184 research outputs found

    Measurement of residual nucleus cross sections and recoil energies in p + Fe collisions at 300, 500, 750, 1000 and 1500 MeV

    Get PDF
    The production of residual nuclei in p + Fe collisions has been measured at GSI on the FRS facility by means of the reverse kinematic techniques at 300, 500, 750, 1000 and 1500 MeV/A. The cross-sections larger than 0.01 mb of all isotopes with Z larger than 8 have been obtained. Velocity distributions were also measured. Comparisons to models describing spallation reactions and some empirical formulae often used in astrophysics are presented. These data are directly used to calculate impurety production and DPAs in a thin window as foreseen in spallation sources or accelerator-driven systems

    Yeasts and wine off-flavours: a technological perspective

    Get PDF
    Review article. Part of the special issue "Wine microbiology and safety: from the vineyard to the bottle (Microsafety Wine)", 19-20 Nov. 2009, ItalyIn wine production, yeasts have both beneficial and detrimental activities. Saccharomyces cerevisiae is the yeast mainly responsible for turning grape juice into wine but this species and several others may also show undesirable effects in wines. Among such effects, technologists are particularly concerned with the production of offflavours that may occur during all stages of winemaking. Typical spoiling activities include the production of ethyl acetate by apiculate yeasts before fermentation, hydrogen sulphide by S. cerevisiae during fermentation phases, acetaldehyde by film-forming yeasts during bulk storage, and volatile phenols by Dekkera bruxellensis during storage or after bottling. The occurrence of these hazards depends on the technological operations designed to obtain a given type of wine and most can be avoided by current preventive or curative measures. On the contrary, good manufacturing practices must be strengthened to deal with the problem of volatile phenol production in red wines. Appropriate monitoring of D. bruxellensis populations and quantification of 4-ethylphenol is advised during storage, particularly when oak barrels are used, and absence of viable cells must be guaranteed in bottled wines. This work, which is based on our experience at winery level, aims to provide information on appropriate technological strategies to deal with the problem of off-flavours produced by yeasts

    Predicting Transitions in Low and High Levels of Risk Behavior from Early to Middle Adolescence: The TRAILS Study

    Get PDF
    The present study examined the joint development of substance use and externalizing problems in early and middle adolescence. First, it was tested whether the relevant groups found in previous studies i.e., those with an early onset, a late onset, and no onset or low levels of risk behavior could be identified, while using a developmental model of a single, underlying construct of risk behavior. Second, departing from Moffitt’s taxonomy of antisocial behavior, it was tested if early, but not late, onset risk behavior is predicted by a problematic risk profile in childhood. Data were used from TRAILS, a population based cohort study, starting at age 11 with two follow-ups at mean ages of 13.6 and 16.3 years. Latent transition analyses demonstrated that, both in early and middle adolescence, a single underlying construct of risk behavior, consisting of two classes (labeled as low and high risk behavior), adequately represented the data. Respondents could be clearly classified into four possible transition patterns from early to middle adolescence, with a transition from high to low being almost non-existent (2.5 %), low to low (39.4 %) and low to high (41.8 %) being the most prevalent, and high to high (16.2 %) substantial. As hypothesized, only the high-high group was characterized by a clear adverse predictor profile in late childhood, while the low-high group was not. This study demonstrates that the development of substance use is correlated with externalizing problems and underscores the theory that etiologies of early and later onset risk behavior are different

    Diversity of Meiofauna from the 9°50′N East Pacific Rise across a Gradient of Hydrothermal Fluid Emissions

    Get PDF
    Background: We studied the meiofauna community at deep-sea hydrothermal vents along a gradient of vent fluid emissions in the axial summit trought (AST) of the East Pacific Rise 9 degrees 50'N region. The gradient ranged from extreme high temperatures, high sulfide concentrations, and low pH at sulfide chimneys to ambient deep-sea water conditions on bare basalt. We explore meiofauna diversity and abundance, and discuss its possible underlying ecological and evolutionary processes. Methodology/Principal Findings: After sampling in five physico-chemically different habitats, the meiofauna was sorted, counted and classified. Abundances were low at all sites. A total of 52 species were identified at vent habitats. The vent community was dominated by hard substrate generalists that also lived on bare basalt at ambient deep-sea temperature in the axial summit trough (AST generalists). Some vent species were restricted to a specific vent habitat (vent specialists), but others occurred over a wide range of physico-chemical conditions (vent generalists). Additionally, 35 species were only found on cold bare basalt (basalt specialists). At vent sites, species richness and diversity clearly increased with decreasing influence of vent fluid emissions from extreme flow sulfide chimney (no fauna), high flow pompei worm (S: 4-7, H-loge': 0.11-0.45), vigorous flow tubeworm (S: 8-23; H-loge': 0.44-2.00) to low flow mussel habitats (S: 28-31; H-loge': 2.34-2.60). Conclusions/Significance: Our data suggest that with increasing temperature and toxic hydrogen sulfide concentrations and increasing amplitude of variation of these factors, fewer species are able to cope with these extreme conditions. This results in less diverse communities in more extreme habitats. The finding of many species being present at sites with and without vent fluid emissions points to a non endemic deep-sea hydrothermal vent meiofaunal community. This is in contrast to a mostly endemic macrofauna but similar to what is known for meiofauna from shallow-water vents

    Masculinidades e práticas de saúde na região metropolitana de Belo Horizonte - MG

    Get PDF
    O objetivo desta investigação foi identificar e analisar as representações sociais de saúde e de doença e as práticas de saúde masculina junto a homens residentes na Região Metropolitana de Belo Horizonte-MG. Foram entrevistados 100 sujeitos com idade entre 45 e 55 anos. Os dados foram submetidos às análises de evocação e de conteúdo. RESULTADOS: elementos centrais da Representação Social (RS) de saúde: "bem-estar", "cuidado" e "importante". Elementos periféricos próximos: "alegria/felicidade" e "alimentação". Elementos centrais da RS de doença: "tristeza" e "dor". Elementos periféricos próximos: "sofrimento" e "morte". Definição de "cuidar da saúde": "cuidar da alimentação" (17,25% das respostas) e "praticar atividades físicas" (11,11%). Dos sujeitos, 52% afirmaram que cuidam da própria saúde e 34% que o fazem "às vezes". Quem contribui para o cuidado com a própria saúde: "eu mesmo" (29,63%), "esposa" (25,93%). Busca por atendimento médico: "às vezes" no Hospital (69% dos sujeitos; motivo principal: "dor forte/persistente", 13,87% das respostas) ou nos consultórios (72% dos sujeitos; motivo principal: "exames de rotina", 22,22% das respostas). A análise dos resultados indica a percepção mais geral do cuidar da saúde como um conjunto de práticas individuais objetivando o "bem-estar". Os resultados também indicam considerável quantidade de ações objetivando os cuidados com a saúde, o que contraria parte das percepções tradicionais quanto à fraca associação entre masculinidades e cuidado de si
    corecore