1,342 research outputs found

    Bridging the Great Divide Between Theoretical and Empirical Management Research

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    Management research places a great premium on theory development. Despite this emphasis, concerns have been expressed regarding the extent to which management theories are tested in empirical research. This article reviews evidence concerning the connections between theoretical and empirical management research and reports an investigation that examines the correspondence between the propositions presented in 20 highly cited theoretical articles and the hypotheses stated in 361 empirical articles that cite the theories. Results indicate that the vast majority of theoretical propositions are not translated into empirical hypotheses, indicating a great divide between theoretical and empirical management research. Implications of these results are discussed, and potential solutions are offered

    Arts-Driven Economic Development: The Use of Arts and Culture to Advance Urban Revitalization in Providence, Rhode Island and Durham, North Carolina

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    Given the increasing popularity of arts-based economic development strategies, this paper considers two cities, Providence, Rhode Island and Durham, North Carolina, in an effort to gain some new insight into how cities support and develop the arts as a component of urban revitalization efforts. A review of the relevant literature on the topic seeks to establish why the arts are considered a viable tool for economic development as well as the characteristics that define a successful artistic culture in cities. The subsequent section investigates the development of the arts in Providence throughout the 1980's and 1990's, which is commonly considered a textbook case in successful development of arts and culture as part of an equally successful urban revitalization process known as the Providence Renaissance. Generally speaking, the successful cultivation of a flourishing arts scene in Providence was the result of creative and ambitious efforts on the part of artists themselves in concert with dedicated stream of financial and regulatory support from the city government. Durham, by contrast, is in the early stages of a revitalization process and, while artists are working diligently to organize their community and claim a role in the process, the commitment of the government to emphasizing the arts as part of the larger revitalization has thus far been mixed. Recognizing the many differences between the two cases and the consequent limits on the ability to generalize from them, this paper concludes with a consideration of the lessons learned from Providence and Durham and establishes some basic prerequisites for winning arts-based revitalization strategies. Chief among these conclusions is that providing public sector support for programs initiated in the private sector is the most effective model for success.Master of City and Regional Plannin

    Will savings from biosimilars offset increased costs related to dose escalation? A comparison of infliximab and golimumab for rheumatoid arthritis

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    INTRODUCTION: Biosimilar infliximab has the potential for appreciable cost savings compared to its reference biologic, but dose escalation is common and increases costs. We compared frequency of dose escalation and associated Medicare-approved amount so as to determine the break-even point at which infliximab dose escalation would offset the cost savings of using a biosimilar, referent to alternatively using golimumab. METHODS: We studied Medicare enrollees with rheumatoid arthritis (RA) initiating infliximab or golimumab. Frequency of dose escalation was summarized descriptively over 18 months, as were Medicare-approved amounts for reimbursement. Analyses were repeated conditioning on high adherence (i.e., non-discontinuation, \u3e 10-week gap). Multivariable-adjusted logistic regression and mixed models evaluated factors associated with infliximab dose escalation. RESULTS: A total of 5174 infliximab and 2843 golimumab initiators were observed. Dose escalation was rare for golimumab (5%) but common for infliximab (49%), and was even more common (72%) for infliximab among patients who persisted on treatment. Regardless of dose escalation, the adjusted least square mean dollar amounts were appreciably higher for golimumab (28,146)thanforinfliximab(28,146) than for infliximab (21,216) and greater among persistent patients (cost difference $9269, favoring infliximab). Only when patients escalated infliximab to \u3e /= 8 mg/kg every 6 weeks was golimumab IV at break-even or less expensive. After controlling for multiple factors, physician ownership of the infusion center was associated with greater likelihood of infliximab dose escalation (odds ratio = 1.25, 95% CI 1.09-1.44). CONCLUSION: Despite frequent dose escalation with infliximab that often increase its dose by threefold or more, the savings from the current price of its biosimilar substantially offsets the costs of an alternative infused TNFi biologic for which no biosimilar is available

    System-Level Analysis of Alzheimer\u27s Disease Prioritizes Candidate Genes for Neurodegeneration.

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    Alzheimer\u27s disease (AD) is a debilitating neurodegenerative disorder. Since the advent of the genome-wide association study (GWAS) we have come to understand much about the genes involved in AD heritability and pathophysiology. Large case-control meta-GWAS studies have increased our ability to prioritize weaker effect alleles, while the recent development of network-based functional prediction has provided a mechanism by which we can use machine learning to reprioritize GWAS hits in the functional context of relevant brain tissues like the hippocampus and amygdala. In parallel with these developments, groups like the Alzheimer\u27s Disease Neuroimaging Initiative (ADNI) have compiled rich compendia of AD patient data including genotype and biomarker information, including derived volume measures for relevant structures like the hippocampus and the amygdala. In this study we wanted to identify genes involved in AD-related atrophy of these two structures, which are often critically impaired over the course of the disease. To do this we developed a combined score prioritization method which uses the cumulative distribution function of a gene\u27s functional and positional score, to prioritize top genes that not only segregate with disease status, but also with hippocampal and amygdalar atrophy. Our method identified a mix of genes that had previously been identified in AD GWAS including APOE, TOMM40, and NECTIN2(PVRL2) and several others that have not been identified in AD genetic studies, but play integral roles in AD-effected functional pathways including IQSEC1, PFN1, and PAK2. Our findings support the viability of our novel combined score as a method for prioritizing region- and even cell-specific AD risk genes

    Kepler Presearch Data Conditioning II - A Bayesian Approach to Systematic Error Correction

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    With the unprecedented photometric precision of the Kepler Spacecraft, significant systematic and stochastic errors on transit signal levels are observable in the Kepler photometric data. These errors, which include discontinuities, outliers, systematic trends and other instrumental signatures, obscure astrophysical signals. The Presearch Data Conditioning (PDC) module of the Kepler data analysis pipeline tries to remove these errors while preserving planet transits and other astrophysically interesting signals. The completely new noise and stellar variability regime observed in Kepler data poses a significant problem to standard cotrending methods such as SYSREM and TFA. Variable stars are often of particular astrophysical interest so the preservation of their signals is of significant importance to the astrophysical community. We present a Bayesian Maximum A Posteriori (MAP) approach where a subset of highly correlated and quiet stars is used to generate a cotrending basis vector set which is in turn used to establish a range of "reasonable" robust fit parameters. These robust fit parameters are then used to generate a Bayesian Prior and a Bayesian Posterior Probability Distribution Function (PDF) which when maximized finds the best fit that simultaneously removes systematic effects while reducing the signal distortion and noise injection which commonly afflicts simple least-squares (LS) fitting. A numerical and empirical approach is taken where the Bayesian Prior PDFs are generated from fits to the light curve distributions themselves.Comment: 43 pages, 21 figures, Submitted for publication in PASP. Also see companion paper "Kepler Presearch Data Conditioning I - Architecture and Algorithms for Error Correction in Kepler Light Curves" by Martin C. Stumpe, et a

    Ariel - Volume 4 Number 3

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    Editors David A. Jacoby Eugenia Miller Tom Williams Associate Editors Paul Bialas Terry Burt Michael Leo Gail Tenikat Editor Emeritus and Business Manager Richard J. Bonnano Movie Editor Robert Breckenridge Staff Richard Blutstein Mary F. Buechler Steve Glinks Len Grasman Alice M. Johnson J.D. Kanofsky Tom Lehman Dave Mayer Bernie Odd

    Intestinal fibrosis is reduced by early elimination of inflammation in a mouse model of IBD: Impact of a ā€œTopā€Downā€ approach to intestinal fibrosis in mice

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    Background: The natural history of Crohn's disease follows a path of progression from an inflammatory to a fibrostenosing disease, with most patients requiring surgical resection of fibrotic strictures. Potent antiinflammatory therapies reduce inflammation but do not appear to alter the natural history of intestinal fibrosis. The aim of this study was to determine the relationship between intestinal inflammation and fibrogenesis and the impact of a very early ā€œtopā€downā€ interventional approach on fibrosis in vivo. Methods: In this study we removed the inflammatory stimulus from the Salmonella typhimurium mouse model of intestinal fibrosis by eradicating the S. typhimurium infection with levofloxacin at sequential timepoints during the infection. We evaluated the effect of this elimination of the inflammatory stimulus on the natural history of inflammation and fibrosis as determined by gross pathology, histopathology, mRNA expression, and protein expression. Results: Fibrogenesis is preceded by inflammation. Delayed eradication of the inflammatory stimulus by antibiotic treatment represses inflammation without preventing fibrosis. Early intervention significantly ameliorates but does not completely prevent subsequent fibrosis. Conclusions: This study demonstrates that intestinal fibrosis develops despite removal of an inflammatory stimulus and elimination of inflammation. Early intervention ameliorates but does not abolish subsequent fibrosis, suggesting that fibrosis, once initiated, is selfā€propagating, suggesting that a very early topā€down interventional approach may have the most impact on fibrostenosing disease. (Inflamm Bowel Dis 2012;)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90367/1/21812_ftp.pd

    The Most Important Current Research Questions in Urban Ecosystem Services

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    We tend to take natureā€™s ecological systems ā€“ or ecosystems ā€“ for granted, but they provide critically valuable services to society and to urban areas. They create a sense of place and recreational opportunities, contributing to quality of life by enhancing human physical and psychological health. This is particularly true for cities, where economic productivity, fiscal soundness, community life, and governance are tied to natural surroundings in distinct, unique and generally under-appreciated ways. Because the urbanized world depends on ecosystem services ā€“ both inside and outside of city boundaries ā€“ investing in the provision of ecosystem services will often be more cost-effective than response actions, such as treatment, restoration, and disaster response. Given the importance of urban ecosystem benefits to surrounding populations, we might expect that ecosystem services would play a prominent role in the formulation of urban policies, plans, and laws. However, with rare exception, they do not. Many cities are experiencing declines of the ecosystems that sustain them. Metropolitan areas are losing open space, farmland, and environmentally sensitive lands. As America, and indeed the rest of the world, becomes increasingly urbanized, these issues are of the first importance in seeking to improve quality of life. The scholarship in the area, though, has been fragmented by discipline. Much remains to be done. First and foremost, we must identify the pressing research needs. This article brings together the collective insights of scholars and practitioners from a wide range of disciplines ā€“ lawyers and urban planners to ecologists and economists. Taking a comprehensive and wide-ranging view of the field, we identify the most important research questions that should shape the future of scholarship on urban ecosystem services. In doing so, we seek to help shape the trajectory of research across multiple disciplines in this growing and critical area

    Level of clinical evidence presented at the open and closed American Shoulder and Elbow Surgeons annual meeting over 10 years (2005-2014)

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    Ā© 2016 The Author(s). Background: The American Shoulder and Elbow Surgeons (ASES) annual scientific meetings are premier forums whereby orthopaedic surgeons are informed of the latest research advances in shoulder and elbow surgery. The purpose of the present study was to assess the Level of evidence (LOE) in the clinical papers presented at both the open and closed ASES annual scientific meetings from 2005 to 2014. Secondarily, the study evaluated whether there were any changes in the distribution of LOE over this period of time. Methods: Two reviewers independently evaluated the abstracts of 532 paper presentations at either the open or closed ASES annual meetings. The independent reviewers first screened the abstracts for clinical evidence and excluded cadaveric, biomechanical, technique, and review studies. The included abstracts were then independently graded for methodological quality using LOE from Level I (highest quality) to IV (lowest quality) based on the classification system created by The American Academy of Orthopaedic Surgeons (AAOS). Results: Overall, 421 presentations were included and graded for LOE. In general, 17% of the presentations were graded level I; 15% level II; 25% level III; and 43% assigned a LOE of IV. Chi-square analysis demonstrated a statistically significant improvement in the LOE of presentations at the open and closed ASES meetings combined (p = 0.028) between the years 2005 and 2014. In particular, the proportion of presentations graded as level IV significantly decreased over this period (p = \u3c0.001). Conclusions: While most presentations at the ASES annual scientific meetings were of lower LOEs the percentage of level I evidence is greater than that reported at other Orthopaedic meetings. There has been a significant improvement in the LOE of clinical research at open and closed ASES meetings from 2005 to 2014. Specifically, the proportion of level IV studies have dramatically decreased over time
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