Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 112-115). Also available on the World Wide Web.

Thesis (Ph. D.)--University of Texas at Austin, 2005. / Vita. Includes bibliographical references.

79f. / Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2013-04-23T18:07:27Z No. of bitstreams: 1 Dissertacao - Joaquim Dultra.pdf: 1334173 bytes, checksum: 73853acd89ce2488b9579e8a8151fb44 (MD5) / Approved for entry into archive by Rodrigo Meirelles(rodrigomei@ufba.br) on 2013-05-08T11:51:15Z (GMT) No. of bitstreams: 1 Dissertacao - Joaquim Dultra.pdf: 1334173 bytes, checksum: 73853acd89ce2488b9579e8a8151fb44 (MD5) / Made available in DSpace on 2013-05-08T11:51:15Z (GMT). No. of bitstreams: 1 Dissertacao - Joaquim Dultra.pdf: 1334173 bytes, checksum: 73853acd89ce2488b9579e8a8151fb44 (MD5) Previous issue date: 2007 / Este estudo determinou sítios anatômicos inter-radiculares mais seguros para instalação de mini parafusos ortodônticos. Foram analisadas 20 hemi-arcadas da maxila e 20 hemi arcadas da mandíbula, nas regiões inter-radiculares entre canino e pré-molar (CP), primeiro e segundo pré-molares (PP), segundo pré-molares e primeiro molares (PM) e primeiro e segundo molares (MM), através de tomografia computadorizada. Essas regiões foram avaliadas em três níveis com intervalos de três milímetros, a partir da crista óssea alveolar (N1,N2,N3), sendo cada nível mensurado no sentido vestíbulo-lingual (VL) e mésio-distal (MD). Os resultados mostraram que na maxila o maior comprimento médio VL foi observado na região MM/N2 (11,69mm) e o menor comprimento médio VL foi observado na região MM/N3 (8,47mm). O maior comprimento médio maxilar no sentido MD foi observado na região PM/N3 (2,38mm) e o menor comprimento médio no sentido MD foi evidenciado na região MM/N3 (0,76mm). Na mandíbula, o maior comprimento médio VL foi observado na região MM/N3 (15,05mm) e o menor comprimento médio VL foi observado na região CP/N1 (7,98mm). O maior comprimento médio MD na mandíbula foi observado no PM/N3 (3,72mm) e o menor comprimento médio MD foi observado na região CP/N1 (1,51mm). Os resultados obtidos sugerem a escolha de sítios anatômicos, entretanto, as variações individuais devem ser consideradas e todos os pacientes devem receber avaliação individualizada. / Salvador

The thesis falls naturally into four parts. The first constitutes a world-wide survey of the methods used in practice to design prestressed, cement grouted rock anchors. The major topics of overall stability and system geometry, the rock-grout and grout-steel interfaces, and grout and tendon selection, are reviewed in turn. Comparisons between the standard methods of practice, and the findings from theoretical and field studies, reveal important areas of uncertainty and contradiction, particularly with regard to the mechanisms of load transfer from tendon to rock. Part 2 describes the author's full scale test anchor programme, conducted at Withnell, Lancashire, devised to investigate the major problems associated with load transfer which were highlighted in Part 1. Full details are provided of the site and its geology, and the methods of construction, testing, recording and analysis employed. Most emphasis placed on the results obtained from the fifty-seven anchors: these are fully discussed and wherever possible compared with data presented in the review. The third part deals with the long term performance of rock anchor systems. Analogous to Parts 1 and 2, one chapter is devoted to a review of relevant published information, whereas the other chapter details the author's case study of ten production anchors at H.M. Dockyard, Devonport. In Part 4, conclusions on the field test programmes are summarised and indications are given of topics meriting further research.

Current methods for assessing the integrity of ground anchorages during service are primarily restricted to monitoring by load cells or load lift-off testing. Both are expensive and lift-off testing is time consuming and can damage the anchorage construction below the anchor head. Hence, only typically 5-10% of anchorages are monitored in service. As a result, The Institution of Civil Engineers reported that non-destructive test methods for ground anchorages need to be developed as a high priority (ICE, 1992). The Universities o f Aberdeen and Bradford have been conducting research since 1986 to investigate the response o f rock anchorages to dynamic loading arising from blasting operations. Full scale field trials were conducted during the construction of two tunnels in North Wales. An important finding from the research revealed that certain characteristics of the dynamic response of a rock bolt resulting from blasting operations, were similar for different blast sequences. This indicates that the dynamic response o f an anchorage system is dependant on the construction of the anchorage and the characteristics of the co-vibrating rock mass. Consequently, the University of Aberdeen has developed a new non-destructive condition monitoring and integrity assessment system for ground anchorages (GRANIT ™). A range of patent applications have been successful world-wide and the system has been exclusively licensed to AMEC Civil Engineering Limited. The system operates by applying an axial tensile impact load to the free end of an intact anchorage immediately after installation. The resulting vibrational response is monitored by an accelerometer, located at the anchorage head, which produces a datum signature for that anchorage. The condition of the anchorage is then inferred by comparing subsequent response signatures with the datum. A change in the signature indicates that there may be a potential change in the integrity of the anchorage. Artificial Intelligence systems are employed to compare response signatures. As part of the research programme, the author conducted commissioning tests on small scale laboratory test rigs and was responsible for the development of a prototype non-destructive test system, which included a means of applying an impact load and recording the vibrational response. In addition, the author conducted full scale laboratory tests and field trials to investigate the effect of prestress on the dynamic response of ground anchorage systems. As a result, the prototype non-destructive test system has been employed to successfully predict the amount of load within an anchorage installation.

Abstract Laminins are basement membrane glycoproteins consisting of three polypeptide chains α, β and γ. Until now 12 members of the protein family have been characterized and all isoforms have an αβγ chain composition, but they assemble in varying combinations of chain variants. The functional properties of laminins include cell adhesion, proliferation, differentiation, growth and migration. Laminin-5 has a chain composition of α3β3γ2 with the distribution mainly restricted to epithelial basement membranes, where its biological functions involve anchorage and locomotion of cells. The importance of this protein for the attachment of basal keratinocytes is clearly demonstrated by the fact that all genes encoding its chains have been shown to be mutated in the severe skin blistering disease Epidermolysis bullosa junctionalis. The present study focused on investigations of the role of the laminin-5 isoform and particularly its γ2 chain in cell adhesion and migration. The role of the short arm of the laminin γ2 chain in the process of epithelial cell attachment is to serve as a kind of a bridging molecule to the extracellular environment, because it does not have any cell binding activity by itself. It was also shown that the newly synthesized γ2 chain participates in the complex process of cell migration, probably as one of the first attachment components for moving cells. Thus, as a migration and differentiation-associated molecule, laminin-5 was considered a potential marker for detection of malignant processes where cell movement plays a role. Subsequently it was shown that the γ2 chain is expressed not only in a restricted manner in human epithelial tissues, but also in a number of human epithelium-derived cancers. In some carcinomas, expression of the γ2 chain appeared to be a characteristic of cancer cells with invasive properties. Examination of over 50 dysplasias and cervical tumors revealed that γ2 chain antibodies were able to distinguish between lesions with or without invasive capacity. This is the first systematic study of epithelial cancers where γ2 chain antibodies have been shown to be a useful marker in the histopathological diagnostics. In addition, this study showed in a mouse tumor model that the γ2 chain of laminin-5 has a potential for being of use for in vivo tumor imaging.

M.Tech. (Civil Engineering) / Recoverable anchor screws are widely used in the construction of massive concrete structures such as dams, channels, tunnels and multi-story buildings to fix temporary cantilever forms. Attempts have been made before to quantify the failure capacities of recoverable anchor screws. However, such tests were conducted and reported on more than 25 years ago and were limited to a small number of tests on concrete strengths not exceeding 20 MPa, whereas most concrete constructions now exceed such strengths. The aim of this dissertation was to review the existing theories on the use of concrete anchors in practice and to apply the appropriate theories to recoverable anchor screws. In doing so, the overall shear strength of these screws was determined by considering existing theoretical standards and norms, and by testing the tensile capacity in the laboratory. The failure behaviour of recoverable anchor screws in various concrete strengths and construction applications is reviewed and is discussed based on both theory and the laboratory results obtained. The empirical formulas derived for the practical use of recoverable anchor screws are presented in standard form. These formulas provide an easy reference for engineering professionals in practice to determine the load capacity of recoverable anchor screws in various concrete strengths and construction applications. In conclusion, the required future research on recoverable anchor screws is presented.

<p>A unified and consistent design procedure is proposed for column base anchorages loaded in shear and tension. A literature review of previous work was done to identify discrepancies. A design procedure for anchorages loaded in shear, tension and combined shear and tension was developed which attempted to coordinate c;lnd resolve the discrepancies in previous work. A design methodology utilizing shear lugs was developed. The overall design procedure is for column bases loaded in shear and tension and uses two design methods:</p> <p>Method 1: Headed anchor bolts are used to resist both shear and tension loads.</p> <p> Method 2: A shear lug welded to the bottom of the base plate resists shear loads and the headed anchor bolts resist only tension loads.</p> <p>The proposed design method differs form the design method used by Shipp and Haninger (Reference 23) as follows:</p> <p> 1. The proposed procedure incorporates both shear and tension design stress based on the ultimate strength of the anchor bolts times a reduction factor.</p> <p> 2. Separate capacity reduction factors are introduced for shear and tension.</p> <p> 3. The use of shear lugs is incorporated in the proposed design.</p> <p> 4. The incorrect use of the "shear-friction" concept is noted and not used in the design.</p> <p> 5. The safety factor for the required embedment depth is applied to the projected area of the failure cone not the embedment depth of the bolt.</p> <p> Several design examples are presented using the two methods. A computer program (using Microsoft QuickBasic 4.0) has also been developed using the proposed design procedure.</p> / Master of Engineering

Indiana University-Purdue University Indianapolis (IUPUI) / The unfolded protein response (UPR) is important for cell adaptation to accumulation of unfolded proteins in the endoplasmic reticulum (ER). A central UPR sensor of ER stress is PKR- like ER Kinase (PERK), which phosphorylates eIF2 to reduce global translation and help mitigate ER stress. While this is a survival mechanism that serves to save the cell from catastrophic events during ER stress, PERK can also be activated in cancer cells due to genetic changes and exposure to stresses inherent in the tumor micro-environment. Published reports have indicated that PERK is activated in cancer cells in response to hypoxia, nutrient deprivation, matrix detachment, and increased protein load by oncogene activation to facilitate cell survival. The UPR features PERK and another ER stress sensory protein, IRE1α, which also regulates the dynamic assembly of the actin cytoskeleton; loss of either PERK or IRE1α functions decrease cell migration activity. We hypothesized that PERK is required for anchorage-independent survival of the cancer cell line HCT116 and that PERK is essential for cell migration. Consistent with these premises, inhibition of PERK using pharmacological inhibitors GSK2656157 and LY-4 in suspended cells showed reduced growth. Furthermore, PERK-deficient cells showed reduced migration in transwell migration assays as compared to their wild type counterpart. These results suggest that PERK facilitates anchorage-independent growth of cancer cells and cell migration.

Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 86-88). Also available on the World Wide Web.