Solution-Phase Assembly of Nanoparticles and Amphiphilic Polymers: Controlling the Morphology From Vesicles to Micelles

Advances in nanocomposite solution-phase assembly involve understanding fundamentally how nanoparticles influence the self-assembly structure of block copolymers. Researchers have shown that self-assembly of amphiphilic block copolymers and nanoparticles offers a powerful route to the formation of multifunctional nanocomposites for medical imaging and drug delivery applications. The possible combinations of various types of nanoparticles and polymers are numerous, but until recently the major factors that control these structures have not been well understood. Work done by others and the work in this thesis have shown that the arrangement of nanoparticles within a polymer matrix affects the composite material\u27s properties in ways not seen in the two separate systems. An important discovery during my thesis work was the formation of polymer vesicles (polymersomes), densely packed with iron oxide nanoparticles in the vesicle walls. I demonstrated that, while well-established self-assembly principles of amphiphilic block copolymers provide a valuable guideline for the preparation of nanoparticle-encapsulating block copolymer assemblies, these principles do not directly apply to the simultaneous self-assembly of nanoparticles and block copolymers. This point is especially important when it is desirable to achieve high density nanoparticle loading and specific arrangement of nanoparticles in polymer assemblies. My work described within this thesis shows how the incorporation of nanoparticles affects the self-assembly structure and how to control the morphology of nanoparticle-encapsulating polymer assemblies

The Establishment and Administration of Pension Plans in the Labor Relations Process

The purpose of this article is to analyze the role of pension plans\u27 in the labor relations process. The earliest pension plans had their origin in the early nineteenth century and were pioneered by fraternal associations established and operated by and for the employees. The advent of unions on the labor scene resulted in the union, instead of the fraternal association, administering the program. As for employer pension plans, the union leaders feared that such programs were only a devious employer\u27s device to prevent unionization. Thus, prior to World War II, employer pension plans were usually unilaterally instituted. However, beginning in 1942 collective bargaining for pension plans began to achieve major momentum. Among the circumstances which combined to produce this result were the tax deduction allowed the employer for contribution to these programs; the National War Labor Board policy of freezing cash pay raises while increasing compensation in the form of fringe benefits; and decisions of the National Labor Relations Board, sustained by the courts, that pensions were properly within the statutory scope of the employer\u27s duty to bargain

Using Satellite Image Analysis for Locating Prehistoric Archaeological Sites in Alaska\u27s Central Brooks Range

In this pilot study, we apply satellite image analysis to archaeological site prospection in Alaska\u27s Brooks Range. Our goal was to test whether satellite remote sensing, which has been successful in locating large archaeological features associated with sedentary peoples, could be applied to arctic interior sites associated with mobile hunter–gatherers. In particular, we strove to develop a relatively straightforward and inexpensive model using existing data which could be used to help guide archaeology surveys. Using 1-m resolution IKONOS imagery of Lake Matcharak along the upper Noatak River, we produced a Normalized Difference Vegetation Index (NDVI) and tasseled cap transformation of the study area and stacked these five vegetation indices into one image. We then applied unsupervised and supervised classifications to the image first, to test for the presence of a site-specific spectral class and second, determine the nature of that class. Through a visual analysis of the unsupervised classification, a spectral phenomenon was seen to co-occur with archaeological sites in the study area. The supervised classification provided a high-resolution land cover map used to identify the signature as the ecotone between un-vegetated sediments and dense willow (Salix sp.) stands. Dense willow stands along the Lake Matcharak shore visually correlate with most of the known archaeological sites, possibly reflecting landform and/or vegetation characteristics thatwould have appealed to past inhabitants. The methods described here could contribute to building better survey strategies and archaeological predictive models for elsewhere in the Brooks Range and Alaska

Significance of the pericardium in human subjects: Effects on left ventricular volume, pressure and ejection

To assess the effect of the pericardium, left ventricular systolic function and diastolic compliance were studied in 15 patients before and after pericardiotomy during coronary artery surgery. Using first pass radionuclide angiography, curves for left ventricular systolic function (stroke work versus end-diastolic volume) and a measure of diastolic compliance (pulmonary capillary wedge pressure versus end-diastolic volume) were generated by changing body position to alter venous return. Left ventricular end-diastolic volume ranged from 41 to 111 ml/m2and pulmonary capillary wedge pressure from 0 to 24 mm Hg.No significant changes were found in blood pressure (150/83 to 148/82 mm Hg), heart rate (66.7 to 67.1 beats/min), cardiac index (2.38 to 2.41 liters/min per m2), ejection fraction (0.56 to 0.54), end-systolic volume index (31.4 to 32.2 ml/m2), end-diastolic volume index (65.9 to 69.5 ml/m2) or pulmonary capillary wedge pressure (7.5 to 7.3 mm Hg). The pericardium did not affect the curves relating stroke work and end-diastolic volume or those relating pulmonary capillary wedge pressure and end-diastolic volume. Thus, when filling pressure and volume are normal or only moderately elevated, the pericardium does not appear to affect left ventricular systolic function or diastolic compliance in patients

Novel dry powder preparations of whole inactivated influenza virus for nasal vaccination

The purpose of these studies was to enhance mucosal and systemic antibody production in response to increased local residence time of a whole inactivated influenza virus administered as a dry powder nasal vaccine formulation. Spray-freeze-drying (SFD) particles suitable for nasal delivery were characterized for physico-chemical properties and stability. Mucoadhesive compounds (MA) were characterized for their effects on nasal residence time of vaccine powders in rats compared with published in vitro data and elicited immune responses. SFD particles (D50=26.9µm) were spherical with a specific surface area of 1.25 m2/g. Thermal analysis indicated SFD powders were amorphous and demonstrated improved stability with respect to liquid formulations under various storage conditions. In vitro physico-chemical studies and in vivo scintigraphic imaging experiments indicated sodium alginate (SA) and carboxymethylcellulose-high molecular weight (CMC-HMW) powder formulations most significantly increased residence time in Brown Norway rats. Intramuscular delivery provided equivalent serum antibody titers to intranasal (IN) powder without MA, in the presence of CMC-HMW, SA, and hydroxypropyl methylcellulose (HPMC-HMW) after initial dosing and all formulations except IN powder with chitosan after boosting. IN liquid provided equivalent serum antibody titers to all IN powders after the initial vaccination and significantly greater serum antibody titers than IN powder with chitosan after boosting. Trends were consistent between residence time studies and immune response; however, no statistically significant differences between powder and liquid formulations were observed. It was concluded that enhanced serum and mucosal antibody responses were elicited by a dry powder nasal vaccine, specifically, administered in the presence of sodium alginate

Contrasting Development of Canopy Structure and Primary Production in Planted and Naturally Regenerated Red Pine Forests

Globally, planted forests are rapidly replacing naturally regenerated stands but the implications for canopy structure, carbon (C) storage, and the linkages between the two are unclear. We investigated the successional dynamics, interlinkages and mechanistic relationships between wood net primary production (NPPw) and canopy structure in planted and naturally regenerated red pine (Pinus resinosa Sol. ex Aiton) stands spanning ≥ 45 years of development. We focused our canopy structural analysis on leaf area index (LAI) and a spatially integrative, terrestrial LiDAR-based complexity measure, canopy rugosity, which is positively correlated with NPPw in several naturally regenerated forests, but which has not been investigated in planted stands. We estimated stand NPPw using a dendrochronological approach and examined whether canopy rugosity relates to light absorption and light–use efficiency. We found that canopy rugosity increased similarly with age in planted and naturally regenerated stands, despite differences in other structural features including LAI and stem density. However, the relationship between canopy rugosity and NPPw was negative in planted and not significant in naturally regenerated stands, indicating structural complexity is not a globally positive driver of NPPw. Underlying the negative NPPw-canopy rugosity relationship in planted stands was a corresponding decline in light-use efficiency, which peaked in the youngest, densely stocked stand with high LAI and low structural complexity. Even with significant differences in the developmental trajectories of canopy structure, NPPw, and light use, planted and naturally regenerated stands stored similar amounts of C in wood over a 45-year period. We conclude that widespread increases in planted forests are likely to affect age-related patterns in canopy structure and NPPw, but planted and naturally regenerated forests may function as comparable long-term C sinks via different structural and mechanistic pathways

Nimbus-7 Earth radiation budget calibration history. Part 1: The solar channels

The Earth Radiation Budget (ERB) experiment on the Nimbus-7 satellite measured the total solar irradiance plus broadband spectral components on a nearly daily basis from 16 Nov. 1978, until 16 June 1992. Months of additional observations were taken in late 1992 and in 1993. The emphasis is on the electrically self calibrating cavity radiometer, channel 10c, which recorded accurate total solar irradiance measurements over the whole period. The spectral channels did not have inflight calibration adjustment capabilities. These channels can, with some additional corrections, be used for short-term studies (one or two solar rotations - 27 to 60 days), but not for long-term trend analysis. For channel 10c, changing radiometer pointing, the zero offsets, the stability of the gain, the temperature sensitivity, and the influences of other platform instruments are all examined and their effects on the measurements considered. Only the question of relative accuracy (not absolute) is examined. The final channel 10c product is also compared with solar measurements made by independent experiments on other satellites. The Nimbus experiment showed that the mean solar energy was about 0.1 percent (1.4 W/sqm) higher in the excited Sun years of 1979 and 1991 than in the quiet Sun years of 1985 and 1986. The error analysis indicated that the measured long-term trends may be as accurate as +/- 0.005 percent. The worse-case error estimate is +/- 0.03 percent