showing 36 of ~574560 from 574555 documents
Demonstration and study of characters of foliar « compensatory growth» phenomenon in grapevine (<em>Vitis vinifera</em> L.)
1996
<p style="text-align: justify;">Defoliation and decapitation experiments showed that the growth of a grapevine leaf was inhibited by both the terminal bud and the younger higher leaves. There is a phenomenon of synergy between these two influences. A young leaf freed of these two influences showed a higher growth rate than the norm ; this is « compensatory growth ». It is when a leaf is in its phase of maximal growth that it is most able to realize this &amp;laquo compensatory growth ». This is not due to a longer growth time, but more to a faster growth rate. This « compensatory growth » is not the consequence of competition between leaf growth and internodal elongation. Exogenou…
Observation of two-XUV-photon ionization using harmonic generation from a short, intense laser pulse
1996
We report the observation of a two-photon ionization process in the XUV wavelength regime. In a near-resonant 1 + 1 ionization scheme, Ar atoms are ionized absorbing the 15 eV third harmonic photons produced in a gas jet by the 0.5 ps intense laser pulses of a KrF excimer laser emitting at 248.6 nm. The present demonstration of a non-linear process in the XUV regime reveals feasibility of high-intensity applications utilizing the uniquely high peak power of non-conventional short wavelength radiation sources based on harmonic generation.
Le"nez électronique"en quête de crédibilité
1996
National audience
Supernova Bounds on Supersymmetric $R$-parity Violating Interactions
1996
We re-examine resonant massless-neutrino conversions in a dense medium induced by flavour changing neutral current (FCNC) interactions. We show how the observed $\bar\nu_e$ energy spectra from SN1987a and the supernova $r$-process nucleosynthesis provide constraints on supersymmetric models with $R$ parity violation, which are much more stringent than those obtained from the laboratory. We also suggest that resonant massless-neutrino conversions may play a positive role in supernova shock reheating. Finally, we examine the constraints on explicit $R$-parity-violating FCNCs in the presence of non-zero neutrino masses in the eV range, as indicated by present hot dark matter observations.
Effect of formulation agents on the joint action of aclonifen and bentazon
1996
International audience
Non-equilibrium surface diffusion in the O/W(110) system
1996
In this Letter, we present results of an extensive Monte Carlo study of the O/W(110) system under non-equilibrium conditions. We study the mean square displacements and long wavelength density fluctuations of adatoms. From these quantities, we define effective and time-dependent values for the collective and tracer diffusion mobilities. These mobilities reduce to the usual diffusion constants when equilibrium is reached. We discuss our results in view of existing experimental measurements of effective diffusion barriers, and the difficulties associated with interpreting non-equilibrium data.
Female bank voles ( Clethrionomys glareolus ) prefer dominant males; but what if there is no choice?
1996
Both intra-sexual competition between males and female mate choice have been found to affect mating behaviour in rodents. We studied female choice in the bank vole (Clethrionomys glareolus) under circumstances where male-male competition was excluded and the female could interact and mate freely with the males. Mating behaviour was observed in two situations: (1) the female encountered two males with a clear dominance relationship; and (2) the two males were equal in their social status. In all tests where a female in postpartum oestrus had a choice between males of different social rank she mated with the dominant one. When choosing between an even pair of males there was no difference in …
The first excited singlet state of s‐tetrazine: A theoretical analysis of some outstanding questions
1996
The equation‐of‐motion coupled cluster method for excited electronic states (EOMEE‐CC) is applied to study the structure and selected properties of the first excited singlet state of s‐tetrazine. Adiabatic S1←S0 excitation energies obtained with large basis sets containing up to 270 functions are uniformly somewhat above the experimental 0–0 value of 2.238 eV, but nevertheless are the most accurate calculations reported to date for this quantity. The equilibrium geometry of S1 predicted in this study is in excellent agreement with another high‐level calculation, and moreover is quantitatively consistent with both the intensity of vibrational progressions observed in absorption and measured …
Viability costs of condition-dependent sexual male display in a drumming wolf spider
1996
According to the conditional handicap models females use male ornaments as honest signals of male viability. The assumptions for honest signalling are that the traits are costly and that they reflect male phenotypic condition, and hence optimal trait size is largest in the most viable males. However, experimental evidence for the costs of signalling are scarce. In this study we experimentally tested whether acoustic signalling, drumming, in a wolf spider Hygrolycosa rubrofasciata is a condition dependent, costly trait, and thus offers an honest signal of quality to females. Males of this species court females by drumming dry leaves with their abdomen. Females prefer to mate with males of hi…
Prognostic value of E-cadherin expression in 413 gastric carcinomas
1996
E-cadherin is a Ca(2+)-dependent intercellular adhesion molecule known to exert an invasion-suppressor function. In the present study, E-cadherin expression was immunohistochemically investigated in a retrospective series of 413 RO-resected gastric carcinomas using the monoclonal antibody (MAb) 5H9. Of these cases, 108 tumors revealed a preserved E-cadherin expression similar to that of normal gastric mucosa. In 95 tumors, E-cadherin expression was moderately reduced and in 86 tumors highly reduced. In 124 tumors, no or only a very weak dotted expression could be detected. There was a significant correlation between the degree of E-cadherin expression and the grade of tumor differentiation,…
Minijet and transverse energy production in the BFKL regime
1996
Minijet production in hadronic and nuclear collisions through a BFKL pomeron ladder is studied for the energies of the future LHC heavy-ion collisions. We use unintegrated gluon densities compatible with the small-$x$ increase of parton distributions observed at HERA. We show that at LHC energies the BFKL minijet and transverse energy production is at most of the same order of magnitude as that in the collinear factorization approach.
Two-Dimensional Polytypism of “Crystalline” (C5Me5)ReO3
1996
Crystals of Cp*ReO3 present a rare case of two-dimensional polytypism. They consist of a polytypic packing (in the bc plane) of ordered polar chains of three-legged piano-stool Cp*ReO3 molecules (stacked head-to-tail along the a axis). The two-dimensional polytypism arises from the possibility of building a similar motif both with 2-fold screw axes and inversion centers as packing operators, i.e. from the possibility of packing together neighboring chains of equal or different polarity.
Conformal and non-conformal symmetries in 2D dilaton gravity
1996
We introduce new extra symmetry transformations for generic 2D dilaton-gravity models. These symmetries are non-conformal but special linear combinations of them turn out to be the extra (conformal) symmetries of the CGHS model and the model with an exponential potential. We show that one of the non-conformal extra symmetries can be converted into a conformal one by means of adequate field redefinitions involving the metric and the derivatives of the dilaton. Finally, by expressing the Polyakov-Liouville effective action in terms of an auxiliary invariant metric, we construct one-loop models which maintain the extra symmetry of the classical action. © 1997 Elsevier Science B.V.
Quantum paraelectric and induced ferroelectric states in
1996
Nominally pure has been studied by dielectric spectroscopy using small (linear regime) as well as large electrical fields (non-linear regime) up to . In addition measurements of the specific heat and its field-dependent contribution have been carried out. The field dependence of the dielectric constant and the specific heat can be well described by the transverse Ising Hamiltonian including tunnelling and external field terms. It gives evidence for the existence of polar clusters at low temperatures which are supposed to be associated with the quantum paraelectric state below in accord with recent free-energy calculations. The low-field third-harmonic susceptibility which measures the polar…
Connection between certain massive and massless diagrams
1996
A useful connection between two-loop massive vacuum integrals and one-loop off-shell triangle diagrams with massless internal particles is established for arbitrary values of the space-time dimension {ital n}. {copyright} {ital 1996 The American Physical Society.}
Participation of Two Ser-Ser-Phe-Tyr Repeats in Interleukin-6 (IL-6)-Binding Sites of the Human IL-6 Receptor
1996
The alpha-subunit of interleukin-6 (IL-6) receptor is a member of the hematopoietin receptor family. The alignment of its amino acid sequence with those of other members of this family (human somatotropin receptor/murine IL-3 receptor beta and human IL-2 receptor beta) has suggested that amino acids included in two SSFY repeats found in each of its hematopoietin receptor domains, contribute to the binding of the ligand. The involvement of these amino acids in IL-6 binding and signal transduction was studied by site-directed mutagenesis and molecular modelling. We present a computer-derived three-dimensional model of the IL-6/IL-6 receptor complex based on the structure of the human somatotr…
Positron lifetime measurements on neutron‐irradiated InP crystals
1996
Neutron‐irradiated InP single crystals have been investigated by positron‐lifetime measurements. The samples were irradiated with thermal neutrons at different fluences yielding concentrations for Sn‐transmuted atoms between 2×1015 and 2×1018 cm−3. The lifetime spectra have been analyzed into one exponential decay component. The mean lifetimes show a monotonous increase with the irradiation dose from 246 to 282 ps. The increase in the lifetime has been associated to a defect containing an Indium vacancy. Thermal annealing at 550 °C reduces the lifetime until values closed to those obtained for the as‐grown and conventionally doped InP crystals. navarrof@evalvx.ific.uv.es ; Jose.Ferrero@uv.es
Nullité facultative. Préjudice subi par le débiteur ou par ses créanciers, Elément indifférent
1996
International audience; (Com. 24 oct. 1995, Banque populaire Bretagne Atlantique c/ SA Cloarec et autres ; Com. 9 janv. 1996, Banque de Bruxelles Lambert France c/ Bléry ès qual. et autre)
Compensation. Créance admise au passif et dette de restitution d'une remise en compte courant effectuée en période suspecte, Compensation (non)
1996
International audience; (Com. 24 oct. 1995, Banque populaire Bretagne Atlantique c/ SA Cloarec et autres)
Déclaration et vérification des créances. Transfert dans un plan de cession d'un nantissement de matériel, Echéances postérieures devant être payées …
1996
International audience; (Com. 20 juin 1995, Soc. Sodero c/ Di Martino ès qual. et autres)
Compensation. Réciprocité des créances comme conséquence d'une confusion des patrimoines de deux sociétés (oui), Connexité des créances dans un ensem…
1996
International audience; (Com. 9 mai 1995, Soc. Lapidor c/ CEMA et autres)
Suspension des poursuites individuelles. Demande de délivrance d'un lot sous astreinte, Action tendant à la condamnation du débiteur au paiement d'un…
1996
International audience; (Com. 28 mars 1995, Soc. France direct service et autres c/ Mme Santucci)
La validité douteuse de la clause prévoyant le prononcé de la sentence arbitrale dans un délai de trois mois après la clôture de l'instruction consta…
1996
International audience; (Dijon, 17 janv. 1994, Sté Cobra c/ Sté Saga et autres, inédit)
Suspension des poursuites individuelles. Action en exécution d'une promesse de caution, Application (oui)
1996
International audience; (Com. 6 juin 1995, Vienne et FVMC c/ Cts Guillermain)
Compensation. Créance soumise aux délais d'un plan de continuation (oui)
1996
International audience; (Com. 24 oct. 1995, Soc. Union des coopérateurs d'Alsace (UCA) c/ Soc. Gedis et autres)
Clause compromissoire. Transport maritime-clause insérée au connaissement, Acceptation par le chargeur-opposabilité au destinataire-acceptation par l…
1996
International audience; (Com. 29 nov. 1994, Navire Stolt Osprey, DMF 1995. 218, note Y. Tassel, obs. Bonnassies, DMF 1995. 200. Com. 20 juin 1995, Navire Johnny TWC, Rev. arb. 1995. 623, note J.-L. Goutal. Versailles, 14 déc. 1995, SA MSC c/ SA Gan Atican et autres, inédit)
Cautionnement. Plan de cession. Contrats cédés, Conséquences pour la caution
1996
International audience; (Com. 21 nov. 1995, Texier c/ SA Soferbail)
Compensation. Contrat et acte ponctuel détaché de toute connexité, Exclusion de la compensation
1996
International audience; (Civ. 3e, 18 juill. 1995, Malandri c/ Filippi, ès qual. et autre)
Arbitrage international. Clause compromissoire - champs d'application, Chaîne non translative de contrats - Principe de l'effectivité de la clause co…
1996
International audience; (Paris, 22 mars 1995, Sté Aquaboulevard et autres c/ Sté Statinor et autres, inédit)
Clause compromissoire. Nullité manifeste, Tribunal arbitral, Composition, Arbitres, Nombre pair, Prévision d'un tiers arbitre départiteur, Article 14…
1996
International audience; (Paris, 3 mai 1995 et 13 sept. 1995, Sté La Moirette c/ Sté LTM France, Catel et autres c/ Quilès et autres, Rev. arb. 1995. 631, note P. Level)
Doubly charged Higgs at LHC
1996
We have investigated production of doubly charged Higgs particles $\Delta_{L,R}^{++}$ via WW fusion process in proton-proton collisions at LHC energies in the framework of the left-right symmetric model. The production cross section of the right-triplet Higgs is for representative values of model parameters at femtobarn level. The discovery reach depends on the mass of the right-handed gauge boson W_R. At best $\Delta_R^{++}$ mass up to 2.4 TeV are achievable within one year run. For $\Delta^{++}_L$ the corresponding limit is 1.75 TeV which depends on the value of the left-triplet vev v_L. Comparison with Drell-Yan pair production processes shows that studies of the WW fusion processes exte…
Adaptive Control of a Gas Turbine Engine for Axial Compressor Faults
1996
An adaptive control system for a gas turbine engine which diagnoses conditions of axial compressor faults is proposed and analyzed. Nonlinear models of the gas turbine, neural networks and genetic algorithms are used in this research. The adaptive control system minimizes the reduction in gas turbine performance deriving from non-destructive faults. In the absence of faults, the system automatically performs the optimization of the engine between overhauls. Improvements concern the definition of adaptive control with faults in progress, and the real-time optimization of the engine during its operative life between overhauls. Simulation results of the suggested control system are also discus…
Assessing the operational efficiency of agricultural training systems
1996
The aim of this study was to assess the operational efficiency of agricultural training systems. Are the most highly trained farmers more efficient than those with less training ? This analysis focuses on the effects of training at two particular stages : when setting up a farm and deciding how it should be run, and during the initial stages, how efficiently the business is run. The findings show that the agricultural training systems should make greater efforts to accompany young farmers setting up in business, by helping them to define their farming objectives more clearly. Accumulating manpower does not suffice : in order tu succeed, the optimum conditions of production have to be achiev…
Search for νμ(νe) ↔ ντ oscillations with a detector based on a emulsion-silicon target
1996
We discuss the performance of a next generation νμ(νe)↔ ντ oscillation experiment, based on a target consisting of a sandwich of nuclear emulsion layers and silicon detectors. The target would be followed by a full spectrometer for energy-momentum measurement and particle identification. A τ-enriched sample is selected in terms of vertex and kinematical criteria using the electronic spectrometer, with very high efficiency, while at the same time reducing the load of background events to be scanned by up to two orders of magnitude. Events fulfilling the selection criteria are very efficiently located and scanned in the emulsion, thanks to the very good resolution allowed by the silicon track…
New Signatures for a Light Stop at LEP2 in SUSY Models with Spontaneously Broken R-Parity
1996
In a class of supersymmetric models with R-parity breaking the lightest stop can have new decay modes into third generation fermions, $\tilde{t}_1 \rightarrow b + \tau$. We show that this decay may be dominant or at least comparable to the ordinary R-parity conserving mode $\tilde{t}_1 \rightarrow c + \tilde{\chi}_1^0$, where $\tilde{\chi}_1^0$ denotes the lightest neutralino. The new R-parity violating decay mode could provide new signatures for stop production at LEP.
Dynamics of thermally induced optical nonlinearity in GaSe thin slabs
1996
A study of the nonlinear effects shown by thin slabs of GaSe metaled with Au is presented.