3,365 research outputs found

    Optical fluid and biomolecule transport with thermal fields

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    A long standing goal is the direct optical control of biomolecules and water for applications ranging from microfluidics over biomolecule detection to non-equilibrium biophysics. Thermal forces originating from optically applied, dynamic microscale temperature gradients have shown to possess great potential to reach this goal. It was demonstrated that laser heating by a few Kelvin can generate and guide water flow on the micrometre scale in bulk fluid, gel matrices or ice without requiring any lithographic structuring. Biomolecules on the other hand can be transported by thermal gradients, a mechanism termed thermophoresis, thermal diffusion or Soret effect. This molecule transport is the subject of current research, however it can be used to both characterize biomolecules and to record binding curves of important biological binding reactions, even in their native matrix of blood serum. Interestingly, thermophoresis can be easily combined with the optothermal fluid control. As a result, molecule traps can be created in a variety of geometries, enabling the trapping of small biomolecules, like for example very short DNA molecules. The combination with DNA replication from thermal convection allows us to approach molecular evolution with concurrent replication and selection processes inside a single chamber: replication is driven by thermal convection and selection by the concurrent accumulation of the DNA molecules. From the short but intense history of applying thermal fields to control fluid flow and biological molecules, we infer that many unexpected and highly synergistic effects and applications are likely to be explored in the future

    The effects of stereotypes of women's performance in male-dominated hierarchies: Stereotype threat activation and reduction through role models

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    Despite recent progress in increasing gender equality in organizations, workplace hierarchies remain male-dominated in most domains. We discuss how gender stereotypes contribute to holding women back in leadership and workplace domains and how we can reduce the negative effects of gender stereotypes. In the first part of the chapter we discuss how awareness of negative stereotypes of women in leadership can decrease women's performance and self-related cognitions in leadership tasks such as motivating employees, managerial decision-making, and negotiating. In the second part of the chapter we discuss effective strategies to reduce the negative effects of stereotypes. We particularly focus on the strategy of exposing women to counterstereotypic exemplars - women who succeeded, thus disproving the stereotype. Given that exposures to successful women can have both threatening and inspiring effects, we propose a model which discusses the conditions under which successful female role models would inspire women with leadership aspirations

    Nonverbal communication in health settings

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    The goal of the present chapter is to provide an overview of the existing literature on nonverbal communication in the medical encounter. After introducing the different functions of nonverbal behavior and its importance in the medical context, we present empirical evidence showing how physician nonverbal behavior relates to different patient outcomes such as satisfaction, trust, or adherence. We then present different models and assessment tools with which nonverbal behavior in the medical encounter can be studied. The physician's ability to pick up and correctly interpret the patient's nonverbal cues (interpersonal sensitivity) and its impact on patient outcomes will be reviewed. We close the chapter by providing a summary of the main results and an outlook on open questions in the field

    Gender in patient-physician interactions

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    Female leaders are typically evaluated less favorably than their male counterparts. Since physicians are perceived as being high in status and power just like leaders, we propose to examine to what extent female doctors are affected by the same evaluations as female leaders in general. We present a review of the literature showing how the sex of the physician and the patient, as well as the sex composition of the physician-patient dyad affect the interaction behaviour of physicians and patients during the medical interaction and the interaction outcomes. Moreover, there are differences in how female and male doctors are perceived and evaluated by their patients and both of these aspects affect consultation outcomes. We examine how gender stereotypes can explain those differences of perception and evaluation of male and female physicians

    Microstability analysis of pellet fuelled discharges in MAST

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    Reactor grade plasmas are likely to be fuelled by pellet injection. This technique transiently perturbs the profiles, driving the density profile hollow and flattening the edge temperature profile. After the pellet perturbation, the density and temperature profiles relax towards their quasi-steady-state shape. Microinstabilities influence plasma confinement and will play a role in determining the evolution of the profiles in pellet fuelled plasmas. In this paper we present the microstability analysis of pellet fuelled H-mode MAST plasmas. Taking advantage of the unique capabilities of the MAST Thomson scattering system and the possibility of synchronizing the eight lasers with the pellet injection, we were able to measure the evolution of the post-pellet electron density and temperature profiles with high temporal and spatial resolution. These profiles, together with ion temperature profiles measured using a charge exchange diagnostic, were used to produce equilibria suitable for microstability analysis of the equilibrium changes induced by pellet injection. This analysis, carried out using the local gyrokinetic code GS2, reveals that the microstability properties are extremely sensitive to the rapid and large transient excursions of the density and temperature profiles, which also change collisionality and beta e significantly in the region most strongly affected by the pellet ablation.Comment: 21 pages, 10 figures. This is an author-created, un-copyedited version of an article submitted for publication in Plasma Physics and Controlled Fusion. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from i

    Beyond "one size fits all": Physician nonverbal adaptability to patients' need for paternalism and its positive consultation outcomes

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    In this study, we tested whether physicians' ability to adapt their nonverbal behavior to their patients' preferences for a paternalistic interaction style is related to positive consultation outcomes. We hypothesized that the more physicians adapt their nonverbal dominance behavior to match their patients' preferences for physician paternalism, the more positive the patients perceive the medical interaction. We assessed the actual nonverbal dominance behavior of 32 general practitioners when interacting with two of their patients and compared it with each of their patients' preferences for paternalism to obtain a measure of adaptability. Additionally, we measured patient outcomes with a questionnaire assessing patient satisfaction, trust in the physician, and evaluation of physician competence. Results show that the more nonverbal dominance the physician shows towards the patient who prefers a more paternalistic physician, as compared to towards the patient who prefers a less paternalistic physician (i.e., the more the physician shows nonverbal behavioral adaptability), the more positive the consultation outcomes are. This means that physicians' ability to adapt aspects of their nonverbal dominance behavior to their individual patients' preferences is related to better outcomes for patients. As this study shows, it is advantageous for patients when a physician behaves flexibly instead of showing the same behavior towards all patients. Physician training might want to focus more on teaching a diversity of different behavior repertoires instead of a given set of behaviors

    Street crossing behavior in younger and older pedestrians: an eye- and head-tracking study

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    Background Crossing a street can be a very difficult task for older pedestrians. With increased age and potential cognitive decline, older people take the decision to cross a street primarily based on vehicles’ distance, and not on their speed. Furthermore, older pedestrians tend to overestimate their own walking speed, and could not adapt it according to the traffic conditions. Pedestrians’ behavior is often tested using virtual reality. Virtual reality presents the advantage of being safe, cost-effective, and allows using standardized test conditions. Methods This paper describes an observational study with older and younger adults. Street crossing behavior was investigated in 18 healthy, younger and 18 older subjects by using a virtual reality setting. The aim of the study was to measure behavioral data (such as eye and head movements) and to assess how the two age groups differ in terms of number of safe street crossings, virtual crashes, and missed street crossing opportunities. Street crossing behavior, eye and head movements, in older and younger subjects, were compared with non-parametric tests. Results The results showed that younger pedestrians behaved in a more secure manner while crossing a street, as compared to older people. The eye and head movements analysis revealed that older people looked more at the ground and less at the other side of the street to cross. Conclusions The less secure behavior in street crossing found in older pedestrians could be explained by their reduced cognitive and visual abilities, which, in turn, resulted in difficulties in the decision-making process, especially under time pressure. Decisions to cross a street are based on the distance of the oncoming cars, rather than their speed, for both groups. Older pedestrians look more at their feet, probably because of their need of more time to plan precise stepping movement and, in turn, pay less attention to the traffic. This might help to set up guidelines for improving senior pedestrians’ safety, in terms of speed limits, road design, and mixed physical-cognitive trainings
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