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

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

Supersymmetry and Integrability in Planar Mechanical Systems

We present an N=2-supersymmetric mechanical system whose bosonic sector, with two degrees of freedom, stems from the reduction of an SU(2) Yang-Mills theory with the assumption of spatially homogeneous field configurations and a particular ansatz imposed on the gauge potentials in the dimensional reduction procedure. The Painleve test is adopted to discuss integrability and we focus on the role of supersymmetry and parity invariance in two space dimensions for the attainment of integrable or chaotic models. Our conclusion is that the relationships among the parameters imposed by supersymmetry seem to drastically reduce the number of possibilities for integrable interaction potentials of the mechanical system under consideration.Comment: 20 pages, 3 figure