title: In situ collection and preservation of intact Microcystis colonies to assess population diversity and microcystin quotas

authors: Puddick, Jonathan

subjects: Science & Technology

abstract: Understanding of colony specific properties of cyanobacteria in the natural environment has been challenging because sampling methods disaggregate colonies and there are often delays before they can be isolated and preserved. Microcystis is a ubiquitous cyanobacteria that forms large colonies in situ and often produces microcystins, a potent hepatotoxin. In the present study a new cryo-sampling technique was used to collect intact Microcystis colonies in situ by embedding them in a sheet of ice. Thirty-two of these Microcystis colonies were investigated with image analysis, liquid chromatography-mass spectrometry, quantitative polymerase chain reaction and high-throughput sequencing to assess their volume, microcystin quota and internal transcribed spacer (ITS) genotype diversity. Microcystin quotas were positively correlated to colony volume (R² = 0.32; p = 0.004). Individual colonies had low Microcystis ITS genotype diversity and one ITS operational taxonomic unit predominated in all samples. This study demonstrates the utility of the cryo-sampling method to enhance the understanding of colony-specific properties of cyanobacteria with higher precision than previously possible.

text: In situ collection and preservation of intact Microcystis colonies to assess population diversity and microcystin quotas Understanding of colony specific properties of cyanobacteria in the natural environment has been challenging because sampling methods disaggregate colonies and there are often delays before they can be isolated and preserved. Microcystis is a ubiquitous cyanobacteria that forms large colonies in situ and often produces microcystins, a potent hepatotoxin. In the present study a new cryo-sampling technique was used to collect intact Microcystis colonies in situ by embedding them in a sheet of ice. Thirty-two of these Microcystis colonies were investigated with image analysis, liquid chromatography-mass spectrometry, quantitative polymerase chain reaction and high-throughput sequencing to assess their volume, microcystin quota and internal transcribed spacer (ITS) genotype diversity. Microcystin quotas were positively correlated to colony volume (R² = 0.32; p = 0.004). Individual colonies had low Microcystis ITS genotype diversity and one ITS operational taxonomic unit predominated in all samples. This study demonstrates the utility of the cryo-sampling method to enhance the understanding of colony-specific properties of cyanobacteria with higher precision than previously possible.

year: 2019

title: A map of the nanoworld: Sizing up the science, politics and business of the infinitesimal

authors: Munshi, Debashish

subjects: nanotechnology

abstract: Mapping out the eight main nodes of nanotechnology discourse that have emerged in the past decade, we explore how various scientific, social, and ethical islands of discussion have developed, been recognized, and are being continually renegotiated. We do so by (1) identifying the ways in which scientists, policy makers, entrepreneurs, educators, and environmental groups draw boundaries on issues relating to nanotechnology; (2) describing concisely the perspectives from which these boundaries are drawn; and (3) exploring how boundaries on nanotechnology are marked and negotiated through contestations of power among various nodes of nanotechnology discourse.

text: A map of the nanoworld: Sizing up the science, politics and business of the infinitesimal Mapping out the eight main nodes of nanotechnology discourse that have emerged in the past decade, we explore how various scientific, social, and ethical islands of discussion have developed, been recognized, and are being continually renegotiated. We do so by (1) identifying the ways in which scientists, policy makers, entrepreneurs, educators, and environmental groups draw boundaries on issues relating to nanotechnology; (2) describing concisely the perspectives from which these boundaries are drawn; and (3) exploring how boundaries on nanotechnology are marked and negotiated through contestations of power among various nodes of nanotechnology discourse.

year: 2007

title: My responsibility in the face of mass extinction

authors: Gray-Sharp, Katarina

subjects: autoethnography

abstract: Extinction is the “irreversible condition of a species or other group of organisms having no living representatives in the wild, which follows the death of the last surviving individual of that species or group” (Hine and Martin 2015g, para. 1). Mass extinctions are extinctions of the greatest magnitude, occurring “when many diverse groups of organisms become extinct over short periods of time” (Condie 2011, 250). These “are not step-events but rather a step into a prolonged alternative global ecosystem state” (Hull 2015, R941). Five mass extinctions have previously been recorded. A sixth has begun. Humans are the cause of the latest episode.

This thesis develops an Indigenous, non-agential conception of responsibility for considering an ethical problem of wide consequence. Founded in mātauranga Māori and recalling the work of Emmanuel Levinas, it applies Kaupapa Māori autoethnography, narrative, and conceptual analyses alongside exegeses and a replication study. Investigations of responsibility across various positions are encountered: those found in place and polity, those made as visitor and the commanded, those gifted as inherited erudition and in the suffering-with. Now facing the last structural violence, what is my responsibility?

text: My responsibility in the face of mass extinction Extinction is the “irreversible condition of a species or other group of organisms having no living representatives in the wild, which follows the death of the last surviving individual of that species or group” (Hine and Martin 2015g, para. 1). Mass extinctions are extinctions of the greatest magnitude, occurring “when many diverse groups of organisms become extinct over short periods of time” (Condie 2011, 250). These “are not step-events but rather a step into a prolonged alternative global ecosystem state” (Hull 2015, R941). Five mass extinctions have previously been recorded. A sixth has begun. Humans are the cause of the latest episode.

This thesis develops an Indigenous, non-agential conception of responsibility for considering an ethical problem of wide consequence. Founded in mātauranga Māori and recalling the work of Emmanuel Levinas, it applies Kaupapa Māori autoethnography, narrative, and conceptual analyses alongside exegeses and a replication study. Investigations of responsibility across various positions are encountered: those found in place and polity, those made as visitor and the commanded, those gifted as inherited erudition and in the suffering-with. Now facing the last structural violence, what is my responsibility?

year: 2021