7 research outputs found

    Differential cross-section measurements of the production of four charged leptons in association with two jets using the ATLAS detector

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    Differential cross-sections are measured for the production of four charged leptons in association with two jets. These measurements are sensitive to final states in which the jets are produced via the strong interaction as well as to the purely-electroweak vector boson scattering process. The analysis is performed using proton-proton collision data collected by ATLAS at √s = 13 TeV and with an integrated luminosity of 140 fb−1. The data are corrected for the effects of detector inefficiency and resolution and are compared to state-of-the-art Monte Carlo event generator predictions. The differential cross-sections are used to search for anomalous weak-boson self-interactions that are induced by dimension-six and dimension-eight operators in Standard Model effective field theory

    Floral Assemblages and Patterns of Insect Herbivory during the Permian to Triassic of Northeastern Italy

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    To discern the effect of the end-Permian (P-Tr) ecological crisis on land, interactions between plants and their insect herbivores were examined for four time intervals containing ten major floras from the Dolomites of northeastern Italy during a Permian-Triassic interval. These floras are: (i) the Kungurian Tregiovo Flora;(ii) the Wuchiapingian Bletterbach Flora;(iii) three Anisian floras;and (iv) five Ladinian floras. Derived plant-insect interactional data is based on 4242 plant specimens (1995 Permian, 2247 Triassic) allocated to 86 fossil taxa (32 Permian, 56 Triassic), representing lycophytes, sphenophytes, pteridophytes, pterido-sperms, ginkgophytes, cycadophytes and coniferophytes from 37 million-year interval (23 m. yr. Permian, 14 m. yr. Triassic). Major Kungurian herbivorized plants were unaffiliated taxa and pteridosperms;later during the Wuchiapingian cycadophytes were predominantly consumed. For the Anisian, pteridosperms and cycadophytes were preferentially consumed, and subordinately pteridophytes, lycophytes and conifers. Ladinian herbivores overwhelming targeted pteridosperms and subordinately cycadophytes and conifers. Throughout the interval the percentage of insect-damaged leaves in bulk floras, as a proportion of total leaves examined, varied from 3.6% for the Kungurian (N = 464 leaves), 1.95% for the Wuchiapingian (N = 1531), 11.65% for the pooled Anisian (N = 1324), to 10.72% for the pooled Ladinian (N = 923), documenting an overall herbivory rise. The percentage of generalized consumption, equivalent to external foliage feeding, consistently exceeded the level of specialized consumption from internal feeding. Generalized damage ranged from 73.6% (Kungurian) of all feeding damage, to 79% (Wuchiapingian), 65.5% (pooled Anisian) and 73.2% (pooled Ladinian). Generalized-to-specialized ratios show minimal change through the interval, although herbivore component community structure (herbivore species feeding on a single plant-host species) increasingly was partitioned from Wuchiapingian to Ladinian. The Paleozoic plant with the richest herbivore component community, the coniferophyte Pseudovoltzia liebeana, harbored four damage types (DTs), whereas its Triassic parallel, the pteridosperm Scytophyllum bergeri housed 11 DTs, almost four times that of P. liebeana. Although generalized DTs of P. liebeana were similar to S. bergeri, there was expansion of Triassic specialized feeding types, including leaf mining. Permian-Triassic generalized herbivory remained relatively constant, but specialized herbivores more finely partitioned plant- host tissues via new feeding modes, especially in the Anisian. Insect-damaged leaf percentages for Dolomites Kungurian and Wuchiapingian floras were similar to those of lower Permian, north-central Texas, but only one-third that of southeastern Brazil. Global herbivore patterns for Early Triassic plant-insect interactions remain unknown

    Efeitos do trabalho sobre a saúde de adolescentes Effects of work on the health of adolescents

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    O estudo analisa conseqüências do trabalho para as condições de vida, saúde e desenvolvimento psicossocial de adolescentes. Participaram do estudo 354 estudantes de 14 a 18 anos, do ensino médio, período noturno. A análise das representações foi realizada a partir da coleta de evocações livres. Os dados sobre sono foram obtidos por meio de questionários, sobre auto-percepções acerca das condições de vida e trabalho, sintomas de saúde e doenças. A análise de dados foi realizada com o software EVOC 2000 e SPSS. Constataram-se diferenças significativas na duração média de sono entre os adolescentes: os trabalhadores relataram menores médias de duração de sono. Entre os trabalhadores, referiram dormir menos os que sentem sono no trabalho e nas aulas, têm maiores exigências psicológicas no trabalho, ganham acima de 1 salário mínimo mensal, jornadas acima de 6 horas diárias ou acima de 20 horas semanais, trabalham em local barulhento e com presença de gases e vapores. As representações do trabalho entre os jovens apontam contradição entre o seu reconhecimento como valor moral positivo para o desenvolvimento psicossocial e a construção da identidade, e as conseqüências negativas decorrentes da exposição a cargas físicas e psicológicas precocemente.<br>This study evaluated life and work conditions and their impact on the health and psychological development of adolescents. A number of 354 high school students, 14 to 18 years old, studying during evening period took part in this study. Data were collected using free evocation technique and questionnaires. Data on sleep during the weekdays were obtained using questionnaires, filled out by students regarding life and work conditions, health symptoms and illness. Data were analyzed with software EVOC 2000 for the social representations, and T-Student, ANOVA, Mann-Whitney e Kruskal-Wallis tests were employed for analyze health and sleep conditions. Differences were found among worker students who reported shorter mean sleep durations and: males, feeling sleepy at work and classes, referring to tougher psychological demands at work, working as salesperson, earning more than 1 minimum monthly wage, working more than 6 hours per day or 20 hours per week, working in noisy environment or polluted with gases and vapors. The representation of work among teen workers point a contradiction between recognizing work as a moral positive value to psychosocial development and identity construction, and the negative consequences due to precocious exposure to physical and psychological workloads
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