Simulation and Isolation Design for the TorPeDO Gravitational Sensor

The Torsion Pendulum Dual Oscillator (TorPeDO) is a dual torsion pendulum gravitational sensor under development by The Australian National University (ANU), Centre for Gravitational Astrophysics (CGA). This sensor uses measurements of differential rotation between two low resonant frequency (~26 mHz) torsion pendulums to infer transients in the curl of the gravitational potential field. Target sensitivity for the TorPeDO is set at 1.5 x 10^-14 rad/sqrt[Hz] at 0.1 Hz differential rotation between the two pendulums. This target sensitivity, combined with torsion pendulum resonant frequencies of ~ 26 mHz, aims to create an observation frequency band for gravitational sources between 30 mHz and 10 Hz. If this target sensitivity is achieved the proposed applications of TorPeDO sensor are wide ranging, with both scientific and practical applications. This thesis focuses upon the development of the TorPeDO for two primary applications: the detection of Newtonian noise sources, and detection of earthquakes by transients in the local gravitational potential field. A controls prototype for the TorPeDO sensor having already been fabricated, this thesis explores several design challenges that have arisen during its commissioning and operation. The initial chapters of this thesis focus on the simulation of the current prototype, and necessary steps required to mitigate environmentally induced mechanical disturbances to the system. These environmental factors, combined with technical noises source, limit on the sensitivity of the TorPeDO controls prototype. By examining a predictive Lagrangian mechanics based model of the TorPeDO, calculated in a full three-dimensional Cartesian space, this thesis explores how cross-coupling facilitates the propagation of noise from several sources within the detector's design. Methods for mitigating the propagation of each potential noise source, both in the mechanics of the system and in the design of the controls architecture, are then proposed. As part of this examination, how the design of the TorPeDO's pendulums contributes to the range and antenna pattern of the TorPeDO detector is considered. Later chapters of this thesis focus upon the suppression of residual motion of the TorPeDO transducer suspension point to below 1.9 x 10^-10 m/sqrt[Hz] linear motion and 3.9 x 10^-12 rad/sqrt[Hz] rotational motion at 0.1 Hz using a novel seismic isolation chain design. This suspension point requirement is determined through the simulation as being required to ensure the sensor is not limited by seismic noise. The design and control of the proposed seismic isolation chain design is a wholly new system being fabricated and commissioned at the ANU because of the work presented here. Where possible, practical results arising from initial testing of the mechanics and control systems of this new isolation chain are presented alongside simulations to demonstrate the potential performance of the system. In the concluding chapters of this thesis proposals will be made for improvement of the TorPeDO sensor based upon the current state of the system and predictive modelling of the new seismic isolation chain design. This will provide the reader with a more complete picture of the current state of the TorPeDO sensor, the state of the system upon the completion of the seismic chain commissioning, and current ongoing avenues of development

Reliable Discrimination of 10 Ungulate Species Using High Resolution Melting Analysis of Faecal DNA

Identifying species occupying an area is essential for many ecological and conservation studies. Faecal DNA is a potentially powerful method for identifying cryptic mammalian species. In New Zealand, 10 species of ungulate (Order: Artiodactyla) have established wild populations and are managed as pests because of their impacts on native ecosystems. However, identifying the ungulate species present within a management area based on pellet morphology is unreliable. We present a method that enables reliable identification of 10 ungulate species (red deer, sika deer, rusa deer, fallow deer, sambar deer, white-tailed deer, Himalayan tahr, Alpine chamois, feral sheep, and feral goat) from swabs of faecal pellets. A high resolution melting (HRM) assay, targeting a fragment of the 12S rRNA gene, was developed. Species-specific primers were designed and combined in a multiplex PCR resulting in fragments of different length and therefore different melting behaviour for each species. The method was developed using tissue from each of the 10 species, and was validated in blind trials. Our protocol enabled species to be determined for 94% of faecal pellet swabs collected during routine monitoring by the New Zealand Department of Conservation. Our HRM method enables high-throughput and cost-effective species identification from low DNA template samples, and could readily be adapted to discriminate other mammalian species from faecal DNA

Origins and population genetics of sambar deer (Cervus unicolor) introduced to Australia and New Zealand

Context. Some populations of introduced species cause significant undesirable impacts but can also act as reservoirs for genetic diversity. Sambar deer (Cervus unicolor) are ‘Vulnerable’ in their native range and invasive in Australia and New Zealand. Genetic data can be used to determine whether these introduced populations might serve as genetic reservoirs for declining native populations and to identify spatial units for management. Aims. We aimed to identify the provenance of sambar deer in Australia and New Zealand, and to characterise their genetic diversity and population structure. Methods. We used mitochondrial control region sequences and 18 nuclear microsatellite loci of 24 New Zealand and 63 Australian sambar deer collected across continuous habitat in each location. We estimated genetic diversity and population differentiation by using pairwise FST, AMOVA, and STRUCTURE analyses. We compared our data with 27 previously published native and invasive range sequences to identify phylogenetic relationships. Key results. Sambar deer in Australia and New Zealand are genetically more similar to those in the west of the native range (South and Central Highlands of India, and Sri Lanka), than to those in the east (eastern India, and throughout Southeast Asia). Nuclear genetic diversity was lower than in the native range; only one mitochondrial haplotype was found in each introduced population. Australian and New Zealand sambar deer were genetically distinct but there was no population structure within either population. Conclusions. The genetic differences we identified between these two introduced populations at putatively neutral loci indicate that there also may be underlying diversity at functional loci. The lack of population genetic structure that we found within introduced populations suggests that individuals within these popula- tions do not experience barriers to dispersal across the areas sampled. Implications. Although genetic diversity is reduced in the introduced range compared with the native range, sambar deer in Australia and New Zealand harbour unique genetic variants that could be used to strengthen genetic diversity in populations under threat in the native range. The apparent high levels of gene flow across the areas we sampled suggest that localised control is unlikely to be effective in Australia and New Zealand

First imaging of corotating interaction regions using the STEREO spacecraft

Plasma parcels are observed propagating from the Sun out to the large coronal heights monitored by the Heliospheric Imagers (HI) instruments onboard the NASA STEREO spacecraft during September 2007. The source region of these out-flowing parcels is found to corotate with the Sun and to be rooted near the western boundary of an equatorial coronal hole. These plasma enhancements evolve during their propagation through the HI cameras’ fields of view and only becoming fully developed in the outer camera field of view. We provide evidence that HI is observing the formation of a Corotating Interaction Region(CIR) where fast solar wind from the equatorial coronal hole is interacting with the slow solar wind of the streamer belt located on the western edge of that coronal hole. A dense plasma parcel is also observed near the footpoint of the observed CIR at a distance less than 0.1AU from the Sun where fast wind would have not had time to catch up slow wind. We suggest that this low-lying plasma enhancement is a plasma parcel which has been disconnected from a helmet streamer and subsequently becomes embedded inside the corotating interaction region

Conceptual learning : the priority for higher education

The common sense notion of learning as the all-pervasive acquisition of new behaviour and knowledge, made vivid by experience, is an incomplete characterisation, because it assumes that the learning of behaviour and the learning of knowledge are indistinguishable, and that acquisition constitutes learning without reference to transfer. A psychological level of analysis is used to argue that conceptual learning should have priority in higher education

Kurt Lewin’s leadership studies and his legacy to social psychology: is there nothing as practical as a good theory?

This paper re-examines Kurt Lewin's classic leadership studies, using them as a concrete example to explore his wider legacy to social psychology. Lewin distinguished between advanced “Galileian” science, which was based on analysing particular examples, and backward “Aristotelian” science, which used statistical analyses. Close examination of the way Lewin wrote about the leadership studies reveals that he used the sort of binary, value-laden concepts that he criticised as “Aristotelian”. Such concepts, especially those of “democracy” and “autocracy”, affected the way that he analysed the results and the ways that later social scientists have understood, and misunderstood, the studies. It is argued that Lewin's famous motto—“there is nothing as practical as a good theory”—is too simple to fit the tensions between the leadership studies and his own views of what counts as good theory

The thing about replicas - why historic replicas matter

Reproduction of archaeological material was a significant and serious enterprise for antiquarians and museums in the long nineteenth century. Embedding many stories and embodying considerable past human energy, behind their creation, circulation, use and after-life lies a series of specific social networks and relationships that determined why, when and in what circumstances they were valued, or not. Summarising the context of their production, circulation and changing fortunes, this paper introduces the ways in which they are important and the specific benefits and aspects of a biographical approach to their study. Beyond the evidential, the study of existing replicas provides a historical and contemporary laboratory in which to explore the concepts of value and authenticity, and their application in cultural heritage and collections management, offering us a richer insight into the history of ourselves as archaeologists and curators

Reevaluating the imaging definition of tumor progression: perfusion MRI quantifies recurrent glioblastoma tumor fraction, pseudoprogression, and radiation necrosis to predict survival

INTRODUCTION: Contrast-enhanced MRI (CE-MRI) represents the current mainstay for monitoring treatment response in glioblastoma multiforme (GBM), based on the premise that enlarging lesions reflect increasing tumor burden, treatment failure, and poor prognosis. Unfortunately, irradiating such tumors can induce changes in CE-MRI that mimic tumor recurrence, so called post treatment radiation effect (PTRE), and in fact, both PTRE and tumor re-growth can occur together. Because PTRE represents treatment success, the relative histologic fraction of tumor growth versus PTRE affects survival. Studies suggest that Perfusion MRI (pMRI)–based measures of relative cerebral blood volume (rCBV) can noninvasively estimate histologic tumor fraction to predict clinical outcome. There are several proposed pMRI-based analytic methods, although none have been correlated with overall survival (OS). This study compares how well histologic tumor fraction and OS correlate with several pMRI-based metrics. METHODS: We recruited previously treated patients with GBM undergoing surgical re-resection for suspected tumor recurrence and calculated preoperative pMRI-based metrics within CE-MRI enhancing lesions: rCBV mean, mode, maximum, width, and a new thresholding metric called pMRI–fractional tumor burden (pMRI-FTB). We correlated all pMRI-based metrics with histologic tumor fraction and OS. RESULTS: Among 25 recurrent patients with GBM, histologic tumor fraction correlated most strongly with pMRI-FTB (r = 0.82; P < .0001), which was the only imaging metric that correlated with OS (P<.02). CONCLUSION: The pMRI-FTB metric reliably estimates histologic tumor fraction (i.e., tumor burden) and correlates with OS in the context of recurrent GBM. This technique may offer a promising biomarker of tumor progression and clinical outcome for future clinical trials

Implementing integrated measurements of essential biodiversity variables at a national scale

Funding: the Strategic Science Investment Funding for Crown Research Institutes from the Ministry of Business, Innovation and Employment.1. There is a global need for observation systems that deliver regular, timely data on state and trends in biodiversity, but few have been implemented, and fewer still at national scales. We describe the implementation of measurement of Essential Biodiversity Variables (EBVs) on an 8 km × 8 km grid throughout New Zealand, with multiple components of biodiversity (vegetation, birds, and some introduced mammals) measured simultaneously at each sample point. 2. Between 2011 and 2017, all public land was sampled nationally (ca. 1,350 points) and some private land (ca. 500 points). Synthetic appraisals of the state of New Zealand's biodiversity, not possible previously, can be derived from the first measurement of species distribution, population abundance, and taxonomic diversity EBVs. 3. Native bird counts (all species combined) were about 2.5 times greater per sample point in natural forests and shrublands than in non‐woody ecosystems, and native bird counts exceeded those of non‐native birds across all natural forests and shrublands. 4. Non‐native plants, birds, and mammals are invasive throughout, but high‐rainfall forested regions are least invaded, and historically deforested rain shadow regions are most invaded. 5. National reporting of terrestrial biodiversity across New Zealand's public land is established and becoming normalised, in the same manner as national and international reporting of human health and education statistics. The challenge is extending coverage across all private land. Repeated measurements of these EBVs, which began in 2017, will allow defensible estimates of biodiversity trends.Publisher PDFPeer reviewe