2,140 research outputs found
4th survey of parents of three and four year old children and their use of early years services (Summer 1999 to Spring 2000)
The effects of opioids on the peripheral terminals of rat and guinea pig sensory neurons
Studies in vivo and in vitro suggest that opioids can modulate nociceptive signals by interacting with receptors on peripheral neurons. We investigated the peripheral actions of mu (μ), delta (δ), and kappa (κ) opioid agonists using an electrophysiological model of inflammatory-type nociception. Dorsal horn convergent neurons were recorded extracellularly in the halothane anesthetized intact adult rat. Subcutaneous injection of formalin into the hindpaw receptive field of these neurons results in two distinct phases of cell firing. Neither morphine, exogenous ligand for the μ receptor, nor the δ agonist Tyr-D-Ser-(tbu)-Gly-Phe-Leu-Thr (DSTBULET) influenced the formalin response when administered peripherally into the paw. The κ-selective ligand U50488H produced a dose-dependent, naloxone-reversible inhibition of both phases of formalin-induced activity which does not result from leakage of the drug into the systemic circulation. Intrathecal administration of μ and δ, but not κ, opioids has previously been shown to inhibit the biphasic formalin response in the adult rat. Our data suggest that different types of opioid receptors may be important in the periphery and spinal cord.
There is some indication that opioid receptor populations are different in adult and neonatal rat spinal cord. For example there are functional μ and κ, but not δ, opioid receptors in an in vitro model of nociceptive activity in the neonatal rat spinal cord. We looked at these apparent developmental differences in binding assays in which opioid receptors in the two tissues were characterized by measurements of ligand binding to crude membrane fractions. Results from binding studies agreed well with fictional studies, in that δ opioid binding sites were not detected on neonatal rat spinal cord membranes. Levels of κ binding were higher in the neonate than in the adult.
Novel continuous clonal cell lines with some characteristics of nociceptive dorsal root ganglion (DRG) neurons were tested as a potential model system for the action of opioids on primary afferent nerve fibers. Two of the cell lines expressed δ, but not μ or κ, opioid binding sites. We could not detect effects of δ opioids on potassium currents (as measured by 86Rubidium efflux) or on the release of substance P-like immunoreactivity (SP-LI). We concluded that these cell lines were not good models for studying opioid action on sensory neurons.
Measurement of SP-LI release from guinea pig cardiac right ventricular slices did provide a useful model to study peripheral actions of opioids. Formalin (0.2%), capsaicin (100 nM-3μM), and a depolarizing concentration of potassium (100 mM K+) increased the outflow of SP-LI from heart slices. Agonists at μ, δ, and κ opioid receptors inhibited K+-stimulated release and these effects were reversed by naloxone to differing degrees. High concentrations of μ and κ ligands, in their own right, increased the outflow of SP-LI, and these results are compared to previous reports of opioid excitation. Formalin-evoked SP-LI release from heart slices was subject to modulation by opioids. These results agreed well with in vivo results, in that SP-LI release evoked by formalin was not inhibited by μ or δ opioid agonists, but was sensitive to blockade by the κ ligand U50488H.
We have demonstrated effects of opioids on the peripheral terminals of sensory neurons in two different models. Peripheral κ, but not μ or δ, receptors were important in modulating formalin-induced effects both in vivo and in vitro. Central κ receptors, at least in adult rats, have been shown not to influence the formalin response in vivo to the same extent as μ and δ receptors. In vitro μ, δ, and κ opioids modulated responses to K+ depolarization of sensory neurons at the peripheral terminals. These results provide strong evidence that peripheral opioid receptors can modulate nociceptive signals
An Action Study of the Design, Delivery and Evaluation of an Undergraduate Course in Creative Problem Solving
The purpose of this project was to prepare and carry out a formal action study documenting the design, delivery and evaluation of an undergraduate course that emphasized the development of students’ understanding of creative thinking and the Creative Problem Solving process. This research project focused on a specific course that was available to junior and senior students at Texas A&M University in College Station, Texas. The title of the course was “Applications of Creativity and Creative Problem Solving” and the course was offered by the Department of Educational Psychology. This project contains an investigation of selected literature sources that could serve as key texts for such a course in creativity and Creative Problem Solving. Detailed annotations were developed based on a set of specific criteria. The annotations summarize the key elements covered in the text, as well a point out potential challenges that might arise from the use of the text as a textbook for a creativity course. The two qualitative analysis methods that were used in order to reach the recommendations and conclusions for this study were Within-Site Analysis and Cross-Site Analysis (Miles & Huberman, 1994). The author of this work, who served as instructor for the course, took detailed journal entries; detailing the design, delivery and evaluation of each class. Three major pieces of data were collected and analyzed as part of the final Cross-Site Analysis: lesson plans from each class, the journal that was kept about the design, delivery and evaluation of each class and the Within-Site Analysis that was performed for each class day. Lastly, overall learning points were developed from the Cross-Site Analysis performed across all the Within-Site Summaries. For the Cross-Site Analysis the writer looked at all three sections (Design, Delivery and Evaluation) of each Within-Site Summary; noting common threads that happened across all the class days. From this analysis, overall insights were developed into Key Learning Points that have the potential of impacting the future design and delivery of related courses on creativity and Creative Problem Solving
An Assessment Of Long-Term Changes In The Characterisitcs Of Precipitation In The Upper Midwest
As climate change progresses, many forecasts for the upper Midwest predict increases in annual precipitation, but with a shift in seasonal patterns that will leave the summer months drier with less frequent, higher magnitude storm events. Changes in precipitation patterns have the potential to alter the sediment budget and discharge patterns in watersheds. The purpose of this study was to determine the effects changes in frequency, magnitude, duration, and intensity of precipitation might have on streamflow and sediment budgets in the upper Midwest. This analysis was carried out using hourly precipitation data from 1948 to 2013 from 23 sites and 8 river basins in Minnesota, Wisconsin, North Dakota, South Dakota, Nebraska, and Iowa. The hourly precipitation data provide a high-resolution archive that is ideal for analyzing changing patterns in rainfall at multiple scales: including decadal, yearly, monthly, and individual storm event. The upper Midwest is experiencing decreasing storm durations, decreasing numbers of storm events, increasing average rainfall intensities, increasing maximum rainfall intensities, increasing amounts of rainfall per storm, and increasing average annual precipitation. These data demonstrate that significant changes in precipitation and streamflow patterns have occurred over the past 60 years. The observed changes are consistent with the predictions derived from various climate models and, as such, may lend support to forecasts of additional shifts in precipitation patterns in the coming decades. Understanding and quantifying these changes, particularly the trend of shorter more intense storms, has large implications on the sediment budget and discharge patterns of upper Midwest watersheds
Examining Impacts on Water Demand Resulting from Population and Employment Growth Using a Regional Adjustment Model
This thesis examines the currently available water use data and its limitation for use in scientific research. The first chapter offers a description of the current nationwide water data including descriptions of collection methods and trends found within the data. The varying collection methods used result in inconsistencies within the datasets and between the years. These inconsistencies have resulted in the data being used more as a point of reference than in nationwide empirical analysis of water use. There has been a calling for systematic improvements to the data, which could contribute to greater empirical analysis taking place at the national level. Chapter 2 acts as a caveat to Chapter 3 which employs the nationwide data to examine the impacts of population and employment growth on water demand. The growth dynamic of population and employment has been shown to impact resources utilized by households and firms such as land absorption rates. This thesis applies a regional adjustment model to model the impacts of population and employment growth on water demand. Furthermore, the thesis projects whether water use per person and water use per employee is adjusting towards a future steady state equilibrium. By doing so, this work looks to further the calls for improvements to the Nation’s water use data
How Adult Students Experience Having Their Beliefs Challenged in an Undergraduate Religion Class: A Phenomenological Analysis
The challenging of one’s existing ideas has long been acknowledged as an integral component of the learning experience. In a university classroom, challenges are often inherent to the process. When challenges address personal beliefs, there is potential for the experience to be unsettling. The current study is designed to gain a deeper look into this phenomenon.
The purpose of this study is to examine the experiences of adult students in a college religion class who have encountered questions about and challenges to their previously held beliefs. The study was conducted with adult non-traditional students who have participated in an academically-focused college level religion class at a Baptist affiliated university with a liberal arts emphasis. Using the phenomenological research method developed at the University of Tennessee (Thomas & Pollio, 2002), eight participants were interviewed regarding their experience. All were asked to talk about a time one of their beliefs was challenged in their undergraduate religion course.
Utilizing the concept of figure/ground as an interpretive framework, the data revealed three themes that stood out against the ground of the learners’ expectations of being challenged. First, participants experienced an environment of challenge filled with varied and powerful challenges that often came quickly. While some spoke of theological beliefs that were challenged, others described challenges to beliefs about others and how they would be treated in a religion class, the teachers’ pedagogy, and their own personal epistemology. The influence of professors stood out as a second theme as they set a tone for the class, and served as models for the environment. Professors had both positive and negative effects on the learners. The final theme deals with the choices participants made: the challenges caused some to broaden their mindsets, while others chose to not allow their beliefs to be corroded.
These findings reveal highly individualized learning experiences laden with the potential for powerful challenges to the learner’s beliefs and identity. The level of expectation for challenges to beliefs brought to the learning environment influenced the impact of the challenges. Teachers played a significant role in establishing an environment where effective reflective learning could occur
In Better Fettle: Improvement, Work and Rhetoric in the Transition to Environmental Farming in the North York Moors
Through ethnographic research amongst farmers in the North York Moors, and through broader historical and political analysis, I examine the importance and role of values in hard work and beneficent change in negotiated interactions between policy-makers, farmers and conservationists. Within the context of a shift in agricultural support away from production to environmental protection, and within the context of a local conservation initiative to protect a population of freshwater pearl mussels in the River Esk, I show the importance of these values for the construction of farmers' personhoods and their symbolic relations and means of expression through the landscape. I show how those values are persistent and pervasive, yet at the same time mutable and open to interpretation. In particular, I examine alternative conceptions of beneficent change through recourse to the words fettle and improvement. Fettling places value in long-term, steady and incremental change, whereas improvement places value in changes more closely associated with productivist ideals such as expansion and profit. I suggest that it is the mutability of farming values that gives rise to their persistence as they come to be used and reinterpreted according to the changing contexts of their application and the differing interests of a range of groups and individuals. By showing that farmers are able to uphold and express their values differently I argue that it is not so straightforward to predict farmers' responses to changing political exigencies or local conservation initiatives on the basis of homogenous values or the categorisation of farmers into defined "types". Through a rhetoric-culture approach I argue that changes in farming values through time do not merely reflect changing political interests and farmers' subsequent accommodation of them. Rather, it reflects the continued negotiation of those values between farmers and others in the play of agents and patients in the construction of personhood and the formulation of arguments. I argue that the persistence of fettling interpretations of a value in beneficent change reflects the agentive actions of farmers as it remains a useful argumentative strategy with which they can make indictments against new policy impositions and, moreover, it remains functional in guiding their practices in ways suitable to the environment in which they farm
Fifth survey of parents of three and four year old children and their use of early years services (Summer 2000 to Spring 2001)
The main aim of the survey was to establish rates of participation for three and four year olds in all forms of pre-school provision in England... The survey also investigated the characteristics of providers used and parents’ opinions of the quantity and quality of provision in the local area in general as well as of the providers they used, and the influences on their choice of providers
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