bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simulation of the charge transport in DNA
Authors: Yamanaka T. , Dutta M. , Stroscio M. A. 
Published: November 2007

AbstractIn this research, charge transport characteristics in a double‐stranded DNA are discussed. Based on the polaron drift model, DNA was characterized by a 1D quantum wire model and the phonon scattering rates were calculated by deformation potential theory. Furthermore, using the calculated pho‐ non scattering rates, the carrier dynamics in DNA were characterized by the Monte Carlo simulation technique. The simulation result shows a rapid charge transport from the initial point. The validity of our modeling is also discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Carrier density dependence of nonresonant carrier tunneling in GaAs double quantum wells – effect of exciton and free carrier thermodynamic
Authors: Lu S. L. , Ushiyama T. , Tackeuchi A. , Muto S. 
Published: November 2007

AbstractNonresonant carrier tunneling dynamics in GaAs/AlGaAs double quantum wells as a function of carrier density was investigated by using time‐resolved pump and probe measurements. At low temperatures, tunneling time increases with increasing carrier density. At high temperatures, no dependence of tunneling time on carrier density was shown. This unique behavior is well explained by the thermodynamic effect be‐ tween excitons and free carriers as a function of carrier density on the tunneling process. At low temperatures, a larger fraction of excitons at a higher carrier density, which have a relatively slow tunneling time in contrast to free electrons, leads to a slow tunneling time. The independence of the tunneling time at high temperatures is attributed to the insensitivity of the exciton population to the increased carrier density. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multiple Linear Regression Analysis and Optimal Descriptors: Predicting the Cholesteryl Ester Transfer Protein Inhibition Activity
Authors: Rasulev Bakhtiyor F. , Toropov Andrey A. , Hamme Ashton T. , Leszczynski Jerzy 
Published: November 2007

AbstractQuantitative structure–activity relationships have been developed for a set of 40 halogenated substituted N‐benzyl‐N‐phenyl aminoalcohol compounds. IC50 values for Cholesteryl Ester Transfer Protein (CETP) inhibition activity for these compounds expressed in log units have been modeled by Multiple Linear Regression Analysis (MLRA) based on descriptors generated by DRAGON software and optimal descriptors approach. Forty benzene derivatives have been divided into training (n=20) and test (n=20) sets. In the case of the MLRA, the three‐variable model has the best predictive potential. Comparison of the quality of MLRA and optimal descriptor models shows that the predictive potential of the one‐variable model, based on the optimal descriptor, provides a low correlation coefficient in the training set. However, this one‐variable model performs better for the test set when compared to the two‐ and three‐variable MLRA models.
Pronounced Effect of DNA Hybridization on Click Reaction Efficiency
Authors: Wirges Christian T. , Gramlich Philipp M. E. , Gutsmiedl Katrin , Gierlich Johannes , Burley Glenn A. , Carell Thomas 
Published: November 2007

AbstractWe report about the efficiency of the click reaction directly on PCR products containing alkyne‐modified uridine nucleosides. Galactose azide was clicked onto single‐stranded and double‐stranded 300mer DNA in order to investigate the efficiency of sugar labeling of DNA under various conditions. Single‐stranded alkyne‐modified DNA was prepared by selective lambda exonuclease digestion of 5′‐phosphate‐labeled double strands. A comparison of the click reaction efficiency on modified single and double stranded 300mers under identical conditions shows a pronounced effect of the strandedness on the yield of the click reaction.
Peptoids on Steroids: Precise Multivalent Estradiol–Peptidomimetic Conjugates Generated via Azide–Alkyne [3+2] Cycloaddition Reactions
Authors: Holub Justin M. , Garabedian Michael J. , Kirshenbaum Kent 
Published: November 2007

AbstractWe have developed a family of functionalized peptidomimetic oligomers for the multivalent display of bioactive ligands in a site‐directed manner. Sequence‐specific N‐substituted glycine peptoid oligomer scaffolds were synthesized on solid phase to include up to six azidoalkyl sidechains. These constructs were used as substrates for Cu(I)‐catalyzed azide–alkyne [3+2] cycloaddition reactions. 17α‐ethynylestradiol was conjugated at up to six positions along the peptoid backbone, generating estradiol–peptidomimetic conjugates in good yield. We evaluate how the binding avidities of these compounds to the estrogen receptor are enhanced when the valency of hormone ligand presentation is increased.
Click Chemistry‐Led Advances in High Content Functional Proteomics
Authors: Salisbury Cleo M. , Cravatt Benjamin F. 
Published: November 2007

AbstractThe availability of complete genome sequences for numerous eukaryotic and prokaryotic organisms has inspired the advent of new methods to functionally characterize proteins on a global scale. Chemical approaches, in particular, have emerged as a powerful way to investigate the proteome, providing small‐molecule probes that report on protein activity and Post‐Translational Modification (PTM) state directly in complex biological samples. Many of the key advances made in chemical proteomics can be attributed to the development of efficient bio‐orthogonal reactions such as the copper (I)‐catalyzed Huisgen's azide–alkyne cycloaddition, a reaction commonly known as “Click Chemistry” (CC). The generation of “clickable” proteomics probes has removed the requirement for bulky reporter tags, thereby allowing access to more biologically relevant systems such as live cells or animals. The versatility of CC has also allowed for greater experimental efficiency, as different reporter tags (i.e., a fluorophore for detection or biotin for enrichment) can be appended to a single probe. Such advances have enabled researchers to identify protein activities dysregulated in disease states, assess the selectivity of enzyme inhibitors in vivo, and inventory specific PTMs on a proteome‐wide scale.
Characterization of glutathione conjugates of chloroacetanilide pesticides using ultra‐performance liquid chromatography/quadrupole time‐of‐flight mass spectrometry and liquid chromatography/ion trap mass spectrometry
Authors: Pérez Sandra , Farkas Michael , Barceló Damià , Aga Diana S. 
Published: November 2007

AbstractGlutathione S‐transferases (GSTs) isolated from maize were used to catalyze the conjugation of glutathione (GSH) with chloroacetanilide herbicides, producing stable conjugates that were structurally characterized using ultra‐performance liquid chromatography/quadrupole time‐of‐flight mass spectrometry (UPLC/QqToF‐MS) and liquid chromatography/ion trap mass spectrometry (LC/IT‐MS). Enzyme‐mediated dechlorination of alachlor, metolachlor, and propachlor resulted during GSH conjugation as revealed by the mass spectra of the conjugates, which was confirmed by the loss of the chlorine isotopic signature and from high accurate mass measurements. Several fragmentation patterns in the mass spectra of the chloroacetanilide‐GSH conjugates can be used to verify the identities of the enzyme reaction products, such as characteristic ions corresponding to the neutral loss of glutamic acid residue (129 Da) and water (18 Da) observed in the product ion spectrum. For the first time, data are presented showing detection of chloroacetanilides that are conjugated with two GSH molecules, in addition to the known single GSH conjugates. Copyright © 2007 John Wiley & Sons, Ltd.
Data flow language DFC: Design and implementation
Authors: Shimada Toshio , Sekiguchi Satoshi , Hiraki Kei 
Published: November 2007

AbstractThis paper presents the basic idea in the design of the data‐flow language DFC and problems and their solutions in its implementation on the data‐flow computer SIGMA‐1. DFC is a data‐flow language designed with consideration of the compatibility to C language. In the first part of the paper, a design to integrate the functional properties while maintaining the compatibility to C language is shown for the conditional and loop sentences, which are the major components of DFC, as well as the data structure. Then the conversion procedure from DFC to the code of SIGMA‐1 is described together with the problems and their solutions.Especially, the generation of a graph is discussed in detail, which enables the resource reclamation in execution with the data‐flow computer SIGMA‐1.
Association‐based parser for speech understanding systems—framework design on cognitive exploration
Authors: Hori Masahiro , Mizoguchi Riichiro , Kawachi Masaaki , Uehara Kuniaki , Toyoda Jun'Ichi , Kakusho Osamu 
Published: November 2007

AbstractIt is well known that the use of the high‐level information data such as language information is indispensable in the speech understanding system. Because the human speech understanding process is executed unconsciously, sufficient knowledge is not yet available concerning what kind of high‐level information data are utilized and in what ways. We made two kinds of studies from the viewpoint of cognitive science to acquire knowledge about the use of high‐level information. Based on the result of study, an association based parser ASP was realized for the speech understanding system. ASP receives a large number of phrase candidate sequences as the input, and identifies the correct phrase sequence by examining successively the available syntactic, semantic and associative information. Especially, the topic is extracted first from the input candidates as a whole, and an association mechanism is employed where the vocabulary associated from the topic is processed with priority, being considered as an active word. The study in this paper is described from the viewpoint of cognitive science, and the framework of the language processing system obtained from the study is presented.
Membership problem for head languages and multiple context‐free languages
Authors: Kasami Tadao , Seki Hiroyuki , Fujii Mamoru 
Published: November 2007

AbstractThis paper considers multiple context‐free grammars (mcfg's) which inherit the basic properties of context‐free grammars with generative capacity stronger than that of context‐free grammars but weaker than that of context‐sensitive grammars. It is shown that the time complexity of the membership problem for languages generated by mcfg's is polynomial. It is shown also that head grammars introduced by Pollard for describing the syntax of natural language correspond to a special subclass of mcfg's and, as a corollary, the time complexity of the membership problem for languages generated by head grammars is of order n6.* This is an improvement by one order of magnitude, compared with the result by Pollard.
Bi‐directional current‐mode basic circuits for the multilevel signed‐digit arithmetic and their evaluation
Authors: Kameyama Michitaka , Kawahito Shoji , Higuchi Tatsuo 
Published: November 2007

AbstractFor highly parallel operation, use of a radix‐4 signed‐digit (SD) number system is attractive. Since the SD number system uses more than three values in each digit, multivalued coding is suitable for the implementation of the high‐speed compact arithmetic integrated circuits. We have already proposed the basic idea of multivalued bidirectional current‐mode circuits which are essentially suitable for the SD arithmetic implementation. This paper describes the experimental results of the basic SD arithmetic integrated circuits by means of the bidirectional current‐mode circuits and their evaluation. A parallel SD adder is implemented with 2‐μm CMOS technology and the addition time is estimated to be about 10 ns. The addition time of the SD adder is 14 times faster than that of the conventional ripple‐carry adder and is three times faster than that of the block carry lookahead adder.
A high‐speed rotation method for binary images based on coordinate operation of run data
Authors: Shima Yoshihiro , Kashioka Seiji , Higashino Jun'Ichi 
Published: November 2007

AbstractThe rotation of an image is one of the fundamental functions in image processing and is applied to document image processing in the office or for industrial use with industrial robots. A method of image rotation based on digital image data has been developed. This paper assumes the binary digital data, and proposes a method which is different from the traditional one based on pixel data. This method can execute a high‐speed rotation of the binary image based on coordinate data for the start and the end of the run. Using the proposed method, the image rotation at an arbitrary angle can be realized by the real number operation on the run data, which is suited to the general‐purpose processor. It is a practically useful method since the processing is fast and less memory capacity is required. In this paper, a discussion is made first on the format of the run data, the number of runs and the data complexity for the binary data. Then the newly devised rotation for the binary image is described. The rotation method is used to perform successively the skew coordinate transformations in the vertical and horizontal directions, to determine the rotated image. Finally, a document image is actually rotated on a large‐scale computer. The processing time was examined to demonstrate experimentally the usefulness of the proposed method.
Efficient distributed algorithms solving problems about the connectivity of network
Authors: Park Jungho , Tokura Nobuki , Masuzawa Toshimitsu , Hagihara Ken'Ichi 
Published: November 2007

AbstractThis paper presents efficient distributed algorithms on an asynchronous network for the following problems: finding bi‐connected components, finding cutpoints, finding bridges, testing for bi‐connectedness and finding strongly connected components of a directed graph defined on a network. All these distributed algorithms use a depth‐first search tree having an arbitrary processor in the network as its root. The communication complexity of these algorithms is O(nlogn+e) and their ideal‐time complexity is O(nG(n)), where n and e represent the numbers of processors and links, respectively, and G(n) is almost a constant. It is shown also that a lower bound for the communication complexity of the five problems is O(e) and a lower bound for their ideal‐time complexity is O(n).
Performance analysis of multiprocessor systems with bus architecture
Authors: Matsunaga Toshio , Fukumura Yoshimi 
Published: November 2007

AbstractThe performance of bus‐architecture multiprocessor systems is discussed in this paper. The goal is to clarify the effective organizations of future computer systems by analyzing the total system performance of tightly coupled multiprocessors (TCMP) and loosely coupled multiprocessors (LCMP). For the purpose of comparing TCMP and LCMP designs, queueing models for hardware processing and software processing are introduced and system performance is evaluated. As a result, limitations on the TCMP model and the conditions under which it is more profitable than the LCMP model are shown. Further, the influence of multimedia communication on system performance is indicated.
A parallel processing architecture for image understanding
Authors: Watanabe Masaki , Ohta Yuichi , Ikeda Katsuo 
Published: November 2007

AbstractGeneral‐purpose image understanding requires that an image understanding system be built that will accommodate multiple image understanding algorithms and thereby provide the system with flexibility and robustness. This paper proposes a mechanism whereby multiple modules can cooperate with each other and process in parallel, each of which modules is designed to execute a dedicated image understanding algorithm.An architecture to implement the mechanism onto a parallel computer is also presented. Knowledge regarding the execution of an algorithm and the results obtained by the execution are stored in each separate module. These results are accessed when the modules communicate with each other. Intra‐module parallel processing can be done by executing in parallel processes that are dynamically generated with query by query coming to each module to reply. This intra‐module processing makes it possible to concurrently apply the same algorithm to different local parts of a single image.A stereo matching system, one application of the mechanism, is introduced and some experimental results obtained on a parallel computer are shown.
Efficient facsimile data reduction by thinning process
Authors: Mizuno Shoji 
Published: November 2007

AbstractPicture preprocessing and encoding methods that can greatly reduce the facsimile picture signal information are presented here. Preprocessing consists of smoothing and thinning lines before encoding in a transmitter. Lines are thickened by postprocessing after decoding in a receiver. Because the post‐processed picture quality is lower than that for the original picture, it is important to prove whether entropy reduction by thinning is still great. To do so requires considering picture quality degradation caused by preprocessing. Proof of high entropy reduction involves a comparison of the entropy for a preprocessed picture with that for a reduced‐size picture. The picture quality of the latter when enlarged back to its original size is comparable with that for the post‐processed picture. This comparison reveals that entropy reduction by preprocessing is 5 percent for printed Japanese and 19 to 24 percent for handwritten English and Japanese, as well as for typewritten English.An encoding scheme called predictive MH coding, which takes advantage of the feature wherein line width in a preprocessed picture is almost a single picture element, is applied to encode preprocessed pictures. As already predicted by entropy measurement, it was found that the compression ratio for the proposed method is 1.04 times as high as that for the CCITT‐standard MR coding for printed Japanese. Furthermore, it is from 1.3 to 1.4 times as high as that for the CCITT‐standard MR coding for handwritten English and Japanese, as well as for typewritten English.
Construction and evaluation of the identity transformers for cryptographic key distribution
Authors: Matsumoto Tsutomu , Takashima Youichi , Iraai Hideki 
Published: November 2007

AbstractThis paper describes the key predistribution system (KPS) which simplifies the use of public key cryptography in a large‐scale complex network. The identity (ID) transformer R, which is needed in the realization of KPS by a linear scheme, is proposed and evaluated; R is an algorithm which transforms a short vector into a long vector. It is desired that R be executed in a simple way by an IC card and can realize a one‐way and random injective function; a method to realize such R is discussed fully in this paper. An example R1 with the specified parameters is realized using 8 bit CPU, and it is verified that the ID transformer algorithm can be executed in approximately 0.4 s, using the one‐way algorithm with the processing speed of approximately 50 kbit/s. As a result of evaluation of the statistical randomness, it is verified that the random condition is satisfied.
A condition matching algorithm for high‐cost rules in production systems: Effectiveness measurements
Authors: Kimura Haruhiko , Kobayashi Shin‐Ya , Sumiyoshi Kazuyuki , Takebe Tsuyoshi 
Published: November 2007

AbstractProduction systems are well known as the most essential tools for developing expert systems. The most important problem to solve in a production system is that of speeding up its condition matching process. A production system quite often requires excessive matching time. This excessive computational time is normally caused by so‐called high‐cost rules that require a great deal of computational time. The objective of this paper is to develop an algorithm that can reduce the condition matching times of these high‐cost rules.An algorithm is presented here that can efficiently handle the high‐cost rules by reducing the worst case computational time for condition matching compared with the conventional Rete or Treat algorithms. An experiment was performed to demonstrate the effectiveness of the proposed algorithm high‐cost rules.
Computer graphic model of walking quadruped animal
Authors: Mizuno Hironori , Muraoka Yoichi 
Published: November 2007

AbstractNo animation method has ben established which makes flexible and pliant the walk of an animal keeping a balance of its body parts with joints. This paper proposes a computer graphic model of a quadruped animal (e.g., a dog) which walks and runs naturally and autonomously. The model is based on: (1) calculation of shift of the position of the animal over frames using “speed function”; (2) balancing the motions of four legs and the vertebra with their joints. The speed is obtained from analyses of actual animal motions. A smooth natural action of the animal over frames is achieved by allocating the speed function to spatial shifts of the body and its joints. To obtain a real time operation, “kinematic control” is used, ensuring smooth motions as in a “dynamic control.” Motions of an animal body in an image are controlled by specifying the path and speed of the body. The effect of the proposed model has been evaluated successfully by experiments.
Behavioral and biochemical responses to d‐amphetamine in MCH1 receptor knockout mice
Authors: Smith Daniel G. , Qi Hongshi , Svenningsson Per , Wade Mark , Davis Richard J. , Gehlert Donald R. , Nomikos George G. 
Published: November 2007

AbstractThe melanin‐concentrating hormone (MCH) system is anatomically and functionally interlaced with the mesocorticolimbic dopamine system. Therefore, we investigated whether MCH1 receptor knockout (KO) mice are more susceptible than wild‐type (WT) mice to psychostimulant‐induced locomotor stimulation and sensitization, dopamine receptor‐mediated phosphorylation events and c‐fos expression within the frontal cortex and ventral striatum. MCH1 receptor KO mice have 20% higher basal locomotor activity, are hypersensitive to the locomotor activating effects of d‐amphetamine (1 mg/kg), and develop behavioral sensitization to a regimen of repeated d‐amphetamine administration that does not induce sensitization in WT mice. In addition, d‐amphetamine‐mediated regulation of p44‐mitogen activated protein kinase (MAPK) phosphorylation within the frontal cortex was significantly enhanced in MCH1 receptor KO mice, when compared with WT mice. No significant genotype difference in the effects of d‐amphetamine on MAPK phosphorylation events within the ventral striatum, phosphorylation at Ser897 of the NR1 subunit of the NMDA receptor or Ca2+ and cyclic AMP response‐element binding‐protein (CREB) at Ser133 in the frontal cortex was detected. d‐Amphetamine (3 mg/kg) increased c‐fos expression within the frontal cortex in MCH1 receptor KO mice, but not WT mice. There were no d‐amphetamine‐induced changes in c‐fos expression within the ventromedial striatum in KO or WT mice. Overall, MCH1 receptor KO mice are hypersensitive to the behavioral and molecular effects of the dopaminergic psychostimulant d‐amphetamine. Increased frontal cortical MAPK phosphorylation and c‐fos expression in MCH1 receptor KO mice indicates that the MCH1 receptor may be an important target for treating neuropsychiatric disorders characterized by frontal cortex dysfunction, including depression, attention deficit hyperactivity disorder (ADHD) and schizophrenia. Synapse 62:128–136, 2008. © 2007 Wiley‐Liss, Inc.