title: The effects of wood on stream habitat and native fish assemblages in New Zealand

authors: Baillie, Brenda Robin

subjects: wood

abstract: Historic deforestation has deprived many river systems of their natural wood loadings. To study the effects of the loss of wood from waterways, a field trial was conducted in three small forested streams in New Zealand. The objectives were to (i) examine differences in fish assemblages among wooded pools (where wood provided cover), open pools and riffles and (ii) measure the effects of wood removal on channel morphology and fish assemblages. In the first part of the study, no significant differences were found in total fish density among the three habitats. However, total fish biomass was significantly higher in wooded pools (64% of total fish biomass) compared with open pools and riffles. Mean density and biomass of banded kokopu (Galaxias fasciatus) and mean biomass of longfin eel (Anguilla dieffenbachii) were highest in wooded pools, whereas the density and biomass of bluegill bully (Gobiomorphus hubbsi) and torrentfish (Cheimarrichthys fosteri) were highest in riffles. In the second part of the study, wood was removed from a 200-m section (treatment) in each stream, significantly reducing pool area and increasing the proportion of channel area and length in riffles. At the habitat scale, banded kokopu and large longfin eel were the two species mostly affected by wood removal. At the reach scale, banded kokopu biomass was significantly lower in the treatment sections. Although wooded pools were a small portion of total habitat, they provided important habitat for two of New Zealand's larger native fish taxa.

text: The effects of wood on stream habitat and native fish assemblages in New Zealand Historic deforestation has deprived many river systems of their natural wood loadings. To study the effects of the loss of wood from waterways, a field trial was conducted in three small forested streams in New Zealand. The objectives were to (i) examine differences in fish assemblages among wooded pools (where wood provided cover), open pools and riffles and (ii) measure the effects of wood removal on channel morphology and fish assemblages. In the first part of the study, no significant differences were found in total fish density among the three habitats. However, total fish biomass was significantly higher in wooded pools (64% of total fish biomass) compared with open pools and riffles. Mean density and biomass of banded kokopu (Galaxias fasciatus) and mean biomass of longfin eel (Anguilla dieffenbachii) were highest in wooded pools, whereas the density and biomass of bluegill bully (Gobiomorphus hubbsi) and torrentfish (Cheimarrichthys fosteri) were highest in riffles. In the second part of the study, wood was removed from a 200-m section (treatment) in each stream, significantly reducing pool area and increasing the proportion of channel area and length in riffles. At the habitat scale, banded kokopu and large longfin eel were the two species mostly affected by wood removal. At the reach scale, banded kokopu biomass was significantly lower in the treatment sections. Although wooded pools were a small portion of total habitat, they provided important habitat for two of New Zealand's larger native fish taxa.

year: 2013

title: Unbounded knowledge acquisition based upon mutual information in dependent questions

authors: Smith, Tony C.

subjects: computer science

abstract: This paper describes an experimental system for knowledge acquisition based on a general framework exemplified in the game of twenty questions. A sequence of propositional questions is put to the user in an attempt to uncover some hidden concept, and the answers are used to expand and refine the system’s knowledge of the world. Previous systems adopting this framework typically represent knowledge as a matrix of truth values or weights that relate entities to attributes—such that if the hidden concept is “a bird”, for example, then the answer to a question about whether the target entity can fly is based on the extent to which “flying” is generally attributable to “a bird” as measured by the value in the matrix element indexed by the attribute-entity pair. Our system adopts a subtly different approach wherein knowledge is a measure of the extent to which answers to pairs of questions are co-dependent. Thus, knowledge about birds being able to fly is captured by the mutual information in the answers to a pair of questions like “Can it fly?” and “Is it a bird?”. We present a case that this offers a practical and epistemologically sound basis for acquiring knowledge.

text: Unbounded knowledge acquisition based upon mutual information in dependent questions This paper describes an experimental system for knowledge acquisition based on a general framework exemplified in the game of twenty questions. A sequence of propositional questions is put to the user in an attempt to uncover some hidden concept, and the answers are used to expand and refine the system’s knowledge of the world. Previous systems adopting this framework typically represent knowledge as a matrix of truth values or weights that relate entities to attributes—such that if the hidden concept is “a bird”, for example, then the answer to a question about whether the target entity can fly is based on the extent to which “flying” is generally attributable to “a bird” as measured by the value in the matrix element indexed by the attribute-entity pair. Our system adopts a subtly different approach wherein knowledge is a measure of the extent to which answers to pairs of questions are co-dependent. Thus, knowledge about birds being able to fly is captured by the mutual information in the answers to a pair of questions like “Can it fly?” and “Is it a bird?”. We present a case that this offers a practical and epistemologically sound basis for acquiring knowledge.

year: 2011

title: Brown bodies, white coats: Postcolonialism, Māori women, and science

authors: McKinley, Elizabeth

abstract: This project investigates the historical construction of 'Māori woman' and the constitution of the subjectivities of Maori women scientists today. The central question that is raised by the thesis is 'Do discourses of 'race' and gender found in Enlightenment science at the time of Aotearoa New Zealand's colonization continue to affect the contemporary subjectivity of Māori women scientists, and if so, how?' I have used literary historical techniques and feminist narrative interviews to collect the research data. Deconstruction, and its technique of 'double reading', has been applied through out the thesis to both the literary historical texts (imperial archives) and the transcripts of the interviews. I have argued that a poststructuralist view of the 'splitting the subject' to enable multiple positions must be read alongside the postcolonial view of a contemporary 'colonized subject' of an already 'split' subjectivity. 
This thesis is divided into two sections. Section A investigates Māori women as the objects of science. I argue that in Aotearoa New Zealand journeys of discovery and colonization were also scientific journeys that brought 'Māori woman' under the intellectual control of the emerging 'scientific' academy. At the same time, drawing on the 'imperial archives', I show that stereotypical signifiers are incorporated within scientific discourses and shape the fictions that these texts represent. In Section B I draw on open-ended interviews with 16 Māori women scientists who were asked to discuss their identity in relation to their schooling and workplaces. I explore the conditions by which the subject 'Māori women scientist' emerges and how the Maori women experience these conditions in relation to how they see themselves. I conclude by arguing that the identity of 'Māori woman scientist' appears to be 'impossible fiction' due to the fragmented nature of the sign - 'Māori, 'woman' and 'scientist' - that can be 'traced' to the historical construction of the signs.

text: Brown bodies, white coats: Postcolonialism, Māori women, and science This project investigates the historical construction of 'Māori woman' and the constitution of the subjectivities of Maori women scientists today. The central question that is raised by the thesis is 'Do discourses of 'race' and gender found in Enlightenment science at the time of Aotearoa New Zealand's colonization continue to affect the contemporary subjectivity of Māori women scientists, and if so, how?' I have used literary historical techniques and feminist narrative interviews to collect the research data. Deconstruction, and its technique of 'double reading', has been applied through out the thesis to both the literary historical texts (imperial archives) and the transcripts of the interviews. I have argued that a poststructuralist view of the 'splitting the subject' to enable multiple positions must be read alongside the postcolonial view of a contemporary 'colonized subject' of an already 'split' subjectivity. 
This thesis is divided into two sections. Section A investigates Māori women as the objects of science. I argue that in Aotearoa New Zealand journeys of discovery and colonization were also scientific journeys that brought 'Māori woman' under the intellectual control of the emerging 'scientific' academy. At the same time, drawing on the 'imperial archives', I show that stereotypical signifiers are incorporated within scientific discourses and shape the fictions that these texts represent. In Section B I draw on open-ended interviews with 16 Māori women scientists who were asked to discuss their identity in relation to their schooling and workplaces. I explore the conditions by which the subject 'Māori women scientist' emerges and how the Maori women experience these conditions in relation to how they see themselves. I conclude by arguing that the identity of 'Māori woman scientist' appears to be 'impossible fiction' due to the fragmented nature of the sign - 'Māori, 'woman' and 'scientist' - that can be 'traced' to the historical construction of the signs.

year: 2003