337 research outputs found
Studies relating to the population dynamics of the European badger (Meles meles) in Ireland
European badgers (Meles meles) are an important part of the Irish ecosystem; they are a component of Ireland’s native fauna and are afforded protection by national and international laws. The species is also a reservoir host for bovine tuberculosis (bTB) and implicated in the epidemiology of bTB in cattle. Due to this latter point, badgers have been culled in the Republic of Ireland (ROI) in areas where persistent cattle bTB outbreaks exist. The population dynamics of badgers are therefore of great pure and applied interest. The studies within this thesis used large datasets and a number of analytical approaches to uncover essential elements of badger populations in the ROI. Furthermore, a review and meta-analysis of all available data on Irish badgers was completed to give a framework from which key knowledge gaps and future directions could be identified (Chapter 1).
One main finding suggested that badger densities are significantly reduced in areas of repeated culling, as revealed through declining trends in signs of activity (Chapter 2) and capture numbers (Chapter 2 and Chapter 3). Despite this, the trappability of badgers was shown to be lower than previously thought. This indicates that management programmes would require repeated long-term efforts to be effective (Chapter 4). Mark-recapture modelling of a population (sample area: 755km2) suggested that mean badger density was typical of continental European populations, but substantially lower than British populations (Chapter 4). Badger movement patterns indicated that most of the population exhibited site fidelity. Long-distance movements were also recorded, the longest of which (20.1km) was the greatest displacement of an Irish badger currently known (Chapter 5). The studies presented in this thesis allows for the development of more robust models of the badger population at national scales (see Future Directions). Through the use of large-scale datasets future models will facilitate informed sustainable planning for disease control
A comparison of the solvation power of the green solvent 2,2,5,5-tetramethyloxolane versus toluene via partition coefficients
2,2,5,5-tetramethyloxolane [previously published as 2,2,5,5-tetramethyltetrahydrofuran (TMTHF)] has recently been demonstrated as a greener and cleaner alternative to toluene in several applications. Assessing similarities in properties of toluene and 2,2,5,5-tetramethyloxolane is crucial for establishing this molecules potential to replace traditional non-polar organic solvents in the cleaner production of chemicals and materials. However, the Hansen solubility parameters (HSP) and Kamlet-Taft parameters (KT) give conflicting views on their similarities and differences, which necessitates a full comparative characterisation of the solvation environment of these two solvents. Such comparisons have been achieved through a direct and extensive determination of partition coefficients between each of the two solvents and water. The partition coefficients and Abraham's solvation parameter model have quantitatively clarified the similarities and differences in properties of 2,2,5,5-tetramethyloxolane and toluene. Solutes of high dipolarity and hydrogen-bond accepting ability tended to favour the aqueous phase in both systems, while large molar volume and high refractive indices favoured the organic phase. A significant difference between 2,2,5,5-tetramethyloxolane and toluene was observed for hydrogen-bond donating solutes. In general, such solutes strongly preferred the aqueous phase in the toluene/water system but preferred the organic phase in the 2,2,5,5-tetramethyloxolane/water system. This was due to the interaction of the protic solutes with the lone pairs of electrons on the ethereal oxygen of 2,2,5,5-tetramethyloxolane, a feature that is not present on toluene, and opens up new possibilities for applications of this sustainable solvent in liquid-liquid extraction, particularly in the isolation of natural products. As toluene is such an important solvent in the chemical industry, its replacement with a greener alternative such as 2,2,5,5-tetramethyloxolane would be hugely significant for cleaner synthesis, extractions and separations
A Hardware Analysis of Twisted Edwards Curves for an Elliptic Curve Cryptosystem
This paper presents implementation results of a reconfigurable elliptic curve processor defined over prime fields . We use this processor to compare a new algorithm for point addition and point doubling operations on the twisted Edwards curves, against a current standard algorithm in use, namely the Double-and-Add. Secure power analysis versions of both algorithms are also examined and compared. The algorithms are implemented on an FPGA, and the speed, area and power performance of each are then evaluated for various modes of circuit operation using parallel processing. To the authors\u27 knowledge, this work introduces the first documented FPGA implementation for computations on twisted Edwards curves over fields
Modelling Screwpile Installation Using the MPM
Screwpiles are, as the name suggests, piled foundations which are screwed into the ground. They provide restraint to both upwards and downward loading directions and are commonly used for light structures subject to overturning or wind loading, such as sign gantries at the sides of motorways. An EPSRC-funded project led by University of Dundee has recently started, with Durham and Southampton as partners, in which the use of screwpiles (individual or in groups) for offshore foundations is under investigation. At Durham, a numerical modelling framework based on the material point method (MPM) is being developed for the installation phase of a screwpile. The aim is to use the model to provide an accurate representation of the in situ ground conditions once the pile is installed, as during installation the ground is disturbed and any model that “wishes in place” a screwpile may not provide representative long-term performance predictions. Following modelling of installation, the soil state will be transferred to a standard finite element package for the subsequent modelling of in-service performance (the MPM being considered unnecessary and computationally expensive for this phase of the life of a screwpile). In this preliminary work, we present the development of features of this numerical tool to simulate the screwpile installation. These features include a moving mesh concept (both translation and rotation) and interface elements. The effectiveness of the algorithm is illustrated through simple examples
Reflecting on One Health in Action During the COVID-19 Response
The COVID-19 pandemic, a singular disruptive event in recent human history, has required rapid, innovative, coordinated and collaborative approaches to manage and ameliorate its worst impacts. However, the threat remains, and learning from initial efforts may benefit the response management in the future. One Health approaches to managing health challenges through multi-stakeholder engagement are underscored by an enabling environment. Here we describe three case studies from state (New South Wales, Australia), national (Ireland), and international (sub-Saharan Africa) scales which illustrate different aspects of One Health in action in response to the COVID-19 pandemic. In Ireland, a One Health team was assembled to help parameterise complex mathematical and resource models. In New South Wales, state authorities engaged collaboratively with animal health veterinarians and epidemiologists to leverage disease outbreak knowledge, expertise and technical and support structures for application to the COVID-19 emergency. The African One Health University Network linked members from health institutions and universities from eight countries to provide a virtual platform knowledge exchange on COVID-19 to support the response. Themes common to successful experiences included a shared resource base, interdisciplinary engagement, communication network strategies, and looking global to address local need. The One Health approaches used, particularly shared responsibility and knowledge integration, are benefiting the management of this pandemic and future One Health global challenges
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The scavenger receptor SCARF1 mediates apoptotic cell clearance and prevents autoimmunity
Clearance of apoptotic cells is critical for control of tissue homeostasis however the full range of receptor(s) on phagocytes responsible for recognition of apoptotic cells remains to be identified. Here we show that dendritic cells (DCs), macrophages and endothelial cells use scavenger receptor type F family member 1 (SCARF1) to recognize and engulf apoptotic cells via C1q. Loss of SCARF1 impairs uptake of apoptotic cells. Consequently, in SCARF1-deficient mice, dying cells accumulate in tissues leading to a lupus-like disease with the spontaneous generation of autoantibodies to DNA-containing antigens, immune cell activation, dermatitis and nephritis. The discovery of SCARF1 interactions with C1q and apoptotic cells provides insights into molecular mechanisms involved in maintenance of tolerance and prevention of autoimmune disease
FPGA Implementations of SHA-3 Candidates:CubeHash, Grøstl, L{\sc ane}, Shabal and Spectral Hash
Abstract: Hash functions are widely used in, and form an important part of many cryptographic protocols. Currently, a public competition is underway to find a new hash algorithm(s) for inclusion in the NIST Secure Hash Standard (SHA-3). Computational efficiency of the algorithms in hardware will form one of the evaluation criteria. In this paper, we focus on five of these candidate algorithms, namely CubeHash, Grøstl, L{\sc ane}, Shabal and Spectral Hash. Using Xilinx Spartan-3 and Virtex-5 FPGAs, we present architectures for each of these hash functions, and explore area-speed trade-offs in each design. The efficiency of various architectures for the five hash functions is compared in terms of throughput per unit area. To the best of the authors\u27 knowledge, this is the first such comparison of these SHA-3 candidates in the literature
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Genome-wide association study identifies 30 loci associated with bipolar disorder.
Bipolar disorder is a highly heritable psychiatric disorder. We performed a genome-wide association study (GWAS) including 20,352 cases and 31,358 controls of European descent, with follow-up analysis of 822 variants with P < 1 × 10-4 in an additional 9,412 cases and 137,760 controls. Eight of the 19 variants that were genome-wide significant (P < 5 × 10-8) in the discovery GWAS were not genome-wide significant in the combined analysis, consistent with small effect sizes and limited power but also with genetic heterogeneity. In the combined analysis, 30 loci were genome-wide significant, including 20 newly identified loci. The significant loci contain genes encoding ion channels, neurotransmitter transporters and synaptic components. Pathway analysis revealed nine significantly enriched gene sets, including regulation of insulin secretion and endocannabinoid signaling. Bipolar I disorder is strongly genetically correlated with schizophrenia, driven by psychosis, whereas bipolar II disorder is more strongly correlated with major depressive disorder. These findings address key clinical questions and provide potential biological mechanisms for bipolar disorder
The CUAVA-1 CubeSat—A Pathfinder Satellite for Remote Sensing and Earth Observation
In this paper we report a 3U CubeSat named CUAVA-1 designed by the ARC Training Centre for CubeSats, UAVs, and Their Applications (CUAVA). CUAVA, funded by the Australian Research Council, aims to train students, develop new instruments and technology to solve crucial problems, and help develop a world-class Australian industry in CubeSats, UAVs, and related products. The CUAVA-1 project is the Centre’s first CubeSat mission, following on from the 2 Australian satellites INSPIRE-2 and UNSW-EC0 CubeSats that launched in 2017. The mission is designed to serve as a precursor for a series of Earth observations missions and to demonstrate new technologies developed by our partners. We also intend to use the satellite to provide students hands-on experiences and to gain experience for our engineering, science and industry teams for future, more complex, missions
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