6,107 research outputs found

    Reduction and analysis of data collected during the electromagnetic tornado experiment

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    Progress is reviewed on the reduction and analysis of tornado data collected on analog tape. The strip chart recording of 7 tracks from all available analog data for quick look analysis is emphasized

    City Taxes and Property Tax Bases

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    This paper investigates the simultaneous relationship between tax rates and city property tax bases using data for 86 large U.S. cities in 1967, 1972, 1977, and 1982. We find that a 10 percent increase in the city's property tax rate decreases the city's tax base by about 1.5 percent. In addition, local income taxes and taxes levied by overlying jurisdictions (such as county and state governments) also have negative impacts on the city's property tax base. Local sales taxes, in contrast, appear to have little impact. We conclude that taxes affect local property values more than is typically implied by previous studies that have investigated the impacts of state and local taxes on firms' location decisions.

    Determination of mass outflow from a thunderstorm complex using ATS 3 pictures

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    Satellite cloud photography for determining mass outflow and tornado formatio

    Editor\u27s Note: Volume 1, Issue 2

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    U. S. labor supply in the twenty-first century

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    The American labor force will be transformed as the twenty-first century unfolds, a change that will confront policymakers and business firms with new challenges and new opportunities. The impending slowdown of labor force growth that will accompany the retirement of the baby boom generation already is playing a central role in national debates over the future solvency of Social Security and Medicare, as well as U.S. immigration policies. But labor supply changes will be influenced by other dimensions as well. In the coming decades, American workers are likely to be, on average, older and better educated than today’s labor force. The globalization of labor markets is already opening new employment opportunities for some Americans and changing the wage rates paid to others. The production technologies and personnel policies adopted by tomorrow’s firms will undoubtedly reflect the numbers and types of workers available for employment.Labor supply ; Baby boom generation

    Developing digital interventions: a methodological guide.

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    Digital interventions are becoming an increasingly popular method of delivering healthcare as they enable and promote patient self-management. This paper provides a methodological guide to the processes involved in developing effective digital interventions, detailing how to plan and develop such interventions to avoid common pitfalls. It demonstrates the need for mixed qualitative and quantitative methods in order to develop digital interventions which are effective, feasible, and acceptable to users and stakeholders

    An investigation into the structure of a turbulent plane jet.

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    PhDAn experimental investigation into the structure of the plane jet in a moving airstream has been made. The majority of the measurements have been made in a jet exhausting into a slow moving airstream providing an example of a possible self-preserving flow. The experiments showed that the flow does, in fact, become self-preserving at distances downstream from the jet nozzle of thirty jet nozzle width. The distributions of the turbulent intensities across the jet in the self-preserving region of the flow are shown to be similar to those found in the plane wake. However, the turbulent energy balance for the two flows appears to be quite different. Some measurements of the eddy structure indicate that shear carrying eddies are among the largest eddies in the flow and are also partly responsible for the intermittency phenomenon. The unsteady irrotational flow outside the jet is shown to be adequately described by the theories of Phillips (1955) and Stewart (1956). Some comments are made on the applicability of the various simple theories of turbulence to the plane jet and the interesting, though not necessarily significant, point emerges that the Prandtl Mixing Length theory gives the beat description of the flow structure. Additional measurements in jets in fast moving airstreams show that the change from a jet to a wake type of turbulence structure takes place at a very slow rate. Several simple theories were developed to account for the spread of a plane jet in a moving airstream but none of then proved wholly adequate. Apart from the main investigation, some work on the problem of measurements in a turbulent flow in discussed. Aspects of both hot wire anemometer theory and static pressure measurements are re-appraised

    Uptake and transport of orally-deliverable drugs across caco-2 cell monolayers:the effect of lipid formulations

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    The aim of this thesis is to investigate the physicochemical parameters which can influence drug loading within liposomes and to characterise the effect such formulations have on drug uptake and transport across in vitro epithelial barrier models. Liposomes composed of phosphatidylcholine (PC) or distearoyl phosphatidylcholine (DSPC) and cholesterol (0, 4, 8, 16 µM) were prepared and optimised in terms of drug loading using the hand-shaking method (Bangham et al., 1965). Subsequently, liposomes composed of 16 µM PC or DSPC and cholesterol (4 µM) were used to monitor hydroxybenzoate release and transport from Iiposomes. The MIT (3[4,5-Dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) and crystal violet assays were employed to determine toxicity of the Iiposome. formulations towards the Caco-2 cell line, employed to model the epithelial barrier in vitro. Uptake and transport of mannitol, propranolol, glutamine and digoxin was measured in the presence and absence of Iiposome formulations to establish changes in absorption resulting from the presence of lipid formulations. Incorporation of the four hydroxybenzoates was shown to be influenced by a number of factors, including liposome composition and drug conformation. Methyl hydroxybenzo.ate (MP) was incorporated into the bilayer most effectively with percentage incorporation of 68% compared to 45% for butyl hydroxybenzoate (BP), despite its increased Iipophilicity. This was attributed to the decreased packing ability of BP within the hydrocarbon core of the lipid bilayer compared to MP. Release studies also suggested that the smaller MP was more strongly incorporated within the lipid bilayer with only 8% of the incorporated solute being released after 48-hours compared to 17% in the case of BP. Model transport studies were seen to reflect drug release profiles from the liposome bilayers with significantly (p < 0.01) higher amounts of BP partitioning from the liposome compared to MP, Caco-2 cell viability was maintained above 86% in the presence of all Iiposome formulations tested indicating the liposome formulations are non-toxic towards Caco-2 cells. Paracellular (apical-to-basolateral) transport of mannitol was significantly increased in the presence of DSPC, PC / DSPC:Cholesterol (16:4 µM; 1000 µg). Glutamine uptake and transport via the carrier-mediated route was Significantly (p < 0.01) increased in the presence of PC I DSPC:Cholesterol (16:0; 16:4 µM). Digoxin apical-to-basolateral transport was significantly increased (p < 0,01) in the presence of PC / DSPC:Cholesterol (16:0; 16:4 µM); thus reducing digoxin efflux via P-glycoprotein. In contrast, PC:ChoJesterol (16:0; 16:4 µM) significantly (p < 0.01) decreased propranolol uptake via the passive transcellular route. Bi-directional transport of propranolol was significantly (p < 0,01) decreased in the presence of PC/DSPC:Cholesterol (16:0; 16:4 µM). The structure of a solute is an important determinant for the incorporation and release of a solute from liposome formulations. PC, DSPC and cholesterol liposome formulations are nontoxic towards Caco-2 cell monolayers and improved uptake and transport of mannitol, glutamine. and digoxin across Caco-2 cell monolayers; thus providing a potential alternative delivery vehicle
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