There is a debate in the philosophy of time over the status of non-present entities. Do these things exist, and if so, what sorts of things are they? Recently, the debate has split into two groups, presentists and eternalists. Presentists hold that no past or future things exist now. Socrates does not now exist, though he did in the past; my future daughter does not now exist, though she may in the future. Ontologically, the present is distinct, serving to demarcate all that currently has existence. As far as the eternalist is concerned, all entities - whether past, present, or future - are equally real. If it was, is, or will be, it can be found in the eternalist picture of time. As such, there is no distinct present at which some entities exist while others do not; rather, everything enjoys the same ontological status. I will be concerned to offer an assessment of the presentist view. Common objections against presentism will be examined, amplified, and answered where appropriate. I will not examine the arguments in favor of the presentist view. Rather, I wish to describe why it is that the eternalist feels compelled to deny presentism. Ultimately, my goal will be to show that although presentism survives some of the current objections raised against it, it does not survive them all. Presentism is an interesting, but ultimately unsatisfactory view. There is a modified form of presentism (call it presentism*) that can meet the objections raised against the original position, and after noting some of the objections raised against presentism, I will sketch the outlines of presentism* in some detail. I intend to show that presentism* is able to retain what is most valuable about presentism, while also withstanding certain objections that the latter view could not.

The thesis focuses on the study of asymmetric multiple quantum wells(AMQWs) grown by molecular beam epitaxy (MBE) in the Riber Compact 21T MBE system. We investigate AMQW structures in which the well width is varied but the material compositions of the wells and the barriers are kept constant. Also, we have investigated AMQWs with p-type modulation doping at the barrier region and the AMQWs of different well widths without changing the well compositions. The AMQW samples are obtained the emission spectra by using photoluminescence (PL), electroluminescence (EL), photo-current and photoreflectance (PR) in the experiments. Also, The AMQW samples (AMQ100-70-40 and AMQ-100-MD70-40) are fabricated into laser diodes to obtain the characteristics of device in this study. The threshold current density Jth of laser diode is measured about 2 kA/cm2.The internal quantum efficiency £bi and the absorption £\ of AMQ-100-70-40 are 34.7% and 9.47 cm-1 respectively. The internal quantum efficiency £bi and the absorption £\ of AMQ-100-MD70-40 are 22.2% and 10.56 cm-1 respectively. Moreover, we present the InGaAsP AMQW samples grown by MOCVD to compare with the InGaAs/InAlGaAs AMQW samples. The broad-band property is valuable for application of optical communication. It is highly desirable to have broadly tunable lasers and broad-band semiconductor optical amplifiers (SOAs) in the 1.3 or 1.55£gm to handle more number of channels increasing the volume of information traffic for future optical communication networks. The band-band light source is also desirable in medical science for the optical coherence tomography (OCT).

There is a debate in the philosophy of time over the status of non-present entities. Do these things exist, and if so, what sorts of things are they? Recently, the debate has split into two groups, presentists and eternalists. Presentists hold that no past or future things exist now. Socrates does not now exist, though he did in the past; my future daughter does not now exist, though she may in the future. Ontologically, the present is distinct, serving to demarcate all that currently has existence. As far as the eternalist is concerned, all entities - whether past, present, or future - are equally real. If it was, is, or will be, it can be found in the eternalist picture of time. As such, there is no distinct present at which some entities exist while others do not; rather, everything enjoys the same ontological status. I will be concerned to offer an assessment of the presentist view. Common objections against presentism will be examined, amplified, and answered where appropriate. I will not examine the arguments in favor of the presentist view. Rather, I wish to describe why it is that the eternalist feels compelled to deny presentism. Ultimately, my goal will be to show that although presentism survives some of the current objections raised against it, it does not survive them all. Presentism is an interesting, but ultimately unsatisfactory view. There is a modified form of presentism (call it presentism*) that can meet the objections raised against the original position, and after noting some of the objections raised against presentism, I will sketch the outlines of presentism* in some detail. I intend to show that presentism* is able to retain what is most valuable about presentism, while also withstanding certain objections that the latter view could not.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1961. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 167-176).

Thesis (M.S.)--Springfield College, 2004. / Includes bibliographical references. Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1971. / Vita. Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--Springfield College, 2004. / Includes bibliographical references.

This research is aimed at finding empirical evidence to support the relationship between Broad-based Black Economic Empowerment (BBBEE) compliance and the financial performance of South African companies on the JSE. An independent measure of the BEE score was obtained from the Empowerdex Top Empowerment Companies (TEC) ranking from 2004 to 2009. 14 sectors on the JSE were selected to ensure inclusion of all major industries in South Africa. A total of 209 companies were selected, and the multivariate exploratory technique of Cluster Analysis was used. The predictor variable of the company’s BEE status was then compared to a number of financial performance indicators such as annual share price, price-tobook value ratio and the price-to-earnings ratio (i.e. the outcome variables). By standardising the variables of the BEE score and using Compound Annual Growth Rate (CAGR), the k-means Clustering method yielded four interpretable clusters with 15, 64, 95 and 35 companies respectively. The finding indicate that only in the case of the cluster of companies that increased it’s BEE score, were all three profitability measures significantly different and, according to the means, in the direction of higher profitability. However, there were no significant differences in the results to support the proposition that low-BEE scores of companies had a negative impact on their profitability and their firm’s value over time. / Dissertation (MBA)--University of Pretoria, 2010. / Gordon Institute of Business Science (GIBS) / unrestricted

This study endeavoured to establish, specifically, the effectiveness of enterprise development initiatives within the McCarthy Ltd franchised dealer network and also to understand their low occurrence within the group. Effective implementation of enterprise development initiatives within McCarthy Ltd franchised dealer network would also mean compliance to the BBBEE codes of good practice. The study found that there was a lot of optimism among dealer principals to introduce and manage the concept of enterprise development within the group. A convenience sample of dealer principals from within the group countrywide was taken as well as that of beneficiary enterprises initiatives operating countrywide as well for this study. The actual occurrence of enterprise development within the McCarthy Ltd franchised dealer network however was not encouraging, at least based on the actual reported initiatives in existence. The study found that there was a significant gap between the requirements of start-up or early stage enterprises and requirements of maturing to mature businesses. It also indicated that dealer principals were not necessaril y always adequately equipped to deal with the requirements of beneficiary enterprise requirements and hence the low occurrence or lack of introduction of enterprise development initiatives on a much wider scale. / Dissertation (MBA)--University of Pretoria, 2010. / Gordon Institute of Business Science (GIBS) / unrestricted

archives@tulane.edu / Despite great progress in the treatment viral illnesses, epidemics of emerging infectious diseases often have no specific treatments, leaving most patients to be treated with only supportive care. Broad-spectrum antiviral drugs could help ease this burden especially in situations where diagnostics are limited. Recently, many antiviral peptides have been discovered to inhibit a wide array of viruses using the Wimley-White interfacial hydrophobicity scale to predict inhibitory peptides, some of which were found to possess broad-spectrum activity. These broad-spectrum peptides share some common characteristics: they are moderately hydrophobic and have a propensity to disrupt membranes. We hypothesize that there are general molecular characteristics that these peptides possess, such as a propensity for membrane interaction, that drive broad-spectrum antiviral activity, which we can utilize for the design of novel potent antiviral peptides. To test this hypothesis, we first selected membrane-active peptides with no previously known antiviral activity. We screened these peptides against multiple diverse viruses and found that a majority possess antiviral activity with little cytotoxicity. We next explored the mechanism of action and found that peptides bind virus and cause rapid aggregation. We then used this information to guide the design of novel gain-of-function antiviral peptides. We sequentially designed peptides to test specific hypotheses about sequence motifs that may alter antiviral activity and/or cytotoxicity. Through our screenings we uncovered sequence motifs that led to greater antiviral activity, lower cytotoxicity, and potent broad-spectrum activity. More optimization is needed to turn these peptides into viable drug candidates, but we believe our findings identified important design aspects of antiviral peptides that could lead to the creation of potent broad-spectrum antiviral therapeutics. / 1 / Andrew Hoffmann