Public Service Motivation, Role Ambiguity, and Job Satisfaction Among Municipal Police Officers

Research in public management consistently asserts that public service motivation (PSM) facilitates beneficial work behaviors and attitudes. However, few studies have been designed to examine PSM in specific occupations. Law enforcement agencies may provide unique places to examine PSM because the public benefit of policing is directly and immediately observable by officers. Yet, law enforcement occupations are highly stressful. This study attempts to connect one form of occupational stress - role ambiguity -, public service motivation, and job satisfaction in municipal police officers. Findings from a regression model indicate that the dimensions of public service motivation are important drivers of job satisfaction among police officers. Findings also suggest that minimizing occupational stress, in the form of clarifying organizational roles, plays a significant, and primary, role in shaping job satisfaction

Analyzing oral skills in voice e-mail and online interviews

This study investigated the acquisition of speaking skills in an online distance education course of 19 first semester Spanish learners. The possibility of oral development in a strictly online course was examined based on students' pronunciation production in two types of recorded speaking activities and in two real-time conversations. Students created two types of voiced audio e-mails each week during the semester: read aloud passages and grammar-drill completions. In order to determine whether students' pronunciation indeed improved over the course of the semester, their performance on these two types of audio e-mails were compared at the beginning of the semester and at the end of the semester. In addition, students participated in two Internet-mediated oral conversations with their instructor using MSN messaging at the mid-term week and final week of the semester. Three kinds of data were collected from the conversations: an articulation score (articulation = pronunciation, stress, and intonation), an accuracy score, and a proficiency score. Students' performance on these interviews provided further evidence regarding the development of their oral skills. The findings suggest that only in the area of oral proficiency were there significant gains in scores

Epiconvergence of a Sequence of Level Sums of Convex Functions

We consider the problem of minimizing the max of two convex functions from both approximation and sensitivity point of view.This lead up to study the epiconvergence of a sequence of level sums of convex functions and the related dual problems

Around a Farkas type Lemma

The first two authors of this paper asserted in Lemma 4 of "New Farkas-type constraint qualifications in convex infinite programming" (DOI: 10.1051/cocv:2007027) that a given reverse convex inequality is consequence of a given convex system satisfying the Farkas-Minkowski constraint qualification if and only if certain set depending on the data contains a particular point of the vertical axis. This paper identifies a hidden assumption in this reverse Farkas lemma which always holds in its applications to nontrivial optimization problems. Moreover, it shows that the statement remains valid when the Farkas-Minkowski constraint qualification fails by replacing the mentioned set by its closure. This hidden assumption is also characterized in terms of the data. Finally, the paper provides some applications to convex infinite systems and to convex infinite optimization problems.Comment: 0 figure

Thermal Management of a Soft Starter: Transient Thermal Impedance Model and Performance Enhancements using Phase Change Materials

Adverse effects of starting-torque transients and high in-rush currents in induction motors are typically mitigated by employing electronically controlled soft starting voltages through silicon-controlled rectifiers (SCRs). However, the heat dissipation in the soft starter must be carefully managed in the design of motor drives. The objective of this study is both to address the heat dissipation in the soft starter by implementing analytical solutions to the heat diffusion equations inside the soft starter, and to investigate the use of a phase change material (PCM) based heat sink for thermal management of the device. The analytical modeling approach is, however, general, and can be applied to the solution of a range of thermal problems in power electronics. The transient analytical thermal model, based on the thermal quadrupole approach, allows a determination of the transient performance of a soft starter by evaluating the thyristor junction temperature. Predictions from the model are first compared to results obtained using a coupled thermal and electricalmodel based on a resistance/capacitance network approach. Experimental results obtained with the soft starter connected to a low-voltage 200 hp induction machine are then used to validate the model. Additionally, the performance improvement resulting from the use of a hybrid heat sink (plate fin heat sink immersed in a PCM) is evaluated and compared to a conventional air-cooled heat sink without a PCM under identical conditions

When some variational properties force convexity

Abstract The notion of adequate (resp. strongly adequate) function has been recently introduced to characterize the essentially strictly convex (resp. essentially firmly subdifferentiable) functions among the weakly lower semicontinuous (resp. lower semicontinuous) ones. In this paper we provide various necessary and sufficient conditions in order that the lower semicontinuous hull of an extended real-valued function on a reflexive Banach space is essentially strictly convex. Some new results on nearest (farthest) points are derived from this approach. keywords Convex duality, well posed optimization problem, essential strict convexity, essential smoothness, best approximation

Nuclear receptor coactivator/coregulator NCoA6(NRC) is a pleiotropic coregulator involved in transcription, cell survival, growth and development

NCoA6 (also referred to as NRC, ASC-2, TRBP, PRIP and RAP250) was originally isolated as a ligand-dependent nuclear receptor interacting protein. However, NCoA6 is a multifunctional coregulator or coactivator necessary for transcriptional activation of a wide spectrum of target genes. The NCoA6 gene is amplified and overexpressed in breast, colon and lung cancers. NCoA6 is a 250 kDa protein which harbors a potent N-terminal activation domain, AD1; and a second, centrally-located activation domain, AD2, which is necessary for nuclear receptor signaling. The intrinsic activation potential of NCoA6 is regulated by its C-terminal STL regulatory domain. Near AD2 is an LxxLL-1 motif which interacts with a wide spectrum of ligand-bound NRs with high-affinity. A second LxxLL motif (LxxLL-2) located towards the C-terminal region is more restricted in its NR specificity. The potential role of NCoA6 as a co-integrator is suggested by its ability to enhance transcriptional activation of a wide variety of transcription factors and from its in vivo association with a number of known cofactors including CBP/p300. NCoA6 has been shown to associate with at least three distinct coactivator complexes containing Set methyltransferases as core polypeptides. The composition of these complexes suggests that NCoA6 may play a fundamental role in transcriptional activation by modulating chromatin structure through histone methylation. Knockout studies in mice suggest that NCoA6 is an essential coactivator. NCoA6-/- embryos die between 8.5-12.5 dpc from general growth retardation coupled with developmental defects in the heart, liver, brain and placenta. NCoA6-/- MEFs grow at a reduced rate compared to WT MEFs and spontaneously undergo apoptosis, indicating the importance of NCoA6 as a prosurvival and anti-apoptotic gene. Studies with NCoA6+/- and conditional knockout mice suggest that NCoA6 is a pleiotropic coregulator involved in growth, development, wound healing and maintenance of energy homeostasis