4,558 research outputs found
Epidemiology of bovine ephemeral fever in Australia 1981-1985
Bovine ephemeral fever is an important viral disease of cattle in Australia. The disease occurred each year, principally in summer and autumn, between 1981 and 1985. Queensland and the northern half of New South Wales were areas of greatest activity with only sporadic cases being reported from the Northern Territory and the northern third of Western Australia. Since 1981, the disease has been endemic in an extensive area of eastern Australia and has tended to occur in widely scattered outbreaks rather than the north-south advancing wave form of the epidemics of 1936-37, 1967-68, 1970-71 and 1972-74. The southernmost outbreaks between 1981 and 1985 were well within the limits of these earlier epidemics. The pattern of disease appears to have become seasonally endemic rather than periodically endemic in the northern two-thirds of eastern Australia. Ephemeral fever was not recorded in Victoria, Tasmania, South Australia or the southern part of Western Australia between 1981 and 1985. The disease was most frequently reported in cattle under 3 years of age, but also occurred in older cattle
Direct radiocarbon dating of fish otoliths from mulloway (Argyrosomus japonicus) and black bream (Acanthopagrus butcheri) from Long Point, Coorong, South Australia
Accelerator Mass Spectrometry (AMS) radiocarbon dates (n=20) determined on fish otoliths from mulloway (Argyrosomus japonicus) and black bream (Acanthopagrus butcheri) are reported from five sites at Long Point, Coorong, South Australia. The dates range from 2938–2529 to 326–1 cal. BP, extending the known period of occupation of Long Point. Previous dating at the sites indicated intensive occupation of the area from 2455–2134 cal. BP. Results provide a detailed local chronology for the region, contributing to a more comprehensive understanding of Aboriginal use of Ngarrindjeri lands and waters. This study validates the use of fish otoliths for radiocarbon dating and reveals how dating different materials can result in different midden chronologies
Concepts and Principles of Photodynamic Therapy as an Alternative Antifungal Discovery Platform
Opportunistic fungal pathogens may cause superficial or serious invasive infections, especially in immunocompromised and debilitated patients. Invasive mycoses represent an exponentially growing threat for human health due to a combination of slow diagnosis and the existence of relatively few classes of available and effective antifungal drugs. Therefore systemic fungal infections result in high attributable mortality. There is an urgent need to pursue and deploy novel and effective alternative antifungal countermeasures. Photodynamic therapy (PDT) was established as a successful modality for malignancies and age-related macular degeneration but photodynamic inactivation has only recently been intensively investigated as an alternative antimicrobial discovery and development platform. The concept of photodynamic inactivation requires microbial exposure to either exogenous or endogenous photosensitizer molecules, followed by visible light energy, typically wavelengths in the red/near infrared region that cause the excitation of the photosensitizers resulting in the production of singlet oxygen and other reactive oxygen species that react with intracellular components, and consequently produce cell inactivation and death. Antifungal PDT is an area of increasing interest, as research is advancing (i) to identify the photochemical and photophysical mechanisms involved in photoinactivation; (ii) to develop potent and clinically compatible photosensitizers; (iii) to understand how photoinactivation is affected by key microbial phenotypic elements multidrug resistance and efflux, virulence and pathogenesis determinants, and formation of biofilms; (iv) to explore novel photosensitizer delivery platforms; and (v) to identify photoinactivation applications beyond the clinical setting such as environmental disinfectants
Developing Sustainable Livestock Systems through Participatory Farmer Research
Application Understanding muscular adaptations could inform objective lameness-detection for early diagnosis/treatment,
ultimately serving to detect sub-clinical issues in supposed healthy horses and to reduce pain/ incapacity in lame horses.
Introduction The prevalence and impact of lameness on equine welfare has led to extensive research, which has
biomechanically analysed lameness-related alterations in movement. Despite this, limited information is available about
adaptive muscle activity that facilitates movement during lameness. Surface electromyography (sEMG) is a non-invasive
method for quantifying muscle activity. However, no equine studies have employed sEMG to compare inherent and
adaptive activity during non-lame and standardised lameness conditions, respectively. The aim of this preliminary study
was to compare Triceps Brachii (TB) muscle activity in horses before and after induced forelimb (FL) lameness, using
sEMG data.
Material and methods Six clinically non-lame horses (5 mares, 1 stallion, age: 7.0±3.7 years, height: 162.3±4.0 cm, body
mass: 572.7±45.8 kg) were used. sEMG sensors (Delsys Trigno, Delsys Inc.) were attached bilaterally to locations above
TB (long head), that were prepared by removing all hair and cleaning with isopropyl alcohol. Retro-reflective markers were
attached to anatomical landmarks for quantitative lameness evaluation (QHorse, Qualisys AB) and gait event detection.
sEMG (2000 Hz) and 3D kinematic (200 Hz) data were synchronously collected from horses during in-hand trot trials,
conducted on a straight, hard surfaced runway before (baseline) and after FL lameness induction. Baseline data were
initially collected, then temporary, mild FL lameness (2-3/5 AAEP Lameness Scale) was induced using mechanical bolt
pressure, applied to the tip of the frog and monitored by qualified veterinarians (T.S., F.S.B.) using a modified horseshoe
(Merkens and Schamhardt, 1988). Left and right FL lameness induction were randomised. Following data collection, the
bolt/ sole pressure was removed and no horses showed adverse reactions to lameness inductions, or residual lameness. For
stride segmentation, gait events were detected using kinematic data that were low-pass filtered (Butterworth 4th order, 10
Hz cut-off) and analysed in accordance with the methods described by Holt et al. (2017). To quantify lameness, MinDiff
was calculated using poll vertical displacement data, where healthy horses exhibit MinDiff between -6 – 6mm and left and
right FL lameness are exhibited as more positive and negative values, respectively (Rhodin et al., 2016). Raw sEMG
signals were DC-offset removed, high-pass filtered (Butterworth 4th order, 40 Hz cut-off) (St. George et al., 2018), and fullwave
rectified. Integrated EMG (iEMG) and average rectified value (ARV) were calculated using stride duration as
temporal domain. To reduce inter-subject variability, iEMG and ARV from each horse were normalised to the maximum
value observed for each limb (left/ right FL) across all strides from the baseline condition. Data from the “lame” and “nonlame”
limb were grouped, according to the limb where lameness was induced. A 2x2 repeated measures ANOVA was used
to compare muscle activity between limb (lame, non-lame) and condition (baseline, induced FL lameness). Post-hoc
analyses using Bonferroni correction were performed where significant main effects were found.
Results Mean ± sd MinDiff were baseline:-1.8 ± 8.7 mm, left FL lameness induction:-55.3 ± 34.1 mm, right FL lameness:
56.8 ± 17.9 mm. Significant interactions between limb and condition were found for iEMG (p < 0.05, n2=0.74) and ARV (p
< 0.05, n2=0.75). Post hoc analyses of iEMG and ARV data revealed muscle activity was significantly higher in the lame
limb (p < 0.05) and significantly lower in the non-lame limb (p < 0.01) during the induced FL lameness condition.
Conclusion Preliminary findings reveal neuromuscular adaptations in TB during induced FL lameness. Significant
increases in stance duration have been reported during FL lameness (Weishaupt et al., 2006). Therefore, significant
increases in lame limb muscle activity may be due to prolonged stabilisation of the shoulder and elbow joints, as a
compensatory mechanism of gait adaptation to lameness. Further investigations of additional muscles and chronic lameness
cases are required to determine whether sEMG can provide a complimentary tool for objective lameness detection
New horizons in late-onset essential tremor: a pre-cognitive biomarker of dementia?
Essential tremor (ET) is the most common cause of tremor in older adults. However, it is increasingly recognised that 30-50% of ET cases are misdiagnosed. Late-onset ET, when tremor begins after the age of 60, is particularly likely to be misdiagnosed and there is mounting evidence that it may be a distinct clinical entity, perhaps better termed 'ageing-related tremor'. Compared with older adults with early-onset ET, late-onset ET is associated with weak grip strength, cognitive decline, dementia and mortality. This raises questions around whether late-onset ET is a pre-cognitive biomarker of dementia and whether modification of dementia risk factors may be particularly important in this group. On the other hand, it is possible that the clinical manifestations of late-onset ET simply reflect markers of healthy ageing, or frailty, superimposed on typical ET. These issues are important to clarify, especially in the era of specialist neurosurgical treatments for ET being increasingly offered to older adults, and these may not be suitable in people at high risk of cognitive decline. There is a pressing need for clinicians to understand late-onset ET, but this is challenging when there are so few publications specifically focussed on this subject and no specific features to guide prognosis. More rigorous clinical follow-up and precise phenotyping of the clinical manifestations of late-onset ET using accessible computer technologies may help us delineate whether late-onset ET is a separate clinical entity and aid prognostication
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