bluuebunny/crossref_metadata_2025 huggingface dataset:
Somatostatin‐immunoreactive interneurons contribute to lateral inhibitory circuits in the dentate gyrus of control and epileptic rats
Authors: Boyett Jesse M. , Buckmaster Paul S.
Published: November 2004

Lateral inhibition, a feature of neuronal circuitry that enhances signaling specificity, has been demonstrated in the rat dentate gyrus. However, neither the underlying neuronal circuits, nor the ways in which these circuits are altered in temporal lobe epilepsy, are completely understood. This study examines the potential contribution of one class of inhibitory interneurons to lateral inhibitory circuits in the dentate gyrus of both control and epileptic rats. The retrograde tracer wheat germ agglutinin‐apo‐horse radish peroxidase‐gold (WGA‐apo‐HRP‐gold) was injected into the septal dentate gyrus. Neurons double‐labeled for glutamic acid decarboxylase (GAD) and the retrograde tracer are concentrated in the hilus and may contribute to lateral inhibition. Neurons double‐labeled for somatostatin and the retrograde tracer account for at least 28% of GAD‐positive neurons with axon projections appropriate for generating lateral inhibition in control rats. Despite an overall loss of somatostatin‐expressing cells in epileptic animals, the number of somatostatin‐positive interneurons with axon projections appropriate for generating lateral inhibition is similar to that seen in controls. These findings suggest that somatostatinergic interneurons participate in lateral inhibitory circuits in the dentate gyrus of both control and epileptic rats, and that surviving somatostatinergic interneurons might sprout new axon collaterals in epileptic animals. Hippocampus 2001;11:418–422. © 2001 Wiley‐Liss, Inc.
Neuroimaging studies of the hippocampus in schizophrenia
Authors: Heckers Stephan
Published: November 2004

Three neuroimaging techniques, morphometric neuroimaging, magnetic resonance spectroscopy, and functional neuroimaging, have provided evidence for abnormal hippocampal structure and function in schizophrenia. Hippocampal volume reduction is now one of the most consistent structural abnormalities found in schizophrenia: it is present at the onset of the illness and, to a lesser degree, in first‐degree relatives of schizophrenic probands. Decreased levels of N‐acetyl‐aspartate point towards a cellular basis of such volume changes. Functional neuroimaging studies have demonstrated abnormal levels of hippocampal activity at rest, during the experience of auditory hallucinations, and during the performance of memory retrieval tasks. These results of neuroimaging studies complement evidence from post‐mortem and behavioral studies, which have found regionally specific abnormalities of the hippocampus and of memory function in schizophrenia. Hippocampus 2001;11:520–528. © 2001 Wiley‐Liss, Inc.
Probing the human hippocampus using rCBF: Contrasts in schizophrenia
Authors: Medoff Deborah R. , Holcomb Henry H. , Lahti Adrienne C. , Tamminga Carol A.
Published: November 2004

Regional cerebral blood flow (rCBF) data from two PET‐15O water schizophrenia studies were analyzed using individually placed, magnetic resonance (MR)‐guided hippocampal volumes of interest (VOI). In one study, normal (N = 10) and schizophrenic (N = 18) volunteers performed an overlearned auditory discrimination task in rest, control, and decision conditions. In the other study, schizophrenic and normal volunteers received the noncompetitive NMDA receptor antagonist ketamine and placebo and had sequential rCBF evaluations. Moreover, the schizophrenic volunteers were off drug in one study and on antipsychotic drug in the second study, allowing an additional comparison of medication status. VOIs were placed on anterior, middle, and posterior hippocampal areas in each PET image from both studies, redirected from an MR scan, and individually adjusted. While no hippocampal activation was apparent in either the normal or schizophrenic group in the task vs. condition comparison, rCBF was higher in the schizophrenic than in the normal hippocampus in both task and control conditions, independently. In addition, at rest rCBF was significantly higher in the unmedicated group of schizophrenics than in the group of medicated patient volunteers and higher than in the normal comparison group. This suggests that schizophrenia is associated with elevated rCBF in the hippocampus, which “normalizes” with antipsychotic drug treatment. Ketamine, the noncompetitive NMDA receptor antagonist, was more potent in reducing rCBF in the schizophrenic group compared to the normal volunteer group. These data are consistent with a previous report from our laboratory of reduced NMDA receptor NR1 subunit expression and possible abnormal NMDA receptor composition in schizophrenia. These data show an abnormality of hippocampal function in schizophrenia and suggest that this abnormality may be associated with the pathophysiology of the illness. Hippocampus 2001;11:543–550. © 2001 Wiley‐Liss, Inc.
Clonal chromosomal aberrations in simian virus 40‐transfected human thyroid cells and in derived tumors developed after in vitro irradiation
Authors: Zitzelsberger Horst , Bruch Jochen , Smida Jan , Hieber Ludwig , Peddie Clare M. , Bryant Peter E. , Riches Andrew C. , Fung Jingly , Weier Heinz‐Ulrich G. , Bauchinger Manfred
Published: November 2004

In vitro model cell systems are important tools for studying mechanisms of radiation‐induced neoplastic transformation of human epithelial cells. In our study, the human thyroid epithelial cell line HTori‐3 was analyzed cytogenetically following exposure to different doses of α‐ and γ‐irradiation and subsequent tumor formation in athymic nude mice. Combining results from G‐banding, comparative genomic hybridization, and spectral karyotyping, chromosome abnormalities could be depicted in the parental line HTori‐3 and in nine different HTori lines established from the developed tumors. A number of chromosomal aberrations were found to be characteristic for simian virus 40 immortalization and/or radiation‐induced transformation of human thyroid epithelial cells. Common chromosomal changes in cell lines originating from different irradiation experiments were loss of 8q23 and 13cen‐q21 as well as gain of 1q32‐qter and 2q11.2‐q14.1. By comparison of chromosomal aberrations in cell lines exhibiting a different tumorigenic behavior, cytogenetic markers important for the tumorigenic process were studied. It appeared that deletions on chromosomes 9q32‐q34 and 7q21‐q31 as well as an increased copy number of chromosome 20 were important for the tumorigenic phenotype. A comparative breakpoint analysis of the marker chromosomes found and those observed in radiation‐induced childhood thyroid tumors from Belarus revealed a coincidence for a number of chromosome bands. Thus, the data support the usefulness of the established cell system as an in vitro model to study important steps during radiation‐induced malignant transformation in human thyroid cells. © 2001 Wiley‐Liss, Inc.
Effect of Three Chlorinated Pesticides on hsrω Stress gene in Transgenic Drosophila melanogaster
Authors: Chowdhuri D. Kar , Nazir Aamir , Saxena D. K.
Published: November 2004

Expression of hsrω stress gene in the third‐instar larvae of 951‐lacZ2
(hsrω‐lacZ having–844pb sequence) and 498‐lacZ1
(hrsω‐lacZ having –498bp sequence) strains of Drosophila melanogaster
at LC50 and lower dietary concentrations of hexachlorocyclohexane (HCH) pentachlorophenol
(PCP), and endosulfan was examined in relation to larval mortality by β galactosidase activity,
vital dye staining, and salivary gland polytene chromosome puffing. Our results showed that both HCH and PCP at
lower concentrations evoked strong hsrω stress gene expression in the larval tissues while
endosulfan did not. On the other hand, puffing data revealed that endosulfan at lower doses, induced
well‐developed puff at the resident site (93D) of the hsrω gene but the transgenic
sites (30B in 951‐lacZ2 and 44B in 498‐lacZ1 strain) did not show any
well‐developed puff. Regression in hsrω stress gene expression in 951‐lacZ2 strain at
LC50 concentrations of HCH and PCP after 48 h was concurrent with extensive tissue damage as evident
by trypan blue staining. Similarly, strong hsrω expression was accompanied by insignificant trypan
blue staining in the larval tissues of this strain after shorter duration of exposure (2–12 h)
to these toxicants. Although endosulfan under similar experimental condition did not induce hsrω,
strong trypan blue staining indicated extensive tissue damage after 48 h of exposure. The present study suggests
that all the three toxicants pose cytotoxic potential to Drosophila. While protective role of this stress
gene was evident at the initial stages of exposure, extensive tissue damage in the later stages of intoxication
accompanied by autorepression of hsrω led to larval mortality. The study further suggests that
–844bp upstream sequence of the gene is adequate for hsrω inducibility against HCH and PCP
but not for endosulfan for which responsive elements may be searched further upstream. © 2001 John Wiley
& Sons, Inc. J Biochem Mol Toxicol 15:173–186, 2001
Activation of the Ah Receptor Signaling Pathway by Prostaglandins
Authors: Seidel Shawn D. , Winters Greg M. , Rogers William J. , Ziccardi Michael H. , Li Violet , Keser Bart , Denison Michael S.
Published: November 2004

The aryl hydrocarbon receptor (AhR) is a ligand‐dependent transcription factor that mediates
many of the biological and toxicological actions of a diverse range of chemicals, including the environmental
contaminant 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD, dioxin). Although no
endogenous physiological ligand for the AhR has yet been described, numerous studies support the existence of
such a ligand(s). Here we have examined the ability of prostaglandins and related chemicals to
activate the AhR signaling system. Using two AhR‐based bioassay systems we report that relatively high
concentrations of several prostaglandins (namely, PGB3, PGD3, PGF3α,
PGG2, PGH1, and PGH2) can not only stimulate AhR transformation and DNA
binding in vitro, but also induce AhR‐dependent reporter gene expression in mouse hepatoma cells in
culture. PGG2 also induced AhR‐dependent reporter gene expression to a level three‐to
four fold greater than that observed with a maximal inducing dose of TCDD. Sucrose gradient ligand binding
analysis revealed that PGG2 could competitively displace [3H]TCDD from the AhR. Overall,
our results demonstrate that selected prostaglandins are weak agonists for the AhR and they represent a
structurally distinct and novel class of activator of the AhR signal transduction pathway. © 2001 John Wiley
& Sons, Inc. J Biochem Mol Toxicol 15:187–196, 2001
Effect of Cadmium and Aluminum Intake on the Antioxidant Status and Lipid Peroxidation in Rat Tissues
Authors: El‐Maraghy Shohda A. , Gad Mohamed Z. , Fahim Atef T. , Hamdy Mohamed A.
Published: November 2004

This work aimed to study the relationship between the accumulation of cadmium (Cd) or aluminum (Al) in certain tissues and the levels of lipid peroxides as well as tissue antioxidants. To carry out such investigations, CdCl2 was given to rats in two dose levels; 0.5 or 2.0 mg/kg i.p for 1 day or daily repeated doses for 2 weeks. Al was given as AlCl3 either in a single dose of 100 mg/kg or daily repeated doses of 20 mg/kg for 2 and 4 weeks. The measured parameters were tissue malondialdehyde (MDA, index of lipid peroxidation) and reduced glutathione (GSH) levels as well as the activities of glutathione peroxidase (GSH‐PX), glutathione reductase (GSSG‐R), and glucose‐6‐phosphate dehydrogenase (G‐6‐PDH) enzymes. Liver and kidney functions were assessed by measuring serum alanine aminotransferase (ALT) and alkaline phosphatase (ALP) activities as well as serum urea and creatinine concentrations. Cd and Al concentrations in the studied tissues were also measured. Results indicated that tissue Cd was significantly increased after administration of either Cd doses. After a single dose of 0.5 or 2.0 mg/kg CdCl2, the increase in tissue Cd levels were accompanied by an increase in MDA and a decrease in GSH levels. On the other hand, after repeated administration of Cd, tissue Cd accumulation was accompanied by increased hepatic and renal GSH levels with decrease in MDA content and a decrease in GSH‐PX activity in liver. Liver function was affected at all dose regimens, whereas kidney function was affected only after 2 weeks administration of the higher dose. In Al treated rats, Al concentration was shown to be increased in liver much more than in brain. This was accompanied by a slight decrease in hepatic GSH level after 2 weeks and a decrease in GSH‐PX activity after 4 weeks. Liver function was affected only after repeated
injection of Al for 2 or 4 weeks. In general, Al administration exhibited safer pattern than Cd. © 2001 John Wiley & Sons, Inc. J Biochem Mol Toxicol 15:207–214, 2001
A Novel Nonhemorragic Protease from the African Puff Adder (Bitis Arietans) Venom
Authors: Nok Andrew J.
Published: November 2004

A nonhemorrhagic proteinase B‐20 from the venom of Bitis arietans has been purified to apparent electrophoretic homogeneity by chromatography on Sephadex G–100, Q‐Sepharose, and CM‐cellulose. It has a molecular weight of 20 k Da as determined by size exclusion chromatography on Sephadex G‐100 and migrated as a single 20‐k Da band on SDS polyacrylamide. It has an optimum pH of 6–8 and is inactive at pH 4.0. EDTA and 1,10‐phenanthroline strongly inhibited the enzyme suggesting it is a metalloenzyme. Also it is inhibited by antipain but is unaffected by trasylol, antitrypsin, and pepsptatin. Colombin, an identified active component of Aristolochia albida used in the treatment of snake poisoning, did not inhibit the protease activity. It lost over 90% of its activity in the presence of 0.5 μM Hg2+ but the inhibition was completely blocked in the presence of 10 μM mercaptoethanol implicating sulfyhydryl groups in the catalytic entity of the protein. The activity was also inhibited competitively by glutathione and cysteine with inhibition binding constants Ki of 240 and 40 μM, respectively. The enzyme is unaffected by several divalent cations but activated by 1 mM Fe3+. It had a prolyl endopeptidase and thermolysin‐like activity. The enzyme displayed a fast acting α‐fibrinolytic and delayed γ‐fibrinolytic activity when tested on human fibrinogen. The relevance of these findings is discussed © 2001 John Wiley & Sons, Inc. J Biochem Mol Toxicol 15:215–220, 2001
A scalable parallel Monte Carlo method for free energy simulations of molecular systems
Authors: Khan Malek O. , Kennedy Gareth , Chan Derek Y. C.
Published: November 2004

We present a method of parallelizing flat histogram Monte Carlo simulations, which give the free energy of a molecular system as an output. In the serial version, a constant probability distribution, as a function of any system parameter, is calculated by updating an external potential that is added to the system Hamiltonian. This external potential is related to the free energy. In the parallel implementation, the simulation is distributed on to different processors. With regular intervals the modifying potential is summed over all processors and distributed back to every processor, thus spreading the information of which parts of parameter space have been explored. This implementation is shown to decrease the execution time linearly with added number of processors. © 2004 Wiley Periodicals, Inc. J Comput Chem 26: 72–77, 2005
A family of graphs and the degree/diameter problem
Authors: Exoo Geoffrey
Published: November 2004

We investigate a family of graphs relevant to the problem of finding large regular graphs with specified degree and diameter. Our family contains the largest known graphs for degree/diameter pairs (3, 7), (3, 8), (4, 4), (5, 3), (5, 5), (6, 3), (6, 4), (7, 3), (14, 3), and (16, 2). We also find a new bound for (3, 6) by an unrelated method. © 2001 John Wiley & Sons, Inc. J Graph Theory 37: 118–124, 2001
Determination of alkaloids in Sophora flavescens ait. and Sophora viciifolia Hance by capillary zone electrophoresis
Authors: Su Xiaodan , Wang Xiukun , Li Yan , Li Jiashi , Yan Yuning , Chen Yuting , Liu Huwei
Published: November 2004

Capillary zone electrophoretic (CZE) separation of pharmacologically active alkaloids, matrine, sophocarpine, sophoridine, oxymatrine, and oxysophocarpine, was systematically optimized, and their contents in different parts of Sophora species were quantitatively determined within 16 min under the following optimized conditions: 0.04 mol/L citrate buffer system at pH 4.5, applied voltage 30 kV, capillary temperature 25°C, and diode array detection at 201 nm. The recoveries are from 90 to 108%, with repeatability ranging from 0.7 to 4.2% (relative standard deviation) and the detection limits ranging from 0.032 to 0.070 mg/mL (signal to noise ratio=3). The proposed CZE method is suitable for routine analysis and quality control of herbal medicines that contain these alkaloids. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 221–226, 2001
Reference steroid profiles in 0 to 3 day old neonates*
Authors: Bekker L. C. , Bester M. J. , Hurter P.
Published: November 2004

The excretion of 16α‐hydroxypregnenolone, 16α‐hydroxy‐DHEA, and 11‐oxo‐pregnanetriol was studied in 28 neonates with unambiguous genitalia. The 16α‐hydroxypregnenolone:16α‐hydroxy‐DHEA ratio was determined and compared with the steroid ratios described by Shackleton and by Reynolds, and used to diagnose neonates with congenital adrenal hyperplasia. The technique used was capillary gas chromatography after solid phase extraction, enzymatic hydrolysis, and derivatization of the analytes. Duplicate analyses were performed to provide identification (mass selective detection–quadrupole ion trap) and quantification (flame ionization detection). © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 250–254, 2001
High‐order method‐of‐moments solution of the scattering by three‐dimensional PEC bodies using quadrature‐based point matching
Authors: Gedney Stephen D.
Published: November 2004

In this paper, a novel high‐order method‐of‐moments solution of the electric‐ and magnetic‐field integral equations is presented. It is shown that, after choosing a smooth set of basis and testing functions, a simple transformation can be performed rendering a point‐based discretization of the integral equation at discrete quadrature points. Through numerical studies, it is shown that the proposed method results in exponential error convergence of the RCS for smooth three‐dimensional scattering structures. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 303–309, 2001.
Analysis of a new bandpass filter with two ring DRs using the FDTD method
Authors: Hwang Ho‐Tark , Lim Sang‐Ho , Oh Soon‐Soo , Jeong Jichai , Kim Young‐Sik
Published: November 2004

In this paper, a new bandpass filter inserting a microstrip‐line resonator between two ring dielectric resonators is described in an MIC environment. This filter is designed using the general filter design technique, and is analyzed using the FDTD method. The designed result shows good agreement with the experimental and simulated ones. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 319–322, 2001.
Shielding effect using cascaded metallic holes in microwave circuits
Authors: Zeid A. , Baudrand H. , Peuch J. C.
Published: November 2004

The problem of electromagnetic shielding between elements of microelectronic circuits has been studied by using a new technique (the via holes technique). Metallic squares and truncated square cross sections approximate each metallic circle cross section. A comparison between the adjacent and a staggered arrangement of via holes has been illustrated theoretically and experimentally. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 322–324, 2001.
Performance tolerance in microprism‐type bent waveguides
Authors: Hsu Jui‐Ming , Lee Ching‐Ting
Published: November 2004

By taking into account the inevitable fabrication tolerance, we present two kinds of performance‐tolerant models for microprism‐type bent waveguides. The optical transmitted power efficiency is investigated by using the fast Fourier transform beam propagation method and the orthogonality overlap integral. We demonstrate the dependence of the performance tolerance region on practical fabrication parameters. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 328–332, 2001.
Polarization‐insensitive wavelength conversion with a constant output linear polarization allowing the realization of an active polarization controller
Authors: Soto H. , Erasme D. , Zitlalpopoca J.
Published: November 2004

In this work, we demonstrate theoretically and experimentally a technique allowing us to realize a polarization‐insensitive wavelength conversion with an output beam whose polarization state is unique and linear for all input signal polarization states. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 344–348, 2001.
Circularly polarized dielectric resonator antenna excited by dual conformal strips of unequal lengths
Authors: Wong W. C. , Leung K. W.
Published: November 2004

A circularly polarized cylindrical dielectric resonance antenna excited by two conformal strips of unequal lengths is studied experimentally. By using unequal strip lengths, two nearly degenerate orthogonal modes are excited and circularly polarized fields are generated. The measured return loss, axial ratio, radiation pattern, and antenna gain of the configuration are discussed. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 348–350, 2001.
Three‐dimensional weak‐form conjugate‐ and biconjugate‐gradient FFT methods for volume integral equations
Authors: Zhang Z. Q. , Liu Q. H.
Published: November 2004

A large‐scale three‐dimensional volume integral equation solution for electromagnetic radiation and scattering problems remains a great challenge in spite of many ongoing research efforts. The conventional method of moments, although accurate and flexible, is limited to small‐scale problems because of its large requirement of computer memory and computation time. In this paper, we develop two fast methods, the weak‐form conjugate‐ and biconjugate‐gradient FFT methods, to solve the Fredholm integral equation of the second kind arising from Maxwell's equations in three dimensions. The weak form is a modified version of the Zwamborn–van den Berg formulation, where the singularity is circumvented by employing the weak‐form discretization by rooftop vectorial basis and testing functions. Both weak‐ form CG–FFT and BCG–FFT methods require O(N log2 N) CPU time, and O(N) computer memory, but the latter converges three–six times faster than the CG–FFT method. We validate the numerical results by comparing them with analytical solutions to multilayer spherical media, and with other published results. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 350–356, 2001.
Comments on “Returning to the Post Constraints”
Authors: Lakhtakia Akhlesh , Weiglhofer Werner S.
Published: November 2004

Dmitriev [Microwave Opt Technol Lett 27 (2000) 201–203] recently contended that the so‐called Post constraint holds only for reciprocal and spatiotemporally local media. Having provided general proofs earlier, we point out that the Post constraint thus is not restricted, but applies to all linear media—whether spatiotemporally local or nonlocal, spatiotemporally homogeneous or nonhomogeneous, and reciprocal or nonreciprocal. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 363–363, 2001.
Electronic cooling of a passive resistor by a microwave transistor amplifier
Authors: Venguer A. P. , Medina J. L. , Chávez R. A.
Published: November 2004

Experimental research on the influence of a transistor amplifier on the noise power value of a passive resistor was performed. An expression for the noise temperature cooling using an attenuator–amplifier circuit is proposed, avoiding physical cooling. A significant deviation of the electromagnetic radiation value from the linear characteristics of a passive resistor is obtained into a given operation bandwidth of the amplifier for relatively small attenuation values and as a function of the input return losses. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 423–427, 2001.
Detection of transgene in progeny at different developmental stages following testis‐mediated gene transfer
Authors: Yonezawa Tomohiro , Furuhata Yasufumi , Hirabayashi Keiji , Suzuki Masatoshi , Takahashi Michio , Nishihara Masugi
Published: November 2004

We recently reported that exogenous DNA injected into testis as a liposome complex can be transferred into the egg via sperm by natural mating and integrated in the genome (testis‐mediated gene transfer: TMGT). Here, we studied the efficiency of each of the several liposomes in associating foreign DNA with sperm, the expression of an introduced gene in early embryos, and the presence of the DNA in fetuses and pups at different ages. The CMV/β‐actin/EGFP fusion gene, encapsulated with different liposomes, was injected into rat testis, and spermatozoa in the cauda epididymis were obtained 1, 4, and 14 days after injection. We tested each of the 8 liposomes, and found that only 2, DMRIE‐C and SuperFect, led to the detection of foreign DNA on all of the days examined, with relatively higher ratios of rats having positive sperm. By means of TMGT using either of those two liposomes, more than 80% of morula‐stage embryos expressed EGFP, as observed by fluorescence microscopy. Then we detected introduced DNA in the progeny by PCR and Southern dot blot, and found that the ratio of animals carrying the foreign DNA decreased as they developed, and that only a part of postpartum progeny were foreign‐DNA‐positive with high incidence of mosaicism. These results suggest that, although, the success rate is still limited, foreign DNA could be integrated into the genome of the progeny by TMGT at least under specific experimental conditions, the efficiency of which depends largely on the characteristics of the liposome. The results also suggest that TMGT could be applicable to fetal gene therapy as well as to the generation of transgenic animals. Mol. Reprod. Dev. 60: 196–201, 2001. © 2001 Wiley‐Liss, Inc.
Molecular Sturmians. Part 1*
Authors: Avery John , Shim Rune
Published: November 2004

Sturmian methods for solving the Schrödinger equation for an electron moving in the field of a number of nuclei are reviewed. The problem is approached in direct space, although momentum‐space techniques, including the use of hyperspherical harmonics, are used to evaluate the necessary integrals. In Part 2, these many‐center one‐electron solutions, with weighted potentials, will be used to build up correlated solutions to the many‐electron Schrödinger equations of molecules. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 83: 1–10, 2001
Quantum chemistry study of proteins in bacterial photosynthetic reaction center
Authors: Shen Ling‐Ling , Zhang Xiao‐Dong , Zhang Qi‐Yuan
Published: November 2004

Quantum chemistry study on proteins L and M in the Rhodopseudomonas viridis (Rh. viridis) photosynthetic reaction center (PRC) are presented. The calculations were performed at ab initio level with Clementi minimal basis set by means of the overlapping‐dimer approximation (ODA)–extended negative factor counting (ENFC) method. Additional point charges were added to individual residues to simulated ionized aqueous environment of the proteins in the calculations. Meanwhile, the electronic structure of protein complex MH (protein M plus the α‐helix segment of protein H) was studied as well to examine the weak interaction between proteins M and H. As the first case of global quantum chemistry calculation for proteins in PRC, details of the electronic structure and the influence of proteins on the electron transfer process (ET) were studied. Moreover, new three‐dimensional structure plots of subunit L and M were given based on the distribution of the components of frontier orbitals in order to more clearly understand the structure–function relationship of the proteins in electron transfer reactions. Calculation results indicated that the components of frontier orbitals are extremely localized at individual residues. Amino acid residues, having contributed to the frontier orbitals of protein L, are located at the flexible random area of L, while those having contributed to the frontier orbitals of protein M are located at the rigid α‐helix area. This asymmetry of proteins L and M provides new understanding the ET reaction that takes place mainly along branch L in the PRC of Rh. viridis. Meanwhile, there is frontier orbital localized amino acid distribution around the V‐shaped pocket areas of protein L (M) that were expected to have an important interaction with QA (QB). All results indicate that protein provided a heterogeneous environment for pigment molecules and some important interaction between protein residues and pigment molecules are worthy of further investigation. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 83: 30–40, 2001
Structure and stability of X4Y4H4 (XY=CC, BN)
Authors: Yin Ping , Chen Xian‐Yang , Li Chong‐De , Xin Xin‐Quan
Published: November 2004

Ab initio calculations have been carried out to study the structures and relative stabilities of the planar eight‐membered ring B4N4H4 and its isoelectronic species C8H4 at the HF/6‐31G*, MP2/6‐31G*, MP2/6‐311G**, and MP4SDQ/6‐31G* levels. The analyses of Milliken population, vibration frequencies, π‐molecular orbital components, and orbital energy levels were used to evaluate the relative stabilities of these two similar systems. The homodesmotic reactions were also taken to be a useful index of relative stability for X4Y4H4 (XY=CC, BN) and gave the resonance energies with MP4SDQ/6‐31G* of C8H4 (−37.2 kcal/mol) < B4N4H4 (−29.2 kcal/mol). Furthermore, we calculated the thermodynamic functions of these reactions to discuss the influence of temperature. It is concluded that B4N4H4 may exist in theory and could be a little more stable than C8H4. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 82: 293–298, 2001
Expressing kinetic‐energy for vibration–rotation motions in general rotating systems of axes and introducing quasirectilinear vibrational coordinates to simplify Hamiltonian forms
Authors: Okuno Yoshishige
Published: November 2004

To understand how the internal and rotational motions of a polyatomic system depend on which rotating system of axes is selected, we derived the explicit form of the atomic velocities determined by an observer stationed on the general rotating system of axes. Using the derived velocities, we formulated the kinetic energy expression for vibration–rotation motions with respect to the rotating system of axes. From this expression, we clarified covariant metric tensors under zero angular momentum, which have been confused with an erroneous expression even in the professional literature, and the relationship between the kinetic energy expression and the rotating system of axes. Furthermore, to simplify the Hamiltonian form, we introduced quasirectilinear vibrational coordinates to describe the Hamiltonian. The resulting Hamiltonian form is superior to those of the previous studies in that the kinetic and potential energy expressions are simple and the vibrational frequencies are independent of the original internal coordinates used. In fact, we show that its application for three examples is useful. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 83: 22–29, 2001
Algebraic solutions for point groups: The octahedral group for the group chain O⊃T⊃C3
Authors: Fan Peng‐Dong
Published: November 2004

Using the right‐induced technique and the eigenfunction method, concise algebraic expressions of the projection operators for both single‐valued and double‐valued representations are found for the group chain O⊃T⊃C3 in terms of the projection operators of T⊃C3. Extremely simple relations are discovered between the symmetry adapted functions (SAFs) of the groups T and O; namely the SAFs of the subgroup T which have proper symmetry are the SAFs of the group O. The projection operators and SAFs are functions of only the quantum numbers of the group chain [the analogy of ( j,m) for the group chain SO3⊃SO2], without involving any irreducible matrix elements. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 83: 259–270, 2001
Development of speedy and high‐sensitivity pen system for writing pressure and writer identification
Authors: Kikuchi Mami , Akamatsu Norio
Published: November 2004

This paper describes a pen input system which was developed to obtain subtle writing pressure data. When the writing pressure is small, a conventional electronic pen cannot collate writing pressure data sufficiently. However, the developed pen can collate sufficient data with precision. The developed pen can manipulate any high‐speed signatures by means of high‐speed writing pressure processing. Further, in the pen input system, writing pressure data can be obtained by using only the pen, without any tablet.

The writing pressure information obtained by the developed pen input system is analyzed and applied to writer identification. © 2001 Scripta Technica, Syst Comp Jpn, 32(6): 1–12, 2001
A change‐point perspective on the software failure process
Authors: Zou Feng‐Zhong
Published: November 2004

In the software reliability growth phase, the nature of the failure data is, in a sense, determined by the software testing process. There are many factors that affect software testing. These factors are unlikely to all be kept stable during the entire process of software testing, with the result that the underlying statistics of the failure process is likely to experience major changes. In this case, it is appropriate to use the change‐point method in the reliability analysis. This paper considers a change‐point model and proposes a change‐point estimator for reliability analysis. Experimentally, the change‐point method is applied to a real dataset, which verifies the validity of the model. A Monte Carlo simulation study on the asymptotic properties of the estimator indicates that the model is consistent. Copyright © 2003 John Wiley & Sons, Ltd.
Polymer surface science
Authors: Opdahl A. , Hoffer S. , Mailhot B. , Somorjai G.A.
Published: November 2004

Molecular level studies of the structure and mechanical properties of polymer surfaces have been carried out by sum frequency generation (SFG) surface vibrational spectroscopy and atomic force microscopy (AFM). The surfaces of different grades of polyethylene and polypropylene have been characterized—including during the glass transition and when mechanically stretched. Copolymers that have hard and soft segments with different glass transition temperatures show phase separation, an effect of hydrogen bonding between the hard and soft segments, that influences their adhesive and friction properties. AFM and SFG show that low surface energy additives migrate to the surface and alter the surface mechanical properties. Polymers, where the chemical nature of the end groups is different from the backbone, show surface segregation of the hydrophobic part of the chain in air and the hydrophilic part in water. Likewise, in miscible polymer blends, surface segregation of the more hydrophobic component in air and the more hydrophilic component in water is observed. This area of surface science requires increased attention because of the predominance of polymers as structural materials and as biomaterials. © 2001 John Wiley & Sons, Inc. and The Japan Chemical Journal Forum Chem Rec 1:101–122, 2001
Tryptophan synthase: A multienzyme complex with an intramolecular tunnel
Authors: Miles Edith Wilson
Published: November 2004

Tryptophan synthase is a classic enzyme that channels a metabolic intermediate, indole. The crystal structure of the tryptophan synthase α2β2 complex from Salmonella typhimurium revealed for the first time the architecture of a multienzyme complex and the presence of an intramolecular tunnel. This remarkable hydrophobic tunnel provides a likely passageway for indole from the active site of the α subunit, where it is produced, to the active site of the β subunit, where it reacts with L‐serine to form L‐tryptophan in a pyridoxal phosphate‐dependent reaction. Rapid kinetic studies of the wild type enzyme and of channel‐impaired mutant enzymes provide strong evidence for the proposed channeling mechanism. Structures of a series of enzyme‐substrate intermediates at the α and β active sites are elucidating enzyme mechanisms and dynamics. These structural results are providing a fascinating picture of loops opening and closing, of domain movements, and of conformational changes in the indole tunnel. Solution studies provide further evidence for ligand‐induced conformational changes that send signals between the α and β subunits. The combined results show that the switching of the enzyme between open and closed conformations couples the catalytic reactions at the α and β active sites and prevents the escape of indole. © 2001 John Wiley & Sons, Inc. and The Japan Chemical Journal Forum Chem Rec 1:140–151, 2001*
Bioorganic chemistry à la baguette: Studies on molecular recognition in biological systems using rigid‐rod molecules
Authors: Matile Stefan
Published: November 2004

Initial studies using rigid‐rod molecules or “baguettes” to address bioorganic topics of current scientific concern are reported. It is illustrated how transmembrane oligo(p‐phenylene)s as representative model rods can be tuned to recognize lipid bilayer membranes either by their thickness or polarization. The construction of otherwise problematic hydrogen‐bonded chains along transmembrane rods yields “proton wires,” which act by a mechanism that is central in bioenergetics but poorly explored by means of synthetic models. Another example focuses on multivalent ligands assembling rigid‐rod cell‐surface receptors into transmembrane dynamic arene arrays. The potassium transport mediated by these ligand‐receptor complexes provides experimental support for the potential biological importances of the controversial cation‐π mechanism. More complex supramolecular architecture is portrayed in the first artificial β‐barrels. It is shown how programmed assembly of toroidal rigid‐rod supramolecules in detergent‐free water permits control of diameter of the chemical nature of their interior. Reversed rigid‐rod β‐barrels are assembled to function as self‐assembled ionophores, ion channel models, and transmembrane nanopores. The potential of future intratoroidal chemistry is exemplified by encapsulation and planarization of β‐carotene in water and the construction of transmembrane B‐DNA at the center of a second‐sphere host‐guest complex à al baguette. © 2001 John Wiley & Sons, Inc. and The Japan Chemical Journal Forum Chem Rec 1:162–172, 2001
Business and the civil society: The missing dialectic
Authors: Reece John W.
Published: November 2004

The positive social impact of global commerce on an increasingly interdependent world is challenged by civil
society. A diversely supported backlash threatens political restrictions on the free market paradigm and loss of
globalization's momentum. Opposition is documented in the historical record and an expanding base of critical
literature. The power balance of the three components of society‐political, economic and civil is in flux.
Business's only stabilizing strategy is to acknowledge and act on its commensurate social responsibility.
Optimism is found in a minority of individual business actions, however the speed with which the majority will
adapt is crucial. © 2001 John Wiley & Sons, Inc.
Four visions of e‐commerce in Latin America in the year 2010
Authors: Montealegre Ramiro
Published: November 2004

Excitement is growing around the world about the Internet's potential to enable a global electronic commerce. The reality, however, differs a great deal depending on what part of the world we consider. In Latin America, the e‐commerce theme is often found in the popular press portraying it as a solution for multiple national problems and as a catalyst to propel the region to a stronger position in the world economy. Unfortunately, many of the “new” capabilities required to harness the economic benefit of e‐commerce, which emphasize value‐adding steps performed through and with information, are very scarce in the region. This article raises questions about Latin America's ability to exploit the Internet, and to implement and capitalize on e‐commerce applications. It underscores the region's need to engage in a future planning discourse about the adoption of e‐commerce within organizations, communities, and across traditional boundaries of competition and national borders. To start the dialogue, four scenarios are presented as “future snapshots” written from the vantage point of the year 2010. Each scenario considers issues regarding technological adoption and potential social responses, and discusses some of the critical assumptions about patterns observed in the region today and their implications for the future. © 2001 John Wiley & Sons, Inc.
Corporate ethical values in South Africa
Authors: Marta Janet K. Mullin , Singhapakdi Anusorn , Higgs‐Kleyn Nicola
Published: November 2004

This study analyzes the influence of a number of variables on the ethical decision making process of South
African marketers. Specifically, it measures the relative influences of ethical perception, idealism,
relativism, and corporate ethical values on the ethical intentions of the marketers. The target respondents were
practitioner members of the South African Institute of Marketing Management. The survey results indicate that
perception of an ethical problem and relativism are significant predictors of ethical intentions, as
hypothesized. The other two predictor variables (idealism and corporate ethical values) were not
significant. The results regarding idealism are generally consistent with those from previous studies, but
corporate ethical values has usually been found to be significant, and not just in the United States. These
nonsignificant findings are among the most intriguing of the study. © 2001 John Wiley & Sons, Inc.
Reactions to authority
Authors: Bu Nailin , Craig Timothy J. , Peng T.K.
Published: November 2004

Japanese, Taiwanese, and PRC employees responded to vignettes where they were asked to react to a
supervisor's direction. Multiple versions of the vignettes that varied systematically with respect to
company policies, peer consensus, and independent assessment were distributed to create a factorial design. PRC
employees were the most compliant, followed by Taiwanese, and then by Japanese employees. Compared with Japanese
and Taiwanese employees, PRC employees were more strongly influenced by company policies but less strongly
influenced by independent assessment. Peer consensus carried more weight among Japanese employees than among
Taiwanese and PRC employees, although the difference was statistically insignificant. © 2001 John Wiley
& Sons, Inc.
Long‐term transportation of ratfish, Hydrolagus colliei, and tiger rockfish, Sebastes nigrocinctus
Authors: Correia João P.S.
Published: November 2004

On December 10, 2000, five tiger rockfish, Sebastes nigrocinctus, and 10 ratfish, Hydrolagus colliei, were transported from Vancouver, Canada, to Lisbon, Portugal, for 51 and 44 hours, respectively. The transport vessels consisted of large circular tanks (1.0‐m diameter × 0.6 m high) and filtration was added to the rockfish tank only. Filtration consisted of a combination of cartridge and activated carbon, powered by a 12‐V bilge pump placed on the middle of the transport vessel. Water quality parameters (ammonia, temperature, and oxygen saturation) were tested during the transport, and an ammonia detoxifier was added to some of the transport vessels when ammonia concentration reached 0.25 mg/L. Sodium bicarbonate was also added for pH buffering. All animals survived the trip and the subsequent 4 weeks. The water quality monitoring and treatment regimen therefore seemed appropriate for this type of long‐term transportation. Zoo Biol 20:435–441, 2001. © 2001 Wiley‐Liss, Inc.
A comparison of physical activity levels in two contrasting elderly populations in Thailand
Authors: Henry C.J.K. , Webster‐Gandy J. , Varakamin C.
Published: November 2004

There is little information available on physical activity patterns in the elderly in developing countries. This is particularly important at a time when developing countries are in transition and show signs of moving toward Western style patterns of physical activity and social structure. This study is unique in that it compares the physical activity levels in two contrasting communities: a residential home and a rural community of elderly subjects in Thailand. Ninety elderly people living in a residential home and 78 elderly people living with their families in a rural community were recruited. The men in the rural community were slightly lighter and leaner than the men in the residential community, but the differences were not significant. However, the women were significantly (P < 0.001) heavier and fatter in the residential home than in the rural community. This is consistent with the higher levels of physical activity in the rural community. There was considerable variation in physical activity in this population. The physical activity level (PAL) values ranged from 1.21 to 1.73 in the residential home and from 1.21 to 3.08 in the rural community. This is apparently the first study of physical activity patterns in elderly subjects in a developing country. It highlights the variation in activity within the rural community and between both communities. The opportunities for the elderly living in the residential home to have active lifestyles are limited. It is likely that this will result in increased morbidity in the final years of life. Am. J. Hum. Biol. 13:310–315, 2001. © 2001 Wiley‐Liss, Inc.
Do “helpers at the nest” increase their parents' reproductive success?
Authors: Crognier Emile , Baali A. , Hilali M‐K.
Published: November 2004

“Helpers at the nest,” usually offspring of a preceding litter who contribute by feeding the young to increase the reproductive success of a breeding pair, are known in many species of birds and mammals. Although similar behaviors were described by ethnological observations in several human societies, there is a lack of data on their existence and role. This study of 794 reproductive life histories of post‐menopausal Berber women of Southern Morocco aims to provide such information. Results show that the presence of “probable helpers” in the household is related to higher fertility scores and is associated with improved survival of offspring to sexual maturity. In contrast to sparse observations from other human societies, there is no indication that child caretaking would be specific to eldest daughters. Although the association between offspring survival and helping patterns seems highly probable, there is no confirmation that child caretaking per se is the relevant variable. Contrary to nonhuman helpers at the nest, workloads of children range from housekeeping to light agricultural tasks, and are not focused on assisting younger siblings. The improvement of reproductive success is probably the result of multiple interactions, among which the network of kinship would play a role at both the levels of economy and reciprocal assistance. Am. J. Hum. Biol. 13:365–373, 2001. © 2001 Wiley‐Liss, Inc.