In this study, the effects of different plant growth regulators on regeneration responses of various lentil explants through direct and indirect organogenesis and through somatic embryogenesis from calli and cell suspension cultures were investigated. Shoot regeneration was obtained in low frequencies from longitudinal embryonic axis explants and nodal buds of epicotyls, however whole plant regeneration was unsuccessful. Conditions provided for indirect organogenesis resulted only in swelling of hypocotyls and root directed ends of internodes and weak callus formation on leaves which were followed by tissue browning and necrosis. In somatic embryogenesis studies, the explants longitudinal embryonic axis and cotyledonary petioles produced soft and friable calli on MS media with Gamborg&rsquo / s vitamins supplemented with 0.75mg/L 2,4-D+0.5mg/L BA. The highest average number of embryos per explant, 12.36 was observed on media containing 0.75mg/L BA +0.5mg/L 2,4-D for cotyledonary petiole explants, whereas 3mg/L BA+1mg/L NAA was the only hormone combination that allowed embryo development to some extent, in both explants. Somatic callus failed to regenerate despite globular embryo formation and embryo development to some extent. Combination of sonication treatment with Agrobacterium transformation of three lentil explants / cotyledonary nodes, half cotyledons and cotyledonary nodes with intact shoots, had no effect on the improvement of transient gus gene expression on explants. Sonication treatment was also unable to form localized wounds on the petiole axils. The best gus gene expression on the axil region was obtained when cotyledonary nodes and KYRT1 strain were used in combination with vacuum infiltration and scalpel wounding of the axils. Gradual selection and repeated removal of regenerated shoots between selection cycles increased the number of gus expressing shoots significantly. The regenerated shoots were grafted on root stocks and whole plant regeneration was achieved in greenhouse conditions. By the use of the optimized Agrobacterium-mediated transformation protocol, 4 independent lines were obtained with 2.3% transformation efficiency. Southern blot analysis confirmed the integration of the gus gene into the genome of lentil plants. T0 plants were fertile and all plants showed Mendelian segregation of the gus gene in 3:1 ratio to their progenies except one line which carries three copies of the gene. Reverse transcription PCR has confirmed the expression of the genes in T0 and T1 generations. T0 plants and the following three generations strongly expressed gus gene uniformly in their tissues and the PCR amplifications of both gus and npt-II genes was successful through generations.

<p>In the environment of the 3:rd generation Internet based on peer-to-peer architecture, well-trusted methods must exist to establish a secure environment. One main issue is the possibility to verify that a node actually is who it claims to be (authentication). Establishment of authentication between nodes in a peer-to-peer environment where nodes are exchanging information directly with each other requires more planning than in a typical client-server environment where the authentication methods are server-based. The peer-to-peer applications described in this report use authentication methods based on central authorities as well as solutions without central authorities. </p><p>Lack of standards in the way peer-to-peer systems should communicate and apply security lead to a variety of “local” communication and security solutions. These local solutions make different applications incompatible with each other, meaning that a peer using one application will not be able to communicate and exchange information with other peers using some other application.</p>

Accurate detection of the spread of cancer is critical for planning the best treatment strategy for a patient. Currently, an invasive sentinel lymph node biopsy is commonly used to detect metastases after a primary tumor is detected. This procedure results in patient morbidity, requires weeks of waiting, and is prone to sampling error. This dissertation presents new developments in an emerging biomedical imaging modality – photoacoustic imaging – and their application to improving the detection of metastases in the lymphatic system in a metastatic mouse model of squamous cell carcinoma of the oral cavity. Label-free spectroscopic photoacoustic imaging is demonstrated to detect hypoxia that results from the development of sub-millimeter cancer foci in the lymph node. In order to improve the sensitivity to micrometastases, molecularly-activated plasmonic nanosensers which are targeted to the epidermal growth factor receptor are introduced. The nanosensors are demonstrated to detect metastases consisting of only a few tens of cells. Improvements to spectroscopic photoacoustic imaging are then demonstrated by selecting imaging wavelengths based on the spectral properties of the optical absorbers. Finally, a new contrast agent – silica-coated gold nanoplates – are used to map the sentinel lymph node with high contrast. The final result is a set of tools that can be used to noninvasively detect micrometastases and improve molecular photoacoustic imaging. / text

The development of hybridoma technology nearly forty years ago set the foundation for the use of antibodies in the life sciences. Subsequent advances in recombinant DNA technology have allowed us to adapt antibody genes to various screening systems, greatly increasing the throughput and specialized applications for which these complex biomolecules can be adapted. While selection systems are a powerful tool for discovery and evolution, they can be slow and prone to unintended biases. We see computational approaches as an efficient process for rapid discovery and engineering of antibodies. This is particularly relevant for biodefense and emerging infectious disease applications, for which time is a valuable commodity. In the first chapter of this work, we examine computational protocols for ‘supercharging’ proteins. This process resurfaces the target protein, adding charged moieties to impart specialized functions such as thermoresistance and cell penetration. Current algorithms for resurfacing proteins are static, treating each mutation as an event within a vacuum. The net result is that while several variants can be created, each must be tested experimentally to ensure the resultant protein is functional. In many cases, the designed proteins were severely impaired or incapable of folding. We hypothesize that a more dynamic approach, keeping an eye on energetics and the consequences of mutations will yield a more efficient and robust method for supercharging, successfully adding charges to proteins while minimizing deleterious effects. We continue on this theme applying the successful algorithm to supercharging antibodies for increased function. Utilizing the MS2 model biosensor system, we rationally engineer charges onto the surface of an antibody fragment, increasing thermoresistance, minimizing destabilizing effects, and in some cases actually increasing affinity. Finally, we apply next-generation sequencing approaches to the rapid discovery of antibodies directed against the Zaire Ebolavirus species. We utilize a local immunization strategy to generate a polarized antibody repertoire that is then sequenced to provide a database of antigen-specific variants. This repertoire is probed in silico and individual antibodies selected for analysis, bypassing time- and resource-consuming selection experiments. / text

Transport through nanostructures is studied at the many-body level using exact diagonalization and nonequilibrium Green's functions. Organic molecular junctions are a particular focus because of their technological promise. Work is presented regarding: (1) A π-electron model of organic molecular junctions developed using effective field theory; (2) series transmission and transmission node structure in interacting systems; (3) the effect of interactions on quantum interference and thermoelectricity in polycyclic junctions; and (4) nanoscale transport calculations using self-consistent statistical ensembles.

A lot of research has been done concerning the internationalization process of companies. However, researchers have identified a new type of firm that is leapfrogging and is operating internationally right after inception. These companies are Born Globals. We are interested in this trend and the purpose of this research is to understand the strategic behaviour of Born Globals. Therefore, we have done qualitative research on these companies and we will focus on their pre-internationalization steps, their key drivers and their relation to the home market. We have found three case companies, who have helped us in our understandings and we have made several conclusions, regarding their strategic behaviour.

Aims: To describe use of post-operative radiation for endometrial cancer in Ontario. To identify system-related and patient-related factors affecting access to this treatment. Materials and Methods: We performed a retrospective population-based cohort study of patients with surgically resected endometrial cancer in the Canadian province of Ontario between 1992-2003. Patients with evidence of incurable cancer at diagnosis or previous cancer diagnosis were excluded. We used multiple logistic regression to assess patient and system factors affecting radiation use. We controlled for disease-related and treatment-related factors: histology, surgical staging, type of hysterectomy and peritoneal biopsy. We applied a mixed model to account for clustering of data by operating hospital. Results: 9,411 women comprised the study cohort. The median age was 63 years. 26.2% received adjuvant radiation. The proportion of patients receiving radiation varied between cancer centre catchment areas from 18.0% to 34.3% (median 26.3%). In multivariate analysis, older patients were more likely to receive radiation up to the age of 80 (p<.0001). Patients who lived further from regional cancer centres were less likely to receive radiation (p=.0210). Patients who had their surgery during longer prevailing wait times at regional cancer centres were less likely to receive radiation (p=.0441). There was a 2.7-fold variation in the odds of radiation use between cancer centre catchments (p<.0001). Management at a comprehensive gynecologic oncology centre was associated with use of radiation for patients who had surgical staging of lymph nodes. Year of diagnosis and neighborhood income quintile did not significantly affect the use of radiation. Conclusions: There is wide variation in use of radiation for endometrial cancer in Ontario. There is evidence that system factors unrelated to patient’s needs affect use of adjuvant radiation for endometrial cancer in Ontario. Age is a key patient-related factor affecting radiation use. / Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2009-08-07 22:02:37.308

The aim of this thesis was to investigate the prognostic role of the proliferation markers cyclin B1 and Phosphorylated Histone 3 (PPH3) in breast cancer (BC). In paper I we used an experimental study design, we compared women dying early from their BC with women free from relapse more than eight years after initial diagnosis. All women had stage I, node-negative and hormone receptor positive disease. None had received adjuvant chemotherapy. We found that low-risk node negative patients with high expression of cyclin B1 had a significantly worse outcome than patients with low expression of cyclin B1. In paper II a population-based case control study was performed to further investigate the prognostic value of cyclin B1. One hundred and ninety women who died from BC were defined as cases and 190 women alive at the time for the corresponding case’s death were defined as controls. Inclusion criteria were tumor size 50 mm, no lymph node metastases, and no adjuvant chemotherapy. Two investigators evaluated the stainings independently. Cyclin B1 was found to be a prognostic factor for BC death that could identify high-risk patients with a good to very good reproducibility. Paper III aimed to investigate the role of proliferation in male breast cancer (MBC). One hundred and ninety-seven MBC tumors were stained for cyclin A, B1, D1 and Ki67. Overexpression of cyclin A and B1 and elevated mitotic count were predictive of breast cancer death. Ki67 was re-evaluated and different cut-offs were used, but no prognostic value could be demonstrated. On the other hand high levels of cyclin D1 were associated with better outcome in MBC. In paper IV we applied the immunohistochemichal panel suggested from international guidelines to the same patient material as in paper II, to discriminate luminal A from luminal B BC. We wanted to evaluate if different cut-off values of Ki67, cyclin A or B1 could more clearly separate luminal A from B. Cyclin A, B1 and Ki67 (cut-off 20%) could detect difference in outcome between these subtypes with cyclin A showing greater prognostic value. The aim of paper V was to examine the prognostic role of PPH3 compared to the proliferation markers Ki67, cyclin A and cyclin B1 with focus on ER positive disease. PPH3 was found to be a prognostic factor for breast cancer death but in the multivariate analysis including all proliferation markers, only cyclin A remained a prognostic factor. Finally, we conclude that both cyclin B1 and PPH3 are prognostic factors for breast cancer death, but are outperformed by cyclin A in ER positive patients. In male breast cancer prognostic factors need to be further studied.

This thesis proposes an integrated artificial neural network based approach to classify the position of a wireless device in an indoor protected area. Our experiments are conducted in two different types of interference affected indoor locations. We found that the environment greatly influences the received signal strength. We realized the need of incorporating a complexity measure of the Wi-Fi signal as additional information in our localization algorithm. The inputs to the integrated artificial neural network were comprised of an integer dimension representation and a fractional dimension representation of the Wi-Fi signal. The integer dimension representation consisted of the raw signal strength, whereas the fractional dimension consisted of a variance fractal dimension of the Wi-Fi signal. The results show that the proposed approach performed 8.7% better classification than the “one dimensional input” ANN approach, achieving an 86% correct classification rate. The conventional Trilateration method achieved only a 47.97% correct classification rate.

Network coding refers to the implementation of coding methods to utilize network connections more efficiently. Network coding is commonly researched in the information theory field, but very little research is being done on the physical implementation thereof. One exception is COPE where network coding is implemented in wireless networks for unicast transmission sessions. In this dissertation, we discuss the physical arrangement of wireless nodes to form topologies suitable for the implementation of network coding. We implement linear network coding in wireless ad hoc networks for multicast transmission sessions. We calculate the areas in which each wireless node must be located for a specific network coding suitable topology to be formed. The identified topologies are simulated in OPNET Modeler and then implemented on a six node testbed, to analyse the effect of implementing network coding in these topologies. We provide results indicating the trade-off between reduced network load and higher end-to-end delay when our developed network coding algorithm is active in the respective topologies. The results indicate that the developed network coding scheme will produce better overall performance when implemented in sensor networks or highly congested ad hoc networks. / Thesis (M.Ing. (Computer and Electronical Engineering))--North-West University, Potchefstroom Campus, 2011.