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The tightly integrated, cooperative nature of social insect colonies can be threatened by kin-selected conflicts among colony mates. Some conflicts are known to occur when classes of relatives can be distinguished by obvious cues such as sex. However, less is known about the more pervasive and potentially destructive conflicts that would arise if individuals could generally recognize and preferentially aid their closest kin within a colony. To study natural discrimination in colonies with many patrilines or matriUnes, where it should be most profitable to individuals, requires good molecular markers. We used microsatellite genotyping to show that a highly polygynous social wasp does not exercise within-colony discrimination in the context of colony fissioning.

Inclusive production of ϕ,K*0, and\(\overline {K*^0 } \) mesons has been measured in γp, π±p andK± p collisions at beam energies of 65 GeV

The inclusive production of ρ0 mesons was measured in γp andh ± p collisions at beam energies of 65 GeV≦E γ≦175 GeV andE h =80, 140 GeV, respectively, whereh is π orK. Cross sections were determined for all beams and energies as functions ofx F (−0.1≦x F≦1.0),p T (0≦p T≦3.5 GeV/c) and the polar decay angle of the ρ0 by fitting the ρ0 signal in π+π- mass distributions. The ρ0 line shape is found to be distorted from a pure Breit-Wigner distribution throughout most of thex F−p T plane for both photon and hadron beams and a simple explanation is suggested. Throughout the paper emphasis is put on the comparison of photon and hadron beam data. The comparison of cross sections of γp andhp data provides a measure of the Vector Meson Dominance factor throughout thex F−p T range of the ρ0. The ρ0 production at lowp T can be described for both photon and hadron beams by a triple regge model at largex F. Similarly central production is well described by the quark-antiquark fusion model. At largep T there is an excess of ρ0 photoproduction which is consistent with the expected onset of pointlike photon interactions.

Measurements are reported of inclusive production of π0-mesons in the beam fragmentation region in γp, πp andKp collisions. Results include the ratio of π0 production inKp and πp collisions, showing reduced production from fragmentation of theK-meson, and the ratio of π0 production in photon and hadron collisions which shows agreement with modified Vector Meson Dominance at lowPT, and departures at higherPT signalling the onset of direct photon reactions. The pattern of departure from Feynman scaling at highPT points to a contribution of hard parton-parton collisions in both γp and πp collisions.

Photo- and hadroproduction data in the beam energy range 65–175 GeV have been studied with a view to isolating higher-twist processes in photoproduction from other point-like and hadron-like contributions. With selection of charged tracks havingp T >2 GeV/c and 0.28

The charged particle asymmetry, (n+−n−)/(n++n−), in inclusive photoproduction of charged particles on protons has been studied as a function ofxF andpT in the rangesxF>0 and 0

Energy-flow distributions for charged hadrons from interactions of photons, pions and kaons on hydrogen are presented as functions of ΣpT2 in the event plane. Data cover the range 0.0

Proton-induced associated strangeness production of bound hypernuclei is accompanied by large momentum transfers. Therefore, the hyperon sticking probability is low and strongly depends on short range correlations. The most favourite reactions D(p,K+)Λ3H, 3He(p,K+)Λ4He and 4He(p,K+)Λ5He were studied at LNS Saclay using the high resolution spectrometer SPES4 at ϑlab ≈ 7°. Background pions and protons were eliminated by aerogel veto-counters and several TOF cuts, respectively. The tracking of remaining kaon-like events through four horizontally and two vertically resolving drift chambers showed no evidence for respective g.s. transitions above background. Upper limits of the order of nb/sr (CMS) are deduced.

The study of light hyper‐nuclei via associated strangeness production in (p, K+) reactions is discussed. Though the process is characterized by a very large momentum transfer the presence of short range correlations is expected to rise the cross section up to the order of nb/sr. Two approved proposals for high resolution studies of this reaction are discussed and respective detection limits are presented. The first is scheduled for October 1990 at the SPES4 spectrometer at the SATURNE acclerator (LNS Saclay). The second deals with the planned upgrading of the BIG KARL magnetic spectrograph at the cooled beam facility COSY being bulit at Forschungsanlage Julich.

Single charged-particle inclusive cross sections for photon, pion and kaon beams on hydrogen at the CERN-SPS are presented as functions ofp T andx F . Data cover the range 0.01.6 GeV/c for the photon-induced data. Using the hadron-induced data to estimate the hadronic behaviour of the photon, the difference distributions and ratios of cross sections are a measure of the contribution of the point-like photon interactions. The data are compared with QCD calculations and show broadly similar features.

Measurements are reported of inclusivef 2(1270) andf 0(975) production in γp, π± p andK ± p collisions at photon beam energies of 65 to 175 GeV and hadron beam energies of 80 and 140 GeV. Thef 2 andf 0 mesons were found at masses of 1.250 GeV and 0.961 GeV respectively. Inclusivef 2 production at lowx F was found to have a similarp T dependence for each beam type, whereas an additional pion-exchange contribution was found for production by pions at highx F. Cross sections are compared with those for ρ0 production and give no indication of a non-q $$\bar q$$ component in eitherf-meson state.

Dans cet article, nous proposons d’examiner des phenomenes d’heterogeneite discursive dans deux essais philosophiques de Gilles Deleuze et Felix Guattari. Ces deux textes permettent en effet d’observer des recours extremement varies au lexique comme a la phraseologie du discours politique. Nous montrons qu’il est necessaire, pour rendre compte de la variete de ces « emprunts » et de leur fonctionnement dans le discours d’accueil, de mettre au premier plan le fait de la pluralite des discours et l’existence de « contacts » entre discours, au-dela du plan de l’enonciation et de la question de l’enchâssement des enonces. La notion de contact entre discours permet de rendre compte de l’importance des phenomenes d’emprunts entre discours, de l’existence de relations privilegiees entre certains discours (les discours ne sont pas egalement influents ou influences), comme enfin de l’existence d’une « image » stereotypique sous l’apparence de laquelle un discours apparait dans un autre. Nous mettons ensuite a l’epreuve ces propositions theoriques sur le corpus mentionne. Les phenomenes analyses relevent de trois types d’emprunts : lexicaux, phraseologiques, ou actantiels. Ces trois types d’emprunt se distinguent par la nature des marques qui permettent de les identifier comme par leur degre d’integration dans le discours d’accueil : si la place prise dans le texte par un lexique d’origine politique est aisement reperable, ainsi, dans une moindre mesure, que les phraseologies politiques et notamment la forme du slogan, ce n’est plus le cas avec la construction d’un actant collectif exhibant un ethos caracteristique du politique.

C’est aux Etats-Unis, dans les annees 1950, qu’apparait le tournant automatique de la mathematisation du langage, que nous appelons seconde mathematisation. Celle-ci se constitue a partir de la premiere mathematisation des annees 1930-40, fondee sur la logique-mathematique et la philosophie analytique, et dans les centres de traduction automatique. La traduction automatique est issue de la culture des sciences de la guerre, caracterisee par l’interaction entre sciences et ingenierie, l’omnipresence de l’etat et l’ideologie de l’automatisation. C’est donc la configuration formee par la theorie de l’information, la logique, les statistiques, le calcul numerique et la cryptographie qui va servir d’horizon de retrospection aux debuts de la TA. Concue comme technologie de guerre, celle-ci va obeir a des objectifs strategiques de production de traductions en serie et se constituer en-dehors de la linguistique. La TA et la premiere mathematisation vont constituer le socle des premiers analyseurs syntaxiques et du domaine de la « computational linguistics » a l’interface entre langages formels, syntaxe et programmation. Cet article se propose d’examiner, a partir d’une etude historique et comparative des institutions, les modes de reception de l’automatisation-mathematisation de la linguistique en France. Celle-ci est externe a plusieurs titres : les Francais ne partagent pas l’ancrage de la premiere mathematisation ; leur retard en informatique les fait entrer dans le domaine tardivement, une fois celui-ci constitue ; en consequence, la traduction automatique et la « computational linguistics » vont etre assimilees et commencer simultanement. Le contexte d’apparition de l’automatisation-mathematisation a des specificites : le nouvel horizon de retrospection comporte aussi bien des modeles elabores par des Sovietiques que par des Americains. Il existe une autre tradition de mathematisation en France, fondee sur les statistiques de vocabulaire, qui, revivifiee par la theorie de l’information va entrer en concurrence avec les modeles formels. Les linguistes francais ne s’investissent pas dans le nouveau domaine comme acteurs, mais comme evaluateurs. La reception de la seconde mathematisation va donc emprunter des operateurs de passage specifiques. Meme si le CNRS, dont la capacite de recherche s’est trouvee renforcee a la fin des annees 1950, va constituer un lieu privilegie pour l’instauration de la seconde mathematisation, des instances intermediaires seront necessaires : institutions et acteurs, societes savantes, entremetteurs, et scientifiques-passeurs dont le role va etre capital.