1,509 research outputs found
Theory and applications of the Vlasov equation
Forty articles have been recently published in EPJD as contributions to the
topical issue "Theory and applications of the Vlasov equation". The aim of this
topical issue was to provide a forum for the presentation of a broad variety of
scientific results involving the Vlasov equation. In this editorial, after some
introductory notes, a brief account is given of the main points addressed in
these papers and of the perspectives they open.Comment: Editoria
Midline (dermoid) cysts of the floor of the mouth: report of 16 cases and review of surgical techniques.
Atomic Effective Pseudopotentials for Semiconductors
We derive an analytic connection between the screened self-consistent
effective potential from density functional theory (DFT) and atomic effective
pseudopotentials (AEPs). The motivation to derive AEPs is to address structures
with thousands to hundred thousand atoms, as given in most nanostructures. The
use of AEPs allows to bypass a self-consistent procedure and to address
eigenstates around a certain region of the spectrum (e.g., around the band
gap). The bulk AEP construction requires two simple DFT calculations of
slightly deformed elongated cells. The ensuing AEPs are given on a fine
reciprocal space grid, including the small reciprocal vector components, are
free of parameters, and involve no fitting procedure. We further show how to
connect the AEPs of different bulk materials, which is necessary to obtain
accurate band offsets. We derive a total of 20 AEPs for III-V, II-VI and group
IV semiconductors and demonstrate their accuracy and transferability by
comparison to DFT calculations of strained bulk structures, quantum wells with
varying thickness, and semiconductor alloys.Comment: 10 pages, 5 figures, submitted to PR
Clinical survey of neurosensory side-effects of mandibular parasymphyseal bone harvesting
The aim of the present survey was to assess neurosensory disturbances and/or tooth-pulp sensitivity losses after mandibular parasymphyseal bone-harvesting procedures. Twenty-eight harvesting areas in 16 patients were surveyed. Mucosal and skin sensitivity of the chin/lower lip, divided into four regions, were determined via Pointed-Blunt and Two-Point-Discrimination Tests. Pulp sensitivity of the mandibular teeth from the left second bicuspid to the right second bicuspid was tested by cold vitality preoperatively and 12 months postoperatively. Teeth were grouped according to sensitivity alterations and distance from the harvesting defects, as measured on CT scans, and statistically significant differences sought. At 12 months, 29% of preoperatively vital cuspids overlying the harvesting defects revealed pulp-sensitivity losses; no patient reported anaesthesia or analgesia; hypoaesthesia was present in 4% (8 sites; 2 patients), hypoalgesia was present in 3% (5 sites; 2 patients) and Two-Point-Discrimination Tests yielded pathologic responses in 5% of tested areas (10 sites; 4 patients). Teeth with and without pulp sensitivity changes were statistically indistinguishable regarding distances between root apices or mental foramen and the harvesting defect. The loss of pulp sensitivity in any tooth cannot be predicted simply on the basis of the distance between its apex and the harvesting osteotomy line
Tuning of the Gap in a Laughlin-Bychkov-Rashba Incompressible Liquid
We report on our investigation of the influence of Bychkov-Rashba spin-orbit
interaction (SOI) on the incompressible Laughlin state. We find that
experimentally obtainable values of the spin-orbit coupling strength can induce
as much as a 25% increase in the quasiparticle-quasihole gap Eg at low magnetic
fields in InAs, thereby increasing the stability of the liquid state. The
SOI-modulated enhancement of Eg is also significant for filling factors 1/5 and
1/7, where the FQH state is usually weak. This raises the intriguing
possibility of tuning, via the SO coupling strength, the liquid to solid
transition to much lower densities.Comment: 4 pages, 3 figure
Only the best for my kids: An extended TPB model to understand mothers’ use of food labels
Despite the evidence that mothers’ food purchasing behavior impacts the quality of children's diet, few studies have explored psycho-social factors influencing how mothers choose the food to buy for their children. To fill this gap, this study tested an extended Theory of Planned Behavior (TPB) model to predict mothers’ tendency to seek information on food labels before purchasing food for children. Participants included 311 Italian mothers who completed a self-report questionnaire measuring their information-seeking behavior, TPB variables, anticipated regret and healthy-eater identity. Results from a Multiple Correspondence Analysis showed that mothers’ information-seeking behavior involved a continuum of choices ranging from selecting conventional or prepackaged foods to choosing to read the food label before making a purchase. Besides, a Partial Least Squares–Structural Equation Modeling analysis showed that information-seeking behavior was positively predicted by intention (β = 0.309, p < 0.001) and healthy-eater identity (β = 0.195, p < 0.001). In turn, intention was positively affected by attitude (β = 0.208, p < 0.001), subjective norms (β = 0.155, p < 0.01), perceived behavioral control (β = 0.124, p < 0.05), anticipated regret (β = 0.193, p < 0.001), and healthy-eater identity (β = 0.191, p < 0.001). These findings emphasize that future initiatives could usefully target attitude, anticipated regret and self-identity to encourage mothers’ informed food choices for their children
Variety seeking behavior in the wine domain: A consumers segmentation using big data
This study investigates variety seeking behavior in the wine domain. Since variety seeking depends on brand strategies and consumers’ preferences for different types of vines and denominations, a bi-dimensional perspective is adopted. Two new variety seeking measures are defined, namely the Wine Index of Diversity and Brand Index of Diversity. A finite mixture regression model is implemented to identify and characterize groups of households sharing similar variety seeking behavior in a statistically representative sample of 8,313 Italian households. Four groups are identified based on consumer characteristics and their purchasing behavior. The largest group is “switchers,” which includes consumers showing a relatively higher wine diversity than brand diversity. Estimates reveal the “habitual” group, that lives in the southern Italy and consumes wine less frequently than all other groups. The “loyal” group includes the youngest consumers with an above average income, who reside in the northern regions. Finally, the “variety seekers” are older, have the highest incomes, and live in the central regions. This grouping provides insights into the effects of brand and wine typology on consumers’ choices
Generation of Subion Scale Magnetic Holes from Electron Shear Flow Instabilities in Plasma Turbulence
Magnetic holes (MHs) are coherent structures associated with strong magnetic field depressions in magnetized plasmas. They are observed in many astrophysical environments at a wide range of scales, but their origin is still under debate. In this work, we investigate the formation of subion scale MHs using a fully kinetic 2D simulation of plasma turbulence initialized with parameters typical of the Earth’s magnetosheath. Our analysis shows that the turbulence is capable of generating subion scale MHs from large scale fluctuations via the following mechanism: first, the nonlinear large scale dynamics spontaneously leads to the development of thin and elongated electron velocity shears; these structures then become unstable to the electron Kelvin-Helmholtz instability and break up into small scale electron vortices; the electric current carried by these vortices locally reduces the magnetic field, inducing the formation of subion scale MHs. The MHs thus produced exhibit features consistent with satellite observations and with previous numerical studies. We finally discuss the kinetic properties of the observed subion scale MHs, showing that they are characterized by complex non-Maxwellian electron velocity distributions exhibiting anisotropic and agyrotropic features
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