Barber\u27s pole worm : a new solution

Barber\u27s pole worm (Haemonchus contortus) has been a major problem to the sheep industry for many years. About ten million sheep graze in Western Australia\u27s high rainfall areas where barber\u27s pole worm is prevalent, and the annual cost of losses and control totals millions of dollars each year. Research in progress in Albany now offers the prospect of prolomged and reliable control of barber\u27s pole worm, by means of few drench treatments

The bush tick

A newly discovered livestock parasite has focused attention on farms in the Walpole district in the south-west of Western Australia. Ticks submitted to the Department of Agriculture in December 983 were identified as the bush tick, Haemaphysalis longicornis. An intensive campaign to locate areas of infestation and to limit spread was started in January 1984. The bush tick is a pest of livestock in some areas of New South Wales and Queensland. It is important in a narrow coastal strip from Sydney to Brisbane where total summer rainfall can exceed 1000 mm. In this area heavy tick infestation causes anaemia and ill thrift in cattle. Occasionally, massive numbers of ticks, from 10,000 to 20,000 per beast, may cause death. Fortunately the bush tick does not carry tick fever or any other stock disease. However, in areas with drier summers such as the south-west of Western Australia, the tick is rarely found in large numbers and control measures are seldom necessary. Before a decision is taken to limit or contain the tick\u27s spreadin this State, information is needed on: How far has the tick spread? How far it is likely to spread? How important it is likely to be in Western Australia? How can it be controlle

Farmers\u27 estimations of sheep weights to calculate drench dose

Undersosing with drenches is a mojor cause of anthelmintic (drench) resistance in worm parasites of sheep. When farmers use a drench at less than the recommended dose rate, some worms may survive, and their ability to resist treatment with the chemical involved is passed to their offspring. Over a period of time, matings between worms with different degrees of resistance can produce individuals able to resist the drench at the recommended dose rate or even higher. Farmers must use adequate dose rates so that worms do not have a chance to survive treatment

Understanding Robustness and Generalization of Artificial Neural Networks Through Fourier Masks

Despite the enormous success of artificial neural networks (ANNs) in many disciplines, the characterization of their computations and the origin of key properties such as generalization and robustness remain open questions. Recent literature suggests that robust networks with good generalization properties tend to be biased toward processing low frequencies in images. To explore the frequency bias hypothesis further, we develop an algorithm that allows us to learn modulatory masks highlighting the essential input frequencies needed for preserving a trained network's performance. We achieve this by imposing invariance in the loss with respect to such modulations in the input frequencies. We first use our method to test the low-frequency preference hypothesis of adversarially trained or data-augmented networks. Our results suggest that adversarially robust networks indeed exhibit a low-frequency bias but we find this bias is also dependent on directions in frequency space. However, this is not necessarily true for other types of data augmentation. Our results also indicate that the essential frequencies in question are effectively the ones used to achieve generalization in the first place. Surprisingly, images seen through these modulatory masks are not recognizable and resemble texture-like patterns

The integration of grazing management and anthelmintic treatment to provide clean lambing paddocks in the northern tablelands region of NSW, Australia

The three experiments described in this thesis have been submitted as research articles to Veterinary Parasitology. Each research article has been included in the thesis as an experimental chapter, essentially as submitted for publication but with the abstract removed

Genomic insights into the rapid emergence and evolution of MDR in Staphylococcus pseudintermedius.

OBJECTIVES: MDR methicillin-resistant Staphylococcus pseudintermedius (MRSP) strains have emerged rapidly as major canine pathogens and present serious treatment issues and concerns to public health due to their, albeit low, zoonotic potential. A further understanding of the genetics of resistance arising from a broadly susceptible background of S. pseudintermedius is needed. METHODS: We sequenced the genomes of 12 S. pseudintermedius isolates of varied STs and resistance phenotypes. RESULTS: Nine distinct clonal lineages had acquired either staphylococcal cassette chromosome (SCC) mec elements and/or Tn5405-like elements carrying up to five resistance genes [aphA3, sat, aadE, erm(B), dfrG] to generate MRSP, MDR methicillin-susceptible S. pseudintermedius and MDR MRSP populations. The most successful and clinically problematic MDR MRSP clones, ST68 SCCmecV(T) and ST71 SCCmecII-III, have further accumulated mutations in gyrA and grlA conferring resistance to fluoroquinolones. The carriage of additional mobile genetic elements (MGEs) was highly variable, suggesting that horizontal gene transfer is frequent in S. pseudintermedius populations. CONCLUSIONS: Importantly, the data suggest that MDR MRSP evolved rapidly by the acquisition of a very limited number of MGEs and mutations, and that the use of many classes of antimicrobials may co-select for the spread and emergence of MDR and XDR strains. Antimicrobial stewardship will need to be comprehensive, encompassing human medicine and veterinary disciplines to successfully preserve antimicrobial efficacy

Wearable Haptic Devices for Gait Re-education by Rhythmic Haptic Cueing

This research explores the development and evaluation of wearable haptic devices for gait sensing and rhythmic haptic cueing in the context of gait re-education for people with neurological and neurodegenerative conditions. Many people with long-term neurological and neurodegenerative conditions such as Stroke, Brain Injury, Multiple Sclerosis or Parkinson’s disease suffer from impaired walking gait pattern. Gait improvement can lead to better fluidity in walking, improved health outcomes, greater independence, and enhanced quality of life. Existing lab-based studies with wearable devices have shown that rhythmic haptic cueing can cause immediate improvements to gait features such as temporal symmetry, stride length, and walking speed. However, current wearable systems are unsuitable for self-managed use for in-the-wild applications with people having such conditions. This work aims to investigate the research question of how wearable haptic devices can help in long-term gait re-education using rhythmic haptic cueing. A longitudinal pilot study has been conducted with a brain trauma survivor, providing rhythmic haptic cueing using a wearable haptic device as a therapeutic intervention for a two-week period. Preliminary results comparing pre and post-intervention gait measurements have shown improvements in walking speed, temporal asymmetry, and stride length. The pilot study has raised an array of issues that require further study. This work aims to develop and evaluate prototype systems through an iterative design process to make possible the self-managed use of such devices in-the-wild. These systems will directly provide therapeutic intervention for gait re-education, offer enhanced information for therapists, remotely monitor dosage adherence and inform treatment and prognoses over the long-term. This research will evaluate the use of technology from the perspective of multiple stakeholders, including clinicians, carers and patients. This work has the potential to impact clinical practice nationwide and worldwide in neuro-physiotherapy

A survey of drench resistance in sheep worms

Sheep worms which are resistant to chemical drenches have been detected with increasing freuency is Western Australia\u27s south-western farming areas between 977 and 1980. These worms have anthelmintic resistance and such genetis resistance puts essential internal parasite control practices at risk. This prompted veterinarians in the Esperance, Albany, Bunbury, Geraldton and Northam areas to survey farms to determine the prevalence of resistance to drenches and to define those sheep management practices which encourage its development. This article describes the survey which was conducted to assess the extent of drench resistance, what causes its build-up and how it can be controlled by using a combination of drenching programme changes and sheep management practices. It has been estimated that drench resistance alone could cost the State\u27s sheep industry $4 million to$6 million a year in lost production, and, as shis survey shows, there is potential for far greater costs if resistance continues to increase

Differences in efficacy of monepantel, derquantel and abamectin against multi-resistant nematodes of sheep

Drug resistance has become a global phenomenon in gastrointestinal nematodes of sheep, particularly resistance to macrocyclic lactones. New anthelmintics are urgently needed for both the control of infections with multi-resistant nematodes in areas where classical anthelmintics are no longer effective, and the prevention of the spread of resistance in areas where the problem is not as severe. Recently, two new active ingredients became commercially available for the treatment of nematode infections in sheep, monepantel (Zolvix®) and derquantel, the latter used only in a formulated combination with the macrocyclic lactone, abamectin (Startect®). In order to assess the potential of the new actives for the control and prevention of spread of anthelmintic resistance, two characterized multi-resistant field isolates from Australia were used in a GLP (good laboratory practice) conducted efficacy study in sheep. Eight infected sheep in each group were treated orally according to the product labels with 2.5 mg/kg body weight monepantel, 0.2 mg/kg abamectin, or with the combination of 2.0 mg/kg derquantel and 0.2 mg/kg abamectin. The results demonstrate that monepantel was fully effective against multi-resistant species, Trichostrongylus colubriformis and Haemonchus contortus (99.9%). In contrast, the combination of derquantel and abamectin was effective against T. colubriformis (99.9%), but was not effective against larval stages of the barber's pole worm H. contortus (18.3%)