331 research outputs found
Controlling Lethal Browning of \u3cem\u3eHemarthria compressa\u3c/em\u3e Tissue Cultures
Hemarthria compressa is an important warm-season forage grass for use in Southwest China. However, due to poor seed set, it is propagated by vegetative cuttings of stolons, rhizomes, and nodal sections. The in vitro propagation of H. compressa is still faced with difficulties including blackening or browning of tissues prior to culturing due to the oxidation of phenolic compounds by polyphenolic oxidase enzyme present in excised tissue (Yang et al. 2008). The objectives of the study were to investigate possible means of successful initiation of cultures through elimination of phenolic browning
MicroRNA410 Inhibits Pulmonary Vascular Remodeling via Regulation of Nicotinamide Phosphoribosyltransferase
Nicotinamide phosphoribosyltransferase (NAMPT) upregulation in human pulmonary artery endothelial cells (hPAECs) is associated with pulmonary arterial hypertension (PAH) progression and pulmonary vascular remodeling. The underlying mechanisms regulating NAMPT expression are still not clear. In this study, we aimed to study the regulation of NAMPT expression by microRNA410 (miR410) in hPAECs and explore the role of miR410 in the pathogenesis of experimental pulmonary hypertension. We show that miR410 targets the 3' UTR of NAMPT and that, concomitant with NAMPT upregulation, miR410 is downregulated in lungs of mice exposed to hypoxia-induced pulmonary hypertension (HPH). Our results also demonstrate that miR410 directly inhibits NAMPT expression. Overexpression of miR410 in hPAECs inhibits basal and VEGF-induced proliferation, migration and promotes apoptosis of hPAECs, while miR410 inhibition via antagomirs has the opposite effect. Finally, administration of miR410 mimics in vivo attenuated induction of NAMPT in PAECs and prevented the development of HPH in mice. Our results highlight the role of miR410 in the regulation of NAMPT expression in hPAECs and show that miR410 plays a potential role in PAH pathobiology by targeting a modulator of pulmonary vascular remodeling
Measuring cosmogenic Li9 background in a reactor neutrino experiment
Cosmogenic isotopes 9Li and 8He produced in the detector are the most
problematic background in the reactor neutrino experiments designed to
determine precisely the neutrino mixing angle theta13. The average time
interval of cosmic-ray muons in the detector is often on the order of the
lifetimes of the 9Li and 8He isotopes. We have developed a method for
determining this kind of background from the distribution of time since last
muon for muon rate up to about 20 Hz when the background-to-signal ratio is
small, on the order of a few percents.Comment: 9 pages, 3 figures. To appear in NIM
NeighViz: Towards Better Understanding of Neighborhood Effects on Social Groups with Spatial Data
Understanding how local environments influence individual behaviors, such as
voting patterns or suicidal tendencies, is crucial in social science to reveal
and reduce spatial disparities and promote social well-being. With the
increasing availability of large-scale individual-level census data, new
analytical opportunities arise for social scientists to explore human behaviors
(e.g., political engagement) among social groups at a fine-grained level.
However, traditional statistical methods mostly focus on global, aggregated
spatial correlations, which are limited to understanding and comparing the
impact of local environments (e.g., neighborhoods) on human behaviors among
social groups. In this study, we introduce a new analytical framework for
analyzing multi-variate neighborhood effects between social groups. We then
propose NeighVi, an interactive visual analytics system that helps social
scientists explore, understand, and verify the influence of neighborhood
effects on human behaviors. Finally, we use a case study to illustrate the
effectiveness and usability of our system.Comment: Symposium on Visualization in Data Science (VDS) at IEEE VIS 202
Optimizing Flow Control with Deep Reinforcement Learning: Plasma Actuator Placement around a Square Cylinder
The present study proposes an active flow control (AFC) approach based on
deep reinforcement learning (DRL) to optimize the performance of multiple
plasma actuators on a square cylinder. The investigation aims to modify the
control inputs of the plasma actuators to reduce the drag and lift forces
affecting the cylinder while maintaining a stable flow regime. The environment
of the proposed model is represented by a two-dimensional direct numerical
simulation (DNS) of a flow past a square cylinder. The control strategy is
based on the regulation of the supplied alternating current (AC) voltage at
three distinct configurations of the plasma actuators. The effectiveness of the
designed strategy is first investigated for Reynolds number, ,
and further applied for . The applied active flow control
strategy is able to reduce the mean drag coefficient by 97\% at
and by 99\% at . Furthermore, the results from this study show that
with the increase in Reynolds number, it becomes more challenging to eliminate
vortex shedding with plasma actuators located only on the rear surface of the
cylinder. Nevertheless, the proposed control scheme is able to completely
suppress it with an optimized configuration of the plasma actuators.Comment: 30 pages, 17 figure
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