Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1990. / Vita. Abstract. Includes bibliographical references (leaves 67-73). Also available via the Internet.

Thesis PlanB (M.S.)--University of Wisconsin--Stout, 2009. / Includes bibliographical references.

Thesis, PlanB (M.S.)--University of Wisconsin--Stout, 1999. / Includes bibliographical references.

Saarbrücken, Univ., Diss., 2000.

University, Diss., 2000--Saarbrücken.

Fish naturally experience fluctuating levels of O2 and CO2 in their environment. To cope with the deleterious effects of lowered O2 (hypoxia) or elevated CO2 (hypercapnia), fish exhibit an array of cardiorespiratory adjustments aimed at preserving homeostasis. One of the most significant of these responses is reflex hyperventilation. In zebrafish (Danio rerio), hyperventilation during hypoxia or hypercapnia is thought to be initiated by the activation of chemoreceptor cells, termed neuroepithelial cells (NECs) which detect changes in ambient levels of O2 or CO2. The NECs of larval zebrafish are found throughout the integument and recent studies have shown that these NECs likely mediate the ventilatory responses to hypoxia and the cardiac responses to hypercapnia. However, no study has yet examined the ventilatory response of larval zebrafish to hypercapnia and regardless of developmental stage, the signalling pathways involved in CO2 sensing remain unclear. In the mouse, a background potassium channel (TASK-2) was shown to contribute to the sensitivity of chemoreceptor cells to CO2. Zebrafish have two specific TASK-2 channel paralogs encoded by kcnk5a and kcnk5b. The purpose of this thesis was to determine whether TASK-2 channels are expressed in NECs of larval zebrafish and whether they are involved in CO2 sensing. Immunohistochemical approaches were used to visualize TASK-2 protein (encoded by kcnk5a) within NECs of larvae and adult gill. TASK-2 protein was observed on NECs in both larvae and adult gill. Exposure of larvae to hypercapnia caused an increase in cardiac and breathing frequencies; these responses were blunted in fish experiencing either TASK-2 and/or TASK-2b knockdown. The results of these experiments suggest that TASK-2 has a role in activating NECs thus eliciting cardiorespiratory responses, when larvae are exposed to hypercapnia.

The exact properties of the interaction between emotional drives and other psychological phenomena is still a vastly unexplored field. The purpose of this paper will be to examine further the effects of one of these emotional drives, that of fear, on task performance, and to explore some of the theoretical conceptualizations already put forth regarding this interaction.

Software maintainability is one of the most crucial quality attributes of a software product. Software engineering researchers and practitioners have devoted considerable effort to developing “good design” methods, rules and principles to improve software maintainability. But before we can validate the effectiveness of these methods, we first need an approach to measure software maintainability. The existing maintainability measures usually have limited scope and accuracy since they either isolate the software from its environment and focus only on the technical properties of the software, or measure a confounding effect of various factors involved in the maintenance process. Furthermore, these measures are often defined and collected on a coarse-grained level and provide no insight into what makes software difficult to change. This research addresses the problems associated with software maintainability measurement by adapting the concepts of task complexity from the human behavior domain to the software engineering domain. This dissertation involves developing and validating a measurement model for measuring the maintainability of software, to provide a better understanding of the difficulty in modifying software and the effect of software design methods on software maintainability. A measurement protocol and a tool have been developed to support the application of the measurement method.

The purpose of this study was to determine if task type, task complexity, and search mechanism would have a significant affect on task performance. The problem motivating this study is the potential for systems online help designers to construct systems that can improve the performance of computer users when they need help.

For decades, researchers have seen employee empowerment as the means to achieving a more committed workforce that would deliver better outcomes. The prior conceptual and descriptive research focused on structural empowerment, or workplace mechanisms for generating empowerment, and psychological empowerment, the felt empowerment. Responding to calls for intervention studies, this research experimentally tests the effects of structural empowerment changes, through different degrees of decision-making authority and access to customer-relationship information, on psychological empowerment and subsequent work-related outcomes. Using a virtual contact center simulation, crowdsourced workers responded to customer requests. Greater decision authority and access to customer-relationship information resulted in higher levels of psychological empowerment which in turn resulted in task satisfaction and task attractiveness outcomes among the crowdsourced customer service workers.