1,320 research outputs found
Code Switching Ability of Deaf Students and its Relationship to Reading Comprehension Performance
The purpose of this study was to investigate the relationship between deaf students’ ability to code switch for ASL to written English and their reading comprehension performance.
A t-test was used to test the hypotheses presented in this study. The correlations between code switching ability and reading comprehension performance were established.
The findings of this study indicated that a strong correlation exists between deaf students\u27 code switching ability and their reading comprehension performance. The findings of this study also showed a significant difference between the code switching scores of deaf students of deaf parents and deaf students of hearing parents. A significant difference between the reading comprehension performances of deaf students of deaf parents and deaf students of hearing parents was not found
Essays on excise taxation: Cross -border effects, quality substitution, and tax earmarking
This dissertation is a collection of essays examining the secondary effects of excise taxation. The first chapter discusses the history of the excise tax in the United States and provides an introduction to some of the major areas of research examining the excise tax. In addition, this chapter outlines the research agenda for the dissertation. Chapter 2 considers the effects of cross-border sales and tourism on state tax revenues from wine and liquor taxation in the state of West Virginia. The empirical results of this chapter suggest that the revenue impact of cross-border shopping and tourism is economically significant relative to the total tax revenue collected from these sources. Chapter 3 empirically analyzes the effects of the gasoline excise tax on the purchase of gasoline grade. The results show that the per-unit excise tax causes consumers to substitute toward higher quality (higher octane) gasoline while the ad valorem excise tax exerts little influence on the purchase of gasoline grade. Chapter 4 builds upon the previous chapter by modifying the empirical model to control for spatial dependence and controlling for the impact that cross-border shopping may have on the purchase of quality. The results suggest that an increase in a state\u27s per-unit excise tax induces two conflicting effects on the purchase of product quality, with the cross-border effect dominating the relative-price effect. Thus, an increase in a state\u27s per-unit excise tax is found to cause a decline in average product quality in the state. Chapter 5 examines the potential for crowd-out in state highway financing. The results indicate that states respond to federal grants and state earmarked revenues similarly and that these sources of revenue do not cause crowding-out. Finally, Chapter 6 summarizes the major findings of the previous chapters and discusses areas of future research
A Comparison of Clustered and Isolated Casino Performance in Missouri
This paper utilizes data on Missouri’s casino industry to examine how clustered casinos, such as those in Kansas City and St. Louis, perform compared to dispersed or isolated casinos, such as those in Boonville, Caruthersville, La Grange, and St. Joseph. Missouri limits the number of casino licenses allowed; however, it does not explicitly mandate casino locations. Missouri provides a unique natural experiment for comparing location model performance. Although there is no published research on which type of casino location model is more effective for generating industry revenues and associated taxes, state legislatures have nevertheless been following an isolated casino location model. But it is not at all obvious that this strategy leads to higher aggregate revenues. Using 2011 data on Missouri’s casino industry, we find that casino performance may not depend on whether it is isolated or in a cluster. This result suggests that the casino market is relatively efficient, given the regulations it faces. However, there may still be significant costs from restricting casino locations. We speculate that politicians are likely to use the isolated model as a mechanism to maximize voter support for casino legalization
SEDLIN forms homodimers: characterisation of SEDLIN mutations and their interactions with transcription factors MBP1, PITX1 and SF1
BACKGROUND SEDLIN, a 140 amino acid subunit of the Transport Protein Particle (TRAPP) complex, is ubiquitously expressed and interacts with the transcription factors c-myc promoter-binding protein 1 (MBP1), pituitary homeobox 1 (PITX1) and steroidogenic factor 1 (SF1). SEDLIN mutations cause X-linked spondyloepiphyseal dysplasia tarda (SEDT). METHODOLOGY/PRINCIPAL FINDINGS We investigated the effects of 4 missense (Asp47Tyr, Ser73Leu, Phe83Ser and Val130Asp) and the most C-terminal nonsense (Gln131Stop) SEDT-associated mutations on interactions with MBP1, PITX1 and SF1 by expression in COS7 cells. Wild-type SEDLIN was present in the cytoplasm and nucleus and interacted with MBP1, PITX1 and SF1; the SEDLIN mutations did not alter these subcellular localizations or the interactions. However, SEDLIN was found to homodimerize, and the formation of dimers between wild-type and mutant SEDLIN would mask a loss in these interactions. A mammalian SEDLIN null cell-line is not available, and the interactions between SEDLIN and the transcription factors were therefore investigated in yeast, which does not endogenously express SEDLIN. This revealed that all the SEDT mutations, except Asp47Tyr, lead to a loss of interaction with MBP1, PITX1 and SF1. Three-dimensional modelling studies of SEDLIN revealed that Asp47 resides on the surface whereas all the other mutant residues lie within the hydrophobic core of the protein, and hence are likely to affect the correct folding of SEDLIN and thereby disrupt protein-protein interactions. CONCLUSIONS/SIGNIFICANCE Our studies demonstrate that SEDLIN is present in the nucleus, forms homodimers and that SEDT-associated mutations cause a loss of interaction with the transcription factors MBP1, PITX1 and SF1.This work was supported by the Oliver Bird Fund (Studentship No. RHE/00029/G), The Nuffield Foundation (J.J.), Arthritis Research Campaign (Grant ID
16438) (M.A.N. and R.V.T.), European Community Framework 7 programme grant TREAT-OA (HEALTH-F2-2008-00) (M.A.N. and R.V.T.) and the Medical Research
Council (J.J., M.A.N. and R.V.T.). J.J. was an Oliver Bird funded PhD student
Survey on the use of CAD-CAM technology by UK and Irish dental technicians
Statement of the problem Digital workflows (CAD/CAM) have been introduced in dentistry during recent years. No published information exists on dental technicians' use and reporting of this technology.Purpose The aim of this cross sectional survey was to identify the extent digital technology has infiltrated the workplace and to investigate the factors affecting the use of CAD-CAM technology by dental laboratory technicians within Ireland and the UK.Materials and methods A web-based questionnaire was composed (Opinio, Object Planet Inc. Oslo, Norway) and distributed to UK and Irish dental technicians. Answers to all questions were anonymous and grouped such that general information was gathered initially, followed by branching of the survey into two sections depending on whether or not the respondent worked with CAD-CAM technology. Results were compiled and statistical analysis (Fisher's Exact test, SPSS, IBM, Armonk, New York, USA) was performed in order to investigate any correlation between various demographic variables and the answers provided.Results The survey was distributed to 760 UK technicians and 77 Irish technicians. The total number of completed surveys was 105, which yielded a total response rate of 14%. Most technicians reported using some form of CAD/CAM aspect in the workflow, and this was more significant for technicians working in large laboratories. Most training received was company-led. Large laboratories were also significantly correlated with less outsourcing of CAD/CAM work and a change in dental material use leading to the increase of zirconia and the decrease of noble alloys. Dental technicians did not report any significant change in working relationships and staffing as a result of CAD/CAM incorporation. High initial investment cost was the most common reason quoted from non-users, along with the lack of such technology in their working environment
Selection of aphid prey by a generalist predator:do prey chemical defences matter?
1. For predators, prey selection should maximise nutrition and minimise fitness costs. In the present study, it was investigated whether a generalist predator [Chrysoperla carnea (Stephens) lacewing larvae] rejected harmful, chemically-defended prey [Brevicoryne brassicae (Linnaeus) aphids] when non-defended prey [Myzus persicae (Sulzer) aphids] were available. 2. It was tested: (i) whether consuming different prey species affects predator mortality; (ii) whether naïve predators reject chemically-defended prey while foraging when non-defended prey are available; (iii) whether the relative abundance of each prey affects the predator's prey choice; and (iv) whether predators learn to avoid consuming chemically-defended prey after exposure to both prey species. 3. Consumption of B. brassicae yielded greater C. carnea mortality than M. persicae consumption, but naïve C. carnea did not reject B. brassicae in favour of M. persicae during foraging. When presented at unequal abundances, naïve predators generally consumed each aphid species according to their initial relative abundance, although, predation of non-defended prey was less than expected when defended prey were initially more abundant, indicating a high consumption of B. brassicae impeded M. persicae consumption. With experience, C. carnea maintained predation of both aphid species but consumed more M. persicae than B. brassicae, indicating a change in behaviour. 4. Although prey choice by C. carnea may change with experience of available prey, prey chemical defences do not appear to influence prey choice by naïve predators. This inability to avoid harmful prey could facilitate wider, indirect interactions. Myzus persicae may benefit where high consumption of B. brassicae hinders predators in the short term, and in the long term, increases predator mortality
The calcilytic agent NPS 2143 rectifies hypocalcemia in a mouse model with an activating calcium-sensing-receptor (CaSR) mutation:relevance to autosomal dominant hypocalcemia type 1 (ADH1)
Autosomal dominant hypocalcemia type 1 (ADH1) is caused by germline gain-of-function mutations of the calcium-sensing receptor (CaSR) and may lead to symptomatic hypocalcemia, inappropriately low serum parathyroid hormone (PTH) concentrations and hypercalciuria. Negative allosteric CaSR modulators, known as calcilytics, have been shown to normalise the gain-of-function associated with ADH-causing CaSR mutations in vitro and represent a potential targeted therapy for ADH1. However, the effectiveness of calcilytic drugs for the treatment of ADH1-associated hypocalcemia remains to be established. We have investigated NPS 2143, a calcilytic compound, for the treatment of ADH1 by in vitro and in vivo studies involving a mouse model, known as Nuf, which harbors a gain-of-function CaSR mutation, Leu723Gln. Wild-type (Leu723) and Nuf mutant (Gln723) CaSRs were expressed in HEK293 cells and the effect of NPS 2143 on their intracellular calcium responses determined by flow cytometry. NPS 2143 was also administered as a single intraperitoneal bolus to wild-type and Nuf mice and plasma concentrations of calcium and PTH, and urinary calcium excretion measured. In vitro administration of NPS 2143 decreased the intracellular calcium responses of HEK293 cells expressing the mutant Gln723 CaSR in a dose-dependent manner, thereby rectifying the gain-of-function associated with the Nuf mouse CaSR mutation. Intraperitoneal injection of NPS 2143 in Nuf mice led to significant increases in plasma calcium and PTH without elevating urinary calcium excretion. These studies of a mouse model with an activating CaSR mutation demonstrate NPS 2143 to normalize the gain-of-function causing ADH1, and improve the hypocalcemia associated with this disorder
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Population characteristics and movement patterns of redband trout (Oncorhynchus mykiss) and mountain whitefish (Prosopium williamsoni) in the Crooked River, Oregon
Over the last decade, the Oregon Department of Fish and Wildlife (ODFW) has documented a precipitous decline in the Crooked River redband trout (Oncorhynchus mykiss) population, prompting this study to address potential factors contributing to the decline. There are two main goals to this project: (1) identify potential factors contributing to the reduction of the redband trout population in the Crooked River fishery and (2) provide management recommendations to all of the agencies responsible for managing the Crooked River that might effect a change in the redband trout population trend.
This thesis had three objectives: (1) evaluate the movement patterns of redband trout and mountain whitefish in the Crooked River below Bowman Dam, (2) monitor total dissolved gas levels (TDG) in the Crooked River to evaluate the incidence of supersaturated water and gas bubble disease in redband trout and mountain whitefish and (3) implement a more comprehensive population estimate survey to document both redband trout and mountain whitefish population densities.
Prior to this study, limited data existed on the distribution and movement patterns of redband trout and mountain whitefish in the Crooked River below Bowman Dam. Based on the results from the 2-year telemetry study, redband trout and mountain whitefish population exhibit a resident life history strategy and stay in the Wild and Scenic Section of the Crooked River below Bowman Dam. Two potential explanations for the observed population decline were plausible: the decline was actually a decline, or the fish moved to other sections of the Crooked River downstream of Bowman Dam. The telemetery study showed that redband trout and mountain whitefish stay within this section of river, thereby providing evidence against the explanation that the observed population decline was a result of movement of fish to other sections of river.
The total dissolved gas study demonstrated that gas saturation levels become elevated enough to cause gas bubble disease in the Crooked River below Bowman Dam. The gas saturation in the Crooked River is equivalent or higher than levels shown to produce gas bubble disease (GBD) in fishes. When flows exceed 600 cfs, the total dissolved gas saturation exceeds the maximum Oregon Department of Environmental Quality mandated level of 110% gas saturation in the Crooked River. Flows in excess of 600cfs are common during spring runoff events below Bowman Dam. From 1989-2009, flows exceeded 600 cfs in 13 of the 21 years and 1000 cfs in 10 of the 21 years. The past population effects of high flows and supersaturated waters on redband trout and mountain whitefish are difficult to quantify, but based on the hydrograph and the saturation curve, the years when gas bubble disease might have been present in fish can be predicted. Given the strong linear relationship between TDG and stream average daily discharge (r2 = 0.93), discharge itself can be used as a predictive tool for assessing TDG levels in the river. Based on the flow data from the USBOR gauging station and the gas saturation curve for the wild and scenic section of the Crooked River generated here, gas bubble disease was probably present in fish in 1993, 1996, 1997, 1998, 1999, and 2004.
The redband trout population density has varied considerably from year to year, with a peak observed in 1994 and the lowest point observed in 2006. A large increase in the number of redband trout per km occurred between 1993 and 1994, indicating that the density of fish can increase substantially in one year. The decline in redband trout density from 1994 to 2006 appears to be more gradual than the increase in density observed from 1993 to 1994. Since 2006, the redband trout population density appears to be increasing based on qualitative patterns.
One interesting finding was that in 2007, the mountain whitefish density was estimated to be 7 times greater than the redband trout population, in 2008 it was estimated to be 4 times greater, but in 2009, the mountain whitefish density was only marginally higher than the redband trout population. In the three years of this study, there appears to be a shift in the relative abundance of redband trout and mountain whitefish directly below Bowman Dam. The reduction in the mountain whitefish population density from 2007 to 2008 was not expected based on angler accounts of the increase in mountain whitefish population densities
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