Developing Immunotherapy Strategies for Cancer Treatment

The goal of this thesis was to develop potent tumour cell vaccines that can be used as an effective strategy for cancer treatment. Allogeneic tumour cell vaccines hold great promise for cancer treatment. Cytokine modification has been proven effective in enhancing the immunogenicity of tumour cell vaccines. This work here shows that modification of the allogeneic K1735 cells to express the immunostimulatory cytokines GM-CSF, IL-12 or IFN-ɣ, however, was not effective in augmenting the immunogenicity of the vaccine and irradiated cytokine-modified vaccines could not protect animals from autologous tumour challenge. These data are in agreement with recent literature. Similar results were obtained when K1735 cells were modified to express heat shock proteins. Analysis of the injection site of irradiated K1735 vaccine cells demonstrated that clearance of the K1735 cells from the injection site correlated well with the induction of proinflammatory cytokines and infiltration by non-specific effector cells such as NK cells. FMG-induced fusion was next investigated as a novel and effective way of releasing tumour antigens from allogeneic vaccine cells in an immunostimulatory fashion. Expression of the Vesicular Stomatitis Virus G glycoprotein by K1735 or B16 cells lead to the formation of extensive syncytia in vitro. Vaccination of mice with irradiated 2-day fusing allogeneic K1735 or syngeneic B16 cells showed no significant therapeutic benefit relative to irradiated unfused cells. Interestingly, vaccination of mice with a hybrid K1735/B16 fusing vaccine repeatedly lead to significant protective and therapeutic immunity against a B16 challenge. Overall, VSV-G mediated syncitial death was shown to be a highly immunogenic event that promotes the induction of potent specific antitumour immunity in the context of allogeneic vaccines. The mechanism of immunogenicity of fusing hybrid vaccines was investigated. Generation of long-term human allogeneic fusing tumour cell vaccines for translation of this work into clinical application was next investigated. A human melanoma cell line stably transduced with the gene for a hyperfusogenic form of the Gibbon ape leukemia virus FMG gene was generated. The Tet-On system of transcriptional control was employed to control gene expression and thus GALV-mediated fusion. Very high levels of fusion could be obtained following the addition of doxocycline in culture. This cell line could form the basis of human melanoma fusing vaccine

Decoupling method for parallel Delaunay two-dimensional mesh generation

Parallel mesh generation procedures that are based on geometric domain decompositions require the permanent separators to be of good quality (in terms of their angles and length), in order to maintain the mesh quality. The Medial Axis Domain Decomposition, an innovative geometric domain decomposition procedure that addresses this problem, is introduced. The Medial Axis domain decomposition is of high quality in terms of the formed angles, and provides separators of small size, and also good work-load balance. It presents for the first time a decomposition method suitable for parallel meshing procedures that are based on geometric domain decompositions.;The Decoupling Method for parallel Delaunay 2D mesh generation is a highly efficient and effective parallel procedure, able to generate billions of elements in a few hundred of seconds, on distributed memory machines. Our mathematical formulation introduces the notion of the decoupling path, which guarantees the decoupling property, and also the quality and conformity of the Delaunay submeshes. The subdomains are meshed independently, and as a result, the method eliminates the communication and the synchronization during the parallel meshing. A method for shielding small angles is introduced, so that the decoupled parallel Delaunay algorithm can be applied on domains with small angles. Moreover, I present the construction of a sizing function, that encompasses an existing sizing function and also geometric features and small angles. The decoupling procedure can be used for parallel graded Delaunay mesh generation, controlled by the sizing function

Quality and presence of behaviour change techniques in mobile apps for the Mediterranean diet:a content analysis of Android Google Play and Apple Store apps

Smartphone apps might represent an opportunity to promote adherence to the Mediterranean diet (MedDiet). This study aimed to evaluate the quality of commercially available apps for the MedDiet and the presence of behavioural change techniques (BCTs) used by these apps. A systematic search was conducted on the Apple App and Google Play stores in November 2021. Apps were included if they provided information on the MedDiet or if their objective was to promote a healthy lifestyle through adherence to the MedDiet. Eligible apps were independently evaluated by two reviewers with regard to their quality (engagement, functionality, aesthetics and information quality) using the 5-point Mobile App Rating Scale (MARS; with higher scores indicating higher quality), and the presence of BCTs using an established 26-item BCT taxonomy. Of the 55 analysed apps, 52 (94.5%) were free, 50 (90.9%) provided recipe ideas, 29 (52.7%) provided meal plans, and 22 (40%) provided information on the health benefits of the MedDiet. The overall quality mean MARS score was 2.84 (standard deviation (SD) = 0.42), with functionality being the highest scored MARS domain (mean = 3.58, SD = 0.44) and engagement the lowest (mean = 2.29, SD = 0.61). The average number of BCTs in the analysed apps was 2.3 (SD = 1.4; range: 0–6 per app). The number of BCTs was positively correlated with app information quality (r(rho) = 0.269, p = 0.047), overall MARS score (r(rho) = 0.267, p = 0.049), app subjective quality (r(rho) = 0.326, p = 0.015) and app-specific quality (r(rho) = 0.351, p = 0.009). These findings suggest that currently available apps might provide information on the MedDiet, but the incorporation of more BCTs is warranted to maximise the potential for behaviour change towards the MedDiet

Distributed maze exploration using multiple agents and optimal goal assignment

Robotic exploration has long captivated researchers aiming to map complex environments efficiently. Techniques such as potential fields and frontier exploration have traditionally been employed in this pursuit, primarily focusing on solitary agents. Recent advancements have shifted towards optimizing exploration efficiency through multiagent systems. However, many existing approaches overlook critical real-world factors, such as broadcast range limitations, communication costs, and coverage overlap. This paper addresses these gaps by proposing a distributed maze exploration strategy (CU-LVP) that assumes constrained broadcast ranges and utilizes Voronoi diagrams for better area partitioning. By adapting traditional multiagent methods to distributed environments with limited broadcast ranges, this study evaluates their performance across diverse maze topologies, demonstrating the efficacy and practical applicability of the proposed method. The code and experimental results supporting this study are available in the following repository: https://github.com/manouslinard/multiagent-exploration/.Comment: 11 pages, 9 figure

Arts education offered by Greek Universities to future pre-school and primary school teachers

The arts education of generalist teachers in pre-school and primary schools seems to be a matter of great importance, because it is they who mainly practice arts education in school with children up to the age of 12. The purpose of this study is to describe and evaluate the arts education offered to pre-service pre-school and primary school teachers in the departments of education of all universities in Greece. The data were collected from two sources. First, data on the characteristics of the arts courses examined were collected from university documents on the syllabus of every department in the study. Second, a questionnaire was used to collect data on what the students at the examined departments believed about the arts education they were getting. The study showed that the arts education offered in Greek departments of education has developed in a peculiar manner and has problematic aspects. Even today, it is lacking in quantity, of a lower standard than other courses, and with an orientation that either is more mechanical or more theoretical than it should be. Both the analysis of the documents and of the students’ views highlight changes that seem to be necessary to qualitatively and quantitatively improve the arts education and training provided in the departments examined

Greek kindergarten children’s motivation for reading

The aim of the present study was to investigate Greek kindergarten children’s reading motivation and their gender differences in reading motivation during kindergarten attendance. The sample of the present study consisted of 100 kindergarten children enrolled in public schools in Crete. The “Me and my reading profile” (MMRP) reading motivation tool was used. The MMRP was adjusted to Greek and was given to sample children in the beginning and at the end of the school year. Data analysis conducted with exploratory and confirmatory factor analysis revealed a 5-scale factorial structure in children’s reading motivation. Results showed that kindergarteners enhanced their reading motivation throughout the school year in the 3 out of the 5 extracted factors, while significant differences were found in the degree of reading motivation improvement between boys and girls. The results are important because they present data related to children’s reading motivation development at the first stages of literacy acquisition and are useful for making specific suggestions about educational practice and policy in Greece.The aim of the present study was to investigate Greek kindergarten children’s reading motivation and their gender differences in reading motivation during kindergarten attendance. The sample of the present study consisted of 100 kindergarten children enrolled in public schools in Crete. The “Me and my reading profile” (MMRP) reading motivation tool was used. The MMRP was adjusted to Greek and was given to sample children in the beginning and at the end of the school year. Data analysis conducted with exploratory and confirmatory factor analysis revealed a 5-scale factorial structure in children’s reading motivation. Results showed that kindergarteners enhanced their reading motivation throughout the school year in the 3 out of the 5 extracted factors, while significant differences were found in the degree of reading motivation improvement between boys and girls. The results are important because they present data related to children’s reading motivation development at the first stages of literacy acquisition and are useful for making specific suggestions about educational practice and policy in Greece