1,026 research outputs found
Black soliton in a quasi-one-dimensional trapped fermion-fermion mixture
Employing a time-dependent mean-field-hydrodynamic model we study the
generation of black solitons in a degenerate fermion-fermion mixture in a
cigar-shaped geometry using variational and numerical solutions. The black
soliton is found to be the first stationary vibrational excitation of the
system and is considered to be a nonlinear continuation of the vibrational
excitation of the harmonic oscillator state. We illustrate the stationary
nature of the black soliton, by studying different perturbations on it after
its formation.Comment: 7 pages, 10 figure
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Stakeholder identification of advanced technology opportunities at international ports of entry
As part of the Advanced Technologies for International and Intermodal Ports of Entry (ATIPE) Project, a diverse group of stakeholders was engaged to help identify problems experienced at inland international border crossings, particularly those at the US-Mexican border. The fundamental issue at international ports of entry is reducing transit time through the required documentation and inspection processes. Examples of other issues or problems, typically manifested as time delays at border crossings, repeatedly mentioned by stakeholders include: (1) lack of document standardization; (2) failure to standardize inspection processes; (3) inadequate information and communications systems; (4) manual fee and tariff collection; (5) inconsistency of processes and procedures; and (6) suboptimal cooperation among governmental agencies. Most of these issues can be addressed to some extent by the development of advanced technologies with the objective of allowing ports of entry to become more efficient while being more effective. Three categories of technologies were unambiguously of high priority to port of entry stakeholders: (1) automated documentation; (2) systems integration; and (3) vehicle and cargo tracking. Together, these technologies represent many of the technical components necessary for pre-clearance of freight approaching international ports of entry. Integration of vehicle and cargo tracking systems with port of entry information and communications systems, as well as existing industry legacy systems, should further enable border crossings to be accomplished consistently with optimal processing times
Making things happen : a model of proactive motivation
Being proactive is about making things happen, anticipating and preventing problems, and seizing opportunities. It involves self-initiated efforts to bring about change in the work environment and/or oneself to achieve a different future. The authors develop existing perspectives on this topic by identifying proactivity as a goal-driven process involving both the setting of a proactive goal (proactive goal generation) and striving to achieve that proactive goal (proactive goal striving). The authors identify a range of proactive goals that individuals can pursue in organizations. These vary on two dimensions: the future they aim to bring about (achieving a better personal fit within one’s work environment, improving the organization’s internal functioning, or enhancing the organization’s strategic fit with its environment) and whether the self or situation is being changed. The authors then identify “can do,” “reason to,” and “energized to” motivational states that prompt proactive goal generation and sustain goal striving. Can do motivation arises from perceptions of self-efficacy, control, and (low) cost. Reason to motivation relates to why someone is proactive, including reasons flowing from intrinsic, integrated, and identified motivation. Energized to motivation refers to activated positive affective states that prompt proactive goal processes. The authors suggest more distal antecedents, including individual differences (e.g., personality, values, knowledge and ability) as well as contextual variations in leadership, work design, and interpersonal climate, that influence the proactive motivational states and thereby boost or inhibit proactive goal processes. Finally, the authors summarize priorities for future researc
Continuous control of autoimmune disease by antigen-dependent polyclonal CD4+CD25+ regulatory T cells in the regional lymph node
This study investigated the unresolved issue of antigen-dependency and antigen-specificity of autoimmune disease suppression by CD4+CD25+ T cells (T regs). Based on autoimmune ovarian disease (AOD) in day 3 thymectomized (d3tx) mice and polyclonal T regs expressing the Thy1.1 marker, we determined: (a) the location of recipient T cell suppression, (b) the distribution of AOD-suppressing T regs, and (c) the relative efficacy of male versus female T regs. Expansion of recipient CD4+ T cells, activation/memory marker expression, and IFN-γ production were inhibited persistently in the ovary-draining LNs but not elsewhere. The cellular changes were reversed upon Thy1.1+ T reg depletion, with emergence of potent pathogenic T cells and severe AOD. Similar changes were detected in the regional LNs during autoimmune dacryoadenitis and autoimmune prostatitis suppression. Although the infused Thy1.1+ T regs proliferated and were disseminated in peripheral lymphoid organs, only those retrieved from ovary-draining LNs adoptively suppressed AOD at a suboptimal cell dose. By depriving d3tx recipients of ovarian antigens, we unmasked the supremacy of ovarian antigen-exposed female over male T regs in AOD suppression. Thus, disease suppression by polyclonal T regs depends on endogenous antigen stimulation; this occurs in a location where potent antigen-specific T regs accumulate and continuously negate pathogenic T cell response
Template-stripped gold surfaces with 0.4 nm rms roughness suitable for force measurements. Application to the Casimir force in the 20-100 nm range
Using a template-stripping method, macroscopic gold surfaces with
root-mean-square (rms) roughness less than 0.4 nm have been prepared, making
them useful for studies of surface interactions in the nanometer range. The
utility of such substrates is demonstrated by measurements of the Casimir force
at surface separations between 20 and 100 nm, resulting in good agreement with
theory. The significance and quantification of this agreement is addressed, as
well as some methodological aspects regarding the measurement of the Casimir
force with high accuracy.Comment: 7 figure
Managing your feelings at work, for a reason : the role of individual motives in affect regulation for performance-related outcomes at work
Affect regulation matters in organizations, but research has predominantly focused on how employees regulate their feelings. Here, we investigate the motives for why employees regulate their feelings. We assess employees’ engagement in affect regulation based on distinct motives and investigate their implications for performance-related outcomes. We develop a framework and measure for distinct types of motivated affect regulation at work, comprising hedonic affect regulation (motive to feel better), task-related affect regulation (motive to reach an achievement-related goal), and social affect regulation (motive to get along with others). Study 1 (N = 621 employees) indicated each type of motivated affect regulation was distinct from the others. In Study 2 (N = 80 employees; n = 821 observations), in line with our theorizing, hedonic and task-related affect regulation were both positively associated with performance-related outcomes via perceived affect-regulation success. In addition, the link between task-related affect regulation and perceived affect-regulation success was strongest for those individuals who habitually engage in deep acting. By contrast, social affect regulation did not predict perceived affect-regulation success or performance-related outcomes. Understanding why employees choose to manage their feelings advances insights on individual motives in employee behavior and provides new avenues for improving performance outcomes in organizations
Enhanced Joule Heating in Umbral Dots
We present a study of magnetic profiles of umbral dots (UDs) and its
consequences on the Joule heating mechanisms. Hamedivafa (2003) studied Joule
heating using vertical component of magnetic field. In this paper UDs magnetic
profile has been investigated including the new azimuthal component of magnetic
field which might explain the relatively larger enhancement of Joule heating
causing more brightness near circumference of UD.Comment: 8 pages, 1 figure, accepted in Solar Physic
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