It has been proposed that relapse vulnerability in previously dependent individuals results from augmentation of drug-induced reinforcement due to repeated associations between the interoceptive properties of the drug and reduction of acute withdrawal distress. To test this hypothesis, male Sprague-Dawley rats self-administered 0.05 mg/kg/inf heroin on continuous and progressive ratio (PR) schedules. During this period, they also received injections of vehicle or escalating doses of heroin. Following tests of naloxone-precipitated withdrawal (0.01 or 0.1 mg/kg, SC), as well as abstinence (4 days), and extinction training (9 sessions), they were pre-treated with vehicle or yohimbine (0.5 mg/kg, IV) and tested for resumption of heroin self-administration (0.05 mg/kg/inf) on continuous and PR schedules (Experiments 1 & 2), or tested for reinstatement in extinction conditions. Differences between vehicle- and heroin-injected rats were noted on self-administration on the continuous reinforcement schedule, but not on the PR schedule, in spite of greater signs of withdrawal precipitated by naloxone in the heroin-injected rats. More importantly, there were no group differences in resumption of heroin self-administration, and this was not altered by yohimbine. These results suggest that relapse vulnerability cannot be uniquely ascribed to the altered reinforcing action of drugs; contextual and other conditioning factors must play a role in modulating resumption of drug intake after periods abstinence.

The purpose of this study was to examine ideas about disability within social work education within three Bachelor of Social Work programs in Canada, and to identify and describe major perspectives and themes of disability. One important aspect of the study was to determine the extent to which critical disability studies perspectives were presented, explained, and discussed in the classroom within core social work theory courses, and specialized courses addressing disability. Three Bachelor of Social Work programs; St. Thomas University School of Social Work in New Brunswick, the Dalhousie School of Social Work in Nova Scotia, and the University of Manitoba Faculty of Social Work, Fort Garry Campus, were purposefully chosen for this multicase study based on a theoretical replication logic that predicted that social work education on disability within each of the schools would represent different points on a range of disability perspectives, as developed from the disability studies literature. Data collection and analysis included multiple methods, including a manifest content analysis of texts, a modified inductive analysis of transcriptions from interviews with key informants, and a critical discourse analysis of transcriptions from an audio-taped session of classes addressing disability in each case. Findings from the multicase study indicate that the original research suppositions were not supported. Based on the analysis of texts and interviews, the approach to disability followed by each Bachelor of Social Work program was found to incorporate a broad range of disability theory, particularly social pathology and critical disability perspectives. However, there was little evidence of classroom discussion and use of social work practice approaches supporting these perspectives. It was argued in the literature review to the study that anti-oppressive social work approaches, such as structural social work, were congruent with critical disability perspectives, but that there is also a need for an “infused” approach to integrating disability content into core curriculum. In conclusion, I also suggest that the Canadian Association for Social Work Education has an important leadership role to play in providing specific recommendations for disability inclusion in social work education.

Past research has shown that preference for a stimulus is correlated positively with reinforcer efficacy – more preferred stimuli tend to be more potent reinforcers. Researchers have recently examined the use of progressive ratio (PR) reinforcement schedules to evaluate preference. However, research on the concordance between preference and performance under a progressive ratio schedule is limited. Therefore, two experiments were conducted to extend this research. In Experiment 1 I compared the relative reinforcing efficacy of six stimuli obtained under a PR schedule to the mean preference hierarchy obtained through paired-stimulus preference assessments conducted before and after PR reinforcement sessions. In Experiment 2 I evaluated the PR schedule for quantifying the reinforcing value of three stimuli from Experiment 1 (i.e., one high, one medium, and one low preference stimulus). The results of Experiment 1 indicated that items that yielded higher breaking points and responses per minute were also more preferred. However, concordance between percent preference and breaking points and response rates for less preferred items was more variable. The results of Experiment 2 showed that high preference stimuli increased responding over baseline for all participants. However, low preference reinforcers also increased responding over baseline for some participants.

The purpose of this study was to examine ideas about disability within social work education within three Bachelor of Social Work programs in Canada, and to identify and describe major perspectives and themes of disability. One important aspect of the study was to determine the extent to which critical disability studies perspectives were presented, explained, and discussed in the classroom within core social work theory courses, and specialized courses addressing disability. Three Bachelor of Social Work programs; St. Thomas University School of Social Work in New Brunswick, the Dalhousie School of Social Work in Nova Scotia, and the University of Manitoba Faculty of Social Work, Fort Garry Campus, were purposefully chosen for this multicase study based on a theoretical replication logic that predicted that social work education on disability within each of the schools would represent different points on a range of disability perspectives, as developed from the disability studies literature. Data collection and analysis included multiple methods, including a manifest content analysis of texts, a modified inductive analysis of transcriptions from interviews with key informants, and a critical discourse analysis of transcriptions from an audio-taped session of classes addressing disability in each case. Findings from the multicase study indicate that the original research suppositions were not supported. Based on the analysis of texts and interviews, the approach to disability followed by each Bachelor of Social Work program was found to incorporate a broad range of disability theory, particularly social pathology and critical disability perspectives. However, there was little evidence of classroom discussion and use of social work practice approaches supporting these perspectives. It was argued in the literature review to the study that anti-oppressive social work approaches, such as structural social work, were congruent with critical disability perspectives, but that there is also a need for an “infused” approach to integrating disability content into core curriculum. In conclusion, I also suggest that the Canadian Association for Social Work Education has an important leadership role to play in providing specific recommendations for disability inclusion in social work education.

Past research has shown that preference for a stimulus is correlated positively with reinforcer efficacy – more preferred stimuli tend to be more potent reinforcers. Researchers have recently examined the use of progressive ratio (PR) reinforcement schedules to evaluate preference. However, research on the concordance between preference and performance under a progressive ratio schedule is limited. Therefore, two experiments were conducted to extend this research. In Experiment 1 I compared the relative reinforcing efficacy of six stimuli obtained under a PR schedule to the mean preference hierarchy obtained through paired-stimulus preference assessments conducted before and after PR reinforcement sessions. In Experiment 2 I evaluated the PR schedule for quantifying the reinforcing value of three stimuli from Experiment 1 (i.e., one high, one medium, and one low preference stimulus). The results of Experiment 1 indicated that items that yielded higher breaking points and responses per minute were also more preferred. However, concordance between percent preference and breaking points and response rates for less preferred items was more variable. The results of Experiment 2 showed that high preference stimuli increased responding over baseline for all participants. However, low preference reinforcers also increased responding over baseline for some participants.

This thesis is devoted to efficient VHDL design of Systolic Array Architecture for Polynomial GF(2^m) multiplication. The hardware implements the Processor Elements(PE) and Systolic Array design for Progressive Product Reduction (PPR) method proposed by Gebali and Atef. The experiment first implements a simpler irreducible polynomials GF(2^5) based on the defined algorithms for PPR in order to confirm the functionality of the design and then tries the bigger value of m for GF(2^133) and GF(2^233), recommended by NIST. The thesis is comparing the three designs based on their power consumption, Maximum Data path delay and device utilization. It also looking in to the different optimization method for the designs and recommends a design optimization based on circuit modification. / Graduate / 0544 / alinia@uvic.ca

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This research focuses on improvements and application of 1D finite elements for nonlinear dynamic analysis of reinforced concrete frames under extreme loadings. The concept of force interpolation is adopted for the element formulation and a solution scheme developed based on a total secant stiffness approach that provides good convergence characteristics. The geometrical nonlinearities including 2nd order P-Delta effects as well as catenary action are considered in the element formulation. It is shown that geometrical nonlinearities may have a significant effect on member (structure) response within extreme loading scenarios. In the analysis of structures subjected to extreme loadings, accurately modelling of the post peak response is vital and, in this respect, the objectivity of the solution with softening must be maintained. The softening of concrete under compression is taken into account, and the objectivity preserved, by adopting a nonlocal damage model for the compressive concrete. The capability of nonlocal flexibility-based formulation for capturing the post-peak response of reinforced concrete beam-columns is demonstrated by numerical examples. The 1D frame element model is extended for the modelling of 3D framed structures using a simplified torque-twist model that is developed to take account of interaction between normal and tangential forces at the section level. This simplified model can capture the variation of element torsional stiffness due to presence of axial force, bending moment and shear and is efficient and is shown to provide a reasonable degree of accuracy for the analysis of 3D reinforced concrete frames. The formulations and solution algorithms developed are tested for static and dynamic analysis of reinforced concrete framed structures with examples on impact analysis of beams, dynamic analysis of frames and progressive collapse assessment of frames taken from the literature. The verification shows that the formulation is very efficient and is capable of modelling of large scale framed structures, under extreme loads, quickly and with accuracy.

Thèse (M.Sc.)--Université Laval, 2007. / Bibliogr.: f. 180-185. Publié aussi en version électronique dans la Collection Mémoires et thèses électroniques.

Tübingen, Univ., Diss., 2004.