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Preparative-scale protein separations have always been critical to the advancement of the life sciences. Among preparative-scale separation techniques, isoelectric trapping (IET) promises efficient separations and high production rates. This dissertation focuses on the improvement of two aspects of preparative-scale IET protein separations: the instrumentation used and the monitoring of the separation. The first aspect (preparative-scale) is the IET device: the improvement of a multicompartmental electrolyzer (MCE) to increase the efficiency and production rate of IET separations. The redesign focused on three major areas: (1) the sealing system, (2) the configuration of the liquid flow path, and (3) the cooling system. The second aspect (analytical-scale) is the monitoring of the IET separation: the design and manufacture of durable surface-modified capillaries which provide controlled, variable anodic and cathodic electroosmotic flow (EOF) to help develop, plan, and monitor the IET separations.

Preparative-scale protein separations have always been critical to the advancement of the life sciences. Among preparative-scale separation techniques, isoelectric trapping (IET) promises efficient separations and high production rates. This dissertation focuses on the improvement of two aspects of preparative-scale IET protein separations: the instrumentation used and the monitoring of the separation. The first aspect (preparative-scale) is the IET device: the improvement of a multicompartmental electrolyzer (MCE) to increase the efficiency and production rate of IET separations. The redesign focused on three major areas: (1) the sealing system, (2) the configuration of the liquid flow path, and (3) the cooling system. The second aspect (analytical-scale) is the monitoring of the IET separation: the design and manufacture of durable surface-modified capillaries which provide controlled, variable anodic and cathodic electroosmotic flow (EOF) to help develop, plan, and monitor the IET separations.

The classical isoelectric trapping (IET) technique, using the multicompartment electrolyzer (MCE), has been one of the most successful electrophoretic techniques in preparative-scale protein separations. IET is capable of achieving high resolution discrimination of proteins, by isolating proteins in between buffering membranes, in their isoelectric state. However, due to the inherent nature of the IET process, IET has suffered several shortcomings which have limited its applicability. During a classical IET separation, a protein gets closer and closer to its pI value, thus the charge of the protein gets closer and closer to zero. This increases the likelihood of protein precipitation and decreases the electrophoretic velocity of the protein, thus making the separation very long. Furthermore, the problems are aggravated by the fact that the instrumentation currently used for IET is not designed to maximize the efficiency of electrophoretic separations. To address these problems, a new approach to IET has been developed, pH-biased IET. By controlling the solution pH throughout the separation, such that it is not the same as the protein’s pI values, the problems of reduced solubility and low electrophoretic migration velocity are alleviated. The pH control comes from a novel use of isoelectric buffers (also called auxiliary isoelectric agents or pH-biasers). The isoelectric buffers are added to the sample solution during IET and are chosen so that they maintain the pH at a value that is different from the pI value of the proteins of interest. Two new pieces of IET instrumentation have been developed, resulting in major improvements in protein separation rates and energy efficiency. A variety of separations, of both small molecules and proteins, have been successfully performed using the pH-biased IET principle together with the new instrumentation.

n order to accurately assess the status of the cheetah Acinonyx jubatus it is necessary to obtain data on numbers and demographic trends. However, cheetahs are notoriously difficult to survey because they occur at very low population densities and are often shy and elusive. In South Africa the problem is further complicated in areas where land is privately owned, restricting access, with dense bush and cheetahs that are frequently persecuted. Cheetahs are individually identifiable by their unique spot patterns, making them ideal candidates for capture–recapture surveys. Photographs of cheetahs were obtained using four camera traps placed successively at a total of 12 trap locations in areas of known cheetah activity within a 300 km² area in the Thabazimbi district of the Limpopo Province. During 10 trapping periods, five different cheetahs were photographed. These results were used to generate capture histories for each cheetah and the data were analysed using the capture–recapture software package CAPTURE. Closure tests indicated that the population was closed (P = 0.056). The Mh model was used to deal with possible heterogeneous capture probabilities among individual cheetahs. Closure tests did not reject the model assumption of population closure (P = 0.056).TheMh model produced a capture probability of 0.17 with an estimate of 6–14 cheetahs (P = 0.95) and a mean population size of seven cheetahs (S.E. = 1.93). These results are promising and will be improved with employment of more camera traps and sampling a larger area.

Thesis (M.S.)--Brigham Young University. Dept of Plant and Wildlife Sciences, 2007. / Includes bibliographical references.

Thesis (M.S.)--University of Delaware, 2007. / Principal faculty advisor: Dewey M. Caron, Dept. of Entomology & Wildlife Ecology. Includes bibliographical references.

Pore network models have served as a predictive tool for soil and rock properties with a broad range of applications, particularly in oil recovery, geothermal energy from underground reservoirs, and pollutant transport in soils and aquifers [39]. They rely on the representation of the void space within porous materials as a network of interconnected pores with idealised geometries. Typically, a two-phase flow simulation of a drainage (or imbibition) process is employed, and by averaging the physical properties at the pore scale, macroscopic parameters such as capillary pressure and relative permeability can be estimated. One of the most demanding tasks in these models is to include the possibility of fluids to remain trapped inside the pore space. In this work I proposed a trapping rule which uses the information of neighboring pores instead of a search algorithm. This approximation reduces the simulation time significantly and does not perturb the accuracy of results. Additionally, I included spatial correlation to generate the pore sizes using a matrix decomposition method. Results show higher relative permeabilities and smaller values for irreducible saturation, which emphasizes the effects of ignoring the intrinsic correlation seen in pore sizes from actual porous media. Finally, I implemented the algorithm from Raoof et al. (2010) [38] to generate the topology of a Fontainebleau sandstone by solving an optimization problem using the steepest descent algorithm with a stochastic approximation for the gradient. A drainage simulation is performed on this representative network and relative permeability is compared with published results. The limitations of this algorithm are discussed and other methods are suggested to create a more faithful representation of the pore space.

An ion trap has been constructed that creates a potential well suitable for confining ions with the space charge of an electron cloud. The trap uses the concept of artificially structured boundaries, regions of overlapping electric and magnetic fields, to confine particles in a relatively field free volume. Measurements are presented from the build-up of ionized molecular hydrogen over time. Molecular hydrogen is introduced into the confinement volume by direct electron bombardment ionization of neutral background H2 leaked into the trap. Detailed analysis of the data is conducted using particle-in-cell simulations of trap operation and rate mechanics analysis. Pressure dependent estimates of ion lifetimes in the trap are on the order of milliseconds. Along with discussion of the trap a full introduction to the particle-in-cell technique is conducted through an original code implementation.

The elusive and nocturnal nature of the ocelot Leopardus pardalis poses difficulty in gaining basic information on demographic parameters needed to better inform conservation. My study used camera trapping data from long-term monitoring of ocelot populations on six different protected areas in Belize over a time span ranging from 1 to 12 years, with 1,700 ocelot detections in 65,157 total trap nights. I used classical and spatially explicit methods, including multi-session robust design, to estimate and compare ocelot density and survival across sites and time. Full likelihood single session models estimated densities ranging from 6.4 - 22.5 individuals/100km2 in the broadleaf forested sites. Robust design models estimated densities from 8.8 - 22.8 individuals/100 km2 and ocelots had high annual survival (71-79%) in 2 broadleaf sites. Contrary to predictions, robust design models had higher precision than full likelihood models less than half the time. Spatially explicit models estimated density ranging between 7.2 – 22.0 individuals/100 km2 in broadleaf sites, and much lower estimates at 0.9 individuals/100 km2 in the pine forest site. Accounting for sex in spatially explicit methods, which directly incorporate locations of captures into the model, increased precision in density estimates by reducing individual heterogeneity in capture probability. The spatial models also demonstrated that males moved larger distances than females and had slightly higher detection rates. Ocelot populations remained relatively stable over time at the long term sites. My study produced methodologically rigorous abundance/density estimates for ocelots in Belize and the first ever ocelot survival estimates. / Master of Science