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• 8411. [Article] The Construction and Deconstruction of Signaling Systems that Regulate Mitotic Spindle Positioning

  Signaling systems regulate the flow of cellular information by organizing proteins in space and time to coordinate a variety of cellular activities that are critical for the proper development, function, ...

  Citation × Citation Citation Abstract Copy Title: The Construction and Deconstruction of Signaling Systems that Regulate Mitotic Spindle Positioning Author: Lu, Michelle Year: 2013, 2014 Signaling systems regulate the flow of cellular information by organizing proteins in space and time to coordinate a variety of cellular activities that are critical for the proper development, function, and maintenance of cells. Signaling molecules can exhibit several levels of complexity through the utilization of modular protein interactions, which can generate simple linear behaviors or complex behaviors such as ultrasensitivity. Protein modularity also serves as the basis for the vast protein networks that form the regulatory networks that govern several biological activities. My work focuses on the importance of protein modularity in complex biological systems, in particular the regulatory pathways of spindle positioning. The first part of my work involves the construction of a synthetic regulatory network using modular protein interactions in an effort to understand the complex behavior of the natural spindle orientation regulator Pins. Utilizing well-characterized protein domains and their binding partners, I built an autoinhibited protein switch that can be activated by a small protein domain. We found that the input-output relationship of the synthetic protein switch could be tuned by the simple addition of "decoy" domains, domains that bind and sequester input signal, thereby impeding the onset of the output response to generate an input threshold. By varying the number and affinities of the decoy domains, we found that we could transform a simple linear response into a complex, ultrasensitive one. Thus, modular protein interactions can serve as a source of complex behaviors. The second part of my work focuses on elucidating the molecular mechanisms underlying spindle positioning in the Drosophila neuroblast. I found that Pins orients the mitotic spindle by coordinating two opposite-polarity microtubule motors Dynein and Kinesin-73 through its multiple domains. Kinesin-73 also relies on its modular domain architecture to perform its duties in Pins-mediated spindle positioning, where its N-terminal half functions in coordinating cortical-microtubule capture while its C-terminal half functions as a region necessary for the activation of Dynein. Thus, modular protein design allows for the organization of spindle orientation regulators in space to achieve the complex biological activity that is spindle positioning. This dissertation includes previously published and unpublished coauthored material. Title: The Construction and Deconstruction of Signaling Systems that Regulate Mitotic Spindle Positioning Author: Lu, Michelle Year: 2013, 2014 Signaling systems regulate the flow of cellular information by organizing proteins in space and time to coordinate a variety of cellular activities that are critical for the proper development, function, and maintenance of cells. Signaling molecules can exhibit several levels of complexity through the utilization of modular protein interactions, which can generate simple linear behaviors or complex behaviors such as ultrasensitivity. Protein modularity also serves as the basis for the vast protein networks that form the regulatory networks that govern several biological activities. My work focuses on the importance of protein modularity in complex biological systems, in particular the regulatory pathways of spindle positioning. The first part of my work involves the construction of a synthetic regulatory network using modular protein interactions in an effort to understand the complex behavior of the natural spindle orientation regulator Pins. Utilizing well-characterized protein domains and their binding partners, I built an autoinhibited protein switch that can be activated by a small protein domain. We found that the input-output relationship of the synthetic protein switch could be tuned by the simple addition of "decoy" domains, domains that bind and sequester input signal, thereby impeding the onset of the output response to generate an input threshold. By varying the number and affinities of the decoy domains, we found that we could transform a simple linear response into a complex, ultrasensitive one. Thus, modular protein interactions can serve as a source of complex behaviors. The second part of my work focuses on elucidating the molecular mechanisms underlying spindle positioning in the Drosophila neuroblast. I found that Pins orients the mitotic spindle by coordinating two opposite-polarity microtubule motors Dynein and Kinesin-73 through its multiple domains. Kinesin-73 also relies on its modular domain architecture to perform its duties in Pins-mediated spindle positioning, where its N-terminal half functions in coordinating cortical-microtubule capture while its C-terminal half functions as a region necessary for the activation of Dynein. Thus, modular protein design allows for the organization of spindle orientation regulators in space to achieve the complex biological activity that is spindle positioning. This dissertation includes previously published and unpublished coauthored material. Close

• 8412. [Article] Coupling Nitrogen Vacancy Centers in Diamond Nanopillars Whispering Gallery Microresonators

  For cavity quantum electrodynamics systems (cavity-QED) to play a role in quantum information processing applications and in quantum networks, they must be robust and scalable in addition to having a suitable ...

  Citation × Citation Citation Abstract Copy Title: Coupling Nitrogen Vacancy Centers in Diamond Nanopillars Whispering Gallery Microresonators Author: Dinyari, Khodadad Year: 2013 For cavity quantum electrodynamics systems (cavity-QED) to play a role in quantum information processing applications and in quantum networks, they must be robust and scalable in addition to having a suitable method for the generation, processing and storage of quantum bits. One solution is to develop a composite system that couples a nitrogen vacancy (NV) center in diamond to a whispering gallery mode supported by a fused silica microsphere. Such a system is motivated by the optical and electron-spin properties of the NV center. The NV center is the leading spin-qubit and exhibits atomic like linewidths at cryogenic temperatures and has spin coherence times greater than milliseconds at room temperature. These long coherence times, coupled with nanosecond scale spin readout and manipulation times, allow for millions of quantum operations to be processed. Silica whispering gallery resonators are the only class of microresonators with quality factor high enough to reach the strong coupling regime, which is necessary for some quantum information processing applications. Integrating these two components into a system that could position a diamond nanopillar near the surface of a deformed-double stemmed microsphere system, with nanometer precision, at 10 K was a major achievement of this research. Cavity resonances in deformed microspheres can be excited with a free-space coupling technique which simplifies their integration into cryogenic environments. In these intentionally deformed resonators, an enhanced evanescent field decay length was observed at specific locations along the ray orbit. The double-stem arrangement enables the cavity resonance to be tuned over 450 GHz, with sub-10 MHz resolution, at 10 K. These two features, the enhanced decay length and broad range tuning with high resolution, are indispensible tools for cavity-QED studies with silica microspheres. Diamond nanopillars were fabricated from single crystal diamond with diameters as small as 140 nm in order to maintain a high quality factor. Studies were conducted on NV centers in nanopillars and bulk diamond to determine their suitability for cavity-QED applications. In an attempt to increase the light-matter interaction between NV centers and whispering gallery modes, diamond substrates were optically characterized that were irradiated with nitrogen ions. Title: Coupling Nitrogen Vacancy Centers in Diamond Nanopillars Whispering Gallery Microresonators Author: Dinyari, Khodadad Year: 2013 For cavity quantum electrodynamics systems (cavity-QED) to play a role in quantum information processing applications and in quantum networks, they must be robust and scalable in addition to having a suitable method for the generation, processing and storage of quantum bits. One solution is to develop a composite system that couples a nitrogen vacancy (NV) center in diamond to a whispering gallery mode supported by a fused silica microsphere. Such a system is motivated by the optical and electron-spin properties of the NV center. The NV center is the leading spin-qubit and exhibits atomic like linewidths at cryogenic temperatures and has spin coherence times greater than milliseconds at room temperature. These long coherence times, coupled with nanosecond scale spin readout and manipulation times, allow for millions of quantum operations to be processed. Silica whispering gallery resonators are the only class of microresonators with quality factor high enough to reach the strong coupling regime, which is necessary for some quantum information processing applications. Integrating these two components into a system that could position a diamond nanopillar near the surface of a deformed-double stemmed microsphere system, with nanometer precision, at 10 K was a major achievement of this research. Cavity resonances in deformed microspheres can be excited with a free-space coupling technique which simplifies their integration into cryogenic environments. In these intentionally deformed resonators, an enhanced evanescent field decay length was observed at specific locations along the ray orbit. The double-stem arrangement enables the cavity resonance to be tuned over 450 GHz, with sub-10 MHz resolution, at 10 K. These two features, the enhanced decay length and broad range tuning with high resolution, are indispensible tools for cavity-QED studies with silica microspheres. Diamond nanopillars were fabricated from single crystal diamond with diameters as small as 140 nm in order to maintain a high quality factor. Studies were conducted on NV centers in nanopillars and bulk diamond to determine their suitability for cavity-QED applications. In an attempt to increase the light-matter interaction between NV centers and whispering gallery modes, diamond substrates were optically characterized that were irradiated with nitrogen ions. Close

• 8413. [Article] Storming the Security Council: The Revolution in UNSC Authority Over the Projection of Military Force

  Why have states requested international authorization for their projections of military force more after 1989? One perspective suggests powerful states should not make such requests. Rather, they should ...

  Citation × Citation Citation Abstract Copy Title: Storming the Security Council: The Revolution in UNSC Authority Over the Projection of Military Force Author: Cleveland, Clayton Year: 2013 Why have states requested international authorization for their projections of military force more after 1989? One perspective suggests powerful states should not make such requests. Rather, they should look to their own power instead of international organizations. Another view suggests international authorization is a way to provide credible signals about state intentions. A third perspective suggests states view international authorization of military force as appropriate. I establish that states have changed their behavior, requesting international authorization more often after 1989. Then, I develop hypotheses involving material power, burden-sharing, informational signaling, and international norms. I assess their ability to explain the increase in authorization requests through evidence from over 150 military force projections by a wide range of states and through a detailed evaluation of United States behavior. The U.S. provides a strong test case for the theories evaluated, since powerful states should be least susceptible to pressures for requesting authorization, and yet it does so more frequently after 1989. I find the expectation that states should request international authorization emerged after the U.S. set a precedent during the Persian Gulf War. The end of the Cold War changed the perceived "viability" of different strategies for projecting military force for U.S. policy-makers. Requesting authorization from the UN became a plausible alternative. The decision to request international authorization--and the justifications U.S. decision makers offered for doing so--led to the expectation by other states that the U.S. would do so for future projections of military force. This international norm helps explain the politics of international authorization for the airstrikes on Iraq (1998), the Iraq War (2003) and the Libyan intervention (2011). The response of other countries to the Clinton Administration's failure to request authorization for airstrikes on Iraq in 1998 demonstrates that expectations regarding whether the U.S. should request authorization had shifted. The subsequent consolidation of the norm helps explain the requests for authorization by the Bush Administration for the Iraq War in 2003 and by the Obama Administration for Libya in 2011. The dissertation increases our understanding of the relationship, and the role of authority, between states and international organizations. Title: Storming the Security Council: The Revolution in UNSC Authority Over the Projection of Military Force Author: Cleveland, Clayton Year: 2013 Why have states requested international authorization for their projections of military force more after 1989? One perspective suggests powerful states should not make such requests. Rather, they should look to their own power instead of international organizations. Another view suggests international authorization is a way to provide credible signals about state intentions. A third perspective suggests states view international authorization of military force as appropriate. I establish that states have changed their behavior, requesting international authorization more often after 1989. Then, I develop hypotheses involving material power, burden-sharing, informational signaling, and international norms. I assess their ability to explain the increase in authorization requests through evidence from over 150 military force projections by a wide range of states and through a detailed evaluation of United States behavior. The U.S. provides a strong test case for the theories evaluated, since powerful states should be least susceptible to pressures for requesting authorization, and yet it does so more frequently after 1989. I find the expectation that states should request international authorization emerged after the U.S. set a precedent during the Persian Gulf War. The end of the Cold War changed the perceived "viability" of different strategies for projecting military force for U.S. policy-makers. Requesting authorization from the UN became a plausible alternative. The decision to request international authorization--and the justifications U.S. decision makers offered for doing so--led to the expectation by other states that the U.S. would do so for future projections of military force. This international norm helps explain the politics of international authorization for the airstrikes on Iraq (1998), the Iraq War (2003) and the Libyan intervention (2011). The response of other countries to the Clinton Administration's failure to request authorization for airstrikes on Iraq in 1998 demonstrates that expectations regarding whether the U.S. should request authorization had shifted. The subsequent consolidation of the norm helps explain the requests for authorization by the Bush Administration for the Iraq War in 2003 and by the Obama Administration for Libya in 2011. The dissertation increases our understanding of the relationship, and the role of authority, between states and international organizations. Close

• 8414. [Article] The Disproportionate Use of Discipline: An Investigation of the Potential Impact of School-wide Positive Behavioral Interventions and Supports

  Over the last 35 years, the disproportionate use of discipline by gender, race/ethnicity, and disability status has been consistently documented. Specifically, Black males receive the majority of suspensions ...

  Citation × Citation Citation Abstract Copy Title: The Disproportionate Use of Discipline: An Investigation of the Potential Impact of School-wide Positive Behavioral Interventions and Supports Author: Guardino, David Year: 2013 Over the last 35 years, the disproportionate use of discipline by gender, race/ethnicity, and disability status has been consistently documented. Specifically, Black males receive the majority of suspensions and expulsions. Discipline for Native American and Hispanic students, while often showing overrepresentation, is less consistent. There is however consistent evidence of disproportionate discipline for students with disabilities. Experiencing disproportionate discipline often leads to poor academic outcomes, drop out, and involvement in the juvenile justice system. The literature on disproportionate discipline does point to practices that may mitigate its occurrence. These include: shifting from reactive policies and practices to prevention frameworks, developing consistency for how consequences are delivered, reviewing behavioral data, and using graduated support. School-Wide Positive Behavioral Interventions and Supports (SWPBIS) is a systems approach focusing on whole-school prevention of problem behavior through teaching and acknowledgement of appropriate behavior, consistent consequences, and data for decision-making within graduated levels of support. The purpose of this study was to investigate the extent of disproportionate discipline in Oregon middle schools and explore the potential impact that SWPBIS may have on discipline rates. Results from descriptive analysis of discipline data by gender, race/ethnicity, and disability status across 181 middle schools in Oregon showed that Black, Native American, and Hispanic students were overrepresented for suspension and expulsion. Specifically, Black students were 2.58 times more likely to receive out-of-school suspension and 2.79 times more likely to be expelled as all other students. In addition, Native American and Hispanic students were over 1.5 times more likely to be suspended or expelled as all other students. In contrast, White and Asian students were less likely to be suspended and half as likely to be expelled as all other students. Also, students with disabilities were nearly two times more likely to be suspended and 1.55 times more likely to be expelled as students without disabilities. Lastly, ANOVA results for a causal-comparative matched group design with SWPBIS level of implementation as the independent variable showed no statistically significant differences between groups for suspension or expulsion. Possible reasons for these findings are explored and implications for future research and policy are provided. Title: The Disproportionate Use of Discipline: An Investigation of the Potential Impact of School-wide Positive Behavioral Interventions and Supports Author: Guardino, David Year: 2013 Over the last 35 years, the disproportionate use of discipline by gender, race/ethnicity, and disability status has been consistently documented. Specifically, Black males receive the majority of suspensions and expulsions. Discipline for Native American and Hispanic students, while often showing overrepresentation, is less consistent. There is however consistent evidence of disproportionate discipline for students with disabilities. Experiencing disproportionate discipline often leads to poor academic outcomes, drop out, and involvement in the juvenile justice system. The literature on disproportionate discipline does point to practices that may mitigate its occurrence. These include: shifting from reactive policies and practices to prevention frameworks, developing consistency for how consequences are delivered, reviewing behavioral data, and using graduated support. School-Wide Positive Behavioral Interventions and Supports (SWPBIS) is a systems approach focusing on whole-school prevention of problem behavior through teaching and acknowledgement of appropriate behavior, consistent consequences, and data for decision-making within graduated levels of support. The purpose of this study was to investigate the extent of disproportionate discipline in Oregon middle schools and explore the potential impact that SWPBIS may have on discipline rates. Results from descriptive analysis of discipline data by gender, race/ethnicity, and disability status across 181 middle schools in Oregon showed that Black, Native American, and Hispanic students were overrepresented for suspension and expulsion. Specifically, Black students were 2.58 times more likely to receive out-of-school suspension and 2.79 times more likely to be expelled as all other students. In addition, Native American and Hispanic students were over 1.5 times more likely to be suspended or expelled as all other students. In contrast, White and Asian students were less likely to be suspended and half as likely to be expelled as all other students. Also, students with disabilities were nearly two times more likely to be suspended and 1.55 times more likely to be expelled as students without disabilities. Lastly, ANOVA results for a causal-comparative matched group design with SWPBIS level of implementation as the independent variable showed no statistically significant differences between groups for suspension or expulsion. Possible reasons for these findings are explored and implications for future research and policy are provided. Close

• 8415. [Article] Children's and Adults' Prosocial Behavior in Real and Imaginary Social Interactions

  In everyday life, there are many situations that elicit emotional reactions to an individual's plight, leading to empathic thoughts and helping behaviors. But what if the observed situation involves fictional ...

  Citation × Citation Citation Abstract Copy Title: Children's and Adults' Prosocial Behavior in Real and Imaginary Social Interactions Author: Sachet, Alison Year: 2013 In everyday life, there are many situations that elicit emotional reactions to an individual's plight, leading to empathic thoughts and helping behaviors. But what if the observed situation involves fictional characters rather than real life people? The main goal of this dissertation was to investigate the extent that empathic thoughts and helping behaviors characterize children's responses to fictional social interactions, as well as to real ones. Another goal was to develop a new measure of prosocial behavior. In Study 1, 60 undergraduate students (36 female; Mage = 19.87, SDage = 4.46) played two computerized ball-tossing games, one with 3 co-players who were believed to be other students and one in which a ball was tossed between 3 walls. During the second half of each game, one of the co-players/walls was excluded by the other two co-players/walls; the participant's subsequent increase in passes to the excluded co-player/wall was recorded. Participants increased their passes to the excluded real co-player more than to the excluded wall, indicating that the increase in the Real Condition were attempts to help another person, rather than simply to even out the distribution of passes. Study 2 extended these findings to children and tested the relationship between reactions to real and fictional social interactions. Seventy-one 5- and 8-year-old children (36 females; 35 5-year-olds: Mage = 5 years, 8.2 months, SDage = 2.4 months; 36 8-year-olds: Mage = 8 years, 6.5 months, SDage = 2.9 months) played the computerized ball tossing game with (1) other children they believed to be real, (2) novel cartoon characters, and (3) walls. One of the co-players/walls was excluded in the second half of each game. Although children reported similar empathic reactions towards the excluded real and fictional co-players, they increased their passes to the excluded real co-player more than to the excluded fictional character or wall (controlling for individual differences in real life empathy). These results suggest that children's emotional reactions to what they experience in fiction and in real life are similar, but they take the behavioral steps to help another individual only when that individual is believed to be a real person. Title: Children's and Adults' Prosocial Behavior in Real and Imaginary Social Interactions Author: Sachet, Alison Year: 2013 In everyday life, there are many situations that elicit emotional reactions to an individual's plight, leading to empathic thoughts and helping behaviors. But what if the observed situation involves fictional characters rather than real life people? The main goal of this dissertation was to investigate the extent that empathic thoughts and helping behaviors characterize children's responses to fictional social interactions, as well as to real ones. Another goal was to develop a new measure of prosocial behavior. In Study 1, 60 undergraduate students (36 female; Mage = 19.87, SDage = 4.46) played two computerized ball-tossing games, one with 3 co-players who were believed to be other students and one in which a ball was tossed between 3 walls. During the second half of each game, one of the co-players/walls was excluded by the other two co-players/walls; the participant's subsequent increase in passes to the excluded co-player/wall was recorded. Participants increased their passes to the excluded real co-player more than to the excluded wall, indicating that the increase in the Real Condition were attempts to help another person, rather than simply to even out the distribution of passes. Study 2 extended these findings to children and tested the relationship between reactions to real and fictional social interactions. Seventy-one 5- and 8-year-old children (36 females; 35 5-year-olds: Mage = 5 years, 8.2 months, SDage = 2.4 months; 36 8-year-olds: Mage = 8 years, 6.5 months, SDage = 2.9 months) played the computerized ball tossing game with (1) other children they believed to be real, (2) novel cartoon characters, and (3) walls. One of the co-players/walls was excluded in the second half of each game. Although children reported similar empathic reactions towards the excluded real and fictional co-players, they increased their passes to the excluded real co-player more than to the excluded fictional character or wall (controlling for individual differences in real life empathy). These results suggest that children's emotional reactions to what they experience in fiction and in real life are similar, but they take the behavioral steps to help another individual only when that individual is believed to be a real person. Close

• 8416. [Article] A Grammar of Bih

  Bih is a Chamic (Austronesian) language spoken by approximately 500 people in the Southern highlands of Vietnam. This dissertation is the first descriptive grammar of the language, based on extensive fieldwork ...

  Citation × Citation Citation Abstract Copy Title: A Grammar of Bih Author: Nguyen, Tam Year: 2013 Bih is a Chamic (Austronesian) language spoken by approximately 500 people in the Southern highlands of Vietnam. This dissertation is the first descriptive grammar of the language, based on extensive fieldwork and community-based language documentation in Vietnam and written from a functional/typological perspective. The analysis in this work is supported with illustrations drawn mainly from texts, with examples from elicitation when needed as well. In phonology, Bih is the only mainland Chamic language to have retained all four Proto-Chamic presyllablic vowels. As a result, Bih is the only Chamic language having only primary clusters inherited from Proto-Chamic and lacks the secondary clusters created by a reduction of an original disyllable form in Proto-Chamic, which occur in other languages of the family. In addition to the vowels, Bih retains only six out of thirteen Proto-Chamic presyllable consonants, but it retains all main syllable consonants from Proto-Chamic. In addition, all voiced "aspirated" consonants in Proto-Chamic become voiceless in Bih. This phonological change is common throughout coastal Chamic and it is also shared among Bih and other two highland Chamic languages, Chru and Northern Roglai, but not with Ede. In morphological terms, Bih is an isolating language. Words are mostly monosyllabic, although there are a number of disyllable or trisyllable words with the fossilized prefixes pa- or ma- or both. Without inflection on verbs, like other mainland Southeast Asian languages, Bih includes a set of particles functioning as grammatical markers. In fact, many Bih words function as either a full lexical verb or particle depending on their syntactic behaviors. The fundamental mechanisms of Bih syntax are clause-chaining and verb serialization. Most grammatical forms develop from serial verb source constructions. Another feature of great areal typological interest is the topic and focus distinction system of Bih, which, in combination with word order alternations, indicates the discourse status of a referent: whether it is new and/or important in the discourse, or the speaker's evaluation of whether or not a referent is accessible to the mind of the hearer, or whether it contradicts a presupposition or expectation on the part of the hearer or of people in general. Bih has a very interesting obviative-like system, which uses one third person pronoun form to refer to the character whose point of view is being represented and another for all other third persons. Title: A Grammar of Bih Author: Nguyen, Tam Year: 2013 Bih is a Chamic (Austronesian) language spoken by approximately 500 people in the Southern highlands of Vietnam. This dissertation is the first descriptive grammar of the language, based on extensive fieldwork and community-based language documentation in Vietnam and written from a functional/typological perspective. The analysis in this work is supported with illustrations drawn mainly from texts, with examples from elicitation when needed as well. In phonology, Bih is the only mainland Chamic language to have retained all four Proto-Chamic presyllablic vowels. As a result, Bih is the only Chamic language having only primary clusters inherited from Proto-Chamic and lacks the secondary clusters created by a reduction of an original disyllable form in Proto-Chamic, which occur in other languages of the family. In addition to the vowels, Bih retains only six out of thirteen Proto-Chamic presyllable consonants, but it retains all main syllable consonants from Proto-Chamic. In addition, all voiced "aspirated" consonants in Proto-Chamic become voiceless in Bih. This phonological change is common throughout coastal Chamic and it is also shared among Bih and other two highland Chamic languages, Chru and Northern Roglai, but not with Ede. In morphological terms, Bih is an isolating language. Words are mostly monosyllabic, although there are a number of disyllable or trisyllable words with the fossilized prefixes pa- or ma- or both. Without inflection on verbs, like other mainland Southeast Asian languages, Bih includes a set of particles functioning as grammatical markers. In fact, many Bih words function as either a full lexical verb or particle depending on their syntactic behaviors. The fundamental mechanisms of Bih syntax are clause-chaining and verb serialization. Most grammatical forms develop from serial verb source constructions. Another feature of great areal typological interest is the topic and focus distinction system of Bih, which, in combination with word order alternations, indicates the discourse status of a referent: whether it is new and/or important in the discourse, or the speaker's evaluation of whether or not a referent is accessible to the mind of the hearer, or whether it contradicts a presupposition or expectation on the part of the hearer or of people in general. Bih has a very interesting obviative-like system, which uses one third person pronoun form to refer to the character whose point of view is being represented and another for all other third persons. Close

• 8417. [Article] Synthesizing New [(SnSe)1.15]m(TSe2)n, [(SnSe)1.16]m(VSe2)n[(SnSe)1.16]p(TaSe2)q, and (SnSe)1.16(V.51Ta.49Se2) Intergrowth Compounds (T = V and Ta)

  A modification of the modulated elemental reactants synthetic technique was developed and used to synthesize several new layered compounds. Several TSe2, [(SnSe)1+y]m(TSe2)n, [(SnSe)1+y]m(TSe2)n[(SnSe)1+y]p(T'Se2)q, ...

  Citation × Citation Citation Abstract Copy Title: Synthesizing New [(SnSe)1.15]m(TSe2)n, [(SnSe)1.16]m(VSe2)n[(SnSe)1.16]p(TaSe2)q, and (SnSe)1.16(V.51Ta.49Se2) Intergrowth Compounds (T = V and Ta) Author: Atkins, Ryan Year: 2013 A modification of the modulated elemental reactants synthetic technique was developed and used to synthesize several new layered compounds. Several TSe2, [(SnSe)1+y]m(TSe2)n, [(SnSe)1+y]m(TSe2)n[(SnSe)1+y]p(T'Se2)q, and (SnSe)1+y(V1-xTaxSe2) layered compounds were synthesized by the new modulated elemental reactant (MER) technique with T = V, Ta, and Ti. The MER approach is a low-temperature synthesis that allows the kinetic trapping of metastable compounds, allowing a designed synthesis with control over the value of m, n, p, and q. These layered compounds were structurally characterized by X-ray diffraction and transmission electron microscopy studies. Each integer increase of m, n, p, and q resulted in a linear increase in thickness, representing the single structural units of SnSe (a Sn/Se atomic bilayer) and TSe2 (an X-T-X trilayer sandwich). All of the compounds contained preferentially oriented layering, with the layer's (00l) plane parallel to the substrate surface. From Bragg-Brentano and in-plane X-ray diffraction studies, the layers are found to be regularly spaced along c with abrupt interfaces and contain crystallinity in their ab-plane. Many of these layered compounds were found to exhibit turbostratic disorder, a random rotational disorder that is usually present in materials made by the MER technique. The presence of turbostratic disorder was found to be dependent on the polytypes that exist in the bulk form of the TSe2 constituent. The electrical properties of the layered compounds were studied by means of temperature-dependent resistivity and Hall measurements. Interesting electrical properties were found as a result of the turbostratic disorder, including a charge density wave transition found in the [(SnSe)1.15]m(VSe2) ferecrystal. The onset temperature of the CDW transition was found to be a sensitive function of the layering sequence, increasing with higher m values. The CDW transition was attributed to the VSe2 constituent and was found in all the composite crystals that contained VSe2. It was found that the [(SnSe)1+y]m(VSe2)n and [(SnSe)1+y]m(TaSe2)n intergrowths could be combined into an ABCB layered [(SnSe)1+y]m(VSe2)n[(SnSe)1+y]p(TaSe2)q intergrowth, with chemical separation of the VSe2 and TaSe2 constituents. This dissertation includes previously published and unpublished co-authored material. Title: Synthesizing New [(SnSe)1.15]m(TSe2)n, [(SnSe)1.16]m(VSe2)n[(SnSe)1.16]p(TaSe2)q, and (SnSe)1.16(V.51Ta.49Se2) Intergrowth Compounds (T = V and Ta) Author: Atkins, Ryan Year: 2013 A modification of the modulated elemental reactants synthetic technique was developed and used to synthesize several new layered compounds. Several TSe2, [(SnSe)1+y]m(TSe2)n, [(SnSe)1+y]m(TSe2)n[(SnSe)1+y]p(T'Se2)q, and (SnSe)1+y(V1-xTaxSe2) layered compounds were synthesized by the new modulated elemental reactant (MER) technique with T = V, Ta, and Ti. The MER approach is a low-temperature synthesis that allows the kinetic trapping of metastable compounds, allowing a designed synthesis with control over the value of m, n, p, and q. These layered compounds were structurally characterized by X-ray diffraction and transmission electron microscopy studies. Each integer increase of m, n, p, and q resulted in a linear increase in thickness, representing the single structural units of SnSe (a Sn/Se atomic bilayer) and TSe2 (an X-T-X trilayer sandwich). All of the compounds contained preferentially oriented layering, with the layer's (00l) plane parallel to the substrate surface. From Bragg-Brentano and in-plane X-ray diffraction studies, the layers are found to be regularly spaced along c with abrupt interfaces and contain crystallinity in their ab-plane. Many of these layered compounds were found to exhibit turbostratic disorder, a random rotational disorder that is usually present in materials made by the MER technique. The presence of turbostratic disorder was found to be dependent on the polytypes that exist in the bulk form of the TSe2 constituent. The electrical properties of the layered compounds were studied by means of temperature-dependent resistivity and Hall measurements. Interesting electrical properties were found as a result of the turbostratic disorder, including a charge density wave transition found in the [(SnSe)1.15]m(VSe2) ferecrystal. The onset temperature of the CDW transition was found to be a sensitive function of the layering sequence, increasing with higher m values. The CDW transition was attributed to the VSe2 constituent and was found in all the composite crystals that contained VSe2. It was found that the [(SnSe)1+y]m(VSe2)n and [(SnSe)1+y]m(TaSe2)n intergrowths could be combined into an ABCB layered [(SnSe)1+y]m(VSe2)n[(SnSe)1+y]p(TaSe2)q intergrowth, with chemical separation of the VSe2 and TaSe2 constituents. This dissertation includes previously published and unpublished co-authored material. Close

• 8418. [Article] Stem Cell Self-renewal and Neuronal Differentiation in the <italic>Drosophila</italic> Central Nervous System

  The adoption and subsequent retention of distinct cellular fates upon cell division is a critical phenomenon in the development of multicellular organisms. A well-studied example of this process is stem ...

  Citation × Citation Citation Abstract Copy Title: Stem Cell Self-renewal and Neuronal Differentiation in the <italic>Drosophila</italic> Central Nervous System Author: Carney, Travis Year: 2013 The adoption and subsequent retention of distinct cellular fates upon cell division is a critical phenomenon in the development of multicellular organisms. A well-studied example of this process is stem cell divisions; stem cells must possess the capacity to self-renew in order to maintain a stem cell population, as well as to generate differentiated daughters for tissue growth and repair. Drosophila neuroblasts are the neural stem cells of the central nervous system and have emerged as an important model for stem cell divisions and the genetic control of daughter cell identities. Neuroblasts divide asymmetrically to generate daughters with distinct fates; one retains a neuroblast identity and the other, a ganglion mother cell, divides only once more to generate differentiated neurons and glia. Perturbing the asymmetry of neuroblast divisions can result in the failure to self-renew and the loss of the neural stem cell population; alternatively, ectopic self-renewal can occur, resulting in excessive neuroblast proliferation and tumorigenesis. Several genetic lesions have been characterized which cause extensive ectopic self-renewal, resulting in brains composed of neuroblasts at the expense of differentiated cells. This contrasts with wild type brains, which are composed mostly of differentiated cells and only a small pool of neuroblasts. We made use of these mutants by performing a series of microarray experiments comparing mutant brains (consisting mostly of neuroblasts) to wild type brains (which are mostly neurons). Using this approach, we generated lists of over 1000 putatively neuroblast-expressed genes and over 1000 neuronal genes; in addition, we were able to compare the transcriptional output of different mutants to infer the neuroblast subtype specificity of some of the transcripts. Finally, we verified the self-renewal function of a subset of the neuroblast genes using an RNAi-based screen, resulting in the identification of 84 putative self-renewal regulators. We went on to show that one of these genes, midlife crisis (mammals: RNF113a), is a well-conserved RNA splicing regulator which is required in postmitotic neurons for the maintenance of their differentiated state. Our data suggest that the mammalian ortholog performs the same function, implicating RNF113a as an important regulator of neuronal differentiation in humans. Title: Stem Cell Self-renewal and Neuronal Differentiation in the <italic>Drosophila</italic> Central Nervous System Author: Carney, Travis Year: 2013 The adoption and subsequent retention of distinct cellular fates upon cell division is a critical phenomenon in the development of multicellular organisms. A well-studied example of this process is stem cell divisions; stem cells must possess the capacity to self-renew in order to maintain a stem cell population, as well as to generate differentiated daughters for tissue growth and repair. Drosophila neuroblasts are the neural stem cells of the central nervous system and have emerged as an important model for stem cell divisions and the genetic control of daughter cell identities. Neuroblasts divide asymmetrically to generate daughters with distinct fates; one retains a neuroblast identity and the other, a ganglion mother cell, divides only once more to generate differentiated neurons and glia. Perturbing the asymmetry of neuroblast divisions can result in the failure to self-renew and the loss of the neural stem cell population; alternatively, ectopic self-renewal can occur, resulting in excessive neuroblast proliferation and tumorigenesis. Several genetic lesions have been characterized which cause extensive ectopic self-renewal, resulting in brains composed of neuroblasts at the expense of differentiated cells. This contrasts with wild type brains, which are composed mostly of differentiated cells and only a small pool of neuroblasts. We made use of these mutants by performing a series of microarray experiments comparing mutant brains (consisting mostly of neuroblasts) to wild type brains (which are mostly neurons). Using this approach, we generated lists of over 1000 putatively neuroblast-expressed genes and over 1000 neuronal genes; in addition, we were able to compare the transcriptional output of different mutants to infer the neuroblast subtype specificity of some of the transcripts. Finally, we verified the self-renewal function of a subset of the neuroblast genes using an RNAi-based screen, resulting in the identification of 84 putative self-renewal regulators. We went on to show that one of these genes, midlife crisis (mammals: RNF113a), is a well-conserved RNA splicing regulator which is required in postmitotic neurons for the maintenance of their differentiated state. Our data suggest that the mammalian ortholog performs the same function, implicating RNF113a as an important regulator of neuronal differentiation in humans. Close

• 8419. [Article] Quantifying Segmental Spinal Motion during Activities of Daily Living

  Back pain is a very common musculoskeletal impairment in most Americans. Average annual occurrence of back pain is reported around 30% of the population and is the most common cause of activity limitation ...

  Citation × Citation Citation Abstract Copy Title: Quantifying Segmental Spinal Motion during Activities of Daily Living Author: Breloff, Scott Year: 2013 Back pain is a very common musculoskeletal impairment in most Americans. Average annual occurrence of back pain is reported around 30% of the population and is the most common cause of activity limitation in people younger than 45 years old. Eighty percent of the back pain presents in the lumbar spine. Although this ailment is very prevalent in the American population, there is a lack of empirical evidence supporting the common clinical diagnosis and intervention back pain strategies. The frequency of back pain and the lack of treatment methods were the motivation for this investigation. It is important to better understand spine dynamics during ambulatory tasks of daily activities to identify possible biomechanical mechanisms underlying back pain. Current biomechanical quantification methods for spine dynamics are either too invasive or not detailed enough to fully comprehend detailed spinal movement. Therefore, a non-invasive but detailed procedure to calculate spine dynamics was developed and tested. In this study, multi-segmented spine dynamics (kinematics and kinetics) were calculated during four activities of daily living (level walking (W), obstacle crossing (OC), stair ascent (SA) and stair descent (SD)). Our findings suggested an in-vivo multi-segmented spine surface marker set is able to detect different and repeatable motion patterns during walking among various spinal segments. The sacrum to lower lumbar (SLL) joint had the largest range of motion (ROM) when compared to the other more superior joints (lower lumbar to upper lumbar and upper lumbar to lower thoracic). Furthermore, SA task demonstrated more flexion ROM than both W and SD tasks. In addition to task influence, joints at different spine levels also demonstrated different ROMs, where SLL had a greater ROM than upper lumbar to lower thoracic (ULLT) in the transverse plane. Age was found to not significantly affect the segmental spinal ROM or peak angles. The vertical segmental joint reaction forces were different between tasks, where SD yielded larger vertical reaction forces than W. Overall, findings from this dissertation work were able to show that a multi-segment spine marker system could be an effective tool in determining different spinal dynamics during various activities of daily living. This dissertation includes unpublished co-authored material. Title: Quantifying Segmental Spinal Motion during Activities of Daily Living Author: Breloff, Scott Year: 2013 Back pain is a very common musculoskeletal impairment in most Americans. Average annual occurrence of back pain is reported around 30% of the population and is the most common cause of activity limitation in people younger than 45 years old. Eighty percent of the back pain presents in the lumbar spine. Although this ailment is very prevalent in the American population, there is a lack of empirical evidence supporting the common clinical diagnosis and intervention back pain strategies. The frequency of back pain and the lack of treatment methods were the motivation for this investigation. It is important to better understand spine dynamics during ambulatory tasks of daily activities to identify possible biomechanical mechanisms underlying back pain. Current biomechanical quantification methods for spine dynamics are either too invasive or not detailed enough to fully comprehend detailed spinal movement. Therefore, a non-invasive but detailed procedure to calculate spine dynamics was developed and tested. In this study, multi-segmented spine dynamics (kinematics and kinetics) were calculated during four activities of daily living (level walking (W), obstacle crossing (OC), stair ascent (SA) and stair descent (SD)). Our findings suggested an in-vivo multi-segmented spine surface marker set is able to detect different and repeatable motion patterns during walking among various spinal segments. The sacrum to lower lumbar (SLL) joint had the largest range of motion (ROM) when compared to the other more superior joints (lower lumbar to upper lumbar and upper lumbar to lower thoracic). Furthermore, SA task demonstrated more flexion ROM than both W and SD tasks. In addition to task influence, joints at different spine levels also demonstrated different ROMs, where SLL had a greater ROM than upper lumbar to lower thoracic (ULLT) in the transverse plane. Age was found to not significantly affect the segmental spinal ROM or peak angles. The vertical segmental joint reaction forces were different between tasks, where SD yielded larger vertical reaction forces than W. Overall, findings from this dissertation work were able to show that a multi-segment spine marker system could be an effective tool in determining different spinal dynamics during various activities of daily living. This dissertation includes unpublished co-authored material. Close

• 8420. [Article] From Ephemeral to Legitimate: An Inquiry into Television's Material Traces in Archival Spaces, 1950s -1970s

  The dissertation offers a historical inquiry about how television's material traces entered archival spaces. Material traces refer to both the moving image products and the assortment of documentation ...

  Citation × Citation Citation Abstract Copy Title: From Ephemeral to Legitimate: An Inquiry into Television's Material Traces in Archival Spaces, 1950s -1970s Author: Bratslavsky, Lauren Year: 2013 The dissertation offers a historical inquiry about how television's material traces entered archival spaces. Material traces refer to both the moving image products and the assortment of documentation about the processes of television as industrial and creative endeavors. By identifying the development of television-specific archives and collecting areas in the 1950s to the 1970s, the dissertation contributes to television studies, specifically pointing out how television materials were conceived as cultural and historical materials "worthy" of preservation and academic study. Institutions, particularly academic and cultural institutions with archival spaces, conferred television with a status of legitimacy alongside the ascent of television studies in the 1960s and 1970s. Institutions were sites of legitimation, however, television's entrance into these archival spaces depended on the work of various individuals within academic, archival, and industrial structures who grappled with defining television's intangible archival values and dealt with material obstacles. In examining several major institutions and the factors at play in archiving television, we can trace how television was valued as worthy of academic study and conceptualized as historical evidence. The following research questions structured this historical inquiry: How did different institutions approach television as archivable in the 1950s to the 1970s? Who were the determinators within these institutions, who could conceptualize television as archivable? What were the factors that enabled television's material traces to enter archival spaces? How did television directly or indirectly enter these archival spaces? Drawing on historical methods, the research primarily examined the archives of the archives, meaning institutional documents that illuminated the archival process and perceptions about television and media. The dissertation focused on five case studies: the Museum of Modern Art, the Mass Communications History Center at the State Historical Society of Wisconsin, the Wisconsin Center for Film and Theater Research, the UCLA Film and Television Archives, and the Museum of Broadcasting. These case studies represent the various institutional contexts that applied an archival logic to television. Cultural institutions, academic archives, and industry-initiated archives worked as sites to legitimate television, transforming ephemeral broadcast moments into lasting historical and cultural material. Title: From Ephemeral to Legitimate: An Inquiry into Television's Material Traces in Archival Spaces, 1950s -1970s Author: Bratslavsky, Lauren Year: 2013 The dissertation offers a historical inquiry about how television's material traces entered archival spaces. Material traces refer to both the moving image products and the assortment of documentation about the processes of television as industrial and creative endeavors. By identifying the development of television-specific archives and collecting areas in the 1950s to the 1970s, the dissertation contributes to television studies, specifically pointing out how television materials were conceived as cultural and historical materials "worthy" of preservation and academic study. Institutions, particularly academic and cultural institutions with archival spaces, conferred television with a status of legitimacy alongside the ascent of television studies in the 1960s and 1970s. Institutions were sites of legitimation, however, television's entrance into these archival spaces depended on the work of various individuals within academic, archival, and industrial structures who grappled with defining television's intangible archival values and dealt with material obstacles. In examining several major institutions and the factors at play in archiving television, we can trace how television was valued as worthy of academic study and conceptualized as historical evidence. The following research questions structured this historical inquiry: How did different institutions approach television as archivable in the 1950s to the 1970s? Who were the determinators within these institutions, who could conceptualize television as archivable? What were the factors that enabled television's material traces to enter archival spaces? How did television directly or indirectly enter these archival spaces? Drawing on historical methods, the research primarily examined the archives of the archives, meaning institutional documents that illuminated the archival process and perceptions about television and media. The dissertation focused on five case studies: the Museum of Modern Art, the Mass Communications History Center at the State Historical Society of Wisconsin, the Wisconsin Center for Film and Theater Research, the UCLA Film and Television Archives, and the Museum of Broadcasting. These case studies represent the various institutional contexts that applied an archival logic to television. Cultural institutions, academic archives, and industry-initiated archives worked as sites to legitimate television, transforming ephemeral broadcast moments into lasting historical and cultural material. Close