The hippocampus and non-hippocampal long-term memory systems each have the capacity to learn and express contextual fear memory. How these systems interact during learning and remembering revolves around hippocampal mediated interference, where the hippocampus dominates for both the acquisition and expression of long-term memory. Hippocampal interference during learning can be overcome by modifying learning parameters such that learning is distributed across multiple independent sessions. The standard view of the role of the hippocampus in long-term memory retrieval is that it is temporally limited, where recently acquired memory is dependent on hippocampal function though as a memory ages, dependency is transferred to other memory systems by a process called systems consolidation. Distributed training demonstrates that learning parameters create a memory that is resistant to hippocampal damage. We find little evidence to support temporally based systems consolidation, and present data that supports the view that if the hippocampus is initially involved in learning a memory, it will always be necessary for accurate retrieval of that memory. A critical assessment of the rat literature revealed that initial memory strength, and/or lesion techniques might be responsible for the few studies that report temporally graded retrograde amnesia using contextual fear conditioning. Our experiments designed to directly test these possibilities resulted in flat gradients, providing further evidence that the hippocampus plays a permanent role in long-term memory retrieval. We propose and assess alternatives to the standard model and conclude that a dual store model is most parsimonious within the presented experiments and related literature. Interactions of the hippocampus and non-hippocampal systems take place at the time of learning and remembering, and are persistent over time. / xvi, 161 leaves : ill. (some col.) ; 29 cm

This thesis examines both behavioral and anatomical effects of prenatal exposure of Valproic Acid (VPA) on Long Evans rats. Tactile stimulation (TS) is then used to investigate its’ effect on remediating any abnormalities VPA may produce. Several behavioral tests were done to assess the behavioral effects of VPA and TS. It was found that VPA had an effect of many of the tasks, whereas, TS had almost none with the exception of an effect on females in the elevated plus maze. However, anatomical data showed that TS had a profound effect on neuronal branch order, cell complexity, and spine density in pyramidal neurons in the medial prefrontal cortex, the orbitofrontal cortex and the amygdala. Where VPA decreased the above in all of these areas, TS increased neuronal complexity in the aforementioned structures. This study demonstrates that prenatal exposure to VPA is a viable model of autism in rats and that TS has significant anatomical effects in these animals as well as in control animals / xi, 98 leaves; 29 cm

The usefulness of frontal lobe (FL) dysfunction as a conceptual model for Attention Deficit Hyperactivity Disorder (ADHD) was investigated. Twenty-four ADHD and 24 normal control (NC) children were tested using tasks sensitive to FL deficits in motor control and problem solving skills and memory tasks sensitive to temporal lobe (TL) dysfunction. ADHD children differed significantly from NCs on measures of FL function, but not on tests of TL functions. Wherever norms were available for normal children on the same FL tests, ADHD subjects performed like 6 to 7 year olds, in spite of their mean age of 10 years and minimum age of 8 years. The differential performance of ADHD children on tasks sensitive to FL and TL damage supports the conceptualization of ADHD deficits as analogous to FL dysfunction and implies that deficits are not explained by reference to generalized impairment.

The purpose of this study was to separate acute and chronic effects of moderate exercise on the immune system by analyzing three sets of experimental and control groups; (1) 72 hours, (2) 1 week, (3) 2 weeks post exercise. Mice swam 5 days per week for 3 weeks accumulating a total of 125, 225, and 225 minutes of exercise in weeks 1, 2, and 3, respectively. Moderate swimming exercise did not result in a significant increase in SDH levels (p > 0.05). There was no change in tissue cell responses as measured by mitogen responsiveness, nor in splenic and thymic cell counts in response to the training regimen at any time point (p ≥ 0.05). Total, CD4, CD8, and T cell counts in the lymph nodes were significantly suppressed at 72 hours and 2 weeks post exercise (p ≤ 0.05). It appears that chronic exercise resulted in an increased trafficking of lymphatic cells, which could be interpreted as a sign of heightened immune reactivity.

No description available.

Regular participation in sports is a common practice among the general population. For cardiovascular fitness, the frequency, duration, intensity and mode of the activity must be appropriate for the individual to benefit from the activity. The benefits for cardiovascular fitness are questionable in sports involving high intensity intermittent exercise of short duration. In the past, the procedures for determination of the heart rate and the time-motion characteristics of an activity were cumbersome and time consuming, thus making application to sports an inconvenience. The purpose of this project was to develop a computer based system for matching heart rate data with time-motion characteristics. The system was tested using ice hockey and squash. Subjects were observed during activity. The heart rate data during the activity were collected using a Polar Vantage XL Heart Rate monitor set to record heart rate values in 5-second intervals. The duration and type of activity were entered in the computer in real time using a coding system. Program combined the time-motion analysis with the heart rates that were downloaded from the Polar heart rate monitor. The results were summarized as follows: (1) total time at each intensity level, (2) mean duration at each intensity level, and (3) mean heart rate at each intensity level. Output from the computer program was similar to manual calculations.

The purpose of this study was to determine whether team and individual, male and female athletes, have different potentials for burnout, and to examine if these populations use different coping strategies. / One-hundred and sixteen male, and 57 female varsity and elite judo athletes completed the EABI and COPE inventories and a personal background form. T-tests confirmed individual sport athletes to be more prone to burnout than team sport athletes, high level athletes more prone to burnout than those at lower competitive levels and emotional social support as a coping strategy more prevalent among team than individual sport athletes. No differences were found between males and females in proneness to burnout or means of coping. The length of sport involvement was not found related to proneness to burnout. The importance of sport in athletes' lives gave mixed results when related to burnout. / These results, while confirming some earlier findings suggest also the need for further study.

This study identified gender-related differences in post-exercise peripheral blood flow and body temperature in neutral environment (21ºC). The subjects were 11 male (22 +/- 4 years) and 14 pre-ovulatory female (23 +/- 3 years) recreational runners VO2max: 62 +/- 5 mL/kg &bull; min for men and 55 +/- 5 mL/kg &bull; min for women). Forearm blood flow rectal (Trec) and forearm skin temperatures (Tsk), and forearm vascular resistance (mean arterial pressure/forearm blood flow) were measured pre-exercise (pre), immediately after (t = 0), and every 15 minutes up to 105 minutes (t = 105) post-exercise (45-minute run at 75% of VO2max). ANOVA revealed main gender effects for Trec, Tsk, and forearm blood flow (men > women) as well as for forearm vascular resistance (women > men). Compared to pre-exercise, Trec at t = 0 showed a similar increase in men (1.3ºC) and women (1.2ºC). Trec decreased thereafter to reach pre-exercise level after 25 minutes in men. In women, Trec kept decreasing to reach a lower than pre-exercise level after 60 minutes (p < 0.05). Tsk was similar at pre and t = 0 for both genders. In contrast, Tsk was lower in women than men (29.0 +/- 1.3 versus 30.7 +/- 1.5ºC) at t = 105 (p < 0.05). Forearm vascular resistance was similar in men and women pre-exercise and decreased by about 50% in both groups at t = 0. Between t = 30 and t = 105, the women increased their forearm vascular resistance up to 35% more than did the men. These observations suggest the existence of gender-related differences in thermoregulatory and cutaneous blood flow responses during recovery from submaximal exercise.

<p>The incidence of cardiovascular diseases, including hypertension, is on the increase worldwide. Medicinal plants played an important role in the treatment of hypertension for centuries. Very few scientific studies have, however, been done to validate the use of these phytotherapies. O africana is on of the many phytotherapies that has been use indigenously for years to treat hypertension. The objectives of this study were to determine the most effective does of O africana aqueous extract which will reduce blood pressure / to determine whether chronic administration of O africana can be used to prevent and treat hypertension / to determine whether O africana exert its effects by modulation of the renin-angiotensin system.</p>

<p>The study aims to understand the challenges facing the Itinerant Learning Support Educators in an Inclusive Education framework. At the onset of the study there were very limited research studies and literature available on the challenges facing Itinerant Learning Support Educators hence literature in the study drew on the development and history of Special Education towards a global shift with regard to Inclusive Education policy development. As such the literature was utilized to understand how global phenomena and policies in developed countries impact on local policy transformation and contexts. The study followed a qualitative research approach to explore the challenges facing Itinerant Learning Support Educators in performing their functions. To gain an in depth understanding of their perceptions a case study method was followed and data collection techniques included focus group interviews. The sample in this study comprised of 14 Itinerant Learning Support Educators. The data was analyzed using a thematic approach. The findings of this study highlighted that despite a shift towards Inclusive Education in South Africa, Itinerant Learning Support Educators found themselves challenged by a range of contextual issues that impacted on the effective delivery of inclusive principles and practices. The study recommends that the Department of Education should take cognisance of these challenges, review the job description of Itinerant Learning Support Educators and put clear guidelines and support structures in place to support them in functioning optimally within an Inclusive Education paradigm.</p>