The relationship between participation in professional development and level of social capital

The purpose of this study was to determine if a relationship exists between level of social capital and the extent of participation in professional development activities for professional employees of a profit-based organization located in the Southeastern United States. The researcher used survey methodology to determine the extent of participation in professional development activities within a 12 month period and the level of social capital within an organizational setting. Multiple regression analyses were conducted to determine if a model exists to explain a significant portion of the variance in the extent of participation in professional development activities from selected demographic variables and level of social capital. One key conclusion is that the study participants engaged in more self-initiated activities than any other type of professional development activity. Self-initiated activities include such activities as searching the internet for work-related information and seeking work-related information from a mentor or colleague. A second conclusion is that social capital was found to be a significant predictor of participation in voluntary professional development activities that were in individual settings. This second conclusion addresses the recent emphasis on the need to study social networks in order to understand participation in learning activities (Hatala, 2006). In addressing this need, the conclusion helps to bridge a gap in human resource development literature by increasing the understanding of the role of social capital in participation in professional development activities. Given that individual activities include one-on-one collaborations with mentors/colleagues, it is recommended that human resource development professionals include mentoring and relationship building in employee development plans to encourage the use of one-on-one contacts to support the acquisition of work-related information

Collapse dynamics of smectic-A bubbles

The collapse dynamics of smectic-A bubbles are analyzed experimentally and theoretically. Each bubble is expanded from a flat film stretched at the end of a hollow cylinder and deflated through a pressure release by means of a capillary tube. Its total collapse time can be varied between 0.1s and 20s by suitably choosing the length and the internal diameter of the capillary. This experiment allowed us to show that the collapse takes place in two steps: an initial one, which lasts a fraction of a second, where the meniscus destabilizes and fills up with focal conics, followed by a much longer period during which the bubble collapses and exchanges material with the meniscus. By measuring simultaneously the Laplace pressure and the internal pressure inside the bubble, we were able to fully characterize the shear-thinning behavior of the smectic phase within the meniscus. We emphasize that this method is generic and could be applied as well to other systems such as soap bubbles, on condition that inertial effects are negligible

Evaluation of knowledge transfer in an immersive virtual learning environment for the transportation community

In the year 2009, 667 individuals lost their lives in a highway construction or maintenance work zone (National Work Zone Safety Information Clearinghouse, 2010). Since the year 2003, 6,438 individuals have been killed in a highway construction or maintenance work zone, which is approximately 805 deaths per calendar year (National Work Zone Safety Information Clearinghouse, 2010). This eye-opening and unfortunate statistic points to the need for a re-evaluation of training methodology as it relates to work zone safety. This study reports on the use of virtual learning technology for work-zone training. This research tested the use of an Immersive Virtual Learning Environment (IVLE) simulating real-world highway work zones. IVLEs go beyond traditional visual learning by presenting images that combine a new form of visual learning and virtual-experiential learning in a way that is more congruent with an individual’s visual images stored in memory, thus improving knowledge transfer and retention (Dede, 2000; Kapp & O’Driscoll, 2010). The visual cues that the learner experiences in the virtual world are so similar to the visual cues in the real world that recall of virtual world lessons stored in memory are triggered by the same cues in the real world. Additionally, the student can experiment, make mistakes, and repeat the activity as often as necessary, achieving a virtual-experiential understanding of the concept that can only be duplicated in real-world experiential learning, which is often not practical (Dede, 2000; Kapp & O’Driscoll, 2010). Such immersive engagement in the learning activity will allow the learners to move beyond the memorization of the presented concepts and into the application and synthesis of the material. A significant benefit of this research will be a better understanding of how educators can implement this advanced, user-friendly, semi-transparent technology to positively affect the inclusion of marginalized populations into virtual learning environments. This research will establish a solid theoretical and evidence-based link between use of the virtual world learning environment and improved knowledge transfer and retention for that marginalized population that forms the bulk of the employment pool for military, construction, maintenance, and many other industrial entry-level positions

Identification of a strong contamination source for graphene in vacuum systems

To minimize parasitic doping effects caused by uncontrolled material adsorption, graphene is often investigated under vacuum. Here we report an entirely unexpected phenomenon occurring in vacuum systems, namely strong n-doping of graphene due to chemical species generated by common ion high-vacuum gauges. The effect --reversible upon exposing graphene to air-- is significant, as doping rates can largely exceed 10^{12} cm^{-2}/hour, depending on pressure and the relative position of the gauge and the graphene device. It is important to be aware of the phenomenon, as its basic manifestation can be mistakenly interpreted as vacuum-induced desorption of p-dopants.Comment: 10 pages, 4 figure

Observation of negative line tensions from Plateau border regions in dry foam films

International audienceWe measure the angles produced in the Plateau border region of " dry " soap films. In a simple experimental geometry, we demonstrate that a negative line tension can be attributed to these regions. This result has important consequences for the theoretical description of foams approaching the dry limit

Effets modulateurs du diabète, de l'obésité et de la génétique sur l'électrophysiologie des médicaments prolongeant l'intervalle QT

Le cycle régulier des contractions des oreillettes, suivi par des contractions ventriculaires, pompe le sang de manière efficace à travers le coeur. Par contre, lorsque le fin équilibre qui régule le mécanisme est débalancé, les arythmies peuvent s'installer. Parmi les multiples facteurs qui peuvent affecter l'équilibre électrophysiologique cardiaque, il faut noter une maladie métabolique dont la prévalence ne cesse d'augmenter dans la population mondiale : le diabète de type 2. En effet, cette maladie augmente les risques de souffrir d'arythmie. Nous avons d'abord développé un modèle de cobaye diabétique de type 2 par une alimentation avec une diète spéciale sur une période de 200 jours. Ces animaux nous ont permis d'obtenir nos résultats dans des conditions ex- et in-vivo. Par la suite, nous avons évalué une hypothèse selon laquelle, en présence de diabète, l'ajout d'un bloquant d'IcaL évite la prolongation excessive du QT et la pro-arythmie, lorsque d'autres médicaments prolongeant le QT sont utilisés de manière concomitante. Nous avons quantifié l'effet de l'amlodipine (Norvasc®), un médicament bloquant d'IcaL et du dofétilide (Tikosyn®), un médicament bloquant d'iKr- Les résultats obtenus ont montré que l'amlodipine renverse partiellement l'effet pro-arythmique du dofétilide et protège contre la prolongation excessive de l'intervalle QT et la pro-arythmie médicamenteuse, particulièrement en présence de diabète de type 2. En parallèle, nous avons qualifié et quantifié l'effet pro-arythmique du bupropion (Wellbutrin®, Zyban®), un antidépresseur et adjuvant à la cessation tabagique. Des élargissements du QRS avaient été rapportés lors de surdosages de bupropion. Nous avons voulu vérifier l'hypothèse selon laquelle le bupropion affecte la conduction cardiaque par un bloc des jonctions gap. À l'aide des résultats obtenus, nous avons pu dire que, contrairement aux anti-arythmiques de classe I, le bupropion n'élargit pas le QRS en bloquant IN3, mais plutôt en inhibant les jonctions gap. C'est une propriété pharmacologique exceptionnelle observée chez aucun autre médicament actuellement disponible sur le marché. L'élargissement du QRS et les troubles de conduction cardiaques s'observent à des concentrations de bupropion facilement atteignables en clinique

Multiple sclerosis susceptibility alleles in African Americans.

Multiple sclerosis (MS) is an autoimmune demyelinating disease characterized by complex genetics and multifaceted gene-environment interactions. Compared to whites, African Americans have a lower risk for developing MS, but African Americans with MS have a greater risk of disability. These differences between African Americans and whites may represent differences in genetic susceptibility and/or environmental factors. SNPs from 12 candidate genes have recently been identified and validated with MS risk in white populations. We performed a replication study using 918 cases and 656 unrelated controls to test whether these candidate genes are also associated with MS risk in African Americans. CD6, CLEC16a, EVI5, GPC5, and TYK2 contained SNPs that are associated with MS risk in the African American data set. EVI5 showed the strongest association outside the major histocompatibility complex (rs10735781, OR=1.233, 95% CI=1.06-1.43, P-value=0.006). In addition, RGS1 seems to affect age of onset whereas TNFRSF1A seems to be associated with disease progression. None of the tested variants showed results that were statistically inconsistent with the effects established in whites. The results are consistent with shared disease genetic mechanisms among individuals of European and African ancestry

Copy number variation in African Americans

<p>Abstract</p> <p>Background</p> <p>Copy number variants (CNVs) have been identified in several studies to be associated with complex diseases. It is important, therefore, to understand the distribution of CNVs within and among populations. This study is the first report of a CNV map in African Americans.</p> <p>Results</p> <p>Employing a SNP platform with greater than 500,000 SNPs, a first-generation CNV map of the African American genome was generated using DNA from 385 healthy African American individuals, and compared to a sample of 435 healthy White individuals. A total of 1362 CNVs were identified within African Americans, which included two CNV regions that were significantly different in frequency between African Americans and Whites (17q21 and 15q11). In addition, a duplication was identified in 74% of DNAs derived from cell lines that was not present in any of the whole blood derived DNAs.</p> <p>Conclusion</p> <p>The Affymetrix 500 K array provides reliable CNV mapping information. However, using cell lines as a source of DNA may introduce artifacts. The duplication identified in high frequency in Whites and low frequency in African Americans on chromosome 17q21 reflects haplotype specific frequency differences between ancestral groups. The generation of the CNV map will be a valuable tool for identifying disease associated CNVs in African Americans.</p