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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.
31

Neural Mechanisms of Motor Cortical Representation Modulation

Savoie, Mitchell January 2018 (has links)
TMS can be used to generate representational maps by delivering pulses at throughout a grid, centered over the most sensitive spot to elicit a resulting MEP called the motor hotspot. The areas of these maps are modulated by muscle contraction and have been shown to increase in area with increasing contraction intensity. Both intracortical inhibition (SICI), and intracortical facilitation (ICF) are paired pulse paradigms in which contraction causes a reduction in magnitude. The present study aimed to categorize changes in the above circuits and representational maps as well as expose a possible relationship between both metrics in the context of graded contraction. To study these questions 15 healthy, right-handed volunteers participated in a study measuring SICI, ICF and cortical maps under conditions of REST, 10, 20 and 30% of MVC of the right FDI muscle. SICI and ICF showed significant reduction between REST and no differences amongst contraction levels. However, SICI displayed a graded reduction through contraction levels when analyzed on a trial-by-trial basis sorted by actual contraction level. Cortical representational area increased from REST to all contraction states and between 10 and 30% MVC confirming the graded growth observed in previous studies. Further, analysis shows that SICI, ICF and area all exhibited the majority of their modulation within the first 10% of contraction. Both SICI and ICF were not significantly correlated to the growth in representational area. This may be in part due to participants’ variability in the level of contraction sustained during measures, which also made it unfeasible to conduct a correlation of trial-by-trial data between map area and circuit magnitudes. We present evidence to corroborate previous findings for the effects of contraction on intracortical circuits and representational area during graded contraction as well as contribute to the methodology of such investigations concerning the control of varied contraction. / Thesis / Master of Science (MSc)
32

An Efficient, Practical, Portable Mapping Technique on Computational Grids

Phinjaroenphan, Panu, s2118294@student.rmit.edu.au January 2007 (has links)
Grid computing provides a powerful, virtual parallel system known as a computational Grid on which users can run parallel applications to solve problems quickly. However, users must be careful to allocate tasks to nodes properly because improper allocation of only one task could result in lengthy executions of applications, or even worse, applications could crash. This allocation problem is called the mapping problem, and an entity that tackles this problem is called a mapper. In this thesis, we aim to develop an efficient, practical, portable mapper. To study the mapping problem, researchers often make unrealistic assumptions such as that nodes of Grids are always reliable, that execution times of tasks assigned to nodes are known a priori, or that detailed information of parallel applications is always known. As a result, the practicality and portability of mappers developed in such conditions are uncertain. Our review of related work suggested that a more efficient tool is required to study this problem; therefore, we developed GMap, a simulator researchers/developers can use to develop practical, portable mappers. The fact that nodes are not always reliable leads to the development of an algorithm for predicting the reliability of nodes and a predictor for identifying reliable nodes of Grids. Experimental results showed that the predictor reduced the chance of failures in executions of applications by half. The facts that execution times of tasks assigned to nodes are not known a priori and that detailed information of parallel applications is not alw ays known, lead to the evaluation of five nearest-neighbour (nn) execution time estimators: k-nn smoothing, k-nn, adaptive k-nn, one-nn, and adaptive one-nn. Experimental results showed that adaptive k-nn was the most efficient one. We also implemented the predictor and the estimator in GMap. Using GMap, we could reliably compare the efficiency of six mapping algorithms: Min-min, Max-min, Genetic Algorithms, Simulated Annealing, Tabu Search, and Quick-quality Map, with none of the preceding unrealistic assumptions. Experimental results showed that Quick-quality Map was the most efficient one. As a result of these findings, we achieved our goal in developing an efficient, practical, portable mapper.
33

An evaluation of digital elevation models and geotechnical properties of the glacial deposits in Franklin County, Ohio, using a geographic information system

Bates, Jeffrey Kenneth, January 2007 (has links)
Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 196-208).
34

Algorithms for DNA restriction mapping /

Fasulo, Daniel. January 2000 (has links)
Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 81-84).
35

Remote identification of wetlands in Mahoning and Trumbull County, Ohio

Krzys, Bethaney L. January 2008 (has links)
Thesis (M.A.)--Kent State University, 2008. / Title from PDF t.p. (viewed Dec. 22, 2009). Advisor: Mandy Munro-Stasiuk. Keywords: remote sensing, wetland, wetland identification, GIS. Includes bibliographical references (p. 158-161).
36

Mapping in the Maydeae : Tripsacum genes in Zea

Winata, T. Therry Indra January 2000 (has links)
Comparisons using cDNA (cloned DNA from expressed genes) from different species greatly increases our understanding and ability to identify the changes in the genetic content of related species through the process of evolution.This research utilized cDNA isolated from developmentally staged female flowers of Tripsacum, a relative of modem maize (corn) with differing modes of reproductive behaviors. The gene expression clone libraries potentially carry the gene(s) responsible for the regulation of fertility, both apomixis and sexual reproduction, in Tripsacum sp. A set of yeast genes with known functions in the reproductive cell division known as meiosis were also investigated, but failed to hybridized to DNA of the maize mapping population.The Tripsacum cDNAs, E2-42 and M2-62, showed monomorphic band patterns, i.e., no differences between individuals. Possibility the quantity of E242 and M2-62 Tripsacum cDNAs for these locus were highly conserved with respect to the fragment lengths generated by restriction digestion of the test individuals. The Tripsacum cDNA sequence L4-14 revealed polymorphic bands patterns when used as a probe for mapping. The L4-14 polymorphisms were scored as both 1:2:1 and 3:1 segregation ratios and mapped to a subset of ordered loci from the Maize Database genome bank, University of Missouri. Two genetic map regions were identified as linked to the L4-14 locus. These regions included bin 6.05-6.08 of chromosome 6 and bin 8.00-.05 of chromosome 8. Linkage to two different chromosomal regions indicated that the L4-14 sequence may be duplicated within the maize genome. Results and discussion of this investigation and analyses are presented. / Department of Biology
37

A satellite derived map of ecological systems in the East Gulf Coast plain, USA

Kleiner, Kevin James, January 2007 (has links) (PDF)
Thesis (M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (ℓ. 76-90)
38

Issues affecting the utility of computer-based mapping applications

Smee, Peter E. H. January 1995 (has links)
This thesis records an investigation of the issues that affect the utility of computer-based mapping applications - where a computer-based mapping application provides a computer-generated environment to facilitate the construction of concept maps. 'Concept map' is a term used to describe a graphical representation, the purpose of which is to informally express ideas and the associations between ideas, whilst facilitating the generation and sorting of ideas. The work reported is the first of its kind to compare and contrast the strengths and weaknesses of the different media with which concept maps can be constructed. The work is exploratory, combining investigation with software development. A brief overview of the content of the work completed is as follows: • The literature relating to concept mapping was reviewed to identify the likely needs of those engaged in mapping activities. • A significant sample of people was surveyed in order to ascertain the perceived needs of those engaged in mapping. • The software currently available to draw maps was surveyed in order to assess the utility of computer-based mapping applications, with respect to the perceived needs of mappers. • A prototype computer-based mapping application was developed to act as a focus for mappers' comments. • As a result of feedback from users of the prototype computer-based mapping application, it was discovered that the main way in which people create maps is to generate and sort a few ideas at a time. • The prototype software was further developed, as a result of feedback from mappers, . and in its final form has been made available in the public domain. • A glossary of terms was developed, by which the designers and users of computer-based mapping applications can assess the utility of any given piece of software, in the light of the tasks mappers wish to achieve.
39

Explorations in City Image: An Investigation of Tools of Perception and Representation in Urban Design

Dawson, Thomas Edward 07 July 2004 (has links)
The map is vitally important for space design. Maps allow designers to record and filter impossibly complex information about an environment. Designers try to capture a variety of aspects of a site through the use of graphic tools like maps and drawings. While there is a long-established conventional graphic language for recording characteristics of a site, this language is often inadequate when one attempts to explore and capture subtler perceptual qualities of urban environments. Many of these perceptual qualities can greatly inform a design and some designers have invented creative mapping strategies to record and analyze difficult aspects of a site. This position paper follows the work of innovative designers who creatively map perceptual qualities of urban landscapes. The theories and practices of these designers have informed my development of new creative tools for mapping my perception of space. The design portion of this thesis takes place in the Mexican War Streets Neighborhood of Pittsburgh, Pennsylvania and results in a plaza for the local Mattress Factory Art Museum. The design phase uses and evaluates traditional perception and representational tools of urban design. New creative maps are used to express what the traditional tools cannot. These creative maps are used to derive the concept for the site design as well as the design of the major site elements and materials. / Master of Landscape Architecture
40

Comparing functional connectivity across the whole brain

Ing, Alex January 2014 (has links)
Functional connectivity MRI (fcMRI) based on the blood oxygen level dependent (BOLD) contrast has become a widely used modality for mapping the brain's functional architecture. In recent years, applications of fcMRI have led to numerous breakthroughs in both clinical research and basic sciences. However, there are a number of unresolved issues associated with fcMRI relating to both the modality itself, and to methods used to analyse fcMRI data. The aim of this thesis was twofold: to develop novel data analysis procedures, and to demonstrate their feasibility in dedicated neuroimaging studies. Subject head movement can act as a significant confound in fcMRI. Investigating this issue, it was found that subject motion can induce significant increases and decreases in functional connectivity across the brain. A novel motion correction method was developed, which proved more effective than standard procedures in the removal of motion induced connectivity changes. The BOLD contrast is not a direct measure of neural activity, it measures the hemodynamic response caused by changes in neural activity, which varies across the brain. The hypercapnic state is often used to calibrate the BOLD signal. This calibration crucially relies on the assumption that hypercapnia does not affect neuronal activity. An investigation into the hypercapnic state revealed that it is associated with both increases and decreases in functional connectivity. Whilst carrying out this investigation, a number of limitations, such as the need for a hypothesis and information loss, were identified in standard data analysis procedures. Three novel methods were developed to address these limitations. The efficacy of these methods was demonstrated in four different neuroimaging studies, which investigated functional connectivity changes induced by hypercapnia, aerobic exercise, hormonal changes across the menstrual cycle, and electroconvulsive therapy treatment in depression.

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