bluuebunny/crossref_metadata_2025 huggingface dataset:
Time resolved measurements show that phosphate release is the rate limiting step on myofibrillar ATPases
Authors: Lionne Corinne , Brune Martin , Webb Martin R. , Travers Franck , Barman Tom
Published: April 2003

The myofibril is a good model to study the ATPase of the muscle fibre. When myofibrillar ATPase reaction mixtures are quenched in acid, there is a burst of Pi formation, due to AM · ADP · Pi or Pi as shown in the scheme: AM + ATP ↔ A·M·ATP ↔ AM·ADP·Pi ↔ AM·ADP + Pi ↔ AM + ADP. Therefore, in the steady state, either AM·ADP·Pi or AM·ADP or both predominate. To determine which, we studied the reaction using a Pi binding protein (from E. coli) labeled with a fluorophore such that it is specific and sensitive to free Pi [Brune, M. et al. (1994) Biochemistry 33, 8262–8271]. We show that the Pi bursts with myofibrillar ATPases (calcium‐activated or not, or crosslinked) are due entirely to protein bound Pi. Thus, with myofibrillar ATPases the AM·ADP·Pi state predominates.
Detection of histidine‐phospho‐proteins in animal tissues
Authors: Noiman Silvia , Shaul Yosef
Published: April 2003

In this report we outline a protocol for rapid detection of histidine phosphoproteins in cellular crude extracts prepared from different tissues. The nature of the phosphorylated amino acid residues was confirmed by determination of their stability under different pH conditions and by direct phospho‐amino acid analysis. Furthermore, DEPC treatment that can selectively modify the histidine residues blocks the phosphorylation. Interestingly, the phosphoprotein pattern detected under these conditions in four different tissues is very similar, suggesting that these proteins play important roles in biochemical pathways shared by many cells and tissues.
Strand scission in DNA induced by l‐DOPA in the presence of Cu(II)
Authors: Husain Seema , Hadi S.M.
Published: April 2003

It has been recently reported that l‐DOPA and Cu(II) in the presence of H2O2 leads to extensive DNA damage. In this paper we show that l‐DOPA in the presence of Cu(II) alone can cause DNA cleavage through the generation of reactive oxygen species such as the hydroxyl radical. Fluorescence quenching studies indicate that l‐DOPA is capable of binding to DNA.
Tyrosine kinase inhibition reduces the plateau phase of the calcium increase in response to progesterone in human sperm
Authors: Bonaccorsi L. , Luconi M. , Forti G. , Baldi E.
Published: April 2003

Progesterone (P) has previously been shown to induce a rapid increase in [Ca2+]i as well as tyrosine phosphorylation of proteins in human spermatozoa. Both these effects are essential for induction of the acrosome reaction by P. We investigated a possible relationship between the P‐induced calcium increase and tyrosine kinase activation, by evaluating the effect of the tyrosine kinase inhibitor genistein on these two effects. We found that preincubation with genistein abolished P‐induced tyrosine phosphorylation of two sperm proteins of 97 and 75 kDa molecular weight and significantly inhibited the plateau phase of P‐induced [Ca2+]i increase without affecting the peak phase. Conversely, the plateau phase was enhanced by the tyrosine phosphatase inhibitor Na3VO4. The effect of genistein was specific for P, since no inhibition was observed on the [Ca2+]i increase induced by thapsigargin, an inhibitor of endoplasmic Ca2+‐ATPase previously shown to mobilize Ca2+ in spermatozoa. These results indicate that tyrosine kinase activation is involved in the generation of the plateau phase of Ca2+ influx induced by P, and suggest the possibility that two different pathways are involved in the induction of Ca2+ entry by P in human sperm.
Total antioxidant activity of low density lipoproteins and the relationship with α‐tocopherol status
Authors: Miller Nicholas J. , Paganga George , Wiseman Sheila , Van Nielen Wim , Tijburg Lilian , Chowienczyk Philip , Rice-Evans Catherine A.
Published: April 2003

A rapid method is described for measuring the antioxidant activity of low density lipoproteins. Studies were undertaken on individuals attending a hyperlipidaemia clinic, an unsupplemented group and a group after supplementation with 300 mg dl‐α‐tocopherol acetate for nine weeks. The results show a positive correlation between the antioxidant activity and α‐tocopherol content of LDL in the supplemented group.
Genomic structure of the mouse A‐type lamin gene locus encoding somatic and germ cell‐specific lamins
Authors: Nakajima Noboru , Abe Kenji
Published: April 2003

Mouse A‐type lamin genes were isolated. Structural analyses revealed that all the three known mouse A‐type lamins (A, C and C2) were coded in a single genomic locus in a 22 kilobase DNA segment. The three lamins were coded in 12, 10 and 10 exons for A, C and C2, respectively, and shared 8 exons among them. Primer extension analyses identified possible transcription start sites for both A/C and C2 genes suggesting that the locus is under the control of two separate promoters, that is a somatic cell‐acting promoter (for A and C) and a testis‐specific promoter (for C2) which resides in the first intron of the A/C gene. Sequence characteristics of the possible promoter regions are discussed. Divergence of the two somatic cell‐type lamins (A and C) is formally accounted for by differential selection of poly(A) sites together with lamin A‐specific splicing.
Mutational analysis of a putative polyphosphoinositide binding site in phospholipase C‐β2
Authors: Paula Simões A. , Camps Montserrat , Schnabel Petra , Gierschik Peter
Published: April 2003

The phosphatidylinositol 4,5‐bisphosphate (PtdInsP2)‐regulated actin‐binding protein gelsolin and most phosphoinositide‐specific phospholipases C (PLCs) comprise a basic amino acid motif ((K/R)xxxKxK(K/R); x denotes any amino acid) which was previously suggested to represent a PtdInsP2‐binding site commonly present in these proteins. We have challenged this hypothesis for PLCβ2by replacing one or several residues of this motif (KILIKNKK; residues 457–464) and examining the functional consequences of these alterations. The results show that the integrity of the basic motif is important for PtdInsP2hydrolysis by PLCβ2. Replacement of lysines 463 or 461 by arginine led to reduction or complete loss, respectively, of enzyme activity. The results provide further support to the concept that the function of the basic motif within the various PLCs is to bind the enzyme substrate PtdInsP2.
Transcriptional regulation of carbonic anhydrase II by retinoic acid in the human pacreatic tumor cell line DANG
Authors: Rosewicz Stefan , Riecken Ernst-Otto , Stier Ute
Published: April 2003

Carbonic anhydrase II (CA II) generates bicarbonate in human pancreatic duct cells. We have developed the human pancreatic duct cell line DANG as a model to study the effects of all‐trans‐retinoic acid (ATRA) on CA II gene expression. ATRA treatment resulted in a time‐ and dose‐dependent inhibition of CA II mRNA concentrations in DANG cells. These inhibitory effects were paralleled by a time‐dependent decrease of CA II protein concentrations. Nuclear run on analysis revealed that the decrease of CA II mRNA concentrations was due to a decreased rate of CA II gene transcription. These data show that ATRA transcriptionally modulates CA II gene expression in human pancreatic carcinoma cells.
Poly(arabitol phosphate) teichoic acid in the cell wall of Agromyces cerinus subsp. cerinus VKM Ac‐1340T
Authors: Shashkov Alexander S. , Streshinskaya Galina M. , Gnilozub Viktoriya A. , Evtushenko Lyudmila I. , Naumova Irina B.
Published: April 2003

On the basis of NMR studies and analysis of the products of acid and alkaline hydrolyses the following structures were established for the repeating units of poly(arabitol phosphate) teichoic acid: and . The molar ratio of these units is about 1.2:1.0, respectively. Poly(arabitol phosphate) teichoic acid is here reported in bacterial cell walls for the first time.
Lack of elevated drug efflux in adriamycin‐resistant immunoblastic B lymphoma cells with mdr1 overexpression
Authors: Chao Chuck C.-K.
Published: April 2003

A multidrug‐resistant (MDR) subline of the immunoblastic B lymphoma cell line was established by sequentially selecting in increasing concentrations of adriamycin. The adriamycin‐resistant cell line (HOB1/ADR) demonstrated resistance to a wide spectrum of chemotherapeutic agents including MDR drugs (Vinca alkaloids and anthracycline), antimicrotubule drug (colchicine), and DNA‐damaging agents (cisplatin and mitomycin C). The expression of human mdr1 gene, as analyzed by RT‐PCR and Western blotting, revealed a 13–15‐fold increase in resistant cells. Unexpectedly, HOB1/ADR cells demonstrated a lack of reduced accumulation and of enhanced efflux of adriamycin. More than 60% adriamycin was effluxed at the same rate in both cell lines within 10 min. In contrast, the initial rate of vincristine accumulation was reduced by 3 fold in this resistant cell line. The maxima level of vincristine accumulation was 50% lower in the resistant cells than the parental cells. The maximal efflux rate was enhanced by 5 fold in the resistant cells. Inhibition of vincristine resistance by verapamil associated with restoration of drug accumulation, suggesting that acquired resistance in these cells is due to P‐glycoprotein. These studies demonstrated that immunoblastic B lymphoma cells selected for adriamycin resistance preferentially developed P‐glycoprotein‐mediated vincristine efflux which plays an important role in vincristine resistance. In contrast, the resistant cells did not elevate adriamycin efflux, suggesting an additional mechanism responsible for adriamycin resistance.
The Gag polypeptides of the Drosophila 1731 retrotransposon are associated to virus‐like particles and to nuclei
Authors: Haoudi Abdelali , Kim Myeong Hee , Champion Serge , Best-Belpomme Martin , Maisonhaute Claude
Published: April 2003

1731 is a Drosophila melanogaster retrotransposon whose nucleotide sequence shows a proviral architecture with two long terminal repeats (LTRs) framing two internal Open Reading Frames (ORFs). The pol ORF2 of this mobile genetic element was demonstrated to code for an active Reverse Transcriptase (RT) and the ORF1 is expected to code for the structural Gag proteins of the virus‐like particles (VLP). Using specific anti‐Gag antibodies, we have characterized the 1731 Gag polypeptides expressed either in vitro or in Kc Drosophila melanogaster cultured cells. Together with the 1731 RT, the largest, likely post‐translationaly‐modified Gag polypeptides are gathered into cytoplasmic virus‐like particles. Moreover and consistent with the nuclear localization signal present in the Gag sequence, we observed that a short 1731 Gag polypeptide is associated to the cell nuclei.
Phosphatase inhibition in human neuroblastoma cells alters tau antigenicity and renders it incompetent to associate with exogenous microtubules
Authors: Shea Thomas B. , Fischer Itzhak
Published: April 2003

The abnormal cytoskeletal organization observed in Alzheimer's disease has been suggested to arise from hyperphosphorylation of tau and the resultant elimination of its ability to associate with microtubules. This possibility has been supported by a number of studies under cell‐free conditions utilizing various kinases, phosphatases and their corresponding inhibitors each, and by treatment of intact cells with kinase and phosphatase activators and inhibitors. However, in studies utilizing intact cells, it remained difficult to attribute microtubule compromise specifically to tau hyperphosphorylation due to potential influence of inhibitors on tubulin and/or other microtubule‐associated proteins, which themselves possess assembly‐regulatory phosphorylation sites. To address this difficulty, we subjected SH‐SY 5Y human neuroblastoma cells to treatment with the phosphatase inhibitor okadaic acid (OA), which has been previously demonstrated to depolymerize microtubules in these cells. OA induced an increase in tau hyperphosphorylation as evidenced by an increase in Alz‐50 immunoreactivity and a corresponding decrease in Tau‐1 immunoreactivity. When tau‐enriched fractions from OA‐treated cells were incubated under microtubule assembly‐promoting conditions with twice‐cycled, tau‐free preparations of bovine brain tubulin not exposed to OA, Alz‐50‐immunoreactive tau isoforms displayed a marked (49%) reduction in ability to co‐assemble with bovine microtubules as compared with Tau‐1‐and 5E2‐immunoreactive isoforms. These data indicate that hyperphosphorylated tau has a reduced capacity to associate with microtubules, and support the hypothesis that tau hyperphosphorylation may underlie microtubule breakdown in Alzheimer's disease.
Mechanisms of opsonized HIV entry in normal B lymphocytes
Authors: Legendre Christophe , Gras Gabriel , Krzysiek Roman , Galanaud Pierre , Richard Yolande , Dormont Dominique
Published: April 2003

Using our in vitro model of normal B cell infection that functions with low doses of HIV but requires virus opsonization by seropositive patient serum, and complement, we analyzed what receptors allowed virus entry. Here, we show that HIV infection of B cells occurs through 2 major receptors: the CD4 antigen and the CR1/CR2 complex. These 2 pathways work independently since a complete inhibition of virus entry requires both CD4 and CD21/CD35 blockade on CD4dim tonsillar B cells whereas only the latter is critical on CD4‐negative B cells.
Expression of c‐fos gene inhibits proteoglycan synthesis in transfected chondrocyte
Authors: Tsuji Michiko , Funahashi Shin-ichi , Takigawa Masaharu , Seiki Motoharu , Fujii Katsuyuki , Yoshida Takeshi
Published: April 2003

The effect of expression of c‐fos gene on proteoglycan synthesis, one of the important markers of cartilage metabolism, was examined by introducing the c‐fos DNA into HCS 2/8 chondrocytes. The [35S]sulfate incorporation into proteoglycan was decreased in the c‐fos transfectants expressing exogenous c‐fos mRNA, when compared to a control transfectant. A significant increase in transcription of MMP‐3 with the suppressed transcription of aggrecan and TIMP‐1 were also observed in the c‐fos transfectants. Moreover, analysis of the effect of AP‐1 proteins on the collagenase and TIMP‐1 promoters in gastric carcinoma KKLS cells revealed that c‐Fos combined with any of the Jun‐related proteins failed to stimulate the TIMP‐1 promoter, though collagenase promoter was effectively activated by any Fos/Jun‐related protein heterocomplex. These findings indicate that the c‐fos expression may govern the cartilage metabolism and hence may play an important role in the pathogenesis of joint destruction in arthritis.
Metabolism of angiotensins by head membranes of the leech Theromyzon tessulatum
Authors: Laurent Virginie , Salzet Michel
Published: April 2003

Angiotensins (angiotensin I, angiotensin II, angiotensin II‐amide) have been isolated in leeches and such peptides are involved in diuresis in these animals. To explore possible inactivation mechanisms of these peptides, angiotensins were incubated with head membranes of the leech T. tessulatum. Membranes derived from head parts of this leech are very rich in peptidases. They contain endopeptidase‐24.11‐like enzyme (NEP‐like) associated with a battery of exopeptidase. The way that angiotensins are degraded by the combined attack of these membrane peptidases has been investigated. The contribution of individual peptidases was assessed by adding inhibitors (phosphoramidon, captopril and amastatin) to the membrane fractions, when they were incubated with the peptides. In the case of angiotensin I, the primary attack was performed by a combined action of the NEP‐like and the ACE‐like enzymes, followed by aminopeptidase attacks. Angiotensin II and III were hydrolyzed by NEP‐like enzyme at the same Tyr‐Ile bond, whereas the N‐terminal arginine residue of angiotensin III was removed by an arginyl aminopeptidase. These results show that angiotensins are efficiently degraded by membranes and that NEP‐like enzyme plays a key role in this process.
Inhibition of creatine kinase by S‐nitrosoglutathione
Authors: Wolosker Herman , Panizzutti Rogério , Engelender Simone
Published: April 2003

The sarcoplasmic reticulum‐bound creatine kinase from rabbit skeletal muscle was inhibited by the nitric oxide donor S‐nitrosoglutathione (GSNO). This led to a decrease in Ca2+ uptake in sarcoplasmic reticulum vesicles when the transport was driven by ATP generated from phosphocreatine and ADP. In contrast, the Ca2+ transport measured using 2 mM ATP as substrate was unaffected by GSNO up to 200 μM. GSNO (5–20 μM) inhibited the activity of both soluble and membrane‐bound creatine kinase. Oxyhemoglobin (15–40 μM) protected creatine kinase against inactivation by GSNO. The inhibition by 10 μM GSNO was reversed by the addition of dithiothreitol (2 mM). The results indicate that nitric oxide (NO, including NO+, NO and NO−) inactivates creatine kinase in vitro by promoting nitrosylation of critical sulphydryl groups of the enzyme.
Loop mutations affect ferritin solubility causing non‐native aggregation of subunits or precipitation of fully assembled polymers
Authors: Jappelli Roberto , Cesareni Gianni
Published: April 2003

As a consequence of elevated expression rates, the intracellular aggregation of polypeptide chains is commonly observed in E. coli. Although wild‐type human ferritin, a polymeric iron storage protein, accumulates in the soluble form at high level in the bacterial cytoplasmic fraction, some amino acid substitutions in an exposed loop direct the synthesis of a highly insoluble product. We found that two mechanisms can lead to the aggregation of ferritin. While some mutations prevent ferritin polymerisation, others cause the precipitation of molecules in the assembled state.
1H NMR studies of the paramagnetic CuA center of cytochrome oxidase
Authors: Dennison Christopher , Berg Axel , de Vries Simon , Canters Gerard W.
Published: April 2003

The dinuclear paramagnetic center of the soluble Cu
A
domain of the cytochrome c oxidase from Bacillus subtilis has been studied using 1H NMR. The spectrum possesses remarkably sharp shifted resonances. Comparison with the spectrum of the Cu
A
amicyanin variant provides the spin density distribution in the Cu
A
site of cytochrome c oxidase. This represents the first paramagnetic NMR study of the dinuclear Cu
A
center from the soluble domain of subunit II of cytochrome c oxidase.
Kinetics of binding of Antp homeodomain to DNA analyzed by measurements of surface plasmon resonance
Authors: Seimiya Makiko , Kurosawa Yoshikazu
Published: April 2003

The kinetics of binding of the Antp homeodomain to three kinds of DNA fragment were analyzed by measurements of surface plasmon resonance at various temperatures. Non‐specific and specific binding of the homeodomain to DNA was examined. In the case of non‐specific binding, the association rate constant (k
ass) was estimated to be 1.41–2.62 × 105 M−1 s−1 and the dissociation rate constant (k
diss) was 1.36–3.10 × 10−2 s−1, thus, the dissociation constant (K
D) was 0.847–1.72 × 10−7 M. The association seemed to be driven by entropy. In the case of specific binding, by contrast, the enthalpy term seemed to contribute more to the binding than did the entropy term. The k
ass was 2.04–2.59 × 105 M−1 s−1 and the k
diss was 0.759–1.16 × 10−3 s−1, thus, the K
D was 2.93–5.69 × 10−9 M. These values were measured under the condition of 150 mM NaCl. Both interactions were strongly dependent on the concentration of NaCl. The K
D at 50 mM NaCl became several tens of times smaller than those at 150 mM. Possible reasons for the differences between non‐specific and specific interactions are discussed.
Profilin is required for the normal timing of actin polymerization in response to thermal stress
Authors: Yeh Juddi , Haarer Brian K.
Published: April 2003

We have used a fluorometric assay to determine the relative amounts of polymerized actin (F‐actin) in wild‐type and profilin mutant yeast cells. Our results indicate that profilin plays a role in maintaining normal F‐actin levels in response to shifts to high temperature. Cells lacking profilin display a greater drop in F‐actin levels upon such temperature shifts, and are slower to recover to initial F‐actin levels than are wild‐type cells. Interestingly, shifts to cold temperatures result in rapid increases of F‐actin levels in wild‐type and profilin null cells. We have further determined that shifting to high‐osmolarity growth conditions causes a relatively slow decrease in F‐actin levels in wild‐type cells, and a small but rapid increase in the F‐actin levels in profilin null cells. Profilin null cells contain normal concentrations of F‐actin while growing exponentially at room temperature, indicating that profilin is not essential for maintaining F‐actin concentrations during steady‐state growth. Our data suggest that actin is inherently unstable in vivo at high temperatures, and that profilin helps to maintain actin in its filamentous state at these temperatures, perhaps by stimulating actin polymerization in a proper temporal and spatial fashion.
Arrest of mitochondrial biogenesis in copper‐treated sycamore cells
Authors: Pádula Mário , Aubert Serge , Casimiro Adalcina , Bligny Richard
Published: April 2003

Sycamore suspension cells (Acer pseudoplatanus L.) were grown in the presence of sublethal concentrations of copper (50 μM). During the first 5–6 days of treatment, growth was not affected, but cell respiration (coupled and uncoupled) declined to ∼60% of its normal value. This decline of respiration was attributed to a progressive diminution of the number of mitochondria in copper‐treated cells, based on the demonstration of the concomitant decline of (1) cardiolipin (diphosphatidylglycerol) and cytochrome aa
3 (cytochrome oxidase), two specific markers of mitochondrial inner membrane, and (2) fumarase activity, a specific marker of mitochondrial matrix space. In addition, the mitochondria extracted from copper‐treated cells presented the same properties as those from control cells, concerning substrate oxidation, cardiolipin and cytochrome aa
3 contents, and fumarase activity. These results strongly suggest that copper triggered an arrest of mitochondrial biogenesis, which preceded cell division arrest.
Use of the female condom among sex workers in China
Authors: Yimin C , Zhaohui L , Xianmi W , Shiying W , Lingzhi H , Yueying X , Xiaolan H , Lifen X , Yunzhen W , Shaolan Z , Yulian L
Published: April 2003

Objectives: To introduce the female condom (FC) among sex workers (SWs) in China. Methods: We adopted the intervention study method. The 315 participating SWs were randomly assigned to an intervention group (155 SWs) or a control group (160 SWs). Results: The rate of SWs who reported liking FC increased from 60.0% pre‐intervention to 93.5% post‐intervention, and the rate of SWs who considered that their clients could accept FC increased from 27.1% to 92.3%. After the intervention, 93.5% expressed that their sexual satisfaction had increased with their familiarity with FC and 97.4% expressed that they would use it in the future. Conclusions: The understanding and use of FC can be greatly improved through active intervention—i.e. medical workers providing SWs with FC.
Quality development in perinatal care — the OBSQID project
Authors: Johansen K.S , Hod M
Published: April 2003

This special communication describes the objectives and strategies of the OBStetrical Quality Indicators and Data collection (OBSQID) project, a pan‐European network of researchers, healthcare providers, and professional institutions and associations using agreed key quality indicators and served by a common database. OBSQID is based on the general concept of continuous assessment, management and development of quality of care and is geared to perinatal medicine. It allows contributors to measure, on an on‐going basis, the outcomes of care they provide against those of other facilities within their own region or country as well as in Europe. It identifies ‘best practices’ and allows for the exchange and transfer of knowledge and expertise through ‘twinning’ or collaborative partnerships [1]. It also assists in setting general quality standards as well as specific guidelines aimed at ensuring all patients high quality, cost‐effective care.
Substance and Process in the Development of Party Systems in East Central Europe
Authors: Bielasiak Jack
Published: April 2003

What conditions in post-communism affect the rise of competitive political parties capable of providing significant options to the electorate? The initial wisdom held that numerous weaknesses of political society in East Central Europe impeded the consolidation of a stable party system. More recently, two distinct schools emerged to present a more structured view of political space. One relies on a substantive evaluation of political cleavages, ideological posturing, and issue relevance to map party positions and voter placements in post-communist politics. This approach concentrates on emerging social and economic cleavages as the foundation of party systems. The second approach focuses on a process perspective that looks to political mechanisms such as elections and coalition formation that act as a funnel for the formation of new party systems. This article combines the substantive and process understandings of political choice to provide a comprehensive analysis of the transformation of party systems in post-communist states. The concentration is both on the demand side of the electoral process, i.e. the formation of cleavages among the electorate, and on the supply side, i.e. the channeling of political options through institutional mechanisms. Together, the process of party evolution and the substance of party differentiation help to define the hegemonic, polarized, fragmented, and pluralist phases in the consolidation of party systems in post-communism.
FINITE VEV'S FROM A LARGE DISTANCE VACUUM WAVE FUNCTIONAL
Authors: JARAMILLO ALFONSO , MANSFIELD PAUL
Published: April 2003

We show how to compute vacuum expectation values from derivative expansions of the vacuum wave functional. Such expansions appear to be valid only for slowly varying fields, but by exploiting analyticity in a complex scale parameter we can reconstruct the contribution from rapidly varying fields.
THE RELATION BETWEEN CHIRAL SYMMETRY SPONTANEOUSLY BREAKING AND CONFINEMENT IN QED
Authors: SU-PENG KOU
Published: April 2003

In this paper, we use Parisi and Sourlas dimensional reduction to show that QED has two phases, the strong coupling phase and weak coupling phase. Because chiral symmetry is spontaneously broken, particles with fractional charges are confined in the strong coupling phase by the condensation of topological configurations, and particles with integer charges are screened by fermion pairs.
SEARCH FOR THE STANDARD MODEL HIGGS BOSON WITH THE ALEPH DETERCTOR AT LEP2
Authors: NIELSEN JASON
Published: April 2003

As the LEP collider at CERN has increased its maximum center-of-mass energy to 209 GeV, a total integrated luminosity of 99.8 pb -1 has been collected in the ALEPH detector. The ALEPH searches for Higgs bosons have been updated, But no firm evidence for Higgs production has been observed. Standard Model Higgs boson production is excluded at 95% confidence level for Higgs masses less than 111.1 GeV/c 2, and the combined LEP results exclude Higgs masses below 113.3 GeV/c 2. The recently-granted LEP extension will allow the a currently 2σ fluctuation from background expectation at m H = 115 GeV/c 2 to become more significant if it is truly due to Higgs production.
ASSOCIATED TOP-HIGGS PRODUCTION AT FUTURE COLLIDERS
Authors: Dawson Sally , Reina Laura
Published: April 2003

We discuss the relevance of the associated production of a Higgs boson with a pair of top antitop quarks at both the LHC and a future high energy e+e- collider.
CDF Run II Prospects for Bs Mixing
Authors: Martin Matthew S.
Published: April 2003

We give a prediction of the Bs mixing reach (xs) for the first two years of CDF Run II. We mention the important samples, and their expected yields. If the experiment performs to our expectations, we expect either to measure Bs mixing, or to comprehensively rule out the Standard Model predictions.
τ→ω3πν Decays
Authors: Gao Jun , Li Bing An
Published: April 2003

Theoretical study of τ→ωπππν is presented. Theoretical value of the branching ratio of τ-→ ωπ-π0π0 ν agrees well with data. The branching ratio of τ-→ωπ+π-π-ντ is predicted. The vertices of a1ρπ and ωρπ play dominant role in these two decay modes. CVC is satisfied and there is no adjustable parameter.
TAU DECAYS WITH CHARGED KAONS AT OPAL
Authors: TOWERS S.
Published: April 2003

From an analysis of the ionisation energy loss of charged particles selected from tau pair candidates recorded in the OPAL detector at centre-of-mass energies near the Z0 resonance, we determine competitive measurements of the τ-→ντ K -≥ 0h 0 branching ratio, where the h0 notation refers to a π0, an η, a [Formula: see text], or a [Formula: see text]. We also determine the τ-→ντ K -π- π+(π0) and τ-→ντ K -π- K +(π0) branching fractions, where the (π0) notation refers to decay modes with or without an accompanying π0. In addition, we examine the resonant structure of τ-→ντ K -π-π+ candidates, and find that the resonant structure is dominated by the K1(1270) resonance.
DETECTION OF VERY SMALL NEUTRINO MASSES IN DOUBLE-BETA DECAY USING LASER TAGGING
Authors: WALDMAN S.
Published: April 2003

We describe an approach to the study of neutrino masses that combines quantum optics techniques with radiation detectors to obtain unprecedented sensitivity. With our approach, the search for Majorana neutrino masses down to ~10 meV will become feasible. The experimental technique uses the detection of individual Ba+-ions in the final states of 136 Xe double-beta decay via optical excitation to suppress radioactive backgrounds.
The Status of MiniBooNE
Authors: HAWKER ERIC A.
Published: April 2003

MiniBooNE is a neutrino oscillation experiment that will provide an important check of the evidence for νμ→νe oscillations reported by the LSND experiment. The current status of the design and construction efforts for MiniBooNE will be reported.
The Degenerate Wino-like Chargino-Neutralino Scenario at Hadron Colliders
Authors: Mrenna Stephen , Gunion John F.
Published: April 2003

For some choices of soft SUSY-breaking parameters, the LSP is a stable neutralino [Formula: see text], the NLSP is a chargino [Formula: see text] almost degenerate in mass with the LSP [Formula: see text], and all other sparticles are relatively heavy. We discuss the potential of hadron colliders, particularly the LHC, for studying such models.
DISCOVERY AND IDENTIFICATION OF W′ BOSONS AT e+e- COLLIDERS
Authors: GODFREY STEPHEN , KALYNIAK PAT , KAMAL BASIM , DONCHESKI M. A. , LEIKE ARND
Published: April 2003

We report on studies of the sensitivity to extra gauge bosons of the reactions [Formula: see text] and eγ→νq+X to extract discovery limits for W′'s. The discovery potential for a W′ is, for some models, comparable to that of the LHC. These processes may be also useful for determining W′ and Z′ couplings to fermions which would complement measurements made at the Large Hadron Collider.
A NEW SEARCH FOR LEPTON FLAVOR VIOLATION IN HIGH-Q2 POSITRON-PROTON COLLISIONS
Authors: EPPERSON DOUGLAS
Published: April 2003

A search for Lepton Flavor Violation in Deeply Inelastic positron-proton scattering was conducted at the HERA Colider, using the ZEUS detector. This process permits the probing of the four-fermion interaction, in particular those terms that involve two quarks and two leptons. Strong limits exist from rare decays and from lower-energy experiments, but they involve the lighter quarks. At HERA, limits can be set that also involve interactions with heavier sea quarks, and all three lepton families. these limits define the energy scale probed in the effective Lagrangian, and, in a more specific model, involving leptoquarks. While no events survived the selection criteria, two interesting candidate events are discussed.
INVESTIGATION OF A TOY MODEL FOR FRUSTRATION IN ABELIAN LATTICE GAUGE THEORY
Authors: AZCOITI V. , FOLLANA E. , DI CARLO G.
Published: April 2003

We introduce a lattice model with local U(1) gauge symmetry which incorporates explicit frustration in d>2. The form of the action is inspired from the loop expansion of the fermionic determinant in standard lattice QED. We study through numerical simulations the phase diagram of the model, revealing the existence of a frustrated (antiferromagnetic) phase for d=3 and d=4, once an appropriate order parameter is identified.
MAPPING CLASS GROUP REPRESENTATIONS AND GENERALIZED VERLINDE FORMULA
Authors: BÁNTAY PETER , VECSERNYÉS PETER
Published: April 2003

Unitary representations of centrally extended mapping class groups [Formula: see text], g ≥ 1 are given in terms of a rational Hopf algebra H, and a related generalization of the Verlinde formula is presented. Formulae expressing the traces of mapping class group elements in terms of the fusion rules, quantum dimensions and statics phases are proposed.
BOUNDS ON THE LIGHTEST HIGGS BOSON MASS WITH THREE AND FOUR FERMION GENERATIONS
Authors: DOOLING DAVID , KANG KYUNGSIK , KANG SIN KYU
Published: April 2003

We present lower bounds on the Higgs boson mass in the Standard Model with three and four fermion generations, SM (3,4), as well as upper bounds on the lightest Higgs boson mass in the minimal supersymmetric extension of the SM with three and four generations, MSSM (3,4). Our analysis utilizes the SM (3,4) renormalization-group-improved one-loop effective potential of the Higgs boson to find the upper bounds on the Higgs mass in the MSSM (3,4), while the lower bounds in the SM (3,4) are derived from considerations of vacuum stability. All the bounds increase as the degenerate fourth generation mass increases, providing more room in theory space that respects the increasing experimental lower limit of the Higgs mass.
TOWARD CLASSIFICATION OF THE REALISTIC FREE-FERMIONIC SUPERSTRING MODELS
Authors: FARAGGI ALON E.
Published: April 2003

The realistic free-fermionic models have had remarkable success in providing plausible explanations for various properties of the Standard Model, which include the natural appearance of three generations, the explanation of the heavy top quark mass and the qualitative structure of the fermion mass spectrum in general, the stability of the proton, and more. These intriguing achievements make evident the need to understand the general space of these models. While the number of possibilities is large, general patterns can be extracted. In this paper I present a detailed discussion on the construction of the realistic free-fermionic models with the aim of providing some insight into the basic structures and building blocks that enter the construction. The role of free phases in the determination of the phenomenology of the models is discussed in detail. I discuss the connection between the free phases and mirror symmetry in (2,2) models and the corresponding symmetries in the case of (2,0) models. The importance of the free phases in determining the effective low energy phenomenology is illustrated in several examples. The classification of the models in terms of boundary condition selection rules, real world-sheet fermion pairings, exotic matter states and the hidden sector is discussed.
STOP SQUARK SEARCH AT TEVATRON IN THE LIGHT SLEPTON SCENARIO
Authors: DATTA ASESHKRISHNA , GUCHAIT MONORANJAN , JEONG KYOUNG KEUN
Published: April 2003

In minimal-supergravity-based supersymmetry models the charged sleptons as well as the sneutrinos may be lighter than the squarks. In such a light slepton scenario search for the lighter stop squark has been investigated in the dilepton + missing pT[Formula: see text](≥ 1) channel at Tevatron. In this scenario semileptonic decay of the lighter stop squark has been considered via off-shell and on-shell charginos. In the latter case the chargino undergoes pure leptonic two-body decay. We observe that for some favorable region of the MSSM parameter space one can probe the lighter stop squark mass up to 140 GeV with few events in the present data set for which the luminosity is 110 pb -1. At the MI upgrade one is likely to end up with more events.
THE STRING TENSION IN TWO-DIMENSIONAL GAUGE THEORIES
Authors: ARMONI A. , SONNENSCHEIN J. , FRISHMAN Y.
Published: April 2003

We review and elaborate on properties of the string tension in two-dimensional gauge theories.

The first model we consider is massive QED in the m≪e limit. We evaluate the leading string tension both in the fermionic and bosonized descriptions. We discuss the next-to-leading corrections in m/e. The next-to-leading terms in the long distance behavior of the quark–antiquark potential, are evaluated in a certain region of external versus dynamical charges. The finite temperature behavior is also determined.

In QCD 2 we review the results for the string tension of quarks in cases with dynamical quarks in the fundamental, adjoint, symmetric and antisymmetric representations. The screening nature of SYM 2 is re-derived.
DIRAC VARIABLES AND ZERO MODES OF GAUSS CONSTRAINT IN FINITE-VOLUME TWO-DIMENSIONAL QED
Authors: GOGILIDZE S. , ILIEVA NEVENA , PERVUSHIN V. N.
Published: April 2003

The finite-volume QED 1+1 is formulated in terms of Dirac variables by an explicit solution of the Gauss constraint with possible nontrivial boundary conditions taken into account. The intrinsic nontrivial topology of the gauge group is thus revealed together with its zero-mode residual dynamics. Topologically nontrivial gauge transformations generate collective excitations of the gauge field above Coleman's ground state, that are completely decoupled from local dynamics, the latter being equivalent to a free massive scalar field theory.
FROM p-BRANES TO COSMOLOGY
Authors: LÜ H. , MUKHERJI S. , POPE C. N.
Published: April 2003

We study the relationship between static p-brane solitons and cosmological solutions of string theory or M theory. We discuss two different ways in which extremal p-branes can be generalized to nonextremal ones, and show how wide classes of recently discussed cosmological models can be mapped into nonextremal p-brane solutions of one of these two kinds. We also extend previous discussions of cosmological solutions to include some that make use of cosmological-type terms in the effective action that can arise from the generalized dimensional reduction of string theory or M theory.
GAUSSIAN EFFECTIVE POTENTIAL ANALYSIS OF SINH(SINE)–GORDON MODELS NEW REGULARIZATION–RENORMALIZATION SCHEME
Authors: FENG SZE-SHIANG , NI GUANG-JIONG
Published: April 2003

Using the new regularization and renormalization scheme recently proposed by Yang and used by Ni et al., we analyze the sine–Gordon and sinh–Gordon models within the framework of Gaussian effective potential in D+1 dimensions. Our analysis suffers no divergence and so does not suffer from the manipulational obscurities in the conventional analysis of divergent integrals. Our main conclusions agree exactly with those of Ingermanson for D=1,2 but disagree for D=3: the D=3 sinh(sine)–Gordon model is nontrivial. Furthermore, our analysis shows that for D=1,2, the running coupling constant (RCC) has poles for sine–Gordon model (γ2<0) and the sinh–Gordon model (γ2>0) has a possible critical point [Formula: see text] while for D=3, the RCC has poles for both γ2>0 and γ2<0.
THE MASS OF A QUARK–SQUARK BOUND STATE FROM QCD SUM RULES
Authors: MEYER-HERMANN M. , SCHÄFER A.
Published: April 2003

We give an estimate of the expected mass range for a possible two-quark two-squark bound state, using QCD sum rules. The sum rules are modified, taking mass effects into account, so that a treatment of heavy squarks becomes justified. The influence of the higher-order mass corrections and the possibility of a bound state mass below the squark mass are discussed.
INTEGRABLE SYSTEMS IN ONE AND TWO DIMENSIONS AND REDUCED TOPOLOGICAL GAUGE THEORIES
Authors: LEGARÉ M.
Published: April 2003

A set of integrable systems are shown to be related to BRST-invariant systems derived from topological Yang–Mills theories under reductions, with often additional algebraic conditions. Supersymmetric quantum mechanical formulations of one-dimensional integrable cases are also compared and discussed.
CHAOTIC BEHAVIOR IN A Z2 × Z2 FIELD THEORY
Authors: LATORA V. , BAZEIA D.
Published: April 2003

We investigate the presence of chaos in a system of two real scalar fields with discrete Z2×Z2 symmetry. The potential that identifies the system is defined with a real parameter r and presents distinct features for r>0 and for r<0. For static field configurations, the system supports two topological sectors for r>0, and only one for r<0. Under the assumption of spatially homogeneous fields, the system exhibits chaotic behavior almost everywhere in parameter space. In particular a more complex dynamics appears for r>0; in this case chaos can decrease for increasing energy, a fact that is absent for r<0.
PARALLEL MATCHING OF 3D ARTICULATED OBJECT RECOGNITION
Authors: WANG PATRICK S. P.
Published: April 2003

In dealing with large volume image data, sequential methods usually are too slow and unsatisfactory. This paper introduces a new system employing parallel matching in high-level recognition of 3D articulated objects. A new structural strategy using linear combination and parallel graphic matching techniques is presented for 3D polyhedral objects representable by 2D line-drawings. It solves one of the basic concerns in diffusion tomography complexities, i.e. patterns can be reconstructed through fewer projections, and 3D objects can be recognized by a few learning sample views. It also improves some of the current methods while overcoming their drawbacks. Furthermore, it can distinguish very similar objects and is more accurate than other methods in the literature. An online webpage system for understanding and recognizing 3D objects is also illustrated.
AN INCREMENTAL LEARNING NEURAL NETWORK FOR PATTERN CLASSIFICATION
Authors: HUNG CHENG-AN , LIN SHENG-FUU
Published: April 2003

A neural network architecture that incorporates a supervised mechanism into a fuzzy adaptive Hamming net (FAHN) is presented. The FAHN constructs hyper-rectangles that represent template weights in an unsupervised learning paradigm. Learning in the FAHN consists of creating and adjusting hyper-rectangles in feature space. By aggregating multiple hyper-rectangles into a single class, we can build a classifier, to be henceforth termed as a supervised fuzzy adaptive Hamming net (SFAHN), that discriminates between nonconvex and even discontinuous classes. The SFAHN can operate at a fast-learning rate in online (incremental) or offline (batch) applications, without becoming unstable. The performance of the SFAHN is tested on the Fisher iris data and on an online character recognition problem.
ON PRE-PLAY NEGOTIATIONS AND ZERO-SUM BETTING
Authors: PERETS HOVAV , SONSINO DORON
Published: April 2003

Sebenius and Geanakoplos (1983) have proven the "impossibility of zero-sum betting" in a simple non-strategic model. We study a dynamic game of incomplete information that extends the Sebenius and Geanakoplos framework, and show that the no-betting result carries over to the extended game.
AN OVERVIEW OF PHOTO-REALISM FOR OUTDOOR SCENES
Authors: NAKAMAE EIHACHIRO
Published: April 2003

This paper examines rendering techniques of outdoor scenes intended for use in visual environmental assessment using computer graphics and/or video sequence images and discusses their advantages and limitations. The techniques are classified into the following three categories. First, rendering techniques of computer generated images and montages creating a photo-realistic landscape image based on optical phenomena are introduced; these are quite useful for careful and detailed study of landscapes. Second, a method for creating a precise panoramic image from panned video sequence images taken on a tripod is introduced; this is very useful for evaluating the whole visual landscape. Third, technique examined is panned/zoomed landscape video sequence images well matched with photo realistic computer generated still images such as bridges and electric power transmission towers; this provides an especially vivid and lifelike impression.
ON THE COMPRESSION OF IMAGE BASED RENDERING SCENE: A COMPARISON AMONG BLOCK, REFERENCE AND WAVELET CODERS
Authors: LI JIN , SHUM HEUNG-YEUNG , ZHANG YA-QIN
Published: April 2003

In image based rendering (IBR), a 3D scene is recorded through a set of photos which is then rendered to form novel views. Compression is essential to reduce the huge data amount of IBR. In this paper, we examine three categories of IBR compression algorithms: the block coder, the reference coder and the wavelet coder. We examine both the compression efficiency and the capability to render the compressed IBR bitstream in real-time. It is observed that the block coder consumes the least computation resource, however, its compression ratio is low. The reference coder achieves good compression ratio with reasonable computation complexity. The wavelet coder achieves the best compression ratio.
The non‐steroidal anti‐inflammatory drug, indomethacin, as an inhibitor of HIV replication
Authors: Bourinbaiar Aldar S. , Lee-Huang Sylvia
Published: April 2003

Indomethacin, a common non‐steroidal anti‐inflammatory drug (NSAID), has been used to treat rheumatoid arthritis. Although indomethacin has also been used as an immunopotentiator and symptomatic NSAID in AIDS, its effect on HIV replication is unknown. MT‐4 lymphocytes were inoculated with HIV in the presence of indomethacin and tested for p24 expression by ELISA. The 50% inhibition (IC50) was 10 μM, corresponding to plasma levels after administration of 50 mg oral indomethacin. The antiviral effect appears to be specific since no toxicity has been observed at the IC50 dose, and unrelated NSAIDs have not shown the activity at clinical doses. Indomethacin may, thus, represent a new class of anti‐HIV drug.
The use of electrospray mass spectrometry to identify an essential arginine residue in type II dehydroquinases
Authors: Krell Tino , Pitt Andrew R. , Coggins John R.
Published: April 2003

The arginine‐specific reagent phenylglyoxal has been used to identify a hyper‐reactive arginine residue which is essential for activity in the type II dehydroquinases of Streptomyces coelicolor and Aspergillus nidulans. Electrospray mass spectrometry was used both to characterise the phenylglyoxal modified protein, and to identify the phenylglyoxal modified peptides following enzymatic digestion. The advantages of using electrospray mass spectrometry for monitoring arginine modication aimed at identifying functional residues in proteins are discussed.
Ribosomal frameshifting at the Gag‐Pol junction in avian leukemia sarcoma virus forms a novel cleavage site
Authors: Arad G. , Bar-Meir R. , Kotler Moshe
Published: April 2003

The Gag and Gag‐Pol precursors of avian sarcoma leukemia virus (ASLV) are translated from viral genomic‐size mRNA at a molar ratio of about 20:1. Translation of Gag is terminated at the stop codon UAG located at the carboxyl‐terminus of the viral protease (PR), whereas a ribosomal frameshift occurring at the carboxyl‐terminus of Gag allows translation of the Gag‐Pol precursor. To determine how PR is released from the Gag‐Pol precursor, a single base (A or T) was inserted at the Gag‐Pol junction in order to adjust the translation into a single reading frame. These mutations allow processing of the viral precursor when expressed in bacterial cells, but cause cessation of viral production after transfection of avian cells. The viral PR released from the large precursor is one amino acid longer than PR cleaved from the Gag polyprotein and is terminated by an Ile instead of a Leu residue.