The effects of soil fumigation on the growth and mineral nutrition of weeds and crops

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Detection of Toxoplasma gondii in the reproductive system of male goats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Uncertainties in the prediction of spatial variability of soil CO2 emissions and related properties

A emissão de CO2 do solo apresenta alta variabilidade espacial, devido à grande dependência espacial observada nas propriedades do solo que a influenciam. Neste estudo, objetivou-se: caracterizar e relacionar a variabilidade espacial da respiração do solo e propriedades relacionadas; avaliar a acurácia dos resultados fornecidos pelo método da krigagem ordinária e simulação sequencial gaussiana; e avaliar a incerteza na predição da variabilidade espacial da emissão de CO2 do solo e demais propriedades utilizando a simulação sequencial gaussiana. O estudo foi conduzido em uma malha amostral irregular com 141 pontos, instalada sobre a cultura de cana-de-açúcar. Nesses pontos foram avaliados a emissão de CO2 do solo, a temperatura do solo, a porosidade livre de água, o teor de matéria orgânica e a densidade do solo. Todas as variáveis apresentaram estrutura de dependência espacial. A emissão de CO2 do solo mostrou correlações positivas com a matéria orgânica (r = 0,25, p < 0,05) e a porosidade livre de água (r = 0,27, p <0,01) e negativa com a densidade do solo (r = -0,41, p < 0,01). No entanto, quando os valores estimados espacialmente (N=8833) são considerados, a porosidade livre de água passa a ser a principal variável responsável pelas características espaciais da respiração do solo, apresentando correlação de 0,26 (p < 0,01). As simulações individuais propiciaram, para todas as variáveis analisadas, melhor reprodução das funções de distribuição acumuladas e dos variogramas, em comparação à krigagem e estimativa E-type. As maiores incertezas na predição da emissão de CO2 estiveram associadas às regiões da área estudada com maiores valores observados e estimados, produzindo estimativas, ao longo do período estudado, de 0,18 a 1,85 t CO2 ha-1, dependendo dos diferentes cenários simulados. O conhecimento das incertezas gerado por meio dos diferentes cenários de estimativa pode ser incluído em inventários de gases do efeito estufa, resultando em estimativas mais conservadoras do potencial de emissão desses gases.

Floral biology and breeding system of three Ipomoea weeds

A biologia floral de Ipomoea cairica, I. grandifolia e I. nil - plantas daninhas da família Convolvulaceae - foi estudada em Botucatu e Jaboticabal, Estado de São Paulo, Brasil. As três espécies são melitófilas, apresentando conjuntos de visitantes florais bastante diversificados, embora haja alguma sobreposição entre eles. Com relação aos visitantes florais, a análise de agrupamento, empregando-se o índice de similaridade de Jaccard, indicou maior similaridade entre diferentes espécies de Ipomoea ocorrentes no mesmo local do que entre populações da mesma espécie em diferentes localidades. O caráter promíscuo e oportunista da adaptação à polinização, presente nessas espécies, foi demonstrado, sendo essa adaptação vantajosa para plantas daninhas, uma vez que em ambientes ruderais a disponibilidade de polinizadores é imprevisível.

Cytogenetics of six Brazilian species of Psocoptera

The karyotypes of the following six species of Brazilian Psocoptera are reported: Caecillius sp. (Caecillidae), Triplocania ? caudata New (Ptiloneuridae), Brachinodiscus cf. lepidus (Banks) (Psocidae), Psococerastis interrupta New (Psocidae), Ptycta nr reticulata New (Psocidae) and Trichadenotecnum sinuatum New (Psocidae). All of them had males with 2n = 17 and an XO sex determining mechanism.

Morphology of the testicles of some brazilian species of Diplopoda and their phyllogenetic relations

The morphology of the testicles of some Brazilian species of Diplopoda is described. One type is scalariform, with two deferent ducts and the other consists of some single deferent duct. Phyllogenetic considerations on the structure are made.

Recovery of soil microbiological properties in a degraded area planted with Corymbia citriodora and Leucaena leucocephala

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The influence of soil and landfill leachate microorganisms in the degradation of PVC/PCL films cast from DMF

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

B-chromosomes in two Brazilian populations of Dendropsophus nanus (Anura, Hylidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Distribution of the Bari-I transposable element in stable hybrid strains between Drosophila melanogaster and Drosophila simulans and in Brazilian populations of these species

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Titi monkeys (Callicebus spp., Atelidae : Platyrrhini) in the Brazilian state of Rondonia

Five species of titi monkey (Callicebus brunneus, Callicebus caligatus, Callicebus cinerascens, Callicebus donacophilus, and Callicebus moloch) were recorded in surveys of primate populations at 26 sites throughout the Brazilian state of Rondonia. The distribution of the two species, C. cinerascens and C. donacophilus (recorded in the state for the first time), appeared to be related to that of non-forest ecosystems, the former in the cerrado woodlands, and the latter in gallery forests of the Guapore grasslands. The results of the surveys also indicate that C. brunneus has a more restricted distribution in southern Rondonia than was previously thought, whereas C. moloch is more widespread. However, the ecological factors that determine species distribution in the south of the state remain unclear on the basis of the available data. All species were observed in small social groups of no more than five individuals, which are typical of the genus, generally in the middle and lower forest strata.

LARVAL INSTARS AND IMMATURE DEVELOPMENT OF A BRAZILIAN POPULATION OF PHARAOHS ANT, MONOMORIUM-PHARAONIS (L) (HYM, FORMICIDAE)

The immature development of pharaoh's ant, Monomorium pharaonis, workers was s died in a naturally collected Brazilian population. Three larval instars were confirmed by measuring maximal cephalic widths in cohorts of known age. Minimum egg to adult duration was 25 days, while the maximum duration was 54 days, both of which are larger than those reported for European populations. Larval instar development is cyclical at the colony level, suggesting reproductive bursts followed by lower reproductive activity of the queens.

Characterization of esterases in a Brazilian population of Zaprionus indianus (Diptera : Drosophilidae)

The aim of this study was to characterize esterases in Zaprionus indianus, a drosophilid recently introduced into Brazil. A further aim was study the variation of activity of esterases in the presence of inhibitors and their expression according to sex, sexual activity and age of individual flies. Polymorphisms were detected in two esterase loci (Est-2 and Est-3) and monomorphisms in four others (Est-1, Est-4, Est-5 and Est-6). Biochemical tests using alpha- and beta-naphthyl acetate and the inhibitors malathion, eserine sulphate and PMSF allowed us to classify EST-2 and EST-5 as beta-esterases, both carboxyl-esterases, and EST-1, EST-3, EST-4 and EST-6 as alpha-esterases. EST-1 and EST-3 were classified as carboxyl-esterases and EST-4 and EST-6 as cholinesterases. EST-5 activity was more pronounced in males and EST-2 was restricted to them or to recently copulated females. EST-4, rarely detected, was not characterized. Based on their biochemical characteristics possible roles for these enzymes are suggested.

BOUSSINESQ-TYPE SYSTEM OF EQUATIONS IN THE BENARD-MARANGONI SYSTEM

A system of coupled evolution equations for the bulk velocity and the surface displacement is found to govern the long-wavelength perturbations in a Benard-Marangoni system. This system of equations, involving nonlinearity, dispersion, and dissipation, is a generalization of the usual Boussinesq system.