Computer Simulations of I-Center Annealing in KCl and KBr Crystals. Theoretical Interpretation of Thermostimulated Experiments

1995

Results of computer simulations of the kinetics of correlated annealing of pairs of close α–I and F–I centers in KCI and KBr crystals, enhanced by I-center diffusion and Coulomb or elastic attractions, respectively, are presented. Special attention is paid to the conditions under which multi-stage annealing stages arise as it has been observed experimentally more than once. Our general conclusions are: (i) a weak elastic interaction affects the recombination kinetics and the survival probability even for relatively well-separated F–I pairs, the more so is true for the case of Coulomb attraction between charged α–I pairs; (ii) the multi-step (kink) structure arises only for close (typically,…

A phenomenological quark current for the study of the polarized structure function of the nucleon

1995

In the context of the quark model, a phenomenological expression for the electromagnetic interaction is derived in order to study the polarized structure function of the nucleon. The DHG value without hyperfine corrections and the asymptotic behaviour are reproduced.

A Novel Chainlike Heteropolyanion Formed by Keggin Units: Synthesis and Structure of(ET)8n[PMnW11O39]n· 2nH2O

1995

Systematic Study of Horizontal Gauge Theories

1995

We analyze all the possible continuous horizontal gauge groups G_H in relation with their possibility to explain m_b<<m_t. We assume that the only effective fermionic degrees of freedom correspond to the known fermions but allow the possibility of adding a right handed neutrino to each family. We assume that the Higgs fields which generate masses for these fermions, trough renormalizable Yukawa couplings, transform as an irreducible representation of SU(3)_c\otimesSU(2)_L\otimesU(1)_Y\otimesG_H. Under these assumptions we find two U(1)_H or U(1)_{H1}\otimesU(1)_{H2} models free of anomalies and able to guarantee that only the top has a renormalizable mass-generating Yukawa coupling.

Health and sensory motivations in the choice of four light food products for french consumers

1995

International audience

The dynamics of preferences for salty flavored crackers: the predictive value of a laboratory boredom test

1995

4 graph.; International audience

Consumer perceptions of traditionally-made hams

1995

International audience

Reproductive costs and litter size in the bank vole.

1995

The potential reproductive costs for free-ranging bank vole (Clethrionomys glareolus) offspring and mothers were assessed by manipulating litter size and by determining the effects of nursing varied numbers of offspring. Litter enlargement did not increase the number of weanlings per mother. The mass of juveniles was significantly lower in the enlarged litters and higher in the reduced litters, compared to the control group. However, the survival of juveniles from weaning aged three months did not depend on their mass at weaning. Data from a previous study (Mappes et al. 1995) indicated that a higher mass at weaning may increase juveniles' abilities to maturate and breed during their summer…

Immunohistochemical Detection of Binding of Cryia Crystal Proteins of Bacillus thuringiensis in Highly Resistant Strains of Plutella xylostella (L.) …

1995

We detected binding of insecticidal crystal proteins from Bacillus thuringiensis in one susceptible strain and six resistant strains of diamondback moth, Plutella xylostella, from Hawaii. Immunohistochemical tests with tissue sections from larval midguts showed specific binding of CryIA(a), CryIA(b), and CryIA(c) to brush border membranes. CryIE, which is not toxic to P. xylostella, did not bind to midgut tissues. Larvae from one of the resistant strains ingested extremely high concentrations of a commercial formulation containing the three CryIA proteins without suffering midgut cell damage or mortality. This same resistant strain had previously been found to have greatly reduced binding o…

Renormalized Proton-Neutron Quasiparticle Random-Phase Approximation and Its Application to Double Beta Decay

1995

A self-consistent method of treating excitations of the proton-neutron quasiparticle random-phase approximation is presented. The non-self-consistent methods violate the Pauli exclusion principle and lead to an eventual collapse of the ground state. This behavior renders a reliable calculation of the nuclear matrix elements, relevant for the prediction of double-beta-decay half-lives, difficult. The present formalism promotes the Pauli exclusion principle and avoids the collapse of the double-beta-decay matrix elements. We have applied this formalism to the double beta decay of ${}^{100}$Mo.

Breathing solitary waves in a Sine-Gordon two-dimensional lattice.

1995

We study theoretically and numerically the dynamical behavior of a two-dimensional sine-Gordon lattice. We show that, via modulational instability, an initial-low-amplitude plane wave can evolve spontaneously into moving localized modes with large amplitude. These nonlinear modes, with dimensions depending on the characteristic wavelengths of the instability, behave like breathing solitary waves and present particlelike properties.

Kuzovkov and Kotomin reply.

1995

Electronic-structure-induced deformations of liquid metal clusters

1995

Ab initio molecular dynamics is used to study deformations of sodium clusters at temperatures $500\cdots 1100$ K. Open-shell Na$_{14}$ cluster has two shape isomers, prolate and oblate, in the liquid state. The deformation is stabilized by opening a gap at the Fermi level. The closed-shell Na$_8$ remains magic also at the liquid state.

1H-NMR study of a cobalt-substituted blue copper protein: Pseudomonas aeruginosa Co(II)-azurin.

1995

Substitution of copper by cobalt in blue copper proteins gives a paramagnetic metalloderivative suitable for paramagnetic NMR studies. A thorough analysis of the 1H-NMR spectrum of Pseudomonas aeruginosa Co(II)-azurin is presented here. All the observable contact-shifted signals as well as many other paramagnetic signals from protons placed up to about 1.0 nm around the metal center, including some residues belonging to functionally important parts of the protein like the hydrophobic patch and the His35 region, have been assigned. The results obtained permit the detection and study of structural variations like those originated by the His35 ionization, and allow us to draw a feasible pictur…

Motion of an electric charge in a terrestrial laboratory.

1995

The equation of motion for a charge in an electromagnetic field is written in the Fermi coordinates of an observer moving with a constant acceleration g=9.8 m/${\mathrm{s}}^{2}$ (${10}^{\mathrm{\ensuremath{-}}18}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ in units such that c=1). This is involved in the equation of motion not only as a Newtonian term g\ensuremath{\rightarrow}, but also as a relativistic correction of the form ``-2(g\ensuremath{\rightarrow}\ensuremath{\cdot}v\ensuremath{\rightarrow})v\ensuremath{\rightarrow}.'' We have studied the effect of this term under the conditions of an accelerator of particles. To this end, we have considered a constant and uniform magnetic field, a…

Kinetics of streptolysin O self-assembly.

1995

Streptolysin O is a member of a family of membrane-damaging toxins that bind to cell membranes containing cholesterol and then polymerize to form large pores. We have examined the kinetics of toxin action using 125I-labelled streptolysin O. Binding of toxin monomers to membranes displays first-order kinetics and is reversible; the rate of desorption from red cells shows a marked dependence on temperature. To study oligomerization, toxin was bound to erythrocytes at 0 degrees C. Oligomer formation was then triggered by a sudden temperature shift and stopped by solubilization of membranes with deoxycholate. While at moderately high streptolysin O concentrations oligomerization behaves as a re…

Nitric oxide and sensory afferent neurones modulate the protective effects of low-dose endotoxin on rat gastric mucosal damage

1995

Pretreatment (1 h) with low doses (5-40 micrograms/kg i.p.) of Escherichia coli endotoxin dose dependently reduced the gastric mucosal damage induced by a 10 min challenge with 1 ml ethanol (50% and 100%) in conscious rats. Treatment with the nitric oxide synthesis inhibitor, NG-nitro-L-arginine methyl ester (L-NAME, 5 and 10 mg/kg i.p.), significantly inhibited the protective effects of endotoxin (40 micrograms/kg i.p.). The actions of L-NAME were reversed by the prior administration of L-arginine (100 mg/kg i.p.). The protective effects of endotoxin were not influenced by pretreatment with dexamethasone (5 mg/kg s.c. twice) or indomethacin (5 mg/kg s.c.). However, ablation of sensory affe…

Estimation of evapotranspiration using SVAT models and surface IR temperature

1995

Soil Vegetation Atmosphere Transfer (SVAT) models have been implemented to estimate energy and mass fluxes between soil, vegetation and atmosphere of various ecosystems. They can also simulate remote sensing data and in particular thermal infrared surface temperature. Usually, these models are simple, but they use realistic descriptions of radiative, turbulent and water transfers. These include description of stomatal control of transpiration fluxes. Some studies have shown that such models may be used to derive evapotranspiration from surface temperature, using inversion procedures. In this study, inversion of two different SVAT models are compared.

The multifractal character of the electronic states in disordered two-dimensional systems

1995

The nature of electronic states in disordered two-dimensional (2D) systems is investigated. With this aim, we present our calculations of both density of states and d.c. conductivity for square lattices modelling the Anderson Hamiltonian with on-site energies randomly chosen from a box distribution of width W. For weak disorder (W), the eigenfunctions calculated by means of the Lanczos diagonalization algorithm display spatial fluctuations reflecting their (multi)fractal behaviour. For increasing disorder the observed increase of the curdling of the wavefunction reflects its stronger localization. However, as a function of energy, the eigenstates at energy mod E mod /V approximately=1.5 are…

Cauchy Problem for Gott Spacetime

1995

Gott recently has constructed a spacetime modeled by two infinitely long, parallel cosmic strings which pass and gravitationally interact with each other. For large enough velocity, the spacetime will contain closed timelike curves. An explicit construction of the solution for a scalar field is presented in detail and a proof for the existence of such a solution is given for initial data satisfying conditions on an asymptotically null partial Cauchy surface. Solutions to smooth operators on the covering space are invariant under the isometry are shown to be pull back of solutions of the associated operator on the base space. Projection maps and translation operators for the covering space a…

Left-right symmetry breaking in NJL approach

1995

We study left-right symmetric models which contain only fermion and gauge boson fields and no elementary scalars. The Higgs bosons are generated dynamically through a set of gauge- and parity-invariant 4-fermion operators. It is shown that in a model with a composite bi-doublet and two triplet scalars there is no parity breaking at low energies, whereas in the model with two doublets instead of two triplets parity is broken automatically regardless of the choice of the parameters of the model. For phenomenologically allowed values of the right-handed scale a tumbling symmetry breaking mechanism is realized in which parity breaking at a high scale $\mu_R$ propagates down and eventually cause…

Synthesis and pharmacological evaluation of 2'-hydroxychalcones and flavones as inhibitors of inflammatory mediators generation.

1995

2'-Hydroxy-3,4-dimethoxy-3',4'-dimethylchalcone (3a), 2'-hydroxy-3',4',3,4-tetramethoxychalcone (3b), and their corresponding flavones, 3',4'-dimethoxy-7,8-dimethylflavone (4a) and 3',4',7,8-tetramethoxyflavone (4b), were prepared from 3,4-dimethoxycinnamic acid and the respective phenol. The four compounds inhibited enzymic lipid peroxidation and showed weak peroxyl scavenging activity. They also reduced LTB 4 release from human neutrophils stimulated by A23187. The chalcone 3b was the only compound able to inhibit in a concentration-dependent way, synovial human recombinant phospholipase A 2 activity, human platelet TXB 2 generation, and human neutrophil degranulation. This chalcone exert…

Neutrino Pair Synchrotron Radiation from Relativistic Electrons in Strong Magnetic Fields

1995

The emissivity for the neutrino pair synchrotron radiation in strong magnetic fields has been calculated both analytically and numerically for high densities and moderate temperatures, as can be found in neutron stars. Under these conditions, the electrons are relativistic and degenerate. We give here our results in terms of an universal function of a single variable. For two different regimes of the electron gas we present a simplified calculation and compare our results to those of Kaminker et al. Agreement is found for the classical region, where many Landau levels contribute to the emissivity , but some differences arise in the quantum regime. One finds that the emissivity for neutrino …

Ein aus Keggin-Einheiten aufgebautes, kettenartiges Heteropolyanion: Synthese und Struktur von (ET)8n[PMnW11O39]n · 2nH2O

1995

Book Review: Stereoselective Synthesis. 2nd Edition. By M. Nógrádi

1995

Photoemission of electrons into electrolyte from cadmium oxide layers formed by anodic oxidation of undeformed and plastically deformed cadmium plates

1995

Studies of electron emission (external photoeffect) at the electrode/solution interface are an important part of contemporary photoelectrochemistry. The results of systematic studies of this phenomenon led to the formulation of fundamental relationships and to new methods for investigation of the physicochemical processes occurring at the electrode-electrolyte interface [1-4]. In particular, photoemission measurements enabled a number of parameters relating to the structure of the semiconductor/electrolyte interface to be determined. The photoemission current from semiconductors with many surface states to solutions with a sufficiently high electrolyte concentration is described by the well…

Zweitmalignome nach malignen Erkrankungen im Kindesalter

1995

Since 1980 the German Registry of Childhood Malignancies has been established. In the framework of the long-term follow-up secondary malignancies are reported continually to the registry. An additional retrospective inquiry to all treating clinicians and principal investigators of clinical trials as well as a link to a previously existing pool of secondary malignancies (1) lead to a completion of the data. At the registry now 329 patients with second malignant neoplasms have been observed. 41.3% of them had been developed the first malignancy before the registry started its work in 1980. The most common primary malignancies are acute lymphoblastic leukaemia (ALL, 28.6%), brain tumours (12.2…

The relationship between bipolar disorder and alcoholism: a controlled family study.

1995

SYNOPSISBipolar disorder and alcoholism are familial disorders. The familial–genetic relationship between both is controversial and has received insufficient study. This study explores whether bipolar disorder and alcoholism share familial risk factors, and whether the co-occurrence of lifetime diagnosis of bipolar disorder and alcoholism is familial. We report on first-degree relatives of 146 consecutively admitted patients with either bipolar disorder or/and alcoholism; relatives of the patients (in total 728 relatives directly interviewed) were compared with first-degree relatives of 109 general population probands (320 relatives directly interviewed). Overlap between the familial compon…

Primary enduring negative symptoms in schizophrenia and major depression.

1995

Abstract Primary enduring negative symptoms (PENS) were studied in 26 patients with DSM-III-R schizophrenia and in 94 patients with unipolar major depressive episodes 5 years after the index episode. PENS were assessed with the Schedule for Deficit Syndrome (SDS). Negative symptoms were also assessed with the Scale for Assessment of Negative Symptoms (SANS) and subclassified into primary and secondary according to the SDS. The frequency of PENS did not differ significantly between schizophrenics and non-schizophrenic patients. Enduring negative symptoms (regardless of whether primary or not) were more frequently observed in schizophrenia (65% according to the SDS, and 88% according to the S…

Global equatorial variability of 850 and 200 hPa zonal winds from rawinsondes between 1963 and 1989

1995

The longitude-height-time variability of 3-month averaged zonal wind anomalies at 850 and 200 hPa over the equatorial area (5{degrees}N-5{degrees}S) is analyzed using a three-dimensional dataset constructed from rawinsonde data (1963-1989). The first mode, closely related to the Southern Oscillation Index, suggests a strong vertical coupling associated with a horizontal out-of-phase pattern between the central/western Pacific and the remainder of the equatorial belt. The vertical coupling appears to be phase-locked to the annual cycle with strongest intensities found over South America and near the maritime continent early in the calendar year and over the Pacific basin and Africa during th…

Investigation of Solid-Liquid Phase Transition for Sn-54wt%In Alloy by Positron Anihilation Spectroscopy

1995

The peak coincidence counting rate F(T) was measured for Sn-54wt%In alloy at the temperature range from room temperature to 400°C. It was observed that for both heating and cooling run, F(Τ) parameter changes . in the liquid phase. These changes were related to disintegration of SnII microcrystals. From a simple trapping model the defect disintegration enthalpy, H1,, was calculated. For heating and cooling run, the value of H1 was 0.53 ± 0.03 eV and 0.67 ± 0.07 eV, respectively. For well-annealed and cold rolled samples we find only one component, equal 200 ps, in the lifetime spectrum. PACS numbers: 64.70.Dv, 61.72.Cc, 78.70.Bj.

Stellenwert der MR-Tomographie bei traumatischen Patellaluxationen

1995

PURPOSE To describe the MR imaging findings in patients with lateral patellar dislocation. MATERIAL AND METHODS The MRIs of 31 patients with patellar dislocation were evaluated retrospectively. Arthroscopic surgery was performed in 23 cases. RESULTS Hemarthrosis was found in 30/31, contusions of the lateral femoral condyle in 30/31 and of the medial patellar facet in 26/31 cases. Injury of the medial patellar retinaculum was seen in 28/31 cases. Osteochondral fractures were found in 18 patients; compared to arthroscopy there were one false-positive and 5 false-negative findings concerning loose cartilage bodies. In 7 cases, patellar dislocation was not suspected before MR imaging. CONCLUSIO…

MARIOLA: a model for calculating the response of mediterranean bush ecosystem to climatic variations

1995

Abstract The paper summarizes the bush ecosystem model developed for assessing the effects of climatic change on the behaviour of mediterranean bushes assuming that temperature, humidity and rain-fall are the basic dimensions of the niche occupied by shrub species. In this context, changes in the monthly weather pattern serve only to outline the growth conditions due to the nonlinearity of response of shrubs to climatic factors. The plant-soil-atmosphere system is described by means of ordinary non-linear differential equations for the state variables: green biomass, woody biomass, the residues of green and woody biomasses, faecal detritus of mammals on the soil, and the total organic matte…

The treatment of portal hypertension: a meta-analytic review.

1995

June-september rainfall in north-eastern Africa and atmospheric signals over the tropics: A zonal perspective

1995

The connection between rainfall in northeast Africa (Djibouti, Eritrea, Ethiopia, Kenya, Somalia, Sudan, and Uganda) and various atmospheric indicators from the tropics have been investigated for the northern summer season. Variables used include zonal wind at 700 hPa and 200 hPa, sea-level pressure, and rainfall over other tropical areas, for the period 1951–1988. Strong significant correlations are shown with the Southern Oscillation and the components of the Walker cell in the Pacific Ocean. Droughts in the Ethiopia-Uganda area are associated with El Nino events and, moreover, with above normal pressure and droughts over India. Other significant relationships exist with the African monso…

Physical activity and psychological well-being among people aged 65 to 84 years.

1995

This report deals with the findings of an epidemiological interview carried out among two representative samples (n = 800 + 800) consisting of persons born in 1904-13 and in 1914-23, and living at home in the year 1988 in the city of Jyvaskyla, central Finland. The participation rate was 80% (n = 1244). It appeared that overall involvement in physical exercise decreased with increasing age, especially among the women. About 50% of the subjects carried out regular walking exercise and 40% practised some form of home gynastics which was considered not to be very intensive. About 20% of the subjects were no more physically active than was essential for performing their daily activities. Accord…