The Ecology and Palaeoecology of Diatom – Duckweed Relationships

This thesis focuses on the ecology and palaeoecology of diatom-duckweed relationships and utilises a combined experimental, ecological and palaeoecological approach. In particular, the study sought to determine the potential of the epiphytic diatom Lemnicola hungarica to be utilised as a proxy indicator of past dominance of duckweed (Lemna) in small ponds. To this end, contemporary sampling of epiphytic diatom assemblages from a variety of macrophytes (including multiple samples of free-floating plants) were collected from around the world and analysed for diatom epiphytes. In this study, even despite significant environmental gradients, L. hungarica showed a significant association with free-floating plants (including Lemna spp.) as did Sellaphora seminulum. To determine whether this relationship might be used to infer Lemna-dominance in sediment cores, diatom assemblages were analysed in surface sediments from English Lemna and non-Lemna covered ponds and in a core from a pond (Bodham Rail Pit, eastern England) known to have exhibited periods of Lemna-dominance in the past. In both cases, the data suggested that both L. hungarica and S. seminulum were excellent predictors of past Lemna-dominance. Finally, to infer the consequences of Lemna-dominance for the long-term biological structure and ecosystem function of the Bodham Rail Pit, the sedimentary remains of diatoms, plant pigments, and plant and animal macrofossils were enumerated from two sediment cores. These stratigraphic data were compared with the diatom Lemna-indicator metric which indicated three distinct Lemna cycles. Sediment core analyses suggested major compositional, structural and ecological changes brought about by the Lemna cycles, especially in the submerged macrophyte community and in fish-invertebrate relationships. These data reveal that duckweed proliferation, often brought about by eutrophication and terrestrialisation in ponds, can result in dramatic ecological changes due to a strong physical ecosystem engineering effect

An analysis of the level of participation in sport by learners with disabilities in inclusive settings

A journal article on sports participation of disabled students in the education sector of Zimbabwe.The practice of physical activity goes beyond providing access to programmes and making accommodations to support participation. It embraces the principle of non- discrimination of persons with disabilities and promotion of equity. In this paper, the authors attempt to discuss the extent to which learners with disabilities participate in sport within inclusive settings. Questionnaires and interviews were administered to the teacher and pupil samples, hence, a quantitative and qualitative approach was adopted for the study. Results revealed that children with disabilities were being sidelined with regards to participation in sport. It also emerged that specially trained personnel and material resources were not available to enhance the objective of inclusive physical activity. The need for in-house training for regular school teachers is vital. Sporting environments and equipment should be adapted to facilitate participation of children with disabilities in inclusive sporting activities

Exploring metaphor use and its insight into sense making with executive coaching clients

The difficulty coaches face in relating to and understanding how clients perceive and interpret situations is that the process for clients making sense of situations is unconscious. This presents a challenge, as there isn’t a direct or obvious route to access a client’s unconscious. Understanding clients’ use of metaphor offers a potential route to access this unconscious process and gain insight into clients’ sense making. The research adopted a critical realism paradigm and used a thematic analysis methodology with semi-structured interviews of eight executive leaders. The findings suggest that metaphor can offer insight into participants’ character and values, and coaches and leaders can use an approach of working with metaphor as a potential route to reveal and understand individuals’ unconscious sense making

Tertiary students’ perceived value of practical work as contributing to the learning of science

This thesis focuses on practical work as pedagogy in the teaching and learning of science. In particular the emphasis is on students’ perceived value of practical work in science courses offered from pre-degree to final year degree level courses at a university in Auckland, New Zealand. It seems a common assumption that the teaching of science will include a practical component. For instance, the School of Applied Sciences at Auckland University of Technology (AUT) offers a significant practical component within almost every course offered. This thesis explores the assumption that practical work should be included in the delivery of science courses. A range of views on the nature of science, the acquiring of knowledge and theories of learning are investigated, as well as the ways in which these may underpin the use of practical work as pedagogy in science education. The research described in this thesis took the form of a case study in which students in a range of science courses at AUT were asked to complete a questionnaire and a small number of respondents were then interviewed. Questionnaires were used to gather a large number of responses across a range of subject areas and a range of levels of study. Interviews were utilised to gather more in-depth responses. The data collated from the questionnaires and interviews was analysed thematically. Perhaps not surprisingly, the findings of this case study indicate overwhelming support by students for practical work. The dominant themes which emerged indicated that practical work not only supports learning and understanding in science, but also provides learning opportunities that classroom learning does not provide. The findings of this thesis would seem to support and justify the continued delivery of practical work in science courses. While the responses did not reveal how students believe practical work supports their learning and understanding, some respondents affirmed the less explicit aims of practical work in science education, such as the development of a sense of inquiry, the ability to problem solve and the ability to think critically. This then leads to the question as to whether practical work, as delivered in Applied Science courses at AUT, provides opportunities to potentially meet all of the aims which are expected and hoped for by students, the researcher and her colleagues. While this thesis establishes that students value highly the practical component in science courses, the need to further investigate the style of delivery of practical work to meet wider aims also emerged from this study

Mission possible: diatoms can be used to infer past duckweed (lemnoid Araceae) dominance in ponds

Compared to larger lakes, ponds have rarely been the focus of palaeoecological studies. A common feature of ponds, especially those subject to eutrophication, is mass surface coverings of lemnoid Araceae (duckweed) which have severe implications for ecological processes in small waterbodies, in particular lowered oxygen content. To help understand the implications of duckweed dominance for the long-term ecology of ponds, and to determine the potential for palaeoecological studies in ponds more generally, we develop a new diatom-based Lemna-indicator metric. Recent studies of diatom host-plant relationships have shown significant associations between duckweed and the epiphytes Lemnicola hungarica and Sellaphora saugerresii (formally known as Sellaphora seminulum). To determine the potential of these species as palaeo-indicators of long-term duckweed dynamics in ponds, we investigated the diatom composition of surface sediment assemblages in sets of duckweed and non-duckweed-dominated ponds in Norfolk, eastern England. In addition, we undertook diatom analysis of two cores from a small farmland pond (Bodham Rail Pit) subject to a known duckweed dominance event (1999–2005). Both L. hungarica and S. saugerresii were significant predictors of past Lemna dominance in the surface sediments. Further, in the core study, both diatom species accurately and closely tracked the documented “on–off” duckweed cycle. Our study suggests huge potential for using ponds in palaeoecological studies and for diatom-based investigations of floating plant histories

An analysis of the SADC tariff phasedown on Agriculture trade in Zimbabwe

As part of the integration process, SADC member states adopted a trade resolution in August 1996 to establish a Free Trade Area by 2008. It was expected that Zimbabwe would use the phase down period, to strategize and align herself for the Free Trade Area. While it is evidently noticeable that the country has overall fulfilled its obligations to reduce tariffs on a yearly basis, analysis of Zimbabwe’s revenue patterns does not however reflect such a view. Zimbabwe’s tariff phase down period does not show significant responses to the tariff phase downs implemented from the year 2000 to 2007

The role of IPR on maize output in Zimbabwe

This paper seeks to ascertain the role of intellectual property rights (IPR) on Zimbabwe’s maize output. Specific focus is given to the role of article 27 of the Trade Related Intellectual Property Rights (TRIPS) agreement as well as the Convention of Biological Diversity (CBD) in influencing maize output in Zimbabwe. While there has been an appreciation of IPR legislation attracting investments, the Zimbabwean government has found no need of revisiting some of this legislation. This is demonstrated by how some of the pieces of legislation have been left idle for long periods of time. From theory, the availability and supply of maize seed influence farmer’s production decisions, which in turn reflect total output of maize. However output data of maize production for the period 1994 to 2008 seem not to support this assertion. The need for a grassroots founded framework model on intellectual property rights in maize production is long overdue for the country. Such a framework allows for a general direction that enables appropriate policies to be established in addressing challenges embedded within the current scenario. In the interest of local communities, it is necessary that indigenous farm knowledge and processes be protected as well

The role of IPR on maize output in Zimbabwe

This paper seeks to ascertain the role of intellectual property rights (IPR) on Zimbabwe’s maize output. Specific focus is given to the role of article 27 of the Trade Related Intellectual Property Rights (TRIPS) agreement as well as the Convention of Biological Diversity (CBD) in influencing maize output in Zimbabwe. While there has been an appreciation of IPR legislation attracting investments, the Zimbabwean government has found no need of revisiting some of this legislation. This is demonstrated by how some of the pieces of legislation have been left idle for long periods of time. From theory, the availability and supply of maize seed influence farmer’s production decisions, which in turn reflect total output of maize. However output data of maize production for the period 1994 to 2008 seem not to support this assertion. The need for a grassroots founded framework model on intellectual property rights in maize production is long overdue for the country. Such a framework allows for a general direction that enables appropriate policies to be established in addressing challenges embedded within the current scenario. In the interest of local communities, it is necessary that indigenous farm knowledge and processes be protected as well