bluuebunny/crossref_metadata_2025 huggingface dataset:
Complete Genome Sequence and In Planta Subcellular Localization of Maize Fine Streak Virus Proteins
Authors: Tsai Chi-Wei , Redinbaugh Margaret G. , Willie Kristen J. , Reed Sharon , Goodin Michael , Hogenhout Saskia A.
Published: April 2005

The genome of the nucleorhabdovirus maize fine streak virus (MFSV) consists of 13,782 nucleotides of nonsegmented, negative-sense, single-stranded RNA. The antigenomic strand consisted of seven open reading frames (ORFs), and transcripts of all ORFs were detected in infected plants. ORF1, ORF6, and ORF7 had significant similarities to the nucleocapsid protein (N), glycoprotein (G), and polymerase (L) genes of other rhabdoviruses, respectively, whereas the ORF2, ORF3, ORF4, and ORF5 proteins had no significant similarities. The N (ORF1), ORF4, and ORF5 proteins localized to nuclei, consistent with the presence of nuclear localization signals (NLSs) in these proteins. ORF5 likely encodes the matrix protein (M), based on its size, the position of its NLS, and the localization of fluorescent protein fusions to the nucleus. ORF2 probably encodes the phosphoprotein (P) because, like the P protein of
Sonchus yellow net virus
(SYNV), it was spread throughout the cell when expressed alone but was relocalized to a subnuclear locus when coexpressed with the MFSV N protein. Unexpectedly, coexpression of the MFSV N and P proteins, but not the orthologous proteins of SYNV, resulted in accumulations of both proteins in the nucleolus. The N and P protein relocalization was specific to cognate proteins of each virus. The subcellular localizations of the MFSV ORF3 and ORF4 proteins were distinct from that of the SYNV sc4 protein, suggesting different functions. To our knowledge, this is the first comparative study of the cellular localizations of plant rhabdoviral proteins. This study indicated that plant rhabdoviruses are diverse in genome sequence and viral protein interactions.
ATPγS Disrupts Human Immunodeficiency Virus Type 1 Virion Core Integrity
Authors: Gurer Cagan , Höglund Anders , Höglund Stefan , Luban Jeremy
Published: April 2005

Heat shock protein 70 (Hsp70) is incorporated within the membrane of primate lentiviral virions. Here we demonstrate that Hsp70 is also incorporated into oncoretroviral virions and that it remains associated with membrane-stripped human immunodeficiency virus type 1 (HIV-1) virion cores. To determine if Hsp70 promotes virion infectivity, we attempted to generate Hsp70-deficient virions withgagdeletion mutations, Hsp70 transdominant mutants, or RNA interference, but these efforts were confounded, largely because they disrupt virion assembly. Given that polypeptide substrates are bound and released by Hsp70 in an ATP-hydrolytic reaction cycle, we supposed that incubation of HIV-1 virions with ATP would perturb Hsp70 interaction with substrates in the virion and thereby decrease infectivity. Treatment with ATP or ADP had no observable effect, but ATPγS and GTPγS, nucleotide triphosphate analogues resistant to Hsp70 hydrolysis, dramatically reduced the infectivity of HIV-1 and murine leukemia virus virions. ATPγS-treated virions were competent for fusion with susceptible target cells, but viral cDNA synthesis was inhibited to an extent that correlated with the magnitude of decrease in infectivity. Intravirion reverse transcription by HIV-1, simian immunodeficiency virus, or murine leukemia virus was also inhibited by ATPγS. The effects of ATPγS on HIV-1 reverse transcription appeared to be indirect, resulting from disruption of virion core morphology that was evident by transmission electron microscopy. Consistent with effects on capsid conformation, ATPγS-treated viruslike particles failed to saturate host antiviral restriction activity. Our observations support a model in which the catalytic activity of virion-associated Hsp70 is required to maintain structural integrity of the virion core.
Recruitment of CBP/p300, TATA-Binding Protein, and S8 to Distinct Regions at the N Terminus of Adenovirus E1A
Authors: Rasti Mozhgan , Grand Roger J. A. , Mymryk Joe S. , Gallimore Phillip H. , Turnell Andrew S.
Published: April 2005

The N-terminal region of the adenovirus (Ad) 12S E1A gene product targets several cellular proteins that are essential for the induction of S phase, cellular immortalization, cellular transformation, transcriptional repression, and transcriptional activation. The precise binding sites for these proteins, however, remain to be resolved. We therefore undertook an extensive site-directed mutagenesis approach to generate specific point mutants and to precisely map the binding sites for CBP, p300, TATA-binding protein (TBP), S4, S8, hGcn5, P/CAF, and Ran within the first 30 amino acids of the Ad5 12S E1A protein. We determined that although common residues within the N-terminal region can form partial binding sites for these proteins, point mutants were also generated that could discriminate between binding sites. These data indicate that AdE1A can target each of these proteins individually through distinct binding sites. It was evident, however, that the mutation of specific hydrophobic residues typically had the greatest effect upon AdE1A's ability to bind individual partners. Indeed, the mutation of L at positions 19 and 20 eliminated the ability of AdE1A to interact with any of the N-terminal binding proteins studied here. Interestingly, although TBP and S8 or CBP/p300 can exist as functional complexes, RNA interference revealed that the recruitment of either TBP, S8, or CBP/p300 to AdE1A was not dependent upon the expression of the other proteins. These data further indicate that AdE1A can target individual partner proteins in vivo and that it does not necessarily recruit these proteins indirectly as components of larger macromolecular complexes. Finally, we took advantage of the fine-mapping data to ascertain which proteins were targeted during the transformation process. Consistent with previous studies, CBP/p300 was found to be targeted by AdE1A during this process, although our data suggest that binding to other N-terminal proteins is also important for transformation.
Early T-Cell Responses to Dengue Virus Epitopes in Vietnamese Adults with Secondary Dengue Virus Infections
Authors: Simmons Cameron P. , Dong Tao , Chau Nguyen Vinh , Dung Nguyen Thi Phuong , Chau Tran Nguyen Bich , Thao Le Thi Thu , Dung Nguyen Thi , Hien Tran Tinh , Rowland-Jones Sarah , Farrar Jeremy
Published: April 2005

T-cell responses to dengue viruses may be important in both protective immunity and pathogenesis. This study of 48 Vietnamese adults with secondary dengue virus infections defined the breadth and magnitude of peripheral T-cell responses to 260 overlapping peptide antigens derived from a dengue virus serotype 2 (DV2) isolate. Forty-seven different peptides evoked significant gamma interferon enzyme-linked immunospot (ELISPOT) assay responses in 39 patients; of these, 34 peptides contained potentially novel T-cell epitopes. NS3 and particularly NS3200-324were important T-cell targets. The breadth and magnitude of ELISPOT responses to DV2 peptides were independent of the infecting dengue virus serotype, suggesting that cross-reactive T cells dominate the acute response during secondary infection. Acute ELISPOT responses were weakly correlated with the extent of hemoconcentration in individual patients but not with the nadir of thrombocytopenia or overall clinical disease grade. NS3556-564and Env414-422were identified as novel HLA-A*24 and B*07-restricted CD8+T-cell epitopes, respectively. Acute T-cell responses to natural variants of Env414-422and NS3556-564were largely cross-reactive and peaked during disease convalescence. The results highlight the importance of NS3 and cross-reactive T cells during acute secondary infection but suggest that the overall breadth and magnitude of the T-cell response is not significantly related to clinical disease grade.
Inhibition of Lysosome and Proteasome Function Enhances Human Immunodeficiency Virus Type 1 Infection
Authors: Wei Bangdong L. , Denton Paul W. , O'Neill Eduardo , Luo Tianci , Foster John L. , Garcia J. Victor
Published: April 2005

We previously reported that inhibition of endosomal/lysosomal function can dramatically enhance human immunodeficiency virus type 1 (HIV-1) infectivity, suggesting that under these conditions productive HIV-1 infection can occur via the endocytic pathway. Here we further examined this effect with bafilomycin A1 (BFLA-1) and show that this enhancement of infectivity extends to all HIV-1 isolates tested regardless of coreceptor usage. However, isolate-specific differences were observed in the magnitude of the effect. This was particularly evident in the case of the weakly infectious HIV-1SF2, for which we observed the greatest enhancement. Using reciprocal chimeric viruses, we were able to determine that both the disproportionate increase in the infectivity of HIV-1SF2in response to BFLA-1 and its weak infectivity in the absence of BFLA-1 mapped to its envelope gene. Further, we found HIV-1SF2to have lower fusion activity and to be 12-fold more sensitive to the fusion inhibitor T-20 than HIV-1NL4-3. Proteasomal inhibitors also enhance HIV-1 infectivity, and we report that the combination of a lysosomal and a proteasomal inhibitor greatly enhanced infectivity of all isolates tested. Again, HIV-1SF2was unique in exhibiting a synergistic 400-fold increase in infectivity. We also determined that inhibition of proteasomal function increased the infectivity of HIV-1 pseudotyped with vesicular stomatitis virus G protein. The evidence presented here highlights the important role of the lysosomes/proteasomes in the destruction of infectious HIV-1SF2and could have implications for the development of novel antiviral agents that might take advantage of these innate defenses.
Homologous Crossovers among Molecules of Brome Mosaic Bromovirus RNA1 or RNA2 Segments In Vivo
Authors: Urbanowicz Anna , Alejska Magdalena , Formanowicz Piotr , Błażewicz Jacek , Figlerowicz Marek , Bujarski Jozef J.
Published: April 2005

Previously we demonstrated frequent homologous crossovers among molecules of the RNA3 segment in the tripartite brome mosaic bromovirus (BMV) RNA genome (A. Bruyere, M. Wantroba, S. Flasinski, A. Dzianott, and J. J. Bujarski, J. Virol.
74:
4214-4219, 2000). To further our knowledge about mechanisms of viral RNA genome variability, in this paper we have studied homologous recombination in BMV RNA1 and RNA2 components during infection. We have found that basal RNA-RNA crossovers could occur within coding regions of both RNAs, although recombination frequencies slightly varied at different RNA sections. In all cases, the frequencies were much lower than the rate observed for the intercistronic recombination hot spot in BMV RNA3. Probability calculations accounted for at least one homologous crossover per RNA molecule per replication cycle. In addition, we have demonstrated an efficient repair of mutations within the conserved 3′ and 5′ noncoding regions, most likely due to error-prone BMV RNA replication. Overall, our data verify that homologous crossovers are common events a during virus life cycle, and we discuss their importance for viral RNA genetics.
Coat Protein Activation of Alfalfa Mosaic Virus Replication Is Concentration Dependent
Authors: Guogas Laura M. , Laforest Siana M. , Gehrke Lee
Published: April 2005

Alfalfa mosaic virus (AMV) and ilarvirus RNAs are infectious only in the presence of the viral coat protein; therefore, an understanding of coat protein's function is important for defining viral replication mechanisms. Based on in vitro replication experiments, the conformational switch model states that AMV coat protein blocks minus-strand RNA synthesis (R. C. Olsthoorn, S. Mertens, F. T. Brederode, and J. F. Bol, EMBO J. 18:4856-4864, 1999), while another report states that coat protein present in an inoculum is required to permit minus-strand synthesis (L. Neeleman and J. F. Bol, Virology 254:324-333, 1999). Here, we report on experiments that address these contrasting results with a goal of defining coat protein′s function in the earliest stages of AMV replication. To detect coat-protein-activated AMV RNA replication, we designed and characterized a subgenomic luciferase reporter construct. We demonstrate that activation of viral RNA replication by coat protein is concentration dependent; that is, replication was strongly stimulated at low coat protein concentrations but decreased progressively at higher concentrations. Genomic RNA3 mutations preventing coat protein mRNA translation or disrupting coat protein's RNA binding domain diminished replication. The data indicate that RNA binding and an ongoing supply of coat protein are required to initiate replication on progeny genomic RNA transcripts. The data do not support the conformational switch model's claim that coat protein inhibits the initial stages of viral RNA replication. Replication activation may correlate with low local coat protein concentrations and low coat protein occupancy on the multiple binding sites present in the 3′ untranslated regions of the viral RNAs.
Scavenger Receptor Class B Type I and Hepatitis C Virus Infection of PrimaryTupaiaHepatocytes
Authors: Barth Heidi , Cerino Raffaele , Arcuri Mirko , Hoffmann Marco , Schürmann Peter , Adah Mohammed I. , Gissler Bettina , Zhao Xiping , Ghisetti Valeria , Lavezzo Bruna , Blum Hubert E. , von Weizsäcker Fritz , Vitelli Alessandra , Scarselli Elisa , Baumert Thomas F.
Published: April 2005

Hepatitis C virus (HCV) is a major cause of chronic hepatitis worldwide. The study of early steps during HCV infection has been hampered by the lack of suitable in vitro or in vivo models. PrimaryTupaiahepatocytes (PTH) have been shown to be susceptible to HCV infection in vitro and in vivo. Human scavenger receptor class B type I (SR-BI) represents an HCV receptor candidate mediating the cellular binding of E2 glycoprotein to HepG2 hepatoma cells. However, the function of SR-BI for viral infection of hepatocytes is unknown. In this study, we used PTH to assess the functional role of SR-BI as a putative HCV receptor. Sequence analysis of cloned tupaia SR-BI revealed a high homology between tupaia and human SR-BI. Transfection of CHO cells with human or tupaia SR-BI but not mouse SR-BI cDNA resulted in cellular E2 binding, suggesting that E2-binding domains between human and tupaia SR-BI are highly conserved. Preincubation of PTH with anti-SR-BI antibodies resulted in marked inhibition of E2 or HCV-like particle binding. However, anti-SR-BI antibodies were not able to block HCV infection of PTH. In conclusion, our results demonstrate that SR-BI represents an important cell surface molecule for the binding of the HCV envelope to hepatocytes and suggest that other or additional cell surface molecules are required for the initiation of HCV infection. Furthermore, the structural and functional similarities between human and tupaia SR-BI indicate that PTH represent a useful model system to characterize the molecular interaction of the HCV envelope and SR-BI on primary hepatocytes.
Effect of Antiviral Treatment with Entecavir on Age- and Dose-Related Outcomes of Duck Hepatitis B Virus Infection
Authors: Foster Wendy K. , Miller Darren S. , Scougall Catherine A. , Kotlarski Ieva , Colonno Richard J. , Jilbert Allison R.
Published: April 2005

Entecavir (ETV), a potent inhibitor of the hepadnaviral polymerases, prevented the development of persistent infection when administered in the early stages of duck hepatitis B virus (DHBV) infection. In a preliminary experiment, ETV treatment commenced 24 h before infection showed no significant advantage over simultaneous ETV treatment and infection. In two further experiments 14-day-old ducks were inoculated with DHBV-positive serum containing 10
4
, 10
6
, 10
8
, or 5 × 10
8
viral genomes (vge) and were treated orally with 1.0 mg/kg of body weight/day of ETV for 14 or 49 days. A relationship between virus dose and infection outcome was seen: non-ETV-treated ducks inoculated with 10
4
vge had transient infection, while ducks inoculated with higher doses developed persistent infection. ETV treatment for 49 days did not prevent initial infection of the liver but restricted the spread of infection more than ∼1,000-fold, a difference which persisted throughout treatment and for up to 49 days after withdrawal. Ultimately, three of seven ETV-treated ducks resolved their DHBV infection, while the remaining ducks developed viremia and persistent infection after a lag period of at least 63 days. ETV treatment for 14 days also restricted the spread of infection, leading to marked and sustained reductions in the number of DHBV-positive hepatocytes in 7 out of 10 ducks. In conclusion, short-term suppression with ETV provides opportunity for the immune response to successfully control DHBV infection. Since DHBV infection of ducks provides a good model system for HBV infection in humans, it seems likely that ETV may be useful in postexposure therapy for HBV infection aimed at preventing the development of persistent infection.
Aged BALB/c Mice as a Model for Increased Severity of Severe Acute Respiratory Syndrome in Elderly Humans
Authors: Roberts Anjeanette , Paddock Christopher , Vogel Leatrice , Butler Emily , Zaki Sherif , Subbarao Kanta
Published: April 2005

Advanced age has repeatedly been identified as an independent correlate of adverse outcome and a predictor of mortality in cases of severe acute respiratory syndrome (SARS). SARS-associated mortality may exceed 50% for persons aged 60 years or older. Heightened susceptibility of the elderly to severe SARS and the ability of SARS coronavirus to replicate in mice led us to examine whether aged mice might be susceptible to disease. We report here that viral replication in aged mice was associated with clinical illness and pneumonia, demonstrating an age-related susceptibility to SARS disease in animals that parallels the human experience.
Endoplasmic Reticulum-Localized Human Papillomavirus Type 16 E5 Protein Alters Endosomal pH but Not
trans
-Golgi pH
Authors: Disbrow Gary L. , Hanover John A. , Schlegel Richard
Published: April 2005

The human papillomavirus type 16 (HPV-16) E5 protein is a small, hydrophobic polypeptide that is expressed in virus-infected keratinocytes and alters receptor signaling pathways, apoptotic responses, and endosomal pH. Despite its ability to inhibit endosomal acidification, the HPV-16 E5 protein is found predominantly in the endoplasmic reticulum (ER), suggesting that its effect may be indirect and perhaps global. To determine whether E5 alters the pHs of additional intracellular compartments, we transduced human keratinocytes with a codon-optimized E5 vector and then quantified endosomal and
trans
-Golgi pHs using sensitive, compartment-specific, ratiometric pHluorin constructs. E5 protein increased endosomal pH from 5.9 to 6.9 but did not affect the normal
trans
-Golgi pH of 6.3. Confirming the lack of alteration in
trans
-Golgi pH, we observed no alterations in the acidification-dependent processing of the proH3 protein. C-terminal deletions of E5, which retained normal expression and localization in the ER, were defective for endosomal alkalization. Thus, E5 does not uniformly alkalinize intracellular compartments, and its C-terminal 10 amino acids appear to mediate interactions with critical ER targets that modulate proton pump function and/or localization.
Pathological Prion Protein in the Tongues of Sheep Infected with Naturally Occurring Scrapie
Authors: Casalone Cristina , Corona Cristiano , Crescio Maria Ines , Martucci Francesca , Mazza Maria , Ru Giuseppe , Bozzetta Elena , Acutis Pier Luigi , Caramelli Maria
Published: April 2005

Tongue involvement by prion spreading was shown to be a common outcome after oral or intracranial experimental challenge with scrapie and transmissible mink encephalopathy sources in rodent models. It is also known that bovine spongiform encephalopathy, which is pathogenic for humans, is experimentally transmissible to sheep and can lead to a disease indistinguishable from scrapie. A recent European Food Safety Authority opinion recommended research into PrP
sc
accumulation in the tongues of ruminants. We report on the detection of PrP
sc
in the tongues of seven scrapie-infected sheep by immunohistochemistry and Western blotting.
Nearby Clusters of Hemagglutinin Residues Sustain SLAM-Dependent Canine Distemper Virus Entry in Peripheral Blood Mononuclear Cells
Authors: von Messling Veronika , Oezguen Numan , Zheng Qi , Vongpunsawad Sompong , Braun Werner , Cattaneo Roberto
Published: April 2005

Signaling lymphocytic activation molecule (SLAM, CD150) is the universal morbillivirus receptor. Based on the identification of measles virus (MV) hemagglutinin (H) amino acids supporting human SLAM-dependent cell entry, we mutated canine distemper virus (CDV) H and identified residues necessary for efficient canine SLAM-dependent membrane fusion. These residues are located in two nearby clusters in a new CDV H structural model. To completely abolish SLAM-dependent fusion, combinations of mutations were necessary. We rescued a SLAM-blind recombinant CDV with six mutations that did not infect ferret peripheral blood mononuclear cells while retaining full infectivity in epithelial cells.
Viral RNA Is Required for the Association of APOBEC3G with Human Immunodeficiency Virus Type 1 Nucleoprotein Complexes
Authors: Khan Mohammad A. , Kao Sandra , Miyagi Eri , Takeuchi Hiroaki , Goila-Gaur Ritu , Opi Sandrine , Gipson Clay L. , Parslow Tristram G. , Ly Hinh , Strebel Klaus
Published: April 2005

APOBEC3G (APO3G) is a host cytidine deaminase that is incorporated into human immunodeficiency virus type 1 (HIV-1) particles. We report here that viral RNA promotes stable association of APO3G with HIV-1 nucleoprotein complexes (NPC). A target sequence located within the 5′-untranslated region of the HIV-1 RNA was identified to be necessary and sufficient for efficient APO3G packaging. Fine mapping revealed a sequence normally involved in viral genomic RNA dimerization and Gag binding to be important for APO3G packaging and association with viral NPC. Our data suggest that packaging of APO3G into HIV-1 NPC is enhanced by viral RNA.
Induction of Lytic Epstein-Barr Virus (EBV) Infection by Synergistic Action of Rituximab and Dexamethasone Renders EBV-Positive Lymphoma Cells More Susceptible to Ganciclovir Cytotoxicity In Vitro and In Vivo
Authors: Daibata Masanori , Bandobashi Kentaro , Kuroda Masayuki , Imai Shosuke , Miyoshi Isao , Taguchi Hirokuni
Published: April 2005

The purposeful induction of the lytic form of Epstein-Barr virus (EBV) infection combined with ganciclovir (GCV) treatment has been advocated as a novel strategy for EBV-positive B-cell lymphoma. We demonstrated that rituximab had a synergistic effect with dexamethasone on induction of the lytic EBV infection in CD20-positive lymphoma cells. Addition of GCV to the dexamethasone/rituximab-treated cells was more effective than dexamethasone/rituximab alone in killing EBV-positive lymphoma cells in vitro and in lymphoma-bearing nude mice but not in EBV-negative cells. These data suggest that induction of the lytic EBV infection with dexamethasone/rituximab in combination with GCV could be a potential virally targeted therapy for EBV-associated B-cell lymphoma.
Hyperphosphorylation of EBNA2 by Epstein-Barr Virus Protein Kinase Suppresses Transactivation of the LMP1 Promoter
Authors: Yue Wei , Gershburg Edward , Pagano Joseph S.
Published: April 2005

The Epstein-Barr virus (EBV) BGLF4 gene encodes a serine/threonine protein kinase (PK) that is expressed in the cytolytic cycle. EBV nuclear antigen 2 (EBNA2) is a key latency gene essential for immortalization of B lymphocytes and transactivation of viral and cellular promoters. Here we report that EBV PK phosphorylates EBNA2 at Ser-243 and that these two proteins physically associate. PK suppresses EBNA2's ability to transactivate the LMP1 promoter, and Ser-243 of EBNA2 is involved in this suppression. Moreover, EBNA2 is hyperphosphorylated during EBV reactivation in latently infected B cells, which is associated with decreased LMP1 protein levels. This is the first report about the effect of EBV PK on the function of one of its target proteins and regulation of EBNA2 phosphorylation during the EBV lytic cycle.
ABSORPTION AND REFLECTION EXPERIMENTS ON HIGH-MOBILITY 2DEGs IN THE REGIME OF MICROWAVE-INDUCED RESISTANCE OSCILLATIONS
Authors: STUDENIKIN S. A. , POTEMSKI M. , SACHRAJDA A. S. , HILKE M. , PFEIFFER L. N. , WEST K. W.
Published: April 2005

We have performed microwave absorption and near-field reflection experiments on a high mobility GaAs / AlGaAs heterostructure for the same conditions for which Microwave-Induced Resistance Oscillations (MIROs) are observed. It is shown that the electrodynamic aspect of the problem is important in these experiments. In the absorption experiments a broad CR line was observed due to a large reflection from the highly conductive electron gas. There were no additional features observed related to absorption at harmonics of the cyclotron resonance.

In near-field reflection experiments a very different oscillation pattern was revealed when compared to MIROs. The oscillation pattern observed in the reflection experiments is probably due to plasma effects occurring in a finite-size sample. The whole microscopic picture of MIROs is more complicated than simply a resonant absorption at harmonics of the cyclotron resonance. Nevertheless, the experimental observations are in good agreement with the model by Durst et al. involving the photo-assisted scattering in the presence of a crossed magnetic field and dc bias. The observed damping factor of MIROs may be attributed to a change in the electron mobility as a function of temperature.

MIROs may be considered as a light-induced drift effect, a broad class of phenomena associated with a light-induced asymmetry in the velocity distribution function.
THE INTERRELATION BETWEEN INCOMPRESSIBLE STRIPS AND QUANTIZED HALL PLATEAUS
Authors: SIDDIKI AFIF , GERHARDTS ROLF R.
Published: April 2005

We study the current and charge distribution of a two dimensional electron gas under strong perpendicular magnetic fields within the linear response regime. We show within a self-consistent screening theory that incompressible strips with integer values of local Landau-level filling factor exist for finite intervals of the magnetic field strength B. Within an essentially local conductivity model, we find that the current density in these B intervals is confined to the incompressible strips of vanishing local longitudinal resistivity. This leads to vanishing longitudinal and exactly quantized Hall resistance, and to a nice agreement of the calculated Hall potential profiles with the measured ones.
QUASIPARTICLE INTERACTIONS IN FRACTIONAL QUANTUM HALL SYSTEMS
Authors: WOJS A. , YI K.-S. , QUINN J. J.
Published: April 2005

A partially filled shell (Landau level) of Laughlin quasiparticles (QP's) gives rise to an incompressible daughter state if the QP's themselves are Laughlin correlated. This occurs only if the pseudopotential V QP (L′) describing the interaction energy of a QP pair as a function of the total pair angular momentum L′ satisfies special conditions. V QP (L′) can be obtained quite accurately from numerical studies of small systems. It does not always satisfy these conditions (e.g. for quasielectrons of the Laughlin ν=1/3 state at their ν QE =1/3 filling). In such cases, formation of pairs or larger clusters may explain the recently observed incompressible states (like ν=4/11).
LOCAL ELECTRON DENSITY PROFILE NEAR THE SAMPLE BOUNDARY INVESTIGATED BY MAGNETO-CAPACITANCE IN QUANTUM HALL REGIME
Authors: OTO K. , KIMURA M. , MIWA Y.
Published: April 2005

The spatial profiles of the electron density near the edge of narrow wires made from GaAs / AlGaAs heterostructure have been investigated using magneto-capacitance measurements in quantum Hall conditions. With decreasing the wire width below one micron, the profile of the electron density becomes steep and the electron density decreases due to the confinement potential at the boundaries of the wire. The extent of the depletion region and the local electron density near the wire edge is strongly influenced by the wire width, especially in sub-micron wires. The evaluation techniques of the local electron density profile near the edge are discussed in detail.
RECOMBINATION OF FRACTIONALLY CHARGED EXCITONS IN QUANTUM HALL SYSTEMS
Authors: QUINN J. J. , WOJS A. , YI K.-S.
Published: April 2005

Fractionally charged excitons (FCX's) consist of one or more Laughlin quasiparticles bound to a valence hole or to a negatively charged exciton. They occur when the hole is separated from the layer containing the electrons by a distance of the order of or larger than the magnetic length. The dispersion of FCX's and their importance in photoluminescence is discussed.
MAGNETIZATION OF A BILAYER 2D ELECTRON GAS
Authors: BOMINAAR-SILKENS I. M. A. , SCHAAPMAN M. R. , ZEITLER U. , CHRISTIANEN P. C. M. , MAAN J. C. , REUTER D. , WIECK A. D.
Published: April 2005

We present torque-magnetometry measurements of a bilayer two-dimensional electron gas (2DEG) with an inter-well barrier thin enough to enable a strong coupling between the quantum wells. We observe magnetization steps related to symmetric–anti-symmetric (SAS) transitions. Increasing the in-plane magnetic field leads to a reduction of the SAS splitting. Surprisingly, the heights of the magnetization steps related to Landau-level transitions are reduced relative to those measured for single-layer 2DEGs, suggesting that an in-plane magnetization component plays a role. Finally, at total filling factor ν=4, we observe an unidentified magnetization peak superposed upon the Landau-level step.
HIGH FIELD MAGNETOTRANSPORT IN STRONGLY COUPLED InAs/GaSb SUPERLATTICES
Authors: DEACON R. S. , NICHOLAS R. J. , SHIELDS P. , MASON N. J.
Published: April 2005

Vertical magnetotransport measurements are used to investigate resonant transport processes in strongly coupled InAs / GaSb superlattices. Sample I-V curves display Stark-Cyclotron resonance and longitudinal-optic (LO) phonon mediated transport features. Resonant tunnelling features change dramatically above the magnetophonon condition suggesting that the Landau levels are renormalized due to interaction between LO phonon's and electrons.
GROUND-STATE PROPERTIES OF BILAYER ν=2 QUANTUM HALL STATES
Authors: SHIMODA YUICHI , NAKAJIMA TATSUYA , SAWADA ANJU
Published: April 2005

We construct a Hartree-Fock-Bogoliubov (HFB) Hamiltonian Haldane-sphere and study excitation spectra and ground-state properties in bilayer ν=2 QH systems. It is found that the HFB approximation can systematically give SU (2) symmetrical excitation spectra spectra well agree with those from exact diagonalization calculations in large tunneling-energy region. In this region, has been considered to be a pseudospin-squeezed ground state is favored theory.
LARGE CYCLOTRON-RESONANCE LINE SPLITTING OF TWO-DIMENSIONAL ELECTRONS IN AlGaN/GaN AND AlGaAs/GaAs HETEROSTRUCTURES
Authors: SYED S. , WANG Y. J. , STORMER H. L. , MANFRA M. J. , PFEIFFER L. N. , WEST K. W. , MOLNAR R.
Published: April 2005

Large cyclotron-resonance (CR) line splittings have been observed previously in two-dimensional (2D) electrons in AlGaN / GaN and in GaAs / AlGaAs heterojunctions. The features resemble a level anti-crossing and imply a strong interaction with an unknown excitation of the solid. The origin of this phenomenon remains unexplained. This paper reviews the existing data and presents some recently detected correlations of the splitting with other sample parameters.
MODULATION OF ORDER PARAMETER OF EXCITON BOSE-EINSTEIN CONDENSATE IN A RING
Authors: YANG S.-R. ERIC , PARK Q-HAN , YEO J.
Published: April 2005

We have studied theoretically the Bose-Einstein condensation (BEC) of two-dimensional excitons in a ring with a random variation of the effective exciton potential along the circumference. We derive a nonlinear Gross-Pitaevkii equation (GPE) for such a condensate, which is valid even in the presence of a weak magnetic field. For several types of the random potentials our numerical solution of the ground state of the GPE displays a necklace-like structure. This is a consequence of the interplay between the random potential and a strong nonlinear repulsive term of the GPE. We have investigated how the mean distance between modulation peaks depends on properties of the random potentials.
OPTICAL MEASUREMENT OF MINIBAND DISPERSION AND BANDGAP RENORMALIZATION IN MODULATION-DOPED AlGaAs/GaAs SUPERLATTICES
Authors: OLIVEIRA R. F. , HENRIQUES A. B. , LAMAS T. E. , QUIVY A. A.
Published: April 2005

Doped superlattices of GaAs / Al 0.21 Ga 0.79 As composition, with a carrier concentration of n=1.4×1012 cm -2 and n=1.7×1012 cm -2 per superlattice period, where studied by photoluminescence in high magnetic fields. The photoluminescence intensity at fixed photon energies showed weak oscillations. From the oscillatory photoluminescence the superlattice miniband energy width and the renormalized bandgap were deduced.
VARIABLE FREQUENCY EPR STUDIES OF A CENTERED FeIII TETRAHEDRON
Authors: STOWE ASHLEY C. , VAN TOL JOHAN , DALAL NARESH S. , COLLISON DAVID , JONES LEIGH , TABERNOR JAMES , BRECHIN EUAN K.
Published: April 2005

High frequency EPR investigations have been undertaken to gain insight into the spin environment of a novel pentanuclear Fe III cluster, [ Fe 5 O 2( OMe )2( Bta )4( BtaH )/( MeOH )5 Cl 5] ( Fe5Bta ). The elongated, centered ferric tetrahedron contains five Fe III ions with a S =15/2 ground spin state. Variable temperature EPR suggests that the first paramagnetic excited spin state is low lying. Employing high frequencies and fields in the EPR experiments allows for resolution of g anisotropy of the Fe III centers. We therefore are able to determine the g value of the Fe III ion precisely.
SPIN STRUCTURES IN INHOMOGENEOUS FRACTIONAL QUANTUM HALL SYSTEMS
Authors: VÝBORNÝ KAREL , PFANNKUCHE DANIELA
Published: April 2005

Transitions between spin polarized and spin singlet incompressible ground state of quantum Hall systems at filling factor 2/3 are studied by means of exact diagonalization with eight electrons. We observe a stable exactly half–polarized state becoming the absolute ground state around the transition point. This might be a candidate for the anomaly observed during the transition in optical experiments. The state reacts strongly to magnetic inhomogeneities but it prefers stripe–like spin structures to formation of domains.
QUANTIFICATION OF CHONDROCYTE MORPHOLOGY BY CONFOCAL ARTHROSCOPY
Authors: Jones C. W. , Smolinski D. , Wu J. P. , Willers C. , Miller K. , Kirk T. B. , Zheng M. H.
Published: April 2005

The purpose of this study was to determine the effectiveness of a novel Laser Scanning Confocal Arthroscope (LSCA) for the morphological quantification of articular cartilage chondrocytes.

Healthy and debrided regions of the knee articular cartilage of six (6) New Zealand White rabbits were imaged during open follow-up surgery. Quantitative morphological analysis of chondrocyte cell populations was performed and compared to known parameters. Optical histology images were compared to conventional histology of similar sites.

Optical histology revealed viable cells in normal hyaline cartilage tissue and enabled the visualization of fibro-cartilage in defect tissue. Morphological analysis was able to characterize the in vivo two-dimensional equivalent-area-diameter of chondrocytes. Significant differences (P<0.05) were seen between the morphology of chondrocytes observed in optical and conventional histology.

This study concludes that the LSCA is capable of illustrating the surface and sub-surface appearance of healthy and defect articular cartilage, thereby providing a non-destructive method for assessing cartilage condition in vivo. In this role the LSCA may find application in the investigation of cartilage pathologies or repair techniques.
THE SIX FACETS MODEL: TECHNOLOGY MANAGEMENT IN THE EFFECTIVE IMPLEMENTATION OF CHANGE
Authors: KEARNS MOLLY B. , TAYLOR JAMES B. , HULL CLYDE E.
Published: April 2005

Organizational fitness is often achieved by making changes in business operations. These changes frequently involve the use of a new technology. The effective implementation of change is aided by examining the benefits and challenges of technology management when making decisions. Important elements for consideration in technology management are technology evaluation, integration, planning, implementation, training and change. A solution is proposed to combine and encompass these elements of technology management to encourage the positive aspects and avoid the negative aspects of change implementation. The tool consists of principles to be addressed for each element.
TECHNOLOGY SELECTION FROM ALTERNATIVES: A SCORING MODEL FOR SCREENING CANDIDATES IN EQUIPMENT PURCHASING
Authors: GEORGAKELLOS DIMITRIOS A.
Published: April 2005

This paper presents a technique to aid decision-making in certain technology selection projects. It describes a scoring model for screening and selecting candidates, suitable for simple cases such as equipment purchase projects. This model considers for each possible alternative its technological performance together with commercial aspects, and analyzes the results on a single "score". The main advantage of the proposed technique is that it is easy to understand and use, while not very time and effort consuming. An example of a real technology selection project from the iron and steel industry is also presented to illustrate the proposed framework.
Palaeocurrents and provenance of the Mae Rim Formation, Northern Thailand: implications for tectonic evolution of the Chiang Mai basin
Authors: Rhodes Brady P. , Conejo Richard , Benchawan Teekayu , Titus Susan , Lawson Ross
Published: April 2005

The Chiang Mai basin is the largest of a zone of rift basins that define the Northern Thailand Basin and Range Province. This province lies within the Shan Thai block of NW Indochina that extruded out of the India–Asia collision. The Mae Rim Formation crops out along the western side of the Chiang Mai basin. Detachment faults border the Mae Rim Formation on the west and north and juxtapose it against the high-grade Western Ranges metamorphic complex and its low-grade cover of Palaeozoic Shan-Thai rocks. Understanding the age and tectonic relationships between rifting, detachment faulting, ductile shear, uplift and exhumation of the Western Ranges metamorphic complex is critical to understanding the underlying deformational mechanisms that accompanied Indochina's extrusion. To better understand the palaeogeography of the Chiang Mai basin and its relationship to the Western Ranges metamorphic complex, several partial sections were measured, and palaeocurrent and clast-composition data from the Mae Rim Formation were collected. Poorly organized, immature conglomerates of the Mae Rim Formation probably represent alternating debris flows, sheet-flood, and braided channel deposits. The Mae Rim Formation probably accumulated in range-front alluvial fans, and graded rapidly into lacustrine deposits within the buried central part of the Chiang Mai basin. Except for the youngest strata, where gneissic clasts predominate, virtually all clasts in the Mae Rim Formation came from the low-grade metasedimentary rocks that form the cover of the Western Ranges metamorphic complex. Imbricated clasts indicate eastward palaeocurrents away from the metamorphic complex. Most of the Mae Rim Formation accumulated during the uplift of the Western Ranges but before erosion had breached the detachment fault. These new data suggest a tectonic history for the Chiang Mai basin that involved distinct phases of extension from late Oligocene to Quaternary, with at least two intervening periods of basin inversion.
Proposal for a terrane-based nomenclature for the Lewisian Gneiss Complex of NW Scotland
Authors: Kinny P.D. , Friend C.R.L. , Love G.J.
Published: April 2005

The current nomenclature for the Lewisian Gneiss Complex has evolved from lithological and structural correlations made prior to any dating. Initial (flawed) geochronological studies gave some names an apparent chronological standing but, as work advanced, fitting events into a coherent regional framework became increasingly difficult. Modern dating studies have shown that the Lewisian Gneiss Complex was progressively assembled from disparate blocks of Archaean continental crust and juvenile Proterozoic arcs, which satisfy the definition of terranes. Each terrane had its own separate accretionary and metamorphic history followed by a common history once juxtaposed against other terranes. Based on a new compilation of modern geochronology allied to the many detailed structural and metamorphic studies, this paper proposes a new systematic terminology for the Lewisian Gneiss Complex that is more applicable to this new tectonic framework.
The Transient Atmospheric Response to Midlatitude SST Anomalies
Authors: Ferreira David , Frankignoul Claude
Published: April 2005

To study the transient atmospheric response to midlatitude SST anomalies, a three-layer quasigeostrophic (QG) model coupled to a slab oceanic mixed layer in the North Atlantic is used. As diagnosed from a coupled run in perpetual winter conditions, the first two modes of SST variability are linked to the model North Atlantic Oscillation (NAO) and eastern Atlantic pattern (EAP), respectively, the dominant atmospheric modes in the Atlantic sector. The two SST anomaly patterns are then prescribed as fixed anomalous boundary conditions for the model atmosphere, and its transient responses are established from a large ensemble of simulations.

In both cases, the tendency of the air–sea heat fluxes to damp the SST anomalies results in an anomalous diabatic heating of the atmosphere that, in turn, forces a baroclinic response, as predicted by linear theory. This initial response rapidly modifies the transient eddy activity and thus the convergence of eddy momentum and heat fluxes. The latter transforms the baroclinic response into a growing barotropic one that resembles the atmospheric mode that had created the SST anomaly in the coupled run and is thus associated with a positive feedback. The total adjustment time is as long as 3–4 months for the NAO-like response and 1–2 months for the EAP-like one. The positive feedback, in both cases, is dependent on the polarity of the SST anomaly, but is stronger in the NAO case, thereby contributing to its predominance at low frequency in the coupled system. However, the feedback is too weak to lead to an instability of the atmospheric modes and primarily results in an increase of their amplitude and persistence and a weakening of the heat flux damping of the SST anomaly.
Shear Lag of Open and Closed Thin-walled Laminated Composite Beams
Authors: Salim Hani A. , Davalos Julio F.
Published: April 2005

Harmonic technique for shear lag analysis is extended to thin-walled open and closed composite beams. The cross section laminates are considered in isolation and are loaded by the shear flow and the axial stress resultants. In addition, the equilibrium and compatibility equations are established for each laminate and the boundary conditions at the laminate edges are satisfied. The shear lag model is incorporated into a beam model, from which the beam stiffness coefficients, shear flow, and stress resultants are obtained. Explicit shear lag formulas for various sections are developed. Composite beams are tested in bending for verification of the analytical model predictions, which agree closely with the experimental results.
Inverse Mixture Rule of Multiphase Composite Bodies
Authors: Sharma Rajesh , Ranta Sohan , Ranjan Ashish
Published: April 2005

In this paper some further bounds are given for the transverse modulus of a multiphase composite body when the stress distribution among the constituents of the composite is not uniform. A bound for the ratio of transverse modulus to the value given by the inverse mixture rule is also obtained here. The mixture is assumed to possess the properties as described in the literature.
Failure of Unidirectional-woven Composite Laminated Pin-loaded Joints
Authors: Ahn H. -S. , Kweon J. -H. , Choi J. -H.
Published: April 2005

A combined test and numerical study has been conducted for the failure analysis of unidirectional and woven composite laminated joints of an aircraft control rod. Joints with nine different geometries were tested under pin loading to evaluate the effects of the joint geometry on the failure load and mode. Nonlinear finite element analyses are performed with consideration of the contact and friction between the pin and the laminate. Failure was estimated on the characteristic curve using the Tsai-Wu and Yamada-Sun criteria. It was found that a finite element analysis based on the Tsai-Wu failure criterion with a friction coefficient of 0.1 most accurately predicts the failure load and mode of the joints.
Effect of Jet Design on Commingling of Glass/Nylon Filaments
Authors: Alagirusamy R. , Ogale Vinayak , Vaidya Abhijeet , Subbarao P. M.V.
Published: April 2005

In this study, a computational fluid dynamics (CFD) model is applied to study the airflow patterns inside the commingling jets, for different configurations. The CFD package, FLUENT 6.1, is used to predict the two-dimensional flow field inside a yarn channel. The parameters viz. velocity profile, pressure gradient, and air particle trajectory, obtained from this CFD analysis give important information for further analysis. The design parameters of commingling jets are related to the flow characteristics and their effect on the structure and properties of Glass/Nylon commingled yarns. The results show that the number of air orifice and the angle of orifice have significant effect on the airflow profile inside the jet and consequently on the structure of the commingled yarns. The jet orifice angle affects the axial velocity. The effect of air pressure is also important, since the nip frequency of commingled yarns is a function of the speed of rotation of the vortex and it is observed that with increase in air pressure, axial and tangential velocities in the nozzle increase. This work shows that, the CFD modeling can be used to optimize nozzle design parameters to develop commingled yarns with better properties.
‘Time has passed since you sent your letter’: Letter Phraseology in 1 and 2 Maccabees
Authors: Nisula Timo
Published: April 2005

This article studies how Greek letter phraseology is used in the extensive array of letter texts in 1 and 2 Maccabees. In general, letter phraseology serves the purpose of underlining the reliability of the texts concerned. It is shown that the letter texts point to a good knowledge of Greek epistolary conventions, not only on a basic phraseological level (salutations and other formulae) but also in using more sophisticated means of Hellenistic epistolography (phraseology of friendship, recommendation rhetoric). It is also suggested that some peculiar formulations in the letter of Antiochus IV in 2 Maccabees 9 are due to conscious stylistic considerations by the author of 2 Maccabees.
Achieving Downsizing
Authors: Noronha Ernesto , D’Cruz Premilla
Published: April 2005

The restructuring of organizations through downsizing is a significant phenomenon in the contemporary global business scenario. But academic research on the subject has focused limited attention on important stakeholder group, namely, the managers implementing the programmes. The article reports a qualitative study of managers in an Indian firm. Thematic analyses of narratives pointed out that managers’ experiences comprise three core themes which included the objective aspect of the experience (events, processes, tasks, outcomes), the subject component (opinions, perceptions, feelings) and coping. Linkages among these themes and their sub-themes provide a conceptual basis for further research.