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Predator-Prey Interactions Between Paranephrops zealandicus and Odonata Species in Semi-natural Aquaculture Environments
No full textInteractions between predator and prey contribute towards shaping food webs and can be responsible for the composition of species in an ecosystem. In semi-natural aquaculture ponds, interactions between predators and competitors can be unfavorable for farmed species as they might reduce biomass in ponds and therefore economic growth. Juvenile farmed species are significantly more vulnerable in pond aquaculture as size is usually the factor that dictates trophic levels in aquatic habitats. Odonata are a family of pond invertebrates that are considered opportunistic predators and are known to feed on the prey of many juvenile vertebrate and invertebrate ponds species. Their ability to successfully capture prey makes them top invertebrate predators and how they interact with farmed species, specifically juveniles in aquaculture pond systems has been speculated. In New Zealand (NZ), semi- natural aquaculture ponds are used to cultivate the freshwater water crayfish species Paranephrops zealandicus yet how this species interacts with other pond invertebrates, particularly odonate larvae has not been studied. It was therefore the aim of this thesis to further investigate the predator-prey interactions between NZ odonate larvae and the farmed species P. zealandicus in semi-natural aquaculture ponds. This thesis examines predator-prey interactions based on species spatial patterns and habitat use in ponds, as well as stomach content and stable isotope analysis on study species.
Results indicate odonate larvae have no significant effect on the abundance of P. zealandicus in ponds. Vegetation and the densities of P. zealandicus in ponds are more likely to have a greater impact on odonate larvae and juvenile P. zealandicus abundance. Desirable habitat was occupied by larger P. zealandicus which forced juvenile P. zealandicus to seek refuge in areas of the pond that were not attractive for larger territorial individuals. Based on stomach content analysis, odonate larvae were found to primarily feed on small sedentary pond invertebrates such as Chironomidae P. zealandicus tissue was exceptionally low in odonate larvae stomachs. Stable isotope analysis further showed all odonate larvae had lower trophic levels to juvenile P. zealandicus indicating odonate larvae are unlikely to be major predators of juveniles. P. zealandicus diets reflected their omnivorous nature feeding on both plant detritus and invertebrate tissue, however P. zealandicus were highly cannibalistic with adults found to have high volumes of P. zealandicus tissue in their stomachs. Stable isotope analysis showed between P. zealandicus and juvenile crayfish there was no significant difference in trophic levels. Year 1 crayfish represented much of the P. zealandicus sample used for stable isotope analysis and adults were poorly represented in the sample which could be the reason for this result. Therefore Year 1 P. zealandicus are unlikely to be feeding on juveniles, however more research needs to be carried out looking at the trophic interactions between adult P. zealandicus and year of young.
Ultimately, odonate larvae are not likely to be major predators of juvenile P. zealandicus, and cannibalism is more likely to be the main factor for low juvenile success in ponds. Future research investigating other pond invertebrates and ways to mitigate cannibalism in ponds is speculate
Systems-practice framework: An integrated approach for foodservice management
No full textThere is increasing pressure on foodservice organisations to improve the sustainability of their operations and to do so practitioners must be equipped with appropriate tools. In this paper, a tool to guide management strategies for pro-environmental behaviour change is introduced. The tool is based on a new framework that combines two existing models: the widely used foodservice ‘systems model’ and a model from sociology proven to be effective for understanding sustainable practices, the ‘social practice model’. This new hybrid ‘systems-practice’ framework is applied to an ethnographic case study, using document analyses, observations, focus groups and interviews, to investigate food waste in hospital kitchens. The present case study illustrates the practical implications of employing this approach and enhances the external validity of the proposed framework. The present study showed how the social practice model added to the existing systems model emphasised the role of foodservice personnel for generating pro-environmental practices, and thus offered a more people-based approach to foodservice management. The case study data provided evidence for the efficacy of a systems-practice approach to foodser-vice. This is especially relevant for encouraging a more environmentally aware behavioural orientation within food service systems. Based on easy-to-follow steps presented in the adjoined ‘application of the systems-practice guide’, practitioners can use the framework to either understand practices that already exist in their operations, with the purpose being to ensure further systemisation of positive practices, or to effect change by creating new sustainable practices and phasing out existing unsustainable practices
RNA sequencing of non-coding RNAs in ischaemic heart disease
No full textIschaemic heart disease is a major cause of death worldwide and a leading cause of mortality and morbidity in New Zealand. Older adults and those of Māori and Pacific ancestry are particularly affected. Ischaemic heart disease accounts for over half of all cardiovascular disease mortality and, again, rates are more than twice as high among Māori than non-Māori. Ischaemic heart disease can lead to myocardial infarction (heart attack) which, if not fatal, can then lead to heart failure, a complex, multifactorial disease characterised by neurohormonal signalling and remodelling of the heart. Currently the natriuretic peptides are the international gold standard for diganosing heart failure and are also excellent prognostic markers in patients with heart failure. However, there is still a clinical need for early biomarkers of myocardial ischaemia (to identify people at risk of myocardial infarction) and to identify patients at risk of developing heart failure before detrimental remodelling has occurred.
As sequencing technologies have evolved there has been intense research in the fields of circulating cell free DNA and RNA, especially non-coding RNA. As RNA is actively transcribed, it has the advantage of providing a ‘real time’ insight into the disease status of an individual. Recent discoveries have highlighted the regulatory roles and diseases associated with non-coding RNAs, including long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs). LncRNAs have been demonstrated to have mutliple functional roles both within the nucleus and cytoplasm such as chromatin remodelling, histone modification, transcription factor recruitment, formation of subnuclear structures and control of mRNA translation and decay. CircRNA, a relative newcomer, has also been demonstrated to have functional roles such as sequestering miRNAs, binding proteins and even coding for peptides. There is great excitment for the potential utility of circRNAs as biomarkers as, due to their circular structure, they are more resistant to degradation in the circulation than their linear RNA counterparts.
The overall aim of this thesis was to identify non-coding RNAs associated with ischaemic heart disease. To address this aim, a bioinformatics pipeline was developed to identify mRNAs, lncRNAs including putative novel lncRNAs, and circRNAs using short-read RNA Sequencing (RNA-Seq) data. This pipeline was tested and validated with publicly available data and used to screen for candidate mRNA and lncRNA biomarkers associated with ischaemic heart disease in human heart tissue. A whole genome network correlation approach identified several promising candidate biomarkers for myocardial ischaemia including several novel lncRNAs, which were validated with long-read Nanopore sequencing in independent samples. The sub-cellular localisation of three promising lncRNAs candidates (two annotated lncRNAs, one novel lncRNA) was identified using the in-situ hybridisation assay, RNAscope®. Next, an RNA-Seq protocol was developed to detect mRNAs, lncRNAs and circRNAs in human plasma. This protocol was applied to plasma from patients with ischaemic heart disease and healthy controls to screen for candidate mRNA, lncRNA and circRNA biomarkers for progression from ischaemic heart disease to heart failure. Although candidate biomarkers for disease progression could not be detected in these patients several additional lncRNA candidates for the presence of ischaemic heart disease were identified.
In summary, this study has established a bioinformatics pipeline and methodology for identifying and validating putative novel lncRNAs and circRNAs in human tissue and plasma. This work has identified several promising candidate lncRNA biomarkers for ischaemic heart disease, which, if validated, may provide early diagnostic information in high-risk patients.
The pipeline is freely available to download at https://github.com/zoeward-nz/Ph
Low-input transcriptomics of developing pollen in Arabidopsis thaliana
No full textPollen is the male gametophyte of flowering plants that deliver sperm cells to the female gametophyte during fertilization. Pollen development begins with the reduction division (meiosis) of a single pollen mother cell to produce four microspores in a process called microsporogenesis. The microspores undergo two rounds of mitotic divisions to eventually produce a mature three-celled pollen composed of a large vegetative cell and two small sperm cells. A key challenge in plant reproductive biology is to understand the molecular and genetic mechanisms regulating these complex processes. Efforts to analyse the gene expression during pollen development by generating its transcriptome has been limited due to challenges associated with generating a pure and homogeneous developing pollen sample.
To facilitate gene expression and transcriptomic analysis of developing pollen, I have developed a novel Low-input Developing Pollen (LiDP) method that allows isolation of pure and homogeneous Arabidopsis thaliana (Arabidopsis) pollen samples belonging to a narrow developmental window. The LiDP method involves the separation of up to three anthers from a bud that is nicked to release their pollen. The pollen is washed to remove non-pollen transcripts and frozen for future use whereas the nicked anther together with remaining pollen is stored in a fixative. The fixed pollen is later staged by DAPI-staining and microscopic analysis to determine its developmental stage. Appropriate pollen samples stored in the freezer are then selected based on their stages and eventually lysed using a chemical called MMNO. Finally, the lysed pollen extract is directly used for RT-qPCR, digital droplet PCR or RNA sequencing (RNA-Seq). The ‘pollen lysis condition’ had minimal effect on RNA quality but showed partial degradation of mRNA 5`-ends. The lysis condition showed negligible effect on RT-qPCR amplification efficiency but reduced the mapping quality of RNA-Seq reads evidenced by increasing number of reads mapping to intergenic regions and reads that mapped to more than one position on the genome.
The LiDP method was used to generate the first RNA-Seq-based transcriptome of developing pollen from four discreet stages- uninucleate microspore (UNM), polarised microspore (PUNM), late bicellular pollen (BCP) and late tricellular pollen (TCP) stages. Analysis of the RNA-Seq data revealed global gene expression patterns that coincided with the molecular classification of pollen development into early and late developmental phases. Differential expression analysis revealed novel pollen-expressed genes that may play critical roles in pollen development and can now be tested in planta. Several pollen-specific genes were identified for the future development of cell-type-specific markers. Overall, the LiDP transcriptome offers a roadmap for further investigation of gene regulation in developing pollen , especially from the PUNM stage that was never studied before.
Finally, to assess the LiDP method’s usefulness the method was utilized to address a duo4 pollen development mutant and to test the hypothesis that the misexpression of DUO4 may lead to failed germ cell division in duo4 pollen through early degradation of mitotic CYCB1;1 (CYCLINB1;1). Investigation of DUO4 expression using LiDP RT-qPCR revealed considerable DUO4 expression at BCP stages of +/duo4 pollen but not in WT which supports the hypothesis that DUO4 is misexpressed at BCP in +/duo4 pollen. However, targeted amplicon sequencing of WT and duo4 transcripts in +/duo4 plants close to PM I and PM II revealed the typical 1:1 ratio between the two transcripts. These results demonstrated the utility of the LiDP method to address gene expression in specific stages of pollen development mutant
A Critique of Martyn’s Commentary on Galatians with an Emphasis on the Kingdom of God
No full textA Critique of Martyn’s Commentary on Galatians with an Emphasis on the Kingdom of Go
The Passionate Puritan
No full textSet in 1912, The Passionate Puritan follows young teacher Sidney Carey to an isolated kauri-milling community in the far north. She discovers romance there, but will she be able to seize it, or will puritanical conventions spoil her life? Social progress and conservatism battle for supremacy in the vivid setting off the Puhipuhi in the days of the old timber industry
A Tale of New Zealand
No full textOrphaned and alone, the young governess Annie Barrington sail to New Zealand in search of her lost brother. In Auckland, she finds instead a man who offers her happiness, but whose past hides a dark crime. Also, trying to escape the past are Annie's employer, Mrs. Willoughby Watkins, and her stylish friend Mrs. De Costremonge, who discover that conquering colonial high society is not as easy as they hoped. Back in England, Annie's friend Laura Scott waits in vain for news of her absconded husband. When Laura receives a fatal letter from the other side of the world, it threatens to destroy all that Annie holds dear
Constructive Arrows: An Introduction to Categories, Toposes and Logic
No full textCategory theory, especially topos theory, admits a new perspective on the study of logic and mathematical foundations. In this dissertation, we provide an introduction to the development of logic in a topos, and show why this logic does not validate the law of excluded middle. Assuming no prior knowledge of category theory, we motivate and introduce some main concepts of categories that allow for defining a topos. We briefly provide an introduction to order theory, giving the tools needed for analysis of the subobject algebras in a topos. We introduce the domain of formal logic and define propositional logical valuations on the subobject algebras and on a topos. We end with showing how the topos logic is intuitionistic, by virtue of the subobject algebras being Heyting algebras
Some microbiological aspects of the short eared European hedgehog, erinaceus europaeus, in New Zealand
No full textAmong English farmers and game wardens, a large body of folklore on hedgehogs has existed for centuries. The first scientific description of these mammals was contained in Barrett-Hamilton’s ‘A History of the British Mammals’ published in 1910. Herter’s ‘Der Biologie der Europaeischen Igel’ written in 1938 includes a wider summary of continental literature which is based largely on the study of laboratory or tame animals.
Despite the return of interest to mammalian field studies over the last decade or so, it is somehow surprising that such a common animal as the hedgehog has been generally overlooked. In New Zealand, Wodzicki (1950) and Brockie (1958) have both examined aspects of the ecology of the hedgehog, Brockie intimating that the hedgehog population of New Zealand far exceeds that of Britain. The contact between man and hedgehogs participating in some of the zoonoses in this country cannot be overlooked.
This thesis is an attempt to determine what part New Zealand hedgehogs play in the spread and carriage of human and animal diseases. The work is divided into three sections: Section I dealing with dermatophytes and yeast recoverable from hedgehogs; section II with bacteria; and section III with a discussion on some ecological aspect of the skin microflora. [from Introduction
Constitutive surveillance and social media
No full textStarting from the premise that surveillance is the ‘dominant organising practice’ of our time (Lyon et al 2012: 1), this thesis establishes a framework of ‘constitutive surveillance’ in relation to social media, taking Facebook as its key example. Constitutive surveillance is made up of four forms: economic, political, lateral, and oppositional surveillance. These four surveillance forms – and the actors who undertake them – intersect, compound, and confront one another in the co-production of social media spaces. The framework of constitutive surveillance is structured around a Foucauldian understanding of power, and the thesis shows how each surveillance form articulates strategies of power for organising, administering, and subjectifying populations. After outlining the four surveillance forms, each chapter unpacks the relationship of one form to social media, building throughout the thesis an extensive critical framework of constitutive surveillance