title: Understanding the response of nitrifying communities to disturbance in the mcmurdo dry valleys, Antarctica

authors: Monteiro, Maria R.

subjects: Science & Technology

abstract: © 2020 by the authors. Licensee MDPI, Basel, Switzerland. Polar ecosystems are generally limited in nitrogen (N) nutrients, and the patchy availability of N is partly determined by biological pathways, such as nitrification, which are carried out by distinctive prokaryotic functional groups. The activity and diversity of microorganisms are generally strongly influenced by environmental conditions. However, we know little of the attributes that control the distribution and activity of specific microbial functional groups, such as nitrifiers, in extreme cold environments and how they may respond to change. To ascertain relationships between soil geochemistry and the ecology of nitrifying microbial communities, we carried out a laboratory-based manipulative experiment to test the selective effect of key geochemical variables on the activity and abundance of ammonia-oxidizing communities in soils from the McMurdo Dry Valleys of Antarctica. We hypothesized that nitrifying communities, adapted to different environmental conditions within the Dry Valleys, will have distinct responses when submitted to similar geochemical disturbances. In order to test this hypothesis, soils from two geographically distant and geochemically divergent locations, Miers and Beacon Valleys, were incubated over 2 months under increased conductivity, ammonia concentration, copper concentration, and organic matter content. Amplicon sequencing of the 16S rRNA gene and transcripts allowed comparison of the response of ammonia-oxidizing Archaea (AOA) and ammonia-oxidizing Bacteria (AOB) to each treatment over time. This approach was combined with measurements of15NH4+ oxidation rates using15N isotopic additions. Our results showed a higher potential for nitrification in Miers Valley, where environmental conditions are milder relative to Beacon Valley. AOA exhibited better adaptability to geochemical changes compared to AOB, particularly to the increase in copper and conductivity. AOA were also the only nitrifying group found in Beacon Valley soils. This laboratorial manipulative experiment provided new knowledge on how nitrifying groups respond to changes on key geochemical variables of Antarctic desert soils, and we believe these results offer new insights on the dynamics of N cycling in these ecosystems.

text: Understanding the response of nitrifying communities to disturbance in the mcmurdo dry valleys, Antarctica © 2020 by the authors. Licensee MDPI, Basel, Switzerland. Polar ecosystems are generally limited in nitrogen (N) nutrients, and the patchy availability of N is partly determined by biological pathways, such as nitrification, which are carried out by distinctive prokaryotic functional groups. The activity and diversity of microorganisms are generally strongly influenced by environmental conditions. However, we know little of the attributes that control the distribution and activity of specific microbial functional groups, such as nitrifiers, in extreme cold environments and how they may respond to change. To ascertain relationships between soil geochemistry and the ecology of nitrifying microbial communities, we carried out a laboratory-based manipulative experiment to test the selective effect of key geochemical variables on the activity and abundance of ammonia-oxidizing communities in soils from the McMurdo Dry Valleys of Antarctica. We hypothesized that nitrifying communities, adapted to different environmental conditions within the Dry Valleys, will have distinct responses when submitted to similar geochemical disturbances. In order to test this hypothesis, soils from two geographically distant and geochemically divergent locations, Miers and Beacon Valleys, were incubated over 2 months under increased conductivity, ammonia concentration, copper concentration, and organic matter content. Amplicon sequencing of the 16S rRNA gene and transcripts allowed comparison of the response of ammonia-oxidizing Archaea (AOA) and ammonia-oxidizing Bacteria (AOB) to each treatment over time. This approach was combined with measurements of15NH4+ oxidation rates using15N isotopic additions. Our results showed a higher potential for nitrification in Miers Valley, where environmental conditions are milder relative to Beacon Valley. AOA exhibited better adaptability to geochemical changes compared to AOB, particularly to the increase in copper and conductivity. AOA were also the only nitrifying group found in Beacon Valley soils. This laboratorial manipulative experiment provided new knowledge on how nitrifying groups respond to changes on key geochemical variables of Antarctic desert soils, and we believe these results offer new insights on the dynamics of N cycling in these ecosystems.

year: 2020-03-13

title: Chief Amongst The Angels?  International Prosecutors And The Modernist Project

authors: Rogers, Damien Robert

subjects: International Criminal Law

abstract: This thesis argues that three successive generations of prosecutors—each of whom at some moment in time belong to a major institution designed specifically to enforce international criminal law—are best understood as agents of the law, politics and war.  By examining the relevant institutional arrangements, including formal prosecutorial mandates, the thesis recognises that these prosecutors play vital roles in the enforcement of international criminal law.  By critically examining prosecutorial performance during the pre-trial and trial phases this thesis contends, firstly, that these prosecutors are also political actors serving, unwittingly or otherwise, in the interests of economic liberalisation, expressed as neo-capitalism during the middle of the twentieth century or as neoliberalism in the late twentieth century.  By foregrounding the material and ideational conditions giving rise to those major enforcement institutions this thesis contends, secondly, that international prosecutors also help wage a mostly silent and largely unacknowledged war fought by proponents of various utopian movements.  In order to support these two main contentions the thesis situates the development of international criminal law and its major institutions as a significant temporality of a discourse against politico-cruelty, a term used here to refer to cruel acts committed as a means of achieving some substantive end.  It also contextualises the collective prosecutorial efforts within the project of modernity and, more specifically, what is described here as a politico-cultural civil war fought for control over that project.  Using international criminal law as a means of confronting humanity’s worst excesses and curbing modernity’s most violent pathologies, international prosecutors of war crimes, crimes against humanity, crimes of genocide and crimes of aggression might represent the vanguard in the quest for international criminal justice and be regarded by many as featuring among humanity’s better angels.  Indeed, they might well be characterised in world affairs as chief amongst the angels.  But, at the same time, these politico-legal actors, whose mandates are derived from, and re-inscribe, particular configurations of power emerging in the aftermath of global conflict, need to be recognised as the auxiliary combatants of those seeking to maintain their control over the modernist project.

text: Chief Amongst The Angels?  International Prosecutors And The Modernist Project This thesis argues that three successive generations of prosecutors—each of whom at some moment in time belong to a major institution designed specifically to enforce international criminal law—are best understood as agents of the law, politics and war.  By examining the relevant institutional arrangements, including formal prosecutorial mandates, the thesis recognises that these prosecutors play vital roles in the enforcement of international criminal law.  By critically examining prosecutorial performance during the pre-trial and trial phases this thesis contends, firstly, that these prosecutors are also political actors serving, unwittingly or otherwise, in the interests of economic liberalisation, expressed as neo-capitalism during the middle of the twentieth century or as neoliberalism in the late twentieth century.  By foregrounding the material and ideational conditions giving rise to those major enforcement institutions this thesis contends, secondly, that international prosecutors also help wage a mostly silent and largely unacknowledged war fought by proponents of various utopian movements.  In order to support these two main contentions the thesis situates the development of international criminal law and its major institutions as a significant temporality of a discourse against politico-cruelty, a term used here to refer to cruel acts committed as a means of achieving some substantive end.  It also contextualises the collective prosecutorial efforts within the project of modernity and, more specifically, what is described here as a politico-cultural civil war fought for control over that project.  Using international criminal law as a means of confronting humanity’s worst excesses and curbing modernity’s most violent pathologies, international prosecutors of war crimes, crimes against humanity, crimes of genocide and crimes of aggression might represent the vanguard in the quest for international criminal justice and be regarded by many as featuring among humanity’s better angels.  Indeed, they might well be characterised in world affairs as chief amongst the angels.  But, at the same time, these politico-legal actors, whose mandates are derived from, and re-inscribe, particular configurations of power emerging in the aftermath of global conflict, need to be recognised as the auxiliary combatants of those seeking to maintain their control over the modernist project.

year: 2016

title: Reconnection with DNA: Policy and issues with direct-to-consumer DNA testing for indigenous Māori identity reclamation

authors: Turanga, Karen

abstract: The disconnection of tangata whenua (indigenous people born of the land) impacts all social determinants. A clear sense of identity and connection to the land and culture is an important solution to this problem. The purpose of this research is to share a personal and whānau (family group) story of using direct-to-consumer (DTC) autosomal DNA genetic testing (GT) to determine ancestry and show others a potential path forward to identity reclamation. To fulfil this purpose and explain the policy context, the research examines historical assimilation policies of closed cross-cultural adoption, and the possibilities DNA technology offers for whakapapa (genealogy, lineage descent, family history) reconnection. This includes addressing two key research questions: How does DTC-GT facilitate reconnection to Māori identity and whakapapa for cross-cultural adoptees? What are the short, medium and long-term risks and advantages of DTC autosomal DTC-GT testing for iwi Māori? A bricolage methodology frames this research and draws on kaupapa Māori (Māori approach, principles, and ideology), autoethnography, and interpretive phenomenology, which are used to analyse academic commentary and key policy decisions. An autoethnographic layered practice approach presents insights and key findings by combining personal narratives with various media types, academic research, policy documents and popular culture. The research highlights how the implicit processes of policy-led assimilation and colonisation still need to be challenged today. Existing literature has identified the importance of giving Māori pathways to reconnect with their identity. The personal story shared explains how DNA technology offers a way to do that, but the research completed for this thesis demonstrates this approach has serious risks and limitations that require consideration before utilising this technology.

text: Reconnection with DNA: Policy and issues with direct-to-consumer DNA testing for indigenous Māori identity reclamation The disconnection of tangata whenua (indigenous people born of the land) impacts all social determinants. A clear sense of identity and connection to the land and culture is an important solution to this problem. The purpose of this research is to share a personal and whānau (family group) story of using direct-to-consumer (DTC) autosomal DNA genetic testing (GT) to determine ancestry and show others a potential path forward to identity reclamation. To fulfil this purpose and explain the policy context, the research examines historical assimilation policies of closed cross-cultural adoption, and the possibilities DNA technology offers for whakapapa (genealogy, lineage descent, family history) reconnection. This includes addressing two key research questions: How does DTC-GT facilitate reconnection to Māori identity and whakapapa for cross-cultural adoptees? What are the short, medium and long-term risks and advantages of DTC autosomal DTC-GT testing for iwi Māori? A bricolage methodology frames this research and draws on kaupapa Māori (Māori approach, principles, and ideology), autoethnography, and interpretive phenomenology, which are used to analyse academic commentary and key policy decisions. An autoethnographic layered practice approach presents insights and key findings by combining personal narratives with various media types, academic research, policy documents and popular culture. The research highlights how the implicit processes of policy-led assimilation and colonisation still need to be challenged today. Existing literature has identified the importance of giving Māori pathways to reconnect with their identity. The personal story shared explains how DNA technology offers a way to do that, but the research completed for this thesis demonstrates this approach has serious risks and limitations that require consideration before utilising this technology.

year: 2025-08-08