Topological Defects and Interactions in Nematic Emulsions

Inverse nematic emulsions in which surfactant-coated water droplets are dispersed in a nematic host fluid have distinctive properties that set them apart from dispersions of two isotropic fluids or of nematic droplets in an isotropic fluid. We present a comprehensive theoretical study of the distortions produced in the nematic host by the dispersed droplets and of solvent mediated dipolar interactions between droplets that lead to their experimentally observed chaining. A single droplet in a nematic host acts like a macroscopic hedgehog defect. Global boundary conditions force the nucleation of compensating topological defects in the nematic host. Using variational techniques, we show that in the lowest energy configuration, a single water droplet draws a single hedgehog out of the nematic host to form a tightly bound dipole. Configurations in which the water droplet is encircled by a disclination ring have higher energy. The droplet-dipole induces distortions in the nematic host that lead to an effective dipole-dipole interaction between droplets and hence to chaining.Comment: 17 double column pages prepared by RevTex, 15 eps figures included in text, 2 gif figures for Fig. 1

Natural resistance : methods and mechanisms of enhancement in normal and tumor-bearing mice

This project examined methods of boosting innate resistance, enhancing those cells responsible for mediating "immune surveillance", i.e., Natural Killer (NK) cells. NK cells represent the first line of defense against neoplastic cells, to which they are spontaneously cytolytic, without having had prior exposure. This work aimed, firstly, to determine the effects on NK cells of administration of the interferon inducer, polyinosinic-polycytidylic acid (poly I:C) in irradiated leukemic mice given a bone marrow transplant, with or without the administration of the NK enhancer, tumor necrosis factor-alpha. The results demonstrated NK cell enhancement and prolonged life span of the poly I:C-treated, leukemic hosts. Secondly, this work aimed to study the hormone, melatonin (MLT), as well as a commercially prepared extract from the herb Echinacea purpurea, on NK cells. The role of these agents was assessed on NK cells in both normal and leukemic young adult mice. The results showed that both MLT and E. purpurea are NK enhancers when administered separately, suggesting prophylactic and therapeutic roles for these agents. The third aim of this project was to determine the effects of an E. purpurea treatment protocol on the numbers and function of NK cells in elderly mice. The age-related decline in NK cell numbers and function in mice is well documented in laboratory animals and corresponds with the increased frequency of tumors in these animals. This project has shown the effectiveness of the above treatments, especially those utilizing the herb extract from E. purpurea in stimulating NK cell numbers and cytolytic function in healthy and leukemic mice. In summary, the entire project has shown the NK enhancing effects and life span prolongation in leukemic mice by using cytokines, hormones and herbal extracts. The major contribution of this thesis has been to demonstrate that non-toxic, readily available and relatively inexpensive phytocompounds (herbal products) are not

Identification of Blowfly Species Using PCR

Forensic entomology is the use of insects in the criminal justice system. Blow flies (Diptera: Calliphoridae) are usually the first insects to arrive and oviposit (lay eggs) on carrion. Their early arrival makes the timing of blow fly oviposition critical for postmortem interval (PMI) calculations. To identify the exact species of blowfly from an egg mass or maggot, the specimen needs to be grown up through its life cycle for two weeks until it reaches its adult blowfly stage. Using egg masses that could be collected immediately, our goal was to shorten the identification process by analyzing the species differences in the cytochrome oxidase 1 (COX1) gene of the six most commonly found blowflies in the Northwest Indiana region. DNA was isolated from egg masses collected by the lab of Dr. Kristi Bugajski of Valparaiso University, and species were identified by sequencing of the DNA product. The goal of this investigation is to develop a protocol that could be done in a classroom setting, which would eliminate the need for sequencing as sequencing is expensive and not readily available on site. To accomplish this, six PCR primers have been developed that are specific to the six most common blowfly species in the area. After amplifying the isolated DNA with the six species specific PCR primers, agarose gel electrophoresis will be used to identify which species the DNA came from based on what primer amplified its DNA. If successful, the protocol will be published for use in a classroom setting

Identification of Blowfly Species Using PCR

Forensic entomology is the use of insects in the criminal justice system. Blow flies (Diptera: Calliphoridae) are usually the first insects to arrive and oviposit (lay eggs) on carrion. Their early arrival makes the timing of blow fly oviposition critical for postmortem interval (PMI) calculations. To identify the exact species of blowfly from an egg mass or maggot, the specimen needs to be grown up through its life cycle for two weeks until it reaches its adult blowfly stage. Using egg masses that could be collected immediately, our goal was to shorten the identification process by analyzing the species differences in the cytochrome oxidase 1 (COX1) gene of the six most commonly found blowflies in the Northwest Indiana region. DNA was isolated from egg masses collected by the lab of Dr. Kristi Bugajski of Valparaiso University, and species were identified by sequencing of the DNA product. The goal of this investigation is to develop a protocol that could be done in a classroom setting, which would eliminate the need for sequencing as sequencing is expensive and not readily available on site. To accomplish this, six PCR primers have been developed that are specific to the six most common blowfly species in the area. After amplifying the isolated DNA with the six species specific PCR primers, agarose gel electrophoresis will be used to identify which species the DNA came from based on what primer amplified its DNA. If successful, the protocol will be published for use in a classroom setting