Quantum effects in linear and non-linear transport of T-shaped ballistic junction

We report low-temperature transport measurements of three-terminal T-shaped device patterned from GaAs/AlGaAs heterostructure. We demonstrate the mode branching and bend resistance effects predicted by numerical modeling for linear conductance data. We show also that the backscattering at the junction area depends on the wave function parity. We find evidence that in a non-linear transport regime the voltage of floating electrode always increases as a function of push-pull polarization. Such anomalous effect occurs for the symmetric device, provided the applied voltage is less than the Fermi energy in equilibrium

Bases expert statement on the use of music for movement among people with Parkinson's

First published in The Sport and Exercise Scientist, February 2020, Issue 63. Published by the British Association of Sport and Exercise Sciences – www.bases.org.uk.Music is an artistic auditory stimulus that unfolds over time. It can prime specific actions and prompt engagement in physical activity as well as heighten motivation during motor tasks (Karageorghis, 2020). Contrastingly, it can be used to downregulate arousal to facilitate the transition from an active to a sedentary state or to ameliorate anxiety. In therapeutic applications, musical features such as rhythm, melody and harmony have been shown to elicit psychological and physiological changes (Thaut & Hoemberg, 2014). Parkinson’s is a degenerative neurological condition in which the loss of dopamine neurons results in impaired initiation and control of movement, with common symptoms including tremor, postural instability and gait disturbance. There are also non-motor effects that include apathy, anxiety and depression. Medication does not alleviate all manifestations of the condition and there is presently no known cure (Obeso et al., 2017). It is notable that people with Parkinson’s are estimated to be 30% less active than agematched peers (Ramaswamy et al., 2018). Nonetheless, evidence is emerging that a range of exercise-based and social activities that involve musical engagement can serve to address the common symptoms and enhance quality of life (Thaut & Hoemberg, 2014). This statement brings together an international interdisciplinary team to outline what is known about music-related applications for people with Parkinson’s, and to provide recommendations for exercise and health practitioners.Peer reviewe

Understanding the plasmonic properties of dewetting formed Ag nanoparticles for large area solar cell applications

Cataloged from PDF version of article.The effects of substrates with technological interest for solar cell industry are examined on the plasmonic properties of Ag nanoparticles fabricated by dewetting technique. Both surface matching (boundary element) and propagator (finite difference time domain) methods are used in numerical simulations to describe plasmonic properties and to interpret experimental data. The uncertainty on the locations of nanoparticles by the substrate in experiment is explained by the simulations of various Ag nanoparticle configurations. The change in plasmon resonance due to the location of nanoparticles with respect to the substrate, interactions among them, their shapes, and sizes as well as dielectric properties of substrate are discussed theoretically and implications of these for the experiment are deliberated. (C) 2013 Optical Society of Americ

Photometric and spectroscopic evolution of the IIP SN 2007it to day 944

SN 2007it is a bright, Type IIP supernova which shows indications of both pre-existing and newly formed dust. The visible photometry shows a bright late-time luminosity, powered by the 0.09 M ☉ of 56Ni present in the ejecta. There is also a sudden drop in optical brightness after day 339, and a corresponding brightening in the IR due to new dust forming in the ejecta. CO and SiO emission, generally thought to be precursors to dust formation, may have been detected in the mid-IR photometry of SN 2007it. The optical spectra show stronger than average [O I] emission lines and weaker than average [Ca II] lines, which may indicate a 16-27 M ☉ progenitor, on the higher end of expected Type IIP masses. Multi-component [O I] lines are also seen in the optical spectra, most likely caused by an asymmetric blob or a torus of oxygen core material being ejected during the SN explosion. Interaction with circumstellar material prior to day 540 may have created a cool dense shell between the forward and reverse shocks where new dust is condensing. At late times there is also a flattening of the visible light curve as the ejecta luminosity fades and a surrounding light echo becomes visible. Radiative transfer models of SN 2007it spectral energy distributions indicate that up to 10–4 M ☉ of new dust has formed in the ejecta, which is consistent with the amount of dust formed in other core-collapse supernovae

Admixture mapping scans identify a locus affecting retinal vascular caliber in hypertensive African Americans: the Atherosclerosis Risk in Communities (ARIC) study. PLoS Genet.

Abstract Retinal vascular caliber provides information about the structure and health of the microvascular system and is associated with cardiovascular and cerebrovascular diseases. Compared to European Americans, African Americans tend to have wider retinal arteriolar and venular caliber, even after controlling for cardiovascular risk factors. This has suggested the hypothesis that differences in genetic background may contribute to racial/ethnic differences in retinal vascular caliber. Using 1,365 ancestry-informative SNPs, we estimated the percentage of African ancestry (PAA) and conducted genome-wide admixture mapping scans in 1,737 African Americans from the Atherosclerosis Risk in Communities (ARIC) study. Central retinal artery equivalent (CRAE) and central retinal vein equivalent (CRVE) representing summary measures of retinal arteriolar and venular caliber, respectively, were measured from retinal photographs. PAA was significantly correlated with CRVE (r = 0.071, P = 0.003), but not CRAE (r = 0.032, P = 0.182). Using admixture mapping, we did not detect significant admixture association with either CRAE (genome-wide score = 20.73) or CRVE (genome-wide score = 20.69). An a priori subgroup analysis among hypertensive individuals detected a genome-wide significant association of CRVE with greater African ancestry at chromosome 6p21.1 (genome-wide score = 2.31, locus-specific LOD = 5.47). Each additional copy of an African ancestral allele at the 6p21.1 peak was associated with an average increase in CRVE of 6.14 mm in the hypertensives, but had no significant effects in the non-hypertensives (P for heterogeneity ,0.001). Further mapping in the 6p21.1 region may uncover novel genetic variants affecting retinal vascular caliber and further insights into the interaction between genetic effects of the microvascular system and hypertension