5,399 research outputs found
Migrant Farmworkers\u27 Perceptions of Pesticide Risk Exposure in Adams County, Pennsylvania: A Cultural Risk Assessment
Agricultural exceptionalism, a system in which regular labor laws and standards do not apply to farm labor, makes migrant farmworkers particularly vulnerable populationsâeconomically, socially, and in terms of environmental health. To address inequities inherent in migrant farmworker marginÂalizaÂtion, studies advocate for actively engaging the migrant farmworker population in the conversation surrounding these issues. We conducted 40 semiÂstructured interviews with migrant farmworkers in Adams County, Pennsylvania, to understand pestiÂcide risk exposure perceptions and practices. We employed the Health Belief Model as our cultural risk assessment frame, using it in combination with technical risk assessment, which uses government calculations (from the Environmental Protection Agency) to quantify pesticide risk exposure. We used mixed methods analyses (quantitative and qualitative) to compare and understand farmworker demographics, perceived risk, perceived control, and risk behavior. Results show that demoÂgraphics âe.g., age, education, visa statusâare important factors in risk perception. They also confirm observations present in many earlier studies. While trainings and educational materials are valuable to help build awareness of risk, a systemic lack of control over their circumstances make it hard for migrant farmworkers to engage in safe behavior. Results also highlight the limitations of technical risk assessment. Such calculations, however, rarely account for risk perceptions and experiences of farmÂworkers themselves. Acknowledging the voices of migrant farmworkers is an essential first step in rebalancing inequities of power in our food systems, and cultural risk assessment can help frame recommendations that target different stakeÂholders across the pesticide regulatory spectrum to ensure migrant farmworker needs and safety
Use of record-linkage to handle non-response and improve alcohol consumption estimates in health survey data: a study protocol
<p>Introduction: Reliable estimates of health-related behaviours, such as levels of alcohol consumption in the population, are required to formulate and evaluate policies. National surveys provide such data; validity depends on generalisability, but this is threatened by declining response levels. Attempts to address bias arising from non-response are typically limited to survey weights based on sociodemographic characteristics, which do not capture differential health and related behaviours within categories. This project aims to explore and address non-response bias in health surveys with a focus on alcohol consumption.</p>
<p>Methods and analysis: The Scottish Health Surveys (SHeS) aim to provide estimates representative of the Scottish population living in private households. Survey data of consenting participants (92% of the achieved sample) have been record-linked to routine hospital admission (Scottish Morbidity Records (SMR)) and mortality (from National Records of Scotland (NRS)) data for surveys conducted in 1995, 1998, 2003, 2008, 2009 and 2010 (total adult sample size around 40â
000), with maximum follow-up of 16â
years. Also available are census information and SMR/NRS data for the general population. Comparisons of alcohol-related mortality and hospital admission rates in the linked SHeS-SMR/NRS with those in the general population will be made. Survey data will be augmented by quantification of differences to refine alcohol consumption estimates through the application of multiple imputation or inverse probability weighting. The resulting corrected estimates of population alcohol consumption will enable superior policy evaluation. An advanced weighting procedure will be developed for wider use.</p>
<p>Ethics and dissemination: Ethics approval for SHeS has been given by the National Health Service (NHS) Multi-Centre Research Ethics Committee and use of linked data has been approved by the Privacy Advisory Committee to the Board of NHS National Services Scotland and Registrar General. Funding has been granted by the MRC. The outputs will include four or five public health and statistical methodological international journal and conference papers.</p>
Sensitivity-analysis method for inverse simulation application
An important criticism of traditional methods of inverse simulation that are based on the NewtonâRaphson algorithm is that they suffer from numerical problems. In this paper these problems are discussed and a new method based on sensitivity-analysis theory is developed and evaluated. The Jacobian matrix may be calculated by solving a sensitivity equation and this has advantages over the approximation methods that are usually applied when the derivatives of output variables with respect to inputs cannot be found analytically. The methodology also overcomes problems of input-output redundancy that arise in the traditional approaches to inverse simulation. The sensitivity- analysis approach makes full use of information within the time interval over which key quantities are compared, such as the difference between calculated values and the given ideal maneuver after each integration step. Applications to nonlinear HS125 aircraft and Lynx helicopter models show that, for this sensitivity-analysis method, more stable and accurate results are obtained than from use of the traditional NewtonâRaphson approach
The Impact of Border Carbon Adjustments under Alternative Producer Responses
Abstract and PDF report are also available on the MIT Joint Program on the Science and Policy of Global Change website (http://globalchange.mit.edu/)Border carbon adjustments (BCAs) have been proposed to address leakage and competitiveness concerns. In traditional assessments, firms regard BCAs as output taxes rather than implicit emissions taxes. Using a stylized energy-economic model, we analyze the impact of BCAs for alternative producer responses. When firms view BCAs as an implicit emissions tax, the outcome depends on whether or not firms can differentiate production across destination markets. If firms are able to produce a low-emissions variety for regions imposing BCAs, results are similar to when firms regard BCAs as an output tax. If firms produce a single variety for all markets, BCAs result in larger leakage reductions than in standard approaches. We also find that BCAs are less effective at addressing competitive concerns in scenarios that result in larger leakage reductions.This study received support from the MIT Joint Program on the Science and Policy of Global Change, which is funded by a consortium of government, industry and foundation sponsors
Observing the spin of a free electron
Long ago, Bohr, Pauli, and Mott argued that it is not, in principle, possible to measure the spin components of a free electron. One can try to use a Stern-Gerlach type of device, but the finite size of the beam results in an uncertainty of the splitting force that is comparable with the gradient force. The result is that no definite spin measurement can be made. Recently there has been a revival of interest in this problem, and we will present our own analysis and quantum-mechanical wave-packet calculations which suggest that a spin measurement is possible for a careful choice of initial conditions
Entrepreneurship Everywhere: Across Campus, Across Communities, and Across Borders
This paper introduces the theme of this special issue related to âEntrepreneurship Everywhere: Across Campus, Across Communities, and Across Borders.â We explore three critical points as we set up the accepted articles for the special issue. First, if we are everywhere are we anywhere? Second, we focus on the importance of collaboration. Third, we discuss the importance of strategically planning on how your efforts intervene or integrate into the wider ecosystem.
Entrepreneurship is everywhere. A search of the term âentrepreneurshipâ on Google yields 132 million results. By comparison a search on âstrategic managementâ yields a mere 17.2 million results. Despite the highly unscientific nature of this comparison, the results shine the light on the tremendous interest and growth in entrepreneurship and entrepreneurs. The job creation potential of small businesses and entrepreneurial firms has captured the attention of politicians from across the globe and the ideological spectrum, who frequently hale the benefits of entrepreneurial activity. Citing work by Tornatzky and Rideout (2014), the Kauffman Foundationâs (2015) âState of Entrepreneurshipâ address indicates that entrepreneurship programs, both curricular and noncurricular, are the fastest-growing programs on college campuses. While many large corporations are villainized, entrepreneurs and small businesses are generally held in high regard and lionized in many instances. Further, interest and growth in the topic of entrepreneurship is unbound by geography or academic discipline. Across many university campuses it is common to find multiple programs and centers dedicated to fostering and growing entrepreneurship. Programs as diverse as engineering, music, pharmacy, agriculture, art, and law are all focusing on helping their students to both engage in entrepreneurial thinking and activity. While the business school remains a key component of the entrepreneurial ecosystem on campuses across the globe, the diversity of programs has grown dramatically. This special issue seeks to highlight this expansive growth by including a diverse set of articles that point to the explosive growth of entrepreneurship and entrepreneurship programing around the world, within our communities and on college campuses. We will briefly preview each of the contributions below, but first we highlight three critical and related questions of the growth of entrepreneurship. First, if entrepreneurship is everywhere, is it truly anywhere? Second, as entrepreneurship continues to be an emphasis across levels of federal, state, and local government and as diverse university entities continue to seek to spark entrepreneurial activities, how is this best managed? Third, how is the entrepreneurial ecosystem affected by the tremendous investment and enhanced focus of universities and government entities in trying to engineer entrepreneurship
No classical limit of quantum decay for broad states
Though the classical treatment of spontaneous decay leads to an exponential
decay law, it is well known that this is an approximation of the quantum
mechanical result which is a non-exponential at very small and large times for
narrow states. The non exponential nature at large times is however hard to
establish from experiments. A method to recover the time evolution of unstable
states from a parametrization of the amplitude fitted to data is presented. We
apply the method to a realistic example of a very broad state, the sigma meson
and reveal that an exponential decay is not a valid approximation at any time
for this state. This example derived from experiment, shows the unique nature
of broad resonances
The role of network density and betweenness centrality in diffusing new venture legitimacy: an epidemiological approach
To survive and grow, new ventures must establish initial legitimacy, and subsequently diffuse this legitimacy through a given population. While the notion of initial legitimacy has received substantial attention in the recent literature, diffusion has not. This work endeavors to outline the legitimacy diffusion process via drawing parallels with the field of epidemiology. Ultimately, to effectively diffuse legitimacy (and grow) a firm must gain positive judgments of appropriateness from members of a given network. Importantly, as with diseases, the characteristics of the network are critical to the diffusion process. A relatively dense network is posited to invoke a normative evaluation process by its members, and can be difficult for new ventures to access, but subsequent diffusion of new venture legitimacy can be rapid. A less dense network, on the other hand, is posited to invoke a pragmatic evaluation process by its members, and is likely easier for new ventures to access initially, but may result in lower levels of new venture legitimacy diffusion in the long run. Theoretical and practical implications are discussed
Subsystems of a finite quantum system and Bell-like inequalities
YesThe set of subsystems Sigma(m) of a finite quantum system Sigma(n) with variables in Z(n) together with logical connectives, is a Heyting algebra. The probabilities tau(m vertical bar rho(n)) Tr vertical bar B(m)rho(n)] (where B(m) is the projector to Sigma(m)) are compatible with associativity of the join in the Heyting algebra, only if the variables belong to the same chain. Consequently, contextuality in the present formalism, has the chains as contexts. Various Bell-like inequalities are discussed. They are violated, and this proves that quantum mechanics is a contextual theory
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