Eight groups of approximately ten college students each who smoked at least one package of cigarettes a day were observed for two 30 -minute sessions a week for a 5-week period. During the treatment session, students either made commitments not to smoke during post-treatment sessions, made commitments along with reasons, only gave reasons why they should not smoke, or made no statements.

This investigation concerned teaching specific parent skills and improving parent attitudes. The purpose of this study was to compare the effectiveness of three techniques and combinations of techniques in teaching specific parent skills and improving parent attitudes. The techniques considered were microtraining, verbal reinforcement via immediate feedback, and traditional parent training.

Signal Transduction is mediated by protein complexes whose spatial- and temporal-distribution, composition and function within cells are often regulated by different post-translational modifications (PTM). As PTMs add or subtract a specific mass difference to a protein, mass spectrometry becomes very amenable for modification analysis. These modifications have conventionally been monitored by fragmenting the modified protein or peptide by collision induced dissociation (CID) within the mass spectrometer, and then screening for the characteristic neutral fragment or fragment ion (marker ion), which is particular to the modification in question. Unfortunately, there are two major issues with respect to the traditional mass spectrometric analysis of PTMs: (1) as there are over 300 known types of modifications, the characteristic fragmentation of only a fraction of these modifications has been studied and (2) the traditional mass spectrometric approaches can only monitor these modifications sequentially, and thus comprehensive modification analysis would be unfeasible considering the breadth of PTMs. The following work aims to address these issues by (1) analyzing PTMs that have never been characterized mass spectrometrically and (2) developing a multiplexed technique for comprehensive PTM monitoring by simultaneously screening for all known characteristic fragments. With respect to the first issue, the characteristic fragmentation of lipid modifications and HNO-induced modifications was investigated. The most prevalent indicator(s) of the modification within the mass spectra are as follows: fragmentation of N-terminal myristoylated peptides produced marker ions at 240 and 268 Th, fragmentation of cysteine farnesylated peptides produced a marker ion at 205 Th and a neutral fragment of 204 Da, and fragmentation of cysteine palmitoylated peptides produced a neutral fragment of 272 Th. For HNO-induced modifications, fragmentation of the sulfinamide- and sulfinic acid-modified peptides produced a neutral fragment of 65 Da and 66 Da, respectively. With respect to the second issue, a multiplexed technique for monitoring modifications that fragment as neutral losses, termed Multiple Neutral Loss Monitoring (MNM), has been developed, successfully validated, and then shown to be the most sensitive approach for PTM analysis. MNM, combined with a second multiplexed approach, targeted Multiple Precursor Ion Monitoring, has been used to provide a comprehensive PTM analysis. / Science, Faculty of / Chemistry, Department of / Graduate

A currently burgeoning area of research has demonstrated that interpretation biases play a causal role in the onset of anxiety, and by training interpretation biases towards benign interpretations of ambiguity, experimental paradigms can be used to decrease levels of clinical and trait anxiety in both adults and children. Drawing on this well-documented experimental literature, and recently growing treatment literature, training anxious mothers to more benign interpretations of ambiguity in their children\'s environment may not only lessen their own anxious cognitions, but also reduce the anxious cognitions they transmit to their children. The primary objective of the current study was to determine whether a uniquely interpersonal interpretation modification paradigm (IMP) could alter the transmission of an anxious information processing style from clinically anxious mothers to their children. Results suggest that the IMP, compared to a control condition, resulted in fewer child-referent anxious cognitions in mothers and warmer maternal behavior directed to children during preparation for an anxiety-provoking speech task; however, child self-referent anxious cognitions, child behavior, and child physiological arousal during the speech task were not differentially affected. Mother and child general interpretation biases decreased over time in both groups. The current study is discussed as a pivotal step towards assessing the feasibility of modifying anxious mothers\' interpretation biases concerning their children in real-life clinical settings. / Ph. D.

Bananas and plantains (Musa spp.) are cultivated commercially as a dessert fruit and by small-scale farmers as a staple food crop in many countries of the world. Sustainable production, however, is threatened by a number of diseases and pests such as Fusarium wilt (Fusarium oxysporum f.sp. cubense), black Sigatoka (Mycosphaerella fijiensis), the banana weevil (Cosmopolitus sordidus) and the burrowing nematode (Radopholus similis). Many diseases and pests of banana cannot be managed by conventional control methods, and replacement cultivars are often not acceptable to local industries. Resistance can be introduced into banana by means of conventional and unconventional improvement methods. Conventional breeding programs have many limitations, due to sterility of cultivated bananas, long growth cycles, low seed set and hybrids that are often not accepted by consumers. Unconventional improvement for enhanced resistance involves methods such as in vitro mutagenesis, protoplast culture, and genetic modification. During genetic modification, foreign genes are introduced into banana by means of Agrobacterium-mediated transformation or by particle bombardment. One of the most powerful means to reduce the impact of pests and diseases is the use of somatic embryogenesis for unconventional plant improvement and the propagation of disease-free plants. In this thesis, immature male flowers of Grande Naine (Musa acuminata, Cavendish subgroup, AAA) were isolated and incubated on MA1 medium to form somatic embryos with ideal callus. When ideal callus was transferred to liquid MA2 medium, a heterogeneous cell suspension was formed. Non-embryogenic aggregates were removed to ensure a cell suspension constituted of small embryogenic clusters only. Somatic embryos were obtained from the cell suspension after plating the embryogenic clusters on solid MA3 medium. These somatic embryos were transferred to MA4 medium for germination, and to P6 medium to develop into in vitro plantlets. Embryogenic cell suspension can be used for genetic engineering of disease and pest resistant plants, in vitro mutagenesis, germplasm conservation and protoplast culture. An Agrobacterium-mediated transformation system was established for the improvement of Cavendish banana cultivars, the only bananas produced for the fresh fruit market in South Africa. Embryogenic cell suspensions from the cultivar Grande Naine were co-cultivated with Agrobacterium strains harbouring the plasmids pCambia1305.1, pART-TEST7 and pKYΩOCI. Antibiotic-resistant embryos derived from transgenic cell suspensions developed into banana plantlets 12 weeks after cultivation on MA4 medium. In total, 145 putative transgenic plants were produced. Molecular analysis revealed that the Gus gene was integrated into the genome of transformed plants, and a histochemical GUS assay showed that the Gus gene was expressed in putative transgenic plants. In future, southern blot assays will be performed to determine copy numbers of the transgenes, and the putative transgenic plants containing the OcI gene tested in the greenhouse and the field for resistance to the banana weevil and the burrowing nematode. The successful transformation of Grande Naine reported in this work will contribute significantly towards improving Cavendish bananas in South Africa, and offers the opportunity to modify banana and plantain varieties cultivated in Africa for enhanced disease and pest resistance. A highly discriminative fingerprinting technique, called amplified fragment length polymorphisms (AFLPs), was used to differentiate between closely related species within the Cavendish banana subgroup. AFLP profiles of eight banana varieties, cultivars and hybrids were generated on a Licor analyser using seven different primer combinations. Results showed that the banana plants were subdivided in clades according to their genomic composition. More importantly, the AFLP technique was able to separate the different cultivars within the Cavendish subgroup. Hopefully this technique could eventually be applied to accurately detect somaclonal variants in banana due to micropropagation and genetic modification. / Dissertation (MSc)--University of Pretoria, 2006. / Microbiology and Plant Pathology / unrestricted

Behavioral studies have shown that youths in various settings can function effectively as behavior change agents. This study used five 15 to 18 year old male youths in a closed institutional setting as behavior change agents for five male Youth Counselors. Youths specified staff behaviors they wanted to change, collected frequency data on each specified staff behavior, and suggested and implemented treatments to change staff behavior. A multiple baseline design across staff members was used to demonstrate the effects of youths' interventions on staff behaviors. Staff increased their frequency of positive verbal comments and decreased their frequency of negative verbal comments and threats .. _regarding loss of privileges following a one-time feedback -from youths regarding staff's baseline frequency_of responses. Two staff members received a second treatment consisting of verbal feedback and praise immediately following each data collection session. This treatment was too short to have an effect on positive and negative verbal comments, but ·appeared to decrease staff's frequency of threats to a near zero rate. Follow-up revealed that frequency of responses did not return to the baseline rate in most cases. Consistent with past studies that have used youths as behavioral change agents, the present findings demonstrate that 11 delinquent" youths can be (a) accurate and reliable data collectors, and (b) effective behavior change agents for staff.

Casuarina equisetifolia L. is a noxious plant species known to be invasive in the West Indies. Not much is known about its impact on its host environment. This study’s objective was to quantitatively compare physical and chemical soil differences between sites dominated by and devoid of Casuarinas. This study also conducted growth chamber experiments to determine potential for allelopathy. It was demonstrated that sites dominated by Casuarinas differed significantly in K, P, organic matter, and leaf litter depth. Application of Casuarinas leachate showed reduction in germination of radish and bean seeds by at least 32% and 70%, respectively. Once germinated no growth suppression of seedlings were observed with applications of Casuarinas leachate. Investigation with liquid chromatography mass spectrometry (LC-MS) revealed the potential presence of the allelochemical chalepin. This research demonstrates that Casuarinas have the potential to modify their host environment and therefore perpetuate their existence as a noxious invasive species.

<p> During the spring and summer months of 1967, measurements of the temperature and moisture regimes under a control, and lamp black, white talc, and straw mulch surface treatments, on a fine sandy loam, and a sandy clay loam, were undertaken. The sites were the McMaster University campus, and the Arboretum of the Royal Botanical Gardens in Hamilton, Ontario.</p> <p> A description of the experimental procedures is presented in Chapter II. Chapter III discusses the regimes of soil temperature and moisture - content; and also the effects of clear and cloudy skies, and rain on soil temperatures.</p> / Thesis / Master of Arts (MA)

No description available.

No description available.