Uma das preocupações nos estudos de adesão recai na investigação dos motivos que justificam a permanência dos praticantes em programas de exercícios físicos. Neste sentido, o objetivo da presente investigação foi identificar os grupos (categorias) de motivos que influenciam a permanência de adolescentes, adultos e idosos nos programas de exercícios físicos oferecidos nos Centros de Atividades do Serviço Social do Comércio do Distrito Federal do Brasil. Uma amostra representativa e aleatória de 986 indivíduos de ambos os sexos (15-89 anos) respondeu a um instrumento de coleta de dados para investigar aspectos sócio-demográficos e os motivos de permanência no referido programa. Os resultados revelaram que o bem-estar pessoal (91.9%) foi considerado o principal motivo para a manutenção da prática de exercícios físicos, entre todas as possibilidades existentes, seguido pela prevenção de doenças (82.8%), condicionamento físico (80.7%), empatia com o professor (79.2%), metodologia do trabalho desenvolvido (75.2%) e diversão (73.9%). Enquanto a prescrição médica tem alto potencial para estimular a inserção destes praticantes nos referidos programas, este motivo perde força no sentido de justificar a permanência da prática de exercícios físicos. Deste modo, é possível concluir que o bem-estar pessoal foi considerado o principal motivo alegado pelos participantes dos programas de exercícios físicos oferecidos pelo Serviço Social do Comércio - Brasil.

One of the concerns in the studies of adhesion lies in the investigation of the motives that justify continuation in physical exercise programs. The goal of this study was to identify motives influencing the continuation of adolescents, adults and the elderly in physical education programs offered by the Centers of Activity of Serviço Social do Comércio do Distrito Federal do Brasil. A representative and random sample of 986 individuals (between 15 and 89 years of age) answered a data collection instrument designed to investigate socio-demographic aspects and motives for permanence in the aforementioned program. Results showed personal wellbeing (91.9%) as the major reason for keeping up on practicing followed by prevention of illnesses (82.8%), physical conditioning (80.7%), empathy with the teacher (79.2%), program methodology (75.2%), and entertainment (73.9%). While medical exercise prescription highly influences people's entrance in these programs, it does not explain people's continuance.

The influence of molybdenum oxide as a promoter on the V2O5/Nb2O5 system was investigated. A series of MoO3/V2O5/Nb2 O5 catalysts, with MoO3 loading ranging from 1 to 3 wt% MoO3 and fixed V2O5 content (21 wt%), were prepared by impregnation of the Nb2O5 support with an aqueous solution of ammonium metavanadate and ammonium molybdate. The acid-base properties of the catalysts were investigated to determine of the selectivity of the isopropanol decomposition reaction. The X-ray diffraction results showed the presence of the beta-(Nb,V)2O5 phase. The temperature-programmed reduction profiles showed that the reducibility of vanadium was affected by the presence of molybdenum oxide. Activity results for isopropanol decomposition revealed that the acid-base properties of V2O5/Nb2O5 catalysts are affected upon incorporation of MoO3, specifically for loadings of 3 wt %. For this catalyst composition both propylene and acetone formation rates decreased.

Vanadium oxide supported on hydrotalcite-type precursors was studied in the oxidation of isopropanol. Hydrotalcites with different y = Mg/Al ratios were synthesized by the method of coprecipitation nitrates of Mg and Al cations with K2CO3 as precipitant. The decomposition of these hydrotalcite precursors at 450°C yielded homogeneous MgyAlOx mixed oxides that contain the Al+3 cations totally incorporated into the MgO framework. The materials were characterized by chemical analysis, BET superficial area, X-ray diffraction, temperature-programmed reduction (TPR) and the reaction of isopropanol, a probe molecule used to evaluate the acid-base properties. The results of TPR showed that the reducibility of V+5 decreased with the increase in magnesium loading in catalysts. The X-ray diffraction patterns of Al-rich hydrotalcite precursors showed the presence of crystalline phases of brucite and gibbsite. It was shown that chemical composition, texture, acid-base properties of the active sites and also Mg/Al ratio strongly affect the formation of the products in the oxidation of isopropanol. The Al-rich catalysts were much more active than the Mg-rich ones, converting isopropanol mainly to propylene.

Biomphalaria tenagophila é um hermafrodita simultâneo cujo investimento na função masculina foi avaliado pelo crescimento de seus órgãos sexuais em relação ao diâmetro da concha. Foram criadas novas técnicas para medir órgãos reprodutivos, sem aparentes distorções, e contar folículos do ovoteste. Durante o crescimento de espécimes sexualmente maduros de B. tenagophila, cresceu o número de folículos do ovoteste, mas seus números máximos e mínimos são menores do que os citados na literatura. O número de divertículos da próstata e de folículos do ovoteste de B. glabrata é maior do que o de B. tenagophila. Embora o comprimento do ovoteste, da próstata, da bainha do pênis e da glândula mucípara-ootecal variassem durante o crescimento do caramujo, não variou significativamente o número de divertículos da próstata.

Biomphalaria tenagophila is a simultaneous hermaphrodite whose's male function was evaluated by the growth of the sex organs in relation to the shell diameter. New techniques were applied to measure reproductive organs without apparent distorsion and to count individual ovotestis follicles. During the growth of sexually mature specimens of B. tenagophila the ovotestis follicles increased in number, but the maximum and minimum values are smaller than the ones found in the literature. The number of B. glabrata prostate diverticula and ovotestis follicles were greater than that of B. tenagophila. Although the length of ovotestis, prostate, penial sheath and muciparous-oothecal gland varied during B. tenagophila's growth, the number of prostate diverticula remained signifcantly stable.

Foram determinadas, na massa cefalopedal e na glândula digestiva de Biomphalaria glabrata de Touros (Rio Grande do Norte) B. tenagophila de Cacapava (Sao Paulo) e B. straminea de Monsenhor Gil (Piauí), as atividades específicas das seguintes enzimas: fosfatase acida, fosfatase alcalina, beta-glucuronidase, lisozima, transaminase glutâmico-oxalacetica e transaminase glutâmico-piruvica. As seis enzimas referidas foram detectadas no sobrenadante a 3000g. Ambas as enzimas citoplasmaticas - transaminases glutamico-oxalacetica e glutamico-piruvica - mostraram as atividades específicas mais altas. No caso das quatro enzimas hidrolíticas, a beta-glucuronidase revelou a mais alta atividade específica, enquanto a lisozima revelou a mais baixa. E admitido que todas as seis enzimas sao produzidas por celulas presentes na massa cefalopedal e na glândula digestiva das tres especies de moluscos examinadas.

The specific activities of acid phosphatase, alkaline phosphatase, β-glucuronidase, lysozymes, glutamate-oxalacetate transaminase and glutamate-pyruvate transaminate were determined in the head-foot and digestive gland of Brazilian Biomphalaria glabrata (Touros), B. tenagophila (Caçapava) and B. straminea (Monsenhor Gil). All six enzymes were detected inthe 3000g supernatant. Both cytoplasmic enzymes, glutamate-oxalacetate and glutamate-pyruvate transaminase exhibited the highest specific activities. In the case of the four hydrolytic enzymes assayed, β-glucuronidase exhibited the highest specific activity while lysozyme showed the lowest activity. All six enzymes are thought to be produced by cells within the head-foot and digestive gland of B. glabrata, B. tenagophila and B. straminea.