Charm and beauty structure of the proton

This paper will review the data collected by the H1 and ZEUS Collaborations concerning the production of heavy quarks (charm and beauty) at the electron-proton collider HERA. Heavy quark production is an important testing ground for quantum chromodynamics (QCD), because QCD calculations are expected to be reliable if a hard scale is present in the process. In heavy quarks production a hard scale is provided by the quark mass. Moreover heavy quarks production can give direct access to the gluon density in the proton due to the fact that it proceeds, in QCD, almost exclusively via photon-gluon fusion, where a photon from the incoming electron interacts with a gluon in the proton giving an heavy quark-anti-quark pair. Results will be shown both for deep-inelastic scattering (DIS), where the virtuality of the exchanged boson Q**2 is large, and photo-production, where the Q**2 is equal to zero. Various experimental techniques are used in order to select charm and beauty events, ranging from the measurement of D* cross section to impact parameter analyses. The results are found to be compatible with the predictions of perturbative QCD. A brief summary of the open charm analyses done by the COMPASS Collaboration will be also given.Comment: 20 pages; Talk presented at ``Heavy Quarks & Leptons'', October 16th -- 20th 2006, Munich, German

Os estágios imaturos de Asopinae e taxonomia de Tynacantha Dallas, Tylospilus Stål e Podisus Herrich-Schäffer (Hemiptera: Pentatomidae)

Os percevejos (Heteroptera) compõem o grupo mais diverso de insetos hemimetábolos, reunindo linhagens com diferentes hábitos alimentares, dentro eles, fitófagos, micófagos, hematófagos e predadores. A maioria dos populares percevejos fede-fede (Pentatomoidea) é fitófaga, mas a subfamília Asopinae (Pentatomidae) se destaca por conta do hábito predador zoofitófago, se alimentando principalmente de outros insetos, mas incluindo também recursos vegetais na dieta. O grupo apresenta cerca de 300 espécies descritas, no entanto, a maioria carece de informações taxonômicas e biológicas básicas. Esta tese tem como objetivos investigar os hábitos de vida e a morfologia dos estágios imaturos de Asopinae, e solucionar problemas taxonômicos nos gêneros Tynacantha Dallas, Tylospilus Stål e Podisus Herrich-Schäffer. A descrição do ciclo de vida e da morfologia dos ovos e ninfas de sete espécies (Oplomus catena (Drury), Alcaeorrhynchus grandis (Dallas), Brontocoris tabidus (Signoret), Marmessulus brasilianus Schouteden, Podisus fuscescens (Dallas), Podisus nigrispinus (Dallas), e Supputius cincticeps (Stål)) é apresentada. A partir de técnicas de microscopia eletrônica de varredura, características relevantes em ambos os estágios de vida foram estudadas, dentre elas, os processos aeromicropilares e a superfície do cório dos ovos, o lábio, e o sistema odorífero das ninfas. Dentre os resultados obtidos, destaca-se a variabilidade morfológica e interespecífica observada em ambos os estágios. Esta diversidade permite a identificação em nível de espécie ou de gênero na maioria dos casos e, portanto, pode ser aplicada na taxonomia e sistemática dos asopíneos. Revisitando o histórico taxônomico, consultando espécimes-tipo, e examinando exemplares de diferentes coleções, se procedeu a revisão taxonômica com descrição de duas novas espécies de Tynacantha, a redescrição de Tylospilus nigrobinotatus (Berg) e descrição de Tylospilus armatussimilis Brugnera, Paim & Grazia, e atualizações taxônomicas em Podisus, incluindo a descrição de cinco novas espécies. Nestes trabalhos, são fornecidas imagens dos exemplares e de estruturas importantes para a identificação, novas descrições, chaves de identificação, e mapas de distribuição. A importância de examinar exemplares-tipo para a tomada de decisões taxonômicas em Asopinae é destacada, e problemáticas taxonômicas que envolvem os gêneros estudados são discutidas.The true bugs (Heteroptera) compose the most diverse group of hemimetabolous insects, containing lineages with different alimentary habits, such as phytophagous, mycetophagous, hematophagous, and predators. The majority of stink bugs (Pentatomoidea) are phytophagous, however, the members of Asopinae (Pentatomidae) are zoophytophagous, feeding mainly on other insects, but also including plants in the diet. The group has about 300 species described, in which most lack basic taxonomic and biological information. This thesis aims to investigate the natural history and morphology of the immature stages of Asopinae, and to solve taxonomic problems in the genera Tynacantha Dallas, Tylospilus Stål and Podisus Herrich-Schäffer. The description of the life cycle and morphology of eggs and nymphs of six species (Oplomus catena (Drury), Alcaeorrhynchus grandis (Dallas), Brontocoris tabidus (Signoret), Marmessulus brasilianus Schouteden, Podisus fuscescens (Dallas), Podisus nigrispinus (Dallas), and Supputius cincticeps (Stål)) is presented. Using scanning electron microscopy technics, relevant features in the eggs and nymphs were studied, such as the aeromicropilary processes and chorion of the eggs, and the labium, and odoriferous system of nymphs. The obtained results highlights the morphological variability observed in both stages. This diversity allows the identification of the specie or genus in most cases, thus, should be explored in the taxonomy and systematics of the asopines. By revisiting the taxonomic history, and consulting type and pinned specimens of different collections, are presented: the taxonomic revision and description of two new species of Tynacantha; the redescription of Tylospilus nigrobinotatus (Berg) and description of Tylospilus armatussimilis Brugnera, Paim & Grazia; the correction of taxonomic problems in Podisus, including the description of five new species. Photographies, new descriptions, identification keys, and maps of distribution are provided. The importance of examining type specimens of Asopinae is highlighted, and the major taxonomic problems involving the studied genera are discussed

Controlling electron-electron correlation in frustrated double ionization of molecules with orthogonally polarized two-color laser fields

We demonstrate the control of electron-electron correlation in frustrated double ionization (FDI) of the two-electron triatomic molecule D$_{3}^{+}$ when driven by two orthogonally polarized two-color laser fields. We employ a three-dimensional semi-classical model that fully accounts for the electron and nuclear motion in strong fields. We analyze the FDI probability and the distribution of the momentum of the escaping electron along the polarization direction of the longer wavelength and more intense laser field. These observables when considered in conjunction bear clear signatures of the prevalence or absence of electron-electron correlation in FDI, depending on the time-delay between the two laser pulses. We find that D$_{3}^{+}$ is a better candidate compared to H$_{2}$ for demonstrating also experimentally that electron-electron correlation indeed underlies FDI.Comment: 5 pages, 4 figure

The OPERA magnetic spectrometer

The OPERA neutrino oscillation experiment foresees the construction of two magnetized iron spectrometers located after the lead-nuclear emulsion targets. The magnet is made up of two vertical walls of rectangular cross section connected by return yokes. The particle trajectories are measured by high precision drift tubes located before and after the arms of the magnet. Moreover, the magnet steel is instrumented with Resistive Plate Chambers that ease pattern recognition and allow a calorimetric measurement of the hadronic showers. In this paper we review the construction of the spectrometers. In particular, we describe the results obtained from the magnet and RPC prototypes and the installation of the final apparatus at the Gran Sasso laboratories. We discuss the mechanical and magnetic properties of the steel and the techniques employed to calibrate the field in the bulk of the magnet. Moreover, results of the tests and issues concerning the mass production of the Resistive Plate Chambers are reported. Finally, the expected physics performance of the detector is described; estimates rely on numerical simulations and the outcome of the tests described above.Comment: 6 pages, 10 figures, presented at the 2003 IEEE-NSS conference, Portland, OR, USA, October 20-24, 200

Prevalence of Chlamydia abortus in Belgian ruminants

Chlamydia (C.) abortus enzootic abortion still remains the most common cause of reproductive failure in sheep-breeding countries all over the world. Chlamydia abortus in cattle is predominantly associated with genital tract disease and mastitis. In this study, Belgian sheep (n=958), goats (n=48) and cattle (n=1849) were examined, using the ID Screen (TM) Chlamydia abortus indirect multi-species antibody ELISA. In the sheep, the highest prevalence rate was found in Limburg (4.05%). The animals of Antwerp, Brabant and Liege tested negative. The prevalence in the remaining five regions was low (0.24% to 2.74%). Of the nine goat herds, only one herd in Luxembourg was seropositive. In cattle, the highest prevalence rate was found in Walloon Brabant (4.23%). The animals of Limburg and Namur tested negative. The prevalence rate in the remaining seven regions ranged between 0.39% and 4.02%

Status of the GERDA experiment

The study of neutrinoless double beta (0nbb) decay is the only one presently known approach to the fundamental question if the neutrino is a Majorana particle, i.e. its own anti-particle. The observation of 0nbb decay would prove that lepton number is not conserved, establish that neutrino has a Majorana component and, assuming that light neutrino is the dominating process, provide a method for the determination of its effective mass. GERDA is a new 0nbb decay experiment which is currently taking data at the Laboratori Nazionali del Gran Sasso (LNGS) of INFN in Italy. It implements a new shielding concept by operating bare diodes made from Ge with enriched 76Ge in high purity liquid argon supplemented by a water shield. The aim of GERDA is to verify or refute the recent claim of discovery, and, in a second phase, to achieve a two orders of magnitude lower background index than past experiments, to increase the sensitive mass and to collect an exposure of 100 kg yr. The paper will discuss design, physics reach, and status of data taking of GERDA.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard

Lianas in silico, ecological insights from a model of structural parasitism

Tropical forests are a critical component of the Earth system, storing half of the global forest carbon stocks and accounting for a third of terrestrial photosynthesis. Lianas are structural parasites that can substantially reduce the carbon sequestration capacity of these forests. Simulations of this peculiar growth form have only recently started and a single vegetation model included lianas so far. In this work we present a new liana implementation within the individual based model Formind. Initial tests indicate high structural realism both horizontal and vertical. In particular, we benchmarked the model against empirical observations of size distribution, mean liana cluster size and vertical leaf distribution for the Paracou site in French Guiana. Our model predicted a reduction of above-ground biomass between 10% for mature stands to 45% for secondary plots upon inclusion of lianas in the simulations. The reduced biomass was the result of a lower productivity due to a combination of lower tree photosynthesis and high liana respiration. We evaluated structural metrics (LAI, basal area, mean tree-height) and carbon fluxes (GPP, respiration) by comparing simulations with and without lianas. At the equilibrium, liana productivity was 1.9tC ha y or 23% of the total GPP and the forest carbon stocks were between 5% and 11% lower in simulations with lianas. We also highlight the main strengths and limitations of this new approach and propose new field measurements to further the understanding of liana ecology in a modelling framework

Full-dimensional treatment of short-time vibronic dynamics in molecular high-harmonics generation process in methane

We present derivation and implementation of the Multi-Configurational Strong-Field Approximation with Gaussian nuclear Wave Packets (MC-SFA-GWP) -- a version of the molecular strong-field approximation which treats all electronic and nuclear degrees of freedom, including their correlations, quantum-mechanically. The technique allows, for the first time, realistic simulation of high-harmonic emission in polyatomic molecules without invoking reduced-dimensionality models for the nuclear motion or the electronic structure. We use MC-SFA-GWP to model isotope effects in high-harmonics generation (HHG) spectroscopy of methane. The HHG emission in this molecule transiently involves strongly vibronically-coupled $^2F_2$ electronic state of the $\rm CH_4^+$ cation. We show that the isotopic HHG ratio in methane contains signatures of: a) field-free vibronic dynamics at the conical intersection (CI); b) resonant features in the recombination cross-sections; c) laser-driven bound-state dynamics; as well as d) the well-known short-time Gaussian decay of the emission. We assign the intrinsic vibronic feature (a) to a relatively long-lived ($\ge4$ fs) vibronic wave packet of the singly-excited $\nu_4$ ($t_2$) and $\nu_2$ ($e$) vibrational modes, strongly coupled to the components of the $^2F_2$ electronic state. We demonstrate that these physical effects differ in their dependence on the wavelength, intensity, and duration of the driving pulse, allowing them to be disentangled. We thus show that HHG spectroscopy provides a versatile tool for exploring both conical intersections and resonant features in photorecombination matrix elements in the regime not easily accessible with other techniques

Ruptures and repairs of group therapy alliance. an untold story in psychotherapy research

Although previous studies investigated the characteristics of therapeutic alliance in group treatments, there is still a dearth of research on group alliance ruptures and repairs. The model by Safran and Muran was originally developed to address therapeutic alliance in individual therapies, and the usefulness of this approach to group intervention needs to be demonstrated. Alliance ruptures are possible at member to therapist, member to member, member to group levels. Moreover, repairs of ruptures in group are quite complex, i.e., because other group members have to process the rupture even if not directly involved. The aim of the current study is to review the empirical research on group alliance, and to examine whether the rupture repair model can be a suitable framework for clinical understanding and research of the complexity of therapeutic alliance in group treatments. We provide clinical vignettes and commentary to illustrate theoretical and research aspects of therapeutic alliance rupture and repair in groups. Our colleague Jeremy Safran made a substantial contribution to research on therapeutic alliance, and the current paper illustrates the enduring legacy of this work and its potential application to the group therapy context