bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of Epstein-Barr Virus RK-BARF0-Interacting Proteins and Characterization of Expression Pattern
Authors: Thornburg Natalie J. , Kusano Shuichi , Raab-Traub Nancy
Published: November 2004

The Epstein-Barr virus (EBV) BamHI A transcripts are a family of transcripts that are differentially spliced and can be detected in multiple EBV-associated malignancies. Several of the transcripts may encode proteins. One transcript of interest,
RK-BARF0
, is proposed to encode a 279-amino-acid protein with a possible endoplasmic reticulum-targeting sequence. In this study, the properties of RK-BARF0 were examined through identification of cellular-interacting proteins through yeast two-hybrid analysis and characterization of its expression in EBV-infected cells and tumors. In addition to the interaction previously identified with cellular Notch, it was determined that RK-BARF0 also bound cellular human I-mfa domain-containing protein (HIC), epithelin, and scramblase. An interaction between RK-BARF0 and Notch or epithelin induced proteasome-dependent degradation of Notch and epithelin but not of HIC or scramblase. Low levels of endogenous Notch expression in EBV-positive cell lines may correlate with RK-BARF0 expression. However, a screen of EBV-positive cell lines and tumors with an affinity-purified α-RK-BARF0 antiserum did not consistently detect RK-BARF0. These data suggest that while RK-BARF0 may have important cellular functions during EBV infection, and while the phenotype of EBV-positive cells suggest its expression, RK-BARF0 levels may be too low to detect.
Adenovirus VA1 Noncoding RNA Can Inhibit Small Interfering RNA and MicroRNA Biogenesis
Authors: Lu Shihua , Cullen Bryan R.
Published: November 2004

Although inhibition of RNA interference (RNAi) by plant virus proteins has been shown to enhance viral replication and pathogenesis in plants, no viral gene product has as yet been shown to inhibit RNAi in vertebrate cells. Here, we present evidence demonstrating that the highly structured ∼160-nucleotide adenoviral VA1 noncoding RNA can inhibit RNAi at physiological levels of expression. VA1, which is expressed at very high levels in adenovirus-infected cells, potently inhibited RNAi induced by short hairpin RNAs (shRNAs) or human microRNA precursors but did not affect RNAi induced by artificial short interfering RNA duplexes. Inhibition appeared to be due both to inhibition of nuclear export of shRNA or premicro-RNA precursors, competition for the Exportin 5 nuclear export factor, and inhibition of Dicer function by direct binding of Dicer. Together, these data argue that adenovirus infection can result in inhibition of RNAi and identify VA1 RNA as the first viral gene product able to inhibit RNAi in human cells.
Recombinant Human Metapneumovirus Lacking the Small Hydrophobic SH and/or Attachment G Glycoprotein: Deletion of G Yields a Promising Vaccine Candidate
Authors: Biacchesi Stéphane , Skiadopoulos Mario H. , Yang Lijuan , Lamirande Elaine W. , Tran Kim C. , Murphy Brian R. , Collins Peter L. , Buchholz Ursula J.
Published: November 2004

Human metapneumovirus (HMPV) has recently been identified as a significant cause of serious respiratory tract disease in humans. In particular, the emerging information on the contribution of HMPV to pediatric respiratory tract disease suggests that it will be important to develop a vaccine against this virus for use in conjunction with those being developed for human respiratory syncytial virus and the human parainfluenza viruses. A recently described reverse genetic system (S. Biacchesi, M. H. Skiadopoulos, K. C. Tran, B. R. Murphy, P. L. Collins, and U. J. Buchholz, Virology 321:247-259, 2004) was used to generate recombinant HMPVs (rHMPVs) that lack the G gene, the SH gene, or both. The ΔSH, ΔG, and ΔSH/G deletion mutants were readily recovered and were found to replicate efficiently during multicycle growth in cell culture. Thus, the SH and G proteins are not essential for growth in cell culture. Apart from the absence of the deleted protein(s), the virions produced by the gene deletion mutants were similar by protein yield and gel electrophoresis protein profile to wild-type HMPV. When administered intranasally to hamsters, the ΔG and ΔSH/G mutants replicated in both the upper and lower respiratory tracts, showing that HMPV containing F as the sole viral surface protein is competent for replication in vivo. However, both viruses were at least 40-fold and 600-fold restricted in replication in the lower and upper respiratory tract, respectively, compared to wild-type rHMPV. They also induced high titers of HMPV-neutralizing serum antibodies and conferred complete protection against replication of wild-type HMPV challenge virus in the lungs. Surprisingly, G is dispensable for protection, and the ΔG and ΔSH/G viruses represent promising vaccine candidates. In contrast, ΔSH replicated somewhat more efficiently in hamster lungs compared to wild-type rHMPV (20-fold increase on day 5 postinfection). This indicates that SH is completely dispensable in vivo and that its deletion does not confer an attenuating effect, at least in this rodent model.
Epitope Determinants of a Chimpanzee Fab Antibody That Efficiently Cross-Neutralizes Dengue Type 1 and Type 2 Viruses Map to Inside and in Close Proximity to Fusion Loop of the Dengue Type 2 Virus Envelope Glycoprotein
Authors: Goncalvez Ana P. , Purcell Robert H. , Lai Ching-Juh
Published: November 2004

The epitope determinants of chimpanzee Fab antibody 1A5, which have been shown to be broadly reactive to flaviviruses and efficient for cross-neutralization of dengue virus type 1 and type 2 (DENV-1 and DENV-2), were studied by analysis of DENV-2 antigenic variants. Sequence analysis showed that one antigenic variant contained a Gly-to-Val substitution at position 106 within the flavivirus-conserved fusion peptide loop of the envelope protein (E), and another variant contained a His-to-Gln substitution at position 317 in E. Substitution of Gly
106
Val in DENV-2 E reduced the binding affinity of Fab 1A5 by approximately 80-fold, whereas substitution of His
317
Gln had little or no effect on antibody binding compared to the parental virus. Treatment of DENV-2 with β-mercaptoethanol abolished binding of Fab 1A5, indicating that disulfide bridges were required for the structural integrity of the Fab 1A5 epitope. Binding of Fab 1A5 to DENV-2 was competed by an oligopeptide containing the fusion peptide sequence as shown by competition enzyme-linked immunosorbent assay. Both DENV-2 antigenic variants were shown to be attenuated, or at least similar to the parental virus, when evaluated for growth in cultured cells or for neurovirulence in mice. Fab 1A5 inhibited low pH-induced membrane fusion of mosquito C6/36 cells infected with DENV-1 or DENV-2, as detected by reduced syncytium formation. Both substitutions in DENV-2 E lowered the pH threshold for membrane fusion, as measured in a fusion-from-within assay. In the three-dimensional structure of E, Gly
106
in domain II and His
317
in domain III of the opposite E monomer were spatially close. From the locations of these amino acids, Fab 1A5 appears to recognize a novel epitope that has not been mapped before with a flavivirus monoclonal antibody.
Immunogenicity and Protection Efficacy of Replication-Deficient Influenza A Viruses with Altered NS1 Genes
Authors: Ferko Boris , Stasakova Jana , Romanova Julia , Kittel Christian , Sereinig Sabine , Katinger Hermann , Egorov Andrej
Published: November 2004

We explored the immunogenic properties of influenza A viruses with altered NS1 genes (NS1 mutant viruses). NS1 mutant viruses expressing NS1 proteins with an impaired RNA-binding function or insertion of a longer foreign sequence did not replicate in murine lungs but still were capable of inducing a Th1-type immune response resulting in significant titers of virus-specific serum and mucosal immunoglobulin G2 (IgG2) and IgA, but with lower titers of IgG1. In contrast, replicating viruses elicited high titers of serum and mucosal IgG1 but less serum IgA. Replication-deficient NS1 mutant viruses induced a rapid local release of proinflammatory cytokines such as interleukin-1β (IL-1β) and IL-6. Moreover, these viruses also elicited markedly higher levels of IFN-α/β in serum than the wild-type virus. Comparable numbers of virus-specific primary CD8
+
T cells were determined in all of the groups of immunized mice. The most rapid onset of the recall CD8
+
-T-cell response upon the wild-type virus challenge was detected in mice primed with NS1 mutant viruses eliciting high levels of cytokines. It is noteworthy that there was one NS1 mutant virus encoding NS1 protein with a deletion of 40 amino acids predominantly in the RNA-binding domain that induced the highest levels of IFN-α/β, IL-6 and IL-1β after infection. Mice that were immunized with this virus were completely protected from the challenge infection. These findings indicate that a targeted modification of the RNA-binding domain of the NS1 protein is a valuable technique to generate replication-deficient, but immunogenic influenza virus vaccines.
Lentiviral Vectors Interfering with Virus-Induced CD4 Down-Modulation Potently Block Human Immunodeficiency Virus Type 1 Replication in Primary Lymphocytes
Authors: Pham Hang M. , Argañaraz Enrique R. , Groschel Bettina , Trono Didier , Lama Juan
Published: November 2004

CD4 down-modulation is essential for the production of human immunodeficiency virus (HIV) infectious particles. Disease progression correlates with enhanced viral induced CD4 down-modulation, and a subset of long-term nonprogressors carry viruses defective in this function. Despite multiple pieces of evidence highlighting the importance of this function in viral pathogenesis in vivo, to date, HIV-induced CD4 down-modulation has not been used as a target for intervention. We describe here HIV-based vectors that deliver truncated CD4 molecules resistant to down-modulation by the viral products Nef and Vpu. Infection of cells previously transduced with these vectors proceeded normally, and viral particles were released in normal amounts. However, the infectivity of the released virions was reduced 1,000-fold. Lentiviral vectors expressing truncated CD4 molecules were efficient at blocking HIV-1 infectivity and replication in several cell lines and in CD4-positive primary lymphocytes. The findings presented here provide proof-of-principle that approaches targeting the virus-induced CD4 down-modulation may constitute the basis for novel anti-HIV therapies.
Requirement of Heat Shock Protein 90 for Human Hepatitis B Virus Reverse Transcriptase Function
Authors: Hu Jianming , Flores Dafna , Toft David , Wang Xingtai , Nguyen David
Published: November 2004

The initiation of reverse transcription and nucleocapsid assembly in hepatitis B virus (HBV) depends on the specific recognition of an RNA signal (the packaging signal, ε) on the pregenomic RNA (pgRNA) by the viral reverse transcriptase (RT). RT-ε interaction in the duck hepatitis B virus (DHBV) was recently shown to require the molecular chaperone complex, the heat shock protein 90 (Hsp90). However, the requirement for RT-ε interaction in the human HBV has remained unknown due to the inability to obtain a purified RT protein active in specific ε binding. We now report that Hsp90 is also required for HBV RT-ε interaction. Inhibition of Hsp90 led to diminished HBV pgRNA packaging into nucleocapsids in cells, which depends on RT-ε interaction. Furthermore, using truncated HBV RT proteins purified from bacteria and five purified Hsp90 chaperone factors, we have developed an in vitro RT-ε binding assay. Our results demonstrate that Hsp90, in a dynamic process that was dependent on ATP hydrolysis, facilitated RT-ε interaction in HBV, as in DHBV. Specific ε binding required sequences from both the amino-terminal terminal protein and the carboxy-terminal RT domain. Only the cognate HBV ε, but not the DHBV ε, could bind the HBV RT proteins. Furthermore, the internal bulge, but not the apical loop, of ε was required for RT binding. The establishment of a defined in vitro reconstitution system has now paved the way for future biochemical and structural studies to elucidate the mechanisms of RT-ε interaction and chaperone activation.
JNK Regulates the Release of Proapoptotic Mitochondrial Factors in Reovirus-Infected Cells
Authors: Clarke Penny , Meintzer Suzanne M. , Wang Yibing , Moffitt Lisa A. , Richardson-Burns Sarah M. , Johnson Gary L. , Tyler Kenneth L.
Published: November 2004

Reovirus-induced apoptosis is associated with activation of the proapoptotic mitogen-activated protein kinase c-Jun N-terminal kinase (JNK) and the JNK-associated transcription factor c-Jun. Here we show that reovirus-induced apoptosis and activation of caspase 3 are inhibited in cells deficient in MEK kinase 1, an upstream activator of JNK in reovirus-infected cells. Inhibition of JNK activity following reovirus infection delays the release of proapoptotic mitochondrial factors and the subsequent onset of apoptosis. In contrast, reovirus-induced apoptosis is not blocked by infection with adenovirus expressing dominant-negative c-Jun, and c-Jun activation does not correlate with apoptosis in reovirus-infected cells. This is the first report demonstrating that JNK is associated with regulation of mitochondrial pathways of apoptosis following viral infection.
Novel Replication-Incompetent Vector Derived from Adenovirus Type 11 (Ad11) for Vaccination and Gene Therapy: Low Seroprevalence and Non-Cross-Reactivity with Ad5
Authors: Holterman Lennart , Vogels Ronald , van der Vlugt Remko , Sieuwerts Martijn , Grimbergen Jos , Kaspers Jorn , Geelen Eric , van der Helm Esmeralda , Lemckert Angelique , Gillissen Gert , Verhaagh Sandra , Custers Jerome , Zuijdgeest David , Berkhout Ben , Bakker Margreet , Quax Paul , Goudsmit Jaap , Havenga Menzo
Published: November 2004

A novel plasmid-based adenovirus vector system that enables manufacturing of replication-incompetent (ΔE1) adenovirus type 11 (Ad11)-based vectors is described. Ad11 vectors are produced on PER.C6/55K cells yielding high-titer vector batches after purification. Ad11 seroprevalence proves to be significantly lower than that of Ad5, and neutralizing antibody titers against Ad11 are low. Ad11 seroprevalence among human immunodeficiency virus-positive (HIV
+
) individuals is as low as that among HIV
−
individuals, independent of the level of immune suppression. The low level of coinciding seroprevalence between Ad11 and Ad35 in addition to a lack of correlation between high neutralizing antibody titers towards either adenovirus strongly suggest that the limited humoral cross-reactive immunity between these two highly related B viruses appears not to preclude the use of both vectors in the same individual. Ad11 transduces primary cells including smooth muscle cells, synoviocytes, and dendritic cells and cardiovascular tissues with higher efficiency than Ad5. Ad11 and Ad35 appear to have a similar tropism as judged by green fluorescent protein expression levels determined by using a panel of cancer cell lines. In addition, Ad5 preimmunization did not significantly affect Ad11-mediated transduction in C57BL/6 mice. We therefore conclude that the Ad11-based vector represents a novel and useful candidate gene transfer vehicle for vaccination and gene therapy.
Mutation of All Runx (AML1/Core) Sites in the Enhancer of T-Lymphomagenic SL3-3 Murine Leukemia Virus Unmasks a Significant Potential for Myeloid Leukemia Induction and Favors Enhancer Evolution toward Induction of Other Disease Patterns
Authors: Sørensen Karina Dalsgaard , Quintanilla-Martinez Leticia , Kunder Sandra , Schmidt Jörg , Pedersen Finn Skou
Published: November 2004

SL3-3 murine leukemia virus is a potent inducer of T-lymphomas in mice. Using inbred NMRI mice, it was previously reported that a mutant of SL3-3 with all enhancer Runx (AML1/core) sites disrupted by 3-bp mutations (SL3-3dm) induces predominantly non-T-cell tumors with severely extended latency (S. Ethelberg, J. Lovmand, J. Schmidt, A. Luz, and F. S. Pedersen, J. Virol.71:7273-7280, 1997). By use of three-color flow cytometry and molecular and histopathological analyses, we have now performed a detailed phenotypic characterization of SL3-3- and SL3-3dm-induced tumors in this mouse strain. All wild-type induced tumors had clonal T-cell receptor β rearrangements, and the vast majority were CD3+CD4+CD8−T-lymphomas. Such a consistent phenotypic pattern is unusual for murine leukemia virus-induced T-lymphomas. The mutant virus induced malignancies of four distinct hematopoietic lineages: myeloid, T lymphoid, B lymphoid, and erythroid. The most common disease was myeloid leukemia with maturation. Thus, mutation of all Runx motifs in the enhancer of SL3-3 severely impedes viral T-lymphomagenicity and thereby discloses a considerable and formerly unappreciated potential of this virus for myeloid leukemia induction. Proviral enhancers with complex structural alterations (deletions, insertions, and/or duplications) were found in most SL3-3dm-induced T-lymphoid tumors and immature myeloid leukemias but not in any cases of myeloid leukemia with maturation, mature B-lymphoma, or erythroleukemia. Altogether, our results indicate that the SL3-3dm enhancer in itself promotes induction of myeloid leukemia with maturation but that structural changes may arise in vivo and redirect viral disease specificity to induction of T-lymphoid or immature myeloid leukemias, which typically develop with moderately shorter latencies.
Detection and Analysis of Six Lizard Adenoviruses by Consensus Primer PCR Provides Further Evidence of a Reptilian Origin for the Atadenoviruses
Authors: Wellehan James F. X. , Johnson April J. , Harrach Balázs , Benkö Mária , Pessier Allan P. , Johnson Calvin M. , Garner Michael M. , Childress April , Jacobson Elliott R.
Published: November 2004

A consensus nested-PCR method was designed for investigation of the DNA polymerase gene of adenoviruses. Gene fragments were amplified and sequenced from six novel adenoviruses from seven lizard species, including four species from which adenoviruses had not previously been reported. Host species included Gila monster, leopard gecko, fat-tail gecko, blue-tongued skink, Tokay gecko, bearded dragon, and mountain chameleon. This is the first sequence information from lizard adenoviruses. Phylogenetic analysis indicated that these viruses belong to the genus
Atadenovirus
, supporting the reptilian origin of atadenoviruses. This PCR method may be useful for obtaining templates for initial sequencing of novel adenoviruses.
Oncogenicity of Virulent Marek's Disease Virus Cloned as Bacterial Artificial Chromosomes
Authors: Petherbridge Lawrence , Brown Andrew C. , Baigent Susan J. , Howes Ken , Sacco Melanie A. , Osterrieder Nikolaus , Nair Venugopal K.
Published: November 2004

Marek's disease virus (MDV) is an oncogenic alphaherpesvirus that induces T-cell lymphomas in poultry. We report the construction of bacterial artificial chromosome (BAC) clones of the highly oncogenic RB-1B strain by inserting mini-F vector sequences into the U
S
2 locus. MDV reconstituted from two BAC clones induced rapid-onset lymphomas similar to those induced by the wild-type virus. Virus reconstituted from another BAC clone that showed a 7.7-kbp deletion in the internal and terminal unique long repeat regions was nononcogenic, suggesting that the deleted region may be associated with oncogenicity. The generation of the oncogenic BAC clones of MDV is a significant step in unraveling the oncogenic determinants of this virus.
A TYPE-FREE THEORY OF HALF-MONOTONE INDUCTIVE DEFINITIONS
Authors: KAMEYAMA YUKIYOSHI
Published: November 2004

This paper studies an extension of inductive definitions in the context of a type-free theory. It is a kind of simultaneous inductive definition of two predicates where the defining formulas are monotone with respect to the first predicate, but not monotone with respect to the second predicate. We call this inductive definition half-monotone in analogy of Allen’s term half-positive.

We can regard this definition as a variant of monotone inductive definitions by introducing a refined order between tuples of predicates. We give a general theory for half-monotone inductive definitions in a type-free first-order logic. We then give a realizability interpretation to our theory, and prove its soundness by extending Tatsuta’s technique. The mechanism of half-monotone inductive definitions is shown to be useful in interpreting many theories, including the Logical Theory of Constructions, and Martin-Löf’s Type Theory. We can also formalize the provability relation “a term p is a proof of a proposition P” naturally. As an application of this formalization, several techniques of program/proof-improvement can be formalized in our theory, and we can make use of this fact to develop programs in the paradigm of Constructive Programming. A characteristic point of our approach is that we can extract an optimization program since our theory enjoys the program extraction theorem.
OBSERVING DISTRIBUTION IN PROCESSES: STATIC AND DYNAMIC LOCALITIES
Authors: CASTELLANI ILARIA
Published: November 2004

The distributed structure of CCS processes can be made explicit by assigning different locations to their parallel components. These locations then become part of what is observed of a process. The assignment of locations may be done statically, or dynamically as the execution proceeds. The dynamic approach was developed first, in Refs. [4,5], as it appeared to be more convenient for defining notions of location equivalence and preorder. Extending previous work by L. Aceto1 we study here the static approach, which is more natural from an intuitive point of view, and more manageable for verification purposes. We define static notions of location equivalence and preorder, and show that they coincide with the dynamic ones. To establish the equivalence of the two location semantics, we introduce an intermediate transition system called occurrence system, which incorporates both notions of locality. This system supports a definition of local history preserving bisimulation for CCS, which is a third formulation of location equivalence.
HOW TO SIMULATE TURING MACHINES BY INVERTIBLE ONE-DIMENSIONAL CELLULAR AUTOMATA
Authors: DUBACQ JEAN-CHRISTOPHE
Published: November 2004

The issue of testing invertibility of cellular automata has been often discussed. Constructing invertible automata is very useful for simulating invertible dynamical systems, based on local rules. The computation universality of cellular automata has long been positively resolved, and by showing that any cellular automaton could be simulated by an invertible one having a superior dimension, Toffoli proved that invertible cellular automaton of dimension d≥2 were computation-universal. Morita proved that any invertible Turing Machine could be simulated by a one-dimensional invertible cellular automaton, which proved computation-universality of invertible cellular automata. This article shows how to simulate any Turing Machine by an invertible cellular automaton with no loss of time and gives, as a corollary, an easier proof of this result.
EFFECT OF AN INTRAPERITONEAL INJECTION OF Ca-DTPA AND Zn-DTPA ON ESSENTIAL TRACE METAL CONCENTRATIONS IN RAT PLASMA
Authors: SATO I. , MATSUSAKA N. , KOBAYASHI H. , SUZUKI T. , SERA K. , FUTATSUGAWA S. , NISHIMURA Y.
Published: November 2004

Ca-DTPA and Zn-DTPA were injected intraperitoneally into rats with a dose of 30 or 300 µmol/kg. The blood was collected from the tail vein just before the injection, 3, 6 and 24 hours after the injection. and centrifuged 10 separate the plasma. These plasma samples were analyzed by PIXE at Nishina Memorial Cyclotron Center.

Sodium, potassium, calcium, iron, copper and zinc were detected in the plasma. Ca-DTPA significantly lowered the concentration of zinc, while no significant changes were observed in the other metals. Zn-DTPA did not lower any metal concentrations, but a significant increase of plasma zinc was observed.

In conclusion, Ca-DTPA was confirmed to induce hypozincemia, which may be the cause of fetal injuries such as abortion, fetal death and malformation. Zn-DTPA was suggested not to induce any deficiencies of essential metals.
DETERMINATION OF INDIUM CONCENTRATION IN SEMICONDUCTOR OF GaAs BY PIXE
Authors: IZAWA G. , YONENAGA I.
Published: November 2004

Concentration of In impurity doped in GaAs semiconductor was determined by PIXE method non-destructively using a plate target. The concentration of In in the range from 0.05 to 1 wt.% in GaAs crystals is given from PIXE peak intensities by [In] (wt.%)=(0.39±0.06)×In Kα/ (Ga Kβ+As Kα).
DISTRIBUTION OF ELEMENTS IN BEAN SPROUT DETERMINED BY PIXE ANALYSIS
Authors: Yukawa Masae , Kimura Ayami , Watanabe Yoshito , Sakurai Shiro
Published: November 2004

Soybean is one of the major crops in the world as a source of protein. Spatial distribution of elements in bean sprout, soybean seedling, was determined by Particle Induced X-ray Emission (PIXE) analysis to investigate their transfer in the growth. Soybeans were germinated in a dark box at 25~26ºC using pure water without any mineral supplement. After 20hr, 40hr, 65hr and 137hr, the seedlings were harvested and each sprout was separated into cotyledons, hypocotyls, leaves and root. Each part of bean sprout was freeze-dried and applied to PIXE analysis. It was observed that K, Mn, Fe, Cu and Zn moved from the cotyledons and the primary root to the hypocotyls and the 1st leaf, while Ca in the seed hardly moved to other part.
CHANGES OF BLOOD PLASMA ELEMENT CONTENTS IN X-RAY IRRADIATED MICE BY PIXE ANALYSIS
Authors: TAMANOI ITSURO , NAKAMURA AKEMI , HOSHIKAWA KIYOFUSA , KACHI MUTSUMI , GOTO BUNSHIRO , JOSHIMA HISAMASA , MATSUMOTO SHINJI
Published: November 2004

The quantitative changes of elements in blood plasma were observed with the passage of time after X-ray whole body irradiation with 12 Gy on C57BL/6J mice by PIXE method. From 4 days after irradiation, dead mouse was found and all mice died by 8 days. Hematocrit (Ht) values indicated a decrease from the 1st day, but on days 3 and 4 there was a small rise. Finally the values became 64 % of that of non-irradiated control on day 7, it was just before death. By analysis with PIXE method, 15 elements were observable in blood plasma of control mice. The elements such as P, S, Cl, K, Ca and Cr were abundant and Fe and Br followed. As trace elements, the peaks of Zn, Cu and Ni were clearly observed. After irradiation, K and Ca decreased on day 1st, afterwards increased gradually. On the contrary, the elements, S, Cl, were rather stable. While Fe decreased from 1st day, Cu increased from the day 2. Zn and Ni showed intensely down and rise in amount, and decreased on day 7. The results of possible measurement of the changes in amount of these elements of blood plasma suggest PIXE method is an easy and useful way for diagnosis.
Elemental Concentrations of Atmospheric Aerosols: Seasonal and Daily Changes
Authors: Kasahara M. , Gotoh N.
Published: November 2004

The micro-analytical technique has made remarkable progress during the last two to three decades. A Particle Induced X-ray Emission(PIXE) is one of the most powerful analytical method. The analysis of atmospheric aerosol is one of the most preferable fields of the PIXE analysis. Applying the PIXE analysis, we have investigated the characteristics of atmospheric aerosols under the various environmental and meteorological conditions. The atmospheric aerosols were continuously sampled every 12 hours for one year from October 1992 to October 1993. The concentrations of gravimetric mass and 15 elements were determined by a microbalance method and the PXIE analysis.respectively.

The seasonal change of mass concentration of atmospheric aerosols has commonly two peaks in spring and early winter. The peak in spring is mainly caused by the Kosa dust. The most dominant element was Si and S the coarse and fine particles,respectively. Daily change of elemental concentrations differed according to the origin of each element and the scavenging effect of atmospheric aerosols by rain drops was clearly observed in the time variation of aerosol concentration.
HIGH RESOLUTION L X-RAY EMISSION SPECTRA OF Fe AND Cu INDUCED BY O.75 MeV/u ION IMPACT
Authors: KAGEYAMA H. , TAKAHASHI R. , HAMAGUCHI D. , AWATA T. , NAKAE T. , NISHIHATA A. , KAWATSURA K. , ARAI S. , AOKI Y. , YAMAMOTO S. , TAKESHITA H. , GOPPELT-LANGER P. , NARAMOTO H. , KAMBARA T. , OURA M. , PAPP T. , KANAI Y. , AWAYA Y. , HORINO Y. , MOKUNO Y. , CHAYAHARA A. , KINOMURA A. , TSUBOUCHI N. , FUJII K.
Published: November 2004

High resolution L x-ray emission spectra of Fe and Cu have been measured by 0.75 MeV/u H and He, and 0.73 MeV/u He, Si and Ar ion impacts with a crystal spectrometer. The x-ray transition energies in the Fe and Cu targets for Lι, Lη, Lα1,2, Lβ1 and Lβ3,4 diagram lines induced by light ion impacts are determined, which are in good agreement with those given in the reference. The difference in L x-ray emission spectra produced by H, He, Si and Ar ions is considered and the emission spectra for the Cu target are compared with the calculated ones based on the multiconfiguration Dirac-Fock method. The origin of the broadening of the Lα1,2 line to the lower energy for Si and Ar ion impacts is attributed to one 2p plus one 3d electron vacancy production.
THE NEW LOW ENERGY ION BEAM ANALYSIS FACILITY AT MAPUTO UNIVERSITY
Authors: UTUI R.J. , HOMMAN N.P.O. , MALMQVIST K.G.
Published: November 2004

A new Ion Beam Analysis (IBA) facility which was recently installed in the Department of Physics of the Eduardo Mondlane University of Maputo, Mozambique, is described. The set up is based on a low energy (500 keV) Van de Graaff proton accelerator and is intended to be used in particle induced X-ray emission (PIXE), Rutherford Backscattering (RBS) and nuclear reaction analysis (NRA).

Preliminary experiments on beam diagnostics were performed successfully and the followed procedure is described.
ENPASSANT: AN ENVIRONMENT FOR EVALUATING MASSIVELY PARALLEL ARRAY ARCHITECTURES FOR SPATIALLY MAPPED APPLICATIONS
Authors: HERBORDT MARTIN C. , WEEMS CHARLES C.
Published: November 2004

Although massively parallel arrays for spatially mapped applications have been proposed since the 1950s42 and built since the 1960s,12 there have been very few systematic empirical studies that cover more than a small fraction of the design space. The problems have included the lack of a test suite of non-trivial application codes; inadequate language support; the difficulties of balancing evaluation performance with flexibility; and balancing test suite portability with accuracy of evaluation. We describe an environment that addresses these problems. A realistic workload including a series of applications currently being used as building blocks in vision research has been constructed. Both flexibility in architectural parameter selection and simulation efficiency are maintained with a novel new technique that combines virtual machine emulation with trace-driven simulation. The trade-off between fairness to diverse target architectures and programmability of the test suite is addressed through the use of operator and application libraries for a small set of critical functions. We also present examples of the type of results we are obtaining, including the effects of changing ALU designs and datapath widths, finding critical points in register set and cache sizes, the benefits of various types of router networks, and the performance cost of processor virtualization.
A VLSI PARALLEL ARCHITECTURE FOR FUZZY EXPERT SYSTEMS
Authors: CATANIA V. , ASCIA G.
Published: November 2004

In this paper we present a VLSI fuzzy processor whose main features are a scalable parallel architecture, and the computation of fuzzy inferences based on the α-level set theory, both of which are important in the field of intensive fuzzy computing, as in fuzzy expert systems. A specific analysis is made in the paper, of techniques for the representation of fuzzy sets, in relation to the amount of area occupied and the forms they can assume. From this analysis a solution is extracted and then used for the processor presented in the paper.

The architecture of the processor is chosen after the assessment of possible alternatives by analyzing an appropriate probabilistic model. The processor comprises a set of units which work parallelly and asynschronously to process the various rules. The structure is easy to scale up, as an increase in the number of processing units does not produce bottlenecks in performance. The performance obtainable is about 310 KFLIPS, with a clock frequency of 60 Mhz, 8 input variables, either crisp or fuzzy, and an 8-bit resolution.
A TIME-OPTIMAL MULTIPLE-QUERY NEAREST-NEIGHBOR ALGORITHM ON MESHES WITH MULTIPLE BROADCASTING
Authors: STOICA ION
Published: November 2004

The multiple-query nearest-neighbor (MQNN) problem is stated as follows: given a set S of n points in plane and a set Q of m(1≤m≤n) query points, determine for every point in Q its closest neighbor in S. Besides the pure theoretical interest, this problem has many practical applications in various areas such as: computer graphics, pattern recognition and image processing. First, this paper proposes a new time-optimal algorithm to solve the all nearest-neighbor (ANN) problem in [Formula: see text] time on a mesh-connected computer of size [Formula: see text]. Next, using this result in conjunction with the generalized multiple search (GMS) paradigm of Bokka et al.3,5 we devise a time-optimal algorithm that solves the MQNN problem in [Formula: see text] time on a mesh with multiple broadcasting (MMB) of size [Formula: see text].
A NEW 26-CONNECTED OBJECTS SURFACE TRACKING ALGORITHM AND ITS RELATED PRAM VERSION
Authors: PERROTON LAURENT
Published: November 2004

In this paper, we show the interest of the 3D discrete surface notion for the extraction of object contours. We introduce some notions related to surfaces of 18-and 26-connected objects in 3D discrete images, and a new sequential algorithm to extract the surface and contours of 26-connected objects. Then, we present a PRAM related algorithm to construct the successor function of the surface graph. The complexity of the algorithm is O(log N) for an N×N×N image, with N3 processors.
POST-EDITING THROUGH APPROXIMATION AND GLOBAL CORRECTION
Authors: TAGHVA KAZEM , BORSACK JULIE , BULLARD BRYAN , CONDIT ALLEN
Published: November 2004

This paper describes a new automatic spelling correction program to deal with OCR generated errors. The method used here is based on three principles:

1. Approximate string matching between the misspellings and the terms occuring in the database as opposed to the entire dictionary

2. Local information obtained from the individual documents

3. The use of a confusion matrix, which contains information inherently specific to the nature of errors caused by the particular OCR device

This system is then utilized to process approximately 10,000 pages of OCR generated documents. Among the misspellings discovered by this algorithm, about 87% were corrected.
PROJECTION OF MULTI-WORDED LEXICAL ENTITIES IN AN INFLECTIONAL LANGUAGE
Authors: SENGUPTA P. , CHAUDHURI B.B.
Published: November 2004

A formalism for lexical projection in a Lexical Functional Grammar based syntactic processing environment, where lexical items may consist of more than one word, has been discussed. It is an extension of an earlier formalism that assumed single-worded lexical entities. It has been shown that traditional approaches of handling multi-worded lexical entities in an LFG environment are not quite suitable for Bangla, the language under study, because these approaches assume configurationality whereas Bangla is non-configurational. A “Supra-Lexical” level of analysis has been proposed and a formalism for such analyses introduced. The proposed formalism consists of two phases—an off-line specification phase and an implementation phase. Some tools that are required, along with the syntax for supra-lexical specification has been introduced with examples. Compilation of the specifications has been discussed.
ASSESSMENT OF BLEEDING PREDISPOSITIONS IN TONSILLECTOMY/ADENOIDECTOMY PATIENTS USING NON-METRIC CLUSTERING
Authors: GORDON HEATHER , PIZZI NICOLINO J. , GERRARD JON M. , SOMORJAI RAY
Published: November 2004

A questionnaire, designed to assess bleeding predispositions in tonsillectomy and/or adenoidectomy patients, was administered to 236 otherwise healthy children. For comparative purposes, 114 patients with bleeding disorders were also studied. An unsupervised non-metric clustering technique was used in an attempt to classify bleeders against non-bleeders based solely on the responses to the questionnaire. Non-metric techniques are essential for the classification process because of the large number of missing attribute values in the patient data set. As a benchmark, a supervised inductive machine learning strategy was also used to classify the patients.

Performance results are compared and contrasted between the techniques across different subsets of the patient data. These techniques are also evaluated as a methodology for determining the relative significance of attributes vis-à-vis the reduction of the dimensionality of a large medical data set. In this investigation, the classification rate achieved using the non-metric technique (73%) was only marginally poorer than the rate using the supervised technique (76%). Moreover, these results were obtained with an accompanying 80% reduction in the number of attributes used to perform the analysis.
A FAST AND EFFECTIVE OCCLUSION DETECTION ALGORITHM
Authors: CHING WEE-SOON
Published: November 2004

Occlusion detection is an important problem in 3D computer vision which uses multiple views, such as stereo vision. The presence of occlusion complicates the problem of vergence and the subsequent stereo matching in the generation of 3D data. This paper presents an approach which detects the presence of occlusion concurrently during the vergence process. The main limitation of the approach where the maximum correlation coefficient can be very high even when a significant amount of occlusions is present in the stereo images is shown. This paper presents an adaptive method of adjusting the correlation threshold with respect to the contrast-levels of the image being analyzed to alleviate this limitation. The proposed adaptive threshold method ensures that the sensitivity of detecting mismatches is less dependent upon the contrast-levels of the image being analyzed. The computational advantage of the proposed adaptive threshold method over the fixed threshold method is also presented. Experimental results which show the strengths of the proposed adaptive threshold method over the fixed threshold method on real scenes are given.
CAPACITOR FLOATATION SCHEME USING ONLY OTAs AND GROUNDED CAPACITORS
Authors: ANANDA MOHAN P. V.
Published: November 2004

A circuit for realizing floating capacitors using OTAs and grounded capacitors will be presented together with a few applications.
INTERVAL ANALYSIS IN POWER ELECTRONICS
Authors: FEMIA N. , SPAGNUOLO G. , TUCCI V.
Published: November 2004

The use of Interval Analysis for numerical simulation of power electronic circuits is discussed in this paper. It is shown that Interval Analysis is an optimal tool for such kind of applications since switching circuits operate upon sequences of time intervals bounded by instants that are zeros of non-linear non-monotonic functions. The main advantages offered by Interval Analysis are pointed out in the context of a new approach proposed to solve the problems of steady-state and transient analysis. In particular, it is shown that for steady-state analysis a robust and fast IA-based method can be adopted which generates a sequence of virtual solutions that converges towards the right steady-state solution within few iterations, without any prior knowledge about the mode of operation of the circuit. Some examples of applications are proposed, including chaos, subharmonics and circuit collapse.
A COMPUTER METHOD FOR THE FORMULATION OF AVERAGED MODELS FOR DC/DC POWER CONVERTER CIRCUITS
Authors: LAI Y. M. , TSE C. K. , MEHTA P.
Published: November 2004

A computer method for deriving averaged circuit models for a class of power converter circuits is proposed. The proposed method is applicable to any dc/dc converter circuit whose switching frequency is much greater than the natural frequency of each constituent circuit topology. The method starts with decomposing the original circuit into two multiport sub-circuits. One contains the "fast" part, called the Minimum Separable Switching Configuration (MISSCO), and the other contains the remaining "slow" part of the circuit. A hybrid matrix that relates the port voltages and currents of the MISSCO to these constant sources is determined for each switching cycle. By applying one-cycle averaging operation to the hybrid matrices, the low frequency averaged model of the MISSCO is derived. This averaged model can then be combined with the rest of the circuit to form a complete equivalent circuit. For brevity we demonstrate the method in this paper for DC/DC converter circuits in the absence of parasitics. To illustrate the proposed method, the Ćuk converter is considered and its averaged model is derived for the discontinuous inductor-current mode of operation.
A NOVEL THREE-PHASE THREE-SWITCH THREE-LEVEL UNITY POWER FACTOR BOOST-TYPE PWM RECTIFIER
Authors: KOLAR JOHANN W. , ZACH FRANZ C.
Published: November 2004

Based on the combination of a three-phase diode bridge and a DC/DC boost converter a new three-phase three-switch three-level PWM rectifier system is developed. It can be characterized by sinusoidal mains current consumption, controlled output voltage and low blocking voltage stress on the power transistors. The application could be, e.g., for feeding the DC link of a telecommunications power supply module. The stationary operational behavior, the control of the mains currents and of the output voltage are analyzed. Finally, the stresses on the system components are determined by digital simulation and compared to the stresses in a conventional PWM rectifier system.
LOW VOLTAGE POWER ELECTRONICS
Authors: COBOS J. A. , GARCÍA O. , SEBASTIÁN J. , UCEDA J.
Published: November 2004

This paper summarizes some of the current solutions to fulfil the requirements of the new low voltage power systems. On one hand, microelectronics evolution demands lower supply voltage. On the other hand, the portability of the new communication systems demands lighter and smaller power electronics.

The improvement of the performance of low power and low output voltage converters is carried out in this paper. Topics like power density, efficiency, thermal management, battery life, hard and soft switching, magnetics integration, synchronous rectification and power factor correction affect each other in these kinds of converters. Although all the relations among the previous terms are difficult to assess, this paper reviews some aspects of the current situation.
MODELLING WINDING LOSSES IN HIGH-FREQUENCY POWER INDUCTORS
Authors: BARTOLI M. , NOFERI N. , REATTI A. , KAZIMIERCZUK M. K.
Published: November 2004

A high-frequency model of iron-powder-core inductors is studied. The skin and proximity effects that cause the winding parasitic resistance to increase with the operating frequency are considered. The inductor self-resonance due to the parasitic capacitances is taken into account as well. The frequency response of the inductor model is compared to that of an experimentally tested iron-powder-core inductor. Expressions giving the ac resistance as a function of the operating frequency are given. These expressions allow for an accurate prediction of the inductor power loss over a wide frequency range. The measured and calculated values of the inductor impedance magnitude and phase, the real and imaginary parts of the inductor impedance, the inductance, and the inductor quality factor are plotted versus frequency and compared. Theoretical results were in good agreement with those experimentally measured. A design procedure for solid wire winding inductors based on the results of the inductor modelling is also given in the paper.
COMPLEXITY IN AN INDUSTRIAL FLYBACK CONVERTER
Authors: BAGLIO SALVATORE , FORTUNA LUIGI , MANGANARO GABRIELE , CRISTAUDO ROSARIO
Published: November 2004

In this letter a functional model of an industrial flyback converter is introduced. Its accuracy within a defined condition range is shown. The complexity of the system is discussed by using experimental data. Moreover, it is shown that the complex dynamics of a flyback converter can be clusterized in some classes of well-known paradigms appearing in some defined canonical circuits.
MODELING AND SIMULATION OF CONVERTER SYSTEMS PART II: SIMULATION PACKAGE TCAD
Authors: SZCZESNY ROMUALD , RONKOWSKI MIECZYSLAW
Published: November 2004

The methods, models and techniques — presented in the companion paper — have been used as a basis for the evaluation of popular general-purpose electrical circuit simulation programs, in particular, their applicability in the analysis of power electronic circuits. As a result of this critical evaluation, the general requirements for the simulation program adequate for converter systems studies and design have been formulated. On this basis the algorithm of TCAD — a general-purpose converter system simulation program — has been elaborated. In presentation of the TCAD program three parties have been distinguished: the first one emphasizes the applications of modern simulation methods for converter systems, the second describes briefly the features of the main modules of the TCAD package, and the third presents some simulation examples of practical converter systems. Three simulation examples are presented: two resonant converters and an induction motor drive fed by a full-bridge voltage source PWM inverter at normal and fault operation conditions. A good agreement between simulation and experimental results has proved that this simulation package is a power tool for research, teaching and engineering practice.
IESEM: INTEGRATED ENVIRONMENT FOR SOFTWARE EVOLUTION MANAGEMENT
Authors: CANFORA GERARDO , LANUBILE FILIPPO , VISAGGIO GIUSEPPE
Published: November 2004

Software evolution has no common paradigm which practitioners can adhere to. On the contrary, there is a wide range of models, methods, techniques, and tools which are selected according to the specific task, the application domain, the professional experience, and the organizational culture. We argue that different approaches and technologies may be combined into a unique platform to satisfy the needs of software systems which evolve over long periods of time.

This paper presents the Integrated Environment for Software Evolution Management (IESEM) which includes software repositories, reverse engineering tools, rationale capture tools, software measurement tools, and a user-friendly interface. It can manage heterogeneous systems characterized by various design methods and programming languages. IESEM is based on a central repository which stores software engineering artifacts, program code, design, and implementation decisions in the form of a traceability graph. The repository stores also software measures computed both from programs and external CASE repositories. Measures are used to control software degradation during its evolution and to support decisions based on quality factors.

The key concepts of IESEM, its design, and implementation are presented. The use of IESEM during development and maintenance is discussed. A case study shows IESEM's effectiveness in performing maintenance tasks.