Ação de produtos químicos in vitro e in vivo sobre Clavibacter michiganensis subsp. michiganensis, agente causal do cancro bacteriano do tomateiro

O presente trabalho teve como objetivo avaliar a sensibilidade in vitro e in vivo de um isolado de Clavibacter michiganensis subsp. michiganensis (Cmm) aos produtos cloridrato de kasugamicina, fulusulfamide e oxitetraciclina. Para o teste in vitro, foram avaliados os halos de inibição formados ao redor de discos de papel de filtro umedecidos com os produtos, nas concentrações de 0, 1, 10, 100 e 1000 mig mL-1, 24 h após a instalação do ensaio. Quanto à avaliação dos produtos in vivo, dois ensaios foram instalados sob condições de casa-de-vegetação, com plantas de tomateiro cultivar Ângela Hiper, através da inoculação das plantas por dois métodos: pulverização foliar e ferimento no caule. Nos dois ensaios, as plantas foram pulverizadas com os produtos cloridrato de kasugamicina a 0,06 mL L-1, fulusulfamide a 0,025, 0,05 e 0,075 mL L-1 e oxitetraciclina a 0,40 g L-1, duas vezes antes e duas vezes após a inoculação, em intervalos médios de 5-7 dias. Foram avaliados a incidência de folíolos doentes (inoculação foliar) e a severidade dos sintomas nas plantas inoculadas por ferimento no caule. Verificou-se que o isolado de Cmm foi sensível in vitro ao cloridrato de kasugamicina, ao fulusulfamide e à oxitetraciclina, respectivamente a partir das concentrações de 1000, 100 e 10 mig mL-1. Com relação aos ensaios in vivo, apenas oxitetraciclina propiciou menor incidência de folíolos doentes nas plantas inoculadas através de pulverização foliar; nenhum produto teve êxito em controlar a doença nas plantas inoculadas por ferimento no caule. O fulusulfamide, em todas as concentrações, foi fitotóxico aos folíolos das plantas de tomateiro.

Caracterização físico-química da manga 'Tommy Atkins' submetida a aplicação de cloreto de cálcio pré-colheita e armazenamento refrigerado

Avaliou-se a qualidade pós-colheita de manga 'Tommy Atkins' submetida a aplicação pré-colheita de CaCl2 e armazenamento refrigerado. Os fatores estudados foram concentrações de CaCl2 (1% e 2%) e números de aplicações (2,3 e 4 vezes). Houve ainda um tratamento adicional, que funcionou como controle. As pulverizações foliares foram iniciadas cerca de 35 dias após antese, num intervalo de 15 dias. do total de 280 frutos colhidos, 175 foram levados para análise imediata, enquanto que 105 permaneceram em câmara fria (10ºC) por 30 dias, sendo posteriormente analisados. As concentrações de CaCl2 testadas não resultaram em incremento do teor de cálcio no fruto e também não influenciaram as características de qualidade avaliadas. Houve efeito do número de aplicações de CaCl2 sobre a textura, sólidos solúveis (após 30 dias) e açúcares solúveis totais (após a colheita). A incidência de colapso interno não foi associada a aplicação de cálcio.

Degradabilidade do capim-elefante em diferentes estágios de maturidade avaliada pelo método in vitro/gás

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

Desenvolvimento de mudas de bromélia (Neoregelia cruenta (R. Graham) L. B. Smith) cultivadas em diferentes substartos e adubação foliar

As bromélias apresentam formas exóticas com uma grande diversidade de cores e de flores, constituindo importantes espécies para uso em paisagismo e floricultura. em conseqüência disto, são muito comercializadas. Porém, parte das plantas que se encontram no mercado, ainda são provenientes do extrativismo. Esta situação é também reflexo do pequeno número de informações sobre técnicas de propagação e cultivo. Uma das limitações é o desconhecimento do tipo de substrato e adubação adequados ao cultivo destas espécies. Assim, o objetivo deste trabalho foi avaliar o crescimento de bromélias do Neoregelia cruenta, cultivadas em diferentes substratos e adubações foliares através da altura, do número de folhas, da matéria fresca e seca, da parte aérea e das raízes. As mudas utilizadas foram provenientes de cultura de tecidos. Após um período de pré-aclimatização, foram transplantadas para estufa sem nebulização. Os substratos foram constituídos da mistura de diferentes proporções de solo, areia, casca de arroz carbonizada e por um substrato comercial à base de vermiculita. Aos substratos foi aplicada adubação foliar, combinando uréia e sacarose, em intervalos de quinze dias. Os resultados obtidos mostraram que as interações entre os substratos, dose de sacarose e de uréia, não afetaram a altura das mudas e o número de folhas. O uso de sacarose também não influenciou o desenvolvimento das mudas. O substrato comercial à base de vermiculita, independente da aplicação de adubação foliar, proporcionou maior altura das mudas e número de folhas. A aplicação de uréia apresentou efeito linear crescente durante o período avaliado.

Variabilidade espacial da textura de um latossolo sob cultivo de citros

O relevo influencia a variabilidade da textura, uma vez que condiciona o tempo de exposição dos materiais à ação do intemperismo. Neste trabalho, desenvolvido no município de Gavião Peixoto (SP), objetivou-se caracterizar a variabilidade espacial da textura de um Latossolo Vermelho distrófico sob cultivo de citros. A encosta foi dividida em três segmentos: topo, meia encosta e encosta inferior. O solo foi amostrado em malha, com intervalos regulares de 50 m, perfazendo o total de 332 pontos em uma área de 83,5 ha, nas profundidades de 0,0-0,2 m e 0,6-0,8 m. Os dados foram submetidos à análise estatística descritiva e geoestatística (modelagem de semivariogramas e mapas de krigagem). O comportamento espacial da textura de latossolos está diretamente relacionado com as formas do relevo neste estudo, que controla o sentido dos fluxos de água superficial e subsuperficial. O conceito de homogeneidade da distribuição de argila no perfil dos latossolos é uma informação que pode ser ajustada pelo conhecimento do padrão espacial dessa distribuição em diferentes formas do relevo.

Pharmacological evidence for beta(2)-adrenoceptor in right atria from stressed female rats

The purpose of the present study was to demonstrate a physiological response to TA2005, a potent beta(2)-adrenoceptor (beta(2)-AR) selective agonist, in right atria isolated from stressed female rats under the influence of the estrous cycle. We obtained concentration-response curves to the agonist in the presence and in the absence of selective antagonists in right atria isolated from female rats submitted to three daily foot-shock sessions (30 min duration, 120 pulses of 1.0 mA, 1.0 s, applied at random intervals of 5-25 s) and sacrificed at estrus or diestrus. Our results showed that the pD(2), values of TA2005 were not influenced by estrous cycle phase or foot-shock stress. However, in right atria from stressed rats sacrificed during diestrus, the concentration-response curve to TA2005 was biphasic, with a response being obtained at concentrations of 0.1 nM, whereas during estrus no response was observed at doses lower than 3 nM. ICI118,551, a beta(2)-AR antagonist, abolished the response to nanomolar concentrations of TA2005 in right atria from stressed rats at diestrus, with no changes in a,agonist pot values in right atria from control rats (7.47 +/- 0.09, p > 0.05) but a 3-fold decrease in pD(2), values of TA2005 in right atria from foot shock stressed rats (7.90 +/- 0.07, p less than or equal to 0.05). Concentration-response curves to TA2005 in the presence of ICI118,551 were best fitted by a one-site model equation. The beta(1)-AR antagonist, CGP20712A, shifted to the right only the second part of the concentration-response curves to the agonist, unmasking the putative Pz-AR-mediated response to the agonist in tissues isolated from stressed rats at diestrus. Under this condition, concentration-response curves to the agonist were best fitted by a two-site model equation. pot and maximum response of TA2005 interaction with beta(1)- and putative Pz-adrenoceptor components were calculated. Schild analyses gave a pK(B) value for CGP20712A that was typical for the interaction with beta(1)-AR in each experimental group. pK(B), values for ICI118,551 could not be obtained in stressed rats sacrificed at diestrus since Schild plot slopes were lower than 1.0. In right atria from control rats, ICI118,551 pK(B), values were similar to reported values for the interaction of the antagonist with beta(1)-AR. These results confirm that a heterogenous PAR population mediating the chronotropic response to catecholamines can be demonstrated in right atria from foot shock stressed female rats sacrificed at diestrus. The stress-induced response seems to be mediated by the beta(2)-AR subtype. Right atria from rats sacrificed during estrus are protected against stress-induced alterations on the homogeneity of PAR population.

NEOCORTICAL SPINDLING DURING WAKEFULNESS IN THE RAT

Neocortical spindling that frequently occurs in rats during wakefulness was studied to evaluate the hypotheses that spindle bursts are either the electrophysiological manifestation of a short-lasting sleep episode that briefly interrupts wakefulness (due to an urge to sleep) or a short decrease of the vigilance level. In order to evaluate sleep need, the latency to the onset of natural sleep, the percentual composition of the sleep-wakefulness cycles, and the durations and intervals of desynchronized sleep episodes were determined in six male Wistar rats weighing 250-350 g and having chronically implanted electrodes for frontal electrocorticogram and cervical electromyogram. These animals were selected on the basis of spindling manifestation during wakefulness. The occurrence of spindling during a period of repeated painful tail-pinching was subsequently measured to determine the vigilance level in the same animals. Two rats were also studied during forced immobilization for the same purpose. Sleep parameters were found to be normal in all rats studied, thus excluding the hypothesis that spindling in wakefulness is a manifestation of a high sleep need. Spindling also occurred in both situations requiring a high level of vigilance (frequent tail-pinching and forced immobilization). Natural sleep cycles never started with this type of spindling, which is not related to the typical synchronization patterns of synchronized deep, the frequency of the potentials that make up spindles in wakefulness were systematically 1 to 2 Hz lower than those of synchronized sleep in all animals studied. The possibility that spindling during wakefulness may be associated to brief episodes of distraction is discussed.

Path formulation for Z(2) circle plus Z(2)-equivariant bifurcation problems

M. Manoel and I. Stewart 0101) classify Z(2) circle plus Z(2)-equivariant bifurcation problems up to codimension 3 and 1 modal parameter, using the classical techniques of singularity theory of Golubistky and Schaeffer [8]. In this paper we classify these same problems using an alternative form: the path formulation (Theorem 6.1). One of the advantages of this method is that the calculates to obtain the normal forms are easier. Furthermore, in our classification we observe the presence of only one modal parameter in the generic core. It differs from the classical classification where the core has 2 modal parameters. We finish this work comparing our classification to the one obtained in [10].

Efeito da palpação retal e da frequencia de inseminações na fertilidade de éguas inseminadas com sêmen fresco diluído

Forty-two mares were randomly assigned in a 3 x 2 factorial experiment which included three intervals between rectal palpation (6/6h, 12/12h and once a day palpation) and two frequencies of inseminations (daily or every other day). The mares were inseminated with semen from only one stallion, diluted in minimal contamination extender. There were no differences in the conception rate at first cycle, conception/cycle, conception total, efficiency of pregnancy in either system of rectal palpation, independently of the frequency of insemination utilized. Also there were no differences among intervals of rectal palpation concerning the following reproductive characteristics: number of cycles/mare, cycles/pregnant mare, cycles/ pregnancy, pregnancy/cycle, number of inseminations/mare, inseminations/ pregnant mare and insemination/open mare. There were no differences in pregnancy rate at first cycle, pregnancy rate/cycle, pregnancy rate total and efficiency of pregnancy between the two frequency of insemination. However, the frequency of insemination influenced the number of inseminations/mare, number of inseminations/ pregnant mare and inseminations/open mare. The highest values were observed with the mares inseminated daily. Therefore, insemination every other day can be recommended. If necessary the mare may be palpated rectally at intervals of six hours without reducing the pregnancy rate.

Genetic parameters for milk yield, age at first calving and interval between first and second calving in milk buffaloes

Genetic parameters for the relation between the traits of milk yield (MY), age at first calving (AFC) and interval between first and second calving (IBFSC) were estimated in milk buffaloes of the Murrah breed. In the study, data of 1578 buffaloes at first lactation, with calvings from 1974 to 2006 were analyzed. The MTDFREML system was used in the analyses with models for the MY, IBFSC traits which included the fixed effects of herd-year-season of calving, linear and quadratic terms of calving age as covariate and the random animal effects and error. The model for AFC consisted of the herd-year-season fixed effects of calving and the random effects of animal and error. Heritability estimates MY, AFC and IBFSC traits were 0.20, 0.07 and 0.14, respectively. Genetic and phenotypic correlations between the traits were: MY and AFC = -0.12 and -0.15, MY and IBFSC = 0.07 and 0.30, AFC and IBFSC = 0.35 and 0.37, respectively. Genetic correlation between MY and AFC traits showed desirable negative association, suggesting that the daughters of the bulls with high breeding value for MY could be physiological maturity to a precocious age. Genetic correlation between MY and IBFSC showed that the selection of the animals that increased milk yield is also those that tend to intervals of bigger calving.

Non-exhaustive test for aerobic capacity determination in swimming rats

The aim of this study was to describe a double-bout exercise test for non-exhaustive aerobic capacity determination in swimming rats. Adult rats were Submitted to 4 swimming tests at different intensities (4%, 6%, 7%, and 8% of body mass), with intervals of 48 h between them. Two exercise bouts of equal intensity lasting 5 min were performed, separated by 2 min with blood collection for lactate analysis. For each intensity, delta lactate was determined by subtracting lactate concentration at the end of the first effort from the lactate at the end of the second effort. Individual linear interpolation of delta lactate concentration enabled determination of a null delta, equivalent to the critical load (CL). Maxima) lactate steady state (MLSS) was also determined. The estimated CL was of 4.8% body mass and the MLSS was observed at 100% of CL, with blood lactate of 5.20 mmol/L. At 90%, blood lactate stabilized, with a progressive increase to 110% CL. These results offer a potential determination of aerobic capacity in swimming rats.

Atividade microbiana em solos, influenciada por resíduos de algodão e torta de mamona

Microbial activity constitutes a good indicator of soil quality, and is influenced by the addition of carbon in the system serving as a substrate for microorganisms that increase their activity and release of CO2, comprising the edaphic respiration of the soil. The objective of this study was to evaluate the microbial activity in different soil types with the addition of cake press of castor bean and cotton textile residue. The study was conducted in a greenhouse at the headquarters of Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) Cotton in randomized block design in 4 x 3 factorial arrangement with four replications. At predetermined intervals of 4 days, the containers were opened and the solution of NaOH titrated with HCl 2N in the presence of acid/base indicator phenolphthalein. After reading, the same amount of NaOH was added and the containers were closed again. The difference between the amounts of acid needed to neutralize the sodium hydroxide in a control container and the treatments was equivalent to the amount of carbon dioxide produced by soil microorganisms. It was found that the residues influenced the microbial activity in different soil types, especially in the initial determinations, presenting themselves as good sources for mineralization and nutrient supply, the castor bean proportionating higher cumulative release of CO2 by microorganisms.

Pharmacological evidence for β2-adrenoceptor in right atria from stressed female rats

The purpose of the present study was to demonstrate a physiological response to TA2005, a potent β2-adrenoceptor (β2-AR) selective agonist, in right atria isolated from stressed female rats under the influence of the estrous cycle. We obtained concentration-response curves to the agonist in the presence and in the absence of selective antagonists in right atria isolated from female rats submitted to three daily foot-shock sessions (30 min duration, 120 pulses of 1.0 mA, 1.0 s, applied at random intervals of 5- 25 s) and sacrificed at estrus or diestrus. Our results showed that the pD2 values of TA2005 were not influenced by estrous cycle phase or foot-shock stress. However, in right atria from stressed rats sacrificed during diestins, the concentration-response curve to TA2005 was biphasic, with a response being obtained at concentrations of 0.1 nM, whereas during estrus no response was observed at doses lower than 3 nM. ICI118,551, a β2-AR antagonist, abolished the response to nanomolar concentrations of TA2005 in right atria from stressed rats at diestrus, with no changes in agonist pD2 values in right atria from control rats (7.47 ± 0.09, p > 0.05) but a 3-fold decrease in pD2 values of TA2005 in right atria from foot shock stressed rats (7.90 ± 0.07, p ≤ 0.05). Concentration-response curves to TA2005 in the presence of ICI118,551 were best fitted by a one-site model equation. The β1-AR antagonist, CGP20712A, shifted to the right only the second part of the concentration-response curves to the agonist, unmasking the putative β2-AR-mediated response to the agonist in tissues isolated from stressed rats at diestrus. Under this condition, concentration-response curves to the agonist were best fitted by a two-site model equation, pD2 and maximum response of TA2005 interaction with β1- and putative β2-adrenoceptor components were calculated. Schild analyses gave a pK(B) value for CGP20712A that was typical for the interaction with β1-AR in each experimental group, pK(B) values for ICI118,551 could not be obtained in stressed rats sacrificed at diestins since Schild plot slopes were lower than 1.0. In right atria from control rats, ICI118,551 pK(B) values were similar to reported values for the interaction of the antagonist with β1-AR. These results confirm that a heterogenous β1-AR population mediating the chronotropic response to catecholamines can be demonstrated in right atria from foot shock stressed female rats sacrificed at diestins. The stress-induced response seems to be mediated by the β2-AR subtype. Right atria from rats sacrificed during estrus are protected against stress-induced alterations on the homogeneity of β-AR population.

Germinative pretreatments to dormancy break in Guazuma ulmifolia Lam. seeds

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Contribuição ao protocolo de controle de qualidade da própolis e de seus extratos

A quality control protocol for the analysis of propolis and its extracts is proposed in the present work. Propolis of Apis mellifera L. bees collected in beehives of an apiary located in the northwest of the Paraná State was triturated and submitted to the following analysis: particles medium size determination, loss of dry, ashes drift, waxes drift, drift of extractive (in water and in ethanol) and total flavonoids drift determination. Propolis ethanolic extracts (96 °GL) at 10% (w/w) and at 30% (w/w) were prepared and submitted to the determination of the pH, relative density, dry residue, alcoholic drift and total flavonoids drift determination. Propolis was analyzed, through High Performance Liquid Cromatography (HPLC). Comparing the obtained results with other works, it was observed that is possible to establish the intervals of values for parameters in order to evaluate the quality of a propolis sample and its extracts.