87 research outputs found

    Caffeine inheritance in interspecific hybrids of Coffea arabica x Coffea canephora (Gentianales, Rubiaceae)

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    Caffeine inheritance was investigated in F2 and BC1F1 generations between Coffea arabica var. Bourbon Vermelho (BV) and Coffea canephora var. Robusta 4x (R4x). The caffeine content of seeds and leaves was determined during 2004 and 2005. Microsatellite loci-markers were used to deduce the meiotic pattern of chromosome pairing of tetraploid interspecific hybrids. Genetic analysis indicated that caffeine content in seeds was quantitatively inherited and controlled by genes with additive effects. The estimates of broad-sense heritability of caffeine content in seeds were high for both generations. In coffee leaves, the caffeine content (BSH) from the same populations showed transgressive segregants with enhanced levels and high BSH. Segregation of loci-markers in BC1F1 populations showed that the ratios of the gametes genotype did not differ significantly from those expected assuming random associations and tetrasomic inheritance. The results confirm the existence of distinct mechanisms controlling the caffeine content in seeds and leaves, the gene exchange between the C. arabica BV and C. canephora R4x genomes and favorable conditions for improving caffeine content in this coffee population312498504CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQsem informaçã

    Verbal and visual stimulation effects on rectus femoris and biceps femoris muscles during isometric and concentric

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    Abstract Background: Coactivation may be both desirable (injury prevention) or undesirable (strength measurement). In this context, different styles of muscle strength stimulus have being investigated. In this study we evaluated the effects of verbal and visual stimulation on rectus femoris and biceps femoris muscles contraction during isometric and concentric. Methods: We investigated 13 men (age =23.1 ± 3.8 years old; body mass =75.6 ± 9.1 kg; height =1.8 ± 0.07 m). We used the isokinetic dynamometer BIODEX device and an electromyographic (EMG) system. We evaluated the maximum isometric and isokinetic knee extension and flexion at 60°/s. The following conditions were evaluated: without visual nor verbal command (control); verbal command; visual command and; verbal and visual command. In relation to the concentric contraction, the volunteers performed five reciprocal and continuous contractions at 60°/s. With respect to isometric contractions it was made three contractions of five seconds for flexion and extension in a period of one minute. Results: We found that the peak torque during isometric flexion was higher in the subjects in the VVC condition (p > 0.05). In relation to muscle coactivation, the subjects presented higher values at the control condition (p > 0.05). \ud \ud \ud Conclusion\ud We suggest that this type of stimulus is effective for the lower limbs.This study received financial support from Universidade do Vale do Paraíba

    Diferenças na infestação de Aphis gossypii em plantas de algodoeiro cultivar 'IAC-RM3' tratadas com reguladores de crescimento

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    We have studied the effect of application of growth regulators, (2-chloroethyl) trimethylammonium chloride (CCC), N,N-dimethylaminosuccinamic acid (SADH), gibberellic acid (GA3) and 3-indoleacetic acid (IAA) on cotton, Gossypium hirsutum L. cv. 'IAC-RM3', in relation to atack of Aphis gossypii Glover, 1876, under greenhouse conditions. Two determinations of infestation levels of the aphids showed differences in degree of infestation among treatments. CCC treated plants showed increasing in aphid colonization in relation to GA3 at 100 ppm treated plants. The application of SADH at 4000 ppm also showed a tendency of increasing aphid colonization in relation to treated plants with GA3 at 100 ppm. Probably growth retardants promote differences in the water status of hostplant; and the aphids preferences to that plants suggest that the increase in the osmotic potential promotes better rates of aphid feeding than GA3 treated plants. In treated plants with GA3 at 100 ppm the infestation decreased, there was water stress during the warmer time of the day and a probable decreasing in the osmotic potential.Estudou-se a influência da aplicação de reguladores de crescimento (CCC, SADH, GA3 e IAA) em algodoeiro, Gossypium hirsutum L. cv. 'IAC-RM3', na infestação de Aphis gossypii Glover, 1876; em condições de casa de vegetação. A realização de duas determinações no nível de infestação dos afídios, evidenciou que plantas tratadas com CCC mostram níveis superiores de infestação com relação às tratadas com GA3 a 100 ppm; sendo que a aplicação de SADH a 4000 ppm também promoveu uma tendência de maior infestação com relação ao GA3 a 100 ppm. Estes resultados parecem revelar que os retardadores de crescimento promovem um equilíbrio hídrico interno nas plantas mais favorável, mantendo o potencial osmótico mais elevado e possibilitando uma melhor alimentação do afídio. Plantas tratadas com GAg a 100 ppm parecem sofrer maiores déficits hídricos, não favorecendo o estabelecimento das colônias, nas condições estudadas

    Beyond the ‘East-West’ dichotomy: global variation in cultural models of selfhood

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    Markus and Kitayama’s (1991) theory of independent and interdependent self-construals had a major influence on social, personality, and developmental psychology by highlighting the role of culture in psychological processes. However, research has relied excessively on contrasts between North American and East Asian samples, and commonly used self-report measures of independence and interdependence frequently fail to show predicted cultural differences. We revisited the conceptualization and measurement of independent and interdependent self-construals in 2 large-scale multinational surveys, using improved methods for cross-cultural research. We developed (Study 1: N = 2924 students in 16 nations) and validated across cultures (Study 2: N = 7279 adults from 55 cultural groups in 33 nations) a new 7-dimensional model of self-reported ways of being independent or interdependent. Patterns of global variation support some of Markus and Kitayama’s predictions, but a simple contrast between independence and interdependence does not adequately capture the diverse models of selfhood that prevail in different world regions. Cultural groups emphasize different ways of being both independent and interdependent, depending on individualism-collectivism, national socioeconomic development, and religious heritage. Our 7-dimensional model will allow future researchers to test more accurately the implications of cultural models of selfhood for psychological processes in diverse ecocultural contexts

    Secreted Human Amyloid Precursor Protein Binds Semaphorin 3a and Prevents Semaphorin-Induced Growth Cone Collapse

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    The amyloid precursor protein (APP) is well known for giving rise to the amyloid-β peptide and for its role in Alzheimer's disease. Much less is known, however, on the physiological roles of APP in the development and plasticity of the central nervous system. We have used phage display of a peptide library to identify high-affinity ligands of purified recombinant human sAPPα695 (the soluble, secreted ectodomain from the main neuronal APP isoform). Two peptides thus selected exhibited significant homologies with the conserved extracellular domain of several members of the semaphorin (Sema) family of axon guidance proteins. We show that sAPPα695 binds both purified recombinant Sema3A and Sema3A secreted by transfected HEK293 cells. Interestingly, sAPPα695 inhibited the collapse of embryonic chicken (Gallus gallus domesticus) dorsal root ganglia growth cones promoted by Sema3A (Kd≤8·10−9 M). Two Sema3A-derived peptides homologous to the peptides isolated by phage display blocked sAPPα binding and its inhibitory action on Sema3A function. These two peptides are comprised within a domain previously shown to be involved in binding of Sema3A to its cellular receptor, suggesting a competitive mechanism by which sAPPα modulates the biological action of semaphorins

    In the context of a daycare center: nursing and their representations of child care as an educational act

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    This study aimed to analyze the social representations in the professionals of technical staff, who work with children at USP daycare centers. Eight professionals of the nursing field underwent a semi-structured interview. The interviews were recorded and transcribed in their entirety and the content of the discourse was subjected to thematic-categorical analysis. The categories were transformed into variables and processed by the software Classification Hiérarchique Classificatoire et Cohésitive (CHIC®) and analyzed by the hierarchical similarity tree. The results indicate that actions to promote health are reported as educational and transformative, in which health care gains new meaning through contextualized conceptions in the field of child education. We conclude that professionals attribute new meanings to their practices in the health care environment of daycare centers as their representations shifts from the logic of the biomedical field to a logic of educational care. In this sense, they perceive themselves as being challenged to establish an interaction with the children in terms of their activities related to the promotion of health and in an educational act
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