97 research outputs found

    Explaining Heterogeneity in the Organization of Scientific Work

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    Prior studies of academic science have largely focused on researchers in life sciences or engineering. However, while academic researchers often work under similar institutions, norms, and incentives, they vary greatly in how they organize their research efforts across different scientific domains. This heterogeneity, in turn, has important implications for innovation policy, the relationship between industry and academia, the scientific labor market, and the perceived deficit in the relevance of social sciences and humanities research. To understand this heterogeneity, we model scientists as publication-maximizing agents, identifying two distinct organizational patterns that are optimal under different parameters. When the net productivity of research staff (e.g., PhD students and postdocs) is positive, the funded research model with an entrepreneurial scientist and a large team dominates. When the costs of research staff exceed their productivity benefits, the hands-on research approach is optimal. The model implies significant heterogeneity across the two modes of organizing in research funding, supply of scientific workforce, team size, publication output, and stratification patterns over time. Exploratory empirical analysis finds consistent patterns of time allocation and publication in a prior survey of faculty in U.S. universities. Using data from an original survey, we also find causal effects consistent with the modelโ€™s prediction on how negative shocks to research staffโ€”due to visa or health problems, for exampleโ€”differentially impact research output under the two modes of organization

    Best-fitting prediction equations for basal metabolic rate: informing obesity interventions in diverse populations

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    Basal Metabolic Rate (BMR) represents the largest component of total energy expenditure and is a major contributor to energy balance. Therefore, accurately estimating BMR is critical for developing rigorous obesity prevention and control strategies. Over the past several decades, numerous BMR formulas have been developed targeted to different population groups. A comprehensive literature search revealed 248 BMR estimation equations developed using diverse ranges of age, gender, race, fat free mass, fat mass, height, waist-to-hip ratio, body mass index, and weight. A subset of 47 studies included enough detail to allow for development of meta-regression equations. Utilizing these studies, meta-equations were developed targeted to twenty specific population groups. This review provides a comprehensive summary of available BMR equations and an estimate of their accuracy. An accompanying online BMR prediction tool (available at http://www.sdl.ise.vt.edu/tutorials.html) was developed to automatically estimate BMR based on the most appropriate equation after user-entry of individual age, race, gender, and weight

    Social influence in childhood obesity interventions: a systematic review

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    The objective of this study is to understand the pathways through which social influence at the family level moderates the impact of childhood obesity interventions. We conducted a systematic review of obesity interventions in which parents' behaviours are targeted to change children's obesity outcomes, because of the potential social and environmental influence of parents on the nutrition and physical activity behaviours of children. PubMed (1966โ€“2013) and the Web of Science (1900โ€“2013) were searched, and 32 studies satisfied our inclusion criteria. Results for existing mechanisms that moderate parents' influence on children's behaviour are discussed, and a causal pathway diagram is developed to map out social influence mechanisms that affect childhood obesity. We provide health professionals and researchers with recommendations for leveraging family-based social influence mechanisms to increase the efficacy of obesity intervention programmes

    Dynamics of intervention adoption, implementation, and maintenance inside organizations: The case of an obesity prevention initiative

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    Overall impact of public health prevention interventions relies not only on the average efficacy of an intervention, but also on the successful adoption, implementation, and maintenance (AIM) of that intervention. In this study, we aim to understand the dynamics that regulate AIM of organizational level intervention programs. We focus on two well-documented obesity prevention interventions, implemented in food carry-outs and stores in low-income urban areas of Baltimore, Maryland, which aimed to improve dietary behaviour for adults by providing access to healthier foods and point-of-purchase promotions. Building on data from field observations, in-depth interviews, and data discussed in previous publications, as well as the strategy and organizational behaviour literature, we developed a system dynamics model of the key processes of AIM. With simulation analysis, we show several reinforcing mechanisms that span stakeholder motivation, communications, and implementation quality and costs can turn small changes in the process of AIM into big difference in the overall impact of the intervention. Specifically, small changes in the allocation of resources to communication with stakeholders of intervention could have a nonlinear long-term impact if those additional resources can turn stakeholders into allies of the intervention, reducing the erosion rates and enhancing sustainability. We present how the dynamics surrounding communication, motivation, and erosion can create significant heterogeneity in the overall impact of otherwise similar interventions. Therefore, careful monitoring of how those dynamics unfold, and timely adjustments to keep the intervention on track are critical for successful implementation and maintenance

    THE ROLE OF INTERDEPENDENCE IN THE MICRO-FOUNDATIONS OF ORGANIZATION DESIGN: TASK, GOAL, AND KNOWLEDGE INTERDEPENDENCE

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    Interdependence is a core concept in organization design, yet one that has remained consistently understudied. Current notions of interdependence remain rooted in seminal works, produced at a time when managersโ€™ near-perfect understanding of the task at hand drove the organization design process. In this context, task interdependence was rightly assumed to be exogenously determined by characteristics of the work and the technology. We no longer live in that world, yet our view of interdependence has remained exceedingly task-centric and our treatment of interdependence overly deterministic. As organizations face increasingly unpredictable workstreams and workers co-design the organization alongside managers, our field requires a more comprehensive toolbox that incorporates aspects of agent-based interdependence. In this paper, we synthesize research in organization design, organizational behavior, and other related literatures to examine three types of interdependence that characterize organizationsโ€™ workflows: task, goal, and knowledge interdependence. We offer clear definitions for each construct, analyze how each arises endogenously in the design process, explore their interrelations, and pose questions to guide future research

    Modeling the adoption of innovations in the presence of geographic and media influences

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    While there has been much work examining the affects of social network structure on innovation adoption, models to date have lacked important features such as meta-populations reflecting real geography or influence from mass media forces. In this article, we show these are features crucial to producing more accurate predictions of a social contagion and technology adoption at the city level. Using data from the adoption of the popular micro-blogging platform, Twitter, we present a model of adoption on a network that places friendships in real geographic space and exposes individuals to mass media influence. We show that homopholy both amongst individuals with similar propensities to adopt a technology and geographic location are critical to reproduce features of real spatiotemporal adoption. Furthermore, we estimate that mass media was responsible for increasing Twitter's user base two to four fold. To reflect this strength, we extend traditional contagion models to include an endogenous mass media agent that responds to those adopting an innovation as well as influencing agents to adopt themselves

    Towards the development of a simulator for investigating the impact of people management practices on retail performance

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    ๏€Œ๏€‰๏€ž๏€„๏€‚ ๏€ˆ๏€„๏€๏€„๏€ˆ๏€‚ ๏€ ๏€Š๏€‚ ๏€‰๏€๏€Ž๏€ž๏€…๏€‰๏€“๏€ž๏€Œ๏€ ๏€•๏€‚ ๏€Š๏€ ๏€…๏€‚ ๏€‰๏€‚ ๏€Ž๏€ฃ๏€„๏€“๏€Œ๏€Š๏€Œ๏€“๏€‚ ๏€‰๏€ฃ๏€ฃ๏€ˆ๏€Œ๏€“๏€‰๏€ž๏€Œ๏€ ๏€•๏€‚ ๏€Œ๏€Ž๏€‚ ๏€ ๏€Š๏€ž๏€„๏€•๏€‚ ๏€ข๏€ ๏€…๏€„๏€‚ ๏€ ๏€Š๏€‚ ๏€‰๏€•๏€‚ ๏€‰๏€…๏€ž๏€‚ ๏€ž๏€™๏€‰๏€•๏€‚ ๏€‰๏€‚\ud ๏€Ž๏€“๏€Œ๏€„๏€•๏€“๏€„๏€›๏€‚๏€š๏€„๏€‚ ๏€™๏€‰๏€๏€„๏€‚ ๏€ฎ๏€„๏€๏€„๏€ˆ๏€ ๏€ฃ๏€„๏€ฎ๏€‚ ๏€‰๏€‚ ๏€…๏€„๏€ž๏€‰๏€Œ๏€ˆ๏€‚ ๏€๏€…๏€‰๏€•๏€“๏€™๏€‚ ๏€Ž๏€Œ๏€ข๏€ค๏€ˆ๏€‰๏€ž๏€Œ๏€ ๏€•๏€‚๏€ข๏€ ๏€ฎ๏€„๏€ˆ๏€‚ ๏€ž๏€ ๏€‚ ๏€Œ๏€•๏€๏€„๏€Ž๏€ž๏€Œ๏€œ๏€‰๏€ž๏€„๏€‚๏€‘๏€™๏€Œ๏€“๏€™๏€‚ ๏€ˆ๏€„๏€๏€„๏€ˆ๏€‚ ๏€ ๏€Š๏€‚\ud ๏€ข๏€ ๏€ฎ๏€„๏€ˆ๏€‚๏€‰๏€“๏€“๏€ค๏€…๏€‰๏€“๏€Ÿ๏€‚๏€Œ๏€Ž๏€‚๏€…๏€„๏€ณ๏€ค๏€Œ๏€…๏€„๏€ฎ๏€‚๏€Š๏€ ๏€…๏€‚๏€Ž๏€ค๏€“๏€™๏€‚๏€‰๏€‚๏€ข๏€ ๏€ฎ๏€„๏€ˆ๏€‚๏€ž๏€ ๏€‚๏€ ๏€๏€ž๏€‰๏€Œ๏€•๏€‚๏€ข๏€„๏€‰๏€•๏€Œ๏€•๏€œ๏€Š๏€ค๏€ˆ๏€‚๏€…๏€„๏€Ž๏€ค๏€ˆ๏€ž๏€Ž๏€‚๏€Š๏€ ๏€…๏€‚๏€ฃ๏€…๏€‰๏€“๏€ž๏€Œ๏€ž๏€Œ๏€ ๏€•๏€„๏€…๏€Ž๏€›

    A systematic review to identify areas of enhancements of pandemic simulation models for operational use at provincial and local levels

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    <p>Abstract</p> <p>Background</p> <p>In recent years, computer simulation models have supported development of pandemic influenza preparedness policies. However, U.S. policymakers have raised several <it>concerns </it>about the practical use of these models. In this review paper, we examine the extent to which the current literature already addresses these <it>concerns </it>and identify means of enhancing the current models for higher operational use.</p> <p>Methods</p> <p>We surveyed PubMed and other sources for published research literature on simulation models for influenza pandemic preparedness. We identified 23 models published between 1990 and 2010 that consider single-region (e.g., country, province, city) outbreaks and multi-pronged mitigation strategies. We developed a plan for examination of the literature based on the concerns raised by the policymakers.</p> <p>Results</p> <p>While examining the concerns about the adequacy and validity of data, we found that though the epidemiological data supporting the models appears to be adequate, it should be validated through as many updates as possible during an outbreak. Demographical data must improve its interfaces for access, retrieval, and translation into model parameters. Regarding the concern about credibility and validity of modeling assumptions, we found that the models often simplify reality to reduce computational burden. Such simplifications may be permissible if they do not interfere with the performance assessment of the mitigation strategies. We also agreed with the concern that social behavior is inadequately represented in pandemic influenza models. Our review showed that the models consider only a few social-behavioral aspects including contact rates, withdrawal from work or school due to symptoms appearance or to care for sick relatives, and compliance to social distancing, vaccination, and antiviral prophylaxis. The concern about the degree of accessibility of the models is palpable, since we found three models that are currently accessible by the public while other models are seeking public accessibility. Policymakers would prefer models scalable to any population size that can be downloadable and operable in personal computers. But scaling models to larger populations would often require computational needs that cannot be handled with personal computers and laptops. As a limitation, we state that some existing models could not be included in our review due to their limited available documentation discussing the choice of relevant parameter values.</p> <p>Conclusions</p> <p>To adequately address the concerns of the policymakers, we need continuing model enhancements in critical areas including: updating of epidemiological data during a pandemic, smooth handling of large demographical databases, incorporation of a broader spectrum of social-behavioral aspects, updating information for contact patterns, adaptation of recent methodologies for collecting human mobility data, and improvement of computational efficiency and accessibility.</p
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