bluuebunny/crossref_metadata_2025 huggingface dataset:
INFRARED BEHAVIOR OF SYSTEMS WITH GOLDSTONE BOSONS
Authors: ANISHETTY RAMESH , BASU RAHUL , DASS N. D. HARI , SHARATCHANDRA H. S.
Published: April 2003

We develop various complementary concepts and techniques for handling quantum fluctuations of Goldstone bosons. We emphasize that one of the consequences of the masslessness of Goldstone bosons is that the longitudinal fluctuations also have a diverging susceptibility characterized by an anomalous dimension (d-2) in space–time dimensions 2<d<4. In d=4 these fluctuations diverge logarithmically in the infrared region. We show the generality of this phenomenon on the basis of (i) Renormalization group flows, (ii) Ward identities, and (iii) Schwinger–Dyson equations. We also obtain an explicit form for the generating functional of one-particle irreducible vertices of the O(N) (non)linear σ models in the leading 1/N approximation. We show that this incorporates all infrared behavior correctly both in linear and nonlinear σ models. Some consequences are discussed briefly.
QUANTUM PROPERTIES OF GENERAL GAUGE THEORIES WITH COMPOSITE AND EXTERNAL FIELDS
Authors: FALKENBERG S. , GEYER B. , MOSHIN P.
Published: April 2003

The generating functionals of Green functions with composite and external fields are considered in the framework of BV and BLT quantization methods for general gauge theories. The corresponding Ward identities are derived and the gauge dependence is investigated.
NONSTANDARD MATRIX FORMATS OF LIE SUPERALGEBRAS
Authors: DELDUC F. , GIERES F. , GOURMELEN S. , THEISEN S.
Published: April 2003

The standard format of matrices belonging to Lie superalgebras consists of partitioning the matrices into even and odd blocks. In this paper, we present a systematic study of other possible matrix formats and in particular of the so-called diagonal format which naturally occurs in various physical applications, e.g. for the supersymmetric versions of conformal field theory, integrable models. W algebras and quantum groups.
THE ABELIAN HIGGS MODEL AS AN ENSEMBLE OF VORTEX LOOPS
Authors: ANTONOV DMITRI
Published: April 2003

In the London limit of the Ginzburg–Landau theory (Abelian Higgs model), vortex dipoles (small vortex loops) are treated as a grand canonical ensemble in the dilute gas approximation. The summation over these objects with the most general rotation and translation-invariant measure of integration over their shapes leads to effective sine–Gordon theories of the dual fields. The representations of the partition functions of both grand canonical ensembles are derived in the form of the integrals over the vortex dipoles and the small vortex loops, respectively. By virtue of these representations, the bilocal correlator of the vortex dipoles (loops) is calculated in the low-energy limit.

It is further demonstrated that once the vortex dipoles (loops) are considered as such an ensemble rather than individual ones, the London limit of the Ginzburg–Landau theory (Abelian Higgs model) with external monopoles is equivalent up to the leading order in the inverse UV cutoff to the compact QED in the corresponding dimension with the charge of Cooper pairs changed due to the Debye screening.
QUANTUM GEOMETRODYNAMICS OF THE BIANCHI-IX MODEL IN EXTENDED PHASE SPACE
Authors: SAVCHENKO V. A. , SHESTAKOVA T. P. , VERESHKOV G. M.
Published: April 2003

A way of constructing mathematically correct quantum geometrodynamics of a closed universe is presented. The resulting theory appears to be gauge-noninvariant and thus consistent with the observation conditions of a closed universe, by that being considerably distinguished from the traditional Wheeler–DeWitt one. For the Bianchi-IX cosmological model it is shown that a normalizable wave function of the universe depends on time, allows the standard probability interpretation and satisfies a gauge-noninvariant dynamical Schrödinger equation. The Wheeler–DeWitt quantum geometrodynamics is represented a singular, BRST-invariant solution to the Schrödinger equation having no property of normalizability.
THEORETICAL UNCERTAINTIES IN Γsl (b → u)
Authors: URALTSEV NIKOLAI
Published: April 2003

I review the existing theoretical uncertainties in relating the semileptonic decay width in b → u transitions to the underlying Kobayashi–Maskawa mixing element |Vub|. The theoretical error bars are only a few per cent in |Vub|, with uncertainties from the impact of the nonperturbative effects nearly negligible.
GRAVITATIONAL AND MATTER ENERGY–MOMENTUM DENSITIES AND EQUIVALENCE PRINCIPLE IN NON-RIEMANNIAN GEOMETRIES
Authors: CASTAGNINO M. , LEVINAS M. L. , UMÉREZ N.
Published: April 2003

We introduce an energy–momentum density vector which is independent of the affine structure of the manifold. Conservation of this quantity is linked to observers. Integrating over timelike surfaces, we define the Hamiltonian and momentum of the system which coincide with the corresponding standard ADM definitions when taking adequate asymptotical conditions. We define an Equivalence Principle for manifolds with torsion as a possible extension of the Equivalence Principle of General Relativity to non-Riemannian geometries.
STUDY OF TWO-BODY HADRONIC DECAYS OF Λb BARYON IN THE HEAVY QUARK EFFECTIVE THEORY
Authors: MOHANTA RUKMANI
Published: April 2003

We investigate the two-body nonleptonic weak decays of Λb baryon into a Λc baryon and a pseudoscalar or vector meson in the framework of HQET. With the additional assumption of factorization the branching ratios and asymmetry parameters for various decay processes [Formula: see text] are obtained. Treating the s quark as heavy we have also applied HQET to study the decay process Λb→ΛJ/ψ and the estimated branching ratio for this process is lying within the present experimental limits.
A FORMULA FOR THE HOPPING EXPANSION OF EIGHT-VERTEX MODELS COUPLED TO AN EXTERNAL FIELD
Authors: GATTRINGER CHRISTOF
Published: April 2003

We study a generalized eight-vertex model where the vertices are coupled to a locally varying field. We rewrite the partition function as an integral over Grassmann variables. In this form it is possible to explicitly evaluate all terms of the hopping expansion. Applications of the resulting formula, in particular its relation to 2D lattice field theories with fermions are discussed.
SPIN AND SPIN–SPIN CORRELATIONS IN CHARGINO PAIR PRODUCTION AT FUTURE LINEAR e+e- COLLIDERS
Authors: LAFAGE V. , ISHIKAWA T. , KURIHARA Y. , KANEKO T. , KON T. , TANAKA H.
Published: April 2003

A possibility to measure the spin and spin–spin correlations of a chargino pair is investigated in the process [Formula: see text] at future linear-collider energies. The total and the differential cross sections are calculated by the [Formula: see text] system which allows for the full spin correlation. Experimental sensitivity of the measurements are examined by assuming the limited detector resolution, the initial state radiation and the beam–beam effect (beamstrahlung). It is found that generally the spin–spin correlation can only be measured with a lower sensitivity than the chargino spin itself. The dependence of the correlation measurements on the relevant SUSY parameters can be seen for a light [Formula: see text] case, but the situation becomes worse for a heavier [Formula: see text].
TWO-DIMENSIONAL (4,4) SUPERSYMMETRY AND NON-ABELIAN DUALITY
Authors: ASSAOUI F. , BENHAMOU N. , LHALLABI T.
Published: April 2003

The (4,4) supersymmetric dual gauge action of the two-dimensional (4,4) super-Yang–Mills theory is constructed and the corresponding gauge anomaly is expressed. The Abelian and non-Abelian T duality of the two-dimensional (4,4) supersymmetric sigma model are discussed.
A LOAD-BALANCED ALGORITHM FOR PARALLEL DIGITAL IMAGE WARPING
Authors: CONTASSOT-VIVIER SYLVAIN , MIGUET SERGE
Published: April 2003

This paper introduces and compares three parallel algorithms to compute general geometric image transformations on MIMD machines. We propose three variants of a parallel general scheme. We focus on the load balancing and the data redistributions. Experimental results are reported and compared. The implementation has been done using PPCM library allowing us to run the program over different parallel machines.

We compare logical communication schemes for message-passing machines. Since our parallel algorithm needs global communications such as multiscatters, we study the efficiency of two different logical topologies usable with PPCM.

These studies allow us to find the best combination of algorithm and virtual topology to use on a given parallel machine.
ONLINE HANDWRITING CHARACTER RECOGNITION METHOD USING DIRECTIONAL AND DIRECTION-CHANGE FEATURES
Authors: OKAMOTO MASAYOSHI , YAMAMOTO KAZUHIKO
Published: April 2003

We propose a new online recognition method to recognize handwritten cursive-style Japanese characters correctly. Our method simultaneously uses both directional features, otherwise known as offline features, and direction-change features which we designed as online features. The direction-change features express where in the mesh and in which direction the character's coordinates change. These features express both written strokes in the pen-down state and unwritten imaginary strokes in the pen-up state. The recognition rate was improved by our method over the traditional method using only directional features.
ON SOME CATEGORIES OF GAMES AND CORRESPONDING EQUILIBRIA
Authors: LAPITSKY VICTOR
Published: April 2003

Some new generalisations of non-cooperative games are introduced to study the categorical properties of non-cooperative games and equilibrium in them. The corresponding equilibria in the categories of these games are proved to be functors to the category of sets.
WEIGHTED MYERSON VALUE
Authors: HAERINGER GUILLAUME
Published: April 2003

The Myerson value [Myerson, (1977)] is defined for TU games on communication graphs. By dropping the symmetry argument used by Myerson, this paper generalises his concept, which is then shown to be equal to the weighted Shapley value. Two axiomatic characterisations are proposed: one including the weights in the axioms set, and one without.
DEMAND-INDUCED ENDOGENOUS PRICE LEADERSHIP
Authors: AMIR RABAH , GRILO ISABEL , JIN JIM
Published: April 2003

This paper provides general conditions on the direct demand functions in a Bertrand duopoly with differentiated substitute products and constant marginal costs, that allow an unambiguous ranking of firms' equilibrium payoffs between sequential play (with both order of moves) on the one hand, and simultaneous play on the other. The main results are that (i) when prices are strategic complements, both firms prefer sequential moves (with either order) to simultaneous moves, (ii) when prices are strategic substitutes, both firms prefer simultaneous moves to moving second in sequential play, and (iii) in the mixed strategic substitute/complement case, one firm is as in (i) and the other as in (ii). Thus, sequential moves would plausibly endogenously emerge in cases (i) and (iii), with one specified leader in the latter case. The analysis relies crucially on the theory of supermodular games, and is conducted at a high level of generality, dispensing with concavity-type assumptions, and taking into account both the issues of existence and possible non-uniqueness of the different equilibria involved.
NULL PLAYERS OUT? LINEAR VALUES FOR GAMES WITH VARIABLE SUPPORTS
Authors: DERKS JEAN J. M. , HALLER HANS H.
Published: April 2003

The paper studies the consequences of the Null Player Out (NPO) property for single-valued solutions on the class of cooperative games in characteristic function form. We allow for variable player populations (supports or carriers). A solution satisfies the NPO property, if elimination of a null player does not affect the payoffs of the other players. Our main emphasis lies on individual values. For linear values satisfying the null player property and a weak symmetry property, necessary and sufficient conditions for the NPO property are derived.
STATE-OF-ART REVIEW AND COMPILATION OF STUDIES ON PERFORATED THIN-WALLED STRUCTURES
Authors: SHANMUGAM N. E. , DHANALAKSHMI M.
Published: April 2003

Use of thin-walled steel sections in structures represents a tread further in the exploitation of structural form from its early ponderousness to the present day's trend towards tenuity. In the past seventy years, extensive experimental and analytical research has been carried out to examine the behavior of thin-walled structures containing openings. The experimental results have not been fully utilized by other researchers. As part of this review, an endeavor is made to cluster the experimental and analytical results with particular importance on plates, beams and plate girders and compression members and cellular structures containing perforations as an elucidative database using a handy spreadsheet program written in Visual Basic.
DAMPING AND NOISE IN QUANTUM MECHANICS
Authors: van KAMPEN N. G.
Published: April 2003

In a quantum system damping and noise enter through the coupling with an external large bath. The usual treatments computes the density matrix of the system by expanding in the coupling strength to the bath and averaging over the bath. The result, however, is known to be unacceptable as it leads to negative probabilities. It is here proposed to study correlation functions rather than the density matrix itself. Equations for them are derived and compared with the result obtained by the usual method.
Assessment of an Age-Adjusted Warfarin Initiation Protocol
Authors: Roberts Gregory W , Helboe Trine , Nielsen Cathrine BM , Gallus Alex S , Jensen Iwona , Cosh David G , Eaton Vaughn S
Published: April 2003

OBJECTIVE:

To examine the time taken to reach a stable international normalized ratio (INR), as well as the incidence of overanticoagulation of an age-adjusted warfarin initiation protocol.

METHODS:

Inpatients and outpatients commencing warfarin therapy at 2 teaching hospitals were dosed according to the age-adjusted protocol. Data were collected prospectively.

MAIN OUTCOME MEASURES:

Time to reach a stable INR of 2–3 and the number of patients experiencing an INR ≥4 during the first week of warfarin therapy.

RESULTS:

Seventy-three patients were assessed; at the completion of the 4-day titration protocol, 63% had achieved a stable INR. After an additional 2 days of empiric dosage adjustment by the attending physician, 86% of the subjects demonstrated a stable INR. Five patients (7%) experienced an INR ≥4. These patients had a nonsignificant trend toward a lower plasma albumin level compared with other patients (p = 0.057, Student's t-test). The INR-driven dose adjustments on days 3 and 4 of this protocol coped with other variables that have been shown to affect maintenance warfarin dosing. These included weight, gender, pharmacologic factors affecting clearance, and the presence of certain predesignated risk factors.

CONCLUSIONS:

The age-adjusted dosing protocol rapidly achieved a stable INR with minimal overanticoagulation. Patients with low serum albumin levels (<3.0 g/dL) may be sensitive to the effects of warfarin during the loading phase.
Milk Transfer and Neonatal Safety of Tacrolimus
Authors: French Amy E , Soldin Steven J , Soldin Offie P , Koren Gideon
Published: April 2003

OBJECTIVE:

To report the first case of tacrolimus measurement in human milk following maternal dosing in a woman who breast-fed while taking the medication.

CASE REPORT:

A 32-year-old white woman who had taken tacrolimus 0.1 mg/kg/d throughout pregnancy contacted the Motherisk Program at 35 weeks' gestation inquiring about the safety of breast-feeding during maternal tacrolimus therapy. After benefit–risk assessment, the mother decided to breast-feed the baby.

METHODS:

Manually expressed milk samples were collected over 12 hours following the first tacrolimus dose of the day; pre-dosing and 1-hour post-dosing blood concentrations were also determined. The samples were analyzed for tacrolimus by tandem-mass spectrometry. Breast milk and blood samples were collected at steady-state.

RESULTS:

The highest and mean concentrations of tacrolimus in milk were 0.57 and 0.429 ng/mL, respectively. From these measurements, the exclusively breast-fed infant would ingest, on average, 0.06 μg/kg/d, which corresponds to 0.06% of the mother's weight-adjusted dose. Given the low oral bioavailability of tacrolimus, the maximum amount the baby would receive is 0.02% of the mother's weight-adjusted dose. The milk-to-blood ratios of tacrolimus at pre-dosing and 1-hour post-dosing concentrations were calculated to be 0.08 and 0.09, respectively. At 2.5 months of age, the infant was developing well both physically and neurologically.

COMMENT:

This report is the first to measure tacrolimus concentrations in established human milk using tandem-mass spectrometry to detect drug while the infant was exclusively breast-fed by the mother, and in which the infant's growth and development were reported.

CONCLUSIONS:

Our results suggest that maternal therapy with tacrolimus for liver transplant may be compatible with breast-feeding.
Valproic Acid–Induced Neutropenia
Authors: Vesta Kimi S , Medina Patrick J
Published: April 2003

OBJECTIVE:

To report a case of severe neutropenia caused by valproic acid (VPA).

CASE SUMMARY:

A 56-year-old white woman with an infectious brain abscess causing tonic–clonic seizure activity was treated with VPA. She developed severe neutropenia after 2 days of VPA therapy. The absolute neutrophil count reached a nadir of 47 cells/mm3 during VPA use and returned to normal upon its discontinuation.

DISCUSSION:

VPA is considered to be a well-tolerated antiepileptic drug. While neutropenia has been reported, it has been mild and transient. This patient developed severe neutropenia during effective treatment with VPA, making her significantly susceptible to infection. The Naranjo probability scale indicates VPA as the probable cause of neutropenia in this case.

CONCLUSIONS:

This report of severe neutropenia caused by VPA emphasizes the importance of monitoring complete blood cell counts during therapy with this agent.
An observational study of multiple cloud head structure in the FASTEX IOP 16 cyclone
Authors: Roberts N. M. , Forbes R. M.
Published: April 2003

Radar, dropsonde, aircraft and satellite data obtained during a FASTEX intensive observing period are combined to give a unique description of multiple cloud heads in a rapidly developing mid‐latitude cyclone. The cloud heads are shown to be associated with stacked slantwise frontal circulations with ascent rates of around 10 cm/s. Copyright © 2002 Royal Meteorological Society.
Spectral differences between a single gravity shear wave and a continuous superposition of modes
Authors: Pulido Manuel
Published: April 2003

A continuous superposition of gravity waves, propagating upward in a shearing background wind, is analyzed. Starting from the gravity wave equations, it is proven, analytically and numerically, that a uniform spectrum has a resultant Doppler‐shifted power spectrum with a −3 power law at large vertical wavenumber contrasting with the −1 power law that characterizes the power spectrum of the monochromatic wave perturbation profile. The preliminary results presented here show that, assuming conservative propagation (no dissipative processes), the Doppler shifting effect can account for observations. Copyright © 2003 Royal Meteorological Society.
Multicentury-Scale Records of Carbonate (Hydrographic?) Variability on the Northern Iceland Margin over the Last 5000 Years
Authors: Andrews J.T. , Helgadottir Gudrun , Geirsdottir Aslaug , Jennings Anne E.
Published: April 2003

The waters off northern Iceland are subjected to extreme hydrographic variability on annual to decadal timescales. In years when cold low-salinity water moves coastward and sea ice is prevalent (i.e., the late 1960s), marine productivity of surface waters is low because the water column is well stratified. In the opposite oceanographic mode, warm, salty Atlantic Water dominates the shelf and vertical mixing results in high productivity. We track these two contrasting modes by measuring the carbonate content of marine sediments, a proxy for productivity, in three cores from northern Iceland. The fjord record (B997-328PC) is anchored by eleven 14C AMS dates and has a resolution of one sample every 50 yr. Thirteen oscillations occurred over the last 4800 cal yr with an average length of 370 yr; these are superimposed on a long-term decrease in net carbonate accumulation. The Little Ice Age is marked by the largest decrease in carbonate content and in flux, with smaller minima at 2300 and 3000 cal yr B.P. Marked peaks in carbonate (optima) occurred at 2000 and 3800 cal yr B.P. The carbonate record from B997-328PC can be correlated with records on the inner shelf (B997-330PC) and midshelf (B997-327PC), indicating that significant regional changes in oceanography occurred at the southern margin of the Norwegian–Greenland Sea. The marine carbonate fluctuations closely track temperature reconstructions from the Greenland Summit site for the last 2000 cal yr and show similar, but slightly offset, oscillations between 2000 and ca. 4800 cal yr B.P.
Quantitative Reconstruction of Younger Dryas to Mid-Holocene Paleoclimates at Le Locle, Swiss Jura, Using Pollen and Lake-Level Data
Authors: Magny Michel , Guiot Joël , Schoellammer Patrick
Published: April 2003

Pollen and lake-level data from Le Locle in the Swiss Jura were used to quantitatively reconstruct climatic parameters for the Younger Dryas event and the first half of the Holocene period. The Younger Dryas cold event at Le Locle was characterized by (i) a general trend toward a slight increase in summer temperature and a decrease in annual precipitation and (ii) a marked drying phase at ca. 11,900 cal yr B.P. that occurred between two wetter ones. Further phases of major deficit in moisture occured at ca. 11,500 cal yr B.P. (Younger Dryas-Holocene transition), 10,800 cal yr B.P., 8700 cal yr B.P., and 6500 cal yr B.P. Climatic parameters reconstructed here suggest that phases of higher lake level developing at ca. 12,500–12,000, 11,750–11,600, 11,200–10,900 (synchronous with the Preboreal oscillation), 10,400–8900, 8400–8300 (possibly related to the 8200 yr event), and 7800–7000 cal yr B.P. coincided with an increase in annual precipitation, a decrease in summer temperature, and a shorter growing season. Conversely, periods of low lake level corresponded to a decrease in annual precipitation, an increase in summer temperature, and a longer growing season. This general pattern could have resulted from alternate southward-northward displacements of the Atlantic Westerly Jet.
Paleoclimatic Reconstruction Using the Correlation in δ18O of Hackberry Carbonate and Environmental Water, North America
Authors: Jahren A. Hope , Amundson Ronald , Kendall Carol , Wigand Peter
Published: April 2003

Celtissp. (commonly known as “hackberry”) fruits were collected from 101 North American sites located in 13 states and one Canadian province between the years of 1979–1994. The biomineralized carbonate endocarp of the hackberry, which is a common botanical fossil found throughout the Quaternary sediments of the Great Plains, was analyzed for its δ18O value and plotted against the δ18O value of site environmental water to demonstrate the potential of the hackberry as a paleoclimate indicator. This correlation was reinforced by intensive studies on extracted tissue-water δ18O value and hackberry endocarp carbonate δ18O value from three trees in Sterling, Colorado. The observed correlation in the large data set between hackberry endocarp carbonate δ18O value and environmental water is [endocarp δ18O=38.56+0.69×environmental water δ18O] (R=0.88;R2=0.78;pvalue<0.0001). The relation of the hackberry carbonate to temperature in the Great Plains was the following: (average daily-maximum growing season temperature [°C])=6.33+0.67 (δ18O of endocarp carbonate) (R=0.73;R2=0.54;pvalue=0.0133). The δ18O value of early Holocene fossil hackberry carbonate in the Pintwater Cave, southern Nevada, suggested precipitation δ18O values more positive than today (∼−4‰ early Holocene vs ∼−9 to −10‰ today). This shift, combined with paleobotanical data, suggests an influx of summer monsoonal moisture to this region in the early Holocene. Alternatively, the more positive δ18O values could be viewed as suggestive of warmer temperatures, although the direct use of Great Plains hackberry/temperature relationships to the Great Basin is of debatable value.
A critical mutation in both WT1 alleles is not sufficient to cause Wilms' tumor
Authors: Kikuchi Haruhito , Akasaka Yoshikiyo , Kurosawa Yoshihiro , Yoneyama Hiroshi , Kato Shingo , Hata Jun-ichi
Published: April 2003

The WT1 gene is a tumor suppresser gene for Wilms' tumor (WT). Inactivation of both alleles has been proposed as the cause of WT. We encountered a patient with Denys‐Drash syndrome associated with WT whose WT1 gene had a homozygous point mutation not only in WT but also in renal tissue adjacent to the WT and in the germline. These findings indicate that factor(s) other than the loss of WT1 are required for WT to develop.
Cytochrome P450 CYP3A5 in the human anterior pituitary gland
Authors: Murray Graeme I. , Pritchard Stuart , Melvin William T. , Burke M.Danny
Published: April 2003

The cytochromes P450 are a key group of enzymes involved in the metabolism of xenobiotics and several biologically active endogenous compounds. The expression of CYP3A5 has been identified by reverse transcriptase‐polymerase chain reaction in human pituitary gland and shown by immunohistochemistry to be localized to growth hormone containing cells of the anterior pituitary gland. This is the first direct identification of an individual P450 subfamily in the pituitary gland and the presence of CYP3A in the pituitary gland may play a role in regulating growth hormone secretion.
Amyloid beta protein (25–35) stimulation of phospholipases A, C and D activities of LA‐N‐2 cells
Authors: Singh Indrapal N. , McCartney Douglas G. , Kanfer Julian N.
Published: April 2003

[3H]Myristic acid prelabeled LA‐N‐2 cells were exposed to varying concentrations of amyloid beta protein (25–35), from 20 to 250 μg/ml, and the activation of phospholipases A and D estimated. A progressive increase in phosphatidylethanol formation, a measure of phospholipase D activity, and of free fatty acid release, a measure of phospholipase A activity, was observed over a time‐course of 60 min. [3H]Inositol prelabeled LA‐N‐2 cells were exposed to varying concentrations of AβP, from 20 to 125 μg/ml, and phospholipase C activation was measured. There was an increased release of inositol phosphates in the presence of amyloid beta protein as a function of incubation time. The effects of adrenergic, metabotropic amino acid and bombesin antagonists on the AβP mediated stimulation of phospholipase C activity was investigated. Propranolol, a β adrenergic antagonist, 7‐chlorokynurenic acid, a metabotropic amino acid antagonist, and [Tyr4‐d‐Phe12]bombesin, a bombesin antagonist, blunted the AβP stimulation of phospholipase C activity in [3H]inositol prelabeled L‐AN‐2 cells. This suggests that amyloid beta protein activation of phospholipase C may be receptor mediated. The phospholipase C inhibitor U 71322 prevented the activation of phospholipase C by AβP. However, this activation was not effected by tocopherol, propylgallate, or vitamin C.
Calponin reduces shortening velocity in skinned taenia coli smooth muscle fibres
Authors: Jaworowski Åsa , Anderson Kurt I. , Arner Anders , Engström Martin , Gimona Mario , Strasser Peter , Small J.Victor
Published: April 2003

Calponin (4.1–5.9 μM, pig stomach) inhibited maximal shortening velocity (V
max) by 20–25% with only minor influence on force in skinned smooth muscle from guinea‐pig taenia coli activated at different Ca2+ levels and with thiophosphorylation. Similar results were obtained with a fragment of the N‐terminal 1–228 amino acids engineered using a mouse cDNA construct (5.4 μM). Both the native calponin and the fragment inhibited actin filament sliding in a graded manner in an in vitro motility assay. We conclude that calponin influences the kinetics of the actin‐myosin interaction in the organised smooth muscle contractile system and that engineered fragments of calponin can be used to probe its action in muscle fibres. The effects can be due to an introduction of an internal load during filament sliding, possibly by decreasing the detachment rates and increasing the cross‐bridge time spent in the attached state.
Ecotin is a potent inhibitor of the contact system proteases factor XIIa and plasma kallikrein
Authors: Ulmer Jana S. , Lindquist Robert N. , Dennis Mark S. , Lazarus Robert A.
Published: April 2003

Ecotin, a serine protease inhibitor found in the periplasm of Escherichia coli, has been characterized as a potent reversible tight‐binding inhibitor of the human contact activation proteases factor XIIa (FXIIa) and plasma kallikrein, having K
i values of 89 pM and 163 pM, respectively. Ecotin also inhibited human leukocyte elastase (HLE) with high affinity (K
i = 55 pM). The association rate constants k
on for FXIIa and kallikrein were 5.3 × 105 M−1·s−1 and 2.9 × 105 M−1·s−1, respectively. The dissociation rate constant k
off for kallikrein, measured in the presence of HLE to prevent reassociation, was 6.3 × 10−5 s−1; the k
off for ecotin with FXIIa was 4.7 × 10−5 s−1. Both FXIIa and kallikrein cleaved ecotin slowly at pH 5.0, identifying Met‐84 as the P1 residue. The potent anticoagulant effect by ecotin is explained by the coincident inhibition of FXIIa, kallikrein, and FXa and suggests that it may be useful in the study of inflammatory or thrombotic disorders such as sepsis or cardiopulmonary bypass.
PTF1 encodes an essential protein in Saccharomyces cerevisiae, which shows strong homology with a new putative family of PPIases
Authors: Hani J. , Stumpf G. , Domdey H.
Published: April 2003

Complementation of a temperature sensitive mutant of the yeast Saccharomyces cerevisiae resulted in the isolation of PTF1 (processing/termination factor 1), an essential gene encoding a putative 3′‐end processing or transcription termination factor of pre‐mRNAs. Ptf1p shows significant homology to a newly discovered family of PPIases. This family is characterized by its insensitivity to immunosuppressive drugs and the lack of homology with cyclophilins and FK‐506 binding proteins [Rahfeld et al. (1994) FEBS Lett. 352, 180–184]. Should Ptf1p display PPIase activity, it would be the first characterized, eukaryotic member of this putative family, which is essential for growth.
Identification and structural characterization of a mannose‐6‐phosphate containing oligomannosidic N‐glycan from human erythropoietin secreted by recombinant BHK‐21 cells
Authors: Nimtz Manfred , Wray Victor , Rüdiger Angelika , Conradt Harald S.
Published: April 2003

A sialidase resistant mono‐charged N‐glycan was isolated from glycosylation site I (Asn‐24) of recombinant human eruthropoietin expressed from baby hamster kidney (BHK‐21) cells and constituted approximately 2–4% of the oligosaccharide material at this glycosylation site. Mass spectrometry and both 1‐ and 2‐dimensional NMR techniques revealed a high mannose type structure (Man6) with a phospho‐diesterbridged N‐acetylglucosamine as follows:
Regulation of cell surface GLUT1, GLUT3, and GLUT4 by insulin and IGF‐I in L6 myotubes
Authors: Wilson Cindy M. , Mitsumoto Yasuhide , Maher Fran , Klip Amira
Published: April 2003

The effects of insulin and IGF‐I on the cell surface quantities of GLUT1, GLUT3 and GLUT4 glucose transporters in L6 myotubes were determined with the exofacial bis‐mannose phololabel (ATB‐BMPA). In basal cells, an equal molar quantity of each transporter isoform was found at the cell surface. Insulin stimulated the translocation of all three glucose transporter isoforms to the plasma membrane fraction from the light microsome fraction, resulting in equal molar quantities on the cell surface. IGF‐I stimulated a similar translocation of all isoforms, augmented by an increase in surface GLUT3 as assessed by ATB‐BMPA.
Three‐dimensional crystals of cytochrome‐coxidase fromThermus thermophilusdiffracting to 3.8 Å resolution
Authors: Soulimane Tewfik , Gohlke Ulrich , Huber Robert , Buse Gerhard
Published: April 2003

Theba3‐type cytochrome‐coxidase fromThermus thermophilushas been crystallized in its native form. Crystallization was achieved by the batch and the vapour diffusion sitting drop methods using polyethylene glycol monomethyl ether 2000 as precipitating agent in the presence of octyl‐β‐d‐thioglucoside as detergent. The crystals diffract to 3.8 Å, belong to the space group P2 or P21and have unit cell dimensions of;;andβ= 104.4°. The asymmetric unit contains twoba3‐type oxidase molecules.
hCAP‐18, a cathelin/pro‐bactenecin‐like protein of human neutrophil specific granules
Authors: Cowland Jack B. , Johnsen Anders H. , Borregaard Niels
Published: April 2003

A 19 kDa protein was identified in specific granules of human neutrophils. A full‐length cDNA clone was isolated from a human CML cDNA library, based on amino‐acid sequences of isolated tryptic fragments. This clone includes the recently identified cDNA for FALL‐39/CAP‐18. Aminoacid sequences of proteolytic fragments derived both from the conserved N‐terminal cathelin‐like region and the highly variable C‐terminal region characteristic of this family of bactericidal, LPS binding proteins, were in complete agreement with the sequence deduced from the cDNA. Thus, the 19 kDa protein is hCAP‐18, stored as a ‘pro‐peptide’ in specific granules.
A particularly labile Asp‐Pro bond in the green mamba muscarinic toxin MTX2. Effect of protein conformation on the rate of cleavage
Authors: Ségalas Isabelle , Thai Robert , Claudio Vita Renée Ménez
Published: April 2003

The single Asp53‐Pro54 bond of the MTX2 toxin from the mamba snake Dendroaspis angusticeps is rapidly and efficiently cleaved in acidic solution (pH 1.5–2.5) at 45°C. Unfolding of the toxin slows down the cleavage reaction by several times. Modelling studies indicate that the native toxin conformation can catalyse the Asp53‐Pro54 bond cleavage. The implications of this study are: (i) cleavage of Asp‐Pro bond for sequence determination may occur better in absence than in presence of denaturant, (ii) mild acid conditions, commonly used in NMR structure determinations, may irreversibly affect the structural integrity of Asp‐‐Pro containing peptides and proteins.
Identification of Glu173 as the critical amino acid residue for the ADP‐ribosyltransferase activity of Clostridium botulinum C3 exoenzyme
Authors: Saito Yuji , Nemoto Yasuo , Ishizaki Toshimasa , Watanabe Naoki , Morii Narito , Narumiya Shuh
Published: April 2003

Clostridium botulinum C3 exoenzyme specifically ADP‐ribosylates rho‐p21 in eukaryotic cells. Trp18 and Glu173 of this enzyme were substituted with other amino acids via site‐directed mutagenesis. All substitutions at Glu173 caused a significant reduction in affinity for NAD and diminished ADP‐ribosyltransferase activity. On the other hand, the activity of enzymes with the substitution at Trp18 remained intact. Swiss 3T3 cells treated with the enzyme with the Trp18 substitution showed the typical morphologic changes of the C3 exoenzyme phenotype. In contrast, no changes were found in cells incubated with the Glu173‐substituted enzyme. These results indicate that the Glu173 residue of the C3 exoenzyme plays a key role in interacting with NAD and in expression of ADP‐ribosyltransferase activity, which is essential for the phenotypic change by C3 exoenzyme treatment.
Influence of nucleotides on the secondary structure and on the thermal stability of mitochondrial F1 visualized by infrared spectroscopy
Authors: Cladera Josep , Villaverde Joaquim , Hartog Aloysius F. , Padrós Esteve , Berden Jan A. , Rigaud Jean-Louis , Duñach Mireia
Published: April 2003

We have studied the secondary structure of mitochondrial F1 using infrared spectroscopy. Our results show that in the absence of added nucleotides this complex contains similar percentages of α‐helices, β‐structures and reverse turns (30%, 28% and 31%, respectively). The influence of ADP and ATP on the different types of secondary structure was determined; when all the nucleotide‐binding sites were occupied, small but reproducible changes were observed, corresponding to a decrease in β‐structure and an increase in α‐helix and reverse turns. The effect of nucleotide binding on the thermal stability of F1 was also studied; the thermal denaturation temperature, 55°C, was increased by 11°C and 7°C by ATP and ADP, respectively. These results indicate that nucleotide binding affects the secondary structure of F1, stabilizing the complex.
Identification and characterization of two isoforms of an endothelin‐converting enzyme‐1
Authors: Shimada Kohei , Takahashi Masaaki , Ikeda Masahiro , Tanzawa Kazuhiko
Published: April 2003

We report the cloning and sequencing of 5′‐terminal region of a β form of rat ECE‐1 cDNA which is different only in its N‐terminal amino‐acid sequence to the cDNA we have cloned previously (α form [K. Shimada et al. (1994) J. Biol. Chem. 269, 18275–18278]). No significant difference was found in the specific activity and substrate specificity between the two isoforms. The expression level of ECE‐1α mRNA was higher than that of ECE‐1β in various rat cells and tissues, suggesting that the physiologically important isoform is ECE‐1α. The present findings verified the presence of two forms of ECE‐1 over many species, which are created probably through alternative splicing.
Apoptosis, DNA damage and ubiquitin expression in normal and mdx muscle fibers after exercise
Authors: Sandri Marco , Carraro Ugo , Podhorska-Okolov Marzena , Rizzi Corrado , Arslan Paola , Monti Daniela , Franceschi Claudio
Published: April 2003

The current view indicates that after eccentric exercise myofibers are mechanically damaged and therefore an inflammatory and necrotic process occurs. In the present paper we examine the possibility that apoptosis plays a role in normal and dystrophin‐deficient muscles after running. We analysed for apoptosis normal and dystrophin‐deficient mouse muscles after a night of spontaneous wheel‐running followed by two days of rest. Terminal deoxynucleotidyl transferase‐mediated endlabeling of DNA in nuclei in tissue sections and gel electrophoresis of extracted DNA showed the presence of fragmented DNA. Furthermore, ubiquitin, a protein whose appearance is related to apoptosis, increased in muscles of both dystrophic and normal runner mice. The present findings which confirm that DNA damage is absent in muscles of sedentary mice but present in muscles of runner mice offer a new hypothesis on early events of muscle damage.
The MIG1 repressor from Kluyveromyces lactis: cloning, sequencing and functional analysis in Saccharomyces cerevisiae
Authors: Cassart Jean-Pol , Georis Isabelle , Östling Jonas , Ronne Hans , Vandenhaute Jean
Published: April 2003

Sequence comparisons between Saccharomyces cerevisiae ScMig1 and Aspergillus nidulans CREA proteins allowed us to design two sets of degenerate primers from the conserved zinc finger loops. PCR amplification on Kluyveromyces marxianus and K. lactis genomic DNA yielded single products with sequences closely related to each other and to the corresponding regions of ScMig1 and CREA. The KIMIGI gene of K. lactis was cloned from a genomic library using the K. marxianus PCR fragment as probe. KIMIGI encodes a 474‐amino acid protein 55% similar to ScMig1. Besides their highly conserved zinc fingers, the two proteins display short conserved motifs of possible significance in glucose repression. Heterologous complementation of a mig1 mutant of S. cerevisiae by the K. lactis gene demonstrates that the function of the Mig1 protein is conserved in these two distantly related yeasts.
The neuroendocrine chaperone 7B2 can enhance in vitro POMC cleavage by prohormone convertase PC2
Authors: Braks Joanna A.M. , Martens Gerard J.M.
Published: April 2003

We previously showed that the neuroendocrine polypeptide 7B2 transiently interacts with prohormone convertase PC2 in the secretory pathway of neuroendocrine cells. Here we demonstrate that the processed, but not the intact, form of 7B2 can enhance the in vitro cleavage of newly synthesized prohormone proopiomelanocortin (POMC) in lysates of Xenopus intermediate pituitary cells. PC2 is presumably the cleavage enzyme involved since intact 7B2 abolishes the enhancing effect of processed 7B2 and is known to act as a specific inhibitor of PC2. Furthermore, processed 7B2 stimulates in vitro POMC cleavage by immunopurified Xenopus PC2. Our results indicate that 7B2 can display chaperone activity towards PC2.
A β‐subclass phosphatidylinositol‐specific phospholipase C from squid (Loligo forbesi) photoreceptors exhibiting a truncated C‐terminus
Authors: Carne Alan , McGregor Richard A. , Bhatia Jeetendra , Sivaprasadarao Asipu , Keen Jeff N. , Davies Anthony , Findlay John B.C.
Published: April 2003

A PCR‐based strategy has been used to isolate a full length cDNA encoding a phosphatidylinositol‐specific phospholipase C from a sized cDNA squid (Loligo forbesi) retinal library. The predicted protein sequence contains 875 amino acids, with calculated M
r 98,181, and has marked similarity with PLC β‐isoforms, including conservation of the ‘X’ and ‘Y’ regions. It is unique in having a major C‐terminal truncation. A major protein of apparent M
r 120,000 estimated by SDS‐PAGE has been isolated from squid photoreceptors and identified by partial protein sequence analysis to correspond to the protein sequence predicted from the cDNA clone. This protein has been shown to hydrolyse phosphatidylinositol 4,5‐bisphosphate. It is not yet clear whether this represents the major light‐activated PLC in squid vision.
Synthesis and biological evaluation of substituted phosphate triester alkyl lyso phospholipids (ALPs) as novel potential anti‐neoplastic agents
Authors: McGuigan Christopher , Wang Yikang , Riley Patrick A.
Published: April 2003

Phosphate triester derivatives of the anti‐neoplastic alkyl lyso phospholipid (ALP) have been prepared as novel potential therapeutic agents. In particular, symmetrical phosphate triesters have been prepared, using phosphorochloridate chemistry. The compounds have been fully characterised by a range of techniques, and assayed for their inhibition of DNA synthesis by mammalian cells in culture. The compounds are generally inhibitory towards DNA synthesis in the μM range. However, the magnitude of the effect varies greatly with the phosphate structure; alkynyl and glycol substituted phosphates being especially potent.
Regulation of intracellular pH by cell‐cell adhesive interactions
Authors: Galkina S.I. , Sud'ina G.F. , Dergacheva G.B. , Margolis L.B.
Published: April 2003

Inhibitors of phospholipase A2 (4‐bromophenacyl‐bromide), phospholipase C (neomycin) and protein kinase C (H‐7) dramatically change the way the pHi is modulated by local cell density. It is suggested that cell‐cell interactions regulate cell activities via modulation of pHi, which is under positive control from phospholipase A2 and under negative control from protein kinase C.
Casocidin‐I: a casein‐αs2 derived peptide exhibits antibacterial activity
Authors: Zucht Hans-Dieter , Raida Manfred , Adermann Knut , Mägert Hans-Jürgen , Forssmann Wolf-Georg
Published: April 2003

Here we report the isolation and characterization of an antibacterial peptide from bovine milk inhibiting the growth of Escherichia coli, and Staphylococcus carnosus. The primary structure of the peptide was revealed as a 39‐amino‐acid‐containing fragment of bovine αs2‐casein (position 165–203) by means of Edman amino acid sequencing and mass spectrometry. Since human milk does not contain any casein‐αs2, these findings could explain the different influence of human and bovine milk on the gastrointestinal flora of the suckling.
Classification of multi‐helical DNA‐binding domains and application to predict the DBD structures of σ factor, LysR, OmpR/PhoB, CENP‐B, Rap1, and XylS/Ada/AraC
Authors: Suzuki Masashi , Brenner Steven E.
Published: April 2003

We have systematically compared structures of multihelical DNA‐binding domains (DBDs) which have been determined by crystallography or NMR spectroscopy. All the known multi‐helical DBDs are very similar. The core of these structures consists of two α‐helices in the helix‐turn‐helix combination, associated with one or two other helices. The structures can be classified according to either additional structural compositions or the configuration of the helices. Many DBDs, whose structures are currently unknown, have sequences which resemble those of known structures, permitting outlines of the new structures to be predicted.
NOR‐2 (neuron‐derived orphan receptor), a brain zinc finger protein, is highly induced during liver regeneration
Authors: Petropoulos Isabelle , Part Dominique , Ochoa Alberto , Zakin Mario M. , Lamas Eugénia
Published: April 2003

Zinc‐finger proteins are involved in several cellular processes. Some of these proteins are implicated in the primary cellular response in regenerating liver and mitogen‐stimulated cells. Using a rat cDNA brain library, we have isolated a clone designated NOR‐2, encoding a protein containing two zinc‐finger motifs and whose expression is highly induced during G0/G1 transition. We analysed the expression of NOR‐2 mRNAs during early growth in regenerating liver and in both insulin‐stimulated H4‐II cells and pheochromocytoma‐derived cell line PC12 treated by NGF. In these systems, there is an early, rapid and transient accumulation of NOR‐2 mRNAs. The induction of NOR‐2 mRNAs does not require de novo protein synthesis, since it is not prevented by cycloheximide treatment. Mobility shift assays show that NOR‐2 protein binds to NBRE, a target sequence for r‐NGFI‐B family. Structurally, NOR‐2 is closely related to the recently identified NOR‐1 factor. Therefore, like NOR‐1, NOR‐2 belongs to the r‐NGFI‐B sub‐family of nuclear receptors superfamily.
Lasp‐1 (MLN 50) defines a new LIM protein subfamily characterized by the association of LIM and SH3 domains
Authors: Tomasetto Catherine , Moog-Lutz Christel , Régnier Catherine H. , Schreiber Valérie , Basset Paul , Rio Marie-Christine
Published: April 2003

MLN 50 was previously identified in a cDNA library of breast cancer metastasis. In this study, we show that MLN 50, which is expressed at a basal level in normal tissues, is overexpressed in 8% of human breast carcinomas most often together with c‐erbB‐2. MLN 50 cDNA encodes a putative protein of 261 residues, named Lasp‐1 (IM and H3 protein) since it contains a LIM motif and a domain of Src homology region 3 (SH3) at the amino‐ and the C‐terminal parts of the protein, respectively. Thus, Lasp‐1 defines a new LIM protein subfamily.
Cloning and sequencing of a cDNA encoding rat d‐dopachrome tautomerase
Authors: Zhang Miao , Åman Pierre , Grubb Anders , Panagopoulos Ioannis , Hindemith Annika , Rosengren Evald , Rorsman Hans
Published: April 2003

An enzyme which converts d‐dopachrome into 5,6‐dihydroxyindole has recently been isolated from rat liver. Enzymatic d‐dopachrome conversion has been observed in extracts from all tissues examined of several species, including man. We have now cloned and sequenced a 628 bp long cDNA encoding the enzyme provisionally called d‐dopachrome tautomerase. The cDNA was isolated by 3′ and 5′ rapid amplification and cloning of cDNA ends (RACE) from rat liver cells using degenerate oligonucleotide primers, deduced from the N‐terminal peptide sequence of d‐dopachrome tautomerase. The cDNA contains an open reading frame encoding 118 amino acids. Edman degradation of intact and of trypsin degraded d‐dopachrome tautomerase fragments gave information on and corroborated 67% of the deduced protein sequence. A homology search in the EST database found a human cDNA encoding a peptide sharing 66% homology with the rat enzyme. The rat d‐dopachrome tautomerase shares 27% homology with the rat macrophage migration inhibitory factor (MIF).