11 research outputs found
Quantum Rings in Electromagnetic Fields
This is the author accepted manuscript. The final version is available from Springer via the DOI in this recordThis chapter is devoted to optical properties of so-called Aharonov-Bohm
quantum rings (quantum rings pierced by a magnetic flux resulting in AharonovBohm
oscillations of their electronic spectra) in external electromagnetic fields.
It studies two problems. The first problem deals with a single-electron AharonovBohm
quantum ring pierced by a magnetic flux and subjected to an in-plane (lateral)
electric field. We predict magneto-oscillations of the ring electric dipole moment.
These oscillations are accompanied by periodic changes in the selection rules for
inter-level optical transitions in the ring allowing control of polarization properties
of the associated terahertz radiation. The second problem treats a single-mode microcavity
with an embedded Aharonov-Bohm quantum ring which is pierced by a
magnetic flux and subjected to a lateral electric field. We show that external electric
and magnetic fields provide additional means of control of the emission spectrum
of the system. In particular, when the magnetic flux through the quantum ring is
equal to a half-integer number of the magnetic flux quanta, a small change in the
lateral electric field allows for tuning of the energy levels of the quantum ring into
resonance with the microcavity mode, thus providing an efficient way to control
the quantum ring-microcavity coupling strength. Emission spectra of the system are
discussed for several combinations of the applied magnetic and electric fields
Theoretical and Experimental Investigations of Terahertz-Range Gyrotrons with Frequency and Spectrum Control
New approaches to investigating social gestures in autism spectrum disorder
<p>Abstract</p> <p>The combination of economic games and human neuroimaging presents the possibility of using economic probes to identify biomarkers for quantitative features of healthy and diseased cognition. These probes span a range of important cognitive functions, but one new use is in the domain of reciprocating social exchange with other humans - a capacity perturbed in a number of psychopathologies. We summarize the use of a reciprocating exchange game to elicit neural and behavioral signatures for subjects diagnosed with autism spectrum disorder (ASD). Furthermore, we outline early efforts to capture features of social exchange in computational models and use these to identify quantitative behavioral differences between subjects with ASD and matched controls. Lastly, we summarize a number of subsequent studies inspired by the modeling results, which suggest new neural and behavioral signatures that could be used to characterize subtle deficits in information processing during interactions with other humans.</p
A Distribution-Free Description of Fragmentation by Blasting Based on Dimensional Analysis
miR-23b and miR-218 silencing increase Muscleblind-like expression and alleviate myotonic dystrophy phenotypes in mammalian models
Preliminary evaluation of some aspects of the ecology (growth pattern, condition factor and reproductive biology) of African pike, Hepsetus odoe (Bloch 1794), in Lake Eleiyele, Ibadan, Nigeria
Abstract A preliminary investigation of length-weight relationship, condition factor and reproductive ecology of African pike fish, Hepsetus odoe, was conducted between June to August 2010 in Lake Eleiyele. A total of 90 samples of the fish species were caught by fishermen using gill nets. The results obtained showed that fish species had isometric growth pattern (contrary to negative allometry expected) with the growth exponent, b value of 2.64, that is not statistically different from 3 and with high statistical power of 0.866 when tested. The mean condition factor, K, was found to be 2.6, indicating that the fish species were in good condition in the study area. For reproductive biology, mean fecundity and gonadosomatic index were found to be 1349 eggs and 3.53% respectively. This study was necessary to fill the knowledge gap and provide information for management and conservation of the investigated species in the lake system. This study recommended that further research needs to be conducted because the sampling was carried out in the rainy season period and within a quarter of a year