Optical emission of strained direct-band-gap Ge quantum well embedded inside InGaAs alloy layers

We studied the optical properties of a strain-induced direct-band-gap Ge quantum well embedded in InGaAs. We showed that the band offsets depend on the electronegativity of the layer in contact with Ge, leading to different types of optical transitions in the heterostructure. When group-V atoms compose the interfaces, only electrons are confined in Ge, whereas both carriers are confined when the interface consists of group-III atoms. The different carrier confinement results in different emission dynamics behavior. This study provides a solution to obtain efficient light emission from Ge.

Extending the Theory of Planned Behavior in the Exercise Domain: A Study of Community College Students in an Urban Multicultural Setting

The purpose of this study was to assess the intention to exercise among ethnically and racially diverse community college students using the Theory of Planned Behavior (TPB). In addition to identifying the variables associated with motivation or intention of college students to engage in physical activity, this study tested the model of the Theory of Planned Behavior, asking: Does the TPB model explain intention to exercise among a racially/ethnically diverse group of college students? The relevant variables were the TPB constructs (behavioral beliefs, normative beliefs, and control beliefs), which combined to form a measure of intention to exercise. Structural Equation Modeling was used to test the predictive power of the TPB constructs for predicting intention to exercise. Following procedures described by Ajzen (2002), the researcher developed a questionnaire encompassing the external variables of student demographics (age, gender, work status, student status, socio-economic status, access to exercise facilities, and past behavior), major constructs of the TPB, and two questions from the Godin Leisure Time Questionnaire (GLTQ; Godin & Shephard, 1985). Participants were students (N = 255) who enrolled in an on-campus wellness course at an urban community college. The demographic profile of the sample revealed a racially/ethnically diverse study population. The original model that was used to reflect the TPB as developed by Ajzen was not supported by the data analyzed using SEM; however, a revised model that the researcher thought was theoretically a more accurate reflection of the causal relations between the TPB constructs was supported. The GLTQ questions were problematic for some students; those data could not be used in the modeling efforts. The GLTQ measure, however, revealed a significant correlation with intention to exercise (r = .27, p = .001). Post-hoc comparisons revealed significant differences in normative beliefs and attitude toward exercising behavior between Black students and Hispanic students. Compared to Black students, Hispanic students were more likely to (a) perceive “friends” as approving of them being physically active and (b) rate being physically active for 30 minutes per day as “beneficial”. No statistically significant difference was found among groups on overall intention to exercise.

A Frequency-Dependent Equivalence Between Groove Gap Waveguide and Rectangular Waveguide

Recently gap waveguides have been shown as a potential alternative to conventional waveguides in the millimeter-wave band. Groove Gap Waveguide (GGW) has until now been studied though direct correspondence with rectangular waveguide with the same propagation channel dimensions. However there have been observed differences in the above cutoff propagation characteristics between these waveguide types. Furthermore, the behaviour of GGW below cutoff remains unknown. This work presents a discussion of below and above cutoff propagation characteristics, and introduces a simple model that explains observed GGW behavior and establishes its propagation characteristics.

Behavior change theory, content and delivery of interventions to enhance adherence in chronic respiratory disease: A systematic review

Background: We sought to describe the theory used to design treatment adherence interventions, the content delivered, and the mode of delivery of these interventions in chronic respiratory disease. Methods: We included randomized controlled trials of adherence interventions (compared to another intervention or control) in adults with chronic respiratory disease (8 databases searched; inception until March 2015). Two reviewers screened and extracted data: post-intervention adherence (measured objectively); behavior change theory, content (grouped into psychological, education and self-management/supportive, telemonitoring, shared decision-making); and delivery. “Effective” studies were those with p < 0.05 for adherence rate between groups. We conducted a narrative synthesis and assessed risk of bias. Results: 12,488 articles screened; 46 included studies (n = 42,91% in OSA or asthma) testing 58 interventions (n = 27, 47% were effective). Nineteen (33%) interventions (15 studies) used 12 different behavior change theories. Use of theory (n = 11,41%) was more common amongst effective interventions. Interventions were mainly educational, self-management or supportive interventions (n = 27,47%). They were commonly delivered by a doctor (n = 20,23%), in face-to-face (n = 48,70%), one-to-one (n = 45,78%) outpatient settings (n = 46,79%) across 2–5 sessions (n = 26,45%) for 1–3 months (n = 26,45%). Doctors delivered a lower proportion (n = 7,18% vs n = 13,28%) and pharmacists (n = 6,15% vs n = 1,2%) a higher proportion of effective than ineffective interventions. Risk of bias was high in >1 domain (n = 43, 93%) in most studies. Conclusions: Behavior change theory was more commonly used to design effective interventions. Few adherence interventions have been developed using theory, representing a gap between intervention design recommendations and research practice.

Adhésion au traitement antidiabétique oral chez les adultes atteints de diabète de type 2 : déterminants et interventions visant à l'améliorer

Introduction : Le diabète de type 2 est une maladie évolutive débilitante et souvent mortelle qui atteint de plus en plus de personnes dans le monde. Le traitement antidiabétique non-insulinique (TADNI) notamment le traitement antidiabétique oral (TADO) est le plus fréquemment utilisé chez les adultes atteints de cette maladie. Toutefois, plusieurs de ces personnes ne prennent pas leur TADO tel que prescrit posant ainsi la problématique d’une adhésion sous-optimale. Ceci entraîne des conséquences néfastes aussi bien pour les patients que pour la société dans laquelle ils vivent. Il serait donc pertinent d’identifier des pistes de solution à cette problématique. Objectifs : Trois objectifs de recherche ont été étudiés : 1) Explorer la capacité de la théorie du comportement planifié (TCP) à prédire l’adhésion future au TADNI chez les adultes atteints de diabète de type 2, 2) Évaluer l’efficacité globale des interventions visant à améliorer l’adhésion au TADO chez les adultes atteints de diabète de type 2 et étudier l’influence des techniques de changement de comportement sur cette efficacité globale, et 3) Évaluer l’efficacité globale de l’entretien motivationnel sur l’adhésion au traitement médicamenteux chez les adultes atteints de maladie chronique et étudier l’influence des caractéristiques de cette intervention sur son efficacité globale. Méthodes : Pour l’objectif 1 : Il s’agissait d’une enquête web, suivie d’une évaluation de l’adhésion au TADNI sur une période de 30 jours, chez des adultes atteints de diabète de type 2, membres de Diabète Québec. L’enquête consistait à la complétion d’un questionnaire auto-administré incluant les variables de la TCP (intention, contrôle comportemental perçu et attitude) ainsi que d’autres variables dites «externes». Les informations relatives au calcul de l’adhésion provenaient des dossiers de pharmacie des participants transmis via la plateforme ReMed. Une régression linéaire multivariée a été utilisée pour estimer la mesure d’association entre l’intention et l’adhésion future au TADNI ainsi que l’interaction entre l’adhésion passée et l’intention. Pour répondre aux objectifs 2 et 3, deux revues systématiques et méta-analyses ont été effectuées et rapportées selon les lignes directrices de PRISMA. Un modèle à effets aléatoires a été utilisé pour estimer l’efficacité globale (g d’Hedges) des interventions et son intervalle de confiance à 95 % (IC95%) dans chacune des revues. Nous avons également quantifié l’hétérogénéité (I2 d’Higgins) entre les études, et avons fait des analyses de sous-groupe et des analyses de sensibilité. Résultats : Objectif 1 : Il y avait une interaction statistiquement significative entre l’adhésion passée et l’intention (valeur-p= 0,03). L’intention n’était pas statistiquement associée à l’adhésion future au TADNI, mais son effet était plus fort chez les non-adhérents que chez les adhérents avant l’enquête web. En revanche, l’intention était principalement prédite par le contrôle comportemental perçu à la fois chez les adhérents [β= 0,90, IC95%= (0,80; 1,00)] et chez les non-adhérents passés [β= 0,76, IC95%= (0,56; 0,97)]. Objectif 2 : L’efficacité globale des interventions sur l’adhésion au TADO était de 0,21 [IC95%= (-0,05; 0,47); I2= 82 %]. L’efficacité globale des interventions dans lesquelles les intervenants aidaient les patients et/ou les cliniciens à être proactifs dans la gestion des effets indésirables était de 0,64 [IC95%= (0,31; 0,96); I2= 56 %]. Objectif 3 : L’efficacité globale des interventions (basées sur l’entretien motivationnel) sur l’adhésion au traitement médicamenteux était de 0,12 [IC95%= (0,05; 0,20); I2= 1 %. Les interventions basées uniquement sur l’entretien motivationnel [β= 0,18, IC95%= (0,00; 0,36)] et celles dans lesquelles les intervenants ont été coachés [β= 0,47, IC95%= (0,03; 0,90)] étaient les plus efficaces. Aussi, les interventions administrées en face-à-face étaient plus efficaces que celles administrées par téléphone [β= 0,27, IC95%=(0,04; 0,50)]. Conclusion : Il existe un écart entre l’intention et l’adhésion future au TADNI, qui est partiellement expliqué par le niveau d’adhésion passée. Toutefois, il n’y avait pas assez de puissance statistique pour démontrer une association statistiquement significative entre l’intention et l’adhésion future chez les non-adhérents passés. D’un autre côté, quelques solutions au problème de l’adhésion sous-optimale au TADO ont été identifiées. En effet, le fait d’aider les patients et/ou les cliniciens à être proactifs dans la gestion des effets indésirables contribue efficacement à l’amélioration de l’adhésion au TADO chez les adultes atteints de diabète de type 2. Aussi, les interventions basées sur l’entretien motivationnel améliorent efficacement l’adhésion au traitement médicamenteux chez les adultes atteints de maladie chronique. L’entretien motivationnel pourrait donc être utilisé comme un outil clinique pour soutenir les patients dans l’autogestion de leur TADO.

Black-White Wage Gap Among Restaurant Servers: A Replication, Extension, and Exploration of Consumer Racial Discrimination in Tipping

There is a rich history of social science research centering on racial inequalities that continue to be observed across various markets (e.g., labor, housing, and credit markets) and social milieus. Existing research on racial discrimination in consumer markets, however, is relatively scarce and that which has been done has disproportionately focused on consumers as the victims of race-based mistreatment. As such, we know relatively little about how consumers contribute to inequalities in their roles as perpetrators of racial discrimination. In response, in this paper we elaborate on a line of research that is only in its’ infancy stages of development and yet is ripe with opportunities to advance the literature on consumer racial discrimination and racial earnings inequities among tip dependent employees in the United States. Specifically, we analyze data derived from a large exit survey of restaurant consumers (n=378) in an attempt to replicate, extend, and further explore the recently documented effect of service providers’ race on restaurant consumers’ tipping decisions. Our results indicate that both White and Black restaurant customers discriminate against Black servers by tipping them less than their White coworkers. Importantly, we find no evidence that this Black tip penalty is the result of interracial differences in service skills possessed by Black and White servers. We conclude by delineating directions for future research in this neglected but salient area study.

An examination of factors that influence entrepreneurial intention of high school students in Kenya

Abstract Considerable research has been carried out on entrepreneurship in efforts to understand its incidence in order to influence and maximize its benefits. Essentially, researchers and policy makers have sought to understand the link between individuals and business creation: Why some people start businesses while others do not. The research indicates that personality traits, individual background factors and association of entrepreneurship with career choice and small business enterprises, cannot sufficiently explain entrepreneurship. It is recognized that entrepreneurship is an intentional process and based on Ajzen’s Theory of Planned Behavior, the most defining characteristic of entrepreneurship is the intention to start a business. The purpose of this study was, therefore, to examine factors that influence entrepreneurial intention in high school students in Kenya. Specifically, the study aimed at determining if there were relationships between the perceptions of desirability, and feasibility of entrepreneurship with entrepreneurial intention of the students, identifying any difference in these perceptions with students of different backgrounds, and developing a model to predict entrepreneurship in the students. The study, therefore, tested how well Ajzen’s Theory of Planned Behavior applied in the Kenyan situation. A questionnaire was developed and administered to 969 final year high school students at a critical important point in their career decision making. Participants were selected using a combined convenience and random sampling technique, considering gender, rural/urban location, cost, and accessibility. Survey was the major method of data collection. Data analysis methods included descriptive statistics, correlation, ANOVA, factor analysis, effect size, and regression analysis. iii The findings of this study corroborate results from past studies. Attitudes are found to influence intention, and the attitudes to be moderated by individual background factors. Perceived personal desirability of entrepreneurship was found to have the greatest influence on entrepreneurial intention and perceived feasibility the lowest. The study findings also showed that perceived social desirability and feasibility of entrepreneurship contributed to perception of personal desirability, and that the background factors, including gender and prior experience, influenced entrepreneurial intention both directly and indirectly. In addition, based on the literature reviewed, the study finds that entrepreneurship promotion requires reduction of the high small business mortality rate and creation of both entrepreneurs and entrepreneurial opportunities (Kruger, 2000; Shane & Venkataraman, 2000). These findings have theoretical and practical implications for researchers, policy makers, teachers, and other entrepreneurship practitioners in Kenya.

Gap junctions and emergent rhythms

Gap junction coupling is ubiquitous in the brain, particularly between the dendritic trees of inhibitory interneurons. Such direct non-synaptic interaction allows for direct electrical communication between cells. Unlike spike-time driven synaptic neural network models, which are event based, any model with gap junctions must necessarily involve a single neuron model that can represent the shape of an action potential. Indeed, not only do neurons communicating via gaps feel super-threshold spikes, but they also experience, and respond to, sub-threshold voltage signals. In this chapter we show that the so-called absolute integrate-and-fire model is ideally suited to such studies. At the single neuron level voltage traces for the model may be obtained in closed form, and are shown to mimic those of fast-spiking inhibitory neurons. Interestingly in the presence of a slow spike adaptation current the model is shown to support periodic bursting oscillations. For both tonic and bursting modes the phase response curve can be calculated in closed form. At the network level we focus on global gap junction coupling and show how to analyze the asynchronous firing state in large networks. Importantly, we are able to determine the emergence of non-trivial network rhythms due to strong coupling instabilities. To illustrate the use of our theoretical techniques (particularly the phase-density formalism used to determine stability) we focus on a spike adaptation induced transition from asynchronous tonic activity to synchronous bursting in a gap-junction coupled network.

THE INFLUENCE OF URBAN FORM AT DIFFERENT GEOGRAPHICAL SCALES ON TRAVEL BEHAVIOR; EVIDENCE FROM U.S. CITIES

Suburban lifestyle is popular among American families, although it has been criticized for encouraging automobile use through longer commutes, causing heavy traffic congestion, and destroying open spaces (Handy, 2005). It is a serious concern that people living in low-density suburban areas suffer from high automobile dependency and lower rates of daily physical activity, both of which result in social, environmental and health-related costs. In response to such concerns, researchers have investigated the inter-relationships between urban land-use pattern and travel behavior within the last few decades and suggested that land-use planning can play a significant role in changing travel behavior in the long-term. However, debates regarding the magnitude and efficiency of the effects of land-use on travel patterns have been contentious over the years. Changes in built-environment patterns is potentially considered a long-term panacea for automobile dependency and traffic congestion, despite some researchers arguing that the effects of land-use on travel behavior are minor, if any. It is still not clear why the estimated impact is different in urban areas and how effective a proposed land-use change/policy is in changing certain travel behavior. This knowledge gap has made it difficult for decision-makers to evaluate land-use plans and policies. In addition, little is known about the influence of the large-scale built environment. In the present dissertation, advanced spatial-statistical tools have been employed to better understand and analyze these impacts at different scales, along with analyzing transit-oriented development policy at both small and large scales. The objective of this research is to: (1) develop scalable and consistent measures of the overall physical form of metropolitan areas; (2) re-examine the effects of built-environment factors at different hierarchical scales on travel behavior, and, in particular, on vehicle miles traveled (VMT) and car ownership; and (3) investigate the effects of transit-oriented development on travel behavior. The findings show that changes in built-environment at both local and regional levels could be very influential in changing travel behavior. Specifically, the promotion of compact, mixed-use built environment with well-connected street networks reduces VMT and car ownership, resulting in less traffic congestion, air pollution, and energy consumption.

The effect of ambient scent on moviegoers’ behavior

Atmospheres influence behavior, create a positive image, and influence consumer purchasing patterns and retail perceptions. Nonetheless, the physical environment is a potential source of competitive advantage, though neglected more often than not. In particular, research on the effects of aroma as an independent variable in natural settings is very limited and requires further research. A sample of 407 moviegoers participated in a “natural experiment” in a cinema complex, using scented and unscented conditions. Findings show that scent produces significant positive differences in the evaluation of the theater, its environment, and on intention to return. No significant differences are found in the evaluations of concession products sold, despite the fact that spectators in scented rooms considered product prices to be significantly cheaper than did spectators in unscented rooms. A major implication of this study is that scent significantly affects emotional reactions to atmospheres. Retailers can thus improve environments to create enjoyable experiences and positively influence consumer responses.

The Behavior of Hydroxyl Units of Synthetic Goethite and its Dehydroxylated Product Hematite

The behavior of the hydroxyl units of synthetic goethite and its dehydroxylated product hematite was characterized using a combination of Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) during the thermal transformation over a temperature range of 180-270 degrees C. Hematite was detected at temperatures above 200 degrees C by XRD while goethite was not observed above 230 degrees C. Five intense OH vibrations at 3212-3194, 1687-1674, 1643-1640, 888-884 and 800-798 cm(-1), and a H2O vibration at 3450-3445 cm(-1) were observed for goethite. The intensity of hydroxyl stretching and bending vibrations decreased with the extent of dehydroxylation of goethite. Infrared absorption bands clearly show the phase transformation between goethite and hematite: in particular. the migration of excess hydroxyl units from goethite to hematite. Two bands at 536-533 and 454-452 cm(-1) are the low wavenumber vibrations of Fe-O in the hematite structure. Band component analysis data of FTIR spectra support the fact that the hydroxyl units mainly affect the a plane in goethite and the equivalent c plane in hematite.

Automated Feedback for 'Fill in the Gap' Programming Exercises

Timely feedback is a vital component in the learning process. It is especially important for beginner students in Information Technology since many have not yet formed an effective internal model of a computer that they can use to construct viable knowledge. Research has shown that learning efficiency is increased if immediate feedback is provided for students. Automatic analysis of student programs has the potential to provide immediate feedback for students and to assist teaching staff in the marking process. This paper describes a “fill in the gap” programming analysis framework which tests students’ solutions and gives feedback on their correctness, detects logic errors and provides hints on how to fix these errors. Currently, the framework is being used with the Environment for Learning to Programming (ELP) system at Queensland University of Technology (QUT); however, the framework can be integrated into any existing online learning environment or programming Integrated Development Environment (IDE)