554 research outputs found

    Robust FDI Determinants: Bayesian Model Averaging In The Presence Of Selection Bias

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    The literature on Foreign Direct Investment (FDI) determinants is remarkably diverse in terms of competing theories and empirical results. We utilize Bayesian Model Averaging (BMA) to resolve the model uncertainty that surrounds the validity of the competing FDI theories. Since the structure of existing FDI data is known to induce selection bias, we extend BMA theory to HeckitBMA to address model uncertainty in the presence of selection bias. We then show that more than half of the previously suggested FDI determinants are no longer robust and highlight theories that receive support from the data. In addition, our selection approach allows us to highlight that the determinants of margins of FDI (intensive and extensive) differ profoundly in the data, while FDI theories do not usually model this aspect explicitly.

    The Effect Of Problem Based Learning On Undergraduate Oral Communication Competency

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    Purpose:  The aim of this study was to ascertain the effect of Problem Based Learning (PBL) on student oral communication competency gains. Methods:  Eighty students from two consecutive undergraduate Kinesiology courses (Spring semesters, 2014-15) formed into 29 small groups and were studied.  Oral communication competency was assessed using a customized rubric and digital recordings of student presentations.  Changes to oral communication competency across time were tested using a dependent t-test; a < .05. Results:  Significant inter-rater agreement was found at both time points for oral communication rating, and student groups demonstrated significant oral communication gains across time.  Conclusions:  Collaborative learning was shown to improve students’ oral communication competency. Future study is required to determine the influence of student motivation and goal orientation on oral communication competency, in relation to the various phases of knowledge creation occurring within student groups.

    Everybody in and nobody out : opportunities, narrative, and the radical flank in the movement for single-payer health care reform

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    Title from PDF of title page (University of Missouri--Columbia, viewed on August 29, 2012).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Dissertation advisor: Dr. Clarence LoIncludes bibliographical references.Vita.Ph. D. University of Missouri--Columbia 2012"May 2012"In this dissertation, I analyze over twenty years of the United States Single Payer Movement. I began this analysis with the following questions in mind -- What is the Relationship between opportunity and grassroots mobilization? How do activists understand opportunity? What is the role of narrative in this process? I grounded my analysis in a feminist epistemological and methodological stance, which is rooted in the understanding that all knowledge is located and that we can learn much by privileging the voices from marginalized positions. This research involved participant observation, semi-structured interviews, and content analysis. This research has resulted in a significant contribution to social movement theory by further explicating the relationship between opportunity and grassroots opportunity. I argue that social movement actors develop understandings about the opportunities that they face through the practice of narrative. This narrative practice is an integral aspect in the process of pragmatic liberation, or the practice of liberation, through which social movement actors seek to empower themselves and a wider audience of constituents. Even during time periods in which there is less political likelihood that the movement will achieve its goals, movement activists are able to mobilize constituencies by constructing narratives of opportunity outside of the material realm. A more diverse system of narrative practice that is rooted in multiple types of opportunity facilitates greater diversity in movement mobilization.Includes bibliographical reference

    Techniques for targeted Fermi-GBM follow-up of gravitational-wave events

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    The Advanced LIGO and Advanced Virgo ground-based gravitational-wave detectors are projected to come online 2015-2016, reaching a final sensitivity sufficient to observe dozens of binary neutron star mergers per year by 2018. We present a fully-automated, targeted search strategy for prompt gamma-ray counterparts in offline Fermi-GBM data. The multi-detector method makes use of a detailed model response of the instrument, and benefits from time and sky location information derived from the gravitational-wave signal.Comment: 2012 Fermi Symposium proceedings - eConf C12102

    Closure statistics in interferometric data

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    Interferometric visibilities, reflecting the complex correlations between signals recorded at antennas in an interferometric array, carry information about the angular structure of a distant source. While unknown antenna gains in both amplitude and phase can prevent direct interpretation of these measurements, certain combinations of visibilities called closure phases and closure amplitudes are independent of antenna gains and provide a convenient set of robust observables. However, these closure quantities have subtle noise properties and are generally both linearly and statistically dependent. These complications have obstructed the proper use of closure quantities in interferometric analysis, and they have obscured the relationship between analysis with closure quantities and other analysis techniques such as self calibration. We review the statistics of closure quantities, noting common pitfalls that arise when approaching low signal-to-noise due to the nonlinear propagation of statistical errors. We then develop a strategy for isolating and fitting to the independent degrees of freedom captured by the closure quantities through explicit construction of linearly independent sets of quantities along with their noise covariance in the Gaussian limit, valid for moderate signal-to-noise, and we demonstrate that model fits have biased posteriors when this covariance is ignored. Finally, we introduce a unified procedure for fitting to both closure information and partially calibrated visibilities, and we demonstrate both analytically and numerically the direct equivalence of inference based on closure quantities to that based on self calibration of complex visibilities with unconstrained antenna gains.Comment: 31 pages, 17 figure

    Understanding pathogen transmission dynamics in waterbird communities: At what scale should interactions be studied?

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    Pathogen transmission in animal populations is contingent on interactions between and within species. Often standard ornithological data (e.g. total counts at a wetland) are the only data available for assessing the risks of avian pathogen transmission. In this paper we ask whether these data can be used to infer fine-scale transmission patterns. We tested for non-randomness in waterbird assemblages and explored waterbird interactions using social network analysis. Certain network parameter values were then compared to a data set on avian influenza prevalence in southern Africa. Our results showed that species associations were strongly non-random, implying that most standard ornithological data sets would not provide adequate information on which to base models of pathogen spread. In both aquatic and terrestrial networks, all species regularly associated closely with other network members. The spread of pathogens through the community could thus be rapid. Network analysis together with detailed, fine-scale observations offers a promising avenue for further research and management-oriented applications

    Does an empathic pre-visit conversation with another team member improve perceived surgeon empathy?

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    Orthopedic surgeon specialists can help alleviate symptoms and reduce self-reported activity limitations by addressing stress, distress, and unhelpful cognitive biases regarding pain (e.g., “hurt equals harm”). But noticing mental and social health opportunities in specialty care can harm the patient-surgeon relationship. This study evaluated the ability of an empathic pre-visit conversation by another team member to improve the patient-surgeon relationship measured as perceived empathy. Factors associated with pain intensity, magnitude of self-reported activity limitations, symptoms of depression, and satisfaction with the surgeon were also studied. We enrolled 100 patients visiting an orthopedic surgeon for the first time. Prior to the visit with the surgeon, 50 patients met with another team member and had a pre-visit discussion about a sense of purpose and meaning in life, availability of loving relationships, and things that elicit laughter—a discussion intended to honor what matters most to an individual—and the other 50 patients did not. At the end of the visit we recorded perceived surgeon empathy, pain intensity, magnitude of self-reported activity limitations, symptoms of depression, and satisfaction with the surgeon. The pre-visit discussion did not affect perceived surgeon empathy (p=0.81), pain intensity (p=0.75), magnitude of self-reported activity limitations (p=0.63), symptoms of depression (p=0.46), or satisfaction with the surgeon (p=0.79). Patient experience with a surgeon does not benefit from a positive milieu created by a non-surgeon team member. Future studies can address relationship-building tactics used by the surgeon. Experience Framework This article is associated with the Patient, Family & Community Engagement lens of The Beryl Institute Experience Framework. (http://bit.ly/ExperienceFramework) Access other PXJ articles related to this lens. Access other resources related to this lens

    Dynamical Imaging with Interferometry

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    By linking widely separated radio dishes, the technique of very long baseline interferometry (VLBI) can greatly enhance angular resolution in radio astronomy. However, at any given moment, a VLBI array only sparsely samples the information necessary to form an image. Conventional imaging techniques partially overcome this limitation by making the assumption that the observed cosmic source structure does not evolve over the duration of an observation, which enables VLBI networks to accumulate information as the Earth rotates and changes the projected array geometry. Although this assumption is appropriate for nearly all VLBI, it is almost certainly violated for submillimeter observations of the Galactic Center supermassive black hole, Sagittarius A* (Sgr A*), which has a gravitational timescale of only ~20 seconds and exhibits intra-hour variability. To address this challenge, we develop several techniques to reconstruct dynamical images ("movies") from interferometric data. Our techniques are applicable to both single-epoch and multi-epoch variability studies, and they are suitable for exploring many different physical processes including flaring regions, stable images with small time-dependent perturbations, steady accretion dynamics, or kinematics of relativistic jets. Moreover, dynamical imaging can be used to estimate time-averaged images from time-variable data, eliminating many spurious image artifacts that arise when using standard imaging methods. We demonstrate the effectiveness of our techniques using synthetic observations of simulated black hole systems and 7mm Very Long Baseline Array observations of M87, and we show that dynamical imaging is feasible for Event Horizon Telescope observations of Sgr A*.Comment: 16 Pages, 12 Figures, Accepted for publication in Ap

    Inhibitory Deficits, Delay Aversion and Preschool AD/HD: Implications for the Dual Pathway Model

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    The dual pathway model proposes the existence of separate and neurobiologically distinct cognitive (inhibitory and more general executive dysfunction) and motivational (delay aversion) developmental routes to AD/HD. The study reported in this paper explores the relation between inhibitory deficits and delay aversion and their association with AD/HD in a group of three-year-old children. Children identified as having a pre-school equivalent of AD/HD (N=19) and controls (N=19), matched for gender and IQ, completed a battery of inhibition and delay tasks. Correlational and factor analysis supported a dissociation between inhibitory deficits (go-no-go, set shifting) and delay aversion (choice delay) with delay of gratification cross-loading. Children with AD/HD displayed more inhibitory deficits and were more delay averse than controls. The data support the value of the distinction between motivational and cognitive pathways to AD/HD. Furthermore, the data suggest that such a distinction is apparent relatively early on during development
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