195 research outputs found
Journalism Education: Missing the Democratic Connections
Numerous studies examine public journalism efforts through the practitioner's lens, but scholars, for the most part, have ignored an important aspect of the journalism reform movement -- how journalism educators teach public journalism. David Kurpius, an associate professor of journalism at Louisiana State University, helps bridge this gap in his study of journalism education. In this Kettering Foundation report, Kurpius interviews journalism professors deemed most likely to include public journalism instruction in their syllabi and classroom teaching. He argues that public journalism poses a serious challenge to journalism educators, with many professors missing the democratic connections that are necessary building blocks for students to understand and practice public journalism
Connecting the Dots: A New Method to Determine Radiation Yield during Electron Beam (EB) Polymerization Reactions via Raman Spectroscopy
Electron-beam (EB) polymerization is a fast, solvent-free, low-energy means of polymerizing inks, thin films, and coatings such as those used in food packaging. During EB polymerization, accelerated electrons interact with liquid monomer molecules to form radicals, which continue to react with other monomer molecules and form long chain, solid polymers. The final polymer properties are dependent on the monomer chemistry, as well as processing conditions such as dose (i.e., the amount of energy absorbed by the sample), belt speed (i.e., the rate at which the sample travels through the electron-beam unit), and dose rate (i.e., the rate at which energy is delivered to the system). Unfortunately, the relationships among formulation chemistry, processing conditions, and final polymer properties are not well understood, thereby limiting the growth of EB polymerization in industry. One reason for this is the unpredictable nature of radical formation during EB polymerization. Determination of apparent radiation yield (i.e., number of measurable radicals created per 100 eV of energy absorbed by the system) can facilitate understanding of how radicals are formed during EB reactions, which will allow for better prediction of final polymer properties. Limited research has been conducted to determine the apparent radiation yield of EB-cured polymers, and the work that has been done relies on multiple assumptions. The goal of this research project was to develop a method for determining the apparent radiation yield. Apparent radiation yield is proportional to the apparent rate of initiation (i.e., the change in radical concentration with respect to time). The radical concentration could not be measured directly because the concentration of radicals in the system is so small and because radicals are not easily detected with spectroscopy or other analytical techniques. Instead, a highly reactive inhibitor molecule was added to the formulation, which reacted with the radicals formed by the EB. Each inhibitor molecule reacts with one radical, thus the concentration of radicals is equal to the concentration of inhibitor. Raman Spectroscopy was used to find the delay in conversion caused by the added inhibitor. The inhibitor concentration was plotted versus that conversion delay, and the slope of the resulting best-fit line was the apparent rate of radical formation, which was used to calculate the apparent radiation yield. Using this method, the apparent radiation yield of benzyl acrylate was determined to be 60±40, which is consistent with the theoretical number of radicals that could be produced by 100 eV of energy
Home Modifications for the Elderly
Purpose: The purpose of this project was to identify and present methods to increase a person’s ability to participate in occupations within their home. “Almost 50 million Americans - about one in five - live with a mental or physical disability, many of their homes are inconvenient, restrictive, or dangerous for them,” (McCullagh, 2006, p.54). As a result they are unable to participate in safe and functional occupations.
Methods: A literature review was conducted with the use of Pub Med, AJOT, textbooks, home modification handbooks, and the internet. The literature review determined the need for home modifications with the elderly population and identified current home modification designs and products in order to provide the elderly and their families with current information and recommendations.
Results: A Home Modification Handbook was designed according to the Ecological Model of Occupation. This product has a strong focus on occupations that elderly commonly participate in their home environment. The handbook is for elderly persons who would like to remain in their homes regardless of natural ageing and personal deficits. The handbook includes questions to consider, modifications, and assistive technology products for individual areas of a house including: entrances, interior walkways and doors, kitchen, bathroom, bedroom, living room, laundry, and general safety.
Conclusion: This user friendly handbook will provide elderly individuals and their families the knowledge that will allow them to live safe and independent lives within their own homes
Variations in the Implementation of Ethical Guidelines among Mental Health Professionals in the United States and Denmark
This study focused on the differences and similarities in how mental health professionals in the United States and Denmark implement their ethical guidelines set forth by the American Counseling Association and the Danish Psychological Association (Dansk Psykolog Forening), their specific work settings’ rules and regulations, and their personal values and beliefs when working with clients. Survey packets were developed in English and Danish and administered to 30 United States citizens and 27 Danish mental health professionals. Results indicated that U.S. mental health professionals adhere to their professional ethical guidelines more often than Danish mental health professionals. Results also revealed a positive relationship among professional ethical guidelines, work setting rules and regulations, and personal values and beliefs. Implications for future international, cross-cultural research are considered
An Improved Analysis of Forest Carbon Dynamics using Data Assimilation
There are two broad approaches to quantifying landscape C dynamics - by measuring changes in C stocks over time, or by measuring fluxes of C directly. However, these data may be patchy, and have gaps or biases. An alternative approach to generating C budgets has been to use process-based models, constructed to simulate the key processes involved in C exchange. However, the process of model building is arguably subjective, and parameters may be poorly defined. This paper demonstrates why data assimilation (DA) techniques - which combine stock and flux observations with a dynamic model - improve estimates of, and provide insights into, ecosystem carbon (C) exchanges. We use an ensemble Kalman filter (EnKF) to link a series of measurements with a simple box model of C transformations. Measurements were collected at a young ponderosa pine stand in central Oregon over a 3-year period, and include eddy flux and soil C02 efflux data, litterfall collections, stem surveys, root and soil cores, and leaf area index data. The simple C model is a mass balance model with nine unknown parameters, tracking changes in C storage among five pools; foliar, wood and fine root pools in vegetation, and also fresh litter and soil organic matter (SOM) plus coarse woody debris pools. We nested the EnKF within an optimization routine to generate estimates from the data of the unknown parameters and the five initial conditions for the pools. The efficacy of the DA process can be judged by comparing the probability distributions of estimates produced with the EnKF analysis vs. those produced with reduced data or model alone. Using the model alone, estimated net ecosystem exchange of C (NEE)= -251 f 197g Cm-2 over the 3 years, compared with an estimate of -419 f 29gCm-2 when all observations were assimilated into the model. The uncertainty on daily measurements of NEE via eddy fluxes was estimated at 0.5gCm-2 day-1, but the uncertainty on assimilated estimates averaged 0.47 g Cm-2 day-1, and only exceeded 0.5gC m-2 day-1 on days where neither eddy flux nor soil efflux data were available. In generating C budgets, the assimilation process reduced the uncertainties associated with using data or model alone and the forecasts of NEE were statistically unbiased estimates. The results of the analysis emphasize the importance of time series as constraints. Occasional, rare measurements of stocks have limited use in constraining the estimates of other components of the C cycle. Long time series are particularly crucial for improving the analysis of pools with long time constants, such as SOM, woody biomass, and woody debris. Long-running forest stem surveys, and tree ring data, offer a rich resource that could be assimilated to provide an important constraint on C cycling of slow pools. For extending estimates of NEE across regions, DA can play a further important role, by assimilating remote-sensing data into the analysis of C cycles. We show, via sensitivity analysis, how assimilating an estimate of photosynthesis - which might be provided indirectly by remotely sensed data - improves the analysis of NEE
Climatic versus biotic constraints on carbon and water fluxes in seasonally drought-affected ponderosa pine ecosystems
We investigated the relative importance of climatic versus biotic controls on gross primary production (GPP) and water vapor fluxes in seasonally drought-affected ponderosa pine forests. The study was conducted in young (YS), mature (MS), and old stands (OS) over 4 years at the AmeriFlux Metolius sites. Model simulations showed that interannual variation of GPP did not follow the same trends as precipitation, and effects of climatic variation were smallest at the OS (50%), and intermediate at the YS (<20%). In the young, developing stand, interannual variation in leaf area has larger effects on fluxes than climate, although leaf area is a function of climate in that climate can interact with age-related shifts in carbon allocation and affect whole-tree hydraulic conductance. Older forests, with well-established root systems, appear to be better buffered from effects of seasonal drought and interannual climatic variation. Interannual variation of net ecosystem exchange (NEE) was also lowest at the OS, where NEE is controlled more by interannual variation of ecosystem respiration, 70% of which is from soil, than by the variation of GPP, whereas variation in GPP is the primary reason for interannual changes in NEE at the YS and MS. Across spatially heterogeneous landscapes with high frequency of younger stands resulting from natural and anthropogenic disturbances, interannual climatic variation and change in leaf area are likely to result in large interannual variation in GPP and NEE
Analysis of Signaling Mechanisms Regulating Microglial Process Movement
Microglia, the brain’s innate immune cells, are extremely motile cells, continuously
surveying the CNS to serve homeostatic functions and to respond to pathological events. In the
healthy brain, microglia exhibit a small cell body with long, branched and highly motile
processes, which constantly extend and retract, effectively ‘patrolling’ the brain parenchyma.
Over the last decade, methodological advances in microscopy and the availability of
genetically encoded reporter mice have allowed us to probe microglial physiology in situ.
Beyond their classical immunological roles, unexpected functions of microglia have been
revealed, both in the developing and the adult brain: microglia regulate the generation of
newborn neurons, control the formation and elimination of synapses, and modulate neuronal
activity. Many of these newly ascribed functions depend directly on microglial process
movement. Thus, elucidating the mechanisms underlying microglial motility is of great
importance to understand their role in brain physiology and pathophysiology. Two-photon
imaging of fluorescently labelled microglia, either in vivo or ex vivo in acute brain slices, has
emerged as an indispensable tool for investigating microglial movements and their functional
consequences. This chapter aims to provide a detailed description of the experimental data
acquisition and analysis needed to address these questions, with a special focus on key dynamic
and morphological metrics such as surveillance, directed motility and ramification
Involvement of P2X and P2Y receptors in microglial activation in vivo
Microglial cells are the primary immune effector cells in the brain. Extracellular ATP, e.g., released after brain injury, may initiate microglial activation via stimulation of purinergic receptors. In the rat nucleus accumbens (NAc), the involvement of P2X and P2Y receptors in the generation of microglial reaction in vivo was investigated. A stab wound in the NAc increased immunoreactivity (IR) for P2X1,2,4,7 and P2Y1,2,4,6,12 receptors on microglial cells when visualized with confocal laser scanning microscopy. A prominent immunolabeling of P2X7 receptors with antibodies directed against the ecto- or endodomain was found on Griffonia simplicifolia isolectin-B4-positive cells. Additionally, the P2X7 receptor was colocalized with active caspase 3 but not with the anti-apoptotic marker pAkt. Four days after local application of the agonists α,βmeATP, ADPβS, 2MeSATP, and BzATP, an increase in OX 42- and G. simplicifolia isolectin-IR was observed around the stab wound, quantified both densitometrically and by counting the number of ramified and activated microglial cells, whereas UTPγS appeared to be ineffective. The P2 receptor antagonists PPADS and BBG decreased the injury-induced increase of these IRs when given alone and in addition inhibited the agonist effects. Further, the intra-accumbally applied P2X7 receptor agonist BzATP induced an increase in the number of caspase-3-positive cells. These results indicate that ATP, acting via different P2X and P2Y receptors, is a signaling molecule in microglial cell activation after injury in vivo. The up-regulation of P2X7-IR after injury suggests that this receptor is involved in apoptotic rather than proliferative effects
Evolving Responsibility or Revolving Bias? The Role of the Media in the anti-sugar debate in the UK Press.
Social responsibility of the media theory has been around for decades, and this theory is closely related to a report published by the Hutchins Commission in 1947, A Free and Responsible Press. Using social responsibility theory as a theoretical framework and recommendations from A Free and Responsible Press report, we analysed the coverage about the anti-sugar debate and the supermarket industry in the British press in a period between 2010 and 2015. Using content analysis as a method, we analysed press releases and surveys published by Action on Sugar as a main anti-sugar advocate in the UK and then we traced these public relations (PR) materials in the press coverage. We also analysed media bias focusing on the nature of quoting sources and whether media give a voice to everyone, both the anti-sugar activists and the relevant industry figures who claim that sugar is not the only reason for the current obesity problem. Results show that the media do not give a voice to the industry but only to the anti-sugar NGO. Nevertheless, the media remove sources from the industry from their coverage even when Action on Sugar mentions the industry in their documents
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