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Multitrait successional forest dynamics enable diverse competitive coexistence
No full textTo explain diversity in forests, niche theory must show how multiple plant species coexist while competing for the same resources. Although successional processes are widespread in forests, theoretical work has suggested that differentiation in successional strategy allows only a few species stably to coexist, including only a single shade tolerant. However, this conclusion is based on current niche models, which encode a very simplified view of plant communities, suggesting that the potential for niche differentiation has remained unexplored. Here, we show how extending successional niche models to include features common to all vegetation—height-structured competition for light under a prevailing disturbance regime and two trait-mediated tradeoffs in plant function—enhances the diversity of species that can be maintained, including a diversity of shade tolerants. We identify two distinct axes of potential niche differentiation, corresponding to the traits leaf mass per unit leaf area and height at maturation. The first axis allows for coexistence of different shade tolerances and the second axis for coexistence among species with the same shade tolerance. Addition of this second axis leads to communities with a high diversity of shade tolerants. Niche differentiation along the second axis also generates regions of trait space wherein fitness is almost equalized, an outcome we term “evolutionarily emergent near-neutrality.” For different environmental conditions, our model predicts diverse vegetation types and trait mixtures, akin to observations. These results indicate that the outcomes of successional niche differentiation are richer than previously thought and potentially account for mixtures of traits and species observed in forests worldwide.10 page(s
The formation of new romantic relationships after breast cancer
No full textEmpirical thesis.Bibliography: pages 129-135.Chapter 1. Introduction -- Chapter 2. Dating concerns among women with breast cancer or with genetic breast cancer susceptibility : a review and meta-synthesis -- Chapter 3. Romantic dating after breast cancer : a qualitative study -- Chapter 4. Factors associated with relationship formation difficulties in women with breast cancer -- Chapter 5. Development and acceptance of the Dating After The Experience : Breast Cancer (DATE-BC) online intervention -- Chapter 6. Discussion -- Appendices.While many un-partnered women consider romantic 'dating' to be a key priority after breast cancer, these women report significant dating-related barriers and concerns. This thesis investigates women's experiences of romantic relationship formation after breast cancer, and presents a novel intervention to help women navigate dating during cancer survivorship.Chapter 2 reviews the current literature regarding dating concerns among women with breast cancer or with a genetic susceptibility to developing this disease. It identifies six areas of concern: feeling unattractive due to treatment side-effects; perceiving limited dating partners available; cancer disclosure; fear of cancer recurrence; sexual intimacy anxiety; and, a sense of dating 'urgency'.Chapter 3 addresses significant gaps in the current literature and explores women's dating experiences after breast cancer. It identifies an overarching theme of 'navigating the breast cancer dating journey', comprising seven themes: the decision to consider dating; ability/desire to start a new relationship; cancer disclosure; changes to intimacy/sexuality; body image difficulties; changing values; and trusting a new partner.Chapter 4 examines factors associated with relationship formation difficulties (assessed via self-perceived interpersonal skills/competencies and dating-related anxiety) in breast cancer survivors. Results indicate that body image variables (self-evaluative salience and body image dissatisfaction) and attachment avoidance are associated with dating-related anxiety, whereas attachment avoidance and self-compassion are associated with self-perceived interpersonal competence scores.Chapter 5 details the development of a novel, online intervention to support women in romantic dating after breast cancer (Dating After The Experience-Breast Cancer; DATE-BC). Participants reported moderate-to-high acceptability, and recommended some improvements for future use and implementation.This thesis represents the first in-depth examination of romantic relationship formation after breast cancer, highlighting factors that should be targeted in survivor support interventions. Based on these findings, this thesis then presents a novel intervention to help women navigate the world of dating during cancer survivorship.Mode of access: World wide web1 online resource (xi, 248 pages) colour illustration
Game theory based dynamic spectrum sharing for next-generation mobile networks
No full textEmpirical thesis.Bibliography: pages 141-155.1. Introduction and motivation -- 2. Background and literature review -- 3. An equal-priority power-control game for spectrum sharing - 4. A multi-priority power-control game for spectrum sharing -- 5. A two-layer evolutionary game for LSA-based spectrum sharing -- 6. Cross border licensed shared access -- 7. Thesis conclusion ad future work -- List of acronyms --References.Next-generation mobile networks need to ensure flexible and effcient utilisation of the radio spectrum to keep pace with the rapid growth of mobile services and applications in recent years. This thesis presents novel game-theoretic frameworks for enabling dynamic spectrum sharing to achieve spectral effciency in next-generation mobile networks, and proposes novel ideas for dynamic allocation of spectrum resources among participating networks, while ensuring reliable quality of service (QoS) for all users through appropriate sharing rules, protocols and architectures. The spectrum-sharing schemes proposed in this thesis are categorised as power-control games for femtocell-based networks and games based on Licensed Shared Access (LSA).The main contributions of this thesis include formulating equal-priority and multi-priority non-cooperative power-control games for femtocell-based networks to achieve interference mitigation such that the QoS of the users served by the femtocells is not compromised. During the game, each femtocell, serving either the primary users or the secondary users of the spectrum, dynamically adjusts its transmit power until the transmit power is stabilised, adapting to its interferenc emeasurement and traffc. It is shown that the existence and uniqueness of the Nash equilibrium of the non-cooperative game can be achieved by carefully selecting the game parameters, which are designed to determine the priority status of the femtocells. Furthermore, the real-time signalling overhead is minimised between the networks through a novel dual-mode solution.Another key contribution of this thesis is the application of game-theoretic principles for dynamic spectrum sharing using LSA. A two-layer LSA-based evolutionary game is proposed which ensures demand-driven allocation of spectrum resources to LSA licensees. The scheme also incorporates dynamic price-adjustment strategies adopted by incumbents to ensure an improved total gain for the incumbents.The stability of the proposed evolutionary algorithm is proved using Lyapunov stability criteria. Furthermore, a practical scenario of LSA-based spectrum sharing is considered, and the LSA architecture is modified to enable mobile network operators acting as domestic licensees to provide an enhanced QoS in border areas, for minimising the effects of cross-border interference.Mode of access: World wide web1 online resource (xxiv 155 pages
Couples' communication in the breast cancer context
No full textTheoretical thesis.Bibliography: pages 91-108Chapter 1: Literature review -- Chapter 2: Empirical study 1 -- Chapter 3: Empirical Study 2 -- Chapter 4: General discussion -- 5. References -- 6. Appendices.Breast cancer is one of the most frequently diagnosed cancers among women in Australia. Whereas the past two decades have seen significant medical advancements and substantially improved diagnostic and intervention practices, the flipside of this progress is that an increasing number of women must contend with the myriad physical and psychological challenges of breast cancer and its treatment. Not surprisingly, a substantial proportion of women diagnosed with breast cancer experience elevated psychological distress in the form of anxiety, depression and post-traumatic stress many years after diagnosis and treatment. Explanatory research focused on interpersonal dynamics points to the importance of effective communication between spouses in facilitating psychological and relationship outcomes,such as,reduced psychological distress, and the maintenance or enhancement of couple relationship satisfaction. Few studies to date, however, have focused on couples' communication in cancer as a primary outcome, frequently using brief (typically single-item) and imprecise global indices of communication. Many questions, therefore,remain regarding how couples communicate about cancer, how they negotiate and co-ordinate coping, and the associations of specific dimensions of communication behaviours with psychological and relationship outcomes, and the underlying processes of these associations. Another limitation of the existing literature is that many of the studies have focused on positive dimensions of interpersonal and communication variables, such as social support dynamics and open disclosure of feelings, as compared to negative dimensions of interpersonal and communication behaviours. This is problematic as positive and negative social interactions are distinct constructs and relate to psychosocial adaptation outcomes in different ways, with some research even suggesting a more detrimental effect of negative social interaction, as compared to the beneficial effects of positive social interactions. An initial literature review was conducted to conceptualise the associations between major adaptive and non-adaptive communication strategies, and couples' psychological distress and marital satisfaction and to identify areas of knowledge gaps. Major theoretical and methodological frameworks that have guided this research, and directions for future research are the nconsidered.The two empirical studies in this thesis examine negative dimensions of couple communication behaviours and their linkages with key psychological and relationship outcomes in women with breast cancer and underlying processes of these associations. Specifically, the first empirical study examines the associations of patient-reported avoidance of specific cancer-related topics, reports of partner avoidance of these topics, and coping and psychological distress among breast cancer survivors. The results of this study indicated that greater women's and perceived-partner's communication avoidance about cancer topics were associated with poorer mental health outcomes (anxiety, depression, and stress) in the women with breast cancer. This study also provided support for the view that avoiding talk about cancer may influence the woman's emotional distress by impeding her coping ability, consistent with the transactional stress and coping paradigm. The second empirical study examines the association between perceived partner social constraints, as well as patient's report of their own social constraints, with patient relationship satisfaction.Previous research has only assessed perceived partner constraints, without consideration of the potential adverse effects of the patient's own constraints on partner disclosure and relationship satisfaction. The results of this study indicated that greater women's and perceived-partner social constraints were associated with poorer patient-reported relationship satisfaction. This study also provided support for the view that social constraint signals may be detrimental to relationship satisfaction by impeding individuals' social processing about cancer, consistent with the social cognitive processing model. Overall, the literature review and results of the two empirical studies contribute to the understanding of the role of couples' communication in breast cancer adaptation. The results of the two empirical studies indicate that the way in which couples communicate and relate with one another, the frequency of unsupportive responses, and topical focus of their conversations, are all important considerations for whether or not couple talk contributes to couples' psychosocial adaptation to cancer. The results hold important implications for clinical practice and care of women with breast cancer, as they suggest that helping couples navigate and overcome unsupportive partner constraint behaviours, and minimise communication avoidance about specific cancer-related topics between spouses may be important targets for psychosocial interventions.1 online resource (135 pages
Synthetic Cannabinoid activation of hTRPA1 and naturally occuring channel variants
No full textTheoretical thesis.Bibliography: pages 84-1051 Introduction -- 2 Materials and methods -- 3 Method validation -- 4 Effect of hTRPA1 polymorphisms on prototypic agonists -- 5 The effect of hTRPA1 polymorphisms on synthetic cannabinoids -- 6 Discussion.THC, the primary psychoactive compound in cannabis, is a low efficacy agonist of the CB1 receptor. Synthetic cannabinoids (SC's) are compounds structurally unrelated to THC, which also function as agonists of the CB receptors. Recreational SC products have been monitored since the emergence of JWH-018 in 2008, with new compounds rapidly developed to evade legislation and detection. SC consumption, including mass intoxication events, is associated with a range of adverse effects uncharacteristic of plant derived cannabinoids, such as psychomotor agitation, aggression, cardiac arrhythmias, seizures and death. The mechanisms of SC toxicity are not established, however, some SCs are higher efficacy agonists of CB receptors than common research cannabinoids, and have the potential to act at non-CB receptor targets. Polymorphic variants of these targets may influence individual toxicity. Transient receptor potential ankyrin 1 (TRPA1) is a calcium-permeable ion channel highly expressed in the brain, sensory neurons and the epithelium of the lungs. TRPA1 is activated by THC and some synthetic cannabinoids, with several naturally occurring polymorphic variants in humans. HEK293 cells stably transfected with human TRPA1 and five select SNP variants were studied by measuring changes in intracellular [Ca2+] in response to selected high concern SCs and some natural ligands. The SC's MDMB-CHMICA, PB-22, 5F-PB-22, UR-144, XLR-11 and 5-OH-UR-144 activate hTRPA1 and each mutant, although they exhibited varying degrees of efficacy between the mutants. The R58T variant resulted in increased activation by PB-22 and 5F-PB-22 compared to the WT. R3C, E179K, H1018R and R3C+R58T resulted in decreased activated compared to the WT by UR-144 and XLR-11. The 5-hydroxypentyl metabolite common to both remained unaffected by hTRPA1 polymorphisms, as did MDMB-CHMICA and two prototypic ligands, cinnamaldehyde and allyl isothiocyanate. At hTRPA1, XLR-11 was relatively more potent than the structurally similar UR-144. The common 5-OH metabolite exhibited greater relative potency than both parents at some hTRPA1 variants. THC was shown to be a more potent agonist at hTRPA1 than all synthetic cannabinoids tested. These data show that the efficacy of SCs varies at naturally occurring hTRPA1 polymorphisms, but that different drugs are affected in distinct ways. If SC toxicity is related to actions at non-CB proteins such as TRPA1, mechanisms of drug toxicity may be highly individualized.1 online resource (viii, 105 pages) illustration
Interconnectedness of electricity spot prices: A dynamic network analysis
No full textTheoretical thesis.Bibliography: pages 95-1021 Introduction -- 2 Literature Review -- 3 Background -- 4 Methodology -- 5 Data and Descriptive Analysis -- 6 Regression Analysis -- 7 ConclusionsThis present study constructs dynamic Granger causality networks based on the spot prices of five regional markets in the Australian National Electricity Market (NEM). Although transmission lines between adjacent states result in physical interconnection in the geographical sense, the degree of integration of wholesale electricity prices is still equivocal. Based on a data set comprising electricity spot prices from 1 July 2010 to 30 June 2017, this study employs principal component analysis and generates Granger causality networks to examine the degree of interconnectedness of the NEM in a time-varying setting. We find that the derived measures of interdependence can be related to actual market events such as price spikes; unexpected high demand for electricity; sudden increase in price volatility; rebidding of dominant generators; the temporary or permanent outage of major power stations; and upgrades and limitations in transmission capacity. The first measure is the cumulative risk fraction of the first few principal components, which conveys information on risk concentration. Another measure is the dynamic causality index generated from the estimated Granger causality network. In the analysed network, we find that stronger dependence is exhibited by regional markets that are linked by interconnectors, while the direction of the relationship can be related to inter-regional trade. Furthermore, this study examines the usefulness of the derived measures as early-warning indicators for upcoming periods of extreme prices and volatility. Our results suggest limited predictive power of the interconnectedness measures for spot price behaviour in the NEM.1 online resource (ii, 111 pages) illustration
Studying social influence on Twitter
No full textEmpirical thesis.Bibliography: pages 153-163.1. Introduction -- 2. Background -- 3. Principal features analysis for measuring user Influence -- 4. A hybrid feature selection method for predicting user influence -- 5. Influence maximization on Twitter : a mechanism for effective marketing campaign -- 6. Maximizing the effectiveness of advertising campaigns on Twitter -- 7. Conclusion -- References.The study of social influence has a long history in research areas of sociology and marketing. In recent years, with the rapid growth of Online Social Networks (OSNs), online influence has received lots of attention from both academic community and industry. For the work in this dissertation, we consider the Twitter platform and aim to address two problems: 1) feature selection for measuring social influence; and 2) influence maximization for marketing campaigns. While many researchers focus on measuring social influence on Twitter, there is still lacking of a comprehensive analysis of feature selection. Most existing studies directly utilize their own pre-defined features to build the model without evaluation and judgement for the seselected features. In order to find principal features for measuring user influence on Twitter, we select manifest features based on sociology knowledge. Besides principal manifest features, we identify hidden features and map them to the attributes of influencers in the research area of social science. Furthermore, we propose a hybrid feature selection method for predicting user influence. After evaluating the quality of features by utilizing a filter method, a reduced feature subset is obtained. Following the principles of wrapper methods, we assess the feature subset at each searching step. Finally, an optimal feature set with a high degree of accuracy for predicting user influence is obtained.Influence maximization is the most fundamental and important problem when studying social influence. In this work, we identify a specific influence maximization problem as selecting a set of seed users to maximize the effectiveness of advertising campaigns on Twitter. When studying influence maximization problem, we develop our solution with new ideas focusing on : 1) the definition of influence; 2)the influence probability model; 3) the influence diffusion model; and 4) the seed nodes selection algorithm. The proposed influence maximization approach has taken into consideration of social ties, user interactions, and the characteristics of advertising information propagation on Twitter. Our work provides a solid generic solution for promoting products or services in online social networks like Twitter.Mode of access: World wide web1 online resource (xviii, 163 pages) graphs, table
When Judaism lost the Temple: crisis and response in 4 Ezra and 2 Baruch
No full textTheoretical thesis.Bibliography: pages 223-235.1. Introduction: 4 Ezra and 2 Baruch in their historical, religious and literary contexts -- 2. Covenant in crisis in 4 Ezra -- 3. Eschatology and Torah in 4 Ezra -- 4. The unity and coherence of 4 Ezra and Its authorial intention -- 5. The structure and content of 2 Baruch in relation to Its authorial intention -- 6. The covenant in crisis in 2 Baruch -- 7. Eschatology and Torah in 2 Baruch -- 8. Baruch Ben Neriah -- 9. Conclusion : Conclusion: What Is in a name? Covenant tradition and apocalyptic revelation in 4 Ezra and 2 Baruch -- Bibliography.This thesis is a study of religious thought in two Jewish apocalypses, 4 Ezra and 2 Baruch, written around the end of the first century as a response to the destruction of Jerusalem and the Temple by the Romans in 70 CE. The true nature of the crisis is the perceived loss of covenantal relationship between God and Israel, and the Jewish identity that is under threat. Discussions of various aspects of thoughts, including those conventionally termed theodicy, particularism and universalism, anthropology and soteriology, are subordinated under and contextualized within the larger issue of how the ancient authors propose to mend the traditional Deuteronomic covenantal theology now under crisis.Both 4 Ezra and 2 Baruch advocate a two-pronged solution of Torah and eschatology at the centre of their scheme to restore that covenant relationship in the absence of the Temple. Both maintain the Mosaic tradition as the bulwark for Israel's future survival and revival; whereas 4 Ezra aims to implant its eschatology into the Sinaitic tradition and make it part of the Mosaic Law, 2 Baruch extends the Deuteronomic scheme of reward and retribution into an eschatological context, making the rewards of the end-time a solution to the cycle of sins and punishments of this age.Both texts are read as coherent works with a sophisticated literary structure, skillfully composed to convey authorial intentions. As such, the overall intended message can only be grasped after one has understood the development of the narrative structure. Considerable emphases are also placed on the significance of the portrayals of the pseudonymous protagonists, Ezra and Baruch, the use of symbolism in the two texts as scriptural exegesis, as well as their relationship with each other and links with the Hebrew Bible and other Jewish and Christian writings.Mode of access: World wide web1 online resource (xii, 235 pages
Portrayals of the Armenian genocide in Australian literature
No full textTheoretical thesis.Bibliography: pages 70-75.Exegesis. Portrayals of the Armenian genocide in Australian literature -- Creative section. A flicker of justice, no more -- Works cited.This thesis consists of a work of creative writing and an interconnected research component. Despite Australia's historical connections to the Armenian Genocide, there has been little research into portrayals of the genocide in Australian literature. This thesis analyses three such novels: Joan London's Gilgamesh, Marcella Polain's The Edge of the World, and Katerina Cosgrove's Bone Ash Sky.These novels demonstrate how popular portrayals of traumatic histories can work to keep the memory of such events 'alive' in society and, following Adorno, can act as a form of resistance against barbarity. These authors use narrative strategies such as psychic distance, narrative gaps, perpetrator motivations, and blurred perpetrator/victims roles to create a sense of alterity in order to confront complicity and do justice to the genocide's victims without alienating readers.The Australian contexts of the novels engage with the comparative dispossessions in both Australian and Turkish history to portray the challenge of remembering those dispossessed. The exegesis analyses how these three authors resist barbarity through their imaginative investments in the Armenian genocide's 'postmemory' and offer models for the working through of traumas such as genocide. In the creative work, a novella set in 1980s Sydney, the Armenian protagonist struggles to reconstruct the Armenian cultural narrative in a way that achieves a sense of justice.Mode of access: World wide web1 online resource (75 pages
The complexities of children's antisocial lie telling: a cross-sectional and longitudinal investigation
No full textTheoretical thesis."Centre for Emotional Health, Department of Psychology, Macquarie University" -- title page.Bibliography: pages 139-152.Chapter 1. General introduction -- Chapter 2. Contextual and age-related determinants of children's lie telling to conceal a transgression -- Chapter 3. Cross-sectional and longitudinal relationships between children's moral standards and their antisocial lie telling -- Chapter 4. The cross-sectional and longitudinal influence of specific parenting practices on children's antisocial lie telling -- Chapter 5. Longitudinal relations between lie telling and problem behaviors : a cross-lagged panel design-- Chapter 6. General discussion -- References -- Appendices.Despite being discouraged, children frequently tell lies to conceal their transgressions. Consequently, researchers have argued for the need to understand the complexities of children's lying. To advance this understanding, this thesis presents four laboratory-based studies, derived from one large-scale longitudinal study. The studies examine the cross-sectional (N = 443) and longitudinal (N = 298) influence of personal and environmental factors on lie telling across a broad age range of children (4- to 15-years) in both of the frequently used temptation resistance paradigm (TRP) tasks (guessing game, school-achievement task). Study one unconfounded age and task-type, finding support for the robust age-related decrease in lie telling after 8 years reported in previous research and demonstrating that the decrement in lie telling cannot be attributed to task-type. It also provided support for the situation-specificity viewpoint, showing that antisocial lie telling varies across tempting contexts. The results from studies two, three and four, further show that children's antisocial lying is differentially motivated depending on the tempting context. Study two showed that weaker internal moral standards led to more lie telling in the school achievement task concurrently and one year later. Study three showed that, depending on the time interval, harsh punishment was associated with more lie telling in the short-term, while lower levels of parental warmth led to more lie telling in the long-term. Finally, study 4 concurrently tested whether lie telling was the cause or effect of conduct problems using a cross-lagged panel design. Results indicated that lie telling is a problem behavior at the outset, rather than developmentally normative, as it follows engagement in conduct problems. Collectively, these studies show that personal and environmental factors play a complementary role in children's lying. They also provide the first causal longitudinal evidence of the relationships among personal and environmental factors related to children's lie telling.Mode of access: World wide web1 online resource (x, 170 pages) diagrams, table