Exploring barriers in expertise seeking : why don\u27t they ask an expert?

This paper reports findings from a research project that explores reasons why some employees prefer to seek expertise to resolve work-related problems from direct colleagues rather than designated internal experts. Several studies suggest that while an expert generally provides a higher quality solution in a shorter time, workers tend to ask friendly or proximate colleagues to help with knowledge-based problems at work. Prior research provides only fragmented insights into understanding the barriers to asking a designated internal expert for help at work. To address this gap, we asked post-graduate students enrolled in a knowledge management subject at a large Australian university to share their perspectives in an online discussion forum. Content analysis of the collected perspectives enabled identification of twenty-one factors that may limit the seeking of expertise from a designated internal expert. The factors are grouped in four categories: environment, accessibility, communication and personality. In addition one context variable is described, determining the extent to which the barriers are influential in a specific situation. By synthesising the results, we have proposed two models of expertise-seeking barriers. A literature review helps validate the barriers identified by the study. Key theoretical and practical implications are also discussed.<br /

Modeling the ballistic-to-diffusive transition in nematode motility reveals variation in exploratory behavior across species

A quantitative understanding of organism-level behavior requires predictive models that can capture the richness of behavioral phenotypes, yet are simple enough to connect with underlying mechanistic processes. Here we investigate the motile behavior of nematodes at the level of their translational motion on surfaces driven by undulatory propulsion. We broadly sample the nematode behavioral repertoire by measuring motile trajectories of the canonical lab strain $C. elegans$ N2 as well as wild strains and distant species. We focus on trajectory dynamics over timescales spanning the transition from ballistic (straight) to diffusive (random) movement and find that salient features of the motility statistics are captured by a random walk model with independent dynamics in the speed, bearing and reversal events. We show that the model parameters vary among species in a correlated, low-dimensional manner suggestive of a common mode of behavioral control and a trade-off between exploration and exploitation. The distribution of phenotypes along this primary mode of variation reveals that not only the mean but also the variance varies considerably across strains, suggesting that these nematode lineages employ contrasting ``bet-hedging'' strategies for foraging.Comment: 46 pages, 18 figures, 6 table

Response of selected microorganisms to experimental planetary environments

The anaerobic utilization of phosphite or phosphine and the significance of this conversion to potential contamination of Jupiter were investigated. A sporeforming organism was isolated from Cape Canaveral soil which anaerobically converts hypophosphite to phosphate. This conversion coincides with an increase in turbidity of the culture and with phosphate accumulation in the medium. Investigations of omnitherms (organisms which grow over a broad temperature range, i.e. 3 -55 C were also conducted. The cellular morphology of 28 of these isolates was investigated, and all were demonstrated to be sporeformers. Biochemical characterizations are also presented. Procedures for replicate plating were evaluated, and those results are also presented. The procedures for different replicate-plating techniques are presented, and these are evaluated on the basis of reproducibility, percentage of viable transfer, and ease of use. Standardized procedures for the enumeration of microbial populations from ocean-dredge samples from Cape Canaveral are also presented

The influence of anesthetics, neurotransmitters and antibiotics on the relaxation processes in lipid membranes

In the proximity of melting transitions of artificial and biological membranes fluctuations in enthalpy, area, volume and concentration are enhanced. This results in domain formation, changes of the elastic constants, changes in permeability and slowing down of relaxation processes. In this study we used pressure perturbation calorimetry to investigate the relaxation time scale after a jump into the melting transition regime of artificial lipid membranes. This time corresponds to the characteristic rate of domain growth. The studies were performed on single-component large unilamellar and multilamellar vesicle systems with and without the addition of small molecules such as general anesthetics, neurotransmitters and antibiotics. These drugs interact with membranes and affect melting points and profiles. In all systems we found that heat capacity and relaxation times are related to each other in a simple manner. The maximum relaxation time depends on the cooperativity of the heat capacity profile and decreases with a broadening of the transition. For this reason the influence of a drug on the time scale of domain formation processes can be understood on the basis of their influence on the heat capacity profile. This allows estimations of the time scale of domain formation processes in biological membranes.Comment: 12 pages, 6 figure

Mechanisms of Hemolysis-Associated Platelet Activation

Background Intravascular hemolysis occurs after blood transfusion, in hemolytic anemias, and in other conditions, and is associated with hypercoagulable states. Hemolysis has been shown to potently activate platelets in vitro and in vivo, and several mechanisms have been suggested to account for this, including: (i) direct activation by hemoglobin (Hb); (ii) increase in reactive oxygen species (ROS); (iii) scavenging of nitric oxide (NO) by released Hb; and (iv) release of intraerythrocytic ADP. Objective To elucidate the mechanism of hemolysis-mediated platelet activation. Methods We used flow cytometry to detect PAC-1 binding to activated platelets for in vitro experiments, and a Siemens\u27 Advia 120 hematology system to assess platelet aggregation by using platelet counts from in vivo experiments in a rodent model. Results We found that Hb did not directly activate platelets. However, ADP bound to Hb could cause platelet activation. Furthermore, platelet activation caused by shearing of red blood cells (RBCs) was reduced in the presence of apyrase, which metabolizes ADP to AMP. The use of ROS scavengers did not affect platelet activation. We also found that cell-free Hb enhanced platelet activation by abrogating the inhibitory effect of NO on platelet activation. In vivo infusions of ADP and purified (ADP-free) Hb, as well as hemolysate, resulted in platelet aggregation, as shown by decreased platelet counts. Conclusion Two primary mechanisms account for RBC hemolysis-associated platelet activation: ADP release, which activates platelets; and cell-free Hb release, which enhances platelet activation by lowering NO bioavailability

Drawing the Line: How African, Caribbean and White British Women Live Out Psychologically Abusive Experiences

The final, definitive version of this paper has been published in Violence Against Women, 19 (9):1104-32, Sept 2013 by SAGE Publications Ltd, All rights reserved. © The Author(s) 2013. The online version of this article can be found at: http://vaw.sagepub.com/content/19/9/110

Morphology and Interaction between Lipid Domains

Cellular membranes are a heterogeneous mix of lipids, proteins and small molecules. Special groupings of saturated lipids and cholesterol form a liquid-ordered phase, known as `lipid rafts,' serving as platforms for signaling, trafficking and material transport throughout the secretory pathway. Questions remain as to how the cell maintains heterogeneity of a fluid membrane with multiple phases, through time, on a length-scale consistent with the fact that no large-scale phase separation is observed. We have utilized a combination of mechanical modeling and in vitro experiments to show that membrane morphology can be a key player in maintaining this heterogeneity and organizing such domains in the membrane. We demonstrate that lipid domains can adopt a flat or dimpled morphology, where the latter facilitates a repulsive interaction that slows coalescence and tends to organize domains. These forces, that depend on domain morphology, play an important role in regulating lipid domain size and in the lateral organization of lipids in the membrane.Comment: 7 pages, 4 figure

Are different groups of patients with stroke more likely to be excluded from the new UK general medical services contract? A cross-sectional retrospective analysis of a large primary care population

Peer reviewedPublisher PD

Shifting Winds: Using Ancestry DNA to Explore Multiracial Individuals\u27 Patterns of Articulating Racial Identity

This study explored how genotype information affects identification narratives of multiracial individuals. Twenty-one multiracial individuals completed individual interviews before and after receiving a DNA analysis to clarify their genetically based racial ancestry. Based on results, this article proposes patterns of articulating racial identity by multiracial individuals. Four patterns extend evolving research in multiracial identification, namely (1) the individual articulates a monoracial identity; (2) the individual articulates one identity, but this can shift in response to various conditions; (3) the individual articulates an extraracial identity, opting out of traditional categories applied to race; and (4) the person distinguishes traditional categories of race from culture and owns the two identities in different ways. Implications of these findings are discussed. First, adding new ancestry DNA information further muddles the neat categories of race, consistent with the view of race as socially constructed. Second, results emphasize the fluidity of identification for multiracial individuals. Third, DNA information challenges the neat percentages people tend to associate with their backgrounds. Particularly for younger multiracial individuals, there was less of a sense that race was a real thing and more that culture played a big part in how they saw themselves