The ammonolysis of esters in liquid ammonia

The rates of ammonolysis of alkyl benzoate and phenylacetate esters in liquid ammonia increase with the acidity of the leaving group alcohol and show relatively large Brønsted βlg values of −1.18 and −1.34, respectively, when plotted against the aqueous pKa of the alcohol. The Brønsted βlg obtained using the pKa of the leaving group alcohol in liquid ammonia is significantly reduced to ~ −0.7, which indicates that the rate-limiting step involves a reaction of the tetrahedral intermediate with little C–OR bond fission in the transition state. The solvolysis reaction is subject to significant catalysis by ammonium ion, which, surprisingly, generates a similar Brønsted βlg indicating little interaction between the ammonium ion and the leaving group. It is concluded that the rate-limiting step for the ammonium-ion-catalysed solvolysis of alkyl esters in liquid ammonia is the diffusion-controlled protonation of the zwitterionic tetrahedral intermediate T+- to give T+, which is rapidly deprotonated to give T0 which is compatible with the rate-limiting step for the uncatalysed reaction being the formation of the neutral T0 by a ‘proton switc

Foreign Governmental Control of Multinational Corporations Marketing in the United States

It seems appropriate to begin this discussion of foreign governmental control of multinational corporations marketing in the United States by briefly reviewing the structure of the petroleum industry and the historical events leading to the Arab oil embargo

Caritas and Ren: a comparative study of Thomas Aquinas and Zhu Xi in the contexts of their traditions

The thesis is a comparison of Chinese and Western, Confucian and Christian, ideas and values. Its central focus is on caritas as the primary Christian virtue, and ren (benevolence) as the primary Confucian virtue. The comparison deals eventually with the way in which these virtues are read by Aquinas and xhu Xi, and situated within their philosophies as a whole. Aquinas and Zhu Xi are in read in relation to their traditions, in order to identify the tensions and presuppositions that are incorporated in their work. Attention is also given to the problems of reading Historical texts, and texts from different cultural traditions, both in terms of the hermeneutic issues at work in such reading, and the possible significance that such reading might have for contemporary culture

Investigating the effects of antioxidant vitamins on the immunocompetence of domestic turkeys (Meleagris gallopavo) infected with coccidian parasites

Vitamins are organic compounds essential for healthy metabolism and growth. Additionally, some vitamins also function as antioxidants. In particular, the antioxidant vitamins A (p-carotene) and E (a-tocopherol) are known to enhance the immune response of many animals as well as humans. However, there is relatively little research linking these immune-enhancing effects to domestic turkeys facing parasitic infections, such as coccidiosis. Coccidiosis in birds is expensive to treat, costing the worldwide poultry industry hundreds of millions of dollars annually. Coccidia of the genus Eimeria are protozoans that parasitize poultry via the intestinal tract, causing deleterious effects to survival such as lesioning, reduced growth rate, and mortality. Twenty-two broad breasted white turkey poults {Meleagris gallopovo) were inoculated with 12 000 coccidian oocysts by mouth. The diet for one-half of the subjects was supplemented with high doses of vitamins A and E. Daily fecal samples from each subject were collected starting 72 hours after inoculation for six days. Feces were examined for oocyst concentration per gram of feces using a microscope. The mass of the spleen, testes, bursa of Fabricius, change in body condition, and erythrocyte and white blood cell fractions were also measured for each subject. There was a significant interaction of treatment and sex in the white blood cell fraction (ANOVA, F = 4.716, p - 0.05). Supplemented females showed a significantly higher white blood cell fraction (t-test, t = -3.278, ni = 3, n2 = 8, p = 0.001). Based on these findings, antioxidants may work in conjunction with estrogens to reduce oxidative stress in turkeys that can lead to an enhanced immune response. Future studies should focus on using antioxidants in conjunction with other proven methods to elicit a compound increase in turkey immune function