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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
161

Fluorescent probes of conformational signal relay in membrane environments

Lister, Francis George Alexander January 2015 (has links)
G-Protein Coupled Receptors (GPCRs) are a class of membrane-bound receptor proteins capable of relaying a biological signal across a cell membrane through a solely conformational change in their transmembrane domain. Previous work has shown that helical foldamers composed of achiral monomeric units can be used in an analogous manner to relay stereochemical information on the nano-scale through the conformational control of screw-sense preference. While this work has produced some highly successful examples of signal relay, mimicking the function of GPCRs, its reliance on screw-sense responsive NMR probes has restricted further development into membrane environments. This thesis describes the successful development of a pyrene based screw-sense responsive fluorescence probe and its subsequent use in the development of a series of membrane-based GPCR mimics. This thesis has also details the preliminary steps towards the development of light-responsive controllers of screw-sense preference for nano-scale signal relay devices.
162

Exploring Process-Variation Tolerant Design of Nanoscale Sense Amplifier Circuits

Okobiah, Oghenekarho 12 1900 (has links)
Sense amplifiers are important circuit components of a dynamic random access memory (DRAM), which forms the main memory of digital computers. The ability of the sense amplifier to detect and amplify voltage signals to correctly interpret data in DRAM cells cannot be understated. The sense amplifier plays a significant role in the overall speed of the DRAM. Sense amplifiers require matched transistors for optimal performance. Hence, the effects of mismatch through process variations must be minimized. This thesis presents a research which leads to optimal nanoscale CMOS sense amplifiers by incorporating the effects of process variation early in the design process. The effects of process variation on the performance of a standard voltage sense amplifier, which is used in conventional DRAMs, is studied. Parametric analysis is performed through circuit simulations to investigate which parameters have the most impact on the performance of the sense amplifier. The figures-of-merit (FoMs) used to characterize the circuit are the precharge time, power dissipation, sense delay and sense margin. Statistical analysis is also performed to study the impact of process variations on each FoM. By analyzing the results from the statistical study, a method is presented to select parameter values that minimize the effects of process variation. A design flow algorithm incorporating dual oxide and dual threshold voltage based techniques is used to optimize the FoMs for the sense amplifier. Experimental results prove that the proposed approach improves precharge time by 83.9%, sense delay by 80.2% sense margin by 61.9%, and power dissipation by 13.1%.
163

Age differences in kinesthetic and static-position sense of the upper limb in unconstrained 3-D tasks

Coffman, Christopher Ross 01 August 2016 (has links)
We compared sense of movement and position in unconstrained 3-dimensional tasks in younger and older adults to investigate whether older adults have diminished kinesthetic sense. Active and passive kinesthesia were compared in a novel dynamic-position sense task and also in a static-position sense task. Older (65-85 years) and younger (18-22) adults performed tasks in which they moved the right arm to touch the right index tip to the moving and stationary left index (target) fingertip in different conditions. In the dynamic task the participant or experimenter moved the left upper limb and, after a variable delay, the subject moved the right arm to attempt to touch the right index-tip to the moving target index-tip. Participants performed the dynamic task with vision actively moving both limbs (VDA), without vision while actively moving both limbs (NVDA), and without vision with the experimenter moving the target limb (NVDP). In the static task the participant (NVSA) or experimenter (NVSP) moved the target limb to a position and held it stationary while the participant moved the right arm to attempt to touch the right index tip to the target fingertip. Both younger and older adults performed the dynamic task remarkably accurately with errors averaging less than 1.6 cm across the 3 conditions. Mean 3-dimensional distance errors averaged slightly (0.19 cm) larger in older adults in the dynamic task (F₁,₂₅=5.88, p=0.02). Variable distance errors did not differ between age groups in the dynamic task (F₁,₂₅=0.90, p=0.35). Small errors were observed in all conditions. NVDP had the largest mean distance errors (1.81 cm) of moving conditions, followed by NVDA (1.65 cm), and VDA had the smallest errors (1.27 cm) (F₂,₅₀=49.55, pcorr< .001, all post hoc tests less than p< 0.05). There was no evidence of errors depending on target index-tip peak speed or location. Interestingly, distance errors in the static tasks averaged 3.0 cm and were clearly larger than in the dynamic tasks (F₁,₂₅=57.78, p< 0.001). Within the two static conditions, average errors were 0.5 cm larger in the NVSP condition than in the NVSA condition (F₁,₂₅=7.56, p=0.01). Average distance errors trended to being larger in older adults in static conditions (F₁,₂₅=3.53, p=0.07). Variable distance errors were similar for the two age groups in the static conditions (F₁,₂₅=.25, p=0.35), averaging 1.77 cm in NVSP and 1.38 cm in NVSA (F₁,₂₅=.7.98, p< 0.01). These results suggest that regardless of age, availability of visual information, active/passive target limb movement, or reaching to static versus moving targets that adults are generally quite accurate at localizing fingertip position. The finding that accuracy in the static and dynamic tasks when vision was not allowed was only slightly better when the subjects actively moved the target arm (i.e., NVDA, NVSA) than when the target arm was moved by the experimenter (NVDP, NVSP) indicates that internal models may contribute only very slightly to proprioceptive localization of the upper limb. However, it is clear that kinesthetic sensory information from the periphery is sufficient to allow the central nervous system to accurately calculate position of the endpoint of the limb (tip of the index) while unconstrained in 3-dimensional space.
164

Den viktiga taluppfattningen - En studie om lärares undervisning för att stärka elevers taluppfattning

Grönlund, Elin, Nordström, Hanna January 2020 (has links)
Studiens syfte är att öka kunskapen om hur ett antal lärare i årskurs 1 planerar, undervisar och reflekterar över sin undervisning i matematik för att stärka elevers taluppfattning. Taluppfattningen är grundläggande för förståelsen för tals sammanhang och strukturer och är således avgörande för elevernas fortsatta utveckling inom matematik. Studien presenterar fem kategorier av undervisningsprinciper som enligt forskningen är viktiga gällande hur lärare kan bedriva sin undervisning för att stärka elevernas taluppfattning. Studien undersöker de deltagande lärarnas undervisning i relation till dessa principer genom klassrumsobservationer och intervjuer. På så sätt studeras både hur lärarnas verksamhet i klassrummen kan se ut samt hur lärarna uppger att de undervisar i syfte att stärka elevers taluppfattning. Resultatet pekar mot att lärarna har kunskap om samt bedriver en undervisning som verkar stärkande för taluppfattningen men i varierande omfattning. Detta leder även till att eleverna får varierande möjligheter till att utveckla sin taluppfattning.
165

Using Appreciative Inquiry to Improve RN Retention in a Clinical Float Pool

Buck, Janet 01 January 2015 (has links)
In an Idaho-based hospital, the registered nurse (RN) turnover rate in the float pool was excessively high. The purpose of this project was to examine the effect of Appreciative Inquiry (AI) on a RN's sense of community (SOC) in a float pool and an RN's intent to stay employed after attending an AI event. Although much had been written about nursing retention, AI, and SOC separately, there was nothing on how AI could be used to increase a RN's SOC or intent to stay employed. AI is a change management framework that has been used to engage employees in a meaningful way. The goal of this project was to engage RN float staff in a 6-hour AI workshop to generate ideas on improving the work environment. The SOC theory by McMillan and Chavis provided the context for measuring RN perception. It was anticipated that participation would lead to an increased SOC and an increased likelihood of staying employed in the float pool. The Sense of Community Index 2 survey was administered pre and postworkshop to a convenience sample of RNs (n = 22) recruited from the float pool. Additionally, RNs were asked before and after the workshop how likely they were to leave their current position in the next 12 months. Data analysis was a paired t test based on a 1-group pretest and posttest design. Demographic data were collected to describe the sample population. The results, although not statistically significant, showed both an increased SOC and an increased intent to leave following the AI workshop. The findings show that AI may be useful for increasing SOC. However, as a tool for nursing retention, both AI and SOC require better understanding. It is hoped this study will provide leaders with a starting point for further investigation into how AI and SOC can be used to improve the nursing work experience.
166

Kinesthetic perception and schizophrenia

Cherry, Charles Robert 01 January 1964 (has links)
It was the purpose of this study to compare normals with schizophrenic psychiatric patients as to their ability to reproduce movements perceived by kinesthetic stimulation. Kinesthetic perception, for the purpose of this study, was restricted to the reproduction of single arm-hand movements in a horizontal plane, away from the body. The magnitude of errors as a function of distance moved was defined as an indicator of kinesthetic perception.
167

Koncepty "Sense of coherence" a "Sense of national coherence" jako prediktivní faktory duševního zdraví v období pandemie COVID-19 / The concepts of sense of coherence and sense of national coherence as predictive resources of mental health during the COVID-19 pandemic

Miková, Barbora January 2021 (has links)
Given the negative consequences the COVID-19 pandemic has brought to both the physical and mental health, there is a growing need to find the ways how to support and strengthen psychological resilience and mental health of the individuals in such an unprecedent situation. Consequently, this thesis explores the A. Antonovsky's salutogenetic model of health with a focus on the concepts of sense of coherence (SOC) and sense of national coherence (SONC) as potential predictors of mental health during COVID-19 pandemic. In the theoretical part, the topic of mental health, it's coneptualisation and predictors are presented, with an emphasis on the concepts of SOC and SONC. Additionally, the review of present research on mental health during COVID-19 pandemic is included. The research project analyses the data obtained through an online survey as a part of an international research study investigating the predictive factors of mental health during COVID-19 pandemic. Data collection in Czech sample was conducted in December 2020 and January 2021, using the Mental Health Continuum, SOC-13 and SONC scales. The sample included 476 participants. Multiple regression analysis confirmed the SOC as a significant predictor of mental health during COVID-19 pandemic among Czech sample. However, the predictive value...
168

Investigation of Sense of Place Effects in an Online Learning Environment

Sumrall, Jeanne Lambert 09 May 2015 (has links)
In relation to the constructivist learning theory, understanding what a student may already know in order to use this knowledge as a scaffold for further education is imperative. The online classroom offers a unique and challenging environment for the evaluation of a student’s previous knowledge, especially in the field of geosciences where knowledge may be associated with geographic affiliation. An individual’s geological and meteorological sense of place may play an important role in evaluating a student’s previous knowledge in this field of study. To test this hypothesis, students in an online master’s program were given pre-knowledge surveys to evaluate their previous knowledge in Meteorology and Geology, as well as Geological and Meteorological sense of place surveys (Clary, R.M., and Wandersee, J.H., 2006; Clary, R.M., Wandersee, J.H., and Sumrall, J.L., 2013). Students were then categorized by geographic regions within the United States. Students were also given interest surveys at the end of their first year in the Masters program, and selected students were interviewed during their capstone field experience at the end of the second year of the program. Results suggest that there were subtle differences between regional groups of students throughout the study. More pronounced differences were noticed in the Meteorological pre-surveys than the Geological pre-surveys. Both sense of place surveys also indicated differences across regions, but the Meteorological sense of place survey showed greater regional differences when individual questions were analyzed. Interestingly, the participants who were interviewed at the end of the Masters program showed more geologically specific attachments as opposed to meteorologically specific attachments to areas that they considered to be “home.” The importance of moving and traveling throughout one’s life also became evident during the analysis of the interviews. Overall, this study of an online Master’s program concludes that geographic differences and moving/travel experiences among students matters to education in an online setting. The study emphasizes the importance for online instructors to evaluate teaching techniques based on geological and meteorological sense of place. By taking this into account in an online classroom, geographic disparities could be minimized and content interest levels could be increased.
169

The Effect of Trust and Sense of belonging on Civic participation: a Comparative study between Korea and Canada / Comparing Civic participation Between Korea and Canada

Kim, Jieun January 2021 (has links)
This research examines the difference in civic participation between Korean and Canadian citizens in two categories – social engagement (participation in general social groups) and political activity by using the Korea Social Integration Survey (SIS) and the Canadian General Social Survey (GSS). According to the results of this study, Canadians show higher social engagement than Koreans, while Koreans exhibit higher political activity, showing higher combined civic participation between individual citizens. This heightened civic participation by Koreans also reflects a stronger sense of collectivism. The results of the analysis on the effect of civic participation for each country show that, in Korea, both trust and sense of belonging were positively associated while in Canada, trust was negatively associated, and sense of belonging more positively associated than in Korea. The difference between the two countries can be attributed to the negative association found in institutional confidence as well. In Canada, active participation in politics implies that civic participation is part of more forward-looking action that shows greater individual preference and intention in comparison to civic participation of Korean citizens influenced more by collectivism. As such, this research implies that Korea needs to enhance individual civic identity in order to overcome collectivism. / Thesis / Master of Arts (MA)
170

Sense of Agency and Automation : A Systematic Review

Albutihe, Ismael January 2023 (has links)
Technological advancements have resulted in highly automated systems that are featured in many kinds of tools and devices, such as self-driving cars, autopilot in airplanes, and much more. Such systems have enabled tools to plan, decide, and act autonomously. This breakthrough resulted in a new manner of interacting with tools, known as "Human-Robot Joint Action" or "human-AI interaction," in which people and automated tools share control over the tasks that must be performed. However, little is known about the impact of such interactions on people and their sense of agency (SoA) as well as how much autonomy to grant to tools. As a result, the objective of this systematic review is to investigate and understand how automated tools affect human SoA, and if tools with different levels of automation affect our SoA differently. A search in two databases, Scopus, and MEDLINE EBSCO was conducted, and 8 articles were included. The findings suggest that the more automated the tool is, the less SoA participants experience, and that varied levels of automation may impact human SoA depending on the nature of the task. However, this topic is still in its infancy and more research is needed.

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