title: Best-first Decision Tree Learning

authors: Shi, Haijian

subjects: attribute

abstract: In best-first top-down induction of decision trees, the best split is added in each step (e.g. the split that maximally reduces the Gini index). This is in contrast to the standard depth-first traversal of a tree. The resulting tree will be the same, just how it is built is different. The objective of this project is to investigate whether it is possible to determine an appropriate tree size on practical datasets by combining best-first decision tree growth with cross-validation-based selection of the number of expansions that are performed. Pre-pruning, post-pruning, CART-pruning can be performed this way to compare.

text: Best-first Decision Tree Learning In best-first top-down induction of decision trees, the best split is added in each step (e.g. the split that maximally reduces the Gini index). This is in contrast to the standard depth-first traversal of a tree. The resulting tree will be the same, just how it is built is different. The objective of this project is to investigate whether it is possible to determine an appropriate tree size on practical datasets by combining best-first decision tree growth with cross-validation-based selection of the number of expansions that are performed. Pre-pruning, post-pruning, CART-pruning can be performed this way to compare.

year: 2007

title: Enhanced sample preparation for quantitation of microcystins by matrix-assisted laser desorption/ionisation–time of flight mass spectrometry

authors: Puddick, Jonathan

subjects: MALDI–TOF mass spectrometry

abstract: Introduction: Microcystins (MCs) are a group of cyanotoxins which pose a serious health threat when present in aquatic systems. Quantitative analysis of MCs by matrix-assisted laser desorption/ionisation–time of flight (MALDI–TOF) mass spectrometry has potential for the processing of large numbers of samples quickly and economically. The existing method uses an expensive internal standard and protocols that are incompatible with automated sample preparation and data acquisition.
Objective: To produce a MALDI–TOF sample preparation technique for the quantitation of MCs that not only maintains reproducibility and sensitivity, but is also compatible with an automated work-flow.
Methodology: Seven different MALDI–TOF sample preparations were assessed for signal reproducibility (coefficient of variation) and sensitivity (method detection limit) using a cost-effective internal standard (angiotensin I). The best preparation was then assessed for its quantitative performance using three different MC congeners ([Dha7] MC-LR, MC-RR and MC-YR).
Results: The sensitivity of six of the preparations was acceptable, as was the reproducibility for two thin-layer preparations performed on a polished steel target. Both thin-layer preparations could be used with a MALDI-TOF mass spectrometer that automatically acquires data, and one could be used in an automated sample preparation work-flow. Further investigation using the thin-layer spot preparation demonstrated that linear quantification of three different MC congeners was possible.
Conclusion: The study demonstrates that with different sample preparation methods and modern instrumentation, large numbers of samples can be analysed rapidly for MCs at low cost.

text: Enhanced sample preparation for quantitation of microcystins by matrix-assisted laser desorption/ionisation–time of flight mass spectrometry Introduction: Microcystins (MCs) are a group of cyanotoxins which pose a serious health threat when present in aquatic systems. Quantitative analysis of MCs by matrix-assisted laser desorption/ionisation–time of flight (MALDI–TOF) mass spectrometry has potential for the processing of large numbers of samples quickly and economically. The existing method uses an expensive internal standard and protocols that are incompatible with automated sample preparation and data acquisition.
Objective: To produce a MALDI–TOF sample preparation technique for the quantitation of MCs that not only maintains reproducibility and sensitivity, but is also compatible with an automated work-flow.
Methodology: Seven different MALDI–TOF sample preparations were assessed for signal reproducibility (coefficient of variation) and sensitivity (method detection limit) using a cost-effective internal standard (angiotensin I). The best preparation was then assessed for its quantitative performance using three different MC congeners ([Dha7] MC-LR, MC-RR and MC-YR).
Results: The sensitivity of six of the preparations was acceptable, as was the reproducibility for two thin-layer preparations performed on a polished steel target. Both thin-layer preparations could be used with a MALDI-TOF mass spectrometer that automatically acquires data, and one could be used in an automated sample preparation work-flow. Further investigation using the thin-layer spot preparation demonstrated that linear quantification of three different MC congeners was possible.
Conclusion: The study demonstrates that with different sample preparation methods and modern instrumentation, large numbers of samples can be analysed rapidly for MCs at low cost.

year: 2011

title: Marine inequality, borderization, and the radical potential of kinship

authors: McCormack, Fiona

subjects: Aquaculture

abstract: This article utilizes scholarship on borders to interpret the persistence of inequality in Indigenous seascapes, irrespective of moves to redress colonial wrongs or the growing anthropocenic recognition of human-nature interconnectedness. I examine border politics in the context of Māori claims for marine title and rights and the post-settlement development of aquaculture. Drawing on Harsha Walia’s concept of “border imperialism” and Achille Mbembe’s thesis on “borderization,” the article highlights the endurance of colonial forms alongside their neoliberal transformation into the enclosures and entrapments arising in the context of accelerated marine industrialization. By holding in tension the interconnection between marine environments and kinship, on one hand, and scholarship on borders, on the other, the article suggests that Indigenous Māori kinship, expanding through multiple layers of difference, constitutes a site of resistance that has the potential to refute the logic of borderization.

text: Marine inequality, borderization, and the radical potential of kinship This article utilizes scholarship on borders to interpret the persistence of inequality in Indigenous seascapes, irrespective of moves to redress colonial wrongs or the growing anthropocenic recognition of human-nature interconnectedness. I examine border politics in the context of Māori claims for marine title and rights and the post-settlement development of aquaculture. Drawing on Harsha Walia’s concept of “border imperialism” and Achille Mbembe’s thesis on “borderization,” the article highlights the endurance of colonial forms alongside their neoliberal transformation into the enclosures and entrapments arising in the context of accelerated marine industrialization. By holding in tension the interconnection between marine environments and kinship, on one hand, and scholarship on borders, on the other, the article suggests that Indigenous Māori kinship, expanding through multiple layers of difference, constitutes a site of resistance that has the potential to refute the logic of borderization.

year: 2025