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• 271. [Article] Comprehensive examination of the differences in thermoregulatory and ventilatory responses between humans with and without a PFO under different environmental conditions

  The existence of a patent foramen ovale (PFO) has been known about for nearly 2,000 years. The prevalence of a PFO has been shown to be 25-40% in the general population. Despite the fact that blood flowing ...

  Citation × Citation Citation Abstract Copy Title: Comprehensive examination of the differences in thermoregulatory and ventilatory responses between humans with and without a PFO under different environmental conditions Author: Davis, James Year: 2016 The existence of a patent foramen ovale (PFO) has been known about for nearly 2,000 years. The prevalence of a PFO has been shown to be 25-40% in the general population. Despite the fact that blood flowing through a PFO acts as a shunt, there has been little research looking at the effect a PFO has on physiology in otherwise healthy humans. In Chapter IV, the effect of a PFO on core temperature (Tcore) prior to, and during exercise, was investigated. The design of this experiment included appropriate controls for a thermoregulatory study (i.e. measuring at same time of day, appropriate hydration and food intake, etc.). Results from this study indicate that subjects with a PFO (PFO+) have a Tcore that is ~0.4°C higher at rest and during exercise than subjects without a PFO (PFO–). Additionally, this study showed that PFO– subjects do not increase Tcore to the same extent breathing cold air as they do breathing ambient air during a 10-minute exercise bout, whereas there was no difference in Tcore increase between these two conditions for PFO+ subjects. These findings suggest that the difference in Tcore between PFO+ and PFO– subjects is potentially due to differences in respiratory heat loss. The studies for Chapter V examined differences in thermoregulatory and ventilatory responses during hot water (40°C) and cold water (20°C) immersion. This study found that compared to PFO– subjects, PFO+ subjects 1) increase Tcore at the same rate during hot water immersion and 2) do not cool off as quickly during cold water immersion. Additionally, in subjects who reached a ventilatory threshold, PFO+ subjects had blunted ventilatory responses to increased Tcore compared to PFO– subjects. Finally, in Chapter VI it was shown that PFO+ subjects have blunted ventilatory responses during acute exposure to hyperoxic and normoxic hypercapnia. However, there were no differences in ventilatory responses between PFO+ and PFO– subjects during exposure to either isocapnic or poikilocapnic hypoxia. These findings suggest that PFO+ subjects have a blunted central chemoreflex. This dissertation contains previously, unpublished co-authored material. Title: Comprehensive examination of the differences in thermoregulatory and ventilatory responses between humans with and without a PFO under different environmental conditions Author: Davis, James Year: 2016 The existence of a patent foramen ovale (PFO) has been known about for nearly 2,000 years. The prevalence of a PFO has been shown to be 25-40% in the general population. Despite the fact that blood flowing through a PFO acts as a shunt, there has been little research looking at the effect a PFO has on physiology in otherwise healthy humans. In Chapter IV, the effect of a PFO on core temperature (Tcore) prior to, and during exercise, was investigated. The design of this experiment included appropriate controls for a thermoregulatory study (i.e. measuring at same time of day, appropriate hydration and food intake, etc.). Results from this study indicate that subjects with a PFO (PFO+) have a Tcore that is ~0.4°C higher at rest and during exercise than subjects without a PFO (PFO–). Additionally, this study showed that PFO– subjects do not increase Tcore to the same extent breathing cold air as they do breathing ambient air during a 10-minute exercise bout, whereas there was no difference in Tcore increase between these two conditions for PFO+ subjects. These findings suggest that the difference in Tcore between PFO+ and PFO– subjects is potentially due to differences in respiratory heat loss. The studies for Chapter V examined differences in thermoregulatory and ventilatory responses during hot water (40°C) and cold water (20°C) immersion. This study found that compared to PFO– subjects, PFO+ subjects 1) increase Tcore at the same rate during hot water immersion and 2) do not cool off as quickly during cold water immersion. Additionally, in subjects who reached a ventilatory threshold, PFO+ subjects had blunted ventilatory responses to increased Tcore compared to PFO– subjects. Finally, in Chapter VI it was shown that PFO+ subjects have blunted ventilatory responses during acute exposure to hyperoxic and normoxic hypercapnia. However, there were no differences in ventilatory responses between PFO+ and PFO– subjects during exposure to either isocapnic or poikilocapnic hypoxia. These findings suggest that PFO+ subjects have a blunted central chemoreflex. This dissertation contains previously, unpublished co-authored material. Close

• 272. [Article] Community assembly of benthic invertebrates on island-like marine hard substrata

  Most of the seafloor is soft sediment, so hard substrata are isolated and island-like. In this dissertation, I explore how species distribution patterns on isolated marine hard substrata resemble terrestrial ...

  Citation × Citation Citation Abstract Copy Title: Community assembly of benthic invertebrates on island-like marine hard substrata Author: Meyer, Kirstin Year: 2016 Most of the seafloor is soft sediment, so hard substrata are isolated and island-like. In this dissertation, I explore how species distribution patterns on isolated marine hard substrata resemble terrestrial island communities, drawing on classical island biogeography theory and assembly rules, and describe how benthic invertebrate communities assemble in these island-like habitats. Higher species richness occurred on larger substrata (dropstones and shipwrecks), paralleling terrestrial island communities. However, while larger islands have greater habitat diversity and primary productivity, marine hard substrata are simpler habitats. Greater elevation in the benthic boundary layer may expose fauna to faster current, higher food supply and larval flux. Substrata located closer together had more similar communities, another pattern that resembles terrestrial islands. Dropstone fauna had a clumped distribution, indicating that larvae may disperse among substrata located close together, resulting in similar communities. In Svalbard fjords, benthic megafaunal communities were significantly different between Arctic- and Atlantic-influenced fjords. Depth and temperature had the greatest influence, with the highest diversity occurring in cold Rijpfjorden and on the north Svalbard shelf. Recruitment in Svalbard fjords was spatially and temporally variable, with lower recruitment in Rijpfjorden than in Atlantic-influenced fjords and lower recruitment at greater depth. Most of the recruits in Svalbard fjords were fast-growing, poor-competitive opportunists. On shipwrecks, communities showed two mechanisms of colonization: mobile fauna with long-dispersing planktotrophic larvae, and encrusting fauna with lecithotrophic larvae. Encrusting species reproduce asexually to cover the wreck surface, and philopatry may build up dense populations, leading to uneven communities. On terrestrial islands, non-random co-occurrence is attributed to interspecific competition, but for marine substrata, there may not be a relationship. Fauna were distributed randomly on settlement plates in Svalbard fjords, even when interspecific competition was observed. On dropstones, some morphotypes co-occurred non-randomly in the absence of overgrowth competition. Non-random co-occurrence on isolated marine hard substrata may be a result of restricted larval dispersal (for pairs co-occurring less than by chance) or epibiontism (for pairs co-occurring more often than by chance). While species distribution patterns on island-like marine hard substrata resemble terrestrial islands, the mechanisms are not necessarily the same. Title: Community assembly of benthic invertebrates on island-like marine hard substrata Author: Meyer, Kirstin Year: 2016 Most of the seafloor is soft sediment, so hard substrata are isolated and island-like. In this dissertation, I explore how species distribution patterns on isolated marine hard substrata resemble terrestrial island communities, drawing on classical island biogeography theory and assembly rules, and describe how benthic invertebrate communities assemble in these island-like habitats. Higher species richness occurred on larger substrata (dropstones and shipwrecks), paralleling terrestrial island communities. However, while larger islands have greater habitat diversity and primary productivity, marine hard substrata are simpler habitats. Greater elevation in the benthic boundary layer may expose fauna to faster current, higher food supply and larval flux. Substrata located closer together had more similar communities, another pattern that resembles terrestrial islands. Dropstone fauna had a clumped distribution, indicating that larvae may disperse among substrata located close together, resulting in similar communities. In Svalbard fjords, benthic megafaunal communities were significantly different between Arctic- and Atlantic-influenced fjords. Depth and temperature had the greatest influence, with the highest diversity occurring in cold Rijpfjorden and on the north Svalbard shelf. Recruitment in Svalbard fjords was spatially and temporally variable, with lower recruitment in Rijpfjorden than in Atlantic-influenced fjords and lower recruitment at greater depth. Most of the recruits in Svalbard fjords were fast-growing, poor-competitive opportunists. On shipwrecks, communities showed two mechanisms of colonization: mobile fauna with long-dispersing planktotrophic larvae, and encrusting fauna with lecithotrophic larvae. Encrusting species reproduce asexually to cover the wreck surface, and philopatry may build up dense populations, leading to uneven communities. On terrestrial islands, non-random co-occurrence is attributed to interspecific competition, but for marine substrata, there may not be a relationship. Fauna were distributed randomly on settlement plates in Svalbard fjords, even when interspecific competition was observed. On dropstones, some morphotypes co-occurred non-randomly in the absence of overgrowth competition. Non-random co-occurrence on isolated marine hard substrata may be a result of restricted larval dispersal (for pairs co-occurring less than by chance) or epibiontism (for pairs co-occurring more often than by chance). While species distribution patterns on island-like marine hard substrata resemble terrestrial islands, the mechanisms are not necessarily the same. Close

• 273. [Article] NITRIC OXIDE SIGNALLING PATHWAYS FOLLOWING CHRONIC PASSIVE HEAT THERAPY

  64 pages. A thesis presented to the Department of Human Physiology and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Science, ...

  Citation × Citation Citation Abstract Copy Title: NITRIC OXIDE SIGNALLING PATHWAYS FOLLOWING CHRONIC PASSIVE HEAT THERAPY Author: Eymann, Taylor Year: 2016 64 pages. A thesis presented to the Department of Human Physiology and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Science, Spring 2016. Title: NITRIC OXIDE SIGNALLING PATHWAYS FOLLOWING CHRONIC PASSIVE HEAT THERAPY Author: Eymann, Taylor Year: 2016 64 pages. A thesis presented to the Department of Human Physiology and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Science, Spring 2016. Close

• 274. [Article] Modeling Circulation Dynamics and Submarine Melt in Greenland Fjords

  Meltwater accumulated on the Greenland Ice Sheet drains to glacier beds, discharging into fjords hundreds of meters below sea level. The injection of meltwater at depth generates an upwelling plume that ...

  Citation × Citation Citation Abstract Copy Title: Modeling Circulation Dynamics and Submarine Melt in Greenland Fjords Author: Carroll, Dustin Year: 2017 Meltwater accumulated on the Greenland Ice Sheet drains to glacier beds, discharging into fjords hundreds of meters below sea level. The injection of meltwater at depth generates an upwelling plume that entrains warm ocean water as it rises along the terminus, increasing submarine melt and driving a fjord-scale exchange flow. However, due to sparse ocean-glacier observations, we lack a process understanding of how plumes control fjord circulation and submarine melt. Combining numerical modeling, theory, and observations, this dissertation investigates near-glacier plume dynamics, the influence of glacier depth on plume structure and submarine melt, and the role of fjord-glacier geometry on circulation in tidewater glacier fjords. In Chapter II, I use buoyant plume theory and a nonhydrostatic, three-dimensional ocean–ice model to investigate the sensitivity of plume dynamics to subglacial discharge, turbulent diffusivity, and conduit geometry. Large discharges result in plumes with positive temperature and salinity anomalies in the upper water column. Fjord circulation is sensitive to conduit geometry; distributed subglacial discharge results in a stronger return flow of warm water toward the terminus. In Chapter III, I use buoyant plume theory, initialized with realistic ranges of subglacial discharge, glacier depth, and ocean stratification, to investigate how plume structure and submarine melt vary during summer months in 12 Greenland fjords. Grounding line depth is a primary control on plume-induced submarine melt: deep glaciers produce warm, salty subsurface plumes that undercut termini, and shallow glaciers produce cold, fresh surface-confined plumes that can overcut. Finally, in Chapter IV, I use regional-scale numerical ocean simulations to systematically evaluate how fjord circulation forced by subglacial plumes, tides, and wind stress depends on fjord width, glacier depth, and sill height. Glaciers grounded below sill depth can draw shelf waters over a shallow sill and into fjord basins with seasonal subglacial discharge; this process is independent of external shelf forcing. These results underscore the first-order effect that subglacial discharge and fjord-glacier geometry have in controlling fjord circulation and, thus, ocean heat flux to the ice. This dissertation includes previously published and co-authored material. Title: Modeling Circulation Dynamics and Submarine Melt in Greenland Fjords Author: Carroll, Dustin Year: 2017 Meltwater accumulated on the Greenland Ice Sheet drains to glacier beds, discharging into fjords hundreds of meters below sea level. The injection of meltwater at depth generates an upwelling plume that entrains warm ocean water as it rises along the terminus, increasing submarine melt and driving a fjord-scale exchange flow. However, due to sparse ocean-glacier observations, we lack a process understanding of how plumes control fjord circulation and submarine melt. Combining numerical modeling, theory, and observations, this dissertation investigates near-glacier plume dynamics, the influence of glacier depth on plume structure and submarine melt, and the role of fjord-glacier geometry on circulation in tidewater glacier fjords. In Chapter II, I use buoyant plume theory and a nonhydrostatic, three-dimensional ocean–ice model to investigate the sensitivity of plume dynamics to subglacial discharge, turbulent diffusivity, and conduit geometry. Large discharges result in plumes with positive temperature and salinity anomalies in the upper water column. Fjord circulation is sensitive to conduit geometry; distributed subglacial discharge results in a stronger return flow of warm water toward the terminus. In Chapter III, I use buoyant plume theory, initialized with realistic ranges of subglacial discharge, glacier depth, and ocean stratification, to investigate how plume structure and submarine melt vary during summer months in 12 Greenland fjords. Grounding line depth is a primary control on plume-induced submarine melt: deep glaciers produce warm, salty subsurface plumes that undercut termini, and shallow glaciers produce cold, fresh surface-confined plumes that can overcut. Finally, in Chapter IV, I use regional-scale numerical ocean simulations to systematically evaluate how fjord circulation forced by subglacial plumes, tides, and wind stress depends on fjord width, glacier depth, and sill height. Glaciers grounded below sill depth can draw shelf waters over a shallow sill and into fjord basins with seasonal subglacial discharge; this process is independent of external shelf forcing. These results underscore the first-order effect that subglacial discharge and fjord-glacier geometry have in controlling fjord circulation and, thus, ocean heat flux to the ice. This dissertation includes previously published and co-authored material. Close

• 275. [Article] SURPRISING PROPERTIES OF STATIC AND FLOWING GRANULAR MATTER

  The Janssen effect is a unique property of confined granular materials experiencing gravitational compaction in which the pressure at the bottom saturates with increasing filling height due to frictional ...

  Citation × Citation Citation Abstract Copy Title: SURPRISING PROPERTIES OF STATIC AND FLOWING GRANULAR MATTER Author: Karim, Mohammad Year: 2017 The Janssen effect is a unique property of confined granular materials experiencing gravitational compaction in which the pressure at the bottom saturates with increasing filling height due to frictional interactions with side walls. In this paper we replace gravitational compaction with frictional compaction. We study friction-compacted 2D granular materials confined within fixed boundaries on a horizontal conveyor belt. We find that even with high friction side walls the Janssen effect completely vanishes. Our results demonstrate that gravity-compacted granular systems are inherently different from friction-compacted systems in at least one important way: vibrations induced by sliding friction with the driving surface relax away tangential forces on the walls. Remarkably, we find that the Janssen effect can be recovered by replacing the straight side walls with a sawtooth pattern. The mechanical force introduced by varying the sawtooth angle $\theta$ can be viewed as equivalent to a tunable friction force. By construction, this mechanical friction force cannot be relaxed away by vibrations in the system. This work is described in Chapter 2 and has been published in \textit{Physical Review Letters}. We experimentally study quasi-2d dilute granular flow around intruders whose shape, size and relative impact speed are systematically varied. Direct measurement of the flow field reveals that three in-principle independent measurements of the non-uniformity of the flow field are in fact all linearly related: 1) granular temperature, 2) flow field divergence and 3) shear-strain rate. The shock front is defined as the local maxima in each of these measurements. The shape of the shock front is well described by an inverted catenary and is driven by the formation of a dynamic arch during steady flow. We find universality in the functional form of the shock front within the range of experimental values probed. Changing the intruder size, concavity and impact speed only results in a scaling and shifting of the shock front. We independently measure the horizontal lift force on the intruder and find that it can be understood as a result of the interplay between the shock profile and the intruder shape. This work is described in Chapter 3. This dissertation includes previously published and unpublished co-authored material. Title: SURPRISING PROPERTIES OF STATIC AND FLOWING GRANULAR MATTER Author: Karim, Mohammad Year: 2017 The Janssen effect is a unique property of confined granular materials experiencing gravitational compaction in which the pressure at the bottom saturates with increasing filling height due to frictional interactions with side walls. In this paper we replace gravitational compaction with frictional compaction. We study friction-compacted 2D granular materials confined within fixed boundaries on a horizontal conveyor belt. We find that even with high friction side walls the Janssen effect completely vanishes. Our results demonstrate that gravity-compacted granular systems are inherently different from friction-compacted systems in at least one important way: vibrations induced by sliding friction with the driving surface relax away tangential forces on the walls. Remarkably, we find that the Janssen effect can be recovered by replacing the straight side walls with a sawtooth pattern. The mechanical force introduced by varying the sawtooth angle $\theta$ can be viewed as equivalent to a tunable friction force. By construction, this mechanical friction force cannot be relaxed away by vibrations in the system. This work is described in Chapter 2 and has been published in \textit{Physical Review Letters}. We experimentally study quasi-2d dilute granular flow around intruders whose shape, size and relative impact speed are systematically varied. Direct measurement of the flow field reveals that three in-principle independent measurements of the non-uniformity of the flow field are in fact all linearly related: 1) granular temperature, 2) flow field divergence and 3) shear-strain rate. The shock front is defined as the local maxima in each of these measurements. The shape of the shock front is well described by an inverted catenary and is driven by the formation of a dynamic arch during steady flow. We find universality in the functional form of the shock front within the range of experimental values probed. Changing the intruder size, concavity and impact speed only results in a scaling and shifting of the shock front. We independently measure the horizontal lift force on the intruder and find that it can be understood as a result of the interplay between the shock profile and the intruder shape. This work is described in Chapter 3. This dissertation includes previously published and unpublished co-authored material. Close

• 276. [Article] Electron Transport Dynamics in Semiconductor Heterostructure Devices

  Modern semiconductor fabrication techniques allow for the fabrication of semiconductor heterostructures which host electron transport with a minimum of scattering sites. In such devices, electrons populate ...

  Citation × Citation Citation Abstract Copy Title: Electron Transport Dynamics in Semiconductor Heterostructure Devices Author: Pilgrim, Ian Year: 2014 Modern semiconductor fabrication techniques allow for the fabrication of semiconductor heterostructures which host electron transport with a minimum of scattering sites. In such devices, electrons populate a two-dimensional electron gas (2DEG) in which electrons propagate in exactly two dimensions, and may be further confined by potential barriers to form electron billiards. At sub-Kelvin temperatures, electron trajectories are determined largely by reflections from the billiard walls, while net conduction through the device depends on quantum mechanical wave interference. Measurements of magnetoconductance fluctuations (MCF) serve as a probe of dynamics within the electron billiard. Many prior studies have utilized heterostructures employing the modulation doping architecture, in which the 2DEG is spatially removed from the donor atoms to minimize electron scattering. Theoretical studies have claimed that MCF will be fractal when the confinement potential defining the billiard is soft-walled, regardless of the presence of smooth potentials within the billiard such as those introduced by remote ionized donors. The small-angle scattering sites resulting from these potentials are often disregarded as negligible; we use MCF measurements to investigate such claims. To probe the effect of remote ionized donor scattering on the phase space in electron billiards, we compare MCF measured on billiards in a modulation-doped heterostructure to those measured on billiards in an undoped heterostructure, in which this potential landscape is believed to be absent. Fractal studies are performed on these MCF traces, and we find that MCF measured on the undoped billiards do not exhibit measurably different fractal characteristics than those measured on the modulation-doped billiards. Having confirmed that the potential landscapes in modulation-doped heterostructures do not affect the electron phase space, we then investigate the effect of these impurities on the distribution of electron trajectories through the billiards. By employing thermal cycling experiments, we demonstrate that this distribution is highly sensitive to the precise potential landscape within the billiard, suggesting that modulation-doped heterostructures do not support fully ballistic electron transport. We compare our MCF correlation data with the dynamics of charge transfer within heterostructure systems to make qualitative conclusions regarding these dynamics. Title: Electron Transport Dynamics in Semiconductor Heterostructure Devices Author: Pilgrim, Ian Year: 2014 Modern semiconductor fabrication techniques allow for the fabrication of semiconductor heterostructures which host electron transport with a minimum of scattering sites. In such devices, electrons populate a two-dimensional electron gas (2DEG) in which electrons propagate in exactly two dimensions, and may be further confined by potential barriers to form electron billiards. At sub-Kelvin temperatures, electron trajectories are determined largely by reflections from the billiard walls, while net conduction through the device depends on quantum mechanical wave interference. Measurements of magnetoconductance fluctuations (MCF) serve as a probe of dynamics within the electron billiard. Many prior studies have utilized heterostructures employing the modulation doping architecture, in which the 2DEG is spatially removed from the donor atoms to minimize electron scattering. Theoretical studies have claimed that MCF will be fractal when the confinement potential defining the billiard is soft-walled, regardless of the presence of smooth potentials within the billiard such as those introduced by remote ionized donors. The small-angle scattering sites resulting from these potentials are often disregarded as negligible; we use MCF measurements to investigate such claims. To probe the effect of remote ionized donor scattering on the phase space in electron billiards, we compare MCF measured on billiards in a modulation-doped heterostructure to those measured on billiards in an undoped heterostructure, in which this potential landscape is believed to be absent. Fractal studies are performed on these MCF traces, and we find that MCF measured on the undoped billiards do not exhibit measurably different fractal characteristics than those measured on the modulation-doped billiards. Having confirmed that the potential landscapes in modulation-doped heterostructures do not affect the electron phase space, we then investigate the effect of these impurities on the distribution of electron trajectories through the billiards. By employing thermal cycling experiments, we demonstrate that this distribution is highly sensitive to the precise potential landscape within the billiard, suggesting that modulation-doped heterostructures do not support fully ballistic electron transport. We compare our MCF correlation data with the dynamics of charge transfer within heterostructure systems to make qualitative conclusions regarding these dynamics. Close

• 277. [Article] NANOARCHITECTURE-PROPERTY RELATIONSHIPS IN TISE2 BASED NANOLAMINATES FOR DEVELOPMENT OF NOVEL DESIGN STRATEGIES IN COMPOSITE THERMOELECTRIC MATERIALS

  This dissertation is centered on investigation of metastable thermoelectric thin film materials and is split into 3 primary sections. Section 1 focuses on formation mechanisms of FeSbx compounds from layered ...

  Citation × Citation Citation Abstract Copy Title: NANOARCHITECTURE-PROPERTY RELATIONSHIPS IN TISE2 BASED NANOLAMINATES FOR DEVELOPMENT OF NOVEL DESIGN STRATEGIES IN COMPOSITE THERMOELECTRIC MATERIALS Author: Bauers, Sage Year: 2017 This dissertation is centered on investigation of metastable thermoelectric thin film materials and is split into 3 primary sections. Section 1 focuses on formation mechanisms of FeSbx compounds from layered precursors. It was found that a compositionally favorable and homogeneous nucleation environment allowed for the nucleation of a metastable phase, which surprisingly resembles the local coordination environment of the precursors, even in cases where they are compositionally unfavorable. Over the course of this work, the technique of normal-incidence thin film pair distribution function analysis is introduced, which allows for rapid acquisition and analysis of local structure data from intact thin films. Section 2 investigates changes in the stacking sequences of ([PbSe]1+δ)m(TiSe2)n nanolaminate materials, which consist of interleaved layers of each compound in the chemical formula, and how these changes effect the thermoelectric power factor. Homologous series of systematically varying m and n values are investigated and measured properties are correlated back to the designed nanoarchitecture of the laminate materials. It is found that the compounds are stabilized by electron exchange between constituents at the interfaces, and that ‘doping’ of the laminate structure by changing the relative amounts of each constituent is an effective means of optimizing their transport properties. It is also shown that interface density between constituents can be utilized to optimize performance. Section 3 moves from the case of PbSe layers, which maintain their structure, to SnSe layers that significantly distort as the layer size is changed. The distortions in SnSe are observed to occur from templating off TiSe2 layers. As the size of the SnSe layers increases, relatively fewer templated interfacial atoms exist and stabilization of interior atoms must also be considered. The coarse behaviors developed in ([PbSe]1+δ)m(TiSe2)n hold, but the structural distortions in SnSe likely change the band structure of this constituent and hence the composite material, complicating the analysis. In some cases, these changes allow for radically different behavior, best exemplified with high TiSe2 ratios in ([SnSe]1+δ)1(TiSe2)n displaying significant enhancement of the Seebeck coefficient at cryogenic temperatures over the low-n and PbSe-containing analogues. This dissertation includes previously published and unpublished coauthored material. Title: NANOARCHITECTURE-PROPERTY RELATIONSHIPS IN TISE2 BASED NANOLAMINATES FOR DEVELOPMENT OF NOVEL DESIGN STRATEGIES IN COMPOSITE THERMOELECTRIC MATERIALS Author: Bauers, Sage Year: 2017 This dissertation is centered on investigation of metastable thermoelectric thin film materials and is split into 3 primary sections. Section 1 focuses on formation mechanisms of FeSbx compounds from layered precursors. It was found that a compositionally favorable and homogeneous nucleation environment allowed for the nucleation of a metastable phase, which surprisingly resembles the local coordination environment of the precursors, even in cases where they are compositionally unfavorable. Over the course of this work, the technique of normal-incidence thin film pair distribution function analysis is introduced, which allows for rapid acquisition and analysis of local structure data from intact thin films. Section 2 investigates changes in the stacking sequences of ([PbSe]1+δ)m(TiSe2)n nanolaminate materials, which consist of interleaved layers of each compound in the chemical formula, and how these changes effect the thermoelectric power factor. Homologous series of systematically varying m and n values are investigated and measured properties are correlated back to the designed nanoarchitecture of the laminate materials. It is found that the compounds are stabilized by electron exchange between constituents at the interfaces, and that ‘doping’ of the laminate structure by changing the relative amounts of each constituent is an effective means of optimizing their transport properties. It is also shown that interface density between constituents can be utilized to optimize performance. Section 3 moves from the case of PbSe layers, which maintain their structure, to SnSe layers that significantly distort as the layer size is changed. The distortions in SnSe are observed to occur from templating off TiSe2 layers. As the size of the SnSe layers increases, relatively fewer templated interfacial atoms exist and stabilization of interior atoms must also be considered. The coarse behaviors developed in ([PbSe]1+δ)m(TiSe2)n hold, but the structural distortions in SnSe likely change the band structure of this constituent and hence the composite material, complicating the analysis. In some cases, these changes allow for radically different behavior, best exemplified with high TiSe2 ratios in ([SnSe]1+δ)1(TiSe2)n displaying significant enhancement of the Seebeck coefficient at cryogenic temperatures over the low-n and PbSe-containing analogues. This dissertation includes previously published and unpublished coauthored material. Close

• 278. [Article] Circuit and Behavioral Analysis of Klinotaxis in Caenorhabditis elegans

  The nervous system is a complex organ that functions in most metazoans to sense and respond to a constantly changing world. How the nervous system does this is a major focus of systems-level neuroscience. ...

  Citation × Citation Citation Abstract Copy Title: Circuit and Behavioral Analysis of Klinotaxis in Caenorhabditis elegans Author: McCormick, Kathryn Year: 2013, 2014 The nervous system is a complex organ that functions in most metazoans to sense and respond to a constantly changing world. How the nervous system does this is a major focus of systems-level neuroscience. This dissertation investigates the neural basis of the sensorimotor transformation underlying a spatial orientation strategy in the nematode Caenorhabditis elegans. Motile organisms rely on spatial orientation strategies to navigate to environments that are conducive to organismal fitness and comfort, e.g. environments with the correct temperature, light level, or access to food and mates. As such, spatial orientation strategies as a class represent a key behavior common to most forms of life on earth. To explore the behavioral mechanism used by C. elegans for spatial orientation, we designed and manufactured a microfluidic device that breaks the feedback loop between self-motion and environmental change by partially restraining the animal. The device takes advantage of laminar flow at small scale to provide distinct environments across the dorsoventral undulation that constitutes locomotion in this animal without using a physical barrier. This device allowed us to conclude that worms use the change in chemical concentration sensed between lateral extremes of the locomotion cycle to direct forward locomotion toward a favorable stimulus, an orientation strategy termed klinotaxis. We then investigated the neuronal basis of this behavior using laser ablation, calcium imaging, and optogenetic stimulation. We found a minimal neuronal network for klinotaxis to sodium chloride including the ASE, AIY, AIZ, and SMB neuron classes that displays left/right asymmetry across the sensory neuron, interneuron, and motor neuron levels. We extended these results by ablating other neurons that have been implicated in klinotaxis in other studies. Finally, we imaged the ASE neurons during klinotaxis in microfluidic device and found that these neurons are active on the timescale of individual head swings. Additionally, we found anecdotal evidence that photostimulation of ASE neurons expressing the light sensitive ion channel Channel Rhodopsin (CHR2) is sufficient to stimulate klinotaxis behavior. This dissertation includes previously published co-authored material. Title: Circuit and Behavioral Analysis of Klinotaxis in Caenorhabditis elegans Author: McCormick, Kathryn Year: 2013, 2014 The nervous system is a complex organ that functions in most metazoans to sense and respond to a constantly changing world. How the nervous system does this is a major focus of systems-level neuroscience. This dissertation investigates the neural basis of the sensorimotor transformation underlying a spatial orientation strategy in the nematode Caenorhabditis elegans. Motile organisms rely on spatial orientation strategies to navigate to environments that are conducive to organismal fitness and comfort, e.g. environments with the correct temperature, light level, or access to food and mates. As such, spatial orientation strategies as a class represent a key behavior common to most forms of life on earth. To explore the behavioral mechanism used by C. elegans for spatial orientation, we designed and manufactured a microfluidic device that breaks the feedback loop between self-motion and environmental change by partially restraining the animal. The device takes advantage of laminar flow at small scale to provide distinct environments across the dorsoventral undulation that constitutes locomotion in this animal without using a physical barrier. This device allowed us to conclude that worms use the change in chemical concentration sensed between lateral extremes of the locomotion cycle to direct forward locomotion toward a favorable stimulus, an orientation strategy termed klinotaxis. We then investigated the neuronal basis of this behavior using laser ablation, calcium imaging, and optogenetic stimulation. We found a minimal neuronal network for klinotaxis to sodium chloride including the ASE, AIY, AIZ, and SMB neuron classes that displays left/right asymmetry across the sensory neuron, interneuron, and motor neuron levels. We extended these results by ablating other neurons that have been implicated in klinotaxis in other studies. Finally, we imaged the ASE neurons during klinotaxis in microfluidic device and found that these neurons are active on the timescale of individual head swings. Additionally, we found anecdotal evidence that photostimulation of ASE neurons expressing the light sensitive ion channel Channel Rhodopsin (CHR2) is sufficient to stimulate klinotaxis behavior. This dissertation includes previously published co-authored material. Close

• 279. [Article] Defining the Terroir of the Columbia Gorge Wine Region, Oregon and Washington, USA Using Geographic Information Systems (GIS)

  The Columbia Gorge Wine Region (CGWR) is an emerging wine producing area that extends for about 100km along the Columbia River in Oregon and Washington State in which the number of vineyards, wineries ...

  Citation × Citation Citation Abstract Copy Title: Defining the Terroir of the Columbia Gorge Wine Region, Oregon and Washington, USA Using Geographic Information Systems (GIS) Author: Whitney, Hilary Year: 2015 The Columbia Gorge Wine Region (CGWR) is an emerging wine producing area that extends for about 100km along the Columbia River in Oregon and Washington State in which the number of vineyards, wineries and physical terroir conditions have yet to be defined. To better understand the physical factors affecting Oregon and Washington wine, this project analyzes climate, topography, geology and soil at vineyards in the CGWR. This was accomplished using Geographic Information Systems, existing earth science databases and field work. The region, which includes the Columbia Gorge American Viticulture Area (AVA) and the southwest portion of the Columbia Valley AVA, is home to 82 vineyards, 513 hectares (1268 acres), 37 wineries and 41 different varieties of Vitus Vinifera. Vineyards range in elevation from 29 to 548 meters (95 to 1799 feet). Vintner responses to a grower's survey suggest that twenty-eight grape varieties account for 98% of the estimated grape variety acreage, with Pinot Noir being the most widely planted grape variety in both AVAs. The boundaries of each climatic regime were mapped based on 1981-2010 PRISM data, the Winkler Index (Amerine and Winkler, 1944) updated by Jones et al. (2010) and climatic maturity groupings designed for Oregon (Jones et al., 2002; Jones et al., 2010). Three Winkler climate regimes are represented within the CGWR, including regions Ia, Ib, and II from the Winkler Index (Jones et al., 2010). The diversity in regimes allows for a diversity of grape varieties to be planted within the regime. The average growing season temperatures and growing degree days, respectively, from 1981-2010 calculated for vineyards ranges from 13.7°C (55.7°F) to 17.7°C (63.9°F) and 871 for °C (1567 for °F) to 1664 for °C (2994 for °F) respectively. 58% of the vineyards are characterized in an intermediate climatic regime, 29% are within a cool climatic regime, 9% are within a warm climatic regime and 4% are on the boundaries between a cool, intermediate or warm regime. 80% of the vineyards are within Regions Ia and Ib characterized by the Winkler Index, and 20% are within Region II. The growing degrees days calculated for the CGWR are similar those measured in the Willamette Valley, Oregon, Burgundy, France, Umpqua Valley AVA in Oregon and Bordeaux wine region in France. All of the soils currently being used to grow grapes are well-drained and within a xeric moisture regime, which are favorable conditions for viticulture. 30 soil series are represented among the vineyard sites, with the Chemawa Series (Underwood Mountain) and Walla Walla Series (eastern portions) being the dominant soil series used to grow grapes. Majority of the soils contain a silt loam texture. Soil Survey data for Oregon and Washington suggest that loess is extensive in the CGWR, with 46.5% of the total vineyard acreage planted on soils formed in loess. The Missoula Floods also greatly influenced the texture and age of the soil in this region, with skeletal textures being close to the Columbia River. Other common geological deposits at vineyards in the CGWR include, Quaternary Basalt (19.6%), Missoula Flood deposits (9.1%), The Dalles Formation (8.0%), Columbia River Basalt Group (7.5%), Pliocene Basalt (3.0%), Quaternary Surficial deposits (3.0%), lahars (2.3%) and Quaternary Basaltic Andesite and Andesite (0.9%). Common geological deposits, soil series, and climate conditions at vineyard sites vary spatially in the region, and therefore it is suggested that future work focus on separating the region into separate climatic sub-AVA regimes to better reflect the diversity in terroir conditions. Title: Defining the Terroir of the Columbia Gorge Wine Region, Oregon and Washington, USA Using Geographic Information Systems (GIS) Author: Whitney, Hilary Year: 2015 The Columbia Gorge Wine Region (CGWR) is an emerging wine producing area that extends for about 100km along the Columbia River in Oregon and Washington State in which the number of vineyards, wineries and physical terroir conditions have yet to be defined. To better understand the physical factors affecting Oregon and Washington wine, this project analyzes climate, topography, geology and soil at vineyards in the CGWR. This was accomplished using Geographic Information Systems, existing earth science databases and field work. The region, which includes the Columbia Gorge American Viticulture Area (AVA) and the southwest portion of the Columbia Valley AVA, is home to 82 vineyards, 513 hectares (1268 acres), 37 wineries and 41 different varieties of Vitus Vinifera. Vineyards range in elevation from 29 to 548 meters (95 to 1799 feet). Vintner responses to a grower's survey suggest that twenty-eight grape varieties account for 98% of the estimated grape variety acreage, with Pinot Noir being the most widely planted grape variety in both AVAs. The boundaries of each climatic regime were mapped based on 1981-2010 PRISM data, the Winkler Index (Amerine and Winkler, 1944) updated by Jones et al. (2010) and climatic maturity groupings designed for Oregon (Jones et al., 2002; Jones et al., 2010). Three Winkler climate regimes are represented within the CGWR, including regions Ia, Ib, and II from the Winkler Index (Jones et al., 2010). The diversity in regimes allows for a diversity of grape varieties to be planted within the regime. The average growing season temperatures and growing degree days, respectively, from 1981-2010 calculated for vineyards ranges from 13.7°C (55.7°F) to 17.7°C (63.9°F) and 871 for °C (1567 for °F) to 1664 for °C (2994 for °F) respectively. 58% of the vineyards are characterized in an intermediate climatic regime, 29% are within a cool climatic regime, 9% are within a warm climatic regime and 4% are on the boundaries between a cool, intermediate or warm regime. 80% of the vineyards are within Regions Ia and Ib characterized by the Winkler Index, and 20% are within Region II. The growing degrees days calculated for the CGWR are similar those measured in the Willamette Valley, Oregon, Burgundy, France, Umpqua Valley AVA in Oregon and Bordeaux wine region in France. All of the soils currently being used to grow grapes are well-drained and within a xeric moisture regime, which are favorable conditions for viticulture. 30 soil series are represented among the vineyard sites, with the Chemawa Series (Underwood Mountain) and Walla Walla Series (eastern portions) being the dominant soil series used to grow grapes. Majority of the soils contain a silt loam texture. Soil Survey data for Oregon and Washington suggest that loess is extensive in the CGWR, with 46.5% of the total vineyard acreage planted on soils formed in loess. The Missoula Floods also greatly influenced the texture and age of the soil in this region, with skeletal textures being close to the Columbia River. Other common geological deposits at vineyards in the CGWR include, Quaternary Basalt (19.6%), Missoula Flood deposits (9.1%), The Dalles Formation (8.0%), Columbia River Basalt Group (7.5%), Pliocene Basalt (3.0%), Quaternary Surficial deposits (3.0%), lahars (2.3%) and Quaternary Basaltic Andesite and Andesite (0.9%). Common geological deposits, soil series, and climate conditions at vineyard sites vary spatially in the region, and therefore it is suggested that future work focus on separating the region into separate climatic sub-AVA regimes to better reflect the diversity in terroir conditions. Close

• 280. [Article] Water Purification Technologies: From a Residential Scale Perspective

  The Problem: Small communities in many parts of the world do not have fresh water, especially after natural disasters. Many Puerto Rico local governments did not investigate and maintain local water purification ...

  Citation × Citation Citation Abstract Copy Title: Water Purification Technologies: From a Residential Scale Perspective Author: Nguyen, Tin, Owaishiz, Abdalilah, Ryan, Mark Year: 2017 The Problem: Small communities in many parts of the world do not have fresh water, especially after natural disasters. Many Puerto Rico local governments did not investigate and maintain local water purification and pipe systems or possible superfund sites in preparation of natural disasters because they do not have enough staff due to Territory and EPA budget cuts. Local governments in Puerto Rico need to continue to react quickly because a majority of regional communities who have had community water service have not been able to restore their water systems. According to Vox, “there have also been reports of water contaminated raw sewage and at least 74 suspected cases and two deaths from leptospirosis, a deadly animal-borne disease that can also live in water” [31]. If people in Puerto Rico keep drinking water from dirty water pump systems due to the shortage of drinking water many more people in Puerto Rico can become seriously ill and may lead to death. Local governments in Puerto Rico need to reach out to the EPA and CDCP to provide effective strategies of water purification and help citizens by providing clean water technology to examine water that contains virus and contamination. The United States government needs to collaborate with Puerto Rico to resolve the environment issues occurring. According to Vox, “there are 18 superfund sites in Puerto Rico, including the Dorado Groundwater Contamination Site in the north-central part of the island where some people were getting their water. The site is part of a drinking water system that serves 67,000 people” [31]. According to Peter Lopez, the newly appointed head of EPA Region II, “From my experience, communities that are struggling financially are going to be hardest pressed to respond” [31]. This is a challenge when local governments do not receive help from FEMA to have funding for the healthcare fund, superfund site investigation, maintenance of pump systems, and delivery cost for thousands of bottles of water to reach Puerto Ricans hands. People have to use this unsafe water and they try to boil it but the taste is unacceptable. According to Oren and Atabey for USA today, Ortiz worries that the bad-tasting, blue-colored water that runs in her pipes is unsafe. She and her aunt use it only to clean clothes and dishes, and to shower. They had tried boiling it, but “it tasted weird,” Ortiz said. Bottled water can be hard to find and gets expensive, said her aunt, Maria Ortiz, 66. “If you are lucky to find some, a pack of 24 water bottles that used to be $3.99 now is about $7.50,” she said [32]. More and more Puerto Ricans are having a shortage of water delivered to them due to the lack of staffing. Our Focus: Evaluate water purification technologies in communities (at the residential level) of Puerto Rico and other Island Nations which have recently been devastated by hurricanes and are suffering greatly from lack of fresh water. Introduction: Less than 1% of the water on this planet is fresh water suitable for human use and most of that is inaccessible being frozen in polar ice caps. Climate change furthers this discrepancy when global temperatures rise. Climate becomes more radical increasing climatic extremes and causing more natural disasters. Contamination is a great risk to our water; especially surface water where pathogenic bacteria and microbes flourish and dissolved dirt can make it turbid. This is a problem on a massive global scale, but locally it is not challenging to solve. Providing clean water and educating people locally at the residential level is relatively easy. Title: Water Purification Technologies: From a Residential Scale Perspective Author: Nguyen, Tin, Owaishiz, Abdalilah, Ryan, Mark Year: 2017 The Problem: Small communities in many parts of the world do not have fresh water, especially after natural disasters. Many Puerto Rico local governments did not investigate and maintain local water purification and pipe systems or possible superfund sites in preparation of natural disasters because they do not have enough staff due to Territory and EPA budget cuts. Local governments in Puerto Rico need to continue to react quickly because a majority of regional communities who have had community water service have not been able to restore their water systems. According to Vox, “there have also been reports of water contaminated raw sewage and at least 74 suspected cases and two deaths from leptospirosis, a deadly animal-borne disease that can also live in water” [31]. If people in Puerto Rico keep drinking water from dirty water pump systems due to the shortage of drinking water many more people in Puerto Rico can become seriously ill and may lead to death. Local governments in Puerto Rico need to reach out to the EPA and CDCP to provide effective strategies of water purification and help citizens by providing clean water technology to examine water that contains virus and contamination. The United States government needs to collaborate with Puerto Rico to resolve the environment issues occurring. According to Vox, “there are 18 superfund sites in Puerto Rico, including the Dorado Groundwater Contamination Site in the north-central part of the island where some people were getting their water. The site is part of a drinking water system that serves 67,000 people” [31]. According to Peter Lopez, the newly appointed head of EPA Region II, “From my experience, communities that are struggling financially are going to be hardest pressed to respond” [31]. This is a challenge when local governments do not receive help from FEMA to have funding for the healthcare fund, superfund site investigation, maintenance of pump systems, and delivery cost for thousands of bottles of water to reach Puerto Ricans hands. People have to use this unsafe water and they try to boil it but the taste is unacceptable. According to Oren and Atabey for USA today, Ortiz worries that the bad-tasting, blue-colored water that runs in her pipes is unsafe. She and her aunt use it only to clean clothes and dishes, and to shower. They had tried boiling it, but “it tasted weird,” Ortiz said. Bottled water can be hard to find and gets expensive, said her aunt, Maria Ortiz, 66. “If you are lucky to find some, a pack of 24 water bottles that used to be $3.99 now is about $7.50,” she said [32]. More and more Puerto Ricans are having a shortage of water delivered to them due to the lack of staffing. Our Focus: Evaluate water purification technologies in communities (at the residential level) of Puerto Rico and other Island Nations which have recently been devastated by hurricanes and are suffering greatly from lack of fresh water. Introduction: Less than 1% of the water on this planet is fresh water suitable for human use and most of that is inaccessible being frozen in polar ice caps. Climate change furthers this discrepancy when global temperatures rise. Climate becomes more radical increasing climatic extremes and causing more natural disasters. Contamination is a great risk to our water; especially surface water where pathogenic bacteria and microbes flourish and dissolved dirt can make it turbid. This is a problem on a massive global scale, but locally it is not challenging to solve. Providing clean water and educating people locally at the residential level is relatively easy. Close