Coupling Poisson and Jacobi structures on foliated manifolds

Let M be a differentiable manifold endowed with a foliation F. A Poisson structure P on M is F-coupling if the image of the annihilator of TF by the sharp-morphism defined by P is a normal bundle of the foliation F. This notion extends Sternberg's coupling symplectic form of a particle in a Yang-Mills field. In the present paper we extend Vorobiev's theory of coupling Poisson structures from fiber bundles to foliations and give simpler proofs of Vorobiev's existence and equivalence theorems of coupling Poisson structures on duals of kernels of transitive Lie algebroids over symplectic manifolds. Then we discuss the extension of the coupling condition to Jacobi structures on foliated manifolds.Comment: LateX, 38 page

Interprofessional learning in practice: The student experience

Interprofessional learning and the development of teamworking skills are recognised as essential for patient care and are also a government priority for undergraduate education. Sixteen occupational therapy students worked on an interprofessional training ward as part of their practice placement and three of them participated in an evaluation using the nominal group technique. Despite this small number, the evaluation identifies the value of this learning experience in giving the students an opportunity to appreciate the importance of interpersonal skills; to learn about other team members’ roles; and to experience the challenges of working on a busy rehabilitation ward for older people

An exploratory investigation of food choice behavior of teenagers with and without food allergies

Background - Understanding food choice behavior in adolescence is important because many core eating habits may be tracked into adulthood. The food choices of at least 2.3% of teenagers living in the United Kingdom are determined by food allergies. However, the effect of food allergies on eating habits in teenagers has not yet been studied.Objective - To provide an understanding of how teenagers with food allergies make food choice decisions and how these differ from those of non–food-allergic teenagers.Methods - One focus group discussion with non–food-allergic teenagers (n = 11) and 14 semistructured interviewers (7 with food-allergic and 7 with non–food-allergic teenagers) were performed (age range, 12-18 years). The focus group discussion and interviews were audiorecorded, transcribed verbatim, and analyzed using thematic content analysis.Results - Teenagers from both groups (food-allergic and non–food-allergic) named sensory characteristics of foods as the main reason for choosing them. Some food-allergic teenagers downplayed their allergy and frequently engaged in risk-taking behavior in terms of their food choices. However, they reported difficulties in trying new foods, especially when away from home. Parental control was experienced as protective by those with food allergies, whereas non–food-allergic teenagers felt the opposite. Most teenagers, including food-allergic ones, expressed the wish to eat similar foods to their friends. Other themes did not vary between the 2 groups.Conclusion - Food-allergic teenagers strive to be able to make similar food choices to their friends, although differences to non–food-allergic teenagers exist. It is important to address these differences to improve their dietary management

Analytical description of mixed ohmic and space-charge-limited conduction in single-carrier devices

While space-charge-limited current measurements are often used to characterize charge-transport in relatively intrinsic, low-mobility semiconductors, it is currently difficult to characterize lightly or heavily doped semiconductors with this method. By combining the theories describing ohmic and space-charge-limited conduction, we derive a general analytical approach to extract the charge-carrier density, the conduction-band edge and the drift components of the current density-voltage curves of a single-carrier device when the semiconductor is either undoped, lightly doped or heavily doped. The presented model covers the entire voltage range, i.e., both the low-voltage regime and the Mott-Gurney regime. We demonstrate that there is an upper limit to how doped a device must be before the current density-voltage curves are significantly affected, and we show that the background charge-carrier density must be considered to accurately model the drift component in the low-voltage regime, regardless of whether the device is doped or not. We expect that the final analytical expressions presented herein to be directly useful to experimentalists studying charge transport in novel materials and devices

Relationship between maternal and child behaviors in pediatric food allergy: an exploratory study

Parents play an important role in developing young children's food choices. They influence children's eating environments through the foods they make available, their own eating behavior, and the quality of their interactions with children in eating contexts

An Evaluation of Radar Metaphors for Providing Directional Stimuli Using Non-Verbal Sound

We compared four audio-based radar metaphors for providing directional stimuli to users of AR headsets. The metaphors are clock face, compass, white noise, and scale. Each metaphor, or method, signals the movement of a virtual arm in a radar sweep. In a user study, statistically significant differences were observed for accuracy and response time. Beat-based methods (clock face, compass) elicited responses biased to the left of the stimulus location, and non-beat-based methods (white noise, scale) produced responses biased to the right of the stimulus location. The beat methods were more accurate than the non-beat methods. However, the non-beat methods elicited quicker responses. We also discuss how response accuracy varies along the radar sweep between methods. These observations contribute design insights for non-verbal, nonvisual directional prompting

The physical meaning of time-delayed collection field transients from disordered devices

Charge carrier mobility and recombination determine the performance of many opto-electronic devices such as solar cells, sensors, and light-emitting diodes. Understanding how these parameters change as a function of material choice, charge carrier density, and device geometry is essential for developing the next generation of devices. The time-delayed collection field (TDCF) technique is becoming a widely used method to measure both recombination and carrier transport with values derived from this method being widely reported for many material systems. However, most novel materials are highly disordered with a high density of trap states and standard TDCF theory neglects the influence of these states. In this work, we examine how reliable TDCF can be as a measurement technique when the device contains significant energetic disorder. We identify regimes where the results can be relied upon and where the results should be taken with more caution. Finally, we provide simple and easy to use experimental tests to help the experimentalist decide whether the physical processes are dominated by trap states

Cohomology of skew-holomorphic Lie algebroids

We introduce the notion of skew-holomorphic Lie algebroid on a complex manifold, and explore some cohomologies theories that one can associate to it. Examples are given in terms of holomorphic Poisson structures of various sorts.Comment: 16 pages. v2: Final version to be published in Theor. Math. Phys. (incorporates only very minor changes

Arguing and negotiating in the presence of social influences

Postprin

Understanding the limits of plasmonic enhancement in organic photovoltaics

Plasmonic enhancement in organic photovoltaics has been extensively studied in the past decade. However, the reported improvements in power conversion efficiency (PCE) are highly inconsistent due to a poor understanding of the limitations of how plasmonics affect charge generation and transport in solar cells. In this work, we address these long-standing uncharted questions as to when plasmonic enhancements are useful and when they are not. We do this with a model system consisting of poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b:3,4-b′]dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)]:[6,6]-phenyl C61 butyric acid methyl ester PCDTBT polymer active layer with silver nanostructures embedded in the poly(3,4-ethylenedioxythiophene):polystyrene PEDOT:PSS sulfonate hole-transport layer. We demonstrate that: (a) plasmonic enhancements are most pronounced when the charge carrier mobilities of the donor and acceptor materials are unbalanced; (b) the introduction of plasmonic nanostructures in devices with balanced charge transport usually results in a decrease in efficiency; (c) plasmonic enhancement is highly shape-dependent; (d) for devices with asymmetric mobilities, as long as the species with low mobility is extracted at the contact where light is incident, device efficiency will be boosted; and (e) increase in light absorption in the active layer has minimal impact on PCE; the efficiency is primarily driven by exciton generation and charge collection efficiency. The findings of our work provide a generalized framework to guide researchers as to when plasmonic effects could be helpful to a device and when they could degrade performance