645 research outputs found
Spin-phonon coupling in Gd(Co1/2Mn1/2)O3 perovskite
We have investigated the temperature-dependent Raman-active phonons and the
magnetic properties of Gd(Co1/2Mn1/2)O3 perovskite ceramics in the temperature
range from 40 K to 300 K. The samples crystallized in an orthorhombic distorted
simple perovskite, whose symmetry belongs to the Pnma space group. The data
reveals spin-phonon coupling near the ferromagnetic transition occurring at
around 120 K. The correlation of the Raman and magnetization data suggests that
the structural order influences the magnitude of the spin-phonon coupling.Comment: 3 Figures, suplementary materia
Prediction of potential novel microRNAs in soybean when in symbiosis.
MicroRNAs (miRNAs) are small molecules, noncoding proteins that are involved in many biological processes, especially in plants; among these processes is nodulation in the legume. Biological nitrogen fixation is a key process, with critical importance to the soybean crop. This study aimed to identify the potential of novel miRNAs to act during the root nodulation process. We utilized a set of transcripts that were differentially expressed in soybean roots 10 days after inoculation with Bradyrhizobium japonicum, which were obtained in a previous study, and performed a set of computational analyses that led us to select new miRNAs potentially involved in nodulation. Among these analyses, the set of transcripts were submitted to an in silico annotation of noncoding RNAs, including a search of similarity against miRNA public databases, ab initio tools for miRNA identification, structural search against miRNA families, prediction of the secondary structure of miRNA precursors, and prediction of the sequences of mature miRNAs. Subsequently, we applied filter procedures based on miRNA selections described in the literature (e.g., free energy value). In the next step, a manual curation inspection of the annotation was performed and the top candidates were selected and used for prediction of potential target genes, which were later checked manually in the database of the soybean genome. This prediction led us to the identification of 9 potential new miRNAs; among these, 4 were conserved in other plants. Moreover, we predicted their target genes might play important roles in the regulation of nodulation
Teor de vitamina A e caroteno em manteigas consumidas em São Paulo
The main scope of this work was that of the determination of the carotene and vitamin A of the butter produced and consumed in the State of S. Paulo (Brazil). In spite of having at hand samples from the majority of the producing areas, we could not obtain samples from all sources at regular intervals during the whole period of study. From some producing areas the samples were in a very limited number. Thus, the statistical analysis of the results became unpracticable and, consequently, from these results we cannot get the necessary statistical inference. The A.A. analysed 189 samples of the butter produced mostly in the State of S. Paulo in the period of June, 1954 to May, 1955 and consumed in the Capital of S. Paulo. The extraction was done according to the method suggested by McDowell and the colorimetric determination using the Carr-Price reagent. The optical density was measured in a Coleman Junior Spectrophotometer, model 6-A, at 620 milimicra for the vitamin A and at 440 milimicra for the carotene determination. Aiming to make the discount of the color developed due to the xantophyles, the A.A. analysed 20% of the samples through the Berl-Peterson method, in which some modifications were introduced. The results showed that an average of 14% of the color was due to the xantophyles and, because of this and in this basis, a correction of the carotene values was done. Under the conditions the work was run, the A.A. were led to conclude: 1) The annual average of the analyses of the 189 samples of the butter consumed in the Capital of S. Paulo and produced mostly in the State of S. Paulo, in the period of June, 1954 to May, 1955, was of 6.2 carotene microgrammes, 28.7 U.I. of vitamin A and 39.1 U.I. of total vitamin A potency per gramme of butter fat. 2) The carotene maximum value was observed in February (11 microgrammes) and the minimum in October (3.1 microgrammes). The vitamin A maximum content was registered in October (40.2 U.I.) and the minimum in December (20.0 U.I.). The total vitamin A maximum content was seen in October (45.9 U.I.) and the minimum in March (34.4 U.I.). 3) The total vitamin A potency is higher in the winter and lower in the summer. 4) The maximum values registered for total vitamin A potency coincided with the minimum rainfall in the studied areas, not counting October value.O objetivo deste trabalho era o de determinar o teor em caroteno e em vitamina A da manteiga produzida e consumida no Estado de São Paulo (Brasil). O fato de não ter sido possÃvel receber amostras da totalidade das fontes produtoras do Estado, a par da irregularidade com que nos foram remetidas, de modo geral, e mesmo a insuficiência numérica no caso de algumas procedências, impediram a obtenção de elementos seguros para uma inferência estatÃstica. Os A.A. analisaram 189 amostras de manteiga produzida, a maior parte no Estado de São Paulo, no periodo de junho de 1954 a maio de1955 e tôda consumida na Capital de São Paulo, valendo-se do método de extração preconizado por McDowell e determinação colorimétrica pelo reagente de Carr-Price. As leituras, em espectrofotômetro Coleman Junior, modêlo 6-A, foram feitas a 620 milimicra para a vitamina A e a 440 milimicra para o caroteno. Com a finalidade de proceder ao desconto da côr desenvolvida pelas xantofilas, os A.A. analisaram 20% das amostras pelo método de Berl-Peterson, a que introduziram algumas modificações. Os resultados atribuÃram, em média, 14% da côr como sendo devido à s xantofilas e, por isso, nessa base foi realizada a correção para os valores de caroteno. Nas condições em que se realizou o trabalho os A.A. concluem: 1) A média anual das análises de 189 amostras de manteiga consumida na Capital de São Paulo e produzida a maior parte no Estado de São Paulo, no perÃodo de junho de 1954 a maio de 1955, foi de 6,2 microgramas de caroteno, 28,7 U.I. de vitamina A e 39,1 U.I. de vitamina A total por grama de gordura de manteiga. 2) Para caroteno o teor máximo foi observado em fevereiro (11 μ g/g) e o mÃnimo em outubro (3,1 μ g/g). Para a vitamina Ao conteúdo máximo foi verificado em outubro (40,2 U.I.) e o mÃnimo em dezembro (20,0 U.I.). Para a vitamina A total o valor máximo foi registrado em outubro (45,9 U.I.) e o mÃnimo em março (34,4 U.I.).  3) Os valores encontrados para a vitamina A total foram mais altos no inverno e primavera e mais baixos no verão e outono. 4) Os valores máximos registrados para a vitamina A total coincidiram com a menor queda pluviométrica na região estudada, exceção do mês de outubro
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