Short-term mating mechanisms should be activated only under conditions in which, ancestrally, the benefits were recurrently greater and the costs were recurrently lower than those of other potential mating strategies. The purpose of this dissertation was twofold: 1) to identify benefits and costs of short-term mating to men and women and to rank them based on magnitude, 2) and to identify how sex-specific adaptive individual differences previously known to affect mating success shift perceptions of the magnitude of, and likelihood of receiving, potential benefits and costs. To identify and rank potential benefits and costs, participants listed up to ten potential benefits and costs men and women may experience when engaging in short-term mating. A second group of participants rated the benefits and costs for how beneficial and how costly they are. A second study examined how sex-specific adaptive individual differences shift perceptions of the magnitude of, and likelihood of receiving, the nominated benefits and costs. Participants completed several questionnaires designed to measure relevant demographics and family history, personality, and previous and current mating experiences. Participants also provided their perceptions of the magnitude of each of the benefits and costs, and the perceived likelihood someone could receive each outcome. Results indicated women’s perceptions did not differ as a function of their self-perceived mate value, exposure to early environmental stress, relationship status or satisfaction, but did differ as a function of their feelings of sexual regret. Similarly, men’s self-perceived mate value, relationship status and satisfaction did not influence perceptions of short-term mating, but the amount of effort currently invested into mating and feelings of sexual regret did. Overall, this dissertation contributes a novel extension of previous research on short-term mating. This is the first study to examine the costs to women, and the benefits and costs to men of short-term mating, and the first study to examine how individual differences may shift perceptions of those benefits and costs. Findings from the current set of studies provide a more thorough understanding of men’s and women’s evolved mating psychology and highlight fruitful avenues for future research. / text

Working memory and long-term memory are two types of memory associated with children’s learning and academic performance. A number of memory models have suggested there is a relationship between working memory and long-term memory; however, there is a lack of empirical research measuring this relationship using standardized assessment tools. Further, there are currently no studies measuring this relationship in children. The purpose of this study was to investigate the relationship between children’s working memory (i.e., verbal working memory, visual-spatial working memory, verbal short-term memory, visual-spatial short-term memory, and the central executive) and long-term memory, using standardized assessment tools. The Automated Working Memory Assessment was used to measure working memory and the Woodcock-Johnson Tests of Cognitive Abilities – Third Edition was used to measure long-term memory. This study utilized secondary data from a larger SSHRC funded study. Participants included 41 children between grades 1 and 8. The majority of parents who volunteered to have their children participate identified them as having a disability (e.g., speech/language difficulty; learning disability). Kendall’s tau-b revealed statistically significant correlations between four areas of working memory (i.e., verbal working memory, visual-spatial working memory, visual-spatial short-term memory, and central executive) and long-term memory. Mann-Whitney tests revealed children with higher working memory abilities differed significantly from children with lower working memory abilities on measures of long-term memory. The findings from this study may have implications for both theory and practice. The relationship observed between working memory and long-term memory appears to align with widely accepted memory models (e.g., Baddeley, 2000; Dehn, 2008). The findings also suggest interventions designed to improve children’s working memory may have the potential to enhance long-term memory abilities.

No description available.

Electric power systems are huge real time energy distribution networks where accurate short term load forecasting (STLF) plays an essential role. This thesis is an effort to comprehensively investigate new and advanced neural network (NN) architectures to perform STLF. Two hybrid and two 3-layered NN architectures are introduced. Each network is individually tested to generate weekday and weekend forecasts using data from three jurisdictions of Canada. Overall findings suggest that 3-layered cascaded NN have outperformed almost all others for weekday forecasts. For weekend forecasts 3-layered feed forward NN produced most accurate results. Recurrent and hybrid networks performed well during peak hours but due to occurrence of constant high error spikes were not able to achieve high accuracy.

The present work is an examination of the mechanisms underlying temporal processing in vision. Recent studies have shown that when observers are asked to identify two objects presented in rapid succession, identification of the first object is quite accurate, while identification of the second object is poor when it folows the first at very brief inter-target intervals (i.e. 200-500 ms). This second-target deficit is known as the attentional blink. According to bottleneck models, the attentional blink occurs because processing of the first target prevents the second target from gaining access to high-level processing. A strong prediction of this account is that if processing time for the first target is increased, the magnitude of the attentional blink should also increase. This prediction is confirmed in experiments. It is argued that these results strongly support bottleneck models as an account of the attentional blink in particular and of temporal processing more generally.

The experiments reported in the present thesis investigated the effects of lesions to the anterior nuclei of the thalamus (ATN) on the acquisition of two spatial, working memory tasks performed on the eight-arm radial maze. In the task used in Experiment 1 and 2, the animals were required to discriminate and remember all the eight arms of the maze simultaneously. Lesions of the ATN produced impairments in the acquisition of this task, but the degree of impairment depended on the amount of damage within this region. In the task used in Experiment 3, the animals were required to discriminate and remember only two arms at once. Lesions of the ATN were shown to impair its acquisition even though performance was facilitated by the addition of visual intra-arms cues. These experiments suggest that the ATN may be involved in spatial learning and in the retention of non-specific information over time.

No description available.

Submitted in partial compliance with the requirements for the Master’s Degree in Technology: Chiropractic Durban University of Technology, 2013. / Background : Chronic non-specific neck pain is a common condition that negatively affects cervical muscle functioning and activities of daily living. Combined exercise and mobilisation are currently recommended as the most effective treatment for this condition. Mobilisation, such as mobilisation of the cervical spine, provides short-term pain relief and affects neural activity, while the craniocervical flexion exercise provides immediate pain relief and activates the deep cervical flexors. The short-term effect of mobilisation and the craniocervical flexion exercise have not been compared. Objectives : This study aimed to compare mobilisation and craniocervical flexion exercise in terms of subjective and objective outcome measures at a short-term follow-up consultation for the treatment of chronic non-specific neck pain. The null-hypothesis was that the mobilisation group would not respond differently to the craniocervical flexion exercise group. Method : A group of thirty females between the ages of 20 and 35 complaining of non-specific neck pain for more than three months were randomly allocated into either the mobilisation or craniocervical flexion exercise groups. During the first two consultations, a mobilisation was administered to the mobilisation group. Whereas the craniocervical flexion exercise and a posture correcting exercise were taught to the participants of the craniocervical flexion exercise group. The Numerical Pain Rating Scale, Neck Disability Index, Neck Bournemouth Questionnaire, cervical range of motion and algometer readings were taken at each of the three consultations. The Patient Global Impression of Change Scale was administered at the last consultation one week after the first consultation. Results : Both the mobilisation and craniocervical flexion exercise groups showed significant improvements in all of the subjective outcomes. The Neck Disability Index score of the craniocervical flexion exercise group was the only subjective outcome that did not decrease enough to be considered clinically significant. The PGIC score of the mobilisation group was slightly higher than that of the craniocervical flexion exercise group. There was no statistically significant improvement in the objective outcomes of either group. All ranges of motion decreased in both groups, while pain pressure threshold improved in both groups. There was no significant difference between the results of the subjective and objective outcomes of the mobilisation and craniocervical flexion exercise groups. Conclusions and recommendations : The two interventions were found to have a similar effect in the treatment of chronic non-specific neck pain in terms of subjective and objective outcome measures. Participants of both groups indicated on the subjective scales that their conditions improved, even though objective outcomes showed no significant change. In future studies, a larger sample size should be used and the sample should be stratified for ethnicity to increase validity of the results.

The hypothesis that consumption of whey protein (WP) prior to a meal suppresses short-term food intake and reduces post-meal glycemia by insulin-dependent and -independent mechanisms in healthy young adults was explored in three studies. Study one investigated the effect of solid vs. liquid forms of WP (50 g) and sucrose (75 g) on food intake at 1 h. Whey protein, whether in solid or liquid form, suppressed food intake more than sucrose. Study two examined the effect of WP (10-40 g) consumed 30 min prior to a meal on food intake, and pre- and post-meal blood concentrations of glucose and insulin. Whey protein reduced food intake and post-meal glycemia in a dose-dependent manner without increased blood insulin concentrations. In the third study, glycemic control after WP was compared with glucose, at doses of 10 and 20 g. Both pre-meal WP and glucose consumption reduced post-meal glycemia similarly. However, WP resulted in lower pre-meal blood glucose and delayed gastric emptying, lower pre-and post-meal and overall insulin secretion and concentrations and higher GLP-1 and PYY concentrations compared with glucose. Thus, the results of this research support the hypothesis that consumption of WP prior to a meal suppresses short-term food intake and reduces post-meal glycemia by insulin-dependent and -independent mechanisms in healthy young adults.

The hypothesis that consumption of whey protein (WP) prior to a meal suppresses short-term food intake and reduces post-meal glycemia by insulin-dependent and -independent mechanisms in healthy young adults was explored in three studies. Study one investigated the effect of solid vs. liquid forms of WP (50 g) and sucrose (75 g) on food intake at 1 h. Whey protein, whether in solid or liquid form, suppressed food intake more than sucrose. Study two examined the effect of WP (10-40 g) consumed 30 min prior to a meal on food intake, and pre- and post-meal blood concentrations of glucose and insulin. Whey protein reduced food intake and post-meal glycemia in a dose-dependent manner without increased blood insulin concentrations. In the third study, glycemic control after WP was compared with glucose, at doses of 10 and 20 g. Both pre-meal WP and glucose consumption reduced post-meal glycemia similarly. However, WP resulted in lower pre-meal blood glucose and delayed gastric emptying, lower pre-and post-meal and overall insulin secretion and concentrations and higher GLP-1 and PYY concentrations compared with glucose. Thus, the results of this research support the hypothesis that consumption of WP prior to a meal suppresses short-term food intake and reduces post-meal glycemia by insulin-dependent and -independent mechanisms in healthy young adults.