126 research outputs found
Germinal Epithelium Cytology during Spermatogenesis in the Alligator Snapping Turtle, Macrochelys temminckii (Reptilia: Chelydridae)
We investigated the cytology of the seminiferous epithelia of the Alligator Snapping Turtle (Macrochelys temminckii). Spermatogenic and regressed testes were assessed from 2 adult individuals collected in Arkansas in May and September of 1993. Specifically, we focused on the cellular phases of germ cell development and maturation. The germ cell morphology and developmental strategy within the germinal epithelium of M. temminckii appear similar to that of other genera of turtles previously studied. Interestingly, mitotic, meiotic, and spermiogeneic cells are nearly identical to that of other turtles studied based on light microscopy. There are also 6 recognizable steps to spermiogenesis, which is slightly different than the 7 steps of most turtles (step 7 absent). Though this study only uses 2 individuals (because of its endangered status), M. temminckii appears to start spermatogenesis in the spring, and the climax of spermiogenesis occurs in the fall similar to that of other temperate turtles studied to date based on light microscopy. Peculiar to both turtles in this study were the regular appearance of very large germ cells in the basal compartment of the germinal epithelium. Based on previous research and our histological analysis these enlarged spermatogonia exhibit hypertrophic characteristics typical of cells undergoing apoptosis
Investigation of Traditional and Alternate Living Hinge Designs for Fused Deposition Modeling Additive Manufacturing Process
A manuscript-style thesis composed of three studies covered the application of living hinge designs in the additive manufacturing process of fused deposition modeling. Initial research included comparing numerical and analytical linear analyses on a traditional living hinge design. The second research consisted of tensile testing for the material properties of the Acrylonitrile Butadiene Styrene (ABS) used in fused deposition modeling (FDM) process by the MakerBot 2X as well as adjusting the traditional design to be printed. The third study explored alternate living hinge designs that utilize the geometric freedom provided by additive manufacturing to more evenly distribute stress across the hinge. The traditional living hinge design is not feasible for FDM ABS while alternate designs such as a longer hinge length or wave pattern demonstrated minimal stress experienced across the hinge. Further research on optimizing alternate designs is encouraged
THE PERCEIVED USEFULNESS OF PODCASTING IN HIGHER EDUCATION: A SURVEY OF STUDENTS\u27 ATTITUDES AND INTENTION TO USE
Because of the infancy of podcasting, its effectiveness and acceptance as an educational tool is not well understood. After providing an overview of podcasting technologies and current uses of podcasting in higher education, this paper will present the results of a study that investigates students’ potential acceptance of podcasting as an educational tool. The survey, which was based on constructs from the Technology Acceptance Model (Davis et al. 1989), was administered in early 2006 to graduate Management Information Systems students. Results suggest that students perceive podcasting to be a useful educational tool, but they question its potential effectiveness in improving their performance as student-learners
The Effects of Religious Fundamentalism and Threat on Prejudice
The study investigated the relation of religious fundamentalism (RF) and prejudice in the presence of two threat conditions: epistemic uncertainty, introduced via threat to beliefs, and existential threat, presented through mortality salience induction. A model of RF as a belief system adopted to manage uncertainty and threat was also presented. Participants were 396 undergraduates, 192 of whom met inclusion requirements. RF was significantly related to prejudice toward women, toward homosexual individuals, and toward other religions, the latter relationship being strongest. No significant effects for threat condition were found. Results indicate that the uncertainty and/or threat introduced by the target groups varied in magnitude and that this uncertainty and/or threat was stronger than that posed by the threat conditions
Using Multimedia Online Learning Tools to Supplement the Classroom Instruction
This paper introduces the use of multimedia tools to create an online self-study environment to supplement the classroom instruction in Graphical Communications. The topics in this course extend from hand sketching demonstrations to the solid model creation using CAD software such as CATIA. Webcam and Camtasia software were used to capture live examples and the recorded videos were placed on Blackboard. Multimedia tools provide students an efficient way to review the topics covered in the class, in that hand sketching and complex CAD models are often difficult to interpret through words and pictures alone. The positive survey results reflect an initial success of using multimedia tools to supplement the classroom instruction
Driving Satisfaction with IT Services and Investment in IT through Business-IT Alignment
Research has shown that business-IT alignment is an important issue for organizations that wish to allocate their information technology investments appropriately, but less is known about the impact that business-IT alignment has on the satisfaction and motivation of employees. This study investigates the impact that business-IT alignment has on an organizational leader’s satisfaction with the IT services within an organization and the amount of investment allocated for IT. In addition, the study looks at the impact that IT investment has on the motivation of IT leaders. Surveys of both IT leaders and organizational leaders within the same organization were conducted. Findings suggest that business-IT alignment influences organizational leaders’ satisfaction with IT which influences their willingness to invest in IT initiatives. However, the job motivation of IT leaders is not influenced by the amount of investment in IT
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