116 research outputs found

    Agronomic efficiency of granulated organomineral fertilizers based on poultry litter and phosphates.

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    This paper has as aim to evaluate the agronomic efficiency of granulated organomineral fertilizers produced from poultry litter and mineral sources of phosphorus

    AlteraçÔes em atributos do solo decorrentes da aplicação de nitrogĂȘnio e palha em sistema semeadura direta na cultura do milho.

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    Nos Ășltimos anos, tem-se procurado elevar os teores de C orgĂąnico do solo e, ao mesmo tempo, aumentar a produtividade das culturas. Neste contexto, o sistema semeadura direta (SSD) tem importante participação, principalmente na regiĂŁo dos Cerrados. Entretanto, para se alcançar altas produtividades, as gramĂ­neas requerem a adição de doses elevadas de adubos nitrogenados. Este trabalho teve por objetivo avaliar as alteraçÔes no solo decorrentes da aplicação de palha e de N em solo cultivado com milho por 10 anos (1991-2001) em SSD. O experimento foi desenvolvido na Embrapa-Milho e Sorgo, em Sete Lagoas-MG, em um Latossolo Vermelho distrĂłfico tĂ­pico sob cerrado. Os tratamentos constaram da combinação de palha sobre o solo (0, 3, 6, 9 e 12Mg ha-1 de matĂ©ria seca) dispostas nas parcelas, e de cinco nĂ­veis de N aplicados em cobertura (0, 40, 80, 120 e 160kg ha-1), na forma de urĂ©ia, dispostos nas subparcelas. Foram realizadas duas coletas de solo (antes e apĂłs uma calagem), nas profundidades de 0-0,025; 0,025-0,05; 0,05-0,10; 0,10-0,20; 0,20-0,40m. AnĂĄlises quĂ­micas e fĂ­sicas de rotina foram efetuadas usando-se mĂ©todos padrĂ”es. Os teores de C orgĂąnico e de K foram influenciados pelas doses de palha e aumentaram Ă  medida que se aumentou a aplicação de palha sobre o solo. A variação nas doses de N promoveu alteraçÔes no pH, nos teores de Ca, Mg e nas saturaçÔes por bases e por Al atĂ© a profundidade de 0,20m. A calagem superficial promoveu o aumento do pH do solo em profundidade e dos teores de Ca, atĂ© 0,20m, provavelmente devido Ă  alta pluviosidade no perĂ­odo pĂłs-calagem (1600mm em oito meses)

    Doses de nitrogĂȘnio e de palha em sistema plantio direto de milho no cerrado.

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    O objetivo do trabalho foi avaliar, em campo, o teor foliar e a produtividade de milho (Zea mays L.) em um Latossolo Vermelho distrĂłfico tĂ­pico do cerrado, influenciados por doses de palha e de N. O experimento foi desenvolvido em Sete Lagoas-MG. Os tratamentos empregados foram cinco doses de palha de milho em cobertura na parcela principal (O, 3, 6, 9 e 12 t ha -1) e cinco doses de N na subparcela (O, 40, 80, 120 e 160 kg N ha. -1), na forma de urĂ©ia em cobertura, os quais vĂȘm sendo aplicados anualmente por dez anos. No dĂ©cimo ano, foram avaliados o estado nutricional e a produtividade do milho. As doses de palha nĂŁo afetaram significativamente o estado nutricional e o rendimento de grĂŁos de milho. Os resultados indicaram que o incremento de doses de N aplicadas em cobertura possibilita aumento da absorção de N, P, S, Cu, Fe e Zn pela planta. A produtividade da cultura do milho foi positivamente influenciada pela adubação nitrogenada, encontrando a mĂĄxima eficiĂȘncia agronĂŽmica para a dose 140 kg N ha -1 na forma de urĂ©ia, com produtividade de cerca de 11 t ha -1

    Modulating MIOX2 expression in Nicotiana tabacum and impacts on genes involved in cell wall biosynthesis

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    Cell walls are essential structures for plant development and growth. Apart from its biological functions, the polysaccharides that make cell walls (cellulose, hemicellulose and pectins) are the principal natural fibrous materials, considered the most important renewable resource on earth, used as raw material for many industrial processes among them, for pulp and paper production, charcoal, and biofuels. For all these reasons, the study of molecular composition and biosynthesis of plant cell walls has been a matter of great interest for researchers over the past few years. In this context, a full-length cDNA fragment of Miox2 gene was cloned from Arabidopsis seedlings, using RT-PCR, with an open reading frame of 954 pb and a corresponding protein subunit molecular mass of 37 kDa. The deduced amino acid sequence of the cDNA showed a high degree of homology with myo-Inosytol oxygenases from other organisms. This cDNA was used for genetic transformation of model plants (tobacco), which expressed either antisense or sense RNA. Transgenic homozygous tobacco model plants with either repression or constitutively expressed Miox2 were obtained with the number of copies varying from 1 to 7. Neither, the repression of the endogenous tobacco Miox genes or the constitutive expression of Miox2 gene, caused major impact on plant development, leaf morphology or flowering time. There was however, statistically significant (P<0.05) changes in the arabinan and D-galacturonate contents. These results clearly indicate that the modulation of the myo-Inositol pathway caused no major impact on cell wall polysaccharide biosynthesis.As paredes celulares vegetais sĂŁo estruturas essenciais para o crescimento e desenvolvimento das plantas. AlĂ©m de suas diversas funçÔes biolĂłgicas, os componentes polissacarĂ­dicos constituintes das paredes celulares (celulose, hemiceluloses e pectinas) sĂŁo de vital importĂąncia como fonte natural de fibras, sendo consideradas as fontes principais de recursos renovĂĄveis do planeta, utilizados como matĂ©ria prima para diversos processos industriais, dentre eles, a produção de papel e celulose, carvĂŁo vegetal e biocombustĂ­veis. Todos esses fatores tĂȘm despertado grande interesse no estudo da composição e biossĂ­ntese das paredes celulares. Neste contexto, um fragmento de cDNA do gene Miox2 foi clonado de plĂąntulas de Arabidopsis, via RT-PCR, com uma regiĂŁo aberta de leitura de 954 pb e sua proteĂ­na com massa molecular de 37kDa. A sequĂȘncia deduzida de aminoĂĄcidos do cDNA apresentou alto grau de identidade com mio-Inositol oxigenases de outros organismos. Este cDNA foi usado para transformação genĂ©tica de plantas modelo (tabaco) que produziram RNA antisense ou sense. Plantas de tabaco homozigotas para o transgene com repressĂŁo ou expressĂŁo constitutiva do gene Miox2 foram obtidas com um nĂșmero de cĂłpias do transgene, variando de 1 a 7. A repressĂŁo do gene Miox de tabaco endĂłgeno assim como a expressĂŁo constitutiva do gene Miox2 de Arabidopsis nĂŁo causaram alteraçÔes no desenvolvimento, morfologia foliar ou tempo de florescimento das plantas. Entretanto, alteraçÔes estatisticamente significativas (P<0.05) ocorreram no conteĂșdo de arabinana e de D-galacturonato. Estes resultados indicam que a modulação do metabolismo do mio-Inositol nĂŁo causou grandes impactos na biossĂ­ntese dos polissacarĂ­deos da parede celular.Fil: DefĂĄvari Nascimento, D.. Universidade do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; BrasilFil: Conti, Gabriela. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; ArgentinaFil: Labate, MĂŽnica T. V.. Universidade do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; BrasilFil: Gutmanis, Gunta. Universidade do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; BrasilFil: Bertolo, Ana L. F.. Universidade do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; BrasilFil: de Andrade, Alexander. Universidade do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; BrasilFil: Bragatto, Juliano. Universidade do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; BrasilFil: Pagotto, LuĂ­s OtĂĄvio. Universidade do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; BrasilFil: Damin, PlĂ­nio. Universidade do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; BrasilFil: Moon, David H.. Universidade do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; BrasilFil: Labate, Carlos A.. Universidade do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; Brasi

    Identification of human papillomavirus DNA gene sequences in human breast cancer

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    Human papilloma viruses (HPVs) are accepted as being carcinogenic in human cervical and anogenital cancers. The suspicion that HPVs may also have a role in human breast cancer is based on the identification of HPVs in human breast tumours and the immortalisation of normal human breast cells by HPV types 16 and 18. For this investigation, DNA that had been previously extracted and fresh frozen at −70°C from 50 unselected invasive ductal breast cancer specimens were screened by polymerase chain reaction (PCR) for HPV type 16, 18 and 33 gene sequences. We show that HPV 18 gene sequences are present in DNA extracted from breast tumours in Australian women. Overall, 24 (48%) of the 50 samples were HPV positive. Overall no correlations with tumour grade, patient survival, steroid receptor status, ERB-2, p53 expression and mutation were observed. Human papilloma viruses may have a role in human breast cancer. We speculate that HPVs may be transmitted by hand from the female perineum to the breast

    High-risk human papillomavirus infections in breast cancer in Syrian women and their association with Id-1 expression: a tissue microarray study

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    High-risk human papillomaviruses (HPVs) could be important risk factors for breast carcinogenesis and metastasis. Based on this hypothesis, we recently studied the effect of E6/E7 onco-proteins of high-risk HPV type 16 in two non-invasive human breast cancer cell lines, BT20 and MCF7; we reported that E6/E7 converts these cell lines to invasive cells. This is accompanied by an overexpression of Id-1, which is an important regulator of breast metastasis. In this investigation, we examined the presence of high-risk HPVs (16, 18, 31, 33 and 35) and the expression of their E6 onco-protein as well as their correlation with Id-1 gene expression, using polymerase chain reaction (PCR) and tissue microarray (TMA) analysis, respectively, in a cohort of 113 Syrian breast cancer patients. We found that high-risk HPV types 16, 18, 31, 33 and 35 are present in 8.84, 9.73, 7.07, 55.75 and 37.16% of our samples, respectively, which represent invasive breast cancers. Overall, 69 (61.06%) of the 113 samples are HPV positive; among these specimens 24 tissues (34.78%) are coinfected with more than one HPV type. Furthermore, we report that the expression of the E6 onco-protein of these high-risk HPVs is correlated with Id-1 overexpression in the majority of invasive breast cancer tissue samples. Our data suggest that high-risk HPV infections are associated with human breast cancer progression in Syrian women

    Post-Mortem diagnosis of dementia by informant interview

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    Abstract The diagnosis of normal cognition or dementia in the Brazilian Brain Bank of the Aging Brain Study Group (BBBABSG) has relied on postmortem interview with an informant. Objectives: To ascertain the sensitivity and specificity of postmortem diagnosis based on informant interview compared against the diagnosis established at a memory clinic. Methods: A prospective study was conducted at the BBBABSG and at the Reference Center for Cognitive Disorders (RCCD), a specialized memory clinic of the Hospital das ClĂ­nicas, University of SĂŁo Paulo Medical School. Control subjects and cognitively impaired subjects were referred from the Hospital das ClĂ­nicas to the RCCD where subjects and their informants were assessed. The same informant was then interviewed at the BBBABSG. Specialists' panel consensus, in each group, determined the final diagnosis of the case, blind to other center's diagnosis. Data was compared for frequency of diagnostic equivalence. For this study, the diagnosis established at the RCCD was accepted as the gold standard. Sensitivity and specificity were computed. Results: Ninety individuals were included, 45 with dementia and 45 without dementia (26 cognitively normal and 19 cognitively impaired but non-demented). The informant interview at the BBBABSG had a sensitivity of 86.6% and specificity of 84.4% for the diagnosis of dementia, and a sensitivity of 65.3% and specificity of 93.7% for the diagnosis of normal cognition. Conclusions: The informant interview used at the BBBABSG has a high specificity and sensitivity for the diagnosis of dementia as well as a high specificity for the diagnosis of normal cognition
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