36 research outputs found

    Density functional theory calculations of the transition states for hydrogen exchange and dehydrogenation of methane by a Brönsted zeolitic proton

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    D. functional and semiempirical (MNDO) theories are used to det. transition states and the corresponding activation barriers of hydrogen exchange and dehydrogenation of methane catalyzed by a protonated zeolite cluster model. The nonlocal d. functional activation barriers were found to be 125 and 343 kJ/mol for hydrogen exchange and dehydrogenation, resp. From the imaginary frequency of one of the transition state Eigen modes, the reaction coordinates were deduced. Addnl., from the activation barrier and vibration, rotation, and translation partition functions, reaction rate consts. have been evaluated using transition state reaction rate theory. [on SciFinder (R)

    Primeiro levantamento de mosca das frutas (Diptera: Tephritidae) e diversidade de parasitoides entre frutos de myrtaceae em todo o Estado da Bahia, Brasil

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    The objective of this study was to evaluate the diversity of fruit fly (Diptera: Tephritidae) species that use myrtaceous fruit, particularly guava, as hosts in several localities in the state of Bahia and to determine the infestation rates, pupal viability rates, and fruit fly-parasitoid associations. Sampling of myrtaceous fruit was carried out in 24 municipalities in different regions in the state of Bahia. Four fruit fly species, Anastrepha fraterculus, Anastrepha zenildae, Anastrepha sororcula, and Ceratitis capitata were obtained from the collected fruit. Three parasitoid species (Hymenoptera: Braconidae) emerged from Anastrepha larvae/pupae, Doryctobracon areolatus, Utetes anastrephae, and Asobara anastrephae. Doryctobracon areolatus emerged from A. fraterculus, A. sororcula and A. zenildae; Utetes anastrephae emerged from A. fraterculus and A. zenildae; and Asobara anastrephae emerged from A. fraterculus. Fruit fly and myrtaceous fruit associations are reported for the first time in several municipalities in the state of Bahia. A. zenildae was found infesting Syzygium malaccense for the first time in Brazil

    Iron deficiency anaemia in adolescent athletes of the Vila Olímpica Fonndation of Manaus - AM

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    Considering the dearth of information with regard to the nutritional state of young athletes, were identified the prevalence of iron deficiency anaemia and its association with nutritional indicators of adolescent athletes participating in the Sport Initiation Program of the Vila Olímpica Foundation in Manaus -AM. A sample was made up of 194 voluntary adolescent male athletes classified as beginners, who participated in several different sports. Data collected was by verification of anthropometric measures (body weight, height, and skinfold thicknesses of triceps and subscapular skinfold), hemoglobin dosage utilizing a portable hemoglobinometer, HemoCue direct calorimetric method, and socioeconomic instrument. In the diagnosis of the nutritional states, we used Height-for-age- and Body Mass Index for the age indicators, adjusted cut-off points proposed by the WHO. The results showed that 9.4 % of the adolescents suffered from malnutrition, 8.2% overweight, and 4.6 obesity. The prevalence of iron deficiency anaemia found in the samples was 41.7%, with predominance in the lowest socioeconomic class. Although the prevalence of anaemia was high, the nutritional state of the adolescents did not influence these results, considering that the majority looked healthy. In view of these findings, we suggest that effective means be taken for nutritional education to minimize and/or control iron deficiency anaemia.Considerando a escassez de informações quanto ao estado nutricional de atletas jovens, identificou-se a prevalência de anemia ferropriva e sua associação com indicadores nutricionais de atletas adolescentes participantes do Programa de Iniciação Esportiva da Fundação Vila Olímpica de Manaus-AM. A amostra foi constituída por 194 atletas adolescentes do gênero masculino, voluntários, praticantes de diferentes modalidades esportivas classificados como iniciantes. A coleta dos dados foi realizada mediante verificação de medidas antropométricas (peso corporal, estatura e espessuras das dobras cutâneas tricipital e subescapular), dosagem de hemoglobina utilizando o hemoglobinômetro portátil (Sistema Hemocue) e instrumento socioeconômico. No diagnóstico do estado nutricional foram utilizados os indicadores Estatura para a Idade (E/I) e Índice de Massa Corporal para a idade (IMC/I), assumindo pontos de corte propostos pela OMS. Os resultados mostraram que 9,4% dos adolescentes apresentaram desnutrição, 8,2% sobrepeso e 4,6% obesidade. A prevalência de anemia ferropriva encontrada na amostra foi de 41,7%, com predominância na classe socioeconômica mais baixa. Embora a prevalência de anemia tenha sido elevada, o estado nutricional dos adolescentes não influenciou sobre este resultado, considerando que a maioria dos adolescentes apresentou-se eutrófica. Diante do exposto, sugere-se a adoção de medidas efetivas de intervenção e de educação nutricional visando à minimização e/ou o controle da anemia ferropriva
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