Rapid rotation of a Bose-Einstein condensate in a harmonic plus quartic trap

A two-dimensional rapidly rotating Bose-Einstein condensate in an anharmonic trap with quadratic and quartic radial confinement is studied analytically with the Thomas-Fermi approximation and numerically with the full time-independent Gross-Pitaevskii equation. The quartic trap potential allows the rotation speed $\Omega$ to exceed the radial harmonic frequency $\omega_\perp$. In the regime $\Omega \gtrsim \omega_\perp$, the condensate contains a dense vortex array (approximated as solid-body rotation for the analytical studies). At a critical angular velocity $\Omega_h$, a central hole appears in the condensate. Numerical studies confirm the predicted value of $\Omega_h$, even for interaction parameters that are not in the Thomas-Fermi limit. The behavior is also investigated at larger angular velocities, where the system is expected to undergo a transition to a giant vortex (with pure irrotational flow).Comment: 14 pages, 5 figure

Quantum simulation of multiple-exciton generation in a nanocrystal by a single photon

We have shown theoretically that efficient multiple exciton generation (MEG) by a single photon can be observed in small nanocrystals (NCs). Our quantum simulations that include hundreds of thousands of exciton and multi-exciton states demonstrate that the complex time-dependent dynamics of these states in a closed electronic system yields a saturated MEG effect on a picosecond timescale. Including phonon relaxation confirms that efficient MEG requires the exciton--biexciton coupling time to be faster than exciton relaxation time

Measuring Multiple Demographic Rates in Two Populations of Northern Bobwhite

Demographic rates of northern bobwhite (Colinus virginianus; hereafter, bobwhite) may vary spatially and temporally, and understanding the significance of these individual rates to population performance is critically important to bobwhite management. We present descriptive evidence from 2 populations that were simultaneously monitored from 2015–2020 that suggests different demographic rates can be more important to population performance than other demographic rates within the same region. Our objective was to understand the relative importance of various demographic rates to population performance in separate and seemingly stable populations. We monitored bobwhite seasonal survival and reproductive demographics on 2,475 bobwhites via radio-telemetry and estimated fall density using fall covey counts. Both sites maintained high densities (i.e., ≥3.45 birds/hectare) and remained relatively stable throughout the study period. On one site in the Red Hills region near Monticello, Florida, USA, bobwhite experienced comparatively low seasonal survival, but higher reproduction, including more frequent multiple-brood production. One hundred and twenty-nine kilometers away on a study site near Albany, Georgia, USA, bobwhite demonstrated consistently higher survival and lower reproductive output, including less multiple-brooding compared to the Red Hills population. This suggests, at a minimum, that compensatory or density-dependent reproduction may be occurring in these populations and regional population dynamics can vary locally even among stable populations

Exploring the Feasibility of Assessing Cultural Competence in Police Officers

Pathology, personality, and integrity-related construct assessments have been widely used in the selection of police officers. However, the incidence of police brutality and misconduct is still concerning. The present study explored the feasibility of the assessment of cultural competence in police officers. We explored the extent to which the change to the agency’s first ever Black CEO would affect cultural competence of the officers as well as incidence of misconduct. Results showed that scores on a cultural competence factor of an in-basket simulation used for promotional assessments at a state highway patrol agency were not predictive of either supervisor-rated performance or incidence of misconduct. Whereas results showed that misconduct was not predicted by the agency’s first Black CEO, cultural competence of the officers did increase after the change in command. Practical implications for law enforcement agencies and suggestions for future research are discussed

Retesting in a promotional process: Amount of time between tests accounting for magnitude of score increases

There are many reasons why an applicant may retake a selection test, whether it’s due to reasons outside of their control or perhaps their first test administration was unsuccessful. Research has shown that scores generally increase when applicants retake a test. However, research on situational judgment tests and in-basket simulations have been overshadowed by research on admissions tests, cognitive ability tests, and personality tests. Further, much research has focused on retesting effects during the initial selection process, but the current research aims to shed light on retesting effects during the promotional process. The literature shows conflicting findings regarding time between tests. While some literature says that more time between tests results in larger score increases, other research says that less time between tests results in larger score increases. The current study aims to clarify this conflicting history of research while closing the gap on types of assessments examined in the retesting literature. Results showed that more time between tests resulted in larger score gains for both the SJT and in the in-basket simulation. This is probably due to the nature of the test. SJTs and In-Baskets require a lot of job knowledge. Having more time on the job between tests would allow candidates to learn more and apply that on their second attempt at promotion. The literature on time between supports this notion. Studies that showed less time between tests resulted in larger score increases were assessing some aspect of cognitive ability. Perhaps for other tests less time between tests allows for greater score increases, but for job knowledge tests, more time between tests allows for these greater score increases. Practical implications and areas for future research are discussed. Keywords: retesting, promotion, in-basket, situational judgment tes

Individual Differences in Amygdala and Ventromedial Prefrontal Cortex Activity are Associated with Evaluation Speed and Psychological Well-being

Using functional magnetic resonance imaging, we examined whether individual differences in amygdala activation in response to negative relative to neutral information are related to differences in the speed with which such information is evaluated, the extent to which such differences are associated with medial prefrontal cortex function, and their relationship with measures of trait anxiety and psychological well-being (PWB). Results indicated that faster judgments of negative relative to neutral information were associated with increased left and right amygdala activation. In the prefrontal cortex, faster judgment time was associated with relative decreased activation in a cluster in the ventral anterior cingulate cortex (ACC, BA 24). Furthermore, people who were slower to evaluate negative versus neutral information reported higher PWB. Importantly, higher PWB was strongly associated with increased activation in the ventral ACC for negative relative to neutral information. Individual differences in trait anxiety did not predict variation in judgment time or in amygdala or ventral ACC activity. These findings suggest that people high in PWB effectively recruit the ventral ACC when confronted with potentially aversive stimuli, manifest reduced activity in subcortical regions such as the amygdala, and appraise such information as less salient as reflected in slower evaluative speed

Quantum kinetic approach to the calculation of the Nernst effect

We show that the strong Nernst effect observed recently in amorphous superconducting films far above the critical temperature is caused by the fluctuations of the superconducting order parameter. We employ the quantum kinetic approach for the derivation of the Nernst coefficient. We present here the main steps of the calculation and discuss some subtle issues that we encountered while calculating the Nernst coefficient. In particular, we demonstrate that in the limit T=0 the contribution of the magnetization ensures the vanishing of the Nernst signal in accordance with the third law of thermodynamics. We obtained a striking agreement between our theoretical calculations and the experimental data in a broad region of temperatures and magnetic fields.Comment: 24 pages, 13 figure

Amygdala and ventromedial prefrontal cortex are inversely coupled during regulation of negative affect and predict the diurnal pattern of cortisol secretion among older adults

Among younger adults, the ability to willfully regulate negative affect, enabling effective responses to stressful experiences, engages regions of prefrontal cortex (PFC) and the amygdala. Because regions of PFC and the amygdala are known to influence the hypothalamic-pituitary-adrenal axis, here we test whether PFC and amygdala responses during emotion regulation predict the diurnal pattern of salivary cortisol secretion. We also test whether PFC and amygdala regions are engaged during emotion regulation in older (62- to 64-year-old) rather than younger individuals. We measured brain activity using functional magnetic resonance imaging as participants regulated (increased or decreased) their affective responses or attended to negative picture stimuli. We also collected saliva samples for 1 week at home for cortisol assay. Consistent with previous work in younger samples, increasing negative affect resulted in ventral lateral, dorsolateral, and dorsomedial regions of PFC and amygdala activation. In contrast to previous work, decreasing negative affect did not produce the predicted robust pattern of higher PFC and lower amygdala activation. Individuals demonstrating the predicted effect (decrease s attend in the amygdala), however, exhibited higher signal in ventromedial prefrontal cortex (VMPFC) for the same contrast. Furthermore, participants displaying higher VMPFC and lower amygdala signal when decreasing compared with the attention control condition evidenced steeper, more normative declines in cortisol over the course of the day. Individual differences yielded the predicted link between brain function while reducing negative affect in the laboratory and diurnal regulation of endocrine activity in the home environment

The effects of self-efficacy, perceptions of ethical misconduct, and guilt-proneness on CWBs

This study examined the relationship between generalized self-efficacy, perceptions of ethical misconduct, guilt-proneness, and counterproductive work behaviors. We first hypothesized that self-efficacy would be negatively related to counterproductive work behaviors. Secondly, we hypothesized that perceptions of ethical misconduct and levels of guilt-proneness would mediate the negative relationship between generalized self-efficacy and counterproductive work behaviors. We surveyed 190 undergraduate students. To test our hypotheses, we used serial mediation (self-efficacy perceptions of ethical misconduct Guilt CWBs). Results supported our first hypothesis. However, we did not find support for the mediated relationship proposed in our second hypothesis

Examining Factors Influencing Use of a Decision Aid in Personnel Selection

In this research, two studies were conducted to examine factors influencing reliance on a decision aid in personnel selection. Specifically, this study examined the effect of feedback, validity of selection predictors, and presence of a decision aid on the use of the aid in personnel selection. The results demonstrate that when people are provided with the decision aid, their predictions were significantly more similar to the predictions made by the aid than people who were not provided with the aid. This suggests that when people are provided with an aid, they will use it to some degree. This research also shows that when provided with a decision aid with high cue validity, people will increase their reliance on the decision aid over multiple decisions