Before the Eye Moves: Remapping, Visual Stability and Perisaccadic Perception

Wolfe, Benjamin Arthur University of California, Berkeley 2015 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Our perception is of a stable visual world, yet we make several saccadic eye movements per second -- to say nothing of the motion of objects in the world or our own motion through the physical world. Even standing on a stage, looking out at an audience, we have the perception of the crowd in detail, in spite of our less than accurate peripheral input. Standing on this stage, it is a trivial matter to make a series of saccades to the faces of various audience members to find one particular person -- how can we do this, since visual crowding makes these faces unidentifiable? How much information is available from peripheral vision prior to a saccade? While making saccades to individual members of the crowd is useful for identifying them, what about gaining a sense of the audience as a whole? We can perceive the ensemble emotion of the audience without examining each and every member, but is this solely possible with peripheral information, the details of which we cannot otherwise access, or does it require foveal information?. While a great deal of information is available from peripheral vision, identifying individual objects is difficult due to visual crowding; we solve this problem by simply making a saccade to the object we wish to identify. The ability to saccade to a crowded object implied that a saccade to a crowded object might reduce crowding before the object was foveated, essentially unlocking peripheral information that is otherwise inaccessible. We performed a series of experiments where subjects made saccades to crowded faces and were not permitted to foveate them; we found that crowding was diminished presaccadically and that this was more effective than covert attention alone. Our crowding result shows that saccade planning can diminish crowding, but what information becomes available to conscious vision? To determine this, we performed a series of experiments to determine whether saccadic remapping acquired object representations or merely constituent features from saccade targets. We found that saccadic remapping was object-selective and tightly tuned to the target of the saccade, suggesting that, prior to a saccade, detailed information is made available to conscious vision. However, there simply is not time to take advantage of this unlocking for each face in a crowd -- can the visual system use this inaccessible information to generate a percept of the group as a whole -- an ensemble code -- and is foveation of individuals required? We occluded foveal input and determined that it was unnecessary for ensemble perception of emotion. In all, these three studies demonstrate that peripheral input is remarkably detailed and that the visual system can use this information to both facilitate identification of individual group members as part of saccade planning, and to provide a useful assessment of the crowd as a whole.

RISING FROM THE ASHES: COMMUNITY, ETHNICITY AND NATION-STATE FORMATION IN NINETEENTH-CENTURY NICARAGUA

WOLFE, JUSTIN UNIVERSITY OF CALIFORNIA, LOS ANGELES 1999 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Traditionally, nineteenth-century Nicaraguan history is divided into three periods: the years of anarchy from Independence in 1821 to 1857, the Conservative Thirty Years from 1858–1893, and the Liberal Revolution from 1893–1909. Accordingly, the divided elite fought among themselves for more than 40 years after Independence until they unified against the threat to their sovereignty in the form of U.S. mercenary William Walker. In this narrative, upon defeating him in the National War (1855–1857), Nicaragua stagnated for 30 years into a simultaneously weak, ineffective yet coercive state until Jose Santos Zelaya's regime created a truly liberal state-formation project. This study critiques this periodization and the political, social, economic and cultural history that it implies. The foundations of nation-state formation predated the National War. This proto-nationalist ideology conditioned the elite's unification during the war and for decades to come and determined its approach to the autonomous communities that resisted the state's subsequent expansion. Following the National War, the state promoted the elite ideals of “progress,” but rather than imposing them from above, as is generally held, this study finds that the state negotiated Nicaragua's future. Nation-state formation necessarily employs a populist discourse, creating a space for resistance and negotiation of the process at every level of society. Breaking with traditional approaches to nation-state formation that tend to focus on either cultural or structural transformations, I analyze how the strands of local social, economic and cultural fabric are unraveled and rewoven into the institutional fabric of the state. The analysis relies on a wide range of newly available archival sources to examine at both the municipal and national levels, how the creation of state institutions, transformations in land tenure and labor regimes, and struggles over the meaning and autonomy of ethnic identities and local communities form the foundations of the Nicaraguan nation-state. This study examines how the state's reliance on local communities to legitimize the nation-state led to the negotiated creation of localized forms of state institutions that reproduced national identity within the everyday life of the community.

ZU: The Life of a Sumerian Verb in Early Mesopotamia

Wolfe, Jared Norris University of California, Los Angeles 2015 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

The present dissertation investigates the root zu "to know" in the Sumerian texts of early Mesopotamia, ca. 2800-1600 B.C., with the aim of identifying its grammatical, syntactic and semantic characteristics. The root is treated across the Sumerian sources, but ultimately considered within the bilingual (Sumerian-Akkadian) situation of southern Mesopotamia. The adjectival and nominal forms of the root are also discussed, as well as their Akkadian counterparts. The analysis of the lexemes over a period stretching from ca. 2600-1600 BC offers interesting results in several categories (grammatical, literary, semantic), and contributes to discussions of the epistemological and practical implications associated with the concept of "knowing" in the Mesopotamian texts. While research into systems and categories of knowledge has been carried out in the field, no systematic lexical discussion of the verbal root meaning "to know" exists. This dissertation seeks to fill that lacuna. The methods employed in the dissertation lie within the well-established principles of philological and lexicographical investigation. Chapter 1 introduces the subject and reviews previous studies. Chapter 2 treats the Sumerian root zu, elucidating its formal and literary (idiomatic) characteristics. Appendices A and B document the corpus of examples consulted. Chapter 3 then discusses the derived adjectives from the root zu, likewise noting formal and literary (idiomatic) characteristics. Appendices C, D, E and F document their respective examples. Chapter 4 turns to the Akkadian root idu "to know" in bilingual and monolingual texts, in order to investigate (idiomatic) Semitic influence. It further takes up the Akkadian adjectives corresponding to those in Sumerian discussed in the third chapter. Chapter 5 enumerates personal names in Sumerian and Akkadian that employ the root "to know." A concluding chapter sums up the evidence for the individual roots and lexemes and discusses their evolution, usage and correspondence within the scribal and linguistic settings of the different textual corpora and their historical period.

Community foundations as agents of local social change

Wolfe, Rebecca Eden Stanford University 2006 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Over the past two decades community foundations have begun acknowledging themselves as local leaders and looking to place-based change methods to benefit the communities they serve. Investigating how a community foundation performs these roles provides insights into the poorly-understood realm of elites in social movement philanthropy and how intermediary social movement organizations mobilize others and institutionalize successes. To examine these issues and more, this dissertation asks: (1) What does community foundation-led local change and leadership encompass? (2) How prevalent is this leadership among community foundations? (3) How does a community foundation mobilize others and institutionalize change? (4) How effective are community foundations at leading local social change?. These questions are explored through combining data from case studies of three social change-focused initiatives of the East Bay Community Foundation (EBCF) in Oakland, California with an internet survey of U.S. community foundations. The case study analysis is based on interviews, document review, and observation from 2002 to 2006. This research draws on social movement (notably, mechanism analysis) and institutional theory to develop models of third-party mobilization and institutionalization. Some of the findings from the EBCF case studies reveal needed adjustments to accepted frameworks of emergent mobilization and institutionalization. These modifications include: mobilization by a community foundation proceeds along two consecutive tracks, internal and external; during the second phase of mobilization the community foundation places an emphasis on relational mechanisms; successful, sustained third party mobilization requires a paradigm shift on the part of the target organizations; and institutionalization of the community foundation's goals may require that the partners form a collective identity. The hybrid-elite nature of community foundations makes them structurally and relationally well-suited to facilitate these processes. Nevertheless, the survey reveals that while nearly 90% of community foundations participate in some form of community leadership, only 4% of the population are truly leaders with a social change approach. Generalists by design, risk-averse by nature, community foundations tend to shy away from true grassroots or policy engagement. The dissertation concludes with implications of the findings for community foundations interested in pursuing social change work and elaborates on propositions for future academic study.

Teacher Perception of Tasks That Enhance Data Interpretation

Wolfe, Gretchen L The University of Wisconsin - Madison 2012 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

The purpose of this study is to provide an account of teacher perception of core practice tasks in data use, particularly data interpretation. Data interpretation is critical to professional practice in planning instructional adjustments for student learning. This is a case study of four elementary teachers who provide numerous task-specific examples of data use. The findings yield a 3-phase model of tasks that support data interpretation. Phase 1 (Observation) entails collecting critical skill data from various sources and analyzing data using familiar frameworks such as standards-based criteria for core subjects. Phase 2 (Interpretation) is comprised of three core tasks: comparing scores to predetermined target ranges, contemplating student connections to curriculum, and integrating student-based information if/when students fall short of achievement targets. Phase 3 (Adjustment) involves reinforcing student learning and referring students for specialized services when warranted. Variable practices in this data use model are attributed to teacher perceptions of successful or unsuccessful students. Discussion encompasses study implications, connections to existing literature, study limitations, and extended research recommendations.

Viral Hijacking of Host E3 Ubiquitin Ligase Machinery for the Degradation of Host Antiviral Factors

Wolfe, Leslie S Yale University 2012 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

The HIV-1 virion infectivity factor (Vif) targets the cellular cytidine deaminase, A3G, for degradation by the host proteasome to enable the virus to carry out a productive infection. Vif helps HIV-1 evade the host innate immune response by hijacking a cellular E3 ubiquitin ligase composed of Cullin 5 (Cu15), ElonginB and ElonginC (EloBC). Vif mimics a host SOCS box protein, the substrate receptor component in the ligase, to accomplish this assembly. To delineate the molecular mechanism of how Vif hijacks the host ubiquitylation pathway we have probed the assembly of the ligase through biochemical and biophysical studies. We have developed a strategy to express and purify various subcomplexes of the Vif-E3 ligase, which has allowed us to not only obtain complexes containing up to five components of the ligase for biochemical studies and crystallization trials but also enabled us to explore and characterize ligase assembly in vitro. Furthermore, we have probed the selective binding of Vif to Cul5 over other cullin family members through mutational studies. The results of this work have provided insight into how HIV-1 counteracts the host immune system through selectively assembling a Cul5-based E3 ligase. The results also have paved the way for future studies by overcoming solubility issues of many components of the ligase. Additionally, we have investigated the effects of the newly identified Vif-binding factor, the core binding factor beta (CBFbeta), on ligase stability and assembly. While the exact role of CBFbeta in Vif-E3 ligase function is not fully understood, it has been shown that CBFbeta is required for Vif stabilization and for subsequent A3G degradation in vivo. Co-expression of Vif with CBFbeta results in a behaving Vif in solution, a feat previously impossible due to the insolubility of full-length Vif. The addition of CBFbeta to our repertoire of Vif binding partners has opened a door to probe the mechanisms of this crucial cellular factor as well as has expanded our abilities to obtain Vif-E3 ligase subcomplexes. Finally, we have developed a high-throughput screening assay to identify small molecule compounds that inhibit Vif-E3 ligase assembly. More specifically, we have screened 14,014 compounds for disruption of the Vif-Cul5 interface and 2,880 compounds to test for inhibition of Vif-CBFbeta binding. We have identified lead compounds and confirmed them through dose response assays and biochemical experiments. Taken together, our studies on the Vif-E3 ligase complex have expanded our understanding of the mechanism by which HIV-1 utilizes Vif to target the important cellular antiviral factor, A3G, for degradation, laid the groundwork for future in vitro studies of the Vif-E3 ligase complex, and established a strategy to identify Vif inhibitors that may lead to potential functional probes and new anti-HIV therapeutics.

Geography inservice education programs, teacher beliefs and practices, and student outcomes

Wolfe, Lois Jean Ellis Emory University 2002 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Interest in geography education has stimulated efforts to improve geography instruction in U.S. schools through inservice education programs. Little research exists concerning the effects of such programs. In this study, the relationships among geography inservice education programs, teacher beliefs and attitudes, and student outcomes were examined through quantitative and qualitative methods. The beliefs, attitudes, and teaching practices of 3 seventh-grade teachers with differing amounts of geography inservice training were compared, as well as the achievement and attitudes of their 61 students. Results included (a) few differences in teachers' beliefs and attitudes, (b) diminished geography content by non-trained teacher, (c) students' beliefs consistent with teachers' beliefs except for attitudes toward geography, (d) no differences in student achievement, and (e) critical role of contextual factors in promoting effective instruction.

If at first you don't succeed: Failure, narration, and the subsequent pursuit of opportunity in entrepreneurial firms

Wolfe, Marcus T Indiana University 2012 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Failure is a common occurrence in most organizations, even more so for those that rely heavily on innovation and R&D as key factors that influence overall success. Additionally, there exists a wealth of literature detailing how organizations utilize sense-making processes in order to interpret and understand unexpected events such as failure, and utilize that understanding to justify past, present, and future actions. This dissertation contains two studies examining a specific facet of sense-making, namely communication in the form of organizational narratives. Over the course of these studies I examine how organizations alter their narratives as a result of project failure, to gain a better understanding of how organizations analyze entrepreneurial project failure and utilize those events to influence future entrepreneurial activity. Drawing on theory regarding organizational narratives, in the first study I develop and test a model of new product development (NPD) failure, and investigate how project failures influence the content of the organizational narrative, thereby influencing subsequent levels of entrepreneurial activity. Expanding upon the first study, the second study examines in closer detail the impact that project failure can have on the content of the organizational narrative, specifically examining the influence of contextual variables on the impact that project failure has on specific aspects of the organizational narrative. In the second study I develop and test an organizational narrative model of performance events to determine the relationship between the positive and negative emotional content of the organizational narrative as well as what effects positive performance feedback has on the level of negative emotional content present within an organization's narrative.

GAMES OF POLITICAL CHANGE: REFORM-MONGERING IN THE SOVIET UNION, SOUTH AFRICA, AND JAPAN (REFORM, LEADERSHIP)

WOLFE, EUGENE LEWIS THE UNIVERSITY OF CHICAGO 1999 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Politicians often are thought to be motivated primarily by a desire to retain office, designing institutions to that end. Changes to the rules of the political game that prove detrimental to the interests of long-ruling groups therefore are of considerable theoretical significance. Existing explanations of the successful reformer's tactics emphasize either surprise and deception or bargaining to create a coalition for change. The former explains neither how a leader who employs such tactics avoids being ousted by disgruntled followers nor accounts for why some successful reformers have opted for prolonged public discussion of change. The latter is both overly optimistic about the resources available to the reformer and unable to account for cases of reform in which most of the ruling group neither desired change nor had been bought off. Missing from existing theories of reform is an appreciation for group dynamics. I argue that the reformer can use these dynamics to his advantage in three ways. First, right after assuming the leadership, the reformer can signal his competence by making a decision his colleagues disagree with but which turns out to be in the interests of the ruling group. By demonstrating trustworthiness, the leader may convince colleagues to support reform despite their strong reservations. Second, during the discussion of change, the leader can attempt to coordinate support for a plan by persuading colleagues that other options are worse. Finally, when a vote on reform is held, the leader can exacerbate the collective action problem of opponents by buying off members of the ruling group's inner circle. Reform appears most difficult when attempted in a polity long dominated by one party. Comparing successful electoral reform in Japan, the Soviet Union, and South Africa with earlier, less successful, attempts in those countries, reveals how it can come about under the most hostile circumstances. This provides a basis for analyzing less arduous types of change, leading to conclusions about the tactical desiderata of reform in various environments.

Resonance and texture coding in the rat whisker system

Wolfe, Jason Hunter University of California, San Diego 2007 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

The sense of touch provides information about the texture of an object with much better resolution than the other senses. Primates perceive texture by actively moving their fingertips over an object and encoding the resulting spatiotemporal patterns of activation of mechanoreceptors in the skin. Within the primate fingertip many types of mechanoreceptors are densely packed in the skin making it difficult to study the individual components of these complex patterns. Rats' ability to discriminate texture using the whiskers is comparable to humans using the fingertips and due to its discrete array of whiskers on the facial pad the rat whisker system offers considerable advantages for studying texture coding. However, to date, very little is known about how behaving rats actively use their whiskers to extract texture information and how this information is encoded in the nervous system. Currently there are two main hypotheses on how rats perform texture discrimination using their whiskers. In one hypothesis, whisker motion across a texture is underdamped, and texture properties drive whisker resonance as the whisker moves across a surface. In this model, the systematic variation in resonance frequency across whiskers enables texture to be encoded by the differential amplitude of vibration across whiskers. In a second, alternative hypothesis, resonance is diminished due to damping and texture information is encoded in the precise motion of each whisker across the surface. Both of these hypotheses are supported by experiments performed in anesthetized animals, however to resolve this debate it is critical to examine whisker dynamics in awake animals to determine (1) to what extent whisker resonance shapes sensory input during active whisker use and (2) how whisker dynamics reflect texture properties when the whiskers are under active muscular control. Chapter 2 of this dissertation examines whisker vibrations measured in behaving animals trained to whisk in air. We show that, in the absence of any sensory stimulus, high frequency whisker vibrations are presents and that these are filtered by whisker resonance. This suggests that, in the awake behaving animal, resonance can play a role in shaping sensory responses in the whiskers. Chapter 3 shows that active palpation onto textures can induce whisker resonance. However we argue that the degree to which resonance occurs is not dependent on the spatial properties of the texture and therefore it is unlikely to be critical for texture encoding arguing against the resonance hypothesis. We present an alternative model for texture encoding based on the magnitude of stick-slip events that were found to occur during texture palpation. We also examine the role that muscles may play in causing these stick-slip events. Chapter 4 concludes by presenting preliminary results of the neural response to stick-slip events. We show that the spiking probability of a subset of neurons is greatly increased following a texture-induced slip and that the spiking probability increases with slip acceleration, as would be required for the texture encoding hypothesis presented in chapter 3.