Goal Directed Visual Search Based on Color Cues: Co-operative Effectes of Top-Down & Bottom-Up Visual Attention

Focus of Attention plays an important role in perception of the visual environment. Certain objects stand out in the scene irrespective of observers\u27 goals. This form of attention capture, in which stimulus feature saliency captures our attention, is of a bottom-up nature. Often prior knowledge about objects and scenes can influence our attention. This form of attention capture, which is influenced by higher level knowledge about the objects, is called top-down attention. Top-down attention acts as a feedback mechanism for the feed-forward bottom-up attention. Visual search is a result of a combined effort of the top-down (cognitive cue) system and bottom-up (low level feature saliency) system. In my thesis I investigate the process of goal directed visual search based on color cue, which is a process of searching for objects of a certain color. The computational model generates saliency maps that predict the locations of interest during a visual search. Comparison between the model-generated saliency maps and the results of psychophysical human eye -tracking experiments was conducted. The analysis provides a measure of how well the human eye movements correspond with the predicted locations of the saliency maps. Eye tracking equipment in the Visual Perceptual Laboratory in the Center for Imaging Science was used to conduct the experiments

Al-Jazeera's discourse of 'Arabness' : an examination of the discursive construction of identity in talk show programming

Al-Jazeera asserted itself in the global media scene shortly after the attacks of September 11th, 2001 in the United States. The station's regional prominence had already been entrenched in the new Arab media environment before it was overshadowed by the station's newfound global fame. Subsequently, al-Jazeera was considered an Arab media ambassador and the "voice of the Arab world." This dissertation provides an analysis of al-Jazeera's programming in Arabic that is lacking in the burgeoning English language academic literature. The dissertation furthermore highlights the way treatment of global current affairs informs a sense of Arab identification on a regional level. Moreover, it argues that, apart from competitive broadcast journalists, al-Jazeera offers an oppositional discourse of identification that does not necessarily challenge the hegemony of Western media discourses. By employing an oppositional stance expressed in typical anti-colonialist and anti-imperialist terms, it constructs an overarching notion of "Arabness" that is predominately discursive.The dissertation analyzes three live talk shows: al-Ittijah al-Mu'akis (The Opposite Direction), Bila Hudoud (Without Boundaries), and Li-Nisa' Faqat (For Women Only). These talk shows are ideal sites for examining this oppositional discourse because they constitute important forums in which perceptions of identity are cultivated in the discussion of current affairs. In my analysis, each episode is treated as a media "text" that contributes to the formation of a discourse of "Arabness." The objective of the analysis is to identify the recurrent discursive patterns and strategies in providing the basis for this discursive category of identification across Arab state borders. In constructing an oppositional discourse, the United States and Israel are employed as necessary rhetorical references; Islam is infused into "Arabness" as a homogenizing constituent in identity formation; and finally, a culturally-threatened "Arabness" converges upon a context in which the world is marked by globalization. The dissertation concludes by indicating that al-Jazeera offers merely a representation of "Arabness" that, despite its power to influence, remains one way of perceiving Arab identity

Microfluidic Reduction of Osmotic Stress in Oocyte and Zygote Vitrification.

Microfluidic cryoprotectant exchange enables vitrification of murine zygotes with superior morphology as indicated by a smoother cell surface and higher developmental competence compared to conventional methods. Bovine oocyte vitrification also benefit as evidenced by higher lipid retention. Experimental observations and mathematical analysis demonstrate that the microfluidic advantage arise predominantly from eliminating high shrinkage rates associated with abrupt and uneven exposure to vitrification solutions that readily occur in current manual protocols. The microfluidic cryoprotectant exchange method described has immediate applications for improving animal and human oocyte, zygote, and embryo cryopreservation. On a fundamental level, the clear demonstration that at the same minimum cell volume, cell shrinkage rate affects sub-lethal damage should be broadly useful for cryobiology.PhDBiomedical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/107056/1/davlai_1.pd