Ovarian cancer is the 5th leading cause of cancer death in women in the United States and is the most fatal gynecological malignancy. High grade serous ovarian cancer (HGSC) is the most common and deadly type of ovarian cancer largely due to the rapid metastasis throughout the peritoneum (abdominal cavity wall and organ lining). Metastatic spread of ovarian cancer usually occurs before diagnosis and can lead to bowel obstruction, organ failure, ascites, cachexia, infection and sepsis, and pulmonary embolism all causing death. Current methods to detect early stage ovarian cancer do not increase overall survival. A better understanding of the metastatic ability of ovarian cancers and the mechanism of cancer cell dissemination are critical to the development of new treatments for this devastating disease. In particular, investigation of pathways that affect early metastasis may indicate treatments that will lower disease burden and may suggest biomarkers of recurrent and/or chemotherapy resistant disease. Notch3 expression correlates with worse prognosis, chemotherapy resistance, and increased tumorigenic cell behaviors in HGSC. Here, we demonstrate that Notch3 acts to promote early stages of metastasis in a model of HGSC using the murine ID8 IP2 ovarian surface epithelial cell line. ID8 IP2 cells have little to no endogenous Notch3 expression and model metastatic disease when introduced intraperitoneally. We investigated the role of Notch3 by ectopically expressing the intracellular domain of murine Notch3 to induce constitutive Notch3 signaling in ID8 IP2 cells and verified Notch signal activation by target gene assessment. Induction of Notch3 signaling in ID8 IP2 reduced survival and accelerated disease burden, as measured by ascites accumulation, after intraperitoneal introduction of cells into nude mice. We interrogated downstream targets in Notch3 activated cells by RNA-Seq and found that Notch3 induced a significant enrichment of adhesion and extracellular matrix pathways. Notch3 active cells showed increased ITGA1 expression and increased adhesion on collagens I and IV in vitro, suggesting that increased adhesion to collagen-rich peritoneal surfaces drives the observed increase in tumor burden. Notch3 active cells showed reduced migration on surfaces coated with multiple types of extracellular matrix and no detectable increase in invasion through extracellular matrix, indicating that Notch3 effects may be specific to the initial adhesion of tumor cells and not the later stages of metastasis. These results demonstrate that Notch3 upregulates the expression of specific adhesion genes in ovarian cancer cells and this promotes increased attachment to the collagen-rich extracellular matrix. The implications of this study are that oncogenic Notch signal activation, as documented in human disease, may promote dissemination and metastasis of primary and/or recurrent HGSC by increasing attachment to the peritoneal lining.

As the semiconductor technology moves further into scaled down device structures, modern day complexities in the fabrication processes become more prevalent. This thesis focuses on the issues associated with mechaincal and adhesion failure in low dielectric constant (low-k) thin films. In this thesis the four point bend test and nanoscratch test method was used for evaluating adhesion of boro-phosphate-silicate glass (BPSG) and tetraethylorthosilicate (TEOS) low-k thin films to silicon subtrates. Nanoindation tests were also performed on the low-k films to evaluate material properties such as hardness and elastic modulus. The sample preparation and testing set up for the four point bend test and nanoscratch test were observed to be greatly disparate. Nanoscratch and nanoindentation sample preparation and sample testing were able to be carried out much quicker than in four point bending. It was observed that nanoscratch testing holds an immense potential for reducing the time needed to evaluate thin film adhesion then in FPB testing. Nanoindentation performed on the BPSG and TEOS dielectric thin films showed uniform mechinacal properties throughout the surface of the films. The adhesion energy for BPSG and TEOS using FPB testing ranged from 29.5390 J/m² - 3.0379 J/m². While the adhesion energy for BPSG and TEOS using nanoscratch testing ranged from 0.0012 J/m² - 0.0028 J/m². It was observed that the difference in adhesion energy for FPB and nanoscratch testing was due to differing failures modes.

Cell signaling pathways are frequently used in multiple tissue and stage-specific contexts during multicellular development. The integration of these signaling pathways by transcriptional enhancers controls the tissue specific gene expression necessary for proper development. Enhancers are segments of DNA that interpret developmental signals to produce patterns of gene expression. A set of operational rules defines how different enhancers targeted by the same signals interpret and act on these signals. Using the Drosophila model system, my thesis work focuses on determining the operational rules used by developmental enhancers that integrate the Notch signaling pathway with other pathways. During development, the Notch signaling pathway in used to pattern cell territories involved in cell fate determination, and plays a role in differentiation. I first used a computational approach to identify a set of candidate Notch-target enhancers. From this set I carefully studied one specific enhancer from the nab gene that integrates the Notch and Bone Morphogenetic Protein (BMP) signaling pathways in the developing wing. This nab enhancer is a part of a cluster of enhancers that work together to drive the global nab expression pattern during development. Each of these enhancers drives the expected expression patterns as well as atypical expression patterns, which are silenced by adjacent enhancers. These results suggest that Notch targeted enhancers are involved in both tissue specific gene activation and gene silencing.

The implementation of Wavelength Division Multiplexing system (WDM) optical fibre transmission systems has the potential to realise this high capacity data rate exceeding 10 Tb/s. The ability to reconfigure optical networks is a desirable attribute for future metro applications where light paths can be set up or taken down dynamically as required in the network. The use of microelectronics in conjunction with photonics enables intelligence to be added to the high-speed capability of photonics, thus realising reconfigurable optical devices which can revolutionise optical telecommunications and many more application areas. In this thesis, we investigate and demonstrate the capability of Opto-VLSI processors to realise a reconfigurable WDM optical device of many functions, namely, optical multiband filtering, optical notch filtering, and reconfigurable-Optical-Add-Drop Multiplexing (ROADM). We review the potential technologies available for tunable WDM components, and discuss their advantages and disadvantages. We also develop a simple yet effective algorithm that optimises the performance of Opto-VLSI processors, and demonstrate experimentally the multi-function WDM devices employing Opto-VLSI processors. Finally, the feasibility of Opto-VLSI-based WDM devices in meeting the stringent requirements of the optical communications industry is discussed.

<p>Both Notch and the Wnt pathways are key regulators in maintaining the homeostasis in the intestine. Defects on the key tumor suppressor adenomatous polyposis coli, APC a gene in the Wnt pathway is most frequently mutated in colorectal cancer. Previous studies have indicated that there is a crosstalk between these two pathways. We investigate if there is correlation by first using bioinformatics to find Lef1/Tcf sites in several of the Notch pathway gene promoters. Bioinformatically we found that a lot of the genes contained theses sites controlled by the APC's destruction target β-catenin. By using semi quantitative PCR and western blot we found that Hes 1, Hes 7, JAG 2, MAML 1, Notch 2, NUMB, NUMBL, RFNG and LFNG was downregulated in HT29 colon cancer cells carrying a vector containing wild type APC. All but JAG 2 contains at least one Lef1/Tcf site in their promoter region. The results were verified in HT29 cells transfected with siRNA against β-catenin. We also investigated what would happen to the Lef1/Tcf target gene program of the Wnt pathway, if the Notch pathway was inhibited with the gamma-secretase inhibitor DAPT. Results showed no downregulution of β-catenin or its target gene Cyclin D1.Taken together, these results demonstrate that the Wnt pathway can be placed upstream of the Notch pathway and regulates the latter through β-catenin and the Lef1/Tcf target gene program. However, preliminary results indicate that there is no regulation of APC/β-catenin by the Notch pathway.</p>

Notch signals are required to promote T lineage commitment and development and suppress alternative cell fates in the thymus. Although the Notch activating ligand(s) in the thymus is(are) not known, studies have shown that hematopoietic progenitors are sensitive to Delta-like (DL), but not Jagged (Jag)-type ligands. In Chapter 3, I show that DL-expressing bone marrow stromal cell lines exhibit Notch ligand-independent functional heterogeneity in their capacity to support T cell development in vitro. These findings thus suggest the existence of stromal cell-derived signals that work with Notch to support T cell development. In Chapters 4 and 5, I investigated the ability of Fringe proteins to modulate Notch ligand-receptor interactions and the developmental consequences of these interactions for hematopoetic progenitors. Fringe proteins are glycosyl-transferases that enhance Notch activation by DL ligands and inhibit Notch activation by Jag ligands. In Chapter 4 I show that Lunatic Fringe (Lfng) enhances the strength of DL-mediated Notch activation to drive proliferation and expansion of early thymocytes and that DL4 and DL1 display different potencies to induce Notch-dependent outcomes. In Chapter 5, I demonstrate for the first time in a mammalian system that Lfng and Manic Fringe (Mfng) co-operate to enhance DL-Notch interactions and inhibit Jag-Notch interactions in hematopoietic stem cells. Thus, Lfng and Mfng function together to induce T cell development and inhibit B cell, myeloid and NK cell development. Collectively, these data highlight the importance of Fringe proteins in modulating the strength and specificity of Notch signaling levels during hematopoieisis.

The role that each of the Notch receptors play in controlling alveolar development and cell fate determination in the mouse mammary gland has remained unclear. By utilizing a cre-conditional constitutively active intracellular Notch1 knock-in I define, in vivo, that ectopic Notch1 activation is sufficient to inhibit ductal outgrowth, cause the formation of alveolar-like cell accumulations, and promote Elf5+/ER- cell fate, at the expense of ER+ cell fate, in the mammary gland of pubescent mice. Furthermore, ectopic Notch1 in the pregnant mammary gland is sufficient to promote the formation of pregnancy/lactation-dependent lactating adenomas. These lactating adenomas consist of differentiated secretory cells and normally regress during involution but progress into non-regressing tumours after multiple pregnancies. These lactating adenomas exhibit decapitation secretions characteristic of apocrine differentiation. Together these results suggest that Notch1 may function to promote Elf5+/ER- cell fate and may be misregulated in pregnancy-associated masses and apocrine-carcinoma of the breast in humans.

The role that each of the Notch receptors play in controlling alveolar development and cell fate determination in the mouse mammary gland has remained unclear. By utilizing a cre-conditional constitutively active intracellular Notch1 knock-in I define, in vivo, that ectopic Notch1 activation is sufficient to inhibit ductal outgrowth, cause the formation of alveolar-like cell accumulations, and promote Elf5+/ER- cell fate, at the expense of ER+ cell fate, in the mammary gland of pubescent mice. Furthermore, ectopic Notch1 in the pregnant mammary gland is sufficient to promote the formation of pregnancy/lactation-dependent lactating adenomas. These lactating adenomas consist of differentiated secretory cells and normally regress during involution but progress into non-regressing tumours after multiple pregnancies. These lactating adenomas exhibit decapitation secretions characteristic of apocrine differentiation. Together these results suggest that Notch1 may function to promote Elf5+/ER- cell fate and may be misregulated in pregnancy-associated masses and apocrine-carcinoma of the breast in humans.

Notch signals are required to promote T lineage commitment and development and suppress alternative cell fates in the thymus. Although the Notch activating ligand(s) in the thymus is(are) not known, studies have shown that hematopoietic progenitors are sensitive to Delta-like (DL), but not Jagged (Jag)-type ligands. In Chapter 3, I show that DL-expressing bone marrow stromal cell lines exhibit Notch ligand-independent functional heterogeneity in their capacity to support T cell development in vitro. These findings thus suggest the existence of stromal cell-derived signals that work with Notch to support T cell development. In Chapters 4 and 5, I investigated the ability of Fringe proteins to modulate Notch ligand-receptor interactions and the developmental consequences of these interactions for hematopoetic progenitors. Fringe proteins are glycosyl-transferases that enhance Notch activation by DL ligands and inhibit Notch activation by Jag ligands. In Chapter 4 I show that Lunatic Fringe (Lfng) enhances the strength of DL-mediated Notch activation to drive proliferation and expansion of early thymocytes and that DL4 and DL1 display different potencies to induce Notch-dependent outcomes. In Chapter 5, I demonstrate for the first time in a mammalian system that Lfng and Manic Fringe (Mfng) co-operate to enhance DL-Notch interactions and inhibit Jag-Notch interactions in hematopoietic stem cells. Thus, Lfng and Mfng function together to induce T cell development and inhibit B cell, myeloid and NK cell development. Collectively, these data highlight the importance of Fringe proteins in modulating the strength and specificity of Notch signaling levels during hematopoieisis.

Nowadays, timber is widely used in construction industry thanks to its availability and good properties. The use of solid (sawn) timber is not always proper since it is only available up to certain dimensions. Therefore, the so-called Engineered WoodProducts (EWPs) have been introduced to cope with the different design needs of structures. The Glued laminated Timber (glulam) is a type of EWPs that consists of smallsections of timber laminates glued together to form beams and columns. Glulam can be manufactured in almost any size and shape; it can also be tapered or notched. However, notching a beam at its end leads to a stress concentration at the re-entrantcorner of the notch due to the sudden change in the notched beam’s cross section. The concentration of shear and tensile stresses perpendicular to the grain can lead to a catastrophic brittle failure caused by the crack propagation from the notch corner. Crack opening due to tensile stresses perpendicular to grain is the most common failure at the notch corner and it is always taken into design consideration. However,shear component is usually exists and must be also considered in design to guarantee the safety of the structure. Currently, only the normal forces perpendicular to the beam’s axis are considered in the design of the reinforcement in design handbooks. The aim of this thesis was to study the structural behavior of notched glulam beams reinforced by adhered plywood panels and FRP. The carrying capacity of the notched glulam beams at their ends is the main subject of this thesis. In addition, a review of the notched beams design, reinforcements, and analysis theories are included. Experimental series of three point bending tests with notched glulam beams withdifferent configurations of reinforcement was carried out in lab. Deformations and forces were measured both with conventional techniques and with contact-free measurement systems - ARAMIS. On the other hand, a simple model of two dimensional plane stress element has been created of the unreinforced notchedbeam in ABAQUS. The normal and shear stresses were calculated for a horizontalpath of 100 mm in length starting from the notch tip. Afterwards, the mean stresseswere determined for the same path and have been used in calculations. The Mean Stress Approach has been adopted in the hand calculations to calculate the crack length and the failure load according to the ABAQUS model. Accordingly, the failure load was about 40 kN for the unreinforced beams. Also, Eurocode 5 has been used to calculate the failure load which gave a value of 20.2 kN for the unreinforced beams. The average maximum applied load in tests was 30 kN for the unreinforced beams while it reached about two and a half times this value for the CF-reinforced and the plywood-reinforced beams. / Tack vare sina goda egenskaper används trä i byggnadskonstruktioner i allt storeomfattning. Konstruktionsvirke (sågade trävaror) kan dock inte alltid användas pågrund av de begränsade dimensioner som finns tillgängliga. På grund av bl a dettahar ett flertal så kallade engineer wood products (EWP) utvecklats. Limträ är en typav EWP som består av sammanlimmade lameller som bygger upp tvärsnitt i balkareller pelare. Limträ kan tillverkas i nästan godtycklig storlek och form och kan enkeltförses med t ex urtag. Vid urtag i balkändar nära upplag uppstår högaspänningskoncentrationer vid urtagets horn på grund av geometrin. Koncentrationenav normalspänningar och skjuvspänningar kan leda till plötsligt brott på grund avsprickpropagering från urtagets hörn, något som måste tas hänsyn till viddimensionering. Dagens dimensioneringsmetoder är baserade på att man tar hänsyntill enbart normalspänningarna vinkelrät fiberriktningen.Målet med detta arbete har varit att studera beteendet hos limträbalkar med urtag vidupplag som förstärkts med fiberarmering eller plywood. Huvudmålet har varit attbestämma balkarnas bärförmåga, vilket skett genom att genomföra försök med olikakonfigurationer vad gäller förstärkningsmaterial och dess utformning. Vidare harolika dimensioneringsmetoder från litteraturen studerats.Kraft och förskjutning under provningarna uppmättes dels med traditionellamätmetoder, men deformationerna mättes även med beröringsfri metod, ARAMIS.En enkel tvådimensionell finit elementmodell skapades och analyserades i ABAQUSför analys av oförstärkt balk. Normalspänningar och skjuvspänningar beräknades ochmedelspänningarna längs en på förhand definierad sträcka beräknades.Medelspänningskriteriet användes sedan för att uppskatta balkens bärförmåga.Enligt FE-beräkningarna uppskattades bärförmågan för de oförstärkta balkarna till ca40 kN. Provningarna gav ett medelvärde på balkarnas bärförmåga på ca 30 kN,medan de förstärkta balkarna hade en 2,5 gånger högre bärförmåga. Skillnadenmellan FE-beräkningarna och provningarna kan förklaras med den osäkerhet somfinns vad gäller det aktuella trämaterialets egenskaper.Beräkningar enligt Eurokod 5 gav en karakteristisk bärförmåga på 20,2 kN.