Thesis (Ph. D.)--University of Chicago, Dept. of Neurobiology, Pharmacology and Physiology, June 2002. / Includes bibliographical references. Also available on the Internet.

Thesis (Ph.D.)--Baylor University, 2006. / Includes bibliographical references (p. 402-414).

The bursa of Fabricius is a central lymphoid organ essential for B cell development and generation of humoral immune responses in birds. The bursa is connected dorsally to the cloaca and continually “samples” the intestinal fluid phase for the presence of antigen. It is comprised of folds or plicae, which are seeded with individual follicles, where antigen processing and presentation occurs for B cell development as well as generation of antibody responses. The plicae are separated from the bursal lumen by interfollicular epithelium (IFE) and specific regions of follicle-associated epithelium (FAE). The FAE is comprised of M cell-like cells, which are specialized for transcytosis of antigen from the bursal lumen into underlying follicles. The uptake of particulate and soluble antigen in the bursa of Fabricius has been previously demonstrated, but how particle size affects their internalization within bursal FAE and the transport of particulate antigen into deeper follicles has not been explored. It has been shown that nanoparticles (NPs) ≤40 nm are most efficiently internalized by the epithelium of the murine intestine and vaginal tract. Therefore, we examined the uptake of 0.04 - 2 μm fluorescent polystyrene NPs in bursa at 1 hour or 6 hours after bursal administration to determine whether bursal epithelium is similarly constrained. Using immunofluorescence microscopy (IFM) and spectrofluorophotometry we found that NP uptake is inversely correlated with NP size. NPs ≤40 nm are most efficiently internalized by the bursal epithelium and bursal follicles, while NPs ≥500 nm are not effectively taken up by the bursal epithelium within 6 hours of administration. Moreover, once the size-limited capabilities of the bursal epithelium were established, we also found that bursal priming of chickens with 20 nm NPs conjugated to IMP-1, a protective antigen of an important avian pathogen Eimeria maxima, induces IMP-1-specific serum IgG following sub-cutandous boosting. We induced similar IMP-1-specific serum antibody responses in chickens primed bursally and sub-cutaneously boosted as those primed and boosted sub-cutaneously. Whether this route of immunization is able to elicit long-term protection must be investigated. A number of infectious diseases, including Infectious Bursal Disease Virus (IBDV), which directly targets the bursa of young birds and prevents the development of the immune system and causes mortality, are prevalent in the poultry industry. While vaccines exist for many of these diseases they confer only partial or incomplete protection; therefore, alternative vaccine strategies must be investigated. In addition, the bursa is an ideal in vivo model for the investigation of endocytic mechanisms for uptake of particulate antigen. Therefore, further characterizing the mechanisms of NP uptake at mucosal surfaces and their immunogenicity will be important for the development of NP-based mucosal vaccines for agriculturally relevant species such as poultry.

Total alkalinity (TA) is an important parameter in determining the uptake capacity of anthropogenic CO2 by the ocean. So far, oceanic carbon cycle models do not accurately represent TA and its variations. A spectrophotometric method was developed to measure variations of TA during two JGOFS cruises to the Northeast Atlantic in the early summer of 1990 and 1991 and in Emiliania huxleyi batch cultures. Short-term precision averaged around ± 0.1 %. A discrepancy of < 0.5% with coulometric results was observed in Na2COa standards. In natural seawater photometric TA was lower than potentiometric and calculated (pCOl, TC02) TA by about 1 and 2%, respectively. Discrepancies varied with hydrographic and/ or biological regime. Possible reasons for methodological shortcomings were considered, but without certified TA standards for different sample types, it was not possible to make an absolute statement about the accuracy of the methods involved. Combining the cruise results, photometric TA ranged by 90 and 20 p.eq kgSW-l in the surface mixed layer (SML) and at sub-thermocline depths, respectively. Some horizontal variation in the SML was related to salinity, but most of it could be linked to coccolithophorid growth during a bloom in 1991. Associated small-scale changes in TA of up to 40 J.leq kgSW-t occurred over 40 km. Independent estimates of seasonal net production of PlC and its relation to that of particulate organic carbon (POC) were established. Based on preceding investigations, a seasonal and latitudinal sequence of changes in surface TA was proposed which was corroborated by the photometric results from this study. The culture experiments revealed reductions in photometric TA which were half of those expected from parallel changes in measured PlC and nitrate concentrations. Proposed explanations for this included methodological shortcomings of all three methods and increases in final TA due to algal sulphate uptake and/or organic acid release. As the main conclusion, further targeted intercomparisons of TA methods are needed to identify the causes for errors in various TA methods in samples covering realistic hydrographic and biological ranges.

Made available in DSpace on 2014-06-11T19:23:25Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-28Bitstream added on 2014-06-13T18:09:32Z : No. of bitstreams: 1 peixoto_fc_me_jabo.pdf: 395583 bytes, checksum: 5301166e57d35ee4c63acfab04548a15 (MD5) / Sekita Agropecuaria / Com o objetivo de avaliar o crescimento e o acúmulo de macronutrientes em cenoura „Forto‟ e obter equações que melhores os representem, conduziu-se um experimento em São Gotardo (MG), de maio a setembro de 2004. As amostragens de plantas foram realizadas aos 40, 50, 60, 70, 80, 90, 100, 110 e 120 dias após a semeadura (DAS), para determinação da matéria seca e do acúmulo de macronutrientes em folhas e raiz da cenoura. Aos 40 DAS, cinco dias após ter sido realizado o desbaste, a planta de cenoura „Forto‟ apresentava 0,18 g e 0,04 g em matéria seca de folhas (MSF) e de raiz (MSR), respectivamente. A partir de então, até 88 DAS, a partição de matéria seca mostrou-se favorável na parte aérea. A MSR de cenoura foi pequena até dois terços do cultivo, ou seja, 80 DAS. A partir de então, verificou-se que a quantidade de matéria alocada nesta parte da planta teve forte incremento, ultrapassando, aos 88 DAS, a quantidade de MSF. O acúmulo de nutrientes foi pequeno até 60 DAS, coincidindo com o período de menor acúmulo de matéria seca. A ordem decrescente de macronutrientes acumulados pela cultura foi K, N, Ca, P, S e Mg, nas quantidades de 906,7; 438,0; 155,5; 87,4; 58 e 37,6 mg planta-1, respectivamente. A raiz participou com 60,5% do acúmulo de N, 86,1% de P, 58,0% de K, 25,5% de Ca, 55,6% de Mg e 65,5% de S. / In order to quantify the growth and accumulation of macronutrients of carrot 'Forto', and obtain equations that best represent them, it was carried out experiment in the São Gotardo (MG), from May to September of 2004. Samples of plants were taken at 40, 50, 60, 70, 80, 90, 100, 110 and 120 days after sowing (DAS) to determine dry matter and accumulation of macronutrients in leaves and roots of carrot. At 40 DAS, five days after thinning, the plants had 0.18 g and 0.04 g of leaves dry mass (LDM) and root dry mass (RDM), respectively. From then, until 88 DAS, the partitioning of dry matter in the aerial part were more pronounced. The RDM was low until 80 DAS, which corresponded to two thirds of the crop cycle, from when the amount of material allocated in this part of the plant had strong growth surpassing at 88 DAS the amount of LDM. The nutrient accumulation was small until 60 DAS, coinciding with the period of lower dry matter accumulation in the plant. The order of decreasing macronutrient accumulation by the plant was K, N, Ca, P, S e Mg, in the amounts of 906.7, 438.0, 155.5, 87.4, 58.0 and 37.6 mg plant-1, respectively. The commercial root participated with 60.5% of the accumulation of N, 86.1% of P, 58.0% of K, 25.5% of Ca, 55.6% of Mg and 65.5% of S.

Made available in DSpace on 2014-10-09T12:50:34Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:59:01Z (GMT). No. of bitstreams: 1 00408.pdf: 1075141 bytes, checksum: 54b845712f2166aa73f4a1b2faffd2c2 (MD5) / Dissertacao (Mestrado) / IEA/D / Faculdade de Ciencias Farmaceuticas, Universidade de Sao Paulo - CF/USP

Made available in DSpace on 2014-10-09T12:50:34Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:59:01Z (GMT). No. of bitstreams: 1 00408.pdf: 1075141 bytes, checksum: 54b845712f2166aa73f4a1b2faffd2c2 (MD5) / Dissertacao (Mestrado) / IEA/D / Faculdade de Ciencias Farmaceuticas, Universidade de Sao Paulo - CF/USP

No description available.

Attention worldwide has been placed towards reducing the global carbon footprint. To this end the scientific community has been involved in improving many of the available methods of carbon capture and storage (CCS). CCS involves scrubbing flue gases of greenhouse gases and safely storing them deep underground. MOFs, a family of functionally tunable three dimensional nanoporous frameworks, have been shown to adsorb gases with great selectivity and capacity. Investigating these frameworks using computational simulations, although faster than in-lab synthetic methods, involves a tedious and meticulous input preparation process which is subject to human error. This thesis presents Dave's Occupancy Automation Package (DOAP),a software which provides a means to automatically determine the gas uptake of many three dimensional frameworks. By providing atomic coordinates for a unit simulation cell, the software acts to performs the necessary calculations to construct and execute a Grand Canonical Monte Carlo simulation, determining the gas uptake in a metal organic framework. Additionally an analysis of different convergence assessment tests for describing the end point of the GCMC simulation is presented.

Organic conducting polymer, poly(3,4-ethylene dioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS), is widely recognized for its electro-actuation mechanism and is used in flexible electronics. Its high potential as actuator is based on a strong coupling between chemical, mechanical and electrical properties which directly depends on external stimuli. There is no model today to describe the interplay between moisture absorption, mechanical expansion and electrical stimulus. Elucidating the role of each component in the effective actuation properties is needed to further optimize and tailor such materials. The objective of this thesis is to develop a macroscopic model to describe water sorption kinetics of the PEDOT:PSS film. We used gravimetric analysis of pure PEDOT:PSS film of three different thicknesses to investigate absorption kinetics over a broad range of temperatures and relative humidity. Our results revealed that the moisture uptake of PEDOT:PSS film does not follow Fickian diffusion law due to the retained amount of water after desorption process. We used an existing diffusionreaction model to describe this behavior, and COMSOL Multiphysics and MATLAB software programs to implement it. We observed that the generic model we used in our work could predict polymer behavior with 95% accuracy. However, our model was not able to properly represent the data at very high relative humidity at low temperature, which was attributed to the excessive swelling of the film. Also, we examined a relation between the moisture content of PEDOT:PSS and its mechanical strain and electrical conductivity. The results presented here are the first step towards a general multiphysics electro-thermo-mechanical description of PEDOT:PSS based actuators.