bluuebunny/crossref_metadata_2025 huggingface dataset:
Laser Z-pinch dipole-target experiments to simulate space physics acceleration processes
Authors: Horton W. , Chiu C.
Published: April 2004

Laboratory experiments using a plasma wind generated by laser–target interaction are proposed and analyzed to investigate the creation of a shock in front of the magnetosphere and the dynamo mechanism. Magnetic dipoles are placed in the plasma wind and measurements of the electron fluxes bombarding the spheres surrounding the dipoles are to be recorded. The experiments are to be analyzed with the methods used in theoretical simulation of the solar-wind-driven magnetosphere interactions. The proposed experiments, which involve measurements on the creation of the shock front due to the impact of the supersonic plasma wind on the magnetosphere, and the subsequent generation of energetic electrons, are thought to be relevant to understanding the acceleration mechanisms at work in shock-driven magnetic dipole confined plasma.
Forecast of auroral activity
Authors: Lui A. T. Y.
Published: April 2004

A new technique is developed to predict auroral activity based on a sample of over 9000 auroral sites identified in global auroral images obtained by an ultraviolet imager on the NASA Polar satellite during a 6-month period. Four attributes of auroral activity sites are utilized in forecasting, namely, the area, the power, and the rates of change in area and power. This new technique is quite accurate, as indicated by the high true skill scores for forecasting three different levels of auroral dissipation during the activity lifetime. The corresponding advanced warning time ranges from 22 to 79 min from low to high dissipation levels.
A new approach to parameter identification for nonlinear systems
Authors: Tomás-Rodrı́guez M. , Banks S. P. , Hätönen J. J. , Alleyne H. St. C. K.
Published: April 2004

In this paper a new approach to the problem of parameter identification for logistic-type systems is introduced in order to identify the qualitative characteristics of some given nonlinear systems. The method is applied to problems of importance in physics-plasma waves measured by two closely spaced satellites and the Korteweg–de Vries equation, and successful parameters estimation is demonstrated. The technique is based in a sequence of approximations which will produce a sequence of linear time-varying systems whose solutions converge to the solution of the original nonlinear system.
Response to “Comment on ‘Dynamics of zonal flow saturation in strong collisionless drift wave turbulence’ ” [Phys. Plasmas 11, 1744 (2004)]
Authors: Kim Eun-jin , Diamond P. H.
Published: April 2004

The Comment of Krommes is addressed. It is shown that all of the substantive claims therein are incorrect.
Transient shear instability of differentially rotating and self-gravitating dusty plasma
Authors: Rogava Andria D. , Poedts Stefaan , Osmanov Zaza
Published: April 2004

Recently it was found [Poedts et al., Phys. Plasmas 7, 3204 (2000)] that dusty plasma flows host nonperiodic modes—shear-dust-acoustic (SDA) vortices. These modes, interlaced with dust-acoustic (DA) waves, are able to exchange energy with the ambient flow. In this paper it is studied how these processes evolve in differentially rotating and self-gravitating flows of dusty plasmas. It is found that the presence of the self-gravity and of Coriolis forces makes both SDA vortices and DA waves transiently unstable. It is argued that the transient shear instability could be important for the formation of the fine structure of planetary rings, for the dynamics of charged dust masses and transition to dust-acoustic turbulence in galactic gaseous disks.
Fully adaptive propagation of the quantum-classical Liouville equation
Authors: Horenko Illia , Weiser Martin , Schmidt Burkhard , Schütte Christof
Published: April 2004

In mixed quantum-classical molecular dynamics few but important degrees of freedom of a dynamical system are modeled quantum-mechanically while the remaining ones are treated within the classical approximation. Rothe methods established in the theory of partial differential equations are used to control both temporal and spatial discretization errors on grounds of a global tolerance criterion. The TRAIL (trapezoidal rule for adaptive integration of Liouville dynamics) scheme [I. Horenko and M. Weiser, J. Comput. Chem. 24, 1921 (2003)] has been extended to account for nonadiabatic effects in molecular dynamics described by the quantum-classical Liouville equation. In the context of particle methods, the quality of the spatial approximation of the phase-space distributions is maximized while the numerical condition of the least-squares problem for the parameters of particles is minimized. The resulting dynamical scheme is based on a simultaneous propagation of moving particles (Gaussian and Dirac deltalike trajectories) in phase space employing a fully adaptive strategy to upgrade Dirac to Gaussian particles and, vice versa, downgrading Gaussians to Dirac-type trajectories. This allows for the combination of Monte-Carlo-based strategies for the sampling of densities and coherences in multidimensional problems with deterministic treatment of nonadiabatic effects. Numerical examples demonstrate the application of the method to spin-boson systems in different dimensionality. Nonadiabatic effects occurring at conical intersections are treated in the diabatic representation. By decreasing the global tolerance, the numerical solution obtained from the TRAIL scheme are shown to converge towards exact results.
The Fisher–Shannon information plane, an electron correlation tool
Authors: Romera E. , Dehesa J. S.
Published: April 2004

A new correlation measure, the product of the Shannon entropy power and the Fisher information of the electron density, is introduced by analyzing the Fisher–Shannon information plane of some two-electron systems (He-like ions, Hooke’s atoms). The uncertainty and scaling properties of this information product are pointed out. In addition, the Fisher and Shannon measures of a finite many-electron system are shown to be bounded by the corresponding single-electron measures and the number of electrons of the system.
Advances in point-contact spectroscopy: two-band superconductor MgB2 (Review)
Authors: Yanson I. K. , Naidyuk Yu. G.
Published: April 2004

Analysis of the point-contact spectroscopy (PCS) data on the dramatic new high-Tc superconductor magnesium diboride MgB2 reveals quite different behavior of two disconnected σ and π electronic bands, deriving from their anisotropy, different dimensionality, and electron–phonon interaction. PCS allows direct registration of both the superconducting gaps and electron–phonon interaction spectral function of the two-dimensional σ and three-dimensional π band, establishing the correlation between the gap value and the intensity of the high-Tc driving force—the E2g boron vibrational mode. PCS data on some nonsuperconducting transition-metal diborides are surveyed for comparison.
Temperature dependence of the conductivity, thermopower, and heat capacity of TlCoS2
Authors: Kerimova E. M. , Mustafaeva S. N. , Aldjanov M. A. , Jabbarly A. I.
Published: April 2004

The temperature dependence of the conductivity and thermopower of TlCoS2 is studied over a wide range of temperatures (77–400 K). It is found that TlCoS2 is characterized by p-type conductivity in the temperature interval 77–225 K and that an inversion of the sign of the thermopower occurs at 225 K. The heat capacity of the ferromagnetic compound TlCoS2 is also measured in the temperature interval 55–300 K. It is shown that the behavior of the magnetic part of the heat capacity of TlCoS2 is typical of a quasi-low-dimensional magnet. The experimental data on the temperature dependence of the heat capacity are used to calculate the thermodynamic parameters of TlCoS2: the changes in entropy and enthalpy.
Molecular alignment in a liquid induced by a nonresonant laser field: Molecular dynamics simulation
Authors: Ohkubo Jun , Kato Tsuyoshi , Kono Hirohiko , Fujimura Yuichi
Published: April 2004

We carried out molecular dynamics (MD) simulations for a dilute aqueous solution of pyrimidine in order to investigate the mechanisms of field-induced molecular alignment in a liquid phase. An anisotopically polarizable molecule can be aligned in a liquid phase by the interaction with a nonresonant intense laser field. We derived the effective forces induced by a nonresonant field on the basis of the concept of the average of the total potential over one optical cycle. The results of MD simulations show that a pyrimidine molecule is aligned in an aqueous solution by a linearly polarized field of light intensity I∼1013 W/cm2 and wavelength λ=800 nm. The temporal behavior of field-induced alignment is adequately reproduced by the solution of the Fokker–Planck equation for a model system in which environmental fluctuations are represented by Gaussian white noise. From this analysis, we have revealed that the time required for alignment in a liquid phase is in the order of the reciprocals of rotational diffusion coefficients of a solute molecule. The degree of alignment is determined by the anisotropy of the polarizability of a molecule, light intensity, and temperature. We also discuss differences between the mechanisms of optical alignment in a gas phase and a liquid phase.
Polymer–particle mixtures: Depletion and packing effects
Authors: Doxastakis M. , Chen Y-L. , Guzmán O. , de Pablo J. J.
Published: April 2004

The structure of polymers in the vicinity of spherical colloids is investigated by Monte Carlo simulations and integral equation theory. Polymers are represented by a simple bead–spring model; only repulsive Lennard-Jones interactions are taken into account. Using advanced trial moves that alter chain connectivity, depletion and packing effects are analyzed as a function of chain length and density, both at the bond and the chain level. Chain ends segregate to the colloidal surface and polymer bonds orient parallel to it. In the dilute regime, the polymer chain length governs the range of depletion and has a negligible influence on monomer packing in dense polymer melts. Polymers adopt an ellipsoidal shape, with the larger axis parallel to the surface of the particle, as they approach larger colloids. The dimensions are perturbed within the range of the depletion layer.
Anomalous mixing behavior of polyisobutylene/polypropylene blends: Molecular dynamics simulation study
Authors: Jaramillo Eugenio , Wu David T. , Grest Gary S. , Curro John G.
Published: April 2004

The unusual mixing behavior of polyisobutylene (PIB) with head-to-head (hhPP) and head-to-tail polypropylene (PP) is studied using large-scale molecular dynamics (MD). The heats of mixing and Flory χ parameters were computed from MD simulations of both blends using a united atom model. The χ parameters from the simulations were estimated from the structure factors using the random phase approximation in analogy with neutron scattering (SANS) experiments. MD simulations for syndiotactic hhPP/PIB predicted a lower critical solution temperature with a χ parameter in very good agreement with SANS experiments on the atactic hhPP/PIB blend. MD simulations also predicted that the isotactic PP/PIB blend was immiscible at high molecular weight in qualitative agreement with cloud point measurements on atactic PP/PIB.
Improving interpersonal job skills by applying cross‐cultural training
Authors: Barker S.A.
Published: April 2004

This paper presents an experimental study that examined the effects of cross‐cultural instruction on the interpersonal job skills of students in secondary vocational programs. The findings indicated that students receiving the cross‐cultural instruction had significantly higher generalizable interpersonal relations skills achievement than students not receiving the instruction. It was recommended that cross‐cultural instruction be integrated into vocational and industrial training curriculum, including instructor training. Trainers should assist trainees in associating cultural awareness to their personal and professional success. A model is offered as a guide for developing generalizable interpersonal skills training materials for a diverse workplace. The model defines culture broadly, including gender and age. Examination of cultures within which the trainees are most familiar may assist in the understanding of more diverse differences between ethnic groups.
The role of information and communications technology in transforming marketing theory and practice
Authors: Naudé Pete , Holland Christopher P.
Published: April 2004

Introduces the special issue entitled “The role of information and communications technology in transforming marketing theory and practice”. Outlines the themes discussed in the papers in the issue, which seek to provide insights into how information and communications technology is transforming marketing theory and activities.
The metamorphosis of marketing into an information‐handling problem
Authors: Holland Christopher P. , Naudé Pete
Published: April 2004

There have traditionally been different ways in which to view the marketing task, distinctions that have been drawn to facilitate the level of insight available to managers involved in marketing the firm's offer. A traditional distinction has been between business‐to‐consumer (B2C) and business‐to‐business (B2B) marketing. More recently, much has been written on whether the appropriate perspective of marketing should be transaction‐based or relationship‐driven. This paper argues that a different view is more useful: that the marketing task has moved beyond being transaction‐ or relationship‐driven, and that it can and should increasingly often be viewed as an information‐handling problem. First identifies what are considered to be the main tasks facing a marketing manager, and then interpret how these tasks may be managed in each of the transaction‐, relationship‐, and information‐driven approaches. By using three different case study vignettes, provides evidence of the applicability of these ideas.
The impact of information technology deployment on trust, commitment and value creation in business relationships
Authors: Ryssel Ricky , Ritter Thomas , Georg Gemünden Hans
Published: April 2004

To strengthen their position in today's highly‐competitive and fast‐paced business environment, supplier firms often engage in relationships with their customers. Recent advances in information technology offer new ways of managing inter‐organizational relationships. In this paper, a model conceptualizing the impact of information technology deployment on inter‐organizational buyer‐seller relationships is developed. Using an empirical study of 61 German firms engaged in customer‐supplier relationships, this paper also gives some empirical evidence for the developed framework. With regard to relationship management, intra‐ and inter‐organizational information technology deployment has different effects on relationship atmosphere and on the relationship's value creation. The findings give new insight into the role of information technology in value‐creation in business‐to‐business relationships. Managerial implications and future research questions in this area are also discussed.
Social capital: a building‐block in creating a better global future
Authors: Landman J.P.
Published: April 2004

This article presents a South African's perspective on the possible role of social capital in achieving long‐term sustainable human and economic development in the world. Social capital is defined as the presence of effective human networks and social cohesion, which are manifested in effective institutions and processes where people can co‐operate for mutual advantage. This article postulates that social capital can help societies to achieve internal evolution towards sustainable development in a manner that can resolve the problem of the commons. It proposes that three “tipping points” drive socio‐economic development: open society; economic growth; and creative minorities – including an entrepreneurial class. Social capital provides a supportive environment for these tipping points and, in this case, more is better. Ways to create more social capital are discussed with reference to the sources of social capital. These include the freedom to form networks, anti‐corruption measures, sanctions against transgressors, using the budget as well as the potential contribution of social transformation policies.
Molecular analysis of the major Phytophthora species on cocoa
Authors: Appiah A. A. , Flood J. , Archer S. A. , Bridge P. D.
Published: April 2004

The internally transcribed spacer (ITS) regions of the ribosomal RNA (rRNA) gene cluster of 161 isolates of Phytophthora species involved in pod rot, stem canker and leaf blight of cocoa were analysed to determine inter‐ and intraspecific variation in this disease complex. The species P. palmivora, P. megakarya, P. capsici, P. citrophthora and P. nicotianae could all be clearly distinguished by PCR amplification of the ITS region followed by restriction analysis with HaeIII, HinfI, PvuII and AluI. This method provided a relatively rapid identification procedure for these species, and was able to distinguish isolates that had previously been misidentified by morphological methods. Sequence analysis showed that the four main cocoa‐associated species formed two distinct groups, one comprising P. capsici and P. citrophthora, and the other P. palmivora and P. megakarya. Detailed sequence analysis and comparison with published literature suggested that P. capsici isolates from cocoa may be closely related to P. tropicalis, a species recently described from Cyclamen and Dianthus.
The competence of four thrips species to transmit and replicate four tospoviruses
Authors: Nagata T. , Almeida A. C. L. , Resende R. O. , DeÁvila A. C.
Published: April 2004

The tospoviruses Tomato spotted wilt virus (TSWV), Tomato chlorotic spot virus (TCSV), Groundnut ringspot virus (GRSV) and Chrysanthemum stem necrosis virus (CSNV) are well‐known pathogens on tomato in Brazil. The thrips species Frankliniella occidentalis, F. schultzei, Thrips tabaci and T. palmi were studied for their competence to transmit these tospoviruses. Frankliniella occidentalis transmitted all four tospoviruses with different efficiencies. Frankliniella schultzei transmitted TCSV, GRSV and CSNV. Although F. schultzei has been reported as a vector of TSWV, the F. schultzei population in the present study did not transmit the TSWV isolate used. A population of T. tabaci known to transmit Iris yellow spot virus (onion isolate) did not transmit any of the studied tospoviruses, and nor did T. palmi. Replication of these tospoviruses could be demonstrated by ELISA, not only in the thrips species that could transmit them, but also in those that could not. The results strongly suggest that competence to transmit is regulated not only by the initial amount of virus acquired and replication, but also by possible barriers to virus circulation inside the thrip's body.
Jurassic depositional records and sandstone provenances in Hefei Basin, central China: Implication for Dabie orogenesis
Authors: Li Zhong , Li Renwei , Sun Shu , Wang Qingchen
Published: April 2004

Abstract  Detrital composition and major element geochemistry of Jurassic sandstones in the south Hefei Basin, central China, show their provenance to be the Dabie Mountains, whose tectonic attributes are closely related to continent–island arc complexes. It was found that a provenance change, from recycled orogen signatures and mixed orogenic sandstones to arc orogen, occurs from the lower Middle Jurassic to the Upper Jurassic (the Zhougongshan Formation). Dissected magmatic arc sources were gradually exposed in the Dabie Mountains due to intensive exhumation during the Late Jurassic, particularly after the Fenghuangtai depositional phase. Furthermore, it can be infered that the magmatic arc was initially present in both the Early Paleozoic and the Triassic, according to isotopic dating studies in previously published reports. δ13C–δ18O tracing between existing marbles of different strata in the Dabie block and marble gravels of the Fenghuangtai Formation in the Hefei Basin indicate that partial lithostratigraphic units for the Jurassic provenances have entirely disappeared from the Dabie block; therefore, it is impossible to reconstruct integral orogenic processes from studies on the remaining Dabie block alone. These findings, together with basin‐fill sequences, also suggest that the Hefei Basin was mainly subjected to compressive mechanical regimes rather than extensional regimes in the Jurassic, which resulted in reverse‐grading clastic depositional sequences, and is probably related to the northward intracontinental deep subduction of the Yangtze Plate. Regional exhumation properties and a tectonic model of the Late Mesozoic Dabie orogenesis are discussed in this paper.
If Your Mother Were an Animal, What Animal Would She Be? Creating Play‐Stories in Family Therapy: The Animal Attribution Story‐Telling Technique (AASTT)
Authors: Arad Diana
Published: April 2004

In this article, I describe a therapeutic story‐telling technique that requires family members to attribute an animal counterpart to each member of the family and then tell a short story—with a beginning, a middle, and an end—about the animal protagonists. The technique was applied in private practice to numerous families with a presenting problem of one or more children referred by the local school system labeled as suffering from conduct disorders and/or attention deficit hyperactivity disorder (ADHD).

This story‐telling technique offers a predictable structure to sessions, thus facilitating the engagement and participation of children of all ages in the therapeutic process. The animal name attribution to family members creates a fun, nonthreatening atmosphere that helps to promote the description of personality traits and interpersonal relationships through the various animal counterparts. The ensuing story allows each family member to describe situations, feelings, wishes, and more as belonging to the animals and not to themselves. This is an active process. It enables the expression of conflictual feelings, the clarification of erroneous beliefs about the self and others, and the externalization of wishes, fears, aggressive feelings, and fantasies within a safe context.

The combined use of animal selves and creative narrative takes into consideration children's developmental capabilities and utilizes their spontaneous pleasure in the world of make‐believe to minimize anxiety. In adults, this combination helps to overcome resistance and uncovers issues that are otherwise seldom verbalized. Further, play‐stories facilitate dialogue between family members and provide working metaphors that later become an integral part of the therapy sessions and of family lore.
RhoA-Derived Peptide Dimers Share Mechanistic Properties with Other Polyanionic Inhibitors of Respiratory Syncytial Virus (RSV), Including Disruption of Viral Attachment and Dependence on RSV G
Authors: Budge Philip J. , Li Yeqiang , Beeler Judy A. , Graham Barney S.
Published: April 2004

Large polyanionic molecules, such as sulfated polysaccharides (including soluble heparin and dextran sulfate), synthetic polyanionic polymers, and negatively charged proteins, have been shown to broadly inhibit several enveloped viruses. We recently reported the antiviral activity of a peptide derived from amino acids 77 to 95 of a potential binding partner of respiratory syncytial virus F protein (RSV F), the GTPase RhoA. A subsequent study with a truncated peptide (amino acids 80 to 94) revealed that optimal antiviral activity required dimerization via intermolecular disulfide bonds. We report here that the net negative charge of this peptide is also a determining factor for its antiviral activity and that it, like other polyanions, inhibits virus attachment. In a flow cytometry-based binding assay, peptide 80-94, heparin, and dextran sulfate inhibited the attachment of virus to cells at 4°C at the same effective concentrations at which they prevent viral infectivity. Interestingly, time-of-addition experiments revealed that peptide 80-94 and soluble heparin were also able to inhibit the infectivity of a virus that had been prebound to cells at 4°C, as had previously been shown for dextran sulfate, suggesting a potential role for postattachment effects of polyanions on RSV entry. Neutralization experiments with recombinant viruses showed that the antiviral activities of peptide 80-94 and dextran sulfate were diminished in the absence of the RSV attachment glycoprotein (G). Taken together, these data indicate that the antiviral activity of RhoA-derived peptides is functionally similar to that of other polyanions, is dependent on RSV G, and does not specifically relate to a protein-protein interaction between F and RhoA.
Conserved Cysteine-Rich Domain of Paramyxovirus Simian Virus 5 V Protein Plays an Important Role in Blocking Apoptosis
Authors: Sun Minghao , Rothermel Terri A. , Shuman Laurie , Aligo Jason A. , Xu Shibo , Lin Yuan , Lamb Robert A. , He Biao
Published: April 2004

The paramyxovirus family includes many well-known human and animal pathogens as well as emerging viruses such as Hendra virus and Nipah virus. The V protein of simian virus 5 (SV5), a prototype of the paramyxoviruses, contains a cysteine-rich C-terminal domain which is conserved among all paramyxovirus V proteins. The V protein can block both interferon (IFN) signaling by causing degradation of STAT1 and IFN production by blocking IRF-3 nuclear import. Previously, it was reported that recombinant SV5 lacking the C terminus of the V protein (rSV5VΔC) induces a severe cytopathic effect (CPE) in tissue culture whereas wild-type (wt) SV5 infection does not induce CPE. In this study, the nature of the CPE and the mechanism of the induction of CPE were investigated. Through the use of DNA fragmentation, terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling, and propidium iodide staining assays, it was shown that rSV5VΔC induced apoptosis. Expression of wt V protein prevented apoptosis induced by rSV5VΔC, suggesting that the V protein has an antiapoptotic function. Interestingly, rSV5VΔC induced apoptosis in U3A cells (a STAT1-deficient cell line) and in the presence of neutralizing antibody against IFN, suggesting that the induction of apoptosis by rSV5VΔC was independent of IFN and IFN-signaling pathways. Apoptosis induced by rSV5VΔC was blocked by a general caspase inhibitor, Z-VAD-FMK, but not by specific inhibitors against caspases 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 13, suggesting that rSV5VΔC-induced apoptosis can occur in a caspase 12-dependent manner. Endoplasmic reticulum stress can lead to activation of caspase 12; compared to the results seen with mock and wt SV5 infection, rSV5VΔC infection induced ER stress, as demonstrated by increased expression levels of known ER stress indicators GRP 78, GRP 94, and GADD153. These data suggest that rSV5VΔC can trigger cell death by inducing ER stress.
Unspliced Rous Sarcoma Virus Genomic RNAs Are Translated and Subjected to Nonsense-Mediated mRNA Decay before Packaging
Authors: LeBlanc Jason J. , Beemon Karen L.
Published: April 2004

Retroviruses package full-length, unspliced RNAs into progeny virions as dimerized RNA genomes. They also use unspliced RNAs as mRNAs to produce the
gag
and
pol
gene products. We asked whether a single Rous sarcoma virus (RSV) RNA can be translated and subsequently packaged or whether genomic packaging requires a nontranslated population of RNAs. We addressed this issue by utilizing the translation-dependent nonsense-mediated mRNA decay (NMD) pathway. NMD is the selective destruction of mRNAs bearing premature termination codons (PTCs). The pathway has been shown to be associated with splicing in higher eukaryotes. Here, we demonstrate that both translation and the cellular factor Upf1 are required for the decay of unspliced, PTC-bearing RSV RNA by the NMD pathway. To address the relationship between RNA translation and packaging, we examined virus produced in cells cotransfected with PTC-bearing retroviral clones and wild-type viral clones. We observed that PTC-bearing transcripts are packaged into viral particles at levels three- to fivefold less than those of control RNAs. Since PTC-mediated degradation requires translation, we conclude that RSV can package progeny virion particles using previously translated RNAs.
Acute Infection with Epstein-Barr Virus Targets and Overwhelms the Peripheral Memory B-Cell Compartment with Resting, Latently Infected Cells
Authors: Hochberg Donna , Souza Tatyana , Catalina Michelle , Sullivan John L. , Luzuriaga Katherine , Thorley-Lawson David A.
Published: April 2004

In this paper we demonstrate that during acute infection with Epstein-Barr virus (EBV), the peripheral blood fills up with latently infected, resting memory B cells to the point where up to 50% of all the memory cells may carry EBV. Despite this massive invasion of the memory compartment, the virus remains tightly restricted to memory cells, such that, in one donor, fewer than 1 in 10
4
infected cells were found in the naive compartment. We conclude that, even during acute infection, EBV persistence is tightly regulated. This result confirms the prediction that during the early phase of infection, before cellular immunity is effective, there is nothing to prevent amplification of the viral cycle of infection, differentiation, and reactivation, causing the peripheral memory compartment to fill up with latently infected cells. Subsequently, there is a rapid decline in infected cells for the first few weeks that approximates the decay in the cytotoxic-T-cell responses to viral replicative antigens. This phase is followed by a slower decline that, even by 1 year, had not reached a steady state. Therefore, EBV may approach but never reach a stable equilibrium.
Analysis of Host Range Phenotypes of Primate Hepadnaviruses by In Vitro Infections of Hepatitis D Virus Pseudotypes
Authors: Barrera Azeneth , Guerra Bernadette , Lee Helen , Lanford Robert E.
Published: April 2004

Hepatitis B virus (HBV) and woolly monkey hepatitis B virus (WMHBV) have natural host ranges that are limited to closely related species. The barrier for infection of primates seems to be at the adsorption and/or entry steps of the viral replication cycle, since a human hepatoma cell line is permissive for HBV and WMHBV replication following transfection of cloned DNA. We hypothesized that the HBV and WMHBV envelope proteins contain the principal viral determinants of host range. As previously shown by using the hepatitis D virus (HDV) system, recombinant HBV-HDV particles were infectious in chimpanzee as well as human hepatocytes. We extended the HDV system to include HDV particles pseudotyped with the WMHBV envelope. In agreement with the natural host ranges of HBV and WMHBV, in vitro infections demonstrated that HBV-HDV and WM-HDV particles preferentially infected human and spider monkey cells, respectively. Previous studies have implicated the pre-S1 region of the large (L) envelope protein in receptor binding and host range; therefore, recombinant HDV particles were pseudotyped with the hepadnaviral envelopes containing chimeric L proteins with the first 40 amino acids from the pre-S1 domain exchanged between HBV and WMHBV. Surprisingly, addition of the human amino terminus to the WMHBV L protein increased infectivity on spider monkey hepatocytes but did not increase infectivity for human hepatocytes. Based upon these data, we discuss the possibility that the L protein may be comprised of two domains that affect infectivity and that sequences downstream of residue 40 may influence host range and receptor binding or entry.
Cellular RNA Helicase p68 Relocalization and Interaction with the Hepatitis C Virus (HCV) NS5B Protein and the Potential Role of p68 in HCV RNA Replication
Authors: Goh Phuay-Yee , Tan Yee-Joo , Lim Siew Pheng , Tan Y. H. , Lim Seng Gee , Fuller-Pace Frances , Hong Wanjin
Published: April 2004

Chronic infection by hepatitis C virus (HCV) can lead to severe hepatitis and cirrhosis and is closely associated with hepatocellular carcinoma. The replication cycle of HCV is poorly understood but is likely to involve interaction with host factors. In this report, we show that NS5B, the HCV RNA-dependent RNA polymerase (RdRp), interacts with a human RNA helicase, p68. Transient expression of NS5B alone, as well as the stable expression of all the nonstructural proteins in a HCV replicon-bearing cell line (V. Lohmann, F. Korner, J.-O. Koch, U. Herian, L. Theilmann, and R. Bartenschlager, Science 285:110-113), causes the redistribution of endogenous p68 from the nucleus to the cytoplasm. Deletion of the C-terminal two-thirds of NS5B (NS5BΔC) dramatically reduces its coimmunoprecipitation (co-IP) with endogenous p68, while the deletion of the N-terminal region (NS5BΔN1 and NS5BΔN2) does not affect its interaction with p68. In consistency with the co-IP results, NS5BΔC does not cause the relocalization of p68 whereas NS5BΔN1 does. With a replicon cell line, we were not able to detect a change in positive- and negative-strand synthesis when p68 levels were reduced using small interfering RNA (siRNA). In cells transiently transfected with a full-length HCV construct, however, the depletion (using specific p68 siRNA) of endogenous p68 correlated with a reduction in the transcription of negative-strand from positive-strand HCV RNA. Overexpression of NS5B and NS5BΔN1, but not that of NS5BΔC, causes a reduction in the negative-strand synthesis, indicating that overexpressed NS5B and NS5BΔN1 sequesters p68 from the replication complexes (thus reducing their replication activity levels). Identification of p68 as a cellular factor involved in HCV replication, at least for cells transiently transfected with a HCV expression construct, is a step towards understanding HCV replication.
Frequent Dual Initiation in Human Immunodeficiency Virus-Based Vectors Containing Two Primer-Binding Sites: a Quantitative In Vivo Assay for Function of Initiation Complexes
Authors: Voronin Yegor A. , Pathak Vinay K.
Published: April 2004

We previously demonstrated that murine leukemia virus (MLV)-based vectors containing two primer-binding sites (PBSs) have the capacity to initiate reverse transcription more than once (Y. A. Voronin and V. K. Pathak, Virology
312:
281-294, 2003). To determine whether human immunodeficiency virus (HIV)-based vectors also have the capacity to initiate reverse transcription twice, we constructed an HIV type 1 (HIV-1)-based vector containing the HIV-1 PBS, a green fluorescent protein reporter gene (
GFP
), and a second PBS derived from HIV-2 3′ of
GFP
. Simultaneous initiation of reverse transcription at both the 5′ HIV-1 PBS and 3′ HIV-2 PBS was predicted to result in deletion of
GFP
. As in the MLV-based vectors,
GFP
was deleted in approximately 25% of all proviruses, indicating frequent dual initiation in HIV-based vectors containing two PBSs. Quantitative real-time PCR analysis of early reverse transcription products indicated that HIV-1 reverse transcriptase efficiently used the HIV-2 PBS. To investigate tRNA primer-RNA template interactions in vivo, we introduced several mutations in the HIV-2 U5 region. The effects of these mutations on the efficiency of reverse transcription initiation were measured by quantitative real-time PCR analysis of early reverse transcription products, with initiation at the HIV-1 PBS used as an internal control. Disruption of the lower and upper parts of the U5-inverted repeat stem reduced the efficiency of initiation 20- and 6-fold, respectively. In addition, disruption of the proposed interactions between viral RNA and tRNA
Lys3
thymidine-pseudouridine-cytidine and anticodon loops decreased the efficiency of initiation seven- and sixfold, respectively. These results demonstrate the relative influence of various RNA-RNA interactions on the efficiency of initiation in vivo. Furthermore, the two-PBS vector system provides a sensitive and quantitative in vivo assay for analysis of RNA-RNA and protein-RNA interactions that can influence the efficiency of reverse transcription initiation.
Induction of Disease by a Molecularly Cloned Highly Pathogenic Simian Immunodeficiency Virus/Human Immunodeficiency Virus Chimera Is Multigenic
Authors: Sadjadpour Reza , Theodore Theodore S. , Igarashi Tatsuhiko , Donau Olivia K. , Plishka Ronald J. , Buckler-White Alicia , Martin Malcolm A.
Published: April 2004

One of three full-length infectious molecular clones of SHIVDH12R, designated SHIVDH12R-CL-7and obtained from productively infected rhesus monkey peripheral blood mononuclear cells, directed rapid and irreversible loss of CD4+T cells within 3 weeks of its inoculation into Indian rhesus monkeys. Induction of complete CD4+T-cell depletion by SHIVDH12R-CL-7was found to be dependent on inoculum size. The acquisition of this pathogenic phenotype was accompanied by the introduction of 42 amino acid substitutions into multiple genes of parental nonpathogenic SHIVDH12. Transfer of the entire SHIVDH12R-CL-7envgene into the genetic background of nonpathogenic SHIVDH12failed to confer the rapid CD4+T-lymphocyte-depleting syndrome; similarly, the substitution ofgagpluspolsequences from SIVsmE543for analogous SIVmac239genes in SHIVDH12R-CL-7attenuated the pathogenic phenotype. Amino acid changes affecting multiple viral genes are necessary, but insufficient by themselves, to confer the prototypically rapid and irreversible CD4+T-cell-depleting phenotype exhibited by molecularly cloned SHIVDH12R-CL-7.
Effects of Antibody on Viral Kinetics in Simian/Human Immunodeficiency Virus Infection: Implications for Vaccination
Authors: Zhang Lei , Ribeiro Ruy M. , Mascola John R. , Lewis Mark G. , Stiegler Gabriela , Katinger Hermann , Perelson Alan S. , Davenport Miles P.
Published: April 2004

Passive antibody treatment of macaques prior to simian/human immunodeficiency virus infection produces “sterilizing immunity” in some animals and long-term reductions in viral loads in others. Analysis of viral kinetics suggests that antibody mediates sterilizing immunity by its effects on the initial viral inoculum. By contrast, reduction in peak viral load later in infection prevents CD4 depletion and contributes to long-term viral control.
Lessons Learned from Political Violence and Genocide in Teaching a Psychology of Peace: An Interview with Linda Woolf
Authors: Howe Tasha R.
Published: April 2004

Tasha R. Howe got her BA in psychology from the University of California at Santa Barbara. She received her MA and PhD in developmental psychology from the University of California, Riverside. After doing an NIMH-sponsored postdoctoral fellowship in developmental psychopathology at Vanderbilt University, she served as assistant professor of psychology at Transylvania University in Lexington, Kentucky. Currently as assistant professor of psychology at Humboldt State University in California, Dr. Howe specializes in child abuse, family violence, developmental psychopathology, community violence, and ecological factors affecting normal and atypical child development. She teaches a wide variety of courses, including human development, the history of psychology, family violence, assessment and treatment of child abuse and neglect, children's cognitive development, and developmental psychopathology. She is married and has two sons, ages 6 and 1.

Linda M. Woolf is the Coordinator of Holocaust and Genocide Studies and Professor of Psychology at Webster University in St. Louis, Missouri. She received her MS and PhD in applied-experimental psychology from Saint Louis University. She currently serves as Review Editor for the e-journal H-Genocide, secretary for the Society for the Teaching of Psychology (Division 2, APA), and an executive committee member for the Society for the Study of Peace, Conflict, and Violence (Division 48, APA). In addition to her courses on the Holocaust, genocide, peace and conflict, and women and global human rights, Dr. Woolf also teaches a wide variety of courses such as women's intellectual contributions to the study of mind and society, the history and systems of psychology, social psychology, adult development and aging, and introductory psychology. She loves baseball, Star Trek, and her dogs and cats!
Why are Some Undergraduates More (and others Less) Interested in Psychological Research?
Authors: Vittengl Jeffrey R. , Bosley Cheylynne Y. , Brescia Sierra A. , Eckardt Elizabeth A. , Neidig Jennifer M. , Shelver Kristen S. , Sapenoff Laura A.
Published: April 2004

Theorists consider student interest central to effective education, but undergraduates have varying interest in psychological research. We developed a measure of interest in psychological research and tested person-level predictors of interest in a sample of undergraduate psychology students (N = 139). Interest in psychological research was low to moderate, on average, with greater interest in relatively passive and low-commitment research activities. Predictors of greater interest in psychological research included personality (openness to experience), academic aptitude (higher ACT scores), perceived relevance of research to post- undergraduate activities, and plans to enter a PhD program. We discuss these results in the context of teaching strategies intended to improve psychological research education.
Use of Terrestrial Hermit Crabs in the Study of Habituation
Authors: Nolan Laurence J.
Published: April 2004

For small colleges, the use of invertebrates in undergraduate learning laboratory experiments may be a valuable alternative to the use of vertebrate species. This article describes a habituation experiment using terrestrial hermit crabs. All of the materials required are inexpensive and readily available. What makes this experiment unique is that although the instructor sets basic parameters, students have a crucial role in the experiment's design and the analysis of collected data. Assessment of learning outcomes and student evaluations indicate that conducting this experiment aided in students' learning of behavioral techniques, habituation phenomena and theory, and the role of habituation in the lives of organisms.
Ceramics in Nanotech Revolution
Authors: Arora A.
Published: April 2004

‘Nanotechnology’, called the materials technology of 21st century has also entered the field of ceramics. Nanoceramic systems, their synthesis, characterization and the changed properties in view of chemistry of nanoparticles are discussed along with the applications of nanoceramics. In the end the major challenges being encountered like scaling‐up the synthesis of nanoceramics for development of industrial scale methods are discussed
A Novel Pulse‐Current‐Assisted Sintering Method for Fabrication of Metallic Cellular Structures
Authors: Song Z. , Kishimoto S. , Shinya N.
Published: April 2004

A novel isostatic pressing method by spark plasma sintering system is presented for the fabrication of cellular metals. It is a faster and more flexible sintering method compared with traditional hot pressing. The authors show that cellular metal with fine and controllable structure can be fabricated by this method.
Nanolithographie und Nanochemie: Sondentechniken zur Strukturierung und chemischen Modifizierung von Nanobauelementen
Authors: Wouters Daan , Schubert Ulrich S.
Published: April 2004

Da photolithographisch nicht beliebig kleine Bauelemente hergestellt werden können, werden andere Strukturierungstechniken intensiv untersucht. Insbesondere Rastersondenlithographie‐Techniken gelten als vielversprechend für die Erzeugung solcher Strukturen, und da ihre Anwendung relativ einfach ist, sind diese Methoden inzwischen weit verbreitet. Beispiele sind die Dip‐Pen‐Lithographie und die kraftinduzierte lokale Strukturierung ebenso wie die lokale Oxidation mit Sonden. Diese Techniken sind besonders interessant, da so Nanostrukturen erhalten werden, die chemisch und physikalisch modifiziert und funktionalisiert werden können. Somit ist nicht nur die Produktion von elektronischen Bauelementen möglich, sondern auch die Erzeugung von Strukturen für die molekulare Erkennung oder die Sensorik. Wir zeigen hier die Fortschritte bei der Entwicklung von automatisierten Multispitzen‐Rastersondensystemen und ihre Anwendung bei der lokalen Oxidation. Außerdem erläutern wir den Stand der Technik und die Perspektiven von Nanobauelementen.
Electrochemistry/Mass Spectrometry (EC/MS)—A New Tool To Study Drug Metabolism and Reaction Mechanisms
Authors: Karst Uwe
Published: April 2004

A great combination: The coupling of electrochemistry and mass spectrometry (EC/MS) opens up new possibilities in analytics—not only in biochemistry for the investigation of natural products and metabolites, but also in the screening of combinatorial libraries and the characterization of transition‐metal complexes. The mode of operation, range of application, and perspectives of the current EC/MS methods are the themes of this Highlight.
Development of calibration models for estimation of monomer concentration by Raman spectroscopy during emulsion polymerization: Facing the medium heterogeneity
Authors: Reis Marlon M. , Araújo Pedro H. H. , Sayer Claudia , Giudici Reinaldo
Published: April 2004

This work compares different calibration models for the estimation of monomer concentrations by Raman spectroscopy during semicontinuous emulsion copolymerization reactions. The limitations of these models are discussed in terms of a complex reaction, namely the copolymerization of vinyl acetate and butyl acrylate, whose monomers present overlapping Raman spectra, especially the C=C stretching band. Additionally, the copolymerization was monitored in a spectroscopic setup arranged for fast spectral acquisition, which resulted in a low signal‐to‐noise ratio. These realistic conditions for in‐line monitoring of emulsion copolymerization, i.e., considerable noise level in the spectra and medium heterogeneity, are discussed in the context of different approaches for adjusting the calibration model and the ensuing model limitations. It was verified that combining data obtained during reactions with synthetic samples is interesting from the statistical point of view, since in this way it is possible to produce data sets with a wide range of variation, allowing the accurate estimation of statistical parameters. These parameters are of major importance for process variables and product property estimations, especially if they are to be used for process control and decision making purposes. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1136–1150, 2004
A study on the biodegradability of polyethylene terephthalate fiber and diethylene glycol terephthalate
Authors: Zhang Jianfei , Wang Xiaochun , Gong Jixian , Gu Zhenya
Published: April 2004

The degradation of diethylene glycol terephthalate (DTP) and polyethylene terephthalate fiber (PET fiber) by microbes and lipase was studied. The HPLC method was used to determine the degradation ratio and degradation rule of DTP. Greater than 90% DTP was degraded by microbes in 24 days and 40% by lipase in 24 h. The degradation of DTP can be described by the first‐order reaction model. Although the biodegradation ratio of PET fiber was still weak, we demonstrated with SEM micrographs and HPLC analysis that microbes and lipase could act on the PET fiber and there were some cracks on the surface of the fiber. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1089–1096, 2004