Search

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:49:57Z No. of bitstreams: 1 S0100-69162004000100017.pdf: 157964 bytes, checksum: 95399b628c49b53b37e6e59d43ba469f (MD5) Made available in DSpace on 2013-08-22T18:49:57Z (GMT). No. of bitstreams: 1 S0100-69162004000100017.pdf: 157964 bytes, checksum: 95399b628c49b53b37e6e59d43ba469f (MD5) Previous issue date: 2004-04-01 Made available in DSpace on 2013-09-30T17:43:53Z (GMT). No. of bitstreams: 2 S0100-69162004000100017.pdf: 157964 bytes, checksum: 95399b628c49b53b37e6e59d43ba469f (MD5) S0100-69162004000100017.pdf.txt: 30921 bytes, checksum: 6e305144614aaa9c895d121378b24894 (MD5) Previous issue date: 2004-04-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:14:27Z No. of bitstreams: 2 S0100-69162004000100017.pdf: 157964 bytes, checksum: 95399b628c49b53b37e6e59d43ba469f (MD5) S0100-69162004000100017.pdf.txt: 30921 bytes, checksum: 6e305144614aaa9c895d121378b24894 (MD5) Made available in DSpace on 2014-05-20T13:14:27Z (GMT). No. of bitstreams: 2 S0100-69162004000100017.pdf: 157964 bytes, checksum: 95399b628c49b53b37e6e59d43ba469f (MD5) S0100-69162004000100017.pdf.txt: 30921 bytes, checksum: 6e305144614aaa9c895d121378b24894 (MD5) Previous issue date: 2004-04-01 O trabalho teve o objetivo de avaliar a demanda energética e a eficiência da distribuição de sementes de uma semeadora-adubadora para semeadura direta, submetida à variação de velocidade e condições de solo, na semeadura da cultura do milho. O estudo foi desenvolvido em um Nitossolo Vermelho distrófico, na Fazenda Experimental Lageado, no município de Botucatu - SP. O delineamento experimental foi em blocos casualizados, com oito repetições, combinando-se três velocidades de deslocamento (4,4; 6,1 e 8,1 km h-1) e duas condições de solo (solo manejado sob sistema de plantio direto há cinco anos e solo preparado com escarificador há 18 meses). Avaliaram-se a força de tração, a potência na barra de tração, o consumo de combustível, a capacidade de campo efetiva, a distribuição longitudinal de plantas, o coeficiente de variação, o índice de precisão e o número de plantas por hectare (estande inicial). Os resultados revelaram que, aumentando-se a velocidade de 4,4 para 8,1 km h-1, consegue-se aumentar em 86% a capacidade operacional, com incremento de 96% na demanda de potência na barra de tração e redução de 26% no consumo operacional de combustível. A maior velocidade (8,1 km h-1) proporcionou menor porcentual de espaçamentos normais e aumento no porcentual de espaçamentos múltiplos e falhos, maior coeficiente de variação e pior índice de precisão. A variação da velocidade não interferiu no número de plantas por hectare. This work evaluated the energetic demand and distribution efficiency of corn seeds in a no-till seeder when submitted to travel speed and soil condition variation. The study was developed in a soil classified as Ultissoil, at Fazenda Experimental Lageado, Botucatu Country, São Paulo State, Brazil. The experimental design was in a randomized block with eight repetitions, being the treatments a combination of three displacement speeds (4.4; 6.1 and 8.1 km h-1) and two soil conditions (soil carried out under no tillage system during those last five years, soil prepared with chisel plow 18 months before seeding). Parameters of traction force, power, fuel consumption, effective field capacity, longitudinal distribution of plants, variation coefficient, precision index and initial plants stand were appraised. The results showed that increasing the speed of 4.4 to 8.1 km h-1, increases 86% the operational capacity of the group tractor/seeder, increasing 96% the power demand in the traction bar and reduction of 26% in the operational fuel consumption. The fastest speed (8.1 km h-1) provided a smaller percentile of normal spacing and an increasing in the percentile of multiple and fail spacing, larger variation coefficient and worse precision index. The speed variation didn't interfere in the plant stand. Universidade Estadual Paulista FCA Universidade Estadual Paulista FCA Departamento de Engenharia Rural Universidade Estadual Paulista FCAV Departamento de Engenharia Rural Universidade Estadual Paulista FCA Universidade Estadual Paulista FCA Departamento de Engenharia Rural Universidade Estadual Paulista FCAV Departamento de Engenharia Rural

This article reports an outbreak of intoxication of female horses with Claviceps purpurea in southern Brazil. The outbreak affected twelve pregnant mares which were fed with black oat (Avena strigosa) during the pre-delivery period. Underdevelopment of the mammary gland in the pre-delivery period resulting in post-delivery agalactia was the most pronounced finding. These mares delivered weak and unviable foals, which showed no suckling reflex and died within a few hours of birth. Laboratory analysis of oat samples fed to the animals resulted in the identification of Claviceps purpurea sclerotia. The fungus was identified in 0.22% of the examined seeds.

In Brazil, programs based on elimination of infected dogs have not curtailed the spread of visceral leishmaniasis (VL), suggesting that other reservoirs of infection exist. Persons with active VL can infect the sand fly vector, but in endemic areas, persons with asymptomatic infections, whose infectivity to sand flies is unknown, are far more numerous. In this study, a polymerase chain reaction-based assay detected kinetoplast DNA of Leishmania chagasi in the blood of eight of 108 asymptomatic persons living with patients with recently diagnosed VL. These eight persons had low or unmeasurable levels of IgG antibodies to Leishmania, demonstrating the insensitivity of serology for subclinical infection. All eight persons had positive leishmanin skin test results, as did 70% of persons living in households of persons with active VL. Even if a small proportion of such asymptomatic persons are infective to sand flies, they represent a formidable reservoir of infection in endemic areas.

A elevada capacidade de adsorção de fósforo (P) é uma característica típica dos Latossolos oxídicos. O P é adsorvido principalmente por complexo de esfera interna que influencia o balanço de cargas, a dispersão de partículas e, conseqüentemente, a relação solo-água. O objetivo deste estudo foi avaliar o efeito da adsorção de P nas propriedades físicas e hídricas de amostras de um Latossolo Vermelho distrófico (LVd), da região dos Campos da Mantiqueira (MG). Amostras deformadas e indeformadas, coletadas nas camadas de 0-0,03 e 0,27-0,30 m, foram saturadas em água pura ou em solução de P, com vistas em alcançar a capacidade máxima de adsorção de fósforo (CMAP). Posteriormente, avaliaram-se alterações no teor de argila dispersa em água, índice de floculação, porosidade, limites de consistência e curva de retenção de água. A adsorção de P aumentou a quantidade de argila dispersa e influiu na quantidade de macro e microporos, acarretando aumento dos limites de consistência no deslocamento da curva de retenção de água para valores mais elevados de umidade, assim como um acréscimo dos teores de água disponível. High phosphorus (P) sorption capacity is a typical feature of oxidic oxisols. P is mainly sorbed by inner-sphere complex affecting charge balance, particle dispersion and, consequently, water-soil relationship. The objective of this study was to evaluate the effect of P sorption on physical and hydric properties of samples of a Typic Hapludox, from Campos Mantiqueira Region (Minas Gerais, Brazil). Disturbed and undisturbed soil samples, from 0-0.03 and 0.27-0.30 m depth, were saturated in pure water or P solution to reach the sorption capacity of each layer, followed by evaluation of clay dispersion, flocculation index, porosity, consistence limits, and water retention capacity. P sorption increased the content of dispersible clay and affected the amount of macro and micro pores, increasing the consistence limits and displacing the water retention curve to higher moisture values, causing an increase in available water content.

Investigations were carried out on the use of tungsten coils as electrothermal atomizers for the direct determination of low concentrations of Ba by atomic absorption spectrometry (AAS). The thermal treatment of the analytical sample was carried out in 41 s, a 10 µl sample volume being used for the determination of Ba in waters in the 10–250 pg range, with good precision (relative standard deviation < 5%). The use of hydrogen in combination with argon as purge gas was essential for the atomization of Ba. The lifetime of the coil was up to 400 firings in 0.014 mol l–1 HNO3. No interference from 8000 ng of K, 6000 ng of Na, 1000 ng of Mg, 10 ng of Ca and 10 ng of Sr were found for the atomization of 200 pg of Ba. The interference caused by larger amounts of Ca was minimized by the addition of ethylenediaminetetraacetic acid. It was shown by the paired t-test that there was no significant difference at the 5% probability level between the results obtained by tungsten coil AAS and inductively coupled plasma atomic emission spectrometry in the analysis of water samples. The detection limit was 2 pg and the characteristic mass was 3.6 pg.

1. 1. The reactivity of the sulfhydryl groups of ovalbumin has been investigated by iodine oxidation studies and by a titrimetric method with p-chloromercuribenzoate. The titrimetric method involved the addition of p-chloromercuribenzoate to solutions of the protein buffered at pH 5.3 and back titration of the excess or unreacted mercury reagent with cysteine, with nitroprusside as an outside indicator. 2. 2. The derivative of native ovalbumin and p-chloromercuribenzoate was recrystallized. It was dissociated by dialysis against excess cysteine at pH 7.0 and the original protein could be recovered. 3. 3. Native ovalbumin was found to contain approximately 3 equiv./ mole reactive sulfhydryl, and denatured ovalbumin was found to contain 4 equiv./mole. 4. 4. Partial oxidation of native ovalbumin with iodine followed by p-chloromercuribenzoate titrations indicated that iodine preferentially oxidizes those sulfhydryl groups that react with p-chloromercuribenzoate in the native protein. 5. 5. It was concluded from titrations of native and denatured whole egg white that the ovalbumin contains most, if not all, of the sulfhydryl groups in egg white.

INTRODUCTION DURING the past decade methods have been developed for the specific chemical analysis or biochemical assay of several of the egg white proteins. In the present study we have used these methods to obtain further information on the causes and mechanisms of the non-microbial deteriorations of shell eggs occurring during storage. Analytical data are presented on whites from fresh and stored eggs and on whites which were aseptically separated from fresh eggs and stored in a sterile condition. Comparative analyses on thick and thin egg white are also presented. Recent studies at this Laboratory have shown that a cause of the thinning of egg white during storage exists or arises in the egg white itself (Feeney, Silva and MacDonnell, 1950 and 1951) and that treatment of eggs with small amounts of reducing chemicals can cause changes of the white and yolk similar to the changes occurring during storage (MacDonnell, . . .

INTRODUCTION THIS report concerns the initial sources of the deteriorative agents or mechanisms which cause thinning of the white and weakening of the yolk during the storage of eggs. The experiments reported here were designed to answer the simple question whether these agents or mechanisms are inherent in the white and yolk, have their source in the yolks and diffuse into the white or vice versa, or have external sources. Previous studies have concerned attempts to identify possible deteriorative agents or mechanisms rather than to determine their sources (Sharp, 1937). Prominent among theories proposed for the thinning of white were those subscribing to an enzyme mechanism and to a chemical hydrolysis catalyzed by hydroxylions. However, the enzyme theory has been virtually discarded (Balls and Hoover, 1940; and Lineweaver et al. 1948 and 1949) and no evidence supporting chemical hydrolysis has appeared. Yolk deterioration has been associated with the passage of . . .

The expansion of sesame growth has led to one of the biggest challenges in weed management mainly due to the limited options of selective herbicides for the control of eudicots species. This study aimed to evaluate the selectivity of diuron, s-metolachlor or imazethapyr herbicide treatments in isolation, or in a tank mixture, when applied in preemergence only, or association with diuron herbicide sprayed in postemergence during sesame cultivation. Two experiments were carried out under Brazilian Cerrado conditions. In the first experiment, different doses (g ha-1) of diuron (500 and 750), s-metolachlor (480 and 960) and imazethapyr (40 and 80) were applied in preemergence in isolation or in a tank mixture. In the second experiment, doses (g ha-1) of the herbicides diuron (500 and 750) and s-metolachlor (480 and 720) were applied in preemergence isolated or in tank mixture, associated or not with diuron (500 g ha-1) in postemergence. The results indicated that diuron and s- metolachlor applied in isolation or in combination during preemergence are selective to the sesame crop up to the doses of 750 g ha-1 and 720 g ha-1, respectively, and when applied in association with diuron at a dose of 500 g ha-1 in postemergence are also selective for sesame crop. Made available in DSpace on 2022-09-20T15:06:06Z (GMT). No. of bitstreams: 1 SELECTIVITY-HERBICIDES-PREEMERGENCE-4.pdf: 579893 bytes, checksum: b641419111ea3d3cbdedb3dfa2e41944 (MD5) Previous issue date: 2021

Bacterial wilt, caused by Ralstonia solanacearum, is a major tomato disease in tropical and sub-tropical regions. It is difficult to be managed, since no single measure confers significant contribution for disease control. Among the cultural practices available for disease management, bokashi provides nutrients to the plants, increasing the microbial biomass, improving the quality of the soil and, in some cases, protecting plants against diseases. In this work, we evaluated the effect of three different bokashis (Embrapa—BE; poultry—BP and cattle—BC) in two soils artificially and naturally infested with R. solanacearum, on the suppression of bacterial wilt in tomato. Disease control is discussed upon measurements on the contents of microbial biomass carbon (MBC), on total organic carbon (TOC), on basal respiration (BR), on metabolic coefficient (qCO2) and on microbial coefficient (qMIC). The experiment was implemented in greenhouse, with completely randomized design and factorial arrangement of treatments 2 × 3 (two soils × three bokashis). Disease suppression, assessed through wilt incidence 20 and 30 days after transplanting, was better observed in the naturally infested soil, where BP and BE were more efficient in controling the disease. TOC contents were higher in the artificially infested soil compared to that naturally infested, whereas the qMIC presented higher value for the naturally infested soil, which had greater contribution of MBC. Higher rates of BR and qCO2 were observed for the naturally infested soil with BC, probably indicating high plant stress caused by the disease in this treatment. Moreover, a high and positive correlation coefficient was found between the variables qCO2 and the number of infected plants at 30 days after transplanting. In the artificially infested soil, a negative correlation was found between the number of infected plants at 20 days after transplanting and TOC.