These findings form a proof-of-concept that continuous attractor dynamics may underlie velocity integration in the dorsolateral medial entorhinal cortex. The simulations also generate pertinent upper bounds on the accuracy of integration that may be achieved

by continuous attractor dynamics in the grid cell network. We suggest experiments to test the continuous attractor model and differentiate it from models in which single cells establish their responses independently of each other.”
“MicroRNAs (miRNAs) are non-coding small RNAs that regulate gene expression by translational repression or transcript degradation. A large number of miRNAs have been identified from model plant species; however, the character of conserved miRNAs is poorly understood. We studied 42 miRNA families that are conserved within the plant kingdom, using the Selleck Autophagy Compound Library miRBase database. Some conserved miRNA families were found to be preferentially expressed in dicots relative to monocots, Selleck HIF inhibitor especially miR403, miR472 and miR479. Using an improved homology search-based approach

and the conserved miRNAs as the query set, 34 conserved miRNAs and the miR482 family were identified in wheat. Forty-six wheat mRNAs were predicted as their putative target genes. Most conserved wheat miRNAs were found to retain homologous target interactions and have analogous molecular functions. The miR172 displayed a wheat-specific function and was found to have an additional target interaction with succinyl-CoA ligase. We concluded that although miRNAs are conserved, the expression and function of some have drifted during long periods

of plant evolution.”
“Polarization characteristics of the near-band-edge optical transitions in m-plane AlxGa1-xN epilayers suffering from anisotropic stresses were quantified. The epilayers were grown by both ammonia-source molecular beam epitaxy and metalorganic vapor phase epitaxy methods on an m-plane freestanding GaN substrate. The light polarization direction altered from E perpendicular to c to E<parallel to>c at the AlN molar fraction, x, between 0.25 and 0.32, where E is the electric field component of the light and perpendicular to and <parallel to> represent perpendicular and parallel, respectively. To give a quantitative explanation for the result, energies and oscillator strengths of the exciton transitions involving three separate valence bands were calculated as functions selleck of strains using the Bir-Pikus Hamiltonian. The calculation predicted that the lowest energy transition (E-1) is polarized to the m-axis normal to the surface (X-3) for 0 < x < 1, meaning that E-1 emission is principally undetectable from the surface normal for any in-plane tensile strained AlxGa1-xN. The polarization direction of observable surface emission was predicted to alter from c-axis normal (X-1) to c-axis parallel (X-2) for the middle energy transition (E-2) and X-2 to X-1 for the highest energy transition (E-3) between x=0.25 and 0.32.