William Yaxley : the arrival

William Yaxley : the arrival Catalogue of an exhibition held at the University of Tasmania Plimsoll Gallery Centre for the Arts 30 March - 29 April, 1990"--Includes bibliographical references

Communication and Jamming BDA of OFDMA communication systems using the software defined radio platform WARP

The aim of this research is to demonstrate and evaluate the ability to eavesdrop and interfere with orthogonal frequency division multiple access-down link (OFDMA-DL) signal features utilising Wireless Open Access Research Platform (WARP) boards. The OFDMA-DL waveforms have been developed with 64 sub carriers and have guards and pilots as comparable to the 802.11a WiFi standard. An eavesdropper/interferer (ExJx) is used to estimate signal features, remotely gaining intelligence without alerting the communication system. This research also demonstrates how estimated signal features can be used to interfere with an established communication system. Methods used to perform the signal feature estimation exploit the cyclostationary nature of the OFDMA-DL waveform, with higher order cumulants utilised to classify modulation schemes. To assess the ability of the ExJx system to eavesdrop (Ex), Communication Battle Damage Assessment (CBDA) techniques are used. To assess the ability of the ExJx system to interfere (Jx), Jamming Battle Damage Assessment (JBDA) techniques are used

Reconstructing the ancestral phenotypes of great apes and humans (Homininae) using subspecies-level phylogenies

Abstract Owing to their close affinity, the African great apes are of interest in the study of human evolution. Although numerous researchers have described the ancestors we share with these species with reference to extant great apes, few have done so with phylogenetic comparative methods. One obstacle to the application of these techniques is the within-species phenotypic variation found in this group. Here, we leverage this variation, modelling common ancestors using ancestral state reconstructions (ASRs) with reference to subspecies-level trait data. A subspecies-level phylogeny of the African great apes and humans was estimated from full-genome mitochondrial DNA sequences and used to implement ASRs for 14 continuous traits known to vary between great ape subspecies. Although the inclusion of within-species phenotypic variation increased the phylogenetic signal for our traits and improved the performance of our ASRs, whether this was done through the inclusion of subspecies phylogeny or through the use of existing methods made little difference. Our ASRs corroborate previous findings that the last common ancestor of humans, chimpanzees and bonobos was a chimp-like animal, but also suggest that the last common ancestor of humans, chimpanzees, bonobos and gorillas was an animal unlike any extant African great ape.</jats:p

Study of the complete genome sequence of Streptomyces scabies (or scabiei) 87.22

A study of the complete genome sequence of Streptomyces scabies 87.22, a common causative agent of scab disease of tubers including potato (Solanum tuberosum), is described. This work includes annotation of the genome and in-depth description of gene clusters likely to encode biosynthetic pathways for complex natural products and not also found in either “Streptomyces coelicolor” A3(2) or Streptomyces avermitilis MA-4680. Twenty-eight gene clusters were identified as likely to encode enzymes for the biosynthesis of complex natural products. Substances predicted by this work, not previously known to be made by S. scabies 87.22, were confirmed by collaborators as products - desferrioxamines, germicidins, and hopene. Of the clusters identified, fourteen gene clusters are not conserved in the other two streptomycete genome sequences for which comparisons have been undertaken. The Streptomyces genus is a reservoir of producer organisms from which many complex natural products of therapeutic importance have been isolated. These findings suggest that the cargo of cryptic and silent gene clusters amongst other members of this genus may add significantly to previous estimates of undiscovered bioactive natural products. Methods developed in this work could enable other researchers to rapidly identify gene clusters likely to encode enzymes involved in biosynthesis of complex natural products from complete genome sequences. De-replication is a problem for approaches to drug discovery based on activity screening and isolation of wild producer organisms. Computational methods in this work allow rapid de-replication of gene clusters following sequencing which may lead to discovery of many new natural products with therapeutic benefit. Sequences predicted to be involved in scab disease pathogenicity are not found in only one ‘pathogenicity island’ location as expected, but at several loci. Two possible mechanisms were identified from sequence data which it is suggested could be involved in regulation of pathogenicity traits: an MbtH-like protein family and an iron box sequence likely to be triggered response to low iron conditions

Identifying Malnutrition in an Elderly Ambulatory Rehabilitation Population: Agreement between Mini Nutritional Assessment and Validated Screening Tools

Malnutrition is common in older adults and often goes unrecognised and untreated. Australian evidence-based guidelines for the management of malnutrition indicate that only the Mini Nutritional Assessment short form (MNA-sf) and Rapid Screen are recommended for use as malnutrition screening tools in the rehabilitation setting. The aim of this secondary analysis was to assess the validity and reliability of two malnutrition screening tools, validated in other adult sub-groups, in a rehabilitation population aged ≥60 years. The Council on Nutrition Appetite Questionnaire (CNAQ) and the Simplified Nutritional Appetite Questionnaire (SNAQ), were completed by 185 ambulatory rehabilitation patients (48% male; median age 78 years) and results compared to the full MNA as a reference technique. Prevalence of risk of malnutrition was 63% according to the MNA. For identification of risk of malnutrition the CNAQ had sensitivity of 54%, specificity 81%, positive predictive value 83% and negative predictive value 51%, compared to 28%, 94%, 89% and 44%, respectively, using SNAQ. Assessment of reliability indicated significant slight to fair agreement between MNA with CNAQ (κ = 0.309, p < 0.001) and SNAQ (κ = 0.176, p < 0.001). Neither the CNAQ nor the SNAQ have a high level of validity or reliability in this elderly population and are therefore not recommended for use in the ambulatory rehabilitation setting. Further work is necessary to assess the validity and reliability of other malnutrition screening tools to establish their usefulness in this populatio