188 research outputs found

    Building consensus: idea brokerage in teacher policy networks

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    This is the author accepted manuscript.We show how policy makers converged to support similar reforms on a major educational issue: teacher effectiveness. Our study demonstrates the importance of idea brokers—actors that facilitate connections between preferences in policy networks and promote consensus around new policy ideas. Our study is based on analysis of testimony from 200 Congressional hearingsfrom 2001 to 2015. We use discourse network analysis to examine network ties based on policy preferences expressed in hearings. We visualize policy networks, identify brokers, and estimate exponential random graph models to examine policy changes between the Bush and Obama administrations. We show how idea brokerage is associated with a convergence of policy preferences around teacher effectiveness among a coalition of political actors.William T. Grant Foundatio

    Potential carcinogenic hazards of non-regulated disinfection by-products: Haloquinones, halo-cyclopentene and cyclohexene derivatives, N-halamines, halonitriles, and heterocyclic amines

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    Drinking water disinfectants react with natural organic material (NOM) present in source waters usedfor drinking water to produce a wide variety of by-products. Several hundred disinfections by-products(DBPs) have been identified, but none have been identified with sufficient carcinogenic potency to account for the cancer risks projected from epidemiological studies. In a search for DBPs that might fill this risk gap, the present study projected reactions of chlorine and chloramine that could occur with substructures present in NOM to produce novel by-products. A review of toxicological data on related compounds, supplemented by use of a quantitative structure toxicity relationship (QSTR) program TOPKAT identified chemicals with a high probability of being chronically toxic and/or carcinogenic among 489 established and novel DBPs. Classes of DBPs that were specifically examined were haloquinones (HQs), related halocyclopentene and cyclohexene (HCP&H) derivatives, halonitriles (HNs), organic N-chloramines (NCls), haloacetamides (HAMs), and nitrosamines (NAs). A review of toxicological data available for quinones suggested that HQs and HCP&H derivatives appeared likely to be of health concern and were predicted to have chronic lowest observed adverse effect levels (LOAELs) in the low g/kg day range. Several HQs were predicted to be carcinogenic. Some have now been identified in drinking water. The broader class of HNs was explored by considering current toxicological data on haloacetonitriles and extending this to halopropionitriles. 2,2-dichloropropionitrile has been identified in drinking water at low concentrations, as well as the more widely recognized haloacetonitriles. The occurrence of HAMs has been previously documented. The very limited toxicological data on HAMs suggests that this class would have toxicological potencies similar to the dihaloacetic acids. Organic N-halamines are also known to be produced in drinking water treatment and have biological properties of concern, but no member has ever been characterized toxicologically beyond bacterial or in vitro studies of genotoxicity. The documented formation of several nitrosamines from secondary amines from both natural and industrial sources prompted exploration of the formation of additional nitrosamines. N-diphenylnitrosamine was identified in drinking waters. Of more interest, however, was the formation of phenazine (and subsequently N-chorophenazine) in a competing reaction. These are the first heterocyclic amines that have been identified as chlorination by-products. Consideration of the amounts detected of members of these by-product classes and their probable toxicological potency suggest a prioritization for obtaining more detailed toxicological data of HQs > HCP&H derivatives > NCls > HNs. Based upon a ubiquitous occurrence and virtual lack of in vivo toxicological data, NCls are the most difficult group to assign a priority as potential carcinogenic risks. This analysis indicates that research on the general problem of DBPs requires a more systematic approach than has been pursued in the past. Utilization of predictive chemical tools to guide further research can help bring resolution to the DBP issue by identifying likely DBPs with high toxicological potency

    Optimizing an estuarine water quality monitoring program through an entropy-based hierarchical spatiotemporal Bayesian framework

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    The total maximum daily load program aims to monitor more than 40,000 standard violations in around 20,000 impaired water bodies across the United States. Given resource limitations, future monitoring efforts have to be hedged against the uncertainties in the monitored system, while taking into account existing knowledge. In that respect, we have developed a hierarchical spatiotemporal Bayesian model that can be used to optimize an existing monitoring network by retaining stations that provide the maximum amount of information, while identifying locations that would benefit from the addition of new stations. The model assumes the water quality parameters are adequately described by a joint matrix normal distribution. The adopted approach allows for a reduction in redundancies, while emphasizing information richness rather than data richness. The developed approach incorporates the concept of entropy to account for the associated uncertainties. Three different entropy-based criteria are adopted: total system entropy, chlorophyll-a standard violation entropy, and dissolved oxygen standard violation entropy. A multiple attribute decision making framework is adopted to integrate the competing design criteria and to generate a single optimal design. The approach is implemented on the water quality monitoring system of the Neuse River Estuary in North Carolina, USA. The model results indicate that the high priority monitoring areas identified by the total system entropy and the dissolved oxygen violation entropy criteria are largely coincident. The monitoring design based on the chlorophyll-a standard violation entropy proved to be less informative, given the low probabilities of violating the water quality standard in the estuary. Key Points Developed an entropy-based spatiotemporal framework for network redesign Multiple attribute decision making allows for multi-criteria optimization Showed differences between probability and entropy based redesign approache

    Teachers’ and school leaders’ perceptions of commercialisation in Australian public schools

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    © 2017, The Australian Association for Research in Education, Inc. This paper explores teachers’ and school leaders’ perceptions of commercialisation in Australian public schools, reporting on findings from an open-ended survey question from an exploratory study that sought to investigate teacher and school leader perceptions and experiences of commercialisation. Commercialisation, for the purposes of this paper, is understood as the creation, marketing and sale of education goods and services to schools by for-profit providers and often includes (but is not limited to) the provision of curriculum content, assessment services, data infrastructures, digital learning, remedial instruction, professional development and school administration support. Our account highlights that commercialisation is prevalent in the day-to-day practice of Australian public schools. The perceptions of teachers and leaders suggest that commercialisation is complex, with both affordances and challenges. Respondents acknowledged that aspects of commercialisation are necessary for successfully running schools and classrooms in the 21st century, but also noted that there is a fine line beyond which these seemingly innocuous services become perilous. Concerns focused on how particular services are leading to the deprofessionalisation of teachers as they have less autonomy over what to teach and how to teach it. Moreover, teachers and school leaders reported being perturbed by the idea that commercial providers and services might work to replace teachers in the future. Drawing on these data we argue that growing commercialisation in Australian public schools clearly requires an ethical debate that schools, education professionals, policy makers and interested publics are yet to have

    Silicon startup schools:technocracy, algorithmic imaginaries and venture philanthropy in corporate education reform

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    Technology companies are investing billions of dollars in educational technology, but also creating their own alternative schools. This article traces the emergence of four prototypical ‘silicon startup schools’ as exemplars of a technocratic mode of corporatized education reform: IBM’s P-TECH, part of its Smarter Cities program; AltSchool, a chain of schools based on ‘makerspaces’ established by a former Google executive; Kahn Lab School, a new ‘experimental’ school launched by the founder of the online Kahn Academy; and XQ Super School Project, a ‘crowdsourcing’ project to redesign American high schools funded philanthropically by the wife of Steve Jobs of Apple. Startup schools are analysed as prototype educational institutions that originate in the culture, discourse and ideals of Silicon Valley venture capital and startup culture, and that are intended to relocate its practices to the whole social, technical, political and economic infrastructure of schooling. These new schools are being designed as scalable technical platforms; funded by commercial ‘venture philanthropy’ sources; and staffed and managed by executives and engineers from some of Silicon Valley’s most successful startups and web companies. Together, they constitute a powerful shared ‘algorithmic imaginary’ that seeks to ‘disrupt’ public schooling through the technocratic expertise of Silicon Valley venture philanthropists
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