Correlações genéticas e fenotípicas em duas populações de milho (Zea mays L.) braquítico e suas implicações no melhoramento do teor de óleo no grão

Coeficientes de correlações genéticas e fenotípicas foram estimados entre os caracteres: altura da planta (AP); altura da espiga (AE); peso de espigas (PE) e teor de óleo (TO). As estimativas foram obtidas para duas populações braquíticas de milho (Piranão VD-2 e Piranão VF-1), baseado em espiga por fileira, utilizando-se testemunha intercalar, onde a cada duas progênies plantava-se uma fileira do híbrido simples AG 305-B. Os valores das correlações genéticas aditivas encontradas entre os caracteres altura da planta, altura da espiga e peso de espigas, foram todos positivos. Para o caráter teor de óleo, quando correlacionado com os demais caracteres, os valores das correlações obtidos foram negativos nas duas populações, exceção feita ao peso de espiga correlacionada com teor de óleo, na população Piranão VD-2, cujo valor foi positivo e próximo de zero. As respostas correlacionadas obtidas entre os caracteres, quando a seleção é praticada para o caráter teor de óleo e vice versa, independente do método de seleção empregado, mostram que a seleção para teor de óleo leva a modificação na estrutura da planta, para as duas populações.

Physiological dose response of coffee (Coffea arabica L.) plants to glyphosate depends on growth stage

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Funções de pedotransferência para a curva de resistência do solo à penetração

Funções de pedotransferência são regressões utilizadas para estimar atributos edáficos dependentes a partir de atributos independentes e de fácil determinação. Nesse sentido, são propostas na literatura diversas funções de pedotransferência que visam predizer a resistência do solo à penetração. Objetivou-se, portanto, com este trabalho, desenvolver e comparar a eficiência de cinco funções de pedotransferência para a curva de resistência do solo à penetração, presentes na literatura, por meio do ajuste de dados obtidos tanto com o penetrômetro de impacto (campo) quanto com o penetrômetro eletrônico (laboratório), em um Latossolo manejado sob diferentes modos (convencional e plantio direto). Foram coletadas amostras indeformadas de solo na entrelinha das culturas, nas camadas de 0-0,10, 0,10-0,20 e 0,20-0,30 m, logo após a semeadura, no florescimento e na colheita, para determinação dos atributos físico-hídricos do solo e também da resistência do solo à penetração, com o uso do penetrômetro eletrônico. A resistência do solo à penetração, obtida com o penetrômetro de impacto, foi determinada conforme a variação do conteúdo de água no solo ao longo do ciclo das culturas. As curvas ajustadas de resistência do solo à penetração tiveram a precisão e a acurácia testadas por meio de parâmetros estatísticos e foram comparadas pelo teste F. Houve sobreposição dos valores estimados pelo ajuste das curvas, evidenciando que a maneira de obtenção da resistência do solo à penetração (campo ou laboratório) não influenciou a relação entre a resistência à penetração e os atributos do solo. As equações RP = aUg b; RP = a(1-Ug)b; RP = ae bUg e RP = a + be não diferiram e foram as mais precisas e acuradas na predição da resistência do solo à penetração.

Inhibition of the myotoxic activity of Bothrops jararacussu venom and its two major myotoxins, BthTX-I and BthTX-II, by the aqueous extract of Tabernaemontana catharinensis A. DC. (Apocynaceae)

Partial neutralization of the myotoxic effect of Bothrops jararacussu venom (BV) and two of its myotoxins [bothropstoxin-I (BthTX-I), catalytically inactive, and II (BthTX-II), showing low PLA(2) activity], by the lyophilized aqueous extract of Tabernaemontana catharinensis (AE), was studied in rat isolated soleus muscle preparations (in vitro) and through i.m. injection in the gastrocnemius muscle (in vivo) by determination of creatine kinase (CK) activity and histopathological analysis. Incubation of soleus muscle for 1 h with BV or toxins (20 mug/ml) plus AE (400 mug/ml) added immediately after BV, BthTX-I or BthTX-II reduced CK levels by 53%, 37% and 56%, respectively. The myonecrotic effects of BV (20 mug/ml) upon soleus muscle was reduced 24%, 35% and 36% when AE (400 mug/ml) was added 1 h after BV and CK was evaluated 30 min, 1 and 2 h later, respectively. For BthTX-I these values were 46%, 48% and 47%, while for BthTX-II no inhibitory effect was detected. Histological analysis of soleus muscle after incubation with AE (400 mug/ml, I h) did not reveal any change in muscle fibers, but severe necrosis induced by -BV or toxins (20 mug/ml) was clearly in evidence, and decreased significantly when soleus muscle was protected by AE. This protection was also observed when AE was administered 1 h after BV or BthTX-I, but not after BthTX-II. AE did not inhibit the catalytic PLA(2), activity of BthTX-II or BV and did not change the PAGE pattern of BV, BthTX-I or BthTX-II. In vivo assays were performed in 100-g rats and maximal CK release was attained at a dose of 100 mug of BV, 3 h after injection. AE was not effective when injected 20 s after BV or toxins. However, injecting BV or toxins (100 mug), which were pre-incubated with AE (2 mg) caused an inhibition of 57%, 59% and 51%, respectively, with zero time pre-incubation, but was less effective with I h pre-incubation. This plant represents a potential source of promising myotoxin inhibitors. (C) 2004 Elsevier GmbH. All rights reserved.

Larvicidal activity of the water extract of Moringa oleifera seeds against Aedes aegypti and its toxicity upon laboratory animals

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Seletividade de diferentes herbicidas à base de glyphosate a soja RR

Com o objetivo de avaliar a seletividade de variedades de soja transgênica (CD 214 RR e M-SOY 8008 RR) a diferentes herbicidas à base de glyphosate (Roundup Ready, Roundup Transorb, Roundup Original, Roundup WG, Polaris, Gliz, Glifosato Nortox e Trop), foi desenvolvido experimento em condições de campo, no ano agrícola 2005/2006, na Fazenda de Ensino, Pesquisa e Produção da UNESP, campus de Jaboticabal, SP. O delineamento experimental utilizado foi o de blocos ao acaso, num esquema de parcelas subdivididas, com quatro repetições. Os herbicidas foram aplicados na dose de 1,2 kg ha-1 de equivalente ácido de glyphosate, quando as plantas de soja se encontravam com a segunda folha trifoliolada totalmente expandida. Não foram observados sintomas de intoxicação dos herbicidas nas plantas de soja. Quanto às demais características avaliadas, a interação variedade x herbicida não foi significativa, indicando que os fatores comportaram-se de forma independente. Entre as variedades, as plantas de M-SOY 8008 RR apresentaram maior altura e número de nós, porém obtiveram menor produtividade de grãos que as de CD 214 RR, devido ao menor número de grãos por vagem. No tocante aos herbicidas, não houve diferença significativa entre eles, ou seja, eles não influenciaram o desenvolvimento vegetativo e reprodutivo das plantas de soja.

Glyphosate applied at low doses can stimulate plant growth

BACKGROUND: Glyphosate blocks the shikimic acid pathway, inhibiting the production of aromatic amino acids and several secondary compounds derived from these amino acids. Non-target plants can be exposed to low doses of glyphosate by herbicide drift of spray droplets and contact with treated weeds. Previous studies have reported that low doses of glyphosate stimulate growth, although these data are very limited. The objective of this study was to determine the effects of low glyphosate doses on growth of a range of plant species.RESULTS: Growth of maize, conventional soybean, Eucalyptus grandis Hill ex Maiden, Pinus caribea L. and Commelia benghalensis L. was enhanced by 1.8-36 g glyphosate ha(-1). Growth of glyphosate-resistant soybean was unaffected by any glyphosate dose from 1.8 to 720 g AE ha(-1). The optimum doses for growth stimulation were distinct for plant species and tissue evaluated. The greatest stimulation of growth was observed for C. benghalensis and P. caribea. Shikimic acid levels in tissues of glyphosate-treated soybean and maize were measured and found to be elevated at growth-stimulating doses.CONCLUSION: Subtoxic doses of glyphosate stimulate the growth of a range of plant species, as measured in several plant organs. This hormesis effect is likely to be related to the molecular target of glyphosate, since the effect was not seen in glyphosate-resistant plants, and shikimate levels were enhanced in plants with stimulated growth. (c) 2008 Society of Chemical Industry.

Avaliação de sete famílias S2 prolíficas de minimilho para a produção de híbridos

Sete famílias S2 de minimilho foram cruzadas entre si em esquema dialélico completo. Os híbridos simples obtidos foram avaliados na Estação Experimental de São Manuel, da Faculdade de Ciências Agrárias da Universidade de São Paulo (UNESP-Botucatu). O experimento foi delineado em blocos casualizados com três repetições. As parcelas consistiram de fileiras de 5 m espaçadas entre si por 0,90 m, com 50 plantas cada uma. Avaliaram-se as seguintes características: número de espigas por parcela (NE), massa de espigas com palha (MECP) e sem palha (MESP), comprimento de espigas com palha (CECP) e sem palha (CESP), diâmetro de espigas com palha (DECP) e sem palha (DESP), altura da planta (AP) e da espiga (AE). Estimaram-se os efeitos da capacidade geral e específica de combinação das famílias pelo método 4, modelo estatístico 1, proposto por Griffing. Houve predominância dos efeitos gênicos aditivos para a massa de espigas com palha e sem palha. Entretanto, para o comprimento de espigas sem palha, diâmetro de espigas com palha e sem palha, altura de planta e altura de espigas, os efeitos gênicos aditivos e não aditivos foram equivalentes. Pelas estimativas das capacidades combinatórias para o número de espigas por parcela, massa de espigas com palha e sem palha, a família 27 é a indicada para obter genótipos superiores.

Amplificação gênica alelo-específica na caracterização das hemoglobinas S, C e D e as interações entre elas e talassemias beta

INTRODUÇÃO: As hemoglobinopatias resultam de alterações hereditárias, sendo prevalentes em muitas regiões do mundo, mas atingem a população brasileira de forma significativa. Elas são decorrentes de alterações em genes estruturais responsáveis pelo aparecimento das hemoglobinas variantes e/ou em genes reguladores, resultando nas talassemias. A identificação dessas patologias tem sido rotineiramente realizada por procedimentos eletroforéticos, contudo nossa experiência laboratorial evidencia que as mesmas nem sempre apresentam resoluções suficientes para a correta caracterização da mutação. CASUÍSTICAS E MÉTODOS: O propósito deste trabalho foi estabelecer uma metodologia válida para a caracterização das hemoglobinas S, C e D em homozigose ou heterozigose, e suas possíveis interações, baseada na amplificação gênica alelo-específica (PCR-AE) com a utilização de primers sense, antisense e primers que se acoplam na posição do alelo mutante e na respectiva posição do alelo normal. RESULTADOS E DISCUSSÃO: Os resultados evidenciaram a validade dessa metodologia na caracterização das mutações, sendo esse procedimento de fácil realização, reprodutível e possível de ser aplicado em um significativo número de amostras.

In-process grinding monitoring by acoustic emission

This work aims to investigate the efficiency of digital signal processing tools of acoustic emission signals in order to detect thermal damages in grinding process. To accomplish such a goal, an experimental work was carried out for 15 runs in a surface grinding machine operating with an aluminum oxide grinding wheel and ABNT 1045. The acoustic emission signals were acquired from a fixed sensor placed on the workpiece holder. A high sampling rate data acquisition system at 2.5 MHz was used to collect the raw acoustic emission instead of root mean square value usually employed. Many statistics have shown effective to detect burn, such as the root mean square (RMS), correlation of the AE, constant false alarm (CFAR), ratio of power (ROP) and mean-value deviance (MVD). However, the CFAR, ROP, Kurtosis and correlation of the AE have been presented more sensitive than the RMS.

Surface finishing of flat pieces when submitted to lapping kinematics on abrasive disc dressed under several overlap factors

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

Algoritmos evolutivos dedicados à reconfiguração de redes radiais de distribuição sob demandas fixas e variáveis: estudo dos operadores genéticos e parâmetros de controle

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

Pancreas Transplantation Prevents Morphologic and Ultrastructural Changes in Pulmonary Parenchyma of Alloxan-Induced Diabetic Rats

Purpose. The aim of this study was to evaluate whether pancreas transplantation (PT) is a suitable method for controlling histopathologic changes in lungs of alloxan-induced diabetic rats.Methods. Sixty inbred male Lewis rats were randomly assigned to 3 experimental groups: NC, 20 nondiabetic control rats; DC, 20 untreated diabetic control rats; and PT, 20 diabetic rats that received syngeneic PT from normal donor Lewis rats. Each group was further divided into 2 subgroups of 10 rats each, which were killed after 4 and 12 weeks of follow-up. Clinical and laboratory parameters, fresh and fixed lung weights, and fixed lung volumes were recorded for all rats. Total number of alveoli, alveolar perimeter, alveolar surface area, and alveolar epithelial (AE) and endothelial capillary (EC) basal laminae thickening were randomly measured in 5 rats from each subgroup by using an image analyzer. For light microscopy, 250 alveoli were analyzed in each subgroup. For electron microscopy, 50 electron micrographs were examined for each subgroup.Results. The DC rats showed elevated blood glucose and glycosylated hemoglobin levels, with insulin blood levels significantly lower than the NC rats (P < .001). Fresh and fixed lung weights and fixed volumes were significantly reduced in these rats, although their proportions to body weight were increased at 12 weeks (P < .01). The total number of alveoli in diabetic rats was higher than in control rats, whereas alveolar perimeter and surface area were significantly diminished (P < .01). AE and EC basal laminae were significantly thicker in DC than in NC (P < .01). Successful PT corrected all clinical and metabolic changes in diabetic rats, with sustained normoglycemia throughout the study. Morphologic and morphometric changes observed in diabetic lungs were completely prevented in PT rats from 4 weeks after transplant.Conclusion. We conclude that PT can control morphologic and ultrastructural changes in pulmonary parenchyma, suggesting a promising perspective for preventing other chronic diabetic lesions.

Antigen otoxicity of Agaricus blazei mushroom organic and aqueous extracts in chromosomal aberration and cytokinesis block micronucleus assays in CHO-k1 and HTC cells

Agaricus blazei (Ab) has become popularly known for its medicinal properties. Scientifically, it has been tested with regard to its capacity to protect genetic material against damage. We examined different organic extracts (methanolic extract-ME, hexanic extract-HE and n-butanolic extract-BE) and an aqueous extract (AE) of Ab, for their capacity to induce DNA damage as well as for their protective effect. Genetic damage was determined by the chromosomal aberration assay (CA) in CHO-k1 cells for all extracts and the cytokinesis block micronucleus assay (CBMN) in non drug-metabolizing (CHO-k1) and drug-metabolizing (HTC) cell lines for extract BE only. The extracts did not show clastogenicity but showed anticlastogenicity. The greatest percent reduction obtained were with BE (105%) and AE (126%) treatments in CA. BE treatment did not display genotoxicity in CHO-k1, but was genotoxic in HTC. However, BE was shown to be antigenotoxic causing decreased micronucleus frequency in HTC and CHO-k1 cells. These results suggest that all the extracts contained protective substances, but in some cases they could show a genotoxic effect with regard to metabolism. Therefore, these findings warrant caution in the use of this mushroom by the population. (c) 2005 Elsevier Ltd. All rights reserved.

Progression of nephropathy after islet of langerhans transplantation in alloxan-induced diabetic rats

We studied the effects of islet of Langerhans transplantation (IT) on the kidney lesions of rats with alloxan-induced diabetes. Forty-five inbred male Lewis rats were randomly assigned to 3 experimental groups: group Gl included 15 non-diabetic control rats (NC), group GIT included 15 alloxan-induced diabetic rats (DC), and group III included 15 alloxan-induced diabetic rats that received pancreatic islet transplantation prepared by nonenzymatic method from normal donor Lewis rats and injected into the portal vein (IT). Each group was further divided into 3 subgroups of 5 rats which were sacrificed at 1, 3, and 6 months of follow-up, respectively. Clinical and laboratorial parameters were recorded in the mentioned periods in the 3 experimental groups. For histology, the kidneys of all rats of each subgroup were studied and 50 glomeruli and 50 tubules of each kidney were analyzed using light microscopy by two different investigators in a double blind study. The results showed progressive glomerular basement membrane thickening (GBMT), mesangial enlargement (ME), and Bowman's capsule thickening (BCT) in the 3 experimental groups throughout the follow-up. These alterations were significantly more severe in DC rats at 6 months when compared to NC rats (p < 0.01). However, the degree of GBMT, ME, and BCT observed in DC rats was not statistically different from IT rats at 1, 3, and 6 months. In addition, Armanni-Ebstein lesions of the tubules (AE) and tubular lumen protein (PRO) observed in DC rats were also observed in IT rats all over the study. These lesions were never present in NC rats. We conclude that IT did not prevent progression of kidney lesions in alloxan-induced diabetic rats within 6 months after transplantation.