1,066 research outputs found
Mapping the human lateral geniculate nucleus and its cytoarchitectonic subdivisions using quantitative MRI
International audienc
Temperature Dependence of Damping and Frequency Shifts of the Scissors Mode of a trapped Bose-Einstein Condensate
We have studied the properties of the scissors mode of a trapped
Bose-Einstein condensate of Rb atoms at finite temperature. We measured
a significant shift in the frequency of the mode below the hydrodynamic limit
and a strong dependence of the damping rate as the temperature increased. We
compared our damping rate results to recent theoretical calculations for other
observed collective modes finding a fair agreement. From the frequency
measurements we deduce the moment of inertia of the gas and show that it is
quenched below the transition point, because of the superfluid nature of the
condensed gas.Comment: 5 pages, 4 figure
Dual regulation by microRNA-200b-3p and microRNA-200b-5p in the inhibition of epithelial-to-mesenchymal transition in triple-negative breast cancer
Epithelial to mesenchymal transition (EMT) involves loss of an epithelial phenotype and activation of a mesenchymal one. Enhanced expression of genes associated with a mesenchymal transition includes ZEB1/2, TWIST, and FOXC1. miRNAs are known regulators of gene expression and altered miRNA expression is known to enhance EMT in breast cancer. Here we demonstrate that the tumor suppressive miRNA family, miR-200, is not expressed in triple negative breast cancer (TNBC) cell lines and that miR-200b-3p over-expression represses EMT, which is evident through decreased migration and increased CDH1 expression. Despite the loss of migratory capacity following re-expression of miR-200b-3p, no subsequent loss of the conventional miR-200 family targets and EMT markers ZEB1/2 was observed. Next generation RNA-sequencing analysis showed that enhanced expression of pri-miR-200b lead to ectopic expression of both miR-200b-3p and miR-200b-5p with multiple isomiRs expressed for each of these miRNAs. Furthermore, miR-200b-5p was expressed in the receptor positive, epithelial breast cancer cell lines but not in the TNBC (mesenchymal) cell lines. In addition, a compensatory mechanism for miR-200b-3p/200b-5p targeting, where both miRNAs target the RHOGDI pathway leading to non-canonical repression of EMT, was demonstrated. Collectively, these data are the first to demonstrate dual targeting by miR-200b-3p and miR-200b-5p and a previously undescribed role for microRNA processing and strand expression in EMT and TNBC, the most aggressive breast cancer subtype
Collisionless dynamics of dilute Bose gases: Role of quantum and thermal fluctuations
We study the low-energy collective oscillations of a dilute Bose gas at
finite temperature in the collisionless regime. By using a time-dependent
mean-field scheme we derive for the dynamics of the condensate and
noncondensate components a set of coupled equations, which we solve
perturbatively to second order in the interaction coupling constant. This
approach is equivalent to the finite-temperature extension of the Beliaev
approximation and includes corrections to the Gross-Pitaevskii theory due both
to quantum and thermal fluctuations. For a homogeneous system we explicitly
calculate the temperature dependence of the velocity of propagation and damping
rate of zero sound. In the case of harmonically trapped systems in the
thermodynamic limit, we calculate, as a function of temperature, the frequency
shift of the low-energy compressional and surface modes.Comment: 26 pages, RevTex, 8 ps figure
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