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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.
181

Macular pigment optical density measurements by one-wavelength reflection photometry – Influence of cataract surgery on the measurement results

Komar, Bogdana 18 June 2015 (has links)
Purpose: The main objective of the present study was the investigation of possible influence of lens opacification on macular pigment optical density (MPOD) measurements. Methods: 86 eyes of 64 patients (mean age 73.4(±8.3)years) were included in the study. MPOD was prospectively measured using one-wavelength reflection method (Visucam500, Carl Zeiss Meditec AG) before and after cataract extraction with implantation of a blue-light filtering intraocular lens (AlconSN60WF). The median of the maximum optical density (MaxOD) and the median of the mean optical density (MeanOD) measurements of macular pigment across the subject group were evaluated. Results: Statistically significant differences were noticed between pre-operative and post-operative measurements, the absolute values were generally lower after cataract extraction. The following median(lower/upper quartile) differences across the group were determined: MaxOD -33.8%(-46.2%/-19.1%), MeanOD -44.0%(-54.6%/-26.6%). Larger changes were observed in elderly patients (<70years of age: (n=25eyes) MaxOD -13.4%(-20.5%/3.6%), MeanOD -23.6%(-30.5%/-15.3%) versus patients ≥70years: (n=61eyes) MaxOD -40.5%(-53.2%/-30.1%), MeanOD -47.2%(-57.8%/-40.1%)) and in patients with progressed stage of cataract. MaxOD for lens opacification grade 1:(n=9eyes) -27.4%(-42.1%/-19.6%), 2:(n=26eyes) -35.0%(-44.2%/-25.3%), 3:(n=21eyes) -34.4%(-45.4%/-11.4%), 4:(n=25eyes) -32.6%(-53.2%/-6.4%) and 5:(n=5eyes) -53.5%(-61.7%/-38.7%) and MeanOD for cataract stage 1:(n=9eyes) -42.6%(-46.0%/-26.0%), 2:(n=26eyes) -44.1%(-51.8%/26.2%), 3:(n=21eyes) -45.7%(-54.7%/-24.7%), 4:(n=25eyes) -39.5%(-59.4%/-26.1%), 5:(n=5eyes) -57.0%(-66.1%/-51.4%). Conclusions: As established by comparison of pre- to post-operative measurements, cataract presented a strong effect on MPOD measured by one-wavelength reflection method. Particular care should therefore be taken when evaluating MPOD using this method in elderly patients with progressed stage of cataract. Future optimization of correcting parameters of scattered light and consideration of cataract influence may allow more precise evaluation of MPOD.
182

Improvement of Conspicuity for Trailblazing Signs

Barker, Julie A. 28 April 1998 (has links)
This document represents efforts to design and evaluate a new sign design for emergency route trailblazing in a two-part series. Study 1 was an off-road field experiment conducted to determine the best color combination and letter design for the emergency sign. Based upon Study 1 results, black on coral, black on light blue, and yellow on purple signs were chosen for further testing against a baseline black on orange sign, all with 125-mm, D series letters. Study 2 was an on-road field study of conspicuity, conducted using an instrumented vehicle through a construction zone-related detour, and a survey questionnaire. The findings indicated that use of a color combination other than traditional black on orange will improve driver performance and safety when used for trailblazing during critical incidents. Based on the conclusions and other anecdotal evidence, the following recommendations were made: 1) Do not use black on orange signs for trailblazing around a critical incident if an existing detour/construction zone is in place; 2) Do not use a black on coral sign for trailblazing around a critical incident; 3) A light blue on black sign is recommended due to generally favorable subjective ratings and for minimization of turn errors in an overlapping detour; however, the black on light blue sign may resemble regulatory signs when headlights reflect onto it; and 4) If reject black on light blue signs based on (3), consider using yellow on purple signs, which resulted in fewer turn errors than black on orange and received generally favorable ratings. / Master of Science
183

Co-designing with Older Adults for Voice Assistive Technology

Wang, Yiting January 2020 (has links)
No description available.
184

Post-Translational Modification By Isolevuglandins: Retinal Detection, Effects, and Prevention

Charvet, Casey Douglas 16 August 2013 (has links)
No description available.
185

Computer-Based Cognitive Training for Age-Related Cognitive Decline and Mild Cognitive Impairment

Fortman, James Alexander 27 November 2012 (has links)
No description available.
186

Исследование жизнестойкости подростков с задержкой психического развития : магистерская диссертация / Adolescents with mental retardation hardiness research

Литвинова, Ю. С., Litvinova, Y. S. January 2018 (has links)
The object of the research was the hardiness of adolescents with mental retardation. The subject of the research was the personal characteristics, manifestations of hardiness, as well as features of the coping-strategies choice of adolescents with mental retardation. The master's thesis consists of an introduction, two chapters, conclusion, list of references (153 sources) and an Appendix, including the test results forms for the subjects, as well as the results of mathematical data processing performed in the SPSS Statistic program. The volume of the master's thesis is 158 pages, which contains 4figures and 32 tables. In conclusion, the results of the theoretical and empirical parts of the work, as well as conclusions on the hypotheses put forward, the practical significance of the study and the possible prospects for further development of this problem are described in a generalized form. / Объектом исследования явилась жизнестойкость подростков с задержкой психического развития. Предметом исследования стали личностные характеристики, проявления жизнестойкости, а также особенности выбора стратегий совладающего поведения подростков с задержкой психического развития. Магистерская диссертация состоит из введения, двух глав, заключения, списка литературы (153 источника) и двух приложений, включающих в себя бланки с результатами тестирования для испытуемых, а также результаты математической обработки данных, выполненные в программе SPSS Statistic. Объем магистерской диссертации 158 страниц, на которых размещены 4 рисунка и 32 таблица. В заключении в обобщенном виде изложены результаты теоретической и эмпирической частей работы, а также выводы по выдвинутым гипотезам, обоснована практическая значимость исследования и описаны возможные перспективы дальнейшей разработки данной проблематики.
187

Epigenetic Drifts during Long-Term Intestinal Organoid Culture

Thalheim, Torsten, Siebert, Susann, Quaas, Marianne, Herberg, Maria, Schweiger, Michal R., Aust, Gabriela, Galle, Joerg 03 May 2023 (has links)
Organoids retain the morphological and molecular patterns of their tissue of origin, are self-organizing, relatively simple to handle and accessible to genetic engineering. Thus, they represent an optimal tool for studying the mechanisms of tissue maintenance and aging. Long-term expansion under standard growth conditions, however, is accompanied by changes in the growth pattern and kinetics. As a potential explanation of these alterations, epigenetic drifts in organoid culture have been suggested. Here, we studied histone tri-methylation at lysine 4 (H3K4me3) and 27 (H3K27me3) and transcriptome profiles of intestinal organoids derived from mismatch repair (MMR)-deficient and control mice and cultured for 3 and 20 weeks and compared them with data on their tissue of origin. We found that, besides the expected changes in short-term culture, the organoids showed profound changes in their epigenomes also during the long-term culture. The most prominent were epigenetic gene activation by H3K4me3 recruitment to previously unmodified genes and by H3K27me3 loss from originally bivalent genes. We showed that a long-term culture is linked to broad transcriptional changes that indicate an ongoing maturation and metabolic adaptation process. This process was disturbed in MMR-deficient mice, resulting in endoplasmic reticulum (ER) stress and Wnt activation. Our results can be explained in terms of a mathematical model assuming that epigenetic changes during a long-term culture involve DNA demethylation that ceases if the metabolic adaptation is disturbed.
188

Immunosenescence in Choroidal Neovascularization (CNV): Transcriptional Profiling of Naïve and CNV-Associated Retinal Myeloid Cells during Aging

Schlecht, Anja, Thien, Adrian, Wolf, Julian, Prinz, Gabriele, Agostini, Hansjürgen, Schlunck, Günther, Wieghofer, Peter, Boneva, Stefaniya, Lange, Clemens 02 February 2024 (has links)
Immunosenescence is considered a possible factor in the development of age-related macular degeneration and choroidal neovascularization (CNV). However, age-related changes of myeloid cells (MCs), such as microglia and macrophages, in the healthy retina or during CNV formation are illdefined. In this study, Cx3cr1-positive MCs were isolated by fluorescence-activated cell sorting from six-week (young) and two-year-old (old) Cx3cr1GFP/+ mice, both during physiological aging and laser-induced CNV development. High-throughput RNA-sequencing was performed to define the age-dependent transcriptional differences in MCs during physiological aging and CNV development, complemented by immunohistochemical characterization and the quantification of MCs, as well as CNV size measurements. These analyses revealed that myeloid cells change their transcriptional profile during both aging and CNV development. In the steady state, senescent MCs demonstrated an upregulation of factors contributing to cell proliferation and chemotaxis, such as Cxcl13 and Cxcl14, as well as the downregulation of microglial signature genes. During CNV formation, aged myeloid cells revealed a significant upregulation of angiogenic factors such as Arg1 and Lrg1 concomitant with significantly enlarged CNV and an increased accumulation of MCs in aged mice in comparison to young mice. Future studies need to clarify whether this observation is an epiphenomenon or a causal relationship to determine the role of immunosenescence in CNV formation.
189

Plasma Biomarkers for Age-Related Macular Degeneration

NI, JIAQIAN 13 March 2009 (has links)
No description available.
190

Detecting Rare Haplotype-Environment Interaction and Dynamic Effects of Rare Haplotypes using Logistic Bayesian LASSO

Xia, Shuang 30 December 2014 (has links)
No description available.

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