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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.
691

Normativa värden för läppkraft hos barn mellan fem och tio år : Relaterat till bilabial stavelseproduktion / Normative Values for Lip Force in Children between Five and Ten Years : Related to Bilabial Syllable Production

Pettersson, Mariana, Thorén, Cecilia January 2009 (has links)
Lip force has been found to affect the ability to achieve satisfying speech production and swallowing. A normative value for lip force in adults has been measured to 15 Newton (N). Corresponding value for children measured with Lip Force Meter 100 (LF100) does not exist. In the current study lip force was measured in children between the ages of five and ten years. The aim of the study was to obtain normative values for children with typical development in separate age groups. Production of syllable with initial bilabial plosive was further calculated to see if any correlation between lip force and syllable production existed. An examination of learning effect in repeated measures was also executed. The age group 5:0-5:11 only included four participants. This age group was therefore not included in the statistical measurements. The common mean for lip force in all children was 14.98 N. The mean for each age group was 12.75 N for 5:0-5:11 year olds, 14.69 N for 6:0-6:11, 16.93 N for 7:0-7:11, 14.97 N for 8:0-8:11 and 14.14 N for the age group 9:0-9:11 years. In the current study no significant differences in lip force was found between age groups. The common mean for syllable production in all children was 5.50 syllables/second. A significant difference between the ages six and seven year olds as well as six and nine year olds was found, where the older age groups showed higher values. No significant correlation was found between lip force and syllable production. Analysis of the learning effect over three lip force measurements showed tendencies for increased lip force at the last measure. The difference was not significant. In the present study no statistical measurements for gender differences were executed for each separate age group due to small numbers. Measurements in age group 6:0-9:11 showed tendencies for higher values of both lip force and syllable production for girls. These differences were not significant.
692

Biophysical and structural characterization of proteins implicated in glaucoma and Gaucher disease

Orwig, Susan D. 24 August 2011 (has links)
The inherited form of primary open angle glaucoma, a disorder characterized by increased intraocular pressure and retina degeneration, is linked to mutations in the olfactomedin (OLF) domain of the myocilin gene. Disease-causing myocilin variants accumulate within trabecular meshwork cells instead of being secreted to the trabecular extracellular matrix thought to regulate aqueous humor flow and control intraocular pressure. Like other diseases of protein misfolding, we hypothesize myocilin toxicity originates from defects in protein biophysical properties. In this thesis, the first preparative recombinant high-yield expression and purification system for the C-terminal OLF domain of myocilin (myoc-OLF) is described. To determine the relative stability of wild-type (WT) and mutant OLF domains, a fluorescence thermal stability assay was adapted to provide the first direct evidence that mutated OLF is folded but less thermally stable than WT. In addition, mutant myocilin can be stabilized by chemical chaperones. Together, this work provides the first quantitative demonstration of compromised stability among identified OLF variants and placing myocilin glaucoma in the context of other complex diseases of protein misfolding. Subsequent investigations into the biophysical properties of WT myoc-OLF provide insight into its structure and function. In particular, myoc-OLF is stable in the presence of glycosaminoglycans (GAGs), as well as over a wide pH range in buffers with functional groups reminiscent of such GAGs. Myoc-OLF contains significant â-sheet and â-turn secondary structure as revealed by circular dichroism analysis. At neutral pH, thermal melts indicate a highly cooperative transition with a melting temperature of ~55°C. A compact core structural domain of OLF was identified by limited proteolysis and consists of approximately residues 238-461, which retains the single disulfide bond and is as stable as the full myoc-OLF construct. This construct also is capable of generating 3D crystals for structure determination. This data, presented in Chapter 3, inform new testable hypotheses for interactions with specific trabecular extracellular matrix components. To gain further insight into the biological function of myoc-OLF, a facile fluorescence chemical stability assay was designed to identify possible ligands and drug candidates. In the assay described in Chapter 4, the target protein is initially destabilized with a chemical denaturant and is tested for re-stabilization upon the addition of small molecules. The assay requires no prior knowledge of the structure and/or function of the target protein, and it is amendable to high-throughput screening. Application of the assay using a library of 1,280 compounds revealed 14 possible ligands and drug candidates for myoc-OLF that may also generate insights into myoc-OLF function. Due to the high â-sheet content of monomeric myoc-OLF and presence of an aggregated species upon myoc-OLF purification, the ability of myoc-OLF to form amyloid fibrils was suspected and verified. The fibril forming region was confirmed to reside in the OLF domain of myocilin. Kinetic analyses of fibril formation reveal a self-propagating process common to amyloid. The presence of an aggregated species was confirmed in cells transfected with WT myocilin, but to a greater extent in cells transfected with P370L mutant myocilin. Both cell lines stained positive for amyloid. Taken together, these results provide further insights into the structure of myocilin and suggest a new hypothesis for glaucoma pathogenesis. Finally, in a related study, small molecule drug candidates were investigated to treat acid â-glucosidase (GCase), the deficient lysosomal enzyme in Gaucher disease, another protein conformational disorder. Three new GCase active-site directed 3,4,5,6-tetrahydroxylazepane inhibitors were synthesized that exhibit half inhibitory concentrations (IC50) in the low millimolar to low micromolar range. Although the compounds thermally stabilize GCase at pH 7.4, only one of the synthesized analogs exhibits chaperoning activity under typical assay conditions. This successful pharmacological chaperone is also one in which GCase is in its proposed active conformation as revealed by X-ray crystallography. Probing the plasticity of the active-site of GCase offers additional insight into possible molecular determinants for an effective small molecule therapy for GD.
693

Evaluation of approaches for the derivation of defensible sediment quality guidelines for application at Saskatchewan uranium operations

Burnett-Seidel, Charlene Carol 30 August 2011
Sediment quality guidelines (SQGs) or values (SQVs) are used to assess the potential risk of contaminants in sediment to aquatic organisms, specifically benthic invertebrates. The objectives of this research were to evaluate SQGs derived specifically for use by the uranium industry in Canada, propose alternative SQVs for use at uranium operations in northern Saskatchewan using a novel approach, and investigate the potentially bioavailable fractions of metals in sediment which could become an alternative measurement to the typically used total metal concentrations. The screening-level concentration (SLC) approach has been used in Ontario, Canada, to derive lowest effect levels (LELs) and severe effect levels for use as SQGs. This approach was adopted by the Canadian Nuclear Safety Commission (CNSC) to set guidelines for metals (As, Cr, Cu, Pb, Mo, Ni, Se, U, and V) and radionuclides (Ra-226, Pb-210, and Po-210) in sediment at northern Saskatchewan uranium mining and milling operations. The SLC approach is based on total metal and radionuclide concentrations in sediment, and corresponding benthic invertebrate community composition data for a specific sampling site. In this study, sediment chemistry (total metals and radionuclides) and benthic community data from northern Saskatchewan uranium operations were compiled and examined. Results indicated that the CNSC-derived SQGs had limited relationships to observed effects, or lack thereof, on benthic invertebrate communities near uranium operations in Saskatchewan. On a general basis, the correct alignment of at least one LEL exceedence at an effect site was observed 95% of the time, but on an element-specific basis many of the elements had concentrations at effect sites below their LELs. Furthermore, concentrations of the evaluated elements exceeded at least one LEL at 60% of the no-effect sites. The high number of exceedences of LELs at reference and no-effect sites (false-positives) calls to question the appropriateness of the CNSC-derived SQGs. To address the deficiencies of the SLC approach, a new approach was developed to derive alternative metal SQVs for the uranium industry in northern Saskatchewan that was based on the use of reference and no-effect site field data. Three different sets of NE values were derived using combinations of benthic invertebrate community effect criteria (abundance, richness, evenness, Bray-Curtis index). Additionally, reference (REF) values were derived based solely on sediment metal concentrations from reference sites. In general, NE values derived using abundance, richness, and evenness (NE1 and NE2 values) were found to be higher than the NE values derived using all four metrics (NE3 values). Derived NE values for Cr, Cu, Pb, and V did not change with the incorporation of additional effects criteria due to a lack of influence from the uranium operations on these metal concentrations (i.e., they were generally present at or near background levels). However, a gradient of exposure concentrations was apparent for As, Mo, Ni, Se, and U in sediment which allowed for acceptable exposure levels of these metals in sediment to be defined. The findings from this assessment proposed a set of new, alternate SQVs for use at the uranium industry in northern Saskatchewan. Often, only total metals concentrations are measured in the evaluation of contaminated sediment. However, this measure may over-estimate metal exposure to benthic invertebrates. Using sediment cores collected from near the Rabbit Lake and Key Lake uranium operations, along with a series of mixed-sediments (contaminated and reference sediment), metal bioaccumulation experiments using Chironomus dilutus were conducted in the laboratory. Metal concentrations in extracts from single extractions with either potassium phosphate or hydrochloric acid on wet and dried sediment, pore-water, and whole-sediment were used to evaluate metal bioaccumulation in test organisms. Depending on the metal, pore-water isolated using peepers generally exhibited the best relationship with tissue metal concentrations. Based on this finding, it is suggested that pore-water sampling using peepers (an in-situ dialysis device) be added to environmental sampling programs at Saskatchewan uranium operations so that sediment metal availability to benthic invertebrates can be better assessed. With the eventual development of a larger pore-water metals dataset, SQGs based on pore-water metals concentrations could likely be derived as an alternative to existing SQGs based on total metal concentrations in sediment.
694

Evaluation of approaches for the derivation of defensible sediment quality guidelines for application at Saskatchewan uranium operations

Burnett-Seidel, Charlene Carol 30 August 2011 (has links)
Sediment quality guidelines (SQGs) or values (SQVs) are used to assess the potential risk of contaminants in sediment to aquatic organisms, specifically benthic invertebrates. The objectives of this research were to evaluate SQGs derived specifically for use by the uranium industry in Canada, propose alternative SQVs for use at uranium operations in northern Saskatchewan using a novel approach, and investigate the potentially bioavailable fractions of metals in sediment which could become an alternative measurement to the typically used total metal concentrations. The screening-level concentration (SLC) approach has been used in Ontario, Canada, to derive lowest effect levels (LELs) and severe effect levels for use as SQGs. This approach was adopted by the Canadian Nuclear Safety Commission (CNSC) to set guidelines for metals (As, Cr, Cu, Pb, Mo, Ni, Se, U, and V) and radionuclides (Ra-226, Pb-210, and Po-210) in sediment at northern Saskatchewan uranium mining and milling operations. The SLC approach is based on total metal and radionuclide concentrations in sediment, and corresponding benthic invertebrate community composition data for a specific sampling site. In this study, sediment chemistry (total metals and radionuclides) and benthic community data from northern Saskatchewan uranium operations were compiled and examined. Results indicated that the CNSC-derived SQGs had limited relationships to observed effects, or lack thereof, on benthic invertebrate communities near uranium operations in Saskatchewan. On a general basis, the correct alignment of at least one LEL exceedence at an effect site was observed 95% of the time, but on an element-specific basis many of the elements had concentrations at effect sites below their LELs. Furthermore, concentrations of the evaluated elements exceeded at least one LEL at 60% of the no-effect sites. The high number of exceedences of LELs at reference and no-effect sites (false-positives) calls to question the appropriateness of the CNSC-derived SQGs. To address the deficiencies of the SLC approach, a new approach was developed to derive alternative metal SQVs for the uranium industry in northern Saskatchewan that was based on the use of reference and no-effect site field data. Three different sets of NE values were derived using combinations of benthic invertebrate community effect criteria (abundance, richness, evenness, Bray-Curtis index). Additionally, reference (REF) values were derived based solely on sediment metal concentrations from reference sites. In general, NE values derived using abundance, richness, and evenness (NE1 and NE2 values) were found to be higher than the NE values derived using all four metrics (NE3 values). Derived NE values for Cr, Cu, Pb, and V did not change with the incorporation of additional effects criteria due to a lack of influence from the uranium operations on these metal concentrations (i.e., they were generally present at or near background levels). However, a gradient of exposure concentrations was apparent for As, Mo, Ni, Se, and U in sediment which allowed for acceptable exposure levels of these metals in sediment to be defined. The findings from this assessment proposed a set of new, alternate SQVs for use at the uranium industry in northern Saskatchewan. Often, only total metals concentrations are measured in the evaluation of contaminated sediment. However, this measure may over-estimate metal exposure to benthic invertebrates. Using sediment cores collected from near the Rabbit Lake and Key Lake uranium operations, along with a series of mixed-sediments (contaminated and reference sediment), metal bioaccumulation experiments using Chironomus dilutus were conducted in the laboratory. Metal concentrations in extracts from single extractions with either potassium phosphate or hydrochloric acid on wet and dried sediment, pore-water, and whole-sediment were used to evaluate metal bioaccumulation in test organisms. Depending on the metal, pore-water isolated using peepers generally exhibited the best relationship with tissue metal concentrations. Based on this finding, it is suggested that pore-water sampling using peepers (an in-situ dialysis device) be added to environmental sampling programs at Saskatchewan uranium operations so that sediment metal availability to benthic invertebrates can be better assessed. With the eventual development of a larger pore-water metals dataset, SQGs based on pore-water metals concentrations could likely be derived as an alternative to existing SQGs based on total metal concentrations in sediment.
695

Further development of shaders for realistic materials and global illumination effects

Guo, Jun January 2012 (has links)
Shader programming is important for realistic material and global illumination real-time rendering, especially in 3D industrial fields nowadays, more and more customers of Visual Components Oy, a Finnish 3D software company have been found to be no longer only content with the correct simulation result, but also the result of realistic real-time rendering. This thesis project will provide a deep research on real world material classification, property definition and global illumination techniques in industrial fields. On the other hand, the Shader program for different materials and global illumination techniques are also created according to the classification and definition in this thesis work. Moreover, an external rendering tool Redway3D is evaluated as the reference and regarded as the considerable solution in the future development work.
696

Problems and Solutions for Conducting Online Live Instruction

Wang, Cheng-Jung 16 August 2004 (has links)
According to the literature there are still very few researches focusing on the Online Live Instruction in e-Learning. By Integrating IP-Based Video Conferencing System and Full Screen Capture with Live Streaming Broadcast System into an LMS, instructors can provide Online Live Instruction. In this kind of environment, teachers and students can interact together like in conventional classroom. This study explored the process of Online Live Instruction, solutions for the encountered problems are also provided. SOP (Standardized Operation Procedures) are developed on how to conduct Course Material Lecturing and Group Discussion & Summary Report activities. Suggestions about Online Live Instruction for teachers, teaching assistants and students are also included.
697

A Virtual Chinatown: the diasporic mediasphere of Chinese migrants in New Zealand

Li, Phoebe Hairong January 2009 (has links)
This is a study of the social dynamics of the current Chinese migrant community in New Zealand through a critical analysis of the Auckland-based Chinese-language media. It combines two research fields, international migration studies and media studies, to conceptualise Chinese-language media as a specific type of alternative media in contemporary New Zealand. The Chinese population in New Zealand has rapidly increased through immigration since the passage of the 1987 Immigration Act; Chinese now comprise 3.4% of the New Zealand population, and a wide variety of Chinese-language media have accordingly thrived in New Zealand. In contrast to New Zealand mainstream media, these Chinese media serve the specific needs and interests of newly arrived and only minimally acculturated Chinese migrants. The research was conducted in three phases: quantitative and qualitative data were acquired from the content of Chinese-language media during the period of the 2005 New Zealand general election; qualitative data were obtained from focus groups and interviews with members of the Chinese audience subsequent to the election; qualitative data were generated from Chinese media personnel. The findings suggest that these Chinese-language media closely reflect and depict recent PRC Chinese migrants’ perceptions of New Zealand and aspirations towards their new life in the host country. Within the global context of the Chinese diaspora in historical and contemporary times, this research also introduces a new angle for exploring the socio-economic impacts of China as a rising superpower on New Zealand and the Pacific Rim.
698

Full-page versus partial-page screen designs in web-based training: Their effects on learner satisfaction and performance

Grace, Phillip Eulon 01 June 2005 (has links)
This is a report on research regarding the screen layout of Web-based training (WBT) programs, conducted with an eye toward providing evidence-based guidance for the design and development of WBT interfaces. Specifically, the study investigated the relative instructional benefits of two general types of WBT screen design, full-page and partial-page, in terms of both learner performance and learner satisfaction. The main hypotheses of the study were that the full-page design option would yield significantly better outcomes in both categories of interest.The study employed a mixed-method design, generating both quantitative and qualitative data. The main phase of the study was experimental, following a factorial design to explore the relationships between a single treatment variable (WBT screen design) in two treatment conditions (partial-page WBT design and full-page WBT design) and two dependent variables (learner performance and learner satisfaction). Both a full-page and a partial-page version of the same Web-based tutorial were created, and 129 self-selected undergraduate students who reported having little or no experience with the tutorial subject matter were randomly assigned into the two treatment groups. Performance data were collected as scores on the tutorial's 18-item, multiple choice final exam, and satisfaction data were collected via a 10-item satisfaction survey. In addition, 59 of the study participants were randomly selected to participate in post-study session interviews.The results of the study yielded no significant difference between the two treatment groups for either learner performance or learner satisfaction; thus, making it impossible to reject the null hypothesis for either of the two primary research questions. The conclusion of this study was that the presence or absence of scrolling alone is not a significant factor either in how well a person performs in a WBT program or how satisfied they are with the learning experience . However, while analysis of the post-study session interview data supported this conclusion, the fact that a large majority of the interviewees stated a preference for the full-page, non-scrolling WBT interface design suggests that some elements inherent in the full-page design might warrant further consideration and/or study.
699

Biology of odoriferous defensive stink glands of the red flour beetle Tribolium castaneum

Lehmann, Sabrina 21 August 2015 (has links)
No description available.
700

Genetics of Drosophila hearing

Piepenbrock, David 27 September 2013 (has links)
No description available.

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