Vector competence of Culex quinquefasciatus Say, 1823 exposed to different densities of microfilariae of Dirofilaria immitis (Leidy, 1856)

The metropolitan region of Recife, Brazil is endemic for Dirofilaria immitis and has an environment favorable to the development of Culex quinquefasciatus. The goal of this study was to evaluate the vector competence of the Cx. quinquefasciatus RECIFE population for D. immitis transmission. A total of 2,104 females of Cx. quinquefasciatus RECIFE population were exposed to different densities of D. immitis microfilariae blood meals, ranging from 1,820 to 2,900 mf/ml of blood, in a natural membrane apparatus. The results showed a variation between 92.3% and 98.8% of females fed. The exposure of the Cx. quinquefasciatus RECIFE population to different densities of microfilariae did not influence the mortality of the mosquitoes. Infective larvae from D. immitis were observed in the Malpighian tubules beginning on the 12th day, whereas larvae were observed in the head and proboscis beginning on the 13th day following infection. The vector efficiency index (VEI) presented by the mosquitoes ranged from 7.8 to 56.5. The data demonstrates that the Cx. quinquefasciatus RECIFE population has great potential for the transmission of D. immitis, as it allowed the development of the filarid until the infectious stage at the different densities of microfilariae to which it was exposed.

Spatial evaluation of larvae of Culicidae (Diptera) from different breeding sites: application of a geospatial method and implications for vector control

Spatial evaluation of Culicidae (Diptera) larvae from different breeding sites: application of a geospatial method and implications for vector control. This study investigates the spatial distribution of urban Culicidae and informs entomological monitoring of species that use artificial containers as larval habitats. Collections of mosquito larvae were conducted in the São Paulo State municipality of Santa Bárbara d' Oeste between 2004 and 2006 during house-to-house visits. A total of 1,891 samples and nine different species were sampled. Species distribution was assessed using the kriging statistical method by extrapolating municipal administrative divisions. The sampling method followed the norms of the municipal health services of the Ministry of Health and can thus be adopted by public health authorities in disease control and delimitation of risk areas. Moreover, this type of survey and analysis can be employed for entomological surveillance of urban vectors that use artificial containers as larval habitat.

State-space approach to evaluate the relation between soil physical and chemical properties

The state-space approach is used to evaluate the relation between soil physical and chemical properties in an area cultivated with sugarcane. The experiment was carried out on a Rhodic Kandiudalf in Piracicaba, State of São Paulo, Brazil. Sugarcane was planted on an area of 0.21 ha i.e., in 15 rows 100 m long, spaced 1.4 m. Soil water content, soil organic matter, clay content and aggregate stability were sampled along a transect of 84 points, meter by meter. The state-space approach is used to evaluate how the soil water content is affected by itself and by soil organic matter, clay content, and aggregate stability of neighboring locations, in different combinations, aiming to contribute to a better understanding of the relation among these variables in the soil. Results show that soil water contents were successfully estimated by this approach. Best performances were found when the estimate of soil water content at locations i was related to soil water content, clay content and aggregate stability at locations i-1. Results also indicate that this state-space model using all series describes the soil water content better than any equivalent multiple regression equation.

Compared performance of penetrometers and effect of soil water content on penetration resistance measurements

Modern agriculture techniques have a great impact on crops and soil quality, especially by the increased machinery traffic and weight. Several devices have been developed for determining soil properties in the field, aimed at managing compacted areas. Penetrometry is a widely used technique; however, there are several types of penetrometers, which have different action modes that can affect the soil resistance measurement. The objective of this study was to compare the functionality of two penetrometry methods (manual and automated mode) in the field identification of compacted, highly mechanized sugarcane areas, considering the influence of soil water volumetric content (θ) on soil penetration resistance (PR). Three sugarcane fields on a Rhodic Eutrudrox were chosen, under a sequence of harvest systems: one manual harvest (1ManH), one mechanized harvest (1MH) and three mechanized harvests (3MH). The different degrees of mechanization were associated to cumulative compaction processes. An electronic penetrometer was used on PR measurements, so that the rod was introduced into the soil by hand (Manual) and by an electromechanical motor (Auto). The θ was measured in the field with a soil moisture sensor. Results showed an effect of θ on PR measurements and that regression models must be used to correct data before comparing harvesting systems. The rod introduction modes resulted in different mean PR values, where the "Manual" overestimated PR compared to the "Auto" mode at low θ.

Violência escolar e auto-estima de adolescentes

Este artigo procura estudar a associação entre auto-estima e violências que ocorrem no ambiente escolar. Apresenta resultados obtidos em pesquisa realizada em escolas públicas e particulares de São Gonçalo, Estado do Rio de Janeiro. Emprega basicamente metodologia quantitativa (inquérito epidemiológico com uma amostra de 1.686 alunos) com alunos das 7ª e 8ª séries do ensino fundamental e 1º e 2º anos do ensino médio. Os resultados indicam que alunos com baixa auto-estima relacionam-se de forma pior com colegas e professores que os pares de elevada auto-estima, além de se colocarem mais freqüentemente na posição de vítimas de violência na escola e terem mais dificuldade de se sentir bem no espaço escolar. São apontados alguns programas nacionais que têm tentado abordar o problema da violência na escola.

O auto-respeito na escola

Estudo com objetivo de identificar os valores presentes na escola e verificar quais interações favorecem a construção e ou a manutenção dos valores morais em particular o auto-respeito. Com enfoque teórico da Psicologia Socioistórica, a investigação apoiou-se nos estudos sobre moralidade de Jean Piaget e Yves de la Taille e constatou que coexistem na escola interações favorecedoras e não favorecedoras da construção de valores morais sendo que as últimas são mais freqüentes.

Processo de criação organizacional e processo de auto-organização

Neste trabalho, procura-se conhecer como o processo de criação é tratado na organização social, estudar um modelo proposto de criação organizacional e identificar o processo de auto-organização no processo de criação da organização social.

Stability and adaptability of runner peanut genotypes based on nonlinear regression and AMMI analysis

The objective of this work was to estimate the stability and adaptability of pod and seed yield in runner peanut genotypes based on the nonlinear regression and AMMI analysis. Yield data from 11 trials, distributed in six environments and three harvests, carried out in the Northeast region of Brazil during the rainy season were used. Significant effects of genotypes (G), environments (E), and GE interactions were detected in the analysis, indicating different behaviors among genotypes in favorable and unfavorable environmental conditions. The genotypes BRS Pérola Branca and LViPE‑06 are more stable and adapted to the semiarid environment, whereas LGoPE‑06 is a promising material for pod production, despite being highly dependent on favorable environments.

Random regression models to estimate genetic parameters for milk production of Guzerat cows using orthogonal Legendre polynomials

The objective of this work was to compare random regression models for the estimation of genetic parameters for Guzerat milk production, using orthogonal Legendre polynomials. Records (20,524) of test-day milk yield (TDMY) from 2,816 first-lactation Guzerat cows were used. TDMY grouped into 10-monthly classes were analyzed for additive genetic effect and for environmental and residual permanent effects (random effects), whereas the contemporary group, calving age (linear and quadratic effects) and mean lactation curve were analized as fixed effects. Trajectories for the additive genetic and permanent environmental effects were modeled by means of a covariance function employing orthogonal Legendre polynomials ranging from the second to the fifth order. Residual variances were considered in one, four, six, or ten variance classes. The best model had six residual variance classes. The heritability estimates for the TDMY records varied from 0.19 to 0.32. The random regression model that used a second-order Legendre polynomial for the additive genetic effect, and a fifth-order polynomial for the permanent environmental effect is adequate for comparison by the main employed criteria. The model with a second-order Legendre polynomial for the additive genetic effect, and that with a fourth-order for the permanent environmental effect could also be employed in these analyses.

Evidência da atuação do sistema de auto-incompatibilidade tardia em Acca Sellowiana (berg) burret. (Myrtaceae)

Acca sellowiana (Myrtaceae) é uma frutífera nativa da região Sul do Brasil e nordeste do Uruguai, que vem despertando grande interesse devido ao alto potencial organoléptico de seus frutos. Neste trabalho, teve-se como objetivo a caracterização do tipo de sistema de incompatibilidade atuante em A. sellowiana, através da avaliação do desenvolvimento dos tubos polínicos. Utilizaram-se dois acessos: 458, sendo autocompatível, e 101, auto-incompatível. A maior porcentagem de germinação de grãos de pólen foi observada no acesso 101, com 68,8% de grãos de pólen germinados. Não foram observadas diferenças no crescimento dos tubos polínicos em pistilos autopolinizados ou de polinização cruzada, em ambos os acessos. O crescimento completo do tubo polínico até o ovário ocorreu em pistilos coletados 96 horas após a polinização, independentemente do tratamento aplicado. Sugere-se a ocorrência de auto-esterilidade ou auto-incompatibilidade tardia ou pós-zigótica, considerando que o abortamento dos frutos de A. sellowiana é uniforme e ocorre num prazo curto, por volta de 20 a 30 dias após a fertilização das flores.

Importância da ecogenicidade da tireóide no diagnóstico da tireoidite crônica auto-imune

A tireoidite crônica auto-imune é, atualmente, a principal causa de hipotireoidismo e seu diagnóstico baseia-se nas manifestações clínico-laboratoriais. O marcador laboratorial mais importante é a presença de anticorpos antitireoglobulina e antiperoxidase, sendo este último o teste mais sensível. A biópsia aspirativa apresenta alta sensibilidade e especificidade, porém, é um método invasivo e, por isso, reservado para quando há presença de nódulo ou bócio de crescimento rápido. A cintilografia é desnecessária para o diagnóstico, já que apresenta baixa sensibilidade e especificidade. A ultra-sonografia, tanto ao modo B como ao dúplex-Doppler colorido, evoluiu de forma muito rápida e tornou-se um método simples, não-invasivo, reprodutível e com alta sensibilidade para o diagnóstico da tireoidite crônica auto-imune. Ao modo B, a ecogenicidade é um parâmetro de extrema importância, já que, além de apresentar alta correlação com o quadro citopatológico, também apresenta alta sensibilidade para o diagnóstico da tireoidite crônica auto-imune. Embora este parâmetro não seja específico da tireoidite crônica auto-imune, pois também pode estar presente na doença de Graves, na tireoidite pós-parto e na tireoidite subaguda, tais desordens podem ser facilmente diferenciadas tanto pelo quadro clínico-laboratorial quanto pelo dúplex-Doppler colorido. Assim, este artigo tem o objetivo de revisar a importância do estudo da ecogenicidade no diagnóstico da tireoidite crônica auto-imune.

Cinética e mecanismo da reação de auto-oxidação de S(IV) catalisada por íons metálicos de transição

The oxidation process of sulfur (IV) species (SO2, HSO3- e SO32-) by oxygen, catalysed by trace metal ion and complexes, can play an important role in atmospheric, analytical and bioinorganic chemistry. An overview of the most important reactions in these fields is presented. A fascinating redox cycling of the metal ions and complexes during such autoxidation process was revealed by the combination of kinetics and coordination chemistry studies.

Emprego de monocamadas auto-organizadas no desenvolvimento de sensores eletroquímicos

Self-assembled monolayers (SAMs) modified electrodes exhibit unique behavior that can greatly benefit electrochemical sensing. This brief review highlights the applications of SAM modified electrodes in electroanalytical chemistry. After a general introduction, which includes the approaches for SAM development, different electrochemical systems for detecting inorganic and organic species are described and discussed. Special attention to the coupling of biological sensing element to the SAM is given, which can selectively recognize the analyte. Future prospects are also evaluated.

LS-SVM: uma nova ferramenta quimiométrica para regressão multivariada. Comparação de modelos de regressão LS-SVM e PLS na quantificação de adulterantes em leite em pó empregando NIR

Least-squares support vector machines (LS-SVM) were used as an alternative multivariate calibration method for the simultaneous quantification of some common adulterants found in powdered milk samples, using near-infrared spectroscopy. Excellent models were built using LS-SVM for determining R², RMSECV and RMSEP values. LS-SVMs show superior performance for quantifying starch, whey and sucrose in powdered milk samples in relation to PLSR. This study shows that it is possible to determine precisely the amount of one and two common adulterants simultaneously in powdered milk samples using LS-SVM and NIR spectra.

Auto-associação do dodecilsulfato de sódio (SDS) com o polímero hidrofobicamente modificado etil(hidroxietil) celulose (EHEC)

Mixtures of ethyl(hydroxyethyl)cellulose (EHEC) and Sodium Dodecyl Sulfate (SDS) were investigated using surface tension, conductivity and viscosity measurements in aqueous solutions. The parameters of the surfactant to polymer association processes such as the critical aggregation concentration (cac) and saturation of the polymer by SDS (psp) were determined from the plots of surface tension and specific conductivity versus surfactant concentration. Through the final results we see that there was no specific link of polymer with the surfactant, implying therefore a phenomenon of only cooperative association.