Intelligent zero-day intrusion detection framework for internet of things
- Authors: Khraisat, Ansam
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: Zero-day intrusion detection system faces serious challenges as hundreds of thousands of new instances of malware are being created every day to cause harm or damage to the computer system. Cyber-attacks are becoming more sophisticated, leading to challenges in intrusion detection. There are many Intrusion Detection Systems (IDSs), which are proposed to identify abnormal activities, but most of these IDSs produce a large number of false positives and low detection accuracy. Hence, a significant quantity of false positives could generate a high-level of alerts in a short period of time as the normal activities are classified as intrusion activities. This thesis proposes a novel framework of hybrid intrusion detection system that integrates the Signature Intrusion Detection System (SIDS) with the Anomaly Intrusion Detection System (AIDS) to detect zero-day attacks with high accuracy. SIDS has been used to identify previously known intrusions, and AIDS has been applied to detect unknown zero-day intrusions. The goal of this research is to combine the strengths of each technique toward the development of a hybrid framework for the efficient intrusion detection system. A number of performance measures including accuracy, F-measure and area under ROC curve have been used to evaluate the efficacy of our proposed models and to compare and contrast with existing approaches. Extensive simulation results conducted in this thesis show that the proposed framework is capable of yielding excellent detection performance when tested with a number of widely used benchmark datasets in the intrusion detection system domain. Experiments show that the proposed hybrid IDS provides higher detection rate and lower false-positive rate in detecting intrusions as compared to the SIDS and AIDS techniques individually.
- Description: Doctor of Philosophy
- Authors: Khraisat, Ansam
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: Zero-day intrusion detection system faces serious challenges as hundreds of thousands of new instances of malware are being created every day to cause harm or damage to the computer system. Cyber-attacks are becoming more sophisticated, leading to challenges in intrusion detection. There are many Intrusion Detection Systems (IDSs), which are proposed to identify abnormal activities, but most of these IDSs produce a large number of false positives and low detection accuracy. Hence, a significant quantity of false positives could generate a high-level of alerts in a short period of time as the normal activities are classified as intrusion activities. This thesis proposes a novel framework of hybrid intrusion detection system that integrates the Signature Intrusion Detection System (SIDS) with the Anomaly Intrusion Detection System (AIDS) to detect zero-day attacks with high accuracy. SIDS has been used to identify previously known intrusions, and AIDS has been applied to detect unknown zero-day intrusions. The goal of this research is to combine the strengths of each technique toward the development of a hybrid framework for the efficient intrusion detection system. A number of performance measures including accuracy, F-measure and area under ROC curve have been used to evaluate the efficacy of our proposed models and to compare and contrast with existing approaches. Extensive simulation results conducted in this thesis show that the proposed framework is capable of yielding excellent detection performance when tested with a number of widely used benchmark datasets in the intrusion detection system domain. Experiments show that the proposed hybrid IDS provides higher detection rate and lower false-positive rate in detecting intrusions as compared to the SIDS and AIDS techniques individually.
- Description: Doctor of Philosophy
Interactions between a gall–inducing wasp Trichilogaster acaciaelongifoliae (Hymenoptera: Pteromalidae) and its host plant Acacia longifolia (Fabaceae)
- Authors: Islam, Md Rashedul
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: Sallow Wattle (Acacia longifolia subsp. longifolia) is a native Australian shrub which is an invasive weed in some parts of Australia, and internationally. A gall-forming wasp (Trichilogaster acaciaelongifoliae), also native to Australia, causes abnormal growth of tissues (galls) in Sallow Wattle. This wasp is used outside of Australia to control invasive populations of this plant species. However, in Australia, the wasp is not effective in managing the spread of Sallow Wattle. This study investigates various aspects of the relationship between the wasp and its host plant in Australian ecosystems to better understand the physiological and ecological processes involved. The study shows that this wasp is host-specific on Sallow Wattle. The feeding action of the larval wasps increase secondary plant compounds in gall tissue, which may assist the plant to defend itself chemically against other insects and microorganisms. The growth of the galls redirects resources which are otherwise used by the plant for growth and reproduction. A second insect species was found within the galls and was identified as Megastigmus sp. This second species is likely to be a parasitoid, killing the larvae of the gall-former and occupying the gall. The presence of Megastigmus sp. in Australian ecosystems may be a key factor affecting the ability of T. acaciaelongifoliae to control Sallow Wattle in its native range. The structure of galls formed by each type of gall-inducing insects is unique and the process of gall induction also varies across species. The present study has specifically examined the initiation and development of galls formed by T. acaciaelongifoliae on A. l. longifolia. Unlike other hymenopteran groups, which induce galls during oviposition, T. acaciaelongifoliae appears to form galls on A. l. longifolia via the larval feeding process. Three major stages of gall development were identified and described: induction of gall, growth and maturation of gall, and shrinking and desiccation of gall. These findings have significantly extended our current knowledge of gall induction and development by the hymenopteran group of insects. Total antioxidant capacity (TAC), total phenol (TP), and total anthocyanin (TA) were measured in galls formed by T. acaciaelongifoliae at different growth stages of galls and in other plant tissue samples of A. l. longifolia to understand the effect of gall formation on plant phytochemistry. The results indicated differences in the amounts of phytochemicals in tissue samples from galls of different growth stages of galls and between gall tissue samples and other plant samples of A. l. longifolia. The highest amount of total antioxidant capacity, total phenols and total anthocyanin were recorded in samples of early stages galls, whereas the minimum amounts of phytochemicals were in stems of A. l. longifolia. Amounts of antioxidant capacity, phenols and anthocyanin gradually declined as galls developed and larvae became less active in their feeding activity prior to pupation. It is assumed that the active feeding action of the larvae results in increased amounts of these chemicals in the early growth stages of the galls. The effect of galls formed by the wasp, T. acaciaelongifoliae on the growth and reproduction of A. l. longifolia was investigated in the native home range of both species, where the plant is invasive. Differences in the average number of phyllodes per sub-branch were found between galled and ungalled plants. Galls were also shown to affect the growth rate of branches. The number of galls correlated positively with twig mortality; and negatively with the number of seedpods per sub-branch. While galls formed by T. acaciaelongifoliae have impacts on the growth and reproduction of A. l. longifolia plants, the plant continues to invade Australian ecosystems. An experiment was conducted to investigate the host plant preference of T. acaciaelongifoliae. Ten different native host plant species (co-occurring with A. l. longifolia in the study locations) were tested in two set of experiments; a ‘free choice test’ and ‘no choice test’. The results showed that T. acaciaelongifoliae is highly host-specific on A. l. longifolia plants. Thus, it was concluded that the presence of other plant species does not explain the continued invasiveness of A. l. longifolia in Australia. A second insect species was found in the galls developed by T. acaciaelongifoliae on A. l. longifolia. The insect species has been identified as another hymenopteran from the genus Megastigmus. Since no T. acaciaelongifoliae emerged from the galls occupied by Megastigmus sp, it is proposed that Megastigmus sp. may feed upon T. acaciaelongifoliae larvae and kill them inside the galls. This might be a key factor affecting the performance of the wasp, T. acaciaelongifoliae in controlling A. l. longifolia in its native distribution. Parasitism rates of Megastigmus sp. should be investigated in future experiments.
- Description: Doctor of Philosophy
- Authors: Islam, Md Rashedul
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: Sallow Wattle (Acacia longifolia subsp. longifolia) is a native Australian shrub which is an invasive weed in some parts of Australia, and internationally. A gall-forming wasp (Trichilogaster acaciaelongifoliae), also native to Australia, causes abnormal growth of tissues (galls) in Sallow Wattle. This wasp is used outside of Australia to control invasive populations of this plant species. However, in Australia, the wasp is not effective in managing the spread of Sallow Wattle. This study investigates various aspects of the relationship between the wasp and its host plant in Australian ecosystems to better understand the physiological and ecological processes involved. The study shows that this wasp is host-specific on Sallow Wattle. The feeding action of the larval wasps increase secondary plant compounds in gall tissue, which may assist the plant to defend itself chemically against other insects and microorganisms. The growth of the galls redirects resources which are otherwise used by the plant for growth and reproduction. A second insect species was found within the galls and was identified as Megastigmus sp. This second species is likely to be a parasitoid, killing the larvae of the gall-former and occupying the gall. The presence of Megastigmus sp. in Australian ecosystems may be a key factor affecting the ability of T. acaciaelongifoliae to control Sallow Wattle in its native range. The structure of galls formed by each type of gall-inducing insects is unique and the process of gall induction also varies across species. The present study has specifically examined the initiation and development of galls formed by T. acaciaelongifoliae on A. l. longifolia. Unlike other hymenopteran groups, which induce galls during oviposition, T. acaciaelongifoliae appears to form galls on A. l. longifolia via the larval feeding process. Three major stages of gall development were identified and described: induction of gall, growth and maturation of gall, and shrinking and desiccation of gall. These findings have significantly extended our current knowledge of gall induction and development by the hymenopteran group of insects. Total antioxidant capacity (TAC), total phenol (TP), and total anthocyanin (TA) were measured in galls formed by T. acaciaelongifoliae at different growth stages of galls and in other plant tissue samples of A. l. longifolia to understand the effect of gall formation on plant phytochemistry. The results indicated differences in the amounts of phytochemicals in tissue samples from galls of different growth stages of galls and between gall tissue samples and other plant samples of A. l. longifolia. The highest amount of total antioxidant capacity, total phenols and total anthocyanin were recorded in samples of early stages galls, whereas the minimum amounts of phytochemicals were in stems of A. l. longifolia. Amounts of antioxidant capacity, phenols and anthocyanin gradually declined as galls developed and larvae became less active in their feeding activity prior to pupation. It is assumed that the active feeding action of the larvae results in increased amounts of these chemicals in the early growth stages of the galls. The effect of galls formed by the wasp, T. acaciaelongifoliae on the growth and reproduction of A. l. longifolia was investigated in the native home range of both species, where the plant is invasive. Differences in the average number of phyllodes per sub-branch were found between galled and ungalled plants. Galls were also shown to affect the growth rate of branches. The number of galls correlated positively with twig mortality; and negatively with the number of seedpods per sub-branch. While galls formed by T. acaciaelongifoliae have impacts on the growth and reproduction of A. l. longifolia plants, the plant continues to invade Australian ecosystems. An experiment was conducted to investigate the host plant preference of T. acaciaelongifoliae. Ten different native host plant species (co-occurring with A. l. longifolia in the study locations) were tested in two set of experiments; a ‘free choice test’ and ‘no choice test’. The results showed that T. acaciaelongifoliae is highly host-specific on A. l. longifolia plants. Thus, it was concluded that the presence of other plant species does not explain the continued invasiveness of A. l. longifolia in Australia. A second insect species was found in the galls developed by T. acaciaelongifoliae on A. l. longifolia. The insect species has been identified as another hymenopteran from the genus Megastigmus. Since no T. acaciaelongifoliae emerged from the galls occupied by Megastigmus sp, it is proposed that Megastigmus sp. may feed upon T. acaciaelongifoliae larvae and kill them inside the galls. This might be a key factor affecting the performance of the wasp, T. acaciaelongifoliae in controlling A. l. longifolia in its native distribution. Parasitism rates of Megastigmus sp. should be investigated in future experiments.
- Description: Doctor of Philosophy
Internationalisation of higher education curriculum : a case study in Vietnam
- Authors: Luong, Thi Phuong
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: This thesis investigated how the process of internationalisation of the curriculum (IoC) was perceived as taking place at a non-western university, namely Foreign Trade University (FTU) in Vietnam, through the development and offering of a number of jointly run programs, labelled Foreign Undergraduate Programs (FUPs). Two specific programs were examined, both of which were developed in partnership with two western universities – Colorado State University (FTU-CSU program) and London Metropolitan University (FTU-LMET program). These programs provide a range of opportunities for Vietnamese university students to experience an education that aims to reflect an international and therefore ‘broader’ context. The relationship between globalisation and internationalisation is explored and linked with the development of curriculum in higher education and internationalisation trends and strategies. Internationalisation of the curriculum, which is one of the internationalisation strategies employed by educational institutions, is investigated in terms of its interrelationship with student learning, the disciplines and academics. Engeström’s (2001) third generation Activity Theory was used as the theoretical lens for analysis of the data, which was collected via a mainly qualitative case study. Two cohorts of participants provided data through 24 interviews (seven including a joint one with program leaders/course coordinators, and 17 with academics) and 34 surveys completed by academics. The interviews/survey investigated participants’ perceptions about internationalisation and particularly IoC in relation to the two programs. Part of the significance of this study lies in the use of a number of conceptual and theoretical frameworks to extend the current body of literature beyond the main context of western higher education. An innovation in this study was the evaluation of the level of curriculum internationalisation at FTU, which was conducted using the model of curriculum internationalisation proposed by Huang (2017). Findings suggested that program managers and course coordinators worked collaboratively with their western partners to provide programs that they perceived as worthwhile in meeting the needs of the institution and the Vietnamese government agenda for internationalisation. However, academics were not generally well informed about the broader goals relating to IoC and found it challenging to accommodate the expectations with limited resources and lack of appropriate training.
- Description: Doctor of Philosophy
- Authors: Luong, Thi Phuong
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: This thesis investigated how the process of internationalisation of the curriculum (IoC) was perceived as taking place at a non-western university, namely Foreign Trade University (FTU) in Vietnam, through the development and offering of a number of jointly run programs, labelled Foreign Undergraduate Programs (FUPs). Two specific programs were examined, both of which were developed in partnership with two western universities – Colorado State University (FTU-CSU program) and London Metropolitan University (FTU-LMET program). These programs provide a range of opportunities for Vietnamese university students to experience an education that aims to reflect an international and therefore ‘broader’ context. The relationship between globalisation and internationalisation is explored and linked with the development of curriculum in higher education and internationalisation trends and strategies. Internationalisation of the curriculum, which is one of the internationalisation strategies employed by educational institutions, is investigated in terms of its interrelationship with student learning, the disciplines and academics. Engeström’s (2001) third generation Activity Theory was used as the theoretical lens for analysis of the data, which was collected via a mainly qualitative case study. Two cohorts of participants provided data through 24 interviews (seven including a joint one with program leaders/course coordinators, and 17 with academics) and 34 surveys completed by academics. The interviews/survey investigated participants’ perceptions about internationalisation and particularly IoC in relation to the two programs. Part of the significance of this study lies in the use of a number of conceptual and theoretical frameworks to extend the current body of literature beyond the main context of western higher education. An innovation in this study was the evaluation of the level of curriculum internationalisation at FTU, which was conducted using the model of curriculum internationalisation proposed by Huang (2017). Findings suggested that program managers and course coordinators worked collaboratively with their western partners to provide programs that they perceived as worthwhile in meeting the needs of the institution and the Vietnamese government agenda for internationalisation. However, academics were not generally well informed about the broader goals relating to IoC and found it challenging to accommodate the expectations with limited resources and lack of appropriate training.
- Description: Doctor of Philosophy
Investigating the configuration of a flight training device for visual flight rules navigation
- Authors: Harvey, William
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: The acquisition of pilot navigational skills utilising visual landmarks is a crucial skill that is required as part of Visual Flight Rules navigation towards obtaining a Private Pilot License. Due to the high cost of pilot training simulators, industry has identified a need for research in efficient utilisation of low-end, low cost personal compute flight simulators to assist in developing pilot skills. Analysis of the effectiveness of the use of such personal computer simulators depend on proper configuration determined by measurable errors to define simulator fidelity. To date, research has shown that the configuration of these simulators appears to have been done in an ad-hoc fashion and not in a scientific fashion. Therefore, the problem that needed to be solved was how to effectively configure such simulators. This thesis research attempted to solve this problem and present the process for effectively configuring a personal computer simulator, or flight training device, capable of successful Visual Flight Rules navigation. The simulator was configurated utilising a process that followed an interpretation of the Design Science research method, and an error correction model to determine the errors in the simulator configuration. This was done by comparing two probability distributions to measure the maximum error variable distance in order to configure a simulator suitable for the acquisition of Visual Flight Rules navigation piloting skills required for obtaining a Private Pilot Licence in Australia. This error identification method was then used to indicate simulator configuration efficiency and fidelity in order to achieve a minimum suitable configuration and setup. Further application of the findings of this research could potentially lead to the configuration of different types of non-aviation simulators, in particular Part-Task-Trainers and other training devices, including Virtual Reality Augmented Reality devices utilising various types of platforms such as Windows, Apple, and Android.
- Description: Doctor of Philosophy
- Authors: Harvey, William
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: The acquisition of pilot navigational skills utilising visual landmarks is a crucial skill that is required as part of Visual Flight Rules navigation towards obtaining a Private Pilot License. Due to the high cost of pilot training simulators, industry has identified a need for research in efficient utilisation of low-end, low cost personal compute flight simulators to assist in developing pilot skills. Analysis of the effectiveness of the use of such personal computer simulators depend on proper configuration determined by measurable errors to define simulator fidelity. To date, research has shown that the configuration of these simulators appears to have been done in an ad-hoc fashion and not in a scientific fashion. Therefore, the problem that needed to be solved was how to effectively configure such simulators. This thesis research attempted to solve this problem and present the process for effectively configuring a personal computer simulator, or flight training device, capable of successful Visual Flight Rules navigation. The simulator was configurated utilising a process that followed an interpretation of the Design Science research method, and an error correction model to determine the errors in the simulator configuration. This was done by comparing two probability distributions to measure the maximum error variable distance in order to configure a simulator suitable for the acquisition of Visual Flight Rules navigation piloting skills required for obtaining a Private Pilot Licence in Australia. This error identification method was then used to indicate simulator configuration efficiency and fidelity in order to achieve a minimum suitable configuration and setup. Further application of the findings of this research could potentially lead to the configuration of different types of non-aviation simulators, in particular Part-Task-Trainers and other training devices, including Virtual Reality Augmented Reality devices utilising various types of platforms such as Windows, Apple, and Android.
- Description: Doctor of Philosophy
Never afters : female friendship and collaboration in contemporary re-visioned fairy tales by women
- Authors: McDermott, Kirstyn
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: Antagonism among girls and women in fairy tales has been the subject of much critical and popular discussion over recent decades. Significantly less attention, however, has been paid to the frequent absence of collaborative female relationships in traditional fairy tales and their contemporary retellings. Holding re-visioned fairy tales to be a type of feminist creative praxis, this thesis investigates how mutually beneficial relationships between female characters may be constructed within such narratives. “Never Afters” is a collection of six re-visions, written as sequels to well-known fairy tales from the Western European corpus. Situated within a genre that commonly isolates female characters or foregrounds female antagonism, each re-vision employs one (or more) of five key strategies that are used by contemporary authors to imagine collaborative female relationships within retold fairy tales: inversion, insertion/deletion, expansion, fusion, and extrapolation. The exegesis contextualises my creative work and assesses the strengths and limitations of each strategy by critically examining how they are used in contemporary fairy tales by authors including Emma Donoghue, Theodora Goss, Angela Slatter, Aimee Bender, and Kelly Link. I demonstrate that expansion, fusion, and extrapolation best allow authors to introduce new female characters and fresh feminist perspectives that move away from female exceptionalism and instead foreground female collaboration and friendship as potent sources of narrative power. The exegesis further argues that the cognitive sciences, and schema theories in particular, may offer insights as to why collaborative female relationships have received such scant representation. Using case studies of my own creative praxis, I explore the ways in which female isolation and acrimony are re-inscribed in contemporary work and recommend the adoption of new frameworks through which creative writers may critically and reflexively interrogate their tacit storytelling knowledge.
- Description: Doctor of Philosophy
- Authors: McDermott, Kirstyn
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: Antagonism among girls and women in fairy tales has been the subject of much critical and popular discussion over recent decades. Significantly less attention, however, has been paid to the frequent absence of collaborative female relationships in traditional fairy tales and their contemporary retellings. Holding re-visioned fairy tales to be a type of feminist creative praxis, this thesis investigates how mutually beneficial relationships between female characters may be constructed within such narratives. “Never Afters” is a collection of six re-visions, written as sequels to well-known fairy tales from the Western European corpus. Situated within a genre that commonly isolates female characters or foregrounds female antagonism, each re-vision employs one (or more) of five key strategies that are used by contemporary authors to imagine collaborative female relationships within retold fairy tales: inversion, insertion/deletion, expansion, fusion, and extrapolation. The exegesis contextualises my creative work and assesses the strengths and limitations of each strategy by critically examining how they are used in contemporary fairy tales by authors including Emma Donoghue, Theodora Goss, Angela Slatter, Aimee Bender, and Kelly Link. I demonstrate that expansion, fusion, and extrapolation best allow authors to introduce new female characters and fresh feminist perspectives that move away from female exceptionalism and instead foreground female collaboration and friendship as potent sources of narrative power. The exegesis further argues that the cognitive sciences, and schema theories in particular, may offer insights as to why collaborative female relationships have received such scant representation. Using case studies of my own creative praxis, I explore the ways in which female isolation and acrimony are re-inscribed in contemporary work and recommend the adoption of new frameworks through which creative writers may critically and reflexively interrogate their tacit storytelling knowledge.
- Description: Doctor of Philosophy
Positive attitude change to school - Narrative inquiry into adolescent students' lived experiences
- Authors: Wojtaszek, Sylwia
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: This thesis reports on a qualitative research study that investigated adolescent students‟ experiences of positive attitude change to school. The literature review situates the research of students‟ attitude changes to school within the affective component of the multidimensional construct of student engagement and identifies this field and the phenomenon of positive attitude change to school as underresearched and under-theorised. Narrative inquiry methodology was applied in order to provide a detailed description of students‟ lived experiences and generate knowledge to fill the existing gap of how such an experience manifests itself. Eight students, who self-reported to have experienced positive attitude change to school, shared stories through in-depth semi-structured interviews of how the attitude change came about, who or what influenced it, and what meaning they attached to it in relation to its impact on their engagement and wellbeing. Students‟ attitudes to school are predominantly examined through quantitative research, whereas this study provided a unique and nuanced insight into attitude change based on the qualitative paradigm and a social constructionist view of the experience from the students‟ vantage point. Students‟ narrative accounts are compared and contrasted with each other to identify five resonant threads associated with the experience of positive attitude change to school. Data analysis suggests that positive attitude change to school has a significant impact on student engagement in learning and student wellbeing through its embodiment of perceived positive emotions associated with being at school. It consequently illustrates the relevance of broadening the understanding of such an experience to address the critical issue of disengagement in adolescent students. Key findings indicate that students develop a negative attitude to school when personal problems remain unresolved or have been insufficiently addressed within the school environment; no “helping hand” was there to assist these ambitious students who were struggling to engage in learning due to their experience of negative emotions at school. This research study has revealed that a negative attitude to school does not necessarily equate to a negative attitude to learning. Students‟ perception of the available support, both from the teachers and the services offered at school, is a critical factor in the transformation of their attitudes to school. Further, the students who participated in this study did not themselves feel that they were equipped with the required knowledge and skills to manage their personal problems effectively in order to maintain their engagement in learning. Only after having “hit rock bottom” and having sought help from outside the school environment were the students able to apply a different perspective to their circumstances that was associated with positive attitude change to school. From this research study it can be concluded that a student‟s positive attitude to school is a requirement for successful social and academic outcomes, and it is an educational goal in itself regarding the notion of developing lifelong learners. Personal problems and their impact on student engagement and wellbeing need to be acknowledged and catered for within the school environment. School support services must proactively extend a helping hand to students who have a negative attitude to school. Further, students need to develop selfefficacy regarding their personal wellbeing so that they become confident to act autonomously in solving their situations at school that are characterised by the difficult negative emotions that they are experiencing. Students‟ attitudes to school and the complexity of the multidimensional construct of student engagement need to be considered in the development of initiatives to address adolescent student disengagement and in the development of student wellbeing frameworks.
- Description: Doctor of Philosophy
- Authors: Wojtaszek, Sylwia
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: This thesis reports on a qualitative research study that investigated adolescent students‟ experiences of positive attitude change to school. The literature review situates the research of students‟ attitude changes to school within the affective component of the multidimensional construct of student engagement and identifies this field and the phenomenon of positive attitude change to school as underresearched and under-theorised. Narrative inquiry methodology was applied in order to provide a detailed description of students‟ lived experiences and generate knowledge to fill the existing gap of how such an experience manifests itself. Eight students, who self-reported to have experienced positive attitude change to school, shared stories through in-depth semi-structured interviews of how the attitude change came about, who or what influenced it, and what meaning they attached to it in relation to its impact on their engagement and wellbeing. Students‟ attitudes to school are predominantly examined through quantitative research, whereas this study provided a unique and nuanced insight into attitude change based on the qualitative paradigm and a social constructionist view of the experience from the students‟ vantage point. Students‟ narrative accounts are compared and contrasted with each other to identify five resonant threads associated with the experience of positive attitude change to school. Data analysis suggests that positive attitude change to school has a significant impact on student engagement in learning and student wellbeing through its embodiment of perceived positive emotions associated with being at school. It consequently illustrates the relevance of broadening the understanding of such an experience to address the critical issue of disengagement in adolescent students. Key findings indicate that students develop a negative attitude to school when personal problems remain unresolved or have been insufficiently addressed within the school environment; no “helping hand” was there to assist these ambitious students who were struggling to engage in learning due to their experience of negative emotions at school. This research study has revealed that a negative attitude to school does not necessarily equate to a negative attitude to learning. Students‟ perception of the available support, both from the teachers and the services offered at school, is a critical factor in the transformation of their attitudes to school. Further, the students who participated in this study did not themselves feel that they were equipped with the required knowledge and skills to manage their personal problems effectively in order to maintain their engagement in learning. Only after having “hit rock bottom” and having sought help from outside the school environment were the students able to apply a different perspective to their circumstances that was associated with positive attitude change to school. From this research study it can be concluded that a student‟s positive attitude to school is a requirement for successful social and academic outcomes, and it is an educational goal in itself regarding the notion of developing lifelong learners. Personal problems and their impact on student engagement and wellbeing need to be acknowledged and catered for within the school environment. School support services must proactively extend a helping hand to students who have a negative attitude to school. Further, students need to develop selfefficacy regarding their personal wellbeing so that they become confident to act autonomously in solving their situations at school that are characterised by the difficult negative emotions that they are experiencing. Students‟ attitudes to school and the complexity of the multidimensional construct of student engagement need to be considered in the development of initiatives to address adolescent student disengagement and in the development of student wellbeing frameworks.
- Description: Doctor of Philosophy
Random finite element method prediction and optimisation for open pit mine slope stability analysis
- Authors: Dyson, Ashley
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: Inherent soil variability can have significant effects on the stability of open-pit mine slopes. In practice, the spatial variability of materials is not commonly considered as a routine component of slope stability analysis. The process of quantifying spatially variable parameters, as well as the modelling of their behaviour is often a complex undertaking. Currently, there are no large-scale commercial software packages containing in-built methods for modelling spatial variability within the Finite Element environment. Furthermore, conventional Limit Equilibrium Methods (LEM) incorporating spatial variability are unable to consider the stress/strain characteristics of these materials. The following research seeks to accurately model the slope mechanics of spatially variable soils, adopting The Random Finite Element Method (RFEM) developed by Griffiths and Fenton (2004) to determine slope failure mechanisms and safety factors. Techniques are developed to produce a set of optimised Random Finite Element Method simulations using the Monte Carlo Method. Additionally, random field analysis techniques are investigated to compare and categorise soil parameter fluctuation, providing a direct relationship between random field properties and slope failure surfaces. Optimisation and analysis techniques are implemented to examine the effects of cross-sectional geometries and input parameter distributions on failure mechanisms, safety factors and probabilities of failure. Cross-sectional RFEM analysis is performed in the Finite Element Method (FEM) software package Abaqus, with the techniques of this research demonstrated for a large open-pit brown coal mine located in the state of Victoria, Australia. The outcome of this research is a comprehensive procedure for optimised RFEM simulation and analysis.
- Description: Doctor of Philosophy
- Authors: Dyson, Ashley
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: Inherent soil variability can have significant effects on the stability of open-pit mine slopes. In practice, the spatial variability of materials is not commonly considered as a routine component of slope stability analysis. The process of quantifying spatially variable parameters, as well as the modelling of their behaviour is often a complex undertaking. Currently, there are no large-scale commercial software packages containing in-built methods for modelling spatial variability within the Finite Element environment. Furthermore, conventional Limit Equilibrium Methods (LEM) incorporating spatial variability are unable to consider the stress/strain characteristics of these materials. The following research seeks to accurately model the slope mechanics of spatially variable soils, adopting The Random Finite Element Method (RFEM) developed by Griffiths and Fenton (2004) to determine slope failure mechanisms and safety factors. Techniques are developed to produce a set of optimised Random Finite Element Method simulations using the Monte Carlo Method. Additionally, random field analysis techniques are investigated to compare and categorise soil parameter fluctuation, providing a direct relationship between random field properties and slope failure surfaces. Optimisation and analysis techniques are implemented to examine the effects of cross-sectional geometries and input parameter distributions on failure mechanisms, safety factors and probabilities of failure. Cross-sectional RFEM analysis is performed in the Finite Element Method (FEM) software package Abaqus, with the techniques of this research demonstrated for a large open-pit brown coal mine located in the state of Victoria, Australia. The outcome of this research is a comprehensive procedure for optimised RFEM simulation and analysis.
- Description: Doctor of Philosophy
Robust Mobile Malware Detection
- Authors: Khoda, Mahbub
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: The increasing popularity and use of smartphones and hand-held devices have made them the most popular target for malware attackers. Researchers have proposed machine learning-based models to automatically detect malware attacks on these devices. Since these models learn application behaviors solely from the extracted features, choosing an appropriate and meaningful feature set is one of the most crucial steps for designing an effective mobile malware detection system. There are four categories of features for mobile applications. Previous works have taken arbitrary combinations of these categories to design models, resulting in sub-optimal performance. This thesis systematically investigates the individual impact of these feature categories on mobile malware detection systems. Feature categories that complement each other are investigated and categories that add redundancy to the feature space (thereby degrading the performance) are analyzed. In the process, the combination of feature categories that provides the best detection results is identified. Ensuring reliability and robustness of the above-mentioned malware detection systems is of utmost importance as newer techniques to break down such systems continue to surface. Adversarial attack is one such evasive attack that can bypass a detection system by carefully morphing a malicious sample even though the sample was originally correctly identified by the same system. Self-crafted adversarial samples can be used to retrain a model to defend against such attacks. However, randomly using too many such samples, as is currently done in the literature, can further degrade detection performance. This work proposed two intelligent approaches to retrain a classifier through the intelligent selection of adversarial samples. The first approach adopts a distance-based scheme where the samples are chosen based on their distance from malware and benign cluster centers while the second selects the samples based on a probability measure derived from a kernel-based learning method. The second method achieved a 6% improvement in terms of accuracy. To ensure practical deployment of malware detection systems, it is necessary to keep the real-world data characteristics in mind. For example, the benign applications deployed in the market greatly outnumber malware applications. However, most studies have assumed a balanced data distribution. Also, techniques to handle imbalanced data in other domains cannot be applied directly to mobile malware detection since they generate synthetic samples with broken functionality, making them invalid. In this regard, this thesis introduces a novel synthetic over-sampling technique that ensures valid sample generation. This technique is subsequently combined with a dynamic cost function in the learning scheme that automatically adjusts minority class weight during model training which counters the bias towards the majority class and stabilizes the model. This hybrid method provided a 9% improvement in terms of F1-score. Aiming to design a robust malware detection system, this thesis extensively studies machine learning-based mobile malware detection in terms of best feature category combination, resilience against evasive attacks, and practical deployment of detection models. Given the increasing technological advancements in mobile and hand-held devices, this study will be very useful for designing robust cybersecurity systems to ensure safe usage of these devices.
- Description: Doctor of Philosophy
- Authors: Khoda, Mahbub
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: The increasing popularity and use of smartphones and hand-held devices have made them the most popular target for malware attackers. Researchers have proposed machine learning-based models to automatically detect malware attacks on these devices. Since these models learn application behaviors solely from the extracted features, choosing an appropriate and meaningful feature set is one of the most crucial steps for designing an effective mobile malware detection system. There are four categories of features for mobile applications. Previous works have taken arbitrary combinations of these categories to design models, resulting in sub-optimal performance. This thesis systematically investigates the individual impact of these feature categories on mobile malware detection systems. Feature categories that complement each other are investigated and categories that add redundancy to the feature space (thereby degrading the performance) are analyzed. In the process, the combination of feature categories that provides the best detection results is identified. Ensuring reliability and robustness of the above-mentioned malware detection systems is of utmost importance as newer techniques to break down such systems continue to surface. Adversarial attack is one such evasive attack that can bypass a detection system by carefully morphing a malicious sample even though the sample was originally correctly identified by the same system. Self-crafted adversarial samples can be used to retrain a model to defend against such attacks. However, randomly using too many such samples, as is currently done in the literature, can further degrade detection performance. This work proposed two intelligent approaches to retrain a classifier through the intelligent selection of adversarial samples. The first approach adopts a distance-based scheme where the samples are chosen based on their distance from malware and benign cluster centers while the second selects the samples based on a probability measure derived from a kernel-based learning method. The second method achieved a 6% improvement in terms of accuracy. To ensure practical deployment of malware detection systems, it is necessary to keep the real-world data characteristics in mind. For example, the benign applications deployed in the market greatly outnumber malware applications. However, most studies have assumed a balanced data distribution. Also, techniques to handle imbalanced data in other domains cannot be applied directly to mobile malware detection since they generate synthetic samples with broken functionality, making them invalid. In this regard, this thesis introduces a novel synthetic over-sampling technique that ensures valid sample generation. This technique is subsequently combined with a dynamic cost function in the learning scheme that automatically adjusts minority class weight during model training which counters the bias towards the majority class and stabilizes the model. This hybrid method provided a 9% improvement in terms of F1-score. Aiming to design a robust malware detection system, this thesis extensively studies machine learning-based mobile malware detection in terms of best feature category combination, resilience against evasive attacks, and practical deployment of detection models. Given the increasing technological advancements in mobile and hand-held devices, this study will be very useful for designing robust cybersecurity systems to ensure safe usage of these devices.
- Description: Doctor of Philosophy
Special needs, special play? Examining the agency of children with impairments in play-based learning in a special school
- Authors: Claughton, Amy
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: Play is an inherent part of childhood, often cast as an innate behaviour of children. Over the years, play has been scrutinised by theorists, researchers and educators alike in their attempts to understand how children engage in play, the role of play in development and how to identify, define and measure play. For children with impairments, play is frequently subjected to surveillance and compared to that of children whose development is considered typical. This thesis interrogates the play-based learning experiences of five children who attended a special educational school in rural Victoria, Australia. It examines the experiences that these children had in play and how teacher actions and responses enabled and supported their engagement in play-based learning. The theoretical framework for this study draws on critical ethnography underpinned by disability studies. Disability studies recognises the social model of disability, in which disability is a social construction. Using this model, impairment is distinct and separate from disability. In this study, socially constructed barriers that confront children in their play are identified as being created by attitudes, structures and environments (Bishop et al., 1999). These barriers are overlaid by the psycho-emotional dimensions of disability (C. Thomas, 1999) in an effort to represent the experiences of children as shaped by the actions and responses of others. This thesis introduces a new analytic tool in the learning portal framework. The learning portal framework aims to provide a platform through which teacher actions and responses can be analysed to understand how children are enabled to access play-based learning. The findings of this study indicate that children with impairments play in complex and nuanced ways. They show purpose in their play, are able to self-initiate, and independently investigate play-based learning experiences. Adult actions and responses often enable children with impairments to engage in play by offering opportunities and pathways for exploration. Indirect adult facilitation in play supports children’s ability to act in play with individuality and determination.
- Description: Doctor of Philosophy
- Authors: Claughton, Amy
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: Play is an inherent part of childhood, often cast as an innate behaviour of children. Over the years, play has been scrutinised by theorists, researchers and educators alike in their attempts to understand how children engage in play, the role of play in development and how to identify, define and measure play. For children with impairments, play is frequently subjected to surveillance and compared to that of children whose development is considered typical. This thesis interrogates the play-based learning experiences of five children who attended a special educational school in rural Victoria, Australia. It examines the experiences that these children had in play and how teacher actions and responses enabled and supported their engagement in play-based learning. The theoretical framework for this study draws on critical ethnography underpinned by disability studies. Disability studies recognises the social model of disability, in which disability is a social construction. Using this model, impairment is distinct and separate from disability. In this study, socially constructed barriers that confront children in their play are identified as being created by attitudes, structures and environments (Bishop et al., 1999). These barriers are overlaid by the psycho-emotional dimensions of disability (C. Thomas, 1999) in an effort to represent the experiences of children as shaped by the actions and responses of others. This thesis introduces a new analytic tool in the learning portal framework. The learning portal framework aims to provide a platform through which teacher actions and responses can be analysed to understand how children are enabled to access play-based learning. The findings of this study indicate that children with impairments play in complex and nuanced ways. They show purpose in their play, are able to self-initiate, and independently investigate play-based learning experiences. Adult actions and responses often enable children with impairments to engage in play by offering opportunities and pathways for exploration. Indirect adult facilitation in play supports children’s ability to act in play with individuality and determination.
- Description: Doctor of Philosophy
Stress resilience : meaning, measurement, and the effects of physical activity
- Authors: O’Donohue, Josephine
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: In rodent models of human behaviour, physical activity builds stress resilience. In contrast, human studies physical activity and stress resilience have been limited, and when investigated, provided mixed results. These inconsistencies may be due to the ambiguous use of the term stress resilience in human studies, making it difficult to quantify. Therefore, I aimed to assess the effect of physical activity on stress resilience in humans, after first evaluating operational definitions of stress resilience. Initially, I evaluated the use of stress resilience across the literature to provide a definition that is consistent with the research base (Chapter 2). I subsequently defined stress resilience as an active process of adapting to unpredictable and uncontrollable stimuli. In Chapter 3, I systematically reviewed measures previously used to capture stress resilience in humans, including trait-based questionnaires, as well as affective and cardiorespiratory responses to stressful conditions. In Study 1 (Chapter 4) of this dissertation, I then assessed the convergent validity of these stress resilience measures , including the Brief Resilience Scale and the Connor-Davidson Resilience Scale, as well as various responses (i.e., affective balance, systolic blood pressure, rate pressure product, and multiple indices of heart rate variability) to three stressor conditions (i.e., no stress, auditory startles, and stressful video clips). Results of Study 1 indicated that no measure captured all elements of stress resilience, although some indices of heart rate variability were related to changes in affective balance and systolic blood pressure was related to the Brief Resilience Scale. Across two studies, I then evaluated the effect of physical activity on stress resilience using the measures from Study 1. Through a cross-sectional study (Study 2, Chapter 5), I found no difference between active participants (n = 16) and less active participants (n = 14) across stress resilience measures. Additionally, in Study 3 (Chapter 6), I found that an 8-week moderate physical activity intervention had no effect on these stress resilience measures in 14 participants from desk-based occupations. I did, however, find an increase in mood and reduction in systolic blood pressure post-intervention, compared to pre-intervention scores. I also discussed the feasibility of various recruitment techniques, intervention purity and adherence, as well as stress resilience measurement protocols for future intervention studies. Overall, this dissertation has provided a critical evaluation of the use and measurement of stress resilience, with findings indicating that physical activity may not enhance stress resilience in humans. I discuss differences in my findings, compared to rodent research, including the potential effects of environment enrichment and increased severity of measurement protocols in animal models. I also discuss limitations of stress resilience conceptualisation and provide suggestions for future research to navigate these challenges.
- Description: Doctor of Philosophy
- Authors: O’Donohue, Josephine
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: In rodent models of human behaviour, physical activity builds stress resilience. In contrast, human studies physical activity and stress resilience have been limited, and when investigated, provided mixed results. These inconsistencies may be due to the ambiguous use of the term stress resilience in human studies, making it difficult to quantify. Therefore, I aimed to assess the effect of physical activity on stress resilience in humans, after first evaluating operational definitions of stress resilience. Initially, I evaluated the use of stress resilience across the literature to provide a definition that is consistent with the research base (Chapter 2). I subsequently defined stress resilience as an active process of adapting to unpredictable and uncontrollable stimuli. In Chapter 3, I systematically reviewed measures previously used to capture stress resilience in humans, including trait-based questionnaires, as well as affective and cardiorespiratory responses to stressful conditions. In Study 1 (Chapter 4) of this dissertation, I then assessed the convergent validity of these stress resilience measures , including the Brief Resilience Scale and the Connor-Davidson Resilience Scale, as well as various responses (i.e., affective balance, systolic blood pressure, rate pressure product, and multiple indices of heart rate variability) to three stressor conditions (i.e., no stress, auditory startles, and stressful video clips). Results of Study 1 indicated that no measure captured all elements of stress resilience, although some indices of heart rate variability were related to changes in affective balance and systolic blood pressure was related to the Brief Resilience Scale. Across two studies, I then evaluated the effect of physical activity on stress resilience using the measures from Study 1. Through a cross-sectional study (Study 2, Chapter 5), I found no difference between active participants (n = 16) and less active participants (n = 14) across stress resilience measures. Additionally, in Study 3 (Chapter 6), I found that an 8-week moderate physical activity intervention had no effect on these stress resilience measures in 14 participants from desk-based occupations. I did, however, find an increase in mood and reduction in systolic blood pressure post-intervention, compared to pre-intervention scores. I also discussed the feasibility of various recruitment techniques, intervention purity and adherence, as well as stress resilience measurement protocols for future intervention studies. Overall, this dissertation has provided a critical evaluation of the use and measurement of stress resilience, with findings indicating that physical activity may not enhance stress resilience in humans. I discuss differences in my findings, compared to rodent research, including the potential effects of environment enrichment and increased severity of measurement protocols in animal models. I also discuss limitations of stress resilience conceptualisation and provide suggestions for future research to navigate these challenges.
- Description: Doctor of Philosophy
Student mobility and transition : setting your compass for success
- Authors: Murrell, Kerry
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: With increasing levels of student mobility within Victorian schools, many educational settings experience frequent changes to their student population. These changes are often met with an ad hoc array of practices implemented by schools in an attempt to adequately manage them. This thesis addresses the impact of student mobility on an educational community and its stakeholders in Victoria, Australia. The research was undertaken in five Victorian government schools that encompassed diverse geographical locations and socio-economic profiles. Key stakeholders include: school principals, teachers and education support staff, mobile students, parents/carers of mobile students, non-mobile students and their families. Each group offered a unique perspective regarding student mobility and transition processes. Participants in this study were involved in interviews and focus groups, and completed a questionnaire. Socio-economic status was identified as a predominant factor in student mobility for both families and schools. This was evidenced by high levels of often unpredictable mobility in socio-economically disadvantaged and significantly disadvantaged participating schools. The participating non-disadvantaged school experienced mobility related specifically to perceived academic gain or parental promotion. Regardless of socio-economic status, each group was reliant on other stakeholders to be successful. No stakeholder groups stood alone as being able to successfully navigate the process of mobility and transition independently. This study, through the thematic analysis of the data collected, has uncovered many actionable and achievable recommendations for families, schools and the education system itself both within Victoria and nationwide. The participants in this research clearly indicated a need for a more strategic and planned approach to mobility. Educational communities must respond proactively in order to provide optimal academic, social and emotional outcomes for students in these circumstances.
- Description: Doctor of Philosophy
- Authors: Murrell, Kerry
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: With increasing levels of student mobility within Victorian schools, many educational settings experience frequent changes to their student population. These changes are often met with an ad hoc array of practices implemented by schools in an attempt to adequately manage them. This thesis addresses the impact of student mobility on an educational community and its stakeholders in Victoria, Australia. The research was undertaken in five Victorian government schools that encompassed diverse geographical locations and socio-economic profiles. Key stakeholders include: school principals, teachers and education support staff, mobile students, parents/carers of mobile students, non-mobile students and their families. Each group offered a unique perspective regarding student mobility and transition processes. Participants in this study were involved in interviews and focus groups, and completed a questionnaire. Socio-economic status was identified as a predominant factor in student mobility for both families and schools. This was evidenced by high levels of often unpredictable mobility in socio-economically disadvantaged and significantly disadvantaged participating schools. The participating non-disadvantaged school experienced mobility related specifically to perceived academic gain or parental promotion. Regardless of socio-economic status, each group was reliant on other stakeholders to be successful. No stakeholder groups stood alone as being able to successfully navigate the process of mobility and transition independently. This study, through the thematic analysis of the data collected, has uncovered many actionable and achievable recommendations for families, schools and the education system itself both within Victoria and nationwide. The participants in this research clearly indicated a need for a more strategic and planned approach to mobility. Educational communities must respond proactively in order to provide optimal academic, social and emotional outcomes for students in these circumstances.
- Description: Doctor of Philosophy
Techniques for the reverse engineering of banking malware
- Authors: Black, Paul
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: Malware attacks are a significant and frequently reported problem, adversely affecting the productivity of organisations and governments worldwide. The well-documented consequences of malware attacks include financial loss, data loss, reputation damage, infrastructure damage, theft of intellectual property, compromise of commercial negotiations, and national security risks. Mitiga-tion activities involve a significant amount of manual analysis. Therefore, there is a need for automated techniques for malware analysis to identify malicious behaviours. Research into automated techniques for malware analysis covers a wide range of activities. This thesis consists of a series of studies: an anal-ysis of banking malware families and their common behaviours, an emulated command and control environment for dynamic malware analysis, a technique to identify similar malware functions, and a technique for the detection of ransomware. An analysis of the nature of banking malware, its major malware families, behaviours, variants, and inter-relationships are provided in this thesis. In doing this, this research takes a broad view of malware analysis, starting with the implementation of the malicious behaviours through to detailed analysis using machine learning. The broad approach taken in this thesis differs from some other studies that approach malware research in a more abstract sense. A disadvantage of approaching malware research without domain knowledge, is that important methodology questions may not be considered. Large datasets of historical malware samples are available for countermea-sures research. However, due to the age of these samples, the original malware infrastructure is no longer available, often restricting malware operations to initialisation functions only. To address this absence, an emulated command and control environment is provided. This emulated environment provides full control of the malware, enabling the capabilities of the original in-the-wild operation, while enabling feature extraction for research purposes. A major focus of this thesis has been the development of a machine learn-ing function similarity method with a novel feature encoding that increases feature strength. This research develops techniques to demonstrate that the machine learning model trained on similarity features from one program can find similar functions in another, unrelated program. This finding can lead to the development of generic similar function classifiers that can be packaged and distributed in reverse engineering tools such as IDA Pro and Ghidra. Further, this research examines the use of API call features for the identi-fication of ransomware and shows that a failure to consider malware analysis domain knowledge can lead to weaknesses in experimental design. In this case, we show that existing research has difficulty in discriminating between ransomware and benign cryptographic software. This thesis by publication, has developed techniques to advance the disci-pline of malware reverse engineering, in order to minimize harm due to cyber-attacks on critical infrastructure, government institutions, and industry.
- Description: Doctor of Philosophy
- Authors: Black, Paul
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: Malware attacks are a significant and frequently reported problem, adversely affecting the productivity of organisations and governments worldwide. The well-documented consequences of malware attacks include financial loss, data loss, reputation damage, infrastructure damage, theft of intellectual property, compromise of commercial negotiations, and national security risks. Mitiga-tion activities involve a significant amount of manual analysis. Therefore, there is a need for automated techniques for malware analysis to identify malicious behaviours. Research into automated techniques for malware analysis covers a wide range of activities. This thesis consists of a series of studies: an anal-ysis of banking malware families and their common behaviours, an emulated command and control environment for dynamic malware analysis, a technique to identify similar malware functions, and a technique for the detection of ransomware. An analysis of the nature of banking malware, its major malware families, behaviours, variants, and inter-relationships are provided in this thesis. In doing this, this research takes a broad view of malware analysis, starting with the implementation of the malicious behaviours through to detailed analysis using machine learning. The broad approach taken in this thesis differs from some other studies that approach malware research in a more abstract sense. A disadvantage of approaching malware research without domain knowledge, is that important methodology questions may not be considered. Large datasets of historical malware samples are available for countermea-sures research. However, due to the age of these samples, the original malware infrastructure is no longer available, often restricting malware operations to initialisation functions only. To address this absence, an emulated command and control environment is provided. This emulated environment provides full control of the malware, enabling the capabilities of the original in-the-wild operation, while enabling feature extraction for research purposes. A major focus of this thesis has been the development of a machine learn-ing function similarity method with a novel feature encoding that increases feature strength. This research develops techniques to demonstrate that the machine learning model trained on similarity features from one program can find similar functions in another, unrelated program. This finding can lead to the development of generic similar function classifiers that can be packaged and distributed in reverse engineering tools such as IDA Pro and Ghidra. Further, this research examines the use of API call features for the identi-fication of ransomware and shows that a failure to consider malware analysis domain knowledge can lead to weaknesses in experimental design. In this case, we show that existing research has difficulty in discriminating between ransomware and benign cryptographic software. This thesis by publication, has developed techniques to advance the disci-pline of malware reverse engineering, in order to minimize harm due to cyber-attacks on critical infrastructure, government institutions, and industry.
- Description: Doctor of Philosophy
Telling a story – managing impressions about corporate social responsibility
- Authors: Paynter, Merryn
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: Today, an increasing number of companies are being held accountable by stakeholders for their impact on the environment and on society. Hence, failure to address stakeholder concerns can have dire consequences for companies, threatening their social licence-to-operate. To retain stakeholder support, companies must communicate to stakeholders how their concerns are being addressed, and this includes making disclosures about Corporate Social Responsibility (CSR). Existing literature focuses on explaining the reasons for the uptake of CSR reporting, and why companies make CSR disclosures. Presently, to date, there has been only limited research on the way that companies use CSR reporting to manage impressions, and how this differs across industries. This study is unique because it uses constructive-interpretive, qualitative storytelling research methods to examine CSR reporting, and to investigate companies’ motivations for making CSR disclosures. In this thesis, multi-level narrative research was conducted on the annual, CSR, and integrated reports produced by three Australian companies: BHP, Westpac, and Westfield between 1992 and 2017. These companies represent very different industry sectors, and were chosen to provide an understanding of the similarities and differences in the development of storytelling practices in their CSR reporting. Significant events in company reports are substantiated by newspaper articles published in the Sydney Morning Herald. These significant events are used to study episodic changes in companies’ strategic organisational storytelling responses. This study found that companies use explicit and implied storytelling strategies to convey meanings about CSR using both visual and textual language. A conceptual framework is developed which presents organisational storytelling as a process and illustrates how companies construct and tell stories about CSR. Several implications were identified from this research, key amongst them being the ability of stakeholders to determine companies’ underlying motives for creating their particular CSR stories. From a company perspective, the importance of management’s understanding of the implications of poorly-executed storytelling is demonstrated, highlighting the consequent potential for stakeholders to misinterpret CSR disclosures and form adverse opinions of companies’ actions, despite positive intentions
- Description: Doctor of Philosophy
- Authors: Paynter, Merryn
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: Today, an increasing number of companies are being held accountable by stakeholders for their impact on the environment and on society. Hence, failure to address stakeholder concerns can have dire consequences for companies, threatening their social licence-to-operate. To retain stakeholder support, companies must communicate to stakeholders how their concerns are being addressed, and this includes making disclosures about Corporate Social Responsibility (CSR). Existing literature focuses on explaining the reasons for the uptake of CSR reporting, and why companies make CSR disclosures. Presently, to date, there has been only limited research on the way that companies use CSR reporting to manage impressions, and how this differs across industries. This study is unique because it uses constructive-interpretive, qualitative storytelling research methods to examine CSR reporting, and to investigate companies’ motivations for making CSR disclosures. In this thesis, multi-level narrative research was conducted on the annual, CSR, and integrated reports produced by three Australian companies: BHP, Westpac, and Westfield between 1992 and 2017. These companies represent very different industry sectors, and were chosen to provide an understanding of the similarities and differences in the development of storytelling practices in their CSR reporting. Significant events in company reports are substantiated by newspaper articles published in the Sydney Morning Herald. These significant events are used to study episodic changes in companies’ strategic organisational storytelling responses. This study found that companies use explicit and implied storytelling strategies to convey meanings about CSR using both visual and textual language. A conceptual framework is developed which presents organisational storytelling as a process and illustrates how companies construct and tell stories about CSR. Several implications were identified from this research, key amongst them being the ability of stakeholders to determine companies’ underlying motives for creating their particular CSR stories. From a company perspective, the importance of management’s understanding of the implications of poorly-executed storytelling is demonstrated, highlighting the consequent potential for stakeholders to misinterpret CSR disclosures and form adverse opinions of companies’ actions, despite positive intentions
- Description: Doctor of Philosophy
The biopsychosocial impact of Autism on families and the contribution of solar irradiance to its aetiology
- Authors: Syed, Somayya
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: Autism Spectrum Disorder (ASD) is a lifelong disorder of unknown aetiology. A recent hypothesis is that a lack of Vitamin D is implicated in either the aetiology or maintenance of ASD. The human body synthesises Vitamin D from Ultraviolet-B (UVB) radiation found in sunlight. It follows that greater exposure to sunlight hours may be related to decreased rates of ASD. There are no interventions that target the causes of ASD rather therapies address either its symptoms or its comorbidities. ASD not only affects individuals, it also has an impact on their families. Family members have experienced social, occupational and personal costs associated with their child’s ASD which can result in parental separation or divorce. While researchers have established some of the factors which contribute to the impact on families, this research has not addressed families living in regional areas nor have empirical studies used domain-specific scales. The aims in this thesis were: Study 1) to determine whether the prevalence rates of ASD vary as a function of exposure to sunlight by reviewing reported prevalence rates by latitude where, the greater the distance from the equator, the higher the expected prevalence rates; Study 2) to conduct interviews with parents and caregivers of children with ASD who live in a regional area to determine the factors which affect them and those which might protect them; and Study 3) use the interview data to develop domain specific measures and test a model of living with a child with ASD. The results of Study 1 revealed that there is an increase in the prevalence of ASD as distance from the equator increases lending some support to the hypothesis that Vitamin D is implicated in ASD. The 16 interviews conducted in Study 2 revealed seven themes: impact on finances; family life; child’s health and behaviour, and schooling; child’s future; limited support, and regional living. In Study 3, with 178 participants, domain-specific scales were developed to test a model of the impact of living with a child with ASD. Resilience manifested by social support and coping strategies, explained 54% of the variance in impact of living with a child with ASD which, was operationalised by financial and relationship costs, social impact and feelings. Family life as assessed in this thesis, is significantly impacted by living with a child with ASD. The implications of these findings are discussed, especially around the need for greater exposure to outdoor activities and hence sunlight for children with ASD, more regional facilities and assistance for families, the importance of educational interventions for the public as well as enhancing levels of family resilience, as operationalised by support and coping strategies. Limitations of the studies and future research are discussed.
- Description: Doctor of Philosophy
- Authors: Syed, Somayya
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: Autism Spectrum Disorder (ASD) is a lifelong disorder of unknown aetiology. A recent hypothesis is that a lack of Vitamin D is implicated in either the aetiology or maintenance of ASD. The human body synthesises Vitamin D from Ultraviolet-B (UVB) radiation found in sunlight. It follows that greater exposure to sunlight hours may be related to decreased rates of ASD. There are no interventions that target the causes of ASD rather therapies address either its symptoms or its comorbidities. ASD not only affects individuals, it also has an impact on their families. Family members have experienced social, occupational and personal costs associated with their child’s ASD which can result in parental separation or divorce. While researchers have established some of the factors which contribute to the impact on families, this research has not addressed families living in regional areas nor have empirical studies used domain-specific scales. The aims in this thesis were: Study 1) to determine whether the prevalence rates of ASD vary as a function of exposure to sunlight by reviewing reported prevalence rates by latitude where, the greater the distance from the equator, the higher the expected prevalence rates; Study 2) to conduct interviews with parents and caregivers of children with ASD who live in a regional area to determine the factors which affect them and those which might protect them; and Study 3) use the interview data to develop domain specific measures and test a model of living with a child with ASD. The results of Study 1 revealed that there is an increase in the prevalence of ASD as distance from the equator increases lending some support to the hypothesis that Vitamin D is implicated in ASD. The 16 interviews conducted in Study 2 revealed seven themes: impact on finances; family life; child’s health and behaviour, and schooling; child’s future; limited support, and regional living. In Study 3, with 178 participants, domain-specific scales were developed to test a model of the impact of living with a child with ASD. Resilience manifested by social support and coping strategies, explained 54% of the variance in impact of living with a child with ASD which, was operationalised by financial and relationship costs, social impact and feelings. Family life as assessed in this thesis, is significantly impacted by living with a child with ASD. The implications of these findings are discussed, especially around the need for greater exposure to outdoor activities and hence sunlight for children with ASD, more regional facilities and assistance for families, the importance of educational interventions for the public as well as enhancing levels of family resilience, as operationalised by support and coping strategies. Limitations of the studies and future research are discussed.
- Description: Doctor of Philosophy
The effects of norepinephrine on the proliferation, lipid-uptake and mRNA expression of inflammatory markers in vascular smooth muscle cells
- Authors: Anesi, Jack
- Date: 2020
- Type: Text , Thesis , Master of Applied Science
- Full Text:
- Description: Background: Cardiovascular disease (CVD) is the leading, global cause of death. Elevated levels of norepinephrine (NE) are associated with CVDs such as coronary heart disease with atherosclerosis as the underlying mechanism. Oxidised low-density lipoprotein (OxLDL) has been shown to play an integral role in the formation of atherosclerosis within the vasculature. Previous studies suggest a decrease in NE by renal denervation is associated with enhanced atherosclerosis in mice and NE has anti-inflammatory effects. Therefore, we hypothesised that NE may protect against atherosclerosis. This study aimed to investigate the effects of NE on cellular proliferation, OxLDL uptake and mRNA expression of inflammatory markers in mouse aortic vascular smooth muscle cells (VSMCs), a key cell type involved in atherosclerosis. Methods: Mouse aortic VSMCs were cultured and treated with NE for three consecutive days. Cell proliferation was measured using the trypan blue exclusion and MTS proliferation assays. VSMCs were exposed to fluorescence-labelled OxLDL in the presence or absence of NE for 24 hours. Cellular uptake of fluorescence-labelled OxLDL was visualised by confocal microscopy and analysed for mean fluorescence intensity using ImageJ. To investigate the involvement of NE receptors, the
- Description: Masters
- Authors: Anesi, Jack
- Date: 2020
- Type: Text , Thesis , Master of Applied Science
- Full Text:
- Description: Background: Cardiovascular disease (CVD) is the leading, global cause of death. Elevated levels of norepinephrine (NE) are associated with CVDs such as coronary heart disease with atherosclerosis as the underlying mechanism. Oxidised low-density lipoprotein (OxLDL) has been shown to play an integral role in the formation of atherosclerosis within the vasculature. Previous studies suggest a decrease in NE by renal denervation is associated with enhanced atherosclerosis in mice and NE has anti-inflammatory effects. Therefore, we hypothesised that NE may protect against atherosclerosis. This study aimed to investigate the effects of NE on cellular proliferation, OxLDL uptake and mRNA expression of inflammatory markers in mouse aortic vascular smooth muscle cells (VSMCs), a key cell type involved in atherosclerosis. Methods: Mouse aortic VSMCs were cultured and treated with NE for three consecutive days. Cell proliferation was measured using the trypan blue exclusion and MTS proliferation assays. VSMCs were exposed to fluorescence-labelled OxLDL in the presence or absence of NE for 24 hours. Cellular uptake of fluorescence-labelled OxLDL was visualised by confocal microscopy and analysed for mean fluorescence intensity using ImageJ. To investigate the involvement of NE receptors, the
- Description: Masters
The Melbourne art scene and the Victorian artists’ society 1870-2020
- Authors: Williams, Graeme
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: This thesis is a socio-cultural history, utilising the Victorian Artists’ Society as a longitudinal case study to look at the extent to which it has serviced the professional needs of artists. The Victorian Artists’ Society, formed in 1870, is the oldest organisation representing the visual arts in Victoria and, as such, is an appropriate vehicle to examine the discourse between history and the construction of cultural values in the visual arts in Melbourne. The Melbourne ‘art scene’ has existed since Victoria’s proclamation as a separate colony in 1851. During the greater part of this time, the Victorian Artists’ Society functioned as a meeting and an exhibition space for visual artists. Although it is Australia’s second oldest continuous organisation representing visual artists, the Society has been uncontroversial and largely ignored by academics as a focus of research in its own right. Notwithstanding, the two groups subject of the most academic attention and research, namely the Australian Academy of Art and the Contemporary Art Society, were announced and formed within its walls, with many of their key proponents members of the Society. Researching extensive archival records, this thesis explores the relationship that existed between the Society and Melbourne’s art community throughout its 150-year history. It historically interrogates to what extent the Society has been a harbinger for change. Through a study of organisations and events impacting the Melbourne art scene, the thesis argues the relevance of the Society to professional and amateur artists today. It reviews how societies, and clubs in general, once servicing the needs of all artists, have evolved into a more general function, and what role the emergence of the commercial gallery system played as the main platform for the success of the artist. Finally, it examines what sustains, inspires, and informs contemporary professional artists working in Melbourne today.
- Description: Doctor of Philosophy
- Authors: Williams, Graeme
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: This thesis is a socio-cultural history, utilising the Victorian Artists’ Society as a longitudinal case study to look at the extent to which it has serviced the professional needs of artists. The Victorian Artists’ Society, formed in 1870, is the oldest organisation representing the visual arts in Victoria and, as such, is an appropriate vehicle to examine the discourse between history and the construction of cultural values in the visual arts in Melbourne. The Melbourne ‘art scene’ has existed since Victoria’s proclamation as a separate colony in 1851. During the greater part of this time, the Victorian Artists’ Society functioned as a meeting and an exhibition space for visual artists. Although it is Australia’s second oldest continuous organisation representing visual artists, the Society has been uncontroversial and largely ignored by academics as a focus of research in its own right. Notwithstanding, the two groups subject of the most academic attention and research, namely the Australian Academy of Art and the Contemporary Art Society, were announced and formed within its walls, with many of their key proponents members of the Society. Researching extensive archival records, this thesis explores the relationship that existed between the Society and Melbourne’s art community throughout its 150-year history. It historically interrogates to what extent the Society has been a harbinger for change. Through a study of organisations and events impacting the Melbourne art scene, the thesis argues the relevance of the Society to professional and amateur artists today. It reviews how societies, and clubs in general, once servicing the needs of all artists, have evolved into a more general function, and what role the emergence of the commercial gallery system played as the main platform for the success of the artist. Finally, it examines what sustains, inspires, and informs contemporary professional artists working in Melbourne today.
- Description: Doctor of Philosophy
The Millers : historical analysis of an early Australian colonial family
- Authors: Barrera, Jennifer
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: In July 1823, a family originally from Derry-Londonderry, Ireland, embarked on the long journey from Chatham Dockyards, along with the first despatch of troops from the 40th Regiment, to the colony of New South Wales. Lieutenant Henry Miller would become the first commandant of the Moreton Bay penal settlement. But by August 1825, Lieutenant Miller had been replaced—in effect, dismissed—and the family relocated to Van Diemen’s Land. This thesis explores the growing importance of family history in the twenty-first century as a popular pursuit for engaging with and writing history. It highlights family history’s potential for historical inquiry and its capacity to unpack settler colonial history and the role of the individual in Empire. It offers fresh historical perspectives on Australia’s colonial experiment. The research uses the combined methodologies of microhistory, biography and family history to recover the lives of Henry Miller, his wife Jane, sons Henry and Mars, his father the Reverend Miller, as well as, the diverse and interconnected lives of Captain John Townson, his brother Robert, convict Sarah Griggs, and her children. As a number of scholarly histories in the last decade have shown, family history as an approach for engaging with the past continues to gain attention globally and offers powerful benefits to those who engage with it, for the family historian and academic historian alike. The six core chapters that comprise this thesis demonstrate the importance of family history research to deepening our understanding of the past and its capacity to change the way we think and write about the past. This thesis aims to make a substantial and original contribution to Australian colonial history by recovering powerful lost voices and identities, and connecting the past with the present in a more intimate and accessible way through the exploration of a colonial family.
- Description: Doctor of Philosophy
- Authors: Barrera, Jennifer
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: In July 1823, a family originally from Derry-Londonderry, Ireland, embarked on the long journey from Chatham Dockyards, along with the first despatch of troops from the 40th Regiment, to the colony of New South Wales. Lieutenant Henry Miller would become the first commandant of the Moreton Bay penal settlement. But by August 1825, Lieutenant Miller had been replaced—in effect, dismissed—and the family relocated to Van Diemen’s Land. This thesis explores the growing importance of family history in the twenty-first century as a popular pursuit for engaging with and writing history. It highlights family history’s potential for historical inquiry and its capacity to unpack settler colonial history and the role of the individual in Empire. It offers fresh historical perspectives on Australia’s colonial experiment. The research uses the combined methodologies of microhistory, biography and family history to recover the lives of Henry Miller, his wife Jane, sons Henry and Mars, his father the Reverend Miller, as well as, the diverse and interconnected lives of Captain John Townson, his brother Robert, convict Sarah Griggs, and her children. As a number of scholarly histories in the last decade have shown, family history as an approach for engaging with the past continues to gain attention globally and offers powerful benefits to those who engage with it, for the family historian and academic historian alike. The six core chapters that comprise this thesis demonstrate the importance of family history research to deepening our understanding of the past and its capacity to change the way we think and write about the past. This thesis aims to make a substantial and original contribution to Australian colonial history by recovering powerful lost voices and identities, and connecting the past with the present in a more intimate and accessible way through the exploration of a colonial family.
- Description: Doctor of Philosophy
The optimization of loop-mediated isothermal amplification (LAMP) as a diagnostic tool for low-density, asymptomatic malaria infections
- Authors: Surrao, Leanna
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: Current diagnostic tools for malaria lack the sensitivity to identify individuals with low-density infections. Asymptomatic low-density infections are common in malaria endemic regions and these individuals provide an important reservoir of infection that enables transmission to mosquitoes. Failure to detect these individuals threatens the global health goal of malaria elimination. Loop-mediated isothermal amplification (LAMP) is a technique to amplify DNA and has the potential to diagnose these individuals. The LAMP assay was assessed in a field study in rural Vietnam. 5421 samples were collected and tested with a commercially available LAMP assay in Commune Health Care Centres in Binh Phuoc and Dak Nong Provinces. 101 positive LAMP cases (asymptomatic, smear, and RDT negative) were identified, with the proportion of positives ranging from 0.18% and 3.25% across five communes. In order for LAMP to be used as a screening tool, it must be cost effective and have a workflow suitable for minimally trained end users. To achieve this, an in-house LAMP assay was developed and compared to PCR. The assay was combined with instrument detection to simplify decision making for the end user and improve sensitivity. The in-house assay was as sensitive as the PCR assay and cost US$0.60 per reaction compared to US$3.57 for PCR and US$8.23 for the commercial LAMP. An integrated single cartridge, called T1, was assessed to further simplify this workflow of sample preparation, LAMP amplification and detection. Further development of the cartridge and the assay will be required for future deployment. The LAMP assay is suitable for detection of low density infections in asymptomatically infected individuals in field settings and has the potential for cost effective population based screening.
- Description: Doctor of Philosophy
- Authors: Surrao, Leanna
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: Current diagnostic tools for malaria lack the sensitivity to identify individuals with low-density infections. Asymptomatic low-density infections are common in malaria endemic regions and these individuals provide an important reservoir of infection that enables transmission to mosquitoes. Failure to detect these individuals threatens the global health goal of malaria elimination. Loop-mediated isothermal amplification (LAMP) is a technique to amplify DNA and has the potential to diagnose these individuals. The LAMP assay was assessed in a field study in rural Vietnam. 5421 samples were collected and tested with a commercially available LAMP assay in Commune Health Care Centres in Binh Phuoc and Dak Nong Provinces. 101 positive LAMP cases (asymptomatic, smear, and RDT negative) were identified, with the proportion of positives ranging from 0.18% and 3.25% across five communes. In order for LAMP to be used as a screening tool, it must be cost effective and have a workflow suitable for minimally trained end users. To achieve this, an in-house LAMP assay was developed and compared to PCR. The assay was combined with instrument detection to simplify decision making for the end user and improve sensitivity. The in-house assay was as sensitive as the PCR assay and cost US$0.60 per reaction compared to US$3.57 for PCR and US$8.23 for the commercial LAMP. An integrated single cartridge, called T1, was assessed to further simplify this workflow of sample preparation, LAMP amplification and detection. Further development of the cartridge and the assay will be required for future deployment. The LAMP assay is suitable for detection of low density infections in asymptomatically infected individuals in field settings and has the potential for cost effective population based screening.
- Description: Doctor of Philosophy
The regional trifecta: Entrepreneurs, managers and community leaders - an Ethnographic typology of leaders collaborating in a Regional Vicrorian Community
- Authors: Isham, Amy
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: This doctoral thesis explores a socioeconomic model for understanding and analysing leadership in the regional area of Horsham and its hinterland communities. This thesis critiques accepted models of regional development policy and leadership theory and in doing so argues for a new approach emphasising the roles that leaders adopt to achieve goals. These roles comprise the entrepreneur, manager and community leader that this thesis terms the regional trifecta model of leadership. This is a model that explores the ways that leaders attain mutuality within social and economic eco-systems in order to achieve long-term regional economic sustainability and liveability for residents. This doctoral study uses a critical qualitative ethnographic exploration of Horsham and its surrounding region drawing on researcher, the informant participant’s observations from a wide range of industries and social backgrounds. This thesis discusses themes of policy barriers to environmentally sustainable entrepreneurship, social ostracism of female leaders, a sense of futility in bureaucratic compliance, passive and unsupportive communities, tempered with the critical hope of social enterprise and potential partnerships. In examining these themes the thesis argues that entrepreneurs are overwhelmingly values driven. It also asserts that they experience barriers of unreliable labour and unsupportive external partnerships. Managers are also strongly values driven and can experience many barriers from internal partnerships within their own organisations. Community leaders are values driven and struggle against the barriers of bureaucracy with the organisations they partner with. The thesis provides a new contribution to the literature. This includes a critique of psycho-social approaches to leadership through role-based explorations that emphasise a collective responsibility for success within an eco-system. It also examines the types of people that become leaders and their motivations in regional Victoria. From this emerges a discussion about the tension between formal governance and power structures and the informal agency of leaders. The recommendations that emerge from this research are that policy-makers, local, state and federal governments acknowledge and support the role of existing informal leaders and the significant social and economic benefit they bring to regional Victoria.
- Description: Doctor of Philosophy
- Authors: Isham, Amy
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: This doctoral thesis explores a socioeconomic model for understanding and analysing leadership in the regional area of Horsham and its hinterland communities. This thesis critiques accepted models of regional development policy and leadership theory and in doing so argues for a new approach emphasising the roles that leaders adopt to achieve goals. These roles comprise the entrepreneur, manager and community leader that this thesis terms the regional trifecta model of leadership. This is a model that explores the ways that leaders attain mutuality within social and economic eco-systems in order to achieve long-term regional economic sustainability and liveability for residents. This doctoral study uses a critical qualitative ethnographic exploration of Horsham and its surrounding region drawing on researcher, the informant participant’s observations from a wide range of industries and social backgrounds. This thesis discusses themes of policy barriers to environmentally sustainable entrepreneurship, social ostracism of female leaders, a sense of futility in bureaucratic compliance, passive and unsupportive communities, tempered with the critical hope of social enterprise and potential partnerships. In examining these themes the thesis argues that entrepreneurs are overwhelmingly values driven. It also asserts that they experience barriers of unreliable labour and unsupportive external partnerships. Managers are also strongly values driven and can experience many barriers from internal partnerships within their own organisations. Community leaders are values driven and struggle against the barriers of bureaucracy with the organisations they partner with. The thesis provides a new contribution to the literature. This includes a critique of psycho-social approaches to leadership through role-based explorations that emphasise a collective responsibility for success within an eco-system. It also examines the types of people that become leaders and their motivations in regional Victoria. From this emerges a discussion about the tension between formal governance and power structures and the informal agency of leaders. The recommendations that emerge from this research are that policy-makers, local, state and federal governments acknowledge and support the role of existing informal leaders and the significant social and economic benefit they bring to regional Victoria.
- Description: Doctor of Philosophy
The regulatory effects of CD161 and MAIT cells
- Authors: Meredith, Tobias
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: Mucosal associated invariant T (MAIT) cells are connected with the potential regulation of anti-tumour responses, although their role in this regulation is poorly defined. In cancer, the relative frequency of MAIT cells has an impact on patient outcome, although how this impact is mediated is not known. Therefore, we have carefully modulated the frequency of MAIT cells within cultures and assessed the effect this has on the anti-tumour functions of important immune cells such as NK and conventional T cells. We identified that changes in MAIT cell frequency can significantly impact the ability of NK cells to become activated and produce proinflammatory cytokines. Interestingly, changes in MAIT cell frequency do not impact conventional T cell activation, but can alter pro-inflammatory cytokine expression. We also identified trends that suggest alterations in MAIT cell frequency may suppress a broad range of cytokines produced within the PBMC pool. The thesis also examined the potential regulatory impact of the cell surface molecule CD161 on T cells (particularly MAIT cells). Several distinctive characteristics have been identified that provides a broader understanding of the effect ligating and blocking this molecule can have. We have demonstrated that interaction with CD161 can promote activation and affect cytokine and perforin expression by MAIT cells. Conventional T cells are also affected, specifically their cytokine expression and activation. Lastly, we also performed several pilot studies, which identified changes in the expression of some genes of interest (e.g. IL-13, IL-5) and raised the possibility that the products of these genes could also be affected. Taken together, our research indicates that MAIT cell frequency can have significant effects on the anti-tumour roles of other immune cells. Additionally, we have furthered the understanding of which anti-tumour functions CD161 interaction can affect. CD161 has the potential to be used as an immunotherapeutic target in cancer patients, but more knowledge is required to determine the host of potential functions CD161 may affect. We suggest that further study is required, particularly in determining the effect CD161 ligation and blocking can have on cytokine output on a range of cells, including MAIT cells.
- Description: Doctor of Philosophy
- Authors: Meredith, Tobias
- Date: 2020
- Type: Text , Thesis , PhD
- Full Text:
- Description: Mucosal associated invariant T (MAIT) cells are connected with the potential regulation of anti-tumour responses, although their role in this regulation is poorly defined. In cancer, the relative frequency of MAIT cells has an impact on patient outcome, although how this impact is mediated is not known. Therefore, we have carefully modulated the frequency of MAIT cells within cultures and assessed the effect this has on the anti-tumour functions of important immune cells such as NK and conventional T cells. We identified that changes in MAIT cell frequency can significantly impact the ability of NK cells to become activated and produce proinflammatory cytokines. Interestingly, changes in MAIT cell frequency do not impact conventional T cell activation, but can alter pro-inflammatory cytokine expression. We also identified trends that suggest alterations in MAIT cell frequency may suppress a broad range of cytokines produced within the PBMC pool. The thesis also examined the potential regulatory impact of the cell surface molecule CD161 on T cells (particularly MAIT cells). Several distinctive characteristics have been identified that provides a broader understanding of the effect ligating and blocking this molecule can have. We have demonstrated that interaction with CD161 can promote activation and affect cytokine and perforin expression by MAIT cells. Conventional T cells are also affected, specifically their cytokine expression and activation. Lastly, we also performed several pilot studies, which identified changes in the expression of some genes of interest (e.g. IL-13, IL-5) and raised the possibility that the products of these genes could also be affected. Taken together, our research indicates that MAIT cell frequency can have significant effects on the anti-tumour roles of other immune cells. Additionally, we have furthered the understanding of which anti-tumour functions CD161 interaction can affect. CD161 has the potential to be used as an immunotherapeutic target in cancer patients, but more knowledge is required to determine the host of potential functions CD161 may affect. We suggest that further study is required, particularly in determining the effect CD161 ligation and blocking can have on cytokine output on a range of cells, including MAIT cells.
- Description: Doctor of Philosophy