title: Hindcasting cyanobacterial communities in Lake Okaro with germination experiments and genetic analyses

authors: Wood, Susanna A.

subjects: cyanobacteria

abstract: Cyanobacterial blooms are becoming increasingly prevalent worldwide. Sparse historic phytoplankton records often result in uncertainty as to whether bloom-forming species have always been present and are proliferating in response to eutrophication or climate change, or if there has been a succession of new arrivals through recent history. This study evaluated the relative efficacies of germination experiments and automated rRNA intergenic spacer analysis (ARISA) assays in identifying cyanobacteria in a sediment core and thus reconstructing the historical composition of cyanobacterial communities. A core (360 mm in depth) was taken in the central, undisturbed basin of Lake Okaro, New Zealand, a lake with a rapid advance of eutrophication and increasing cyanobacteria populations. The core incorporated a tephra from an 1886 volcanic eruption that served to delineate recent sediment deposition. ARISA and germination experiments successfully detected akinete-forming nostocaleans in sediment dating 120 bp and showed little change in Nostocales species structure over this time scale. Species that had not previously been documented in the lake were identified including Aphanizomenon issatschenkoi, a potent anatoxin-a producer. The historic composition of Chrococcales and Oscillatoriales was more difficult to reconstruct, potentially due to the relatively rapid degradation of vegetative cells within sediment.

text: Hindcasting cyanobacterial communities in Lake Okaro with germination experiments and genetic analyses Cyanobacterial blooms are becoming increasingly prevalent worldwide. Sparse historic phytoplankton records often result in uncertainty as to whether bloom-forming species have always been present and are proliferating in response to eutrophication or climate change, or if there has been a succession of new arrivals through recent history. This study evaluated the relative efficacies of germination experiments and automated rRNA intergenic spacer analysis (ARISA) assays in identifying cyanobacteria in a sediment core and thus reconstructing the historical composition of cyanobacterial communities. A core (360 mm in depth) was taken in the central, undisturbed basin of Lake Okaro, New Zealand, a lake with a rapid advance of eutrophication and increasing cyanobacteria populations. The core incorporated a tephra from an 1886 volcanic eruption that served to delineate recent sediment deposition. ARISA and germination experiments successfully detected akinete-forming nostocaleans in sediment dating 120 bp and showed little change in Nostocales species structure over this time scale. Species that had not previously been documented in the lake were identified including Aphanizomenon issatschenkoi, a potent anatoxin-a producer. The historic composition of Chrococcales and Oscillatoriales was more difficult to reconstruct, potentially due to the relatively rapid degradation of vegetative cells within sediment.

year: 2009

title: Implantable electrode structures and their RF effects in MRI machines

authors: McCabe, Steven Owen

subjects: Deep Brain Stimulator (DBS)

abstract: Medical implants incorporating long insulated conductors can generate a serious heating hazard to a patient undergoing a Magnetic Resonance Imaging (MRI) scan. Under the high-power RF field from an MRI machine, the conductors can behave as antennas and concentrate energy into small regions of body tissue, leading to excessive joule heating. Neurostimulator implants that employ long electrode leads such as those for Deep Brain Stimulation (DBS) and Spinal Cord Stimulation (SCS), are highly susceptible to this RF hazard. Patients with these implants are generally contraindicated from MRI.

This thesis examines the heating phenomenon and identifies a variety of methods to mitigate the hazard and gain implant leads MRI safety. Techniques such as thin insulation, surface roughening, and auxiliary decoy filars are explored, with the latter shown to be especially effective at providing safety. Designs are first modelled with electromagnetic simulation software then experimentally proven inside of a gelled saline phantom within a 3T MRI machine. A lab-based measurement method is also established to enable rapid low-cost testing of prototype lead designs.

text: Implantable electrode structures and their RF effects in MRI machines Medical implants incorporating long insulated conductors can generate a serious heating hazard to a patient undergoing a Magnetic Resonance Imaging (MRI) scan. Under the high-power RF field from an MRI machine, the conductors can behave as antennas and concentrate energy into small regions of body tissue, leading to excessive joule heating. Neurostimulator implants that employ long electrode leads such as those for Deep Brain Stimulation (DBS) and Spinal Cord Stimulation (SCS), are highly susceptible to this RF hazard. Patients with these implants are generally contraindicated from MRI.

This thesis examines the heating phenomenon and identifies a variety of methods to mitigate the hazard and gain implant leads MRI safety. Techniques such as thin insulation, surface roughening, and auxiliary decoy filars are explored, with the latter shown to be especially effective at providing safety. Designs are first modelled with electromagnetic simulation software then experimentally proven inside of a gelled saline phantom within a 3T MRI machine. A lab-based measurement method is also established to enable rapid low-cost testing of prototype lead designs.

year: 2019

title: Defence not defiance: The shaping of New Zealand’s volunteer force

authors: Clayton, Garry James

subjects: New Zealand Army history

abstract: In the latter half of the nineteenth century and the first decade of the twentieth New Zealand's land defences were primarily the responsibility of its Volunteer Force. This Force over a period of fifty-two years evolved from ill-considered vigilante bands to a well organised and disciplined Army. This thesis examines the evolution of this Volunteer Army in chronological sequence concentrating on the factors which shaped and developed it.
The preface provides a brief outline of this study on New Zealand's Volunteer Force. The thesis then presents the history of the Force in eight chapters. These chapters are in four basic divisions. The first section, of three chapters. examines the origins of the Force, its role in the New Zealand Wars and its subsequent development in the period of tenuous peace during the 1870's . The second section, comprising of two chapters only, examines the transformation of the Volunteers from a military body which primarily looked inward. into a Force which concentrated on protecting the nation's main ports. The third section , also comprising two chapters , then views the development of this coastal protection Force into a Colonial Army, able and willing to provide for the nation's own security as well as expeditionary units to· serve with the British Imperial Forces ·. The last Section, of one Chapter only, concentrates on the demise of Volunteering and the moves to compulsory military training. The conclusion then draws together the analytical threads of the thesis. 
As the thesis is extensive in its coverage of time, it is only possible to outline the very nature of Volunteering. It will be for Regimental Historians to show the uniqueness of each of the 658 different units that comprised the New Zealand Volunteer Force over its fifty-two years of existence. What this broad survey does do, however, is provide a unique window for the examination of the development of an embryonic Colonial Army in the context of a developing nation.

text: Defence not defiance: The shaping of New Zealand’s volunteer force In the latter half of the nineteenth century and the first decade of the twentieth New Zealand's land defences were primarily the responsibility of its Volunteer Force. This Force over a period of fifty-two years evolved from ill-considered vigilante bands to a well organised and disciplined Army. This thesis examines the evolution of this Volunteer Army in chronological sequence concentrating on the factors which shaped and developed it.
The preface provides a brief outline of this study on New Zealand's Volunteer Force. The thesis then presents the history of the Force in eight chapters. These chapters are in four basic divisions. The first section, of three chapters. examines the origins of the Force, its role in the New Zealand Wars and its subsequent development in the period of tenuous peace during the 1870's . The second section, comprising of two chapters only, examines the transformation of the Volunteers from a military body which primarily looked inward. into a Force which concentrated on protecting the nation's main ports. The third section , also comprising two chapters , then views the development of this coastal protection Force into a Colonial Army, able and willing to provide for the nation's own security as well as expeditionary units to· serve with the British Imperial Forces ·. The last Section, of one Chapter only, concentrates on the demise of Volunteering and the moves to compulsory military training. The conclusion then draws together the analytical threads of the thesis. 
As the thesis is extensive in its coverage of time, it is only possible to outline the very nature of Volunteering. It will be for Regimental Historians to show the uniqueness of each of the 658 different units that comprised the New Zealand Volunteer Force over its fifty-two years of existence. What this broad survey does do, however, is provide a unique window for the examination of the development of an embryonic Colonial Army in the context of a developing nation.

year: 1990