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The risks of trading on cryptocurrencies: A regime-switching approach based on volatility jumps and co-jumping behaviours
Get PDFPrevious research has shown volatility jumps and co-jumping behaviours in cryptocurrency markets. Motivated by these findings, we employ the herding effect and financial contagion channel to outline a theoretical framework of volatility-state-dependent correlations in cryptocurrency markets. We show that digital currency markets are more strongly correlated when experiencing an identical volatility regime, which echoes co-jumping behaviours addressed by the literature. Moreover, the strong correlation that occurs when the paired cryptocurrencies simultaneously experience a high volatility regime results in the least effectiveness of diversification in terms of a minimum portfolio risk reduction. Last but not least, the proposed state-dependent approach in this study proves effective at the task of risk forecasting and risk reduction for cryptocurrency portfolios, beyond the bivariate GARCH-based models, which are a pure and simple time-dependent approach
Principals’ partnerships: an action research study on the professional development of New Zealand school leaders
Get PDFThis report describes an action research study conducted between 1992 and 1995 with 12 New Zealand primary school principals.
Prior to this study, major administrative changes in the education system in New Zealand had been introduced, to give schools more responsibility for their own management in conjunction with elected committees of parents. This research sought a model of professional development which would assist principals to implement new ideas and practices, deal effectively with the current issues and problems in their schools and provide skills, challenges and support.
This was a qualitative study in which an action researching community, consisting of the principals and an academic researcher, met regularly using peer partnerships and group meetings to provide observation, reflection and evaluative feedback on leadership practice.
The questions that guided the research study were:
1. Do partnerships assist in the professional development of primary school principals?
2. If so, in what ways?
This research was designed as a conscious effort to not only develop a theory of professional development for school leaders but in so doing, to provide professional development which would help the school leaders to understand and then change their situation. The underlying theoretical principle of praxis was embedded and interwoven throughout the researcher’s and principals’ actions. The research was practical and based on the needs and concerns of the principals involved. In this way it was both a research and development model.
The findings were analysed using grounded theory techniques within a structure of action research. Thus, the processes of action research in this research study became a method for the analysis process as well as for that of data collection. The community of researchers were jointly involved in the analysis of the findings in this research. There were 18 months of data gathering using methods of oral and written reflections, interactive interviewing, observations and examination of records.
The 12 primary school principals in this study testified that the partnerships’ programme assisted in their professional development. In the words of one principal:
This research has made me focus on my own educational leadership. It has led me through a series of processes which has enabled me to reflect on and analyse my own actions. The research has made me take an in-depth look at my own leadership style and has given me the opportunity to observe others.
The ways in which these principals believed they had gained from their involvement in the research fell into four major categories. The Partnerships’ programme assisted critical reflection on practice to occur; it increased professional interactions; it assisted in educational leadership development and finally, it established a structure for the principals to use processes of action research for school development. The vehicles for the principals to achieve praxis were reflection and alternative perspectives. Praxis led to emancipatory actions and feelings of agency. The principals’ partnerships, the involvement of the university researcher and the meetings of the community of action researchers, became integral parts of this process.
The thesis that is presented rests on the principals’ perceptions that a model of professional development which involves principals in partnership, with the support and challenge from a university academic, can successfully provide the essential components of professional development programmes in which praxis is the desired outcome.
This thesis concludes that the Partnerships’ programme assisted in the professional development of these 12 school leaders. The principals, when working together in each other’s schools, created a mild disruption to everyday practice which led to opportunities for reflection on leadership practices. The university researcher also assisted in this intervention process. The combination of the two was effective to enable critical reflection on practice and subsequent change in practice to occur.
On the basis of these findings a grounded theory of professional development is offered and recommendations are made for further research in this area
Climate strike experiences: Youth voice informing secondary schooling in Aotearoa New Zealand
Get PDFYouth voices led the climate strikes of 2019 and motivated millions to take to the street and demand climate action. Aotearoa New Zealand is experiencing more frequent and devastating weather events such as flooding, cyclones, droughts and fires, evidence of the Intergovernmental Panel on Climate Change’s assertion that if greenhouse gas emissions continue to go unchecked, the impacts on humans and ecosystems will be irreversible, pervasive, and severe. Furthermore, those least responsible for the causes of climate change are likely to be the most affected. This includes the youth of today.
Despite the predicted scale of the impact climate change might have on future generations, academic literature relating to youth concerns and perceptions on climate change education has also been limited. While this research largely confirms what is already known about climate change education in secondary schools, it has focused on youth perspectives, and this is where the value lies by offering a theoretical contribution to pedagogical practise based on the voices of youth climate strike leaders. Education traditionally mirrors the cultural norms of society and secondary schools have not shown a willingness to engage with their youth about climate change education.
This thesis is grounded in a Freirean theoretical position, the context of which, supports an education process that enables students to become agents of change and argues for greater implementation of holistic critical pedagogies in secondary schools. The 2019 climate strikes represented an uprising of youth, through this action the strike leaders’ experiences led to their realisation that climate instability necessitates an educational shift away from prioritising cultural reproduction to an education system that supports cultural transformation. With a critical theory lens, I explore the barriers and opportunities within secondary schools in regard to climate change education and ask what teachers can learn from the climate strikes experience.
The purpose of this research was to consider youth voice and question what educators can learn from the climate strikes by exploring the experiences of climate strike leaders in Aotearoa New Zealand. Understanding the motivational factors behind youth climate action and gaining pedagogical insights into effective climate change education is critical to future curriculum content and classroom practices. Using an interpretivist paradigm with a critical theory lens, rich qualitative data were collected. In-depth, semi-structured interviews with 15 geographically and culturally diverse climate strike leaders and eight secondary school teachers were conducted via zoom. Interview data were triangulated by document analysis of online media articles relating to the climate strikes. Thematic analysis identified key emerging messages.
The key findings identified in this research pertained to why and how questions. The why consisted of motivational factors that engaged youth to take climate action which included the soaring levels of climate anxiety among youth and how eco-anxiety is pivotal for demotivating or motivating climate action. With consideration of Boler’s (1999) conceptual framework, the Pedagogy of Discomfort, I propose a progressive model of emotional responses that frame the strike leaders’ emotional journey from apathy through anxiety to action. The conceptual framework aims to be transformational by inviting individuals to explore the root causes behind their anxiety and develop active strategies that encourage participants to reflect and identify, their perceptions and society’s expectations.
The how considered the value of youth voice for increasing engagement; how enhanced understanding of social justice and indigenous rights is more likely to engage youth towards political agency than learning about ecological collapse; and how enhanced political agency empowers youth to feel they can make a difference, which also reduced their anxiety. Importantly, embracing Orr’s (1992) critical pedagogical practice that balances academic (head), emotional, (heart), and practical (hands) learning is more likely to foster critical thought that engages a wider audience with climate change education that leads to climate action.
The strike leaders concluded that formal secondary school education plays an essential role for their future but is yet to fully realise the transformative potential it has. Youth are demanding climate action and argue that educators have a responsibility to support and contribute to bringing about the changes needed for the ecological and societal challenges youth face in a climate altered future
Contribution of soil bacteria to the atmosphere across biomes
Get PDFThe dispersion of microorganisms through the atmosphere is a continual and essential process that underpins biogeography and ecosystem development and function. Despite the ubiquity of atmospheric microorganisms globally, specific knowledge of the determinants of atmospheric microbial diversity at any given location remains unresolved. Here we describe bacterial diversity in the atmospheric boundary layer and underlying soil at twelve globally distributed locations encompassing all major biomes, and characterise the contribution of local and distant soils to the observed atmospheric community. Across biomes the diversity of bacteria in the atmosphere was negatively correlated with mean annual precipitation but positively correlated to mean annual temperature. We identified distinct non-randomly assembled atmosphere and soil communities from each location, and some broad trends persisted across biomes including the enrichment of desiccation and UV tolerant taxa in the atmospheric community. Source tracking revealed that local soils were more influential than distant soil sources in determining observed diversity in the atmosphere, with more emissive semi-arid and arid biomes contributing most to signatures from distant soil. Our findings highlight complexities in the atmospheric microbiota that are relevant to understanding regional and global ecosystem connectivity
Ecology of aquatic hyphomycetes in New Zealand streams
No full textThis work investigated the occurrence of aquatic hyphomycetes in stream ecosystems in New Zealand. It provided evidence for the potential importance of detrital cycles in such ecosystems and of the role of aquatic hyphomycetes in the decay of leaf litter. Leaves from a representative range of plant species were enclosed in mesh bags in two undisturbed streams flowing through different forest types at different altitudes, and fungal population dynamics followed during leaf decay. A method was developed, using pure cultures of appropriate aquatic hyphomycetes, which enabled the mycelial content of leaf material (m mycelium/g) attributable to individual fungal species to be quickly and easily determined from the spore production measured from leaf samples. Antibiotics were used to quantify the relative fungal and bacterial contributions to microbial activity of leaf samples through the selective inhibition of respiration. Fungi accounted for about half of the total microbial respiration, and on average 80 % of this fungal respiration was attributable to aquatic hyphomycetes.
Three major patterns were apparent from the data for aquatic hyphomycete population dynamics. 1) A successional pattern was identified among aquatic hyphomycetes, with the species falling into three groups on the basis of the order of their period of abundance. 2) Aquatic hyphomycete abundance varied among leaf types, with soft-rotting types (hangehange, young kanono) being poorly colonised compared to firmer, darker-rotting types (old kanono, kamahi, silver beech, tawa, kauri, and rimu). Nikau (palm) and ponga (fern) leaves, although not soft-rotting, were also poorly colonised by aquatic hyphomycetes, but bore a rich alternative mycoflora. 3) The occurrence of many aquatic hyphomycetes showed seasonal preferences and a distinct geographical distribution which followed that of higher plants. Both seasonal and geographical patterns were probably related to temperature.
Laboratory evidence was obtained of the potential importance of oxygen in determining aquatic hyphomycete occurrence, with the dominant species in most New Zealand streams (Lunulospora cymbiformis) being extremely intolerant of low oxygen conditions. Two new species of aquatic hyphomycetes were isolated in the course of the work
Mill wives: a study of gender relations, family and work in a single-industry town
Get PDFThe experiences and everyday practices of wives of production workers in a town with one dominant industry that imposes a variety of demands on workers and their spouses is the focus of this thesis. The town is Kawerau, established for the milling and manufacture of timber, pulp and paper, and situated in the Bay of Plenty, New Zealand. It has a specifically masculine character on account of restricted employment opportunities and traditionally male occupations.
I am concerned with the ways in which the women are engaged in maintaining home and family. Marriage constitutes the ground for establishing a household, and the complementary relationship between spouses is central to creating a home. This complementarity is expressed through male employment, for many involving shiftwork, and the primary involvement of women with domesticity. Those women who were also employed modified their involvement according to domestic and family obligations, which were given prior importance. Though both may be wage earners, wives and husbands have different obligations and orientations to the family.
Complementarity is made visible through gender distinctions; a major one being the wife and ‘home’s’ reliance on the husband’s job. His job provides the necessary financial basis for the home. Its contractual and disciplined character pervades the home and furnishes the conditions under which the women as wives are expected to cope domestically. A wife’s access to housing and income sufficient to maintain personally acceptable standards are influenced by the husband’s contract with the mill.
Creating a home and maintaining family life are continual processes, achieved through managing the consequences of the husband’s job by the wife, in the confines of their home. This thesis highlights three aspects of his job which, as ‘givens’, constrain the woman’s organisation of the household in significant ways: the husband’s wage, hours of work (especially shiftwork) and industrial disputes. It is the contradictions and ambivalence involved in coping with these aspects that I explore. The study is influenced by feminist theoretical work concerning the relationship between ‘home’ and ‘work’ and ‘public’ and ‘private’ as symbols and experience
Anti-irrationalism in Izydora Dąmbska (1904-1983)
Get PDFA summary of Polish philosopher Izydora Dąmbska's views on logistic anti-irrationalism
Development and characterisation of low-cost powder metallurgy Ti–Cu–Fe alloys
Get PDFThe high cost of Ti alloys is still a primary hindering factor for their wider adoption in different engineering sectors in which they would bring significant benefits. This study analysed the simultaneous addition of cheap alloying elements (i.e. Cu and Fe) aiming to quantify the properties of new low-cost ternary TieCueFe alloys obtained via powder metallurgy. It is found that, the amount of alloying elements decreases the compressibility of the powder blends but similar relative density values to those of other powder metallurgy Ti alloys can be achieved. The addition of Cu and Fe leads to the creation of alloys with a lamellar microstructure whose features such as prior b grain size, morphology, interlamellar spacing, and formation of a eutectoid substructure, are determined by the specific chemistry of the alloy. Consequently, the deformation and failure of the sintered ternary TiexCuexFe alloys is governed by the same mechanism but the strength, hard-ness, ductility, and strain hardening rate are alloy dependent
Spatial and temporal characteristics of the underwater soundscape around the Motiti Protection Area: Ōtaiti/Astrolabe Reef and Motiti Island
Get PDFMarine ecosystems around the world have been impacted by degradation and loss of biodiversity as a result of human impacts and climate change. The monitoring and management of ecologically significant areas is vital in understanding the effects of habitat degradation on marine ecosystems. Traditional monitoring methods are often expensive, time consuming, labour intensive and invasive. Soundscapes offer a unique opportunity for monitoring habitats in a way that is cost effective, minimally invasive and efficient. The aim of this study was to use passive acoustic monitoring to create a baseline data set using ambient sound data to investigate the spatial and temporal changes in ambient sound pressure levels, and to identify biotic, abiotic and anthropogenic sound sources which make up the marine soundscapes at the Motiti Island and Ōtaiti/Astrolabe Reef. Five diverse and ecologically significant sites in the Motiti Protection Area – at Ōtaiti/Astrolabe Reef and Motiti Island, in the Bay of Plenty, New Zealand were selected and monitored over the course of a year. This provided a wide variety of data to show the diel, lunar and seasonal patterns and trends in acoustic biological activity in order to represent the ecosystems accurately. The results showed that all sites showed strong diel patterns, with a sound pressure level increase of ~6-10dB during daylight hours compared to dark hours, and evident peaks during dawn and dusk hours as a result of biological choruses composed largely of sea urchins. There were also strong seasonal trends among the five sites, with Summer having the overall highest sound pressure level compared to Spring, Autumn and Winter, this also had an effect on the peaks in dusk choruses, which were also found to be highest during Summer. Lunar phases were also found to have an impact on the sound pressure levels of all five sites, with increased sound pressure levels during the new moon, compared to sound pressure levels during the full moon. This study created a baseline data set for a culturally, ecologically, and economically valuable area. Passive acoustic monitoring was found to be an incredibly useful tool in understand the ecosystems health and biological condition, and offers an alternative to traditional monitoring which is an effective, minimally invasive, and less labour intensive way of monitoring marine ecosystems
Characterisation of the aroma profiles of New Zealand monofloral honeys
Get PDFNew Zealand hosts a variety of monofloral honeys with distinct aromas and flavours. These sensory properties are determined by the volatile organic compounds present in the honey, of which over 600 have been identified. The volatile profile of honey is primarily influenced by botanical origin, geographic origin, storage and processing conditions. Not all compounds in the volatile fraction are represented in the aroma profile of the honey, due to the varying odour thresholds at which compounds can be detected by the consumer. Volatile compounds in New Zealand honeys have previously been studied for authentication purposes, but no New Zealand studies to date have linked the volatile composition with honey aroma. Thus, the aim of this research was to develop and optimise a method for the extraction and analysis of volatile compounds in New Zealand monofloral honeys, to determine the chemical differences responsible for the unique aromas of honeys of different botanical origins.
Various methods were trialled for the extraction of the volatiles, which are present in very low concentrations, from the complex honey matrix. Solvent extraction using dichloromethane was chosen, and samples were analysed by gas chromatography-mass spectrometry in selected ion monitoring mode. This demonstrated excellent sensitivity at the low part-per-billion level and allowed for identification of compounds not seen in total ion chromatograms. The method showed excellent precision and linearity over wide concentration ranges. Eighteen compounds were semi-quantified using this method, with full quantification achieved for four of these: nonanal, cineole, benzyl alcohol and guaiacol. Additional volatiles were screened using total ion chromatogram.
The optimised method was used for the analysis of 44 New Zealand monofloral honey samples spanning 11 floral origins. All 18 compounds were detected in all honey types, but not in all samples. ᴅ limonene, β-ionone and cineole are reported for the first time in any New Zealand honey, and phenylacetaldehyde and nonanal are reported for the first time in kānuka (Kunzea ericoides) honey. Results were comparable with the literature for these honey types, with mānuka honey characterised by o-methoxyacetophenone and kāmahi honey by 4-oxoisophorone. New Zealand clover honey contained low levels of volatiles which has also been reported for international clover honeys. The volatile profiles were also compared with odour thresholds to suggest possible aroma contributors for each honey type. Nonanal was determined to be aroma-active in all honeys analysed, and cineole in all but ling, lotus/blackberry and rātā. Chemometric methods including principal component analysis, classification and regression trees and linear discriminant analysis were used to identify similarities in samples based on their volatile profiles. Samples were classified by honey type using linear discriminant analysis with 82.9% accuracy, with the most accurate classification achieved for kāmahi and kānuka honeys