33659 research outputs found
Sort by
A Hedonic Study of New England Dam Removals
Get PDFThere are over fourteen thousand dams in the New England region. Recent efforts to remove dams to return rivers back to their natural orientations in the United States have increased, though a host of potential externalities exist to nearby communities. We compile 75 removed dams in the New England region to estimate the aggregate treatment effect of dam removal on nearby properties. We employ a repeat sales sample with property fixed effects and a difference-in-differences strategy to estimate the proximity effects of dam removal. We cannot reject the null hypothesis that dam removals have no effect on proximity properties
Establishing Meaning and Values in Marketing and Broadening Perspectives in Understanding Nationhood and Climate Change
Get PDFPre-service training on media education for teachers at Czech universities
Get PDFThe study shows the content of future teachers’ education and their needs to teach media education in their future practice. The preparation of future teachers within the faculties of education varies considerably across Europe, as does the level of teaching in primary and secondary schools. In the Czech Republic, media education is a cross-cutting topic in primary and some types of secondary schools and is rather rarely found in the university training of future teachers. The research shows the areas in which future teachers were prepared in their teacher training, their sense of readiness to teach and their needs in their training
Media literacy policy in Morocco: A strategic milestone missing
Get PDFIn the digital age, diverse walks of human life have reconfigured profoundly. In the Moroccan society, digitalisation plans and the skyrocketing numbers of internet users necessitate coping literacy policies. While several community initiatives have been taken to improve the quality of media literacy, they, as bottom-up efforts, cannot suffice to meet the needs of the whole Moroccan population. Rather, the absence of a central, nationwide, cross-sectoral media literacy policy significantly challenges the effective coordination of official strategies and community initiatives in media education. This article investigates current practices in media literacy in Morocco. Using document analysis, it delves into data gathered from various official sources, media announcements, and activities on media literacy. The analysis of Moroccan policies in the disciplines of education and media regulation reveals the critical need for a national, cross-sectoral media literacy policy to coordinate the regulatory promises and practical efforts that look discrepant, shambolic and limited in impact
Combined Effects of Fronts, Upwelling and the Biological Pump on Organophosphate Esters in the Changjiang (Yangtze) River Estuary During Summer
Get PDFEstuarine and coastal environments are important transport pathways and regional sinks for anthropogenic pollutants. In this study, the occurrence and transport of the continuously released organophosphate esters (OPEs) was investigated together with physical and biochemical parameters throughout the water column in the Changjiang (Yangtze) River estuary during the summer. Total dissolved and particulate OPEs showed great spatial heterogeneity, with mean concentrations of 550 ± 280 ng/L in the estuary, 110 ± 270 ng/L in the front/upwelling zone, and 410 ± 450 ng/L in the continental shelf. OPE concentrations in the estuarine bottom waters were high due to massive terrestrial/sediment inputs. In contrast, the “surface enrichment and depth depletion” of OPEs in the continental shelf was closely related to seasonal stratification. Reduced OPE concentrations were observed in the frontal/upwelling zone due to isopycnal heaving. Frontal activity and upwelling induced phytoplankton blooms in the coastal regions, which jointly contributed to elevated OPEs beneath surface water with high phytoplankton aggregation. The OPEs mainly originated from wastewater treatment plant discharges, industrial pollution and consumer products. These OPEs generally posed a low ecological risk to aquatic lives, but their long-term effects cannot be ignored due to their continuous high production, usage and release
Insights from Fossil-Bound Nitrogen Isotopes in Diatoms, Foraminifera, and Corals
Get PDFNitrogen is a major limiting element for biological productivity, and thus understanding past variations in nitrogen cycling is central to understanding past and future ocean biogeochemical cycling, global climate cycles, and biodiversity. Organic nitrogen encapsulated in fossil biominerals is generally protected from alteration, making it an important archive of the marine nitrogen cycle on seasonal to million-year timescales. The isotopic composition of fossil-bound nitrogen reflects variations in the large-scale nitrogen inventory, local sources and processing, and ecological and physiological traits of organisms. The ability to measure trace amounts of fossil-bound nitrogen has expanded with recent method developments. In this article, we review the foundations and ground truthing for three important fossil-bound proxy types: diatoms, foraminifera, and corals. We highlight their utility with examples of high-resolution evidence for anthropogenic inputs of nitrogen to the oceans, glacial-interglacial-scale assessments of nitrogen inventory change, and evidence for enhanced CO2 drawdown in the high-latitude ocean. Future directions include expanded method development, characterization of ecological and physiological variation, and exploration of extended timescales to push reconstructions further back in Earth\u27s history
Evaluation of new and net community production estimates by multiple ship-based and autonomous observations in the Northeast Pacific Ocean
Get PDFNew production (NP) and net community production (NCP) measurements are often used as estimates of carbon export potential from the mixed layer of the ocean, an important process in the regulation of global climate. Diverse methods can be used to measure NP and NCP, from research vessels, autonomous platforms, and remote sensing, each with its own set of benefits and uncertainties. The various methods are rarely applied simultaneously in a single location, limiting our ability for direct comparisons of the resulting measurements. In this study, we evaluated NP and NCP from thirteen independent datasets collected via in situ, in vitro, and satellite-based methods near Ocean Station Papa during the 2018 Northeast Pacific field campaign of the NASA project EXport Processes in the Ocean from RemoTe Sensing (EXPORTS). Altogether, the datasets indicate that carbon export potential was relatively low (median daily averages between -5.1 and 12.6 mmol C m-2 d-1), with most measurements indicating slight net autotrophy in the region. This result is consistent with NCP estimates based on satellite measurements of sea surface temperature and chlorophyll a. We explored possible causes of discrepancies among methods, including differences in assumptions about stoichiometry, vertical integration, total volume sampled, and the spatiotemporal extent considered. Results of a generalized additive mixed model indicate that the spatial variation across platforms can explain much of the difference among methods. Once spatial variation and temporal autocorrelation are considered, a variety of methods can provide consistent estimates of NP and NCP, leveraging the strengths of each approach
Two-stage multivariate dynamic linear models to extract environmental and climate signals in coastal ecosystem data
No full textIn environmental time series the presence of missing data, desire for multiple modeling structures, non-simultaneous data streams and computationally costly inference in highly parameterized model structures bring major challenges. In this work, we describe how multistage dynamic linear model (DLM) structures can be used to concomitantly describe long-term patterns, infer missing data, test predictive relationships, and altogether facilitate model development where multiple objectives and data streams may exist. We demonstrate the utility of this modeling approach with longterm data from Narragansett Bay (NB), Rhode Island, USA which has undergone major ecological changes including reductions in anthropogenic nutrient pollution. In a first stage, DLMs were used both to interpolate missing data and describe changes in both seasonality and long-term trend for nitrogenous nutrients and size structure of phytoplankton communities. These models revealed a long-term decline in large phytoplankton, and intensifying seasonal blooms for smaller phytoplankton. In a second modeling stage, parameters with associated uncertainty from stage 1 were used as covariates to test how features of the nitrogen series impacted phytoplankton. Conditional on the posterior inference of predictors modeled in stage 1, the dynamic regression revealed a newly discovered seasonal dependence of large phytoplankton on nitrogen sources