title: Eating behaviour regulation in Zebrafish (Danio rerio): a comparative analysis

authors: Ahmadi, Ramtin

subjects: Zebrafish

abstract: The structure, function, and tissue specific expression profiles of neuropeptides involved in regulating eating behaviour are well researched in mammals, the corresponding literature on fish homologs however is scarce. The work presented here endeavoured to characterise the full coding sequences of peptide homologs in zebrafish as well as the expression profiles of said peptides under different energy states to elucidate their function in fish. Zebrafish were chosen as a model to represent fish species as they are amenable to molecular study. Conducting a literature and TBLASTn search, genes were identified in zebrafish that are known to be involved in affecting appetite and satiety in other vertebrates. Comparison of the translated sequences of these genes against fish and other vertebrates provided confidence in the identity of AGRP, GHRL, POMCb, CART1, CART3, and CART4 and all genes showed homology against mammalian transcripts through structural and syntenic comparison. RACE synthesis of the full coding sequence of these genes was attempted from isolated brain mRNA but only resulted in the production of a partial 3’ sequence for CART1 and CART4 which showed high identity against the predicted nucleotide but not the translated sequence. To observe the functional properties of a suite of genes, a qPCR analysis of the expression profiles of AGRP, GHRL, POMCa, POMCb, CART1, CART2, CART3, CART4, OXT, NPY, and AVPwas undertaken  in 24 hour fasted zebrafish. The results were comparable to both other fish and mammals as AGRP was orexigenically upregulated in fasted zebrafish, while POMCb and OXT were anorexigenically downregulated. This is the first time that an expression study has been conducted across all of these genes together in a single species and, while the results are preliminary, they outline that the simultaneous analysis of the many genes thought to be involved in eating behaviour is a viable approach to discovering the functional roles of the range of genes, their interaction with each other, and how that relates to eating behaviour and provides some confidence in use of zebrafish as a model to highlight this.

text: Eating behaviour regulation in Zebrafish (Danio rerio): a comparative analysis The structure, function, and tissue specific expression profiles of neuropeptides involved in regulating eating behaviour are well researched in mammals, the corresponding literature on fish homologs however is scarce. The work presented here endeavoured to characterise the full coding sequences of peptide homologs in zebrafish as well as the expression profiles of said peptides under different energy states to elucidate their function in fish. Zebrafish were chosen as a model to represent fish species as they are amenable to molecular study. Conducting a literature and TBLASTn search, genes were identified in zebrafish that are known to be involved in affecting appetite and satiety in other vertebrates. Comparison of the translated sequences of these genes against fish and other vertebrates provided confidence in the identity of AGRP, GHRL, POMCb, CART1, CART3, and CART4 and all genes showed homology against mammalian transcripts through structural and syntenic comparison. RACE synthesis of the full coding sequence of these genes was attempted from isolated brain mRNA but only resulted in the production of a partial 3’ sequence for CART1 and CART4 which showed high identity against the predicted nucleotide but not the translated sequence. To observe the functional properties of a suite of genes, a qPCR analysis of the expression profiles of AGRP, GHRL, POMCa, POMCb, CART1, CART2, CART3, CART4, OXT, NPY, and AVPwas undertaken  in 24 hour fasted zebrafish. The results were comparable to both other fish and mammals as AGRP was orexigenically upregulated in fasted zebrafish, while POMCb and OXT were anorexigenically downregulated. This is the first time that an expression study has been conducted across all of these genes together in a single species and, while the results are preliminary, they outline that the simultaneous analysis of the many genes thought to be involved in eating behaviour is a viable approach to discovering the functional roles of the range of genes, their interaction with each other, and how that relates to eating behaviour and provides some confidence in use of zebrafish as a model to highlight this.

year: 2014

title: Classification and regression algorithms for WEKA implemented in Python

authors: Beckham, Christopher J.

subjects: Computer Science

abstract: WEKA is a popular machine learning workbench written in Java that allows users to easily classify, process, and explore data. There are many ways WEKA can be used: through the WEKA Explorer, users can visualise data, train classifiers and examine performance metrics; in the WEKA Experimenter, datasets and algorithms can be compared in an automated fashion; or, it can simply be invoked on the command-line or used as an external library in a Java project.

text: Classification and regression algorithms for WEKA implemented in Python WEKA is a popular machine learning workbench written in Java that allows users to easily classify, process, and explore data. There are many ways WEKA can be used: through the WEKA Explorer, users can visualise data, train classifiers and examine performance metrics; in the WEKA Experimenter, datasets and algorithms can be compared in an automated fashion; or, it can simply be invoked on the command-line or used as an external library in a Java project.

year: 2015-10

title: Listening to the voices of Year 13 Māori students: A case study in a New Zealand secondary school

authors: Kay, Joan-Marie

subjects: Maori Achievement

abstract: This research focuses on listening to the voices of Year 13 academically successful Māori students in a large, urban, mainstream, co-educational, decile 4, New Zealand secondary school. Traditionally, researchers have tended to emphasise the poor academic performance of Māori students in New Zealand. In contrast, this qualitative case study, however, seeks to understand what influences and motivates the academically successful Year 13 Māori students who have gained the National Certificate of Educational Achievement (NCEA) Level 2 and who returned to school to study for NCEA Level 3.

Semi structured interviews as conversations with all thirteen Māori students who had achieved NCEA Level 2 formed the basis of this research. Five of their parents, seven of their teachers and the principal were also interviewed.

The findings show that these students all stress the importance of their family, in particular, one family member or significant adult in their lives who valued education and supported the student, influencing and encouraging their motivation and self-efficacy. Building positive relationships with their teachers was the next strongest influence on their academic success followed closely by the positive influence of their friends. Self-motivation was mainly extrinsic. The students perceived that the principal had little effect on their individual achievement.

The teachers also acknowledge the importance of building positive relationships with their students and acknowledge the benefits of the reflective practice provided by the Te Kotahitanga project in highlighting this factor.

The findings suggest the excellent initiatives currently taking place in the school need to be continued or strengthened and that further interventions which target particular Māori students, rather than are global across the school, should be introduced.

text: Listening to the voices of Year 13 Māori students: A case study in a New Zealand secondary school This research focuses on listening to the voices of Year 13 academically successful Māori students in a large, urban, mainstream, co-educational, decile 4, New Zealand secondary school. Traditionally, researchers have tended to emphasise the poor academic performance of Māori students in New Zealand. In contrast, this qualitative case study, however, seeks to understand what influences and motivates the academically successful Year 13 Māori students who have gained the National Certificate of Educational Achievement (NCEA) Level 2 and who returned to school to study for NCEA Level 3.

Semi structured interviews as conversations with all thirteen Māori students who had achieved NCEA Level 2 formed the basis of this research. Five of their parents, seven of their teachers and the principal were also interviewed.

The findings show that these students all stress the importance of their family, in particular, one family member or significant adult in their lives who valued education and supported the student, influencing and encouraging their motivation and self-efficacy. Building positive relationships with their teachers was the next strongest influence on their academic success followed closely by the positive influence of their friends. Self-motivation was mainly extrinsic. The students perceived that the principal had little effect on their individual achievement.

The teachers also acknowledge the importance of building positive relationships with their students and acknowledge the benefits of the reflective practice provided by the Te Kotahitanga project in highlighting this factor.

The findings suggest the excellent initiatives currently taking place in the school need to be continued or strengthened and that further interventions which target particular Māori students, rather than are global across the school, should be introduced.

year: 2008