bluuebunny/crossref_metadata_2025 huggingface dataset:
EBNA3A Association with RBP-Jκ Down-Regulates c-mycand Epstein-Barr Virus-Transformed Lymphoblast Growth
Authors: Cooper Andrew , Johannsen Eric , Maruo Seiji , Cahir-McFarland Ellen , Illanes Diego , Davidson David , Kieff Elliott
Published: December 2002

Epstein-Barr virus nuclear antigen protein 3A (EBNA3A) is one of four EBNAs (EBNA-2, EBNALP, EBNA3A, and EBNA3C) through the cellular DNA sequence-specific transcription factor RBP-Jκ/CBF-1/CSL and are essential for conversion of primary B lymphocytes to lymphoblastoid cell lines (LCLs). In the present study, we investigated the effects of EBNA3A on EBNA2 activation of transcription in the IB4 LCL by conditionally overexpressing EBNA3A three- to fivefold. EBNA3A overexpression increased EBNA3A association with RBP-Jκ, did not change EBNA3C association with RBP-Jκ or EBNA or LMP1 expression, decreased EBNA2 association with RBP-Jκ, decreased c-mycexpression, and caused G0/G1growth arrest with prolonged viability. Expression of the fusion protein MycERTM in cells with conditional EBNA3A overexpression restored cell cycle progression and caused apoptosis. In contrast, MycER in the same cells without EBNA3A overexpression enhanced cell proliferation and did not increase apoptosis. These data indicate that EBNA3A overexpression inhibits protection from c-myc-induced apoptosis. In assays of EBNA2- and RBP-Jκ-dependent transcription, EBNA3A amino acids 1 to 386 were sufficient for repression equivalent to that by wild-type EBNA3A, amino acids 1 to 124 were unimportant, amino acids 1 to 277 were insufficient, and a triple alanine substitution within the EBNA3A core RBP-Jκ binding domain was a null mutation. In reverse genetic experiments with IB4 LCLs, the effects of conditional EBNA3A overexpression on c-mycexpression and proliferation did not require amino acids 524 to 944 but did require amino acids 278 to 524 as well as wild-type sequence in the core RBP-Jκ binding domain. The dependence of EBNA3A effects on the core RBP-Jκ interaction domain and on the more C-terminal amino acids (amino acids 278 to 524) required for efficient RBP-Jκ association strongly implicates RBP-Jκ in c-mycpromoter regulation.
EXACT SOLUTIONS OF EFFECTIVE-MASS SCHRÖDINGER EQUATIONS
Authors: GÖNÜL BÜLENT , ÖZER OKAN , GÖNÜL BEŞIRE , ÜZGÜN FATMA
Published: December 2002

We outline a general method for obtaining exact solutions of Schrödinger equations with a position-dependent effective mass and compare the results with those obtained within the frame of supersymmetric quantum theory. We observe that the distinct effective mass Hamiltonians proposed in the literature in fact describe exactly equivalent systems having identical spectra and wave functions as far as exact solvability is concerned. This observation clarifies the Hamiltonian dependence of the band-offset ratio for quantum wells.
VARIATION OF G, Λ(4) AND VACUUM ENERGY FROM BRANE-WORLD MODELS
Authors: DE LEON J. PONCE
Published: December 2002

In brane-world theory in five dimensions, the bulk metric is usually written in Gaussian coordinates, where g4μ = 0 and g44 = -1. However, the choice g44 = -1 is an external condition, not a requirement of the field equations. In this paper we study the consequences of having g44 = εΦ2, where ε = ±1 and Φ is a scalar function varying with time, [Formula: see text]. This varying field entails the possibility of variable fundamental physical "constants". These variations are different from those predicted in scalar–tensor and multidimensional theories. We solve the five-dimensional equations for a fixed brane and use the brane-world paradigm to determine the fundamental parameters in the theory, which are the vacuum energy σ, the gravitational coupling G and the cosmological term Λ(4). We present specific models where these physical quantities are variable functions of time. Different scenarios are possible but we discuss with some detail a model for which Ġ/G ~ H and Λ(4) ~ H2, which seems to be favored by observations. Our results are not in contradiction to previous ones in the literature. In particular, to those where the brane is described as a domain wall moving in a static Sch–AdS bulk. Indeed these latter models in RS scenarios describe the same space–time as other solutions (with fixed brane) in Gaussian coordinates with [Formula: see text]. We conclude that the introduction of a time-varying Φ in brane-world theory yields a number of models that show variation in the fundamental physical "constants" and exhibit reasonable physical properties.
CLOSED SUPERSTRING IN NONCOMMUTATIVE COMPACT SPACE–TIME
Authors: KAMANI DAVOUD
Published: December 2002

In this paper we study the effects of noncommutativity on a closed superstring propagating in the space–time that is compactified on tori. The effects of compactification and noncommutativity appear in the momentum, quantization, supercurrent, super-conformal generators and in the boundary state of the closed superstring emitted from a D p-brane with the NS ⊗ NS background B-field.
BROKEN UNITARITY OF THE SM
Authors: LI BING AN
Published: December 2002

It is shown that because of axial-vector coupling and vector coupling between boson and fermions of different masses, the boson field has four independent components. The spin-0 component has problem of negative probability. The unitarity of the theory is broken. These results are applied to the SM. The masses are mϕ0 = 3.78×1014 GeV and mϕ± = 9.31×1013 GeV respectively. The unitarity of the SM is broken at about ~ 1014 GeV . The masses of W and Z can be generated by two types of interactions mentioned above without Higgs mechanism. The masses of the W and the Z bosons are obtained to be [Formula: see text] and [Formula: see text] with ρ≃1. [Formula: see text].
THE PROPERTIES OF NONADIABATIC FLUCTUATIONS IN STRONGLY COUPLED ELECTRON–PHONON SYSTEMS WITH CORRELATED DISPLACEMENT AND SQUEEZING
Authors: PANG XIAO-FENG
Published: December 2002

A new variational ansatz for the coherent phonons with correlated displacement and squeezing, including interaction with electrons are used to study the properties of (i) the nonadiabatic phonon fluctuation on the ground state, (ii) the uncertainty principle, (iii) the phonon-staggered ordering, and (iiv) the charge-density wave order, of the systems due to fluctuations of the electron density in a coupled electron–phonon systems. The results obtained show that the correlation effect can lower the energy of the ground state of the systems, enhance the stabilization of the polaron and suppress the quantum increase of the classical polaron narrowing of electron band. Moreover, it add to the effects of nonadiabaticity on the minimum quantum uncertainty for the phonon coordinate by a strong coupling with the electron density for a large squeezing as compared with the adiabatic case and the uncorrelated case. Therefore, the new ansatz which can represent the correlation effects of displacement and squeezing is especially relevant for system with sufficiently large squeezing and strong coupling.
MASS DEPENDENCE OF p-NUCLEUS TOTAL REACTION CROSS SECTION AND GAMBHIR–PATIL NUCLEON DENSITY DISTRIBUTION
Authors: MADANI JAMAL H.
Published: December 2002

Total reaction cross sections for 50 and 100 MeV protons have been calculated for several nuclei using Gambhir–Patil semi-phenomenological nucleon density in the Coulomb modified Glauber model. It is shown that the semi-phenomenological nucleon density distribution provides quite satisfactory description of the observed A-dependence of the proton reaction cross sections.
COLLECTIVE BANDS IN 68Se
Authors: TRIPATHY K. C. , SAHU R.
Published: December 2002

The collective bands of the N = Z nucleus 68 Se are studied within our deformed configuration mixing shell model based on Hartree–Fock states. The configuration space consists of the spherical single particle orbits 1p3/2, 0f5/2, 1p1/2 and 0g9/2 with 56 Ni as the inert core. A modified Kuo interaction for this basis space has been used in our calculation. The calculated ground band, K = 2+ excited band and the K = 5- excited band agree reasonably well with the experiment. Our calculation shows that the ground band is essentially of oblate shape and the excited K = 2+ band is of prolate shape. This is in agreement with the conclusions drawn from the recent experimental analysis.
EIKONAL DESCRIPTION OF 12C–12C ELASTIC SCATTERING IN TERMS OF PHENOMENOLOGICAL EFFECTIVE NN POTENTIAL
Authors: AHMAD I. , ABDULMOMEN M. A. , ALVI M. A.
Published: December 2002

A phenomenological method of analysis for heavy-ion elastic scattering data at intermediate energies is proposed within the framework of the optical limit approximation of the Glauber multiple scattering theory. The essential point of our method is to evaluate the NN scattering amplitude in terms of a phenomenological effective NN potential the parameters of which are varied to fit the experimental data. It is applied to analyze 12C–12C elastic scattering data in the energy range of 25–200 MeV/nucleon with a good degree of success.
FUSION OF LIGHT PROTON-RICH EXOTIC NUCLEI AT NEAR-BARRIER ENERGIES
Authors: BANERJEE P. , KRISHAN K. , BHATTACHARYA S. , BHATTACHARYA C.
Published: December 2002

We study, theoretically, the fusion of the light proton-rich exotic nuclei 17 F and 8 B at near-barrier energies in order to investigate the possible role of breakup processes on their fusion cross sections. To this end, coupled channel calculations are performed, considering the couplings to the breakup channels of these projectiles. In case of 17 F , the coupling arising out of the inelastic excitation from the ground state to the bound excited state and its couplings to the continuum have also been taken into consideration. It is found that the inelastic excitation/breakup of 17 F affect the fusion cross sections very nominally even for a heavy target like Pb. On the other hand, calculations for fusion of the one-proton halo nucleus 8 B on a Pb target show a significant suppression of the complete fusion cross section above the Coulomb barrier. This is due to the larger breakup probability of 8 B as compared to that of 17 F . However, even for 8 B , there is little change in the complete fusion cross sections as compared to the no-coupling case at sub-barrier energies.
COLLECTIVE EXCITATIONS OF THE154SmNUCLEUS AT THE FEL ⊗ LHC COLLIDER
Authors: GULIYEV E. , YAVAŞ Ö. , SULTANSOY S.
Published: December 2002

The physics search potential of the recently proposed FEL ⊗ LHC collider is illustrated in the sample of the collective excitations of the154Sm nucleus. In this facility the accelerated fully ionized nuclei will "see" the keV energy FEL photons as a MeV energy laser beam. The main advantages compared to the traditional methods are the tunability, monochromaticity and high polarization of the FEL beam. The advantages result in higher statistics and the possibility to investigate individual levels.
NEUTRINO MASS FROM BETA DECAY OF THE FREE NEUTRON
Authors: TEGEN R. , MILLER H. G.
Published: December 2002

We calculate the beta decay rate of the free neutron including effects due to (i) a neutrino mass around 1 eV, (ii) deviations from the leptonic V-A structure, (iii) nucleon form factors [Formula: see text], GA(q2), and (iv) W- propagation. At the end-point energies linear neutrino mass effects in [Formula: see text] are almost exclusively kinematical. If the neutrino spectrum is (almost) degenerate, neutrino oscillations cannot uniquely determine the mass of the neutrino, and direct mass determinations become necessary. The traditional Kurie plot and a partially integrated decay rate are found to be sensitive to a neutrino mass between 1 eV and 3 eV.
EXPERIMENTAL STUDY OF SINGLE-ELECTRON-CAPTURE CROSS SECTIONS BY LOW-ENERGY $N^+_2$ AND N+ IONS IN N2 MOLECULAR GAS
Authors: HASAN A. T. , GRAY T. J.
Published: December 2002

Absolute total cross sections for single-electron-capture are measured for [Formula: see text] and N+ ions traversing N2 molecular gas of collision energies in the range of 0.60 to 1.5 keV. These cross sections are found to be in the range of 3.97 - 6.25 Å2 for [Formula: see text] ions, and in the range of 0.46 - 1.67 Å2 for N+ ions. A comparison is made between the present measurements of the total cross sections of the N+ + N2 system and all the experimental results, which are represented by B. G. Lindsay et al.,1 for the O+ + N2 system. The present measurements of the total cross section of the N+ + N2 system are in partial agreement with measurements of B. G. Lindsay et al.,1 and in an excellent agreement with the measurements of Moran et al.,2 The present measurements of the total cross sections of the [Formula: see text] system are compared to the theoretical calculations and the experimental results of the same system.23 The results are in disagreement with each other.
A GENERATION MODEL OF THE FUNDAMENTAL PARTICLES
Authors: ROBSON B. A.
Published: December 2002

A new classification of the fundamental particles based upon the use of only three additive quantum numbers (charge, particle number, generation quantum number) compared with the nine additive quantum numbers of the Standard Model (charge, lepton number, muon lepton number, tau lepton number, baryon number, strangeness, charm, bottomness, topness) is presented. This classification provides a new basis for the weak isospin symmetry characteristic of both leptons and quarks.
USE OF COMBINED SYSTEM DEPENDABILITY AND SOFTWARE RELIABILITY GROWTH MODELS
Authors: HECHT MYRON , HECHT HERBERT , AN XUEGAO
Published: December 2002

This paper describes how MEADEP, a system level dependability prediction tool, and CASRE, a software reliability growth prediction tool can be used together to predict system reliability (probability of failure in a given time interval), availability (proportion of time service is available), and performability (reward-weighted availability). The system includes COTS hardware, COTS software, radar, and communication gateways. The performability metric also accounts for capacity changes as processors in a cluster fail and recover. The Littlewood Verall and Geometric model is used to predict reliability growth from software test data this prediction is integrated into a system level Markov model that incorporates hardware failures and recoveries, redundancy, coverage failures, and capacity. The results of the combined model can be used to predict the contribution of additional testing upon availability and a variety of other figures of merit that support management decisions.
THEORY, METHOD AND APPLICATIONS OF THE UNIFORM DESIGN
Authors: FANG KAI-TAI
Published: December 2002

In modern techniques and science one meets design problems for multi-factor experiments in a large experimental region where the underlying model is unknown. These problems needs space filling designs. The uniform experimental design seeks its design points to be uniformly scattered on the experimental domain and is one kind of space filling designs that can be used for computer experiments and also for industrial experiments when the underlying model is unknown. In this paper we shall introduce the theory and method of the uniform design and related data analysis and modelling methods. Applications of the uniform design to industry and other areas are discussed.
VIRTUAL EXPERIMENTAL DESIGN OPTIMIZATION ON CABLE-DRIVE GLASS GUIDANCE SYSTEM
Authors: LIN CHUN-LIANG
Published: December 2002

This paper focuses on utilizing CAE models, DOE, and RSM to conduct a virtual experimental analysis and design on glass guidance system. The methodologies and critical design parameters are presented.
VEHICLE HIGH MILEAGE POWERTRAIN MOUNT DEGRADATION ANALYSIS
Authors: KUO E. Y.
Published: December 2002

Vehicle high mileage warranty issues associated with powertrain mounts are one of the major concerns in vehicle design for long-term customer satisfaction. The present paper is concerned with a root cause understanding of high mileage degradation mechanisms of hydraulic engine mounts. Engine mount stiffness degradation characteristics are studied using laboratory test data. The correlation between the number of powertrain mount related warranty claims and mean temperatures of different geographic areas in the United States is presented. The effects of underhood thermal management design on mount temperature and strategies for improving high mileage mount degradation are discussed.
SOFTWARE ENGINEERING IN AN SEI LEVEL-5 ORGANIZATION
Authors: TWAITES GREG , SIBILLA MICHELLE L.
Published: December 2002

Developing and delivering quality software in a timely fashion has proven to be a difficult goal to obtain. Defining a thorough and effective software development process lays the foundation for successful projects. The Software Engineering Institute's (SEI) Capability Maturity Model (CMM) defines the framework for such a process. This paper examines the implementation of an SEI Level 5 process within the Communication Systems Division at General Dynamics Decision Systems. A brief review of the CMM is presented followed by an overview of the organization. Examples of the organizations software development process are cited.
MODEL SELECTION FOR ANALYSIS OF UNIFORM DESIGN AND COMPUTER EXPERIMENT
Authors: LI RUNZE
Published: December 2002

In this paper, a new variable selection procedure is introduced for the analysis of uniform design and computer experiment. The new procedure is distinguished from the traditional ones in such a way that it deletes insignificant variables and estimates the coefficients of significant variables simultaneously. The new procedure has an oracle property (Fan and Li8). It is better than the best subset variable selection in terms of computational cost and model stability. It is superior to the stepwise regression because it does not ignore stochastic errors during the course of selecting variables. The proposed procedure is illustrated by two examples, one is a typical example of uniform design, and the other one is a classical example for computer experiment.
EXTERNAL NOISE AND FRONT PROPAGATION IN REACTION-TRANSPORT SYSTEMS WITH INERTIA: THE MEAN SPEED OF FISHER WAVES
Authors: HORSTHEMKE WERNER
Published: December 2002

We review the effect of spatiotemporal noise, white in time and colored in space, on front propagation in systems of reacting and dispersing particles, where the particle motion displays inertia or persistence. We discuss the three main approaches that have been developed to describe transport with inertia, namely hyperbolic reaction-diffusion equations, reaction-Cattaneo systems or reaction-telegraph equations, and reaction random walks. We focus on the mean speed of Fisher waves in these systems and study in particular reaction random walks, which are the most natural generalization of reaction-diffusion equations. Hyperbolic reaction-diffusion equations account for inertia in the transport process in an ad hoc way, whereas the other reaction-transport systems have a proper macroscopic or microscopic foundation. For the former, external noise affects neither the mean wave speed nor the region in parameter space for which Fisher waves exist. For the latter, external noise increases the mean wave speed of Fisher waves and decreases the upper limit for the characteristic time of the transport process, below which propagating fronts exist.
Association analysis of monoamine oxidase A and attention deficit hyperactivity disorder
Authors: Lawson Deborah C. , Turic Darko , Langley Kate , Pay Helen M. , Govan Catherine F. , Norton Nadine , Hamshere Marian L. , Owen Michael J. , O'Donovan Michael C. , Thapar Anita
Published: December 2002

Attention deficit hyperactivity disorder (ADHD) is a highly heritable disorder. Although the causes of ADHD are unknown, dopaminergic, serotonergic and nor‐adrenergic pathways have been strongly implicated. Monoamine Oxidase A (MAOA) is involved in the degradation of all three of these neurotransmitters and therefore has been suggested as a strong candidate gene for ADHD. Animal and human studies have implicated MAOA and 5‐HT in impulsive and aggressive behavior. We therefore additionally postulated that MAOA might be associated with a subtype of ADHD where aggressive and impulsive features are especially prominent. We have tested this hypothesis by genotyping two polymorphisms (the 30‐bp VNTR in the promoter and the Fnu4HI 941T→G) in MAOA that are associated with altered MAOA function. Our sample consisted of 171 British Caucasian children 6–16 years of age fulfilling DSM‐III R, DSM‐IV or ICD‐10 criteria for ADHD/Hyperkinetic Disorder. Using case control analysis and then the TDT, no association was found between these two MAOA polymorphisms and ADHD. Case control analysis of the VNTR showed an association with a subgroup of children with comorbid conduct problems (OR = 2.0, 95% CI = 1.09, 3.5), and TDT analysis indicated a statistical trend toward association. Our findings highlight the importance of phenotype definition and the need for the MAOA VNTR to be further examined. © 2003 Wiley‐Liss, Inc.
Polymorphisms of dopamine receptors and tardive dyskinesia among Chinese patients with schizophrenia
Authors: Chong Siow‐Ann , Tan Ene‐Choo , Tan Chay Hoon , Mythily  , Chan Yiong Huak
Published: December 2002

The putative role of dopamine in the pathophysiology of tardive dyskinesia (TD) makes the genes coding for dopamine receptors the appropriate candidates for study. We investigate the association of the polymorphism of the Ser311Cys and Ser9Gly of the dopamine D2 (DRD2) and D3 receptor (DRD3) genes respectively with TD in Chinese patients with schizophrenia. In a case‐control study, 117 Chinese patients with TD were compared to 200 patients without TD. Patients were diagnosed to have schizophrenia according to DSM‐IV criteria. Dyskinesia was assessed by the Abnormal Involuntary Movement Scale (AIMS), whereas extrapyramidal side‐effects (EPSE) were assessed by the Simpson‐Angus Rating Scale. Genotype groups were comparable in age, gender, duration of illness, daily neuroleptic and benzodiazepine dose as well as the mean scores for EPSE. We failed to find an association between the polymorphism of the DRD2 gene with TD but found an increased risk of developing TD among those with D3 serine/serine genotype. Our results did not indicate that the D2 genotype has a role in the pathophysiology of TD in Chinese patients with schizophrenia. The association of TD with the serine/serine genotype of the DRD3 may be an epiphenomenon of patients with a subtype of schizophrenia who had more exposure to neuroleptics. © 2003 Wiley‐Liss, Inc.
Genetic linkage and association between chromosome 1q and working memory function in schizophrenia
Authors: Gasperoni Timothy L. , Ekelund Jesper , Huttunen Matti , Palmer Christina G.S. , Tuulio‐Henriksson Annamari , Lönnqvist Jouko , Kaprio Jaakko , Peltonen Leena , Cannon Tyrone D.
Published: December 2002

Schizophrenia is substantially heritable, but specific susceptibility genes remain to be identified. Progress in this endeavor has been hindered by non‐Mendelian transmission patterns, probable genetic heterogeneity, and an inability to detect premorbid and nonpenetrant carriers of predisposing genes. To circumvent these complexities, this study employed quantitative measures of liability, or “endophenotypes,” within a sample of twins discordant for schizophrenia, drawn from the relatively genetically isolated population of Finland. A region on the distal portion of chromosome 1 has shown evidence for linkage to schizophrenia in two prior studies using Finnish patient samples. To elucidate further the nature and location of this potential susceptibility gene, linkage and association analyses were carried out across the chromosome 1 region of interest using quantitative neuropsychological measures of liability. Analyses with a composite measure of liability yielded suggestive evidence for linkage at marker D1S2833 (P = 0.04). Follow‐up analyses of the individual trait measures showed that the Visual Span subtest of the Wechsler Memory Scale (WMS), an indicator of spatial working memory function, was uniquely sensitive to marker D1S2833 (P = 0.007). Association analysis confirmed that allelic variation in D1S2833 is associated with variation in spatial working memory performance as measured by the Visual Span subtest (P = 0.003), the significance of which was confirmed in an analysis of 10,000 Monte Carlo permutations. These data support the utility of this approach and provide evidence for a gene affecting spatial working memory function in schizophrenia patients and their unaffected co‐twins. © 2002 Wiley‐Liss, Inc.
Generalized Cognitive Impairment in Male Adolescents With Schizotypal Personality Disorder
Authors: Weiser M. , Noy S. , Kaplan Z. , Reichenberg A. , Yazvitsky R. , Nahon D. , Grotto Itamar , Knobler H.Y.
Published: December 2002

Schizotypal Personality Disorder (SPD) shares common genetic and biological substrates with schizophrenia, and patients with SPD have been reported to suffer both from specific cognitive impairments, and from a generalized cognitive dysfunction, similar to those found in schizophrenia. The aim of this cross‐sectional, population‐based study was to assess general cognitive functioning in adolescents with SPD. The Israeli Draft Board systematically assesses cognitive functioning and administers psychiatric screening in all 16–17‐year‐old males in the population. Of 341,511 males assessed, the cognitive test scores of adolescents with SPD (N = 326) were retrieved, and compared to the scores of adolescents diagnosed as suffering from schizophrenia (N = 901), and adolescents with no neurological or psychiatric diagnosis (controls, N = 293,820). Male adolescents with SPD or with schizophrenia scored lower on all measures compared to healthy individuals (effect sizes ranging from 0.6–0.88, all P < 0.001). The SPD patients scored significantly higher than the schizophrenia patients on the sub‐tests of similarities and Ravens Progressive Matrices, tests that reflect abstract reasoning. On the sub‐tests of arithmetic and instruction comprehension, tests that rely on concentration, SPD and schizophrenia patients' scores did not differ significantly from each other. These results might be interpreted to imply that a generalized cognitive impairment, in the presence of schizotypal personality traits and in the absence of psychosis, might be conceptualized as being the core of the schizotaxia syndrome. The greater impairment in abstract reasoning in the schizophrenia patients might be correlated with the psychotic symptoms that differentiate schizophrenia from SPD. © 2003 Wiley‐Liss, Inc.
Synthesis and characterization of polyacrylamide‐grafted chitosan hydrogel microspheres for the controlled release of indomethacin
Authors: Kumbar Sangamesh G. , Soppimath Kumaresh S. , Aminabhavi Tejraj M.
Published: December 2002

Microspheres of polyacrylamide‐grafted‐chitosan crosslinked with glutaraldehyde were prepared and used to encapsulate indomethacin, a nonsteroidal anti‐inflammatory drug. The microspheres were produced by the water/oil emulsion technique and encapsulation of indomethacin was carried out before crosslinking of the matrix. The extent of crosslinking was analyzed by Fourier transform infrared spectroscopy and differential scanning calorimetry. Microspheres were characterized for drug‐entrapment efficiency, particle size, and water transport into the polymeric matrix as well as for drug‐release kinetics. Scanning electron microscopy confirmed the spherical nature and surface morphology of the particles with a mean particle size of 525 μm. Dynamic swelling experiments suggested that, with an increase in crosslinking, the transport mechanism changed from Fickian to non‐Fickian. The release of indomethacin depends upon the crosslinking of the network and also on the amount of drug loading. This was further supported by the calculation of drug‐diffusion coefficients using the initial time approximation. The drug release in all the formulations followed a non‐Fickian trend and the diffusion was relaxation‐controlled. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1525–1536, 2003
Conducting polyaniline nanofiber networks prepared by the doping induction of camphor sulfonic acid
Authors: He Chang , Tan Yiwei , Li Yongfang
Published: December 2002

Branched nanofibers of conducting polyaniline (PANI) buried in the crystals of camphor sulfonic acid (CSA) were prepared from an m‐cresol solution of PANI and excessive CSA. After the excessive CSA was dissolved through ultrasonication in deionized water, networks of PANI nanofibers with spherical nodes, nanoparticles, leaf‐vein‐shaped nanofibers, and so forth were obtained according to the strength of the ultrasonic treatment. The X‐ray diffraction patterns of the CSA‐doped PANI showed high crystallinity. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1537–1540, 2003
Flow cytometric‐based isolation of nucleated erythroid cells during maturation: An approach to cell surface antigen studies
Authors: Fornas Oscar , Domingo Joan Carles , Marin Pedro , Petriz Jordi
Published: December 2002

Nucleated red blood cells (NRBCs) are involved in normal physiologic processes, as well as in several malignancies. They are usually counted manually under the microscope. However, blood sample manipulation may be a source of variability and manual counting is imprecise, time‐consuming, and subjective. To improve identification of CD45‐negative cells, we used a flow cytometry technique that avoids the addition of lysing reagents and stains viable cell nuclei. We applied this method for counting and isolating NRBC subpopulations in whole blood samples, using DNA/RNA viable staining to discriminate nonnucleated erythroid cells and debris. NRBC counts gave 197.95 cells per mm3 in mobilized peripheral blood samples (1.00%, n = 20), 3,897.59 cells per mm3 in leukapheresis products (3.08%, n = 20), and 765.21 cells per mm3 in cord blood samples (6.09%, n = 20). Normal bone marrow counts were 5,449.42 cells per mm3 (11.76%, n = 20). Scatter profiles showed three distinct populations, from early to late‐stage erythroblasts, consisting of erythroblasts, orthochromatic erythroblasts, and ejected nuclei, as confirmed by Wright‐Giemsa staining. In addition, flow cytometry immunophenotyping showed that glycophorin A was expressed dimly on NRBCs during maturation. These findings point to the feasibility of live NRBCs studies, which offer great potential for a wide range of disciplines. Cytometry (Clin. Cytometry) 50:305–312, 2002. © 2002 Wiley‐Liss, Inc.
9‐Aminoacridine: An efficient reagent to improve human and plant chromosome banding patterns and to standardize chromosome image analysis
Authors: Muravenko Olga V. , Amosova Alexandra V. , Samatadze Tatiana E. , Popov Konstantin V. , Poletaev Andrei I. , Zelenin Alexander V.
Published: December 2002

Background

Successful automated chromosome analysis requires the development of new techniques to increase and standardize chromosome length and improve banding patterns.

Methods

Human and plant cells were pretreated with the DNA intercalator 9‐aminoacridine (9‐AMA), and chromosomes were stained with GTG and aceto‐orcein banding techniques and investigated by an image analysis system.

Results

The human optimal chromosome spreads with the 850 G‐band resolution level, suitable for image analysis, were obtained by 9‐AMA pretreatment for 1 h at a final concentration of 0.5–1 μg/ml, as compared with 600–700 bands after ethidium bromide treatment and about 400 bands without pretreatment. The best results for plant chromosomes were obtained after pretreatment with 1–2 μg/ml of 9‐AMA for 12–24 h. The chromosomes elongated approximately 1.5‐fold, and the resolution of chromosome banding patterns increased, reaching approximately 140 bands per haploid set in the case of camomile.

Conclusions

9‐AMA is an efficient reagent for the standardization and increasing the resolution of chromosome banding patterns in human and plant chromosomes. It is extremely important for chromosome investigation in small plants. Cytometry Part A 51A:52–57, 2003. © 2002 Wiley‐Liss, Inc.
Acute toxicity of all‐trans‐retinoic acid loaded poly(L‐lactide)/poly(ethylene glycol)‐poly(L‐lactide) microspheres in mice
Authors: Choi Yongdoo , Lee Chulkyu , Kim Sang Yoon , Kim Sun Hee , Moon Hyun Tae , Park Tae Gwan , Byun Youngro
Published: December 2002

Previously, poly(L‐lactide) microspheres containing retinoic acid (RA) had been prepared for parenteral administration in order to overcome “acute retinoic acid resistance.” In this study, acute toxicities of RA‐loaded microspheres were investigated in mice after the microspheres were injected intramuscularly. The maximum dose of RA in the microspheres was determined by considering both the injection volume and dispersion of microspheres in the vehicle media, and the dose levels were determined to be 0, 90, 180, and 360 mg RA/kg. Mice were carefully observed for any clinical signs for 14 days, and gross observation of the organs was performed at 14 days. When a dose of 90 mg RA/kg was administered, no severe toxicities were observed; however, with the administration of 180 and 360 mg RA/kg, abnormal appearances of organs, such as discolor, atrophy, hemorrhage, etc., were observed. There were no mortalities or bone fractures observed at any of the doses. In our previous study of cancer treatment using the RA‐loaded microspheres, the growth of head and neck carcinoma in athymic nude mice was successfully inhibited at the dose of 100 mg RA/kg. It was concluded that a dose of approximately 90 mg RA/kg of the RA‐loaded microspheres would be most desirable for cancer therapy. Drug Dev. Res. 57:134–139, 2002. © 2002 Wiley‐Liss, Inc.
Changing the environment in eating disorders: working with carers/families to improve motivation and facilitate change
Authors: Treasure Janet , Gavan Kay , Todd Gill , Schmidt Ulrike
Published: December 2002

The aim of this paper is to consider the needs of carers of people with adult anorexia nervosa both from a theoretical and practical basis. Families have been successfully involved in the management of adolescent anorexia nervosa but it is uncertain how best to work with the families of people who have a more chronic course of illness. The management of severe, persistent, eating disorders has benefited from the application of theory derived from models of health behaviour. These theory‐driven approaches can also be applied to work with carers. We argue that illness perception theory can also have potential utility in understanding the needs and difficulties faced by carers. In this paper we briefly review these theoretical models and consider how they can be applied to carers of people with chronic anorexia nervosa. Finally we discuss how these theory driven approaches can guide the development of interventions for use with carers. Copyright © 2002 John Wiley & Sons, Ltd and Eating Disorders Association.
Early Holocene Paleoindian deposits at Nall Playa, Oklahoma Panhandle, U.S.A.
Authors: LaBelle Jason M. , Holliday Vance T. , Meltzer David J.
Published: December 2002

Fieldwork conducted at the Nall North locale and the adjacent playa documents buried Paleoindian deposits and a stratigraphic sequence dating back to the late Pleistocene. Cultural debris recovered from the surface of Nall North includes bone, tools, and lithic flake debris. Two buried paleosols at the locale date to the early Holocene and hold high potential for Paleoindian materials. The Baker paleosol, a stabilized surface above the shoreline of the adjacent playa lake, dated between ca. 6870 and 7740 yr B.P., contains a rich cultural component of tools, flakes, and bone, and represents a potential surface for Angostura and Allen/Frederick artifacts. Located below the Baker soil is the Nall soil (dated to ca. 9650 yr B.P.) that probably represents a marsh facies of the playa fill. The Nall soil represents a potential surface for Plainview/Goshen‐age artifacts, although excavations thus far have recovered no cultural debris. In the playa adjacent to the Nall North locality, a sequence dating between ca. 12,960 and 5310 yr B.P. documents localized spring flow into the playa during the late Pleistocene, followed by several thousand years of playa muds during the early Holocene, and the eventual drying of the playa in the middle Holocene. © 2003 Wiley Periodicals, Inc.
Digging for the color of life: Paleoindian red ochre mining at the Powars II site, Platte County, Wyoming, U.S.A.
Authors: Stafford Michael D. , Frison George C. , Stanford Dennis , Zeimans George
Published: December 2002

The Powars II site, 48PL330, located near Sunrise, Wyoming, is a significant Paleoindian site in the Hartville Uplift area of eastern Wyoming. Intensive red ochre mining took place at Powars II, as indicated by Paleoindian materials in direct association with a natural hematite deposit. Projectile points ranging in age from Clovis to Late Paleoindian have been recovered, as well as stone and bone tools, shell and bone beads, and several pieces of incised bone. It is argued that the Powars II assemblage reflects a two‐part cultural manifestation: a technological component resulting from the process of mining and processing ochre, and an ideological component derived from emic beliefs about the ochre source itself. © 2003 Wiley Periodicals, Inc.
Eolian and soil stratigraphy at a Paleoindian site along the South Platte River valley, Nebraska, U.S.A.
Authors: May David W. , Holen Steven R.
Published: December 2002

Eolian and soil stratigraphy and radiocarbon ages of soil humates were used to reconstruct landscape evolution at a site (25KH67) in western Nebraska along the South Platte River. The site is on the bluff of a short, deeply incised, dune‐blocked tributary to the South Platte. The Paleoindian component is in the lower part of the Brady Soil. The age of the lower Brady Soil where cultural material was recovered is 10,360 yr B.P., and the age of the upper Brady Soil is 6090 yr B.P. The Brady Soil formed over a longer interval at site 25KH67 than at other upland localities in southern Nebraska and Kansas. Three episodes of eolian deposition occurred after 6090 yr B.P. Discovery of additional Paleoindian sites along the South Platte River valley and across the central Great Plains will be hampered by Holocene eolian deposits that blanket the Brady Soil. © 2003 Wiley Periodicals, Inc.
Geoarchaeological investigations at the Winger site: A Late Paleoindian bison bonebed in southwestern Kansas, U.S.A.
Authors: Mandel Rolfe D. , Hofman Jack L.
Published: December 2002

The Winger site is a deeply buried Late Paleoindian bison bonebed in a playa basin on the High Plains of midcontinental North America. The site is one of few stratified, Late Paleoindian bison kills recorded in the region. The bonebed is exposed in the bank of an intermittent stream that cut into the edge of the playa basin. Avocational archaeologists excavated a small portion of the exposed bonebed in the early 1970s and reported flakes in association with the skeletal remains. Limited reinvestigations of the site were undertaken in 2001, and a month‐long excavation was conducted in 2002 to assess the stratigraphy, geochronology, and archaeology. The bonebed is 35 m long in a buried soil developed in fine‐grained basin fill overlain by early Holocene alluvium (arroyo fill). Recent alluvium overlies a soil developed in the early Holocene alluvium, and modern deposits of eolian sand 2 m to < 35 cm thick mantle the site area. Artifacts found at the site include two Allen points and a flake tool discovered in the bone bed, and a biface and Allen point fragment in disturbed bonebed deposits. Excavation of 9 m2 of the bone bed revealed some fully articulated skeletons, and taphonomic observations suggest some of the bison collapsed while standing in a playa or pond margin setting. The remains of at least six bison are represented in the excavated sample from 2002, but many more animals are represented in the bonebed. A 14C age of ca. 9000 yr B.P. was determined on collagen from bison rib fragments. This age is consistent with the diagnostic artifacts found at Winger. © 2003 Wiley Periodicals, Inc.
Structural and dynamical analysis of the hydration of the Alzheimer's β‐amyloid peptide
Authors: Massi Francesca , Straub John E.
Published: December 2002

An analysis of the water molecules in the first solvation shell obtained from the molecular dynamics simulation of the amyloid β(10‐35)NH2 peptide and the amyloid β(10‐35)NH2E22Q “Dutch” mutant peptide is presented. The structure, energetics, and dynamics of water in the hydration shell have been investigated using a variety of measures, including the hydrogen bond network, the water residence times for all the peptide residues, the diffusion constant, experimentally determined HN amide proton exchange, and the transition probabilities for water to move from one residue to another or into the bulk. The results of the study indicate that: (1) the water molecules at the peptide‐solvent interface are organized in an ordered structure similar for the two peptide systems but different from that of the bulk, (2) the peptide structure inhibits diffusion perpendicular to the peptide surface by a factor of 3 to 5 relative to diffusion parallel to the peptide surface, which is comparable to diffusion of bulk water, (3) water in the first solvation shell shows dynamical relaxation on fast (1–2 ps) and slow (10–40 ps) time scales, (4) a novel solvent relaxation master equation is shown to capture the details of the fast relaxation of water in the peptide's first solvation shell, (5) the interaction between the peptide and the solvent is stronger in the wild type than in the E22Q mutant peptide, in agreement with earlier results obtained from computer simulations [Massi, F.; Straub, J. E. Biophys J 2001, 81, 697] correlated with the observed enhanced activity of the E22Q mutant peptide. © 2002 Wiley Periodicals, Inc. J Comput Chem 24: 143–153, 2003
Fast, efficient generation of high‐quality atomic charges. AM1‐BCC model: II. Parameterization and validation
Authors: Jakalian Araz , Jack David B. , Bayly Christopher I.
Published: December 2002

We present the first global parameterization and validation of a novel charge model, called AM1‐BCC, which quickly and efficiently generates high‐quality atomic charges for computer simulations of organic molecules in polar media. The goal of the charge model is to produce atomic charges that emulate the HF/6‐31G* electrostatic potential (ESP) of a molecule. Underlying electronic structure features, including formal charge and electron delocalization, are first captured by AM1 population charges; simple additive bond charge corrections (BCCs) are then applied to these AM1 atomic charges to produce the AM1‐BCC charges. The parameterization of BCCs was carried out by fitting to the HF/6‐31G* ESP of a training set of >2700 molecules. Most organic functional groups and their combinations were sampled, as well as an extensive variety of cyclic and fused bicyclic heteroaryl systems. The resulting BCC parameters allow the AM1‐BCC charging scheme to handle virtually all types of organic compounds listed in The Merck Index and the NCI Database. Validation of the model was done through comparisons of hydrogen‐bonded dimer energies and relative free energies of solvation using AM1‐BCC charges in conjunction with the 1994 Cornell et al. forcefield for AMBER.13 Homo‐ and hetero‐dimer hydrogen‐bond energies of a diverse set of organic molecules were reproduced to within 0.95 kcal/mol RMS deviation from the ab initio values, and for DNA dimers the energies were within 0.9 kcal/mol RMS deviation from ab initio values. The calculated relative free energies of solvation for a diverse set of monofunctional isosteres were reproduced to within 0.69 kcal/mol of experiment. In all these validation tests, AMBER with the AM1‐BCC charge model maintained a correlation coefficient above 0.96. Thus, the parameters presented here for use with the AM1‐BCC method present a fast, accurate, and robust alternative to HF/6‐31G* ESP‐fit charges for general use with the AMBER force field in computer simulations involving organic small molecules. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 1623–1641, 2002
Theoretical study of sheets formed by β‐peptides
Authors: Lin Jin‐Qiu , Luo Shi‐Wei , Wu Yun‐Dong
Published: December 2002

Structural and thermodynamic features of the sheets formed by β‐peptides have been studied by quantum mechanics calculations using peptide models. Calculations using dipeptide models indicate that the intrinsic hydrogen bond strength is great for both parallel and antiparallel sheets and that it is little affected by proper substituents. Heterochiral‐β2,3‐peptides have much stronger sheet‐forming propensity than other types of peptides because their favored backbone conformation is ideal for sheet formation. A planar or ideally pleated strand has a curved geometry, which is unfavorable for the formation of sheets. Thus, sheets have to adopt twisted geometries. There is a large cooperativity in the formation of the hydrogen bond network in the sheets of β‐peptides in the perpendicular direction due to long‐range electrostatic attractions because all carbonyl groups are roughly in the same direction, in contrast to the situation in β‐sheets of α‐peptides. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 1551–1558, 2002
Computational study of epoxy‐amine reactions
Authors: Okumoto Satoshi , Yamabe Shinichi
Published: December 2002

Density functional theory calculations were carried out for the title reactions. Ethylene oxide and methylamine were adopted as reactants. Amine clusters (dimer, trimer, tetramer, and pentamer) were considered, because the combination of one oxide and one amine molecule gave a large activation energy. An amine tetramer was found to react favorably with the oxide via various zwitterionic intermediates. A back‐side SN2 nucleophilic attack of one amine and the subsequent proton relay up to the front side provide a stabilized reaction field. The amine‐alcohol mixed reactant may react readily with the oxide, because the alcoholic OH group is in contact with the oxide oxygen with the strong hydrogen‐bond stabilization. © 2002 Wiley Periodicals, Inc. J Comput Chem 24: 244–253, 2003
Hydride transfer catalyzed by xylose isomerase: Mechanism and quantum effects
Authors: Garcia‐Viloca Mireia , Alhambra Cristóbal , Truhlar Donald G. , Gao Jiali
Published: December 2002

We have applied molecular dynamics umbrella‐sampling simulation and ensemble‐averaged variational transition state theory with multidimensional tunneling (EA‐VTST/MT) to calculate the reaction rate of xylose‐to‐ xylulose isomerization catalyzed by xylose isomerase in the presence of two Mg2+ ions. The calculations include determination of the free energy of activation profile and ensemble averaging in the transmission coefficient. The potential energy function is approximated by a combined QM/MM/SVB method involving PM3 for the quantum mechanical (QM) subsystem, CHARMM22 and TIP3P for the molecular mechanical (MM) environment, and a simple valence bond (SVB) local function of two bond distances for the hydride transfer reaction. The simulation confirms the essential features of a mechanism postulated on the basis of kinetics and X‐ray data by Whitlow et al. (Whitlow, M.; Howard, A. J.; Finzel, B. C.; Poulos, T. L.; Winborne, E.; Gilliland, G. L. Proteins 1991, 9, 153) and Ringe, Petsko, and coworkers (Labie, A.; Allen, K.‐N.; Petsko, G. A.; Ringe, D. Biochemistry 1994, 33, 5469). This mechanism involves a rate‐determining 1,2‐hydride shift with prior and post proton transfers. Inclusion of quantum mechanical vibrational energy is important for computing the free energy of activation, and quantum mechanical tunneling effects are essential for computing kinetic isotope effects (KIEs). It is found that 85% of the reaction proceeds by tunneling and 15% by overbarrier events. The computed KIE for the ratio of hydride to deuteride transfer is in good agreement with the experimental results. The molecular dynamics simulations reveal that proton and hydride transfer reactions are assisted by breathing motions of the mobile Mg2+ ion in the active site, providing evidence for concerted motion of Mg2+ during the hydride transfer step. © 2002 Wiley Periodicals, Inc. J Comput Chem 24: 177–190, 2003