abstract: Urbanization provides an excellent opportunity to examine the effects of human-induced rapid environmental change (HIREC) on natural ecosystems. Certain species can dominate in urban habitats at the expense of biodiversity. Phenotypic plasticity may be the mechanism by which these 'urban exploiters' flourish in urban areas. Color displays and condition-dependent phenotypes are known to be highly plastic. However, conspicuous color displays are perplexing in that they can be costly to produce and may increase detection by enemies. The Western black widow spider () is a superabundant pest species that forms dense aggregations throughout metropolitan Phoenix, Arizona, USA. Adult female display a red hourglass on their abdomen, which is speculated to function as a conspicuous warning signal to enemies. Here, I performed field studies to identify how widow morphology and hourglass color differ between urban and desert subpopulations. I also conducted laboratory experiments to examine the dietary sensitivity of hourglass coloration and to identify its functional role in the contexts of agonism, mating, and predator defense. My field data reveal significant spatial variation across urban and desert subpopulations in ecology and color. Furthermore, hourglass coloration was significantly influenced by environmental factors unique to urban habitats. Desert spiders were found to be smaller and less colorful than urban spiders. Throughout, I observed a positive correlation between body condition and hourglass size. Laboratory diet manipulations empirically confirm the condition-dependence of hourglass size. Additionally, widows with extreme body conditions exhibited condition-dependent coloration. However, hourglass obstruction and enlargement did not produce any effects on the outcome of agonistic encounters, male courtship, or predator deterrence. This work offers important insights into the effects of urbanization on the ecology and coloration of a superabundant pest species. While the function of the hourglass remains undetermined, my findings characterize the black widow's hourglass as extremely plastic. Plastic responses to novel environmental conditions can modify the targets of natural selection and subsequently influence evolutionary outcomes. Therefore, assuming a heritable component to this plasticity, the response of hourglass plasticity to the abrupt environmental changes in urban habitats may result in the rapid evolution of this phenotype. / Dissertation/Thesis / M.S. Biology 2014

No description available.

This study is an investigation into the use of an African indigenous narrative game, Masekitlana, which I used as a therapeutic medium for four children, aged eight to 12 years. The participants are of Zulu origin and culture and were affected and orphaned as a result of HIV/AIDS. The game involved the participants in activities, such as hitting stones together or arranging them at will, that they felt familiar with and that enabled freer verbal expression from them. I employed a single-system research design that consisted of mixed methods approaches in the form of a qualitative thematic analysis and a quantitative graphic presentation of the results. The research design was a time series design that involved using, at four different times along the process of therapy, the measure of the Roberts-2 test (ethnic version). Therapy consisted of three sessions of standard of care therapy (therapy that was routinely being used in the psychology clinic) and three intervention therapy sessions of Masekitlana. I found the mixed-methods approach to be a practice-friendly form of research as it helped to describe the concerns of the participants in depth and enabled a concrete, quantitative conclusion about the efficacy of Masekitlana as an intervention. Syncretism of both approaches meant that qualitative data helped to clarify and confirm the findings of quantitative data and vice versa. Qualitative analysis showed how Masekitlana helped participants to express their traditional African beliefs, such as belief in the guidance of their ancestors, in the influence of bewitchment in their lives, and in the animation of the natural world. Thematic analysis also revealed the anger that participants felt resulting from the sense of disempowerment they experienced in Children’s Homes and from their separation from their biological families, and their need to sublimate this anger into future careers in the police force or alternatively to resort to crime. Thematic analysis also revealed the strategies employed by participants for coping with peer conflict in the Children’s Homes, and the challenges they face with schooling difficulties. Quantitative analysis revealed how participants progressed to complex forms of adaptive functioning and explanation of situations in their lives as a result of Masekitlana therapy. Recommendations arising out of this study are that psychologists strive to use forms of therapy that are familiar to the cultural backgrounds of indigenous children, and that training psychologists learn about the cultural beliefs of their patients and be exposed to the rituals used in traditional environments in order to understand indigenous clients. Psychologists should also be aware of the fact that, with the effects of television on children, and with present globalization and ease of international travel, children of African origin and culture are a mixture of traditional African and modern Western values. Therefore an integration of Western and indigenous forms of psychology might be considered. / Thesis (PhD)--University of Pretoria, 2012. / Educational Psychology / unrestricted

研究目的：本研究旨在探究高功能自閉症類群障礙（High-Functioning Autism Spectrum Disorder, HFASD）兒童基本的運動知覺、動物生物性運動知覺、與人類生物性運動知覺之偏好注視表現與注意力時間歷程，逐步澄清HFASD兒童的生物性運動知覺表現與社會缺損的關聯性。此外，針對自閉症類群障礙的異質性，進一步探討HFASD兒童具智能優異特質者之生物性運動知覺表現。 研究方法：本研究共招募50名7至10歲之HFASD兒童與25名配對生理年齡與智力之TD兒童。本研究採偏好注視作業，以光點呈現三種運動刺激對比的視覺配對情境：（1）基本運動知覺：物體運動配對散亂運動；（2）動物生物性運動知覺：動物運動配對物體運動；（3）人類生物性運動知覺：人類運動配對動物運動。透過眼動追蹤技術測量受試兒童觀看各運動刺激之凝視時間比例與時間歷程之凝視可能性。研究亦涵蓋智力、症狀嚴重度、及適應行為評估。 研究結果：基本運動知覺方面，TD兒童與HFASD 兒童皆對散亂運動具偏好反應。生物性運動知覺方面，整體來說，TD與HFASD兒童皆較偏好動物與人類運動。時間歷程分析顯示，HFASD與TD兒童在相同的時間窗格對動物與人類運動產生偏好興趣。此外，在動物生物性運動知覺中，於時間歷程早期階段，HFASD兒童偏好動物運動之程度低於TD兒童，且偏好動物運動的程度與社會溝通缺損具相關性，於晚期階段，兩組偏好動物運動的程度無顯著差異。在人類生物性運動知覺中，於時間歷程早期階段，HFASD兒童偏好人類運動的程度與TD兒童相當，隨時間遞增，TD兒童維持對人類運動的偏好興趣，然而，HFASD兒童對人類運動的偏好興趣則逐步遞減，至晚期階段，HFASD兒童偏好人類運動的程度顯著低於TD兒童，且與自閉症狀具相關性。考量本研究HFASD兒童樣本之異質性，結果指出智能優異的HFASD兒童對動物生物性運動的偏好程度與TD兒童相當，但在人類生物性運動知覺中，智能優異組與非智能優異組皆隨時間遞增對人類運動的偏好興趣則逐步遞減。 總結：研究結果指出，HFASD兒童對生物性運動的偏好興趣及產生偏好的速度與TD兒童無明顯差異。但HFASD兒童對人類生物性運動偏好興趣的持續度較TD兒童低落，且不因認知優勢具補償作用。整體而言，顯示HFASD兒童的生物性運動知覺表現型態在反映其社會缺損上具有參考價值。本研究也進一步探討臨床應用、研究限制與未來的研究方向。 / Purposes: This study investigated the preferential attention and attentional processing on the basic motion perception, animal biological motion perception, and human biological motion perception in children with High-Functioning Autism Spectrum Disorder (HFASD). It aimed to explore the processing of biological motion perception in children with HFASD and the association to social deficit. Moreover, concerning the heterogeneity within ASD, the study examined the biological motion perception in intellectually gifted children within HFASD. Method: Fifty children aged 7 to 10 years with HFASD and twenty-five children with typically development（TD）matched on age and IQ were recruited. The current study utilized preferential looking paradigm and motion point-light displays, demonstrating three visual comparison: (1) basic motion perception: object motion paired with scrambled motion; (2) animal biological motion perception: animal motion paired with object motion; (3) human biological motion: human motion paired with animal motion. Eye-tracking techniques were applied to measure proportion of dwell time and time course of fixation probability on each motion stimuli. Cognitive function, symptom severity, and adaptive function were also measured. Result: In basic motion perception, children with TD and HFASD preferentially attend toward scrambled motion. In biological motion perception, generally, children with TD and HFASD preferentially attend toward animal motion and human motion. Time-course analysis revealed that children with TD and HFASD attended toward animal motion and human motion at the same time window. Moreover, in animal biological motion perception, children with HFASD showed lower preferential interest in animal motion than children with TD at the early stage of time course, and there were no significnant difference between groups at the late stage of time course. The results also found that the level of preference for animal motion was associated with the severity of social communication. In human biological motion perception, children with TD and HFASD showed similar level of preferential interest in human motion at the early stage of time course; afterthat, children with TD matained preferential interest in human motion across time, but children with HFASD reduced preferential interest in human motion across time. At the late stage of time course, children with HFASD showed significantly lower level preferential interest in human motion than children with TD, and it was associated to symptom severity. Concerning the heterogeneity within the study sample of HFASD, results indicated that there was no difference on the level of preferential interest in animal motion between intellectually gifted HFASD (IG-HFASD) and TD group; however, in human biological motion perception, IG-HFASD and nonIG-HFASD group reduced preferential interest in human motion across time course compared to TD group. Conclusion: Findings suggested that children with HFASD exhibit the equivalent preferential interest and speed of attending to biological motion as did TD children. However, children with HFASD reduced referential interest in human biological motion across time course compared to TD children, and not influenced by the intellectually gifted advantage with compensation. The results implicated that biological motion perception may play an important role to understanding the social deficit in children with ASD. Theoretical and clinical implications of the study were discussed.