Desempenho de sementes de algodão tratadas quimicamente e armazenadas

Considerando que o armazenamento desempenha papel decisivo na manutenção da qualidade da semente, desenvolveu-se este trabalho com o objetivo de avaliar a qualidade fisiológica e fitossanitária de sementes de algodão, tratadas quimicamente e armazenadas por doze meses. Foram utilizados dois lotes de sementes de algodão cv. DeltaPine-AC90, deslintados quimicamente, que foram submetidos aos tratamentos fungicidas e inseticidas: testemunha; Disulfoton + Carboxin + Thiram; Carbofuran + Carboxin + Thiram; Imidacloprid + Tolylfluanid + Pencycuron. As sementes foram armazenadas em armazém sem controle de temperatura e umidade relativa do ar. Foram retiradas amostras de sementes no início do armazenamento e a cada dois meses e avaliadas quanto ao teor de água, à porcentagem de germinação, ao vigor (testes de envelhecimento acelerado e de germinação à baixa temperatura), à sanidade e à emergência das plântulas. O delineamento utilizado foi o inteiramente casualizado, em esquema fatorial, com quatro repetições. Verificou-se redução da germinação e do vigor de sementes em função do armazenamento. A redução da qualidade fisiológica associou-se com o aumento na ocorrência de Aspergillus sp. e Penicillium sp. nas sementes. A manutenção da qualidade de sementes de algodão foi obtida até o oitavo mês de armazenagem, podendo-se concluir que: a eficiência do tratamento químico de sementes de algodão depende da combinação de produtos utilizados; não se deve tratar com fungicida sementes de algodão com baixo nível de vigor; a ocorrência dos fungos Aspergillus sp. e Penicillium sp. aumentou com o período de armazenamento nas sementes sem tratamento e que a manutenção da qualidade de sementes de algodão para comercialização depende da sua qualidade inicial e do período de armazenamento.

Expression of MyoD, myogenin, myostatin and Hsp70 transcripts in chicken embryos submitted to mild cold or heat

The expression of the MyoD, myogenin, myostatin and Hsp70 genes was estimated in chicken embryos submitted to mild cold (36 +/- 0.5degreesC) or heat (44 +/- 0.5degreesC) for 1 h. 2. Marked decreases in MyoD, myogenin and myostatin transcript levels were observed in embryos exposed to high temperature, contrasting to the higher expression of the Hsp70 mRNA detected in heat-stressed embryos. 3. The exposure of chicken embryos to low temperature significantly affected only the abundance of myogenin mRNA. 4. These findings suggest that myogenic proliferation and differentiation events are compromised by variations in environmental temperature during avian embryogenesis. (C) 2003 Elsevier B.V. Ltd. All rights reserved.

Infestation of froghopper nymphs changes the amounts of total phenolics in sugarcane

The increased rate of sugarcane harvest without previous burn has provided a very favorable environment to the froghopper Mahanarva fimbriolota (Stal, 1854), with high Moisture and low temperature variation. Few works have Studied the response of sugarcane to this pest, so little is known about resistant cultivars. Plant phenolics are widely studied compounds because of their known antifierbivore effect. This research aims to determine if the attack of M.fimbriolata nymphs stimulates the acccumulation of total phenolics in sugarcane. The experiment was carried Out in greenhouse and arranged in completely randomized design, in a 3 x 2 x 4 factorial with three replications. Second instar nymphs of M. fimbriolota were infested at the following rates: control, 2-4 and 4-8 nymphs per pot (first-second infestations, respectively). Pots were covered with nylon net and monitored daily to isolate the effect of leaf Sucking adults. Leaf and root samples were collected and kept frozen in liquid nitrogen until analyses. Infested plants showed higher levels of phenolics in both root and leaf tissues. In roots, the cultivar SP80-1816 accumulated more phenolic compounds in response to the infestation of M. fimbriolata. on the other hand, higher levels were found in leaves and roots of control plants of SP86-42, which might be an indication of a non-preference mechanism. The increase of total phenolics in sugarcane infested with root-sucking froghopper nymphs does not seem to be useful to detect the resistance to this pest.

Eletrical conductivity and deterioration of soybean seeds exposed to different storage conditions

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

Electrical conductivity and mineral composition of the imbibition solution of bean seeds during storage

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

Teste de condutividade elétrica em sementes de soja armazenadas sob diferentes temperaturas

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

Cold-induced enhancement of avian uncoupling protein expression, heat production, and triiodothyronine concentrations in broiler chicks

The relationships among avian uncoupling protein (avUCP) mRNA expression, heat production, and thyroid hormone metabolism were investigated in 7-14-day-old broiler chicks (Gallus gallus) exposed to a low temperature (cold-exposed chicks, CE) or a thermoneutral temperature (TN). After 7 days of exposure, CE chicks exhibited higher heat production (+83%, P < 0.01), avUCP mRNA expression (+20%, P < 0.01), and circulating triiodothyronine (T-3) levels (+104%, P = 0.07) for non-statistically different body weights and feed intake between 3 and 7 days of exposure as compared to TN chicks. Plasma thyroxine (T-4) concentration was clearly decreased in CE chicks (-33%, P = 0.06). The lower hepatic inner-ring deiodination activity (-47%) and the higher renal outer-ring deiodination activity (+75%) measured in CE compared to TN chicks could partly account for their higher plasma T3 concentrations. This study describes for the first time the induction of avUCP mRNA expression by low temperature in chickens, as it has been previously shown in ducklings, and supports the possible involvement of avUCP in avian thermogenesis. (C) 2003 Elsevier B.V. (USA). All rights reserved.

Conservação pós-colheita de pêssego com o uso da refrigeração e da irradiação

Avaliaram-se os efeitos da irradiação ultravioleta (254nm, UV-C) na conservação de pêssegos cultivar Douradão, aos 5; 10; 15 e 20 dias de armazenamento com o uso da refrigeração (0ºc e 75-85% de uR). os tratamentos foram: controle (0 minuto de exposição - 0 kj. m -2); T1 (5 minutos -1,85 kj. m -2); T2 (10 minutos - 3,71 kj. m -2); (15 minutos - 5,55 kj. m -2), e T4 (20 minutos - 7,52 kj. m -2). o delineamento experimental foi um esquema inteiramente casualizado, com 5 tempos de armazenamento: (0; 5; 10; 15 e 20 dias), com 3 repetições e 2 frutos por unidade experimental. os parâmetros avaliados foram: sólidos solúveis (SS); acidez titulável (AT); relação SS/AT Ratio; pH; firmeza da polpa, respiração e vida útil. Os pêssegos não apresentaram alteração do pH e da At durante o tempo de armazenamento.os melhores valores de SS e firmeza da polpa foram obtidos com o tratamento T4. A taxa respiratória foi menor em T4. As alterações de SS, firmeza da polpa e respiração apresentadas pelos frutos do tratamento T4 foram menores que aquelas dos demais tratamentos, demonstrando a eficácia do uso da irradiação ultravioleta.

Armazenamento a frio de ramos porta-borbulhas e métodos de enxertia de cultivares de marmeleiro

Visando a aumentar o aproveitamento do material propagativo, ampliar o período de oferta das mudas de marmeleiro e dinamizar o uso da mão-de-obra no viveiro, faz-se necessário o armazenamento dos ramos porta-borbulhas. Sendo assim, o presente trabalho teve por objetivos estudar a viabilidade da manutenção dos ramos porta-borbulhas de diferentes cultivares de marmeleiro, por meio do armazenamento a frio, e diagnosticar o método de enxertia para promover melhor desenvolvimento do enxerto. Ramos dos marmeleiros 'Japonês' (Chaenomeles sinensis), 'Smyrna', 'Portugal', 'Mendoza Inta-37' e 'Provence' (Cydonia oblonga) foram coletados em julho de 2008. Uma parte dos ramos foi utilizada para a realização da enxertia (métodos de borbulhia e garfagem) em mudas de seis meses de idade do porta-enxerto 'Japonês', e a outra parte foi armazenada sob baixa temperatura (estacas envoltas em papel umedecido, embrulhadas em sacos de polietileno colocadas em câmara fria a 4°C), por 30 e 60 dias. Passados 60 dias, foi mensurada a porcentagem de brotação dos enxertos e, ao final de 120 dias da realização das enxertias, foram mensurados o comprimento, o diâmetro e a massa seca média dos enxertos. Concluiu-se que, apesar de as cultivares apresentarem diferença, recomenda-se que os ramos sejam armazenados por até 30 dias, sendo utilizada a enxertia pelo método de garfagem.

Thermochronology of the South American platform in the state of São Paulo, Brazil, through apatite fission tracks

The fission-track method (FTM) in apatite was applied to 45 samples collected in the Serra da Mantiqueira (Mantiqueira mountain range), the Serra do Mar (Mar mountain range), regions next to these mountain ranges and the coastal region between Ubatuba and Santos in the State of São Paulo, Brazil, to study the thermochronology of the South American Platform in southeast Brazil and its influence on Santos and Campos basins. The data presented in this work complement the previously presented data on the same region (Tello Saenz et al., 2003. J. S. Am. Earth Sci. 15, 765-774) with 31 new samples analyzed. The weighted mean of the corrected ages from high Mantiqueira (around 1000 m), (121 +/- 6) Ma, coincides with the South Atlantic opening. The fact that its thermal history starts at a relatively low temperature (similar to 80 degrees C) suggests that the age of similar to 120 Ma would be the formation age of Serra da Mantiqueira due to a rapid pulse, in which tracks had no time to be retained at the closure temperature, that is similar to 120 degrees C. The Serra do Mar presents a more complicated thermal history, with several reactivations indicated by the changes in the slope of its cooling curve. The thermal histories obtained in the regions next to these mountain ranges are compatible with the results mentioned above. The Santos Basin has unconformities that agree with changes in the slope thermal histories of the studied region. (c) 2005 Elsevier Ltd. All rights reserved.

Surface Modification of Polycarbonate by Atmospheric-Pressure Plasma Jets

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

Crystallization kinetics in phosphate sodium-based glass studied by DSC technique

In this work, differential scanning calorimetry (DSC) was used to study the mechanism of crystallization of 5OP(2)O(5-)27.8Na(2)O-16ZnO-6.2Al(2)O(3) glass. DSC measurements were performed on bulk and powdered glasses with different particle size. The curve for bulk glass shows one crystallization peak while powdered glasses presented two distinct crystallization peaks. Based on DSC studies, the activation energies obtained were 336 +/- 6 and 213 +/- 3 U mol(-1), associated with first and second crystallization peaks, respectively. Analyzing the DSC parameters as a function of particle size, the Avrami n parameter suggests that the peak at low temperature may be associated with surface crystallization while the peak at high temperature is associated with bulk crystallization. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

Thermoluminescence of aluminophosphate glasses in the metaphosphate composition

Potassium aluminum phosphate (KAP) glasses in the system xKPO(3)-(100-x)AI(PO3)3 with x = 10, 30 and 50 mol% were prepared in the metaphosphate composition. The glasses were doped with MnO2 and their thermoluminescent (TL) response was investigated. Raman spectra showed that these glasses did not undergo structural changes with the substitution of manganese ions. The glass composition x = 50 mol% doped with 1.0 mol% of MnO2 presented the best TL response. The material displayed good sensitivity for gamma-rays, X-rays and UV light. The emission curves exhibited two TL peaks, one at a low temperature (similar to 150 degrees C) and the other at a high temperature (similar to 365 degrees C), whose positions were dependent on the type of exciting radiation applied. The results of the present study indicated that the high temperature peak is a good candidate for TL dosimetric investigations. (c) 2006 Elsevier B.V. All rights reserved.

Effect of polyol excess on the electrical property of vegetable-polyurethane film

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

An Oligosilsesquioxane Cage Functionalized with Molybdenum(II) Organometallic Fragments

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