueness of the solution for the minimization problem; the solution method; and the convergence of the solution. The proposed method has the same features as those of the method based on the generalized cepstrum where the spectral model can be varied continuously and the stability of the obtained transfer function is guaranteed. Another feature is that characteristics similar to the human auditory sensation, i.e., the high resolution in the low‐frequency range and the coarse resolution in the high‐frequency range, are obtained since the mel‐generalized cepstrum is used as the parameter, which is the generalized cepstrum defined on the mel‐frequency axis. Finally, the features and the effectiveness of the proposed method is demonstrated by analysis examples of the synthesized signals and natural speech.
Multiterminal source coding with linked encoders
Authors: Oohama Yasutada
Published: July 2007

Slepian and Wolf considered a coding system (called SW system) for coding the multiterminal (information) source. This paper extends the SW system and defines anew a system (called SWL system) where encoders are mutually links. The problem of determining the optimal error exponent in the admissible rate region has not been answered completely for the SW system.

It is shown in this paper that this problem can completely be solved for the SWL system. It is shown also that the optimal exponent can be achieved by the universal code. It is shown further that even if the encoders are linked, the admissible rate region is not enlarged and the reliability of the information transmission is not improved when the transmission rate is outside the admissible rate region. It is interesting to note that those results correspond in a sense to those for the channel with feedback.
Precision analysis of wiener kernels measured by cross‐correlation method
Authors: Yokota Yasunari , Toda Naohiro , Usui Shiro
Published: July 2007

One representation of the nonlinear dynamical system is the expansion by the functional series. Especially, the functional series expansion by Wiener has the feature that the kernel can be estimated relatively easily by inputting normal white noise. Consequently, it is used widely in the analysis of the neural system and other problems. However, few studies have been made on the quantitative evaluation of the accuracy of the kernel estimation because of its difficulty.

This paper proposes a practical method of evaluating the accuracy of kernel estimation, thereby simplifying the problem by introducing appropriate restrictions and approximations into the kernel estimation. By this approach, the accuracy of kernel estimation can be represented as a function of the Volterra kernel of the system, the input power level, and the data length. The result is verified by a numerical experiment.

It is shown that there exists the optimal input power level in the identification of the nonlinear system that maximizes the accuracy of kernel estimation. This is a new finding which has not been observed in the theory of the linear system.
A parallel algorithm fork‐way graph partitioning
Authors: Isomoto Kazunori , Wakabayashi Shin'Ichi , Yoshida Noriyoshi , Miyao Jun‐Ichi
Published: July 2007

With the recent development of semiconductor integration technology, the amount of data that must be handled in the layout design of VLSI is increasing rapidly. Even if the improvement of the processing speed of the computer in the future is considered, it is desired to develop a high‐speed layout algorithm compared to the conventional method.

This paper discusses thek(> 2)‐way graph partitioning problem, which is one of the most basic problems concerning the layout design. A parallel algorithm is proposed. The general method to solve this problem has been to apply hierarchically the two‐way graph partitioning algorithm. In this method, the algorithm can easily be executed in parallel by operating a number of processors at each hierarchy. A problem then is the efficiency of the processor and the computation time.

This paper considers thek‐way graph partitioning and proposes a new method called nonhierarchicalk‐way graph partitioning, aiming at the education of the computation time by parallel processing. In general, it is considered difficult to improve the speed sufficiently by the parallel processing, while maintaining the same accuracy of the solution as that of the sequential algorithm. In this paper, the effectiveness of the proposed algorithm is shown by a simulation experiment on the sequential computer.
A bayesian approach to an optimal ARQ number in data transmission
Authors: Sandoh Hiroaki , Nakagawa Toshio , Koike Shin‐Ichi
Published: July 2007

The automatic repeat request (ARQ) system is one of the means to achieve a high reliability in the data transmission system. In this system the data are retransmitted for a certain number of times when an error is produced due to the disconnection, noise, or distortion in the data communication channel; thus, the correct transmission is achieved.

However, when a correct transmission cannot be achieved due to the incorrect data format or a fault of the channel, it is necessary that the retransmission be terminated as soon as possible, examine the data format or channel state, or switch the channel to another. In such a case, the behavior of the system depends greatly on the upper‐limit set for the number of repeat requests. At the present state, however, the upper limit for the number of repeat requests is determined empirically with little theoretical basis.

This paper introduces the subjective probability from the viewpoint of the Bayesian theory for the probability that the data transmission is made physically impossible due to the fault of the channel or other factors. To set a reasonable value for the number of repeat requests, the expected cost for the data transmission is formulated and the optimal number of repeat requests to minimize the cost is investigated. By numerical examples, the features of the proposed method are discussed.
Theoretical analysis of nonlinear effects in surface acoustic waves on waveguide
Authors: Nakagawa Yasuhiko , Takanose Tsuyosi
Published: July 2007

A structure with a ribbon‐shaped metal thin film on a highly coupled anisotropic piezoelectric substrate acts to concentrate the acoustic wave energy into the region with the thin film. A device making use of the nonlinear interaction of the surface acoustic waves propagating in opposite directions on this Δ v/v waveguide is the surface acoustic wave convolver. However, a theoretical analysis on its efficiency is not sufficient.

In the present research, the guided wave characteristics of this Δ v/v waveguide are derived accurately so that the nonlinear components generated on the waveguide are computed. The generation efficiency of the surface acoustic wave at the second harmonic generated from this mechanism in the direction orthogonal to the waveguide is analyzed theoretically. The conversion efficiency of the split waveguide‐type convolver proposed previously by the authors can be derived quantitatively so that the evaluation of the surface acoustic wave nonlinear device becomes possible.
Test generation for sequential circuits based on boolean function manipulation
Authors: Choi Hoyong , Kohara Takashi , Ishiura Nagisa , Shirakawa Isao , Motohara Akira
Published: July 2007

In this paper, a test generation algorithm STAR for sequential circuits based on Boolean function manipulation is presented. Based on the product machine traversal (PMT) method, which generates test patterns using breadth‐first search of state‐pairs and an implicit state enumeration method of a product machine of fault‐free and faulty machines, STAR algorithm attempts to improve the computational efficiency by introducing a mixture of breadth‐first/depth‐first traversal based on the sequential depth, improvement on the image computation, and the computation of fault‐difference functions by the symbolic single‐fault propagation method. The results of the experiments on ISCAS 89 benchmark circuits show threefold improvement on the computational time over the simple PMT method.
The adhesion receptor CD155 determines the magnitude of humoral immune responses against orally ingested antigens
Authors: Maier Michael K. , Seth Sebastian , Czeloth Niklas , Qiu Quan , Ravens Inga , Kremmer Elisabeth , Ebel Maria , Müller Werner , Pabst Oliver , Förster Reinhold , Bernhardt Günter
Published: July 2007

CD155, originally known as the cellular receptor for poliovirus, is the founding member of a subfamily of immunoglobulin‐like adhesion receptors. Apart from its function in establishing adherens junctions between contacting epithelial cells, the engagement of CD155 with two recently identified ligands, CD226 and CD96, mediates immunologically relevant processes such as NK cell‐driven killing of tumor cells in humans. Here we report on the generation and immunological analysis of mice constitutively deficient of CD155. Moreover, the expression profile of CD155 on hematopoietic cells has been determined using newly established antibodies. CD155‐deficient mice develop normally without displaying an overt phenotype. However, the animals are distinguished by distinct deficits in the development of a regular humoral immune response. Whereas systemic challenges revealed no differences, orally administered antigen evoked less efficient IgG and IgA antibody responses despite of normal IgM titers when compared to wild‐type mice. Therefore, CD155 may assist in an efficient humoral immune response generated within the intestinal immune system.
Synthesis of a 3‐Arylisoquinoline Alkaloid, Decumbenine B
Authors: Wada Yasuhiro , Nishida Naoto , Kurono Nobuhito , Ohkuma Takashi , Orito Kazuhiko
Published: July 2007

The synthesis of a 3‐arylisoquinoline alkaloid, decumbenine B, was accomplished in a reaction sequence based on the formation of an indolizine ring {dibenz[a,f]indolizin‐5(7H)‐one} followed by its cleavage at the amide bond, starting with an interaction of 5,6‐(methylenedioxy)isoquinoline with 2‐bromo‐5,6‐(methylenedioxy)benzoyl chloride in the presence of Bu3SnH.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Synthesis of 4‐Amino Derivatives of 5‐Oxoproline
Authors: Krasnov Victor P. , Vigorov Alexey Yu. , Nizova Irina A. , Matveeva Tatyana V. , Grishakov Alexander N. , Bazhov Iliya V. , Tumashov Andrey A. , Ezhikova Marina A. , Kodess Mikhail I.
Published: July 2007

The possibility of obtaining the stereoisomeric derivatives of 5‐oxoproline and glutamic acid with a tertiary amino group at C‐4, using the nucleophilic substitution of bromine in dimethyl (2S,4RS)‐4‐bromo‐N‐phthaloylglutamate with secondary amines followed by resolution of diastereomers and removal of protecting groups has been studied. We have shown that the reaction with arylamines results in optically pure 5‐oxoproline derivatives in high yields. In the case of more basic amines, the reaction is accompanied by racemization, and the target products can be isolated only as diastereomeric racemates.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
A Theoretical Study of Tricyclo[4.2.1.02,5]non‐2(5)‐ene, Tricyclo[4.2.2.02,5]dec‐2(5)‐ene and Related Pyramidalized Alkenes
Authors: Fernández José A. , Vázquez Santiago
Published: July 2007

HF, MP2 and CAS ab initio theory and B3LYP, B3PW91, SVWN and MPW1PW91 density functional theory were used to study a series of cyclobutenyl‐fused tricycles such astricyclo[4.2.1.02,5]non‐2(5)‐ene, tricyclo[4.2.2.02,5]dec‐2(5)‐ene and related compounds. Examination of the stepwise torsional potentials for 5–8 and 10–11 by scanning of the cyclobutene butterfly angles at the B3LYP/6‐31G(d) level revealed that there is only one minimum for each compound, with the cyclobutene bent in the endo direction in 5, 6, 10 and 11, and in the exo direction in 8. Examination of the stepwise heats of hydrogenation of 9 revealed that this compound, which displays a method‐dependent ground state, is antiaromatic. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Application of Sphere Cap Mercury Microelectrodes and Scanning Electrochemical Microscopy (SECM) for Heavy Metal Monitoring at Solid/Solution Interfaces
Authors: Daniele Salvatore , Ciani Ilenia , Baldo M. Antonietta , Bragato Carlo
Published: July 2007

In this paper, a combination of anodic stripping voltammetry (ASV) at mercury microelectrodes and scanning electrochemical microscopy (SECM) was employed to establish the concentration profiles of heavy metal ions at the soil/water interface of a natural sediment and bauxitic‐soil sample. Air dried soil samples were equilibrated with aqueous solutions containing 0.5 M NaCl plus acetate buffers or HClO4 at different concentrations to allow the achievement of different pH either in the aqueous phase or in the soil slurry. It was verified that mixing acidified aqueous solution and the soil without stirring led to concentration profiles displaying a maximum at the water/soil interface. This was explained as due to pH gradients that originated at the soil/water interface and within the soil slurries. On the other hand, mixing the soils and water solutions, under stirring for 24–48 h, provided almost uniform pH throughout the system. This allowed obtaining uniform metal ion concentrations within the soil slurries. For the evaluation of the concentrations, the anodic charge involved in the stripping step was utilized. The mercury microelectrode was standardized in a 0.5 M NaCl aqueous solution by performing calibration plots over the concentration range 0.1–500 μM. To evaluate the concentrations of the metal ions in the soil slurries, a procedure was developed to obtain the apparent diffusion coefficients of the metal ions, which depended on the physical properties of the soil such as porosity and tortuosity. The microanalytical methodology proposed here can be utilized for predicting the mobilization of trace elements from soils that comes into contact with acid rain.
Influence of Phosphorus Doping Level and Acid Pretreatment on the Voltammetric Behavior of Phosphorus Incorporated Tetrahedral Amorphous Carbon Film Electrodes
Authors: Liu Aiping , Zhu Jiaqi , Han Jiecai , Wu Huaping , Gao Wei
Published: July 2007

Phosphorus incorporated tetrahedral amorphous carbon (ta‐C:P) films are prepared by filtered cathodic vacuum arc technology with phosphine as the dopant. The influence of phosphorus doping level and acid pretreatment on the electrochemical properties of ta‐C:P electrodes is investigated by cyclic voltammetry, Raman spectroscopy and X‐ray photoemission spectroscopy. Results indicate that phosphorus incorporation improves the electrical and electrochemical behaviors of the films. A moderate phosphorus atomic fraction facilitates the interfacial electron transport in context of a high content of effective phosphorus impurities. Furthermore, acid pretreatment activates the surface of the films and gives an excellent reversible feature towards ferricyanide oxidation reaction by removing the inactive oxygenated sites and exposing the active conduction channels.
The effects of the dopamine and serotonin transporter polymorphisms on clinical features and treatment response in geriatric depression: a pilot study
Authors: Lavretsky Helen , Siddarth Prabha , Kumar Anand , Reynolds Charles F.
Published: July 2007

Background

The authors examined the role of dopamine and serotonin transporter genetic polymorphisms in clinical and cognitive features of subjects with late‐life depression, and in preferential treatment response to the combination of methylphenidate and citalopram.

Method

The authors studied fifteen outpatients with major depression in a pilot ten‐week double‐blind trial of methylphenidate combined with citalopram and compared to citalopram and placebo. Response was defined as a score on the Hamilton Depression Rating Scale (24‐item) of less than 10. All underwent genotyping to determine the dopamine (DAT VNTR) and serotonin (5HTTLPR) transporter polymorphisms.

Results

Subjects with DAT VNTR 10/10 genotype had greater cognitive executive dysfunction at baseline compared to others. However, they responded preferentially to methylphenidate added to citalopram with a greater reduction in depression severity over time compared to other subjects.

Conclusions

DAT VNTR 10/10 genotype may be associated with an endophenotype of late‐life depression with executive dysfunction that responds preferentially to methylphenidate added to a selective serotonin reuptake inhibitor, which warrants replication in a large sample. Copyright © 2007 John Wiley & Sons, Ltd.
Can training community mental health nurses to support family carers reduce behavioural problems in dementia? An exploratory pragmatic randomised controlled trial
Authors: Moniz‐Cook Esme , Elston Christine , Gardiner Eric , Agar Sharon , Silver Miriam , Win Thein , Wang Michael
Published: July 2007

Background

Community mental health nurses (CMHNs) are the backbone of specialist mental health services in the UK. This study evaluated the effects of training CMHNs in a systematic psychosocial intervention (PSI), to help family carers manage behavioural changes in their relative with dementia.

Method

One hundred and thirteen family carers received PSI support from a ‘trained’ (experimental), or a ‘usual practice’ (control) CMHN. Primary (day‐to‐day behaviour problems and management) and secondary (carer mood) outcome measures were obtained at baseline, 6, 12 and 18 months. CMHN training and supervision commenced prior to, and continued throughout, the 18‐month study.

Results

Patient cognition declined in both groups, but problem behaviour reduced in experimental group families. However this effect was associated with the practice of some, not all, CMHNs. Carer management and mood improved with PSI support. In contrast, by 18 months, families supported by conventional CMHNs reported reduced coping resources, increased problem behaviour and their level of depression worsened. Only two CMHNs adhered to the PSI‐protocol.

Conclusions

Some, but not all, ‘trained’ CMHNs used the PSI to help family carers reduce behavioural problems. A relatively long but not intensive PSI of 12–18 months was needed to moderate carer mood. Dementia‐specific practice arrangements, training and sustained clinical supervision are important for the delivery of effective psychosocial interventions in dementia. Copyright © 2007 John Wiley & Sons, Ltd.
Early detection of Alzheimer's disease: a new working memory paradigm
Authors: Toepper Max , Beblo Thomas , Thomas Christine , Driessen Martin
Published: July 2007

Objectives

Early detection of Alzheimer's disease (AD) offers the chance to decelerate the patients' cognitive decline and to prolong a self‐determined, independent life. Neuropsychological testing is one key approach to establish an early diagnosis. Whereas more global cognitive abilities can be preserved until further progression of the disease, specific executive abilities such as dual‐task or active inhibition processes decline very early. Our recently developed working memory paradigm, the Block Suppression Test (BST), requires an active inhibition of irrelevant stimuli and thus should differentiate between Alzheimer patients and controls in early disease stages more accurately than classical screening instruments.

Methods

In a pilot study we applied the BST, the MMSE, the clock drawing test, a digit‐word transformation task as well as verbal and spatial memory span tasks to a group of 13 patients with Alzheimer's disease and 13 elderly controls and compared the instruments' capability to differentiate between patients and controls.

Results

The BST showed the highest sensitivity among all applied tests with a perfect differentiation of healthy subjects and patients. The patients' backward spans were significantly reduced, in the inhibition condition they showed disproportionally worse performances.

Conclusions

Our results reveal a specific inhibition deficit in mild AD rather than a global working memory breakdown. The BST thus was superior for early diagnosis. However, these findings must be replicated in a larger sample to prove the BST's applicability for the early diagnostic assessment of AD and other dementias. Copyright © 2007 John Wiley & Sons, Ltd.
New applications of dithiocarbamates in organic synthesis
Authors: Grainger Richard S. , Innocenti Paolo
Published: July 2007

The application of dithiocarbamates in group transfer radical cyclization reactions is described. Carbamoyl diethyldithiocarbamates are synthesized in two high‐yielding steps from secondary amines and act as sources of carbamoyl radicals through chemical or photochemical initiation. Group transfer radical cyclization reactions lead to dithiocarbamate‐functionalized lactams. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:568–571, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20336
Syntheses, structures, and supramolecular properties of giant π‐expanded macrocyclic oligothiophenes
Authors: Iyoda Masahiko
Published: July 2007

Fully conjugated π‐expanded macrocyclic oligothiophenes with 60π‐, 90π‐, 120π‐, 150π‐, and 180π‐electron systems (1–5) were synthesized using modified McMurry coupling reaction as a key step. Compound 1 was converted into macrocyclic oligo(2,5‐thienylene‐ethynylene) 6 using bromination‐dehydrobromination procedure. X‐ray analysis of 1 revealed a unique molecular and packing structure, reflecting a round, planar shape with nanoscale inner cavity. Interestingly, 2 and 3 self‐aggregate in the solid state to form nanowires. The structure of fibrous aggregates was established by scanning electron microscopic and atomic force microscopic analyses. Compounds 1–6 exhibit multi‐step reversible redox behavior with fairly low first oxidation potentials, reflecting their cyclic conjugation. Doping of 1–3 with iodine gives semiconductors owing to their π‐donor properties and π–π stacking ability. © 2007 Wiley Periodicals, Inc. 18:460–466, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20337
Ortho‐thioquinones and mediterranean diet: The sulfur connection
Authors: Menichetti Stefano , Pagliuca Chiara , Viglianisi Caterina
Published: July 2007

The antioxidant activity of several hydroxy‐4‐thiaflavanes was determined either by using the 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) bleaching method or by measuring their ability to inhibit the autooxidation of styrene or cumene. Based on this, the role played by the number and position of hydroxy groups and by the oxidation state of sulfur was rationalized and quantified, providing good indications for optimizing the structural features required to make these “double‐faced” antioxidants perform at their best. The ability of selected 4‐thiaflavanes to protect DNA by oxidative damage in vitro is also discussed. © 2007 Wiley Periodicals, Inc. 18:489–499, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20338
Conformationally induced electrostatic stabilization (CIES) of persulfoxides. A comparison to homologous sulfoxides
Authors: Clennan Edward L. , Hightower Sean E.
Published: July 2007

Computational and experimental evidence that participation of a remote heteroatom occurs during the formation and decomposition of persulfoxides is presented. The experimental ramifications of remote participation includes a dramatic increase in the rate of reaction with singlet oxygen and a decrease in the conformationally dependent ability of sulfides to physically deactivate singlet oxygen. The ability of different heteroatoms to participate is evaluated with a natural bond orbital analysis, and a comparison of the extent of participation in persulfoxides and their homologous sulfoxides is presented. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:591–599, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20343
Ecstasy (MDMA) and memory function: a meta‐analytic update
Authors: Laws Keith R. , Kokkalis Joy
Published: July 2007

A meta‐analysis was conducted to examine the impact of recreational ecstasy use on short‐term memory (STM), long‐term memory (LTM), verbal and visual memory. We located 26 studies containing memory data for ecstasy and non‐ecstasy users from which effect sizes could be derived. The analyses provided measures of STM and LTM in 610 and 439 ecstasy users and revealed moderate‐to‐large effect sizes (Cohen's d) of d = −0.63 and d = −0.87, respectively. The difference between STM versus LTM was non‐significant. The effect size for verbal memory was large (d = −1.00) and significantly larger than the small effect size for visual memory (d = −0.27). Indeed, our analyses indicate that visual memory may be affected more by concurrent cannabis use. Finally, we found that the total lifetime number of ecstasy tablets consumed did not significantly predict memory performance. Copyright © 2007 John Wiley & Sons, Ltd.
Insolvency law: a comparative analysis of the preference tests in the Hong Kong Special Administrative Region (HKSAR) and Australia
Authors: Quo Shirley
Published: July 2007

This paper examines the unfair preference tests under corporate insolvency legislation in the Hong Kong Special Administrative Region (HKSAR) and Australia and undertakes a comparison of the law as it exists in relation to the tests in these jurisdictions. It suggests that the objective effects‐based test used in the Australian provisions may be more effective in terms of challenging unfair preferences than the subjective ‘desire’ test based on the actual or presumed intention of the debtor company used in HKSAR. Copyright © 2007 John Wiley & Sons, Ltd.
Preventive effect of S‐allyl cysteine sulfoxide (alliin) on lysosomal hydrolases and membrane‐bound atpases in isoproterenol‐induced myocardial infarction in wistar rats
Authors: Sangeetha T. , Darlin Quine S.
Published: July 2007

In this study, S‐allyl cysteine sulfoxide (SACS) was used to evaluate its preventive effect in isoproterenol (ISO)‐induced myocardial ischemia in male Wistar rats. Rats were pretreated with SACS (40 and 80 mg kg−1) orally for 5 weeks. After the treatment period, ISO (150 mg kg−1) was administered subcutaneously to rats at an interval of 24 h for 2 days. The activities of β‐D‐N‐acetyl‐glucosaminidase, β‐galactosidase, β‐glucosidase, and acid phosphatase increased in serum and heart in ISO‐induced rats. In addition, these rats showed a significant (p < 0.05) increase in the activities of β‐glucuronidase and cathepsin‐D in serum and heart and a significant (p < 0.05) decrease in their activities in lysosomal fraction of the heart. The activity of Na+K+‐ATPase declined, while those of Ca2+‐ and Mg2+‐ATPases significantly (p < 0.05) elevated in the heart of ISO‐induced rats. Pretreatment with SACS (40 and 80 mg kg−1) showed a significant (p < 0.05) effect in all the biochemical parameters studied. The effect at a dose of 80 mg kg−1 body weight was more effective than that at 40 mg kg−1 body weight and brought back all the biochemical parameters to near normal levels. Hereby, our study shows the membrane‐stabilizing as well as antioxidant effects of SACS in ISO‐induced rats. © 2007 Wiley Periodicals, Inc. J Biochem Mol Toxicol 21:118–124, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20166
Manganese‐induced apoptosis in rat myocytes
Authors: Yang Huijuan , Sun Yiguo , Zheng Xiaoxiang
Published: July 2007

Manganese can be toxic to the heart, causing dysfunction following long exposure. In our experiments, we examined the cytotoxicity of manganese in neonatal rat ventricular myocytes (NRVM) by MTT assays in vitro. Results showed that after incubation in the different concentrations of manganese for 24 h, apparent cytotoxicity was observed. At 500, 1000, and 1500 2 μM of manganese, the percentage of cell viability dropped to 82% ± 6.13, 78% ± 5.28, and 66% ± 4.22, respectively. When cells were treated for 48 h, all concentrations tested exerted toxic effect; especially from 500 to 1500 μM the cell viability dropped from 67% ± 4.84 to 37% ± 3.25. Apoptosis in NRVM was then examined by flow cytometry. Results showed that the percentage of apoptotic cells treated with 500 μM of manganese for 24 h increased from 4% ± 0.84 to 7% ± 1.16. After 48 h of incubation, this percentage increased to 11% ± 0.91. There was no significant difference between control groups (0 μM manganese) after 24 and 48 h incubation. The morphological changes of NRVM nuclei were visualized with the fluorescent DNA‐binding dye Hoechst33342 after incubation in 500 μM of manganese for 48 h. Compared with normal nuclei, apoptotic nuclei showed the typical features of fragmentation and condensation. To investigate whether there are any apoptotic gene expression changes during apoptosis, we examined the expression level of Bcl‐2, Bax, and P53 mRNAs after treatment with 500 μM of manganese for 48 h. The Bcl‐2 mRNA expression decreased while the expression of Bax as well as P53 mRNAs increased. These results suggested that manganese cytotoxicity on NRVM could induce apoptosis in NRVM cells. The apoptosis process might involve, and be promoted by, the changes of the expression levels of P53, Bcl‐2, and Bax proteins. © 2007 Wiley Periodicals, Inc. J Biochem Mol Toxicol 21:94–100, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20172
Thorstein Veblen and Dementia praecox
Authors: Sommer Robert
Published: July 2007

Both of Thorstein Veblen's wives and another woman he loved had nervous breakdowns, while a fourth woman to whom he was emotionally very close committed suicide. Yet when Veblen published an article entitled “Dementia praecox,” he did not mention his personal contact with serious mental disorder. This detachment is consistent with Veblen's approach to writing. Veblen considered himself to be a detached observer who wrote objectively about society rather than subjectively about himself. © 2007 Wiley Periodicals, Inc.
Quantification of superparamagnetic iron oxide (SPIO)‐labeled cells using MRI
Authors: Rad Ali M. , Arbab Ali S. , Iskander A.S.M. , Jiang Quan , Soltanian‐Zadeh Hamid
Published: July 2007

Purpose

To show the feasibility of using magnetic resonance imaging (MRI) to quantify superparamagnetic iron oxide (SPIO)‐labeled cells.

Materials and Methods

Lymphocytes and 9L rat gliosarcoma cells were labeled with ferumoxides‐protamine sulfate complex (FE‐PRO). The cells were labeled efficiently (more than 95%) and the iron concentration inside each cell was measured by spectrophotometry (4.77–30.21 pg). Phantom tubes containing different numbers of labeled or unlabeled cells, as well as different concentrations of FE‐PRO, were made. In addition, labeled and unlabeled cells were injected into fresh and fixed rat brains.

Results

Cellular viability and proliferation of labeled and unlabeled cells were shown to be similar. T2‐weighted images were acquired using 7T and 3T MRI systems, and R2 maps of the tubes containing cells, free FE‐PRO, and brains were made. There was a strong linear correlation between R2 values and labeled cell numbers, but the regression lines were different for the lymphocytes and gliosarcoma cells. Similarly, there was strong correlation between R2 values and free iron. However, free iron had higher R2 values than the labeled cells for the same concentration of iron.

Conclusion

Our data indicate that in vivo quantification of labeled cells can be done by careful consideration of different factors and specific control groups. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
MRI of tumor angiogenesis
Authors: Barrett Tristan , Brechbiel Martin , Bernardo Marcelino , Choyke Peter L.
Published: July 2007

Angiogenesis has long been established as a key element in the pathophysiology of tumor growth and metastasis. Increasingly, new molecularly targeted antiangiogenic drugs are being developed in the fight against cancer. These drugs bring with them a need for an accurate means of diagnosing tumor angiogenesis and monitoring response to treatment. Imaging techniques can offer this in a noninvasive way, while also providing functional information about the tumor. Among the many clinical imaging techniques available, MRI alone can provide relatively good spatial resolution and specificity, without ionizing radiation and with limited side effects. Arterial spin labeling (ASL) and blood oxygenation level‐dependent (BOLD) imaging techniques can be employed to confer indirect measures of angiogenesis, such as blood flow and blood volume, without the need for external contrast agents. Dynamic contrast‐enhanced (DCE)‐MRI is rapidly emerging as a standard method for directly measuring angiogenesis during angiogenesis‐inhibitor drug trials. As macromolecular MR contrast agents become available, they will inevitably be utilized in the assessment of tumor perfusion and vessel permeability. Meanwhile, technological advances have made imaging at a molecular level a possibility. They have brought the potential to directly target MR contrast agents to markers of angiogenesis, such as the αvβ3 integrin. Before this is used clinically, however, substantial gains in sensitivity brought about by improved coils, pulse sequences, and contrast agents will be needed. Herein we discuss the techniques currently available for MRI of angiogenesis, along with their respective advantages and disadvantages, and what the future holds for this evolving field of imaging. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
MRI of the posterolateral corner injury: A concise review
Authors: Pacholke David A. , Helms Clyde A.
Published: July 2007

The posterolateral corner of the knee represents a complicated area of anatomy and function. Failure to recognize injury to the posterolateral structures in the acute setting can result in long‐term disability. Magnetic resonance imaging (MRI) provides a noninvasive evaluation of such structures. A systematic and simplified approach to the MRI evaluation of posterolateral corner injury can aid in diagnosis and subsequent surgical consideration. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.