345 research outputs found
The sheep lice detection test
Sheep farmers would agree it is difficult to find sheep lice when carrying out an inspection.
The lice detection test makes this task easier and helps farmers decide how to control lice. The test also helps community liaison groups with eradication of lice infestations in specific areas, and provides data for epidemiologists to monitor changes in prevalence of lice and efficacy of treatments. Tests are much cheaper than flock inspection on the farm.
The present lice detection test was developed by the Australian Wool Testing Authority (A WTA) and introduced as an integral part of the Western Australian Sheep Lice Eradication Campaign in 1987. In Western Australia, more than 82,000 lots of wool submitted under 11,400 wool bale brands are tested each year. More than 80 per cent of these brands have been identified to wool growers.
Presently, each Western Australian wool grower contributes about $45 a year towards the cost of conducting 82, 000 tests. Expressed another way, it costs about 1.5 cents per head to test for lice in sheep
Western Australia - A Johne\u27s disease free zone
The control of Johne\u27s disease (JD) in Australia is coordinated nationally by Animal Health Australia in conjunction with the livestock industries and the Commonwealth and State Governments. Zones were established for Australia in July 1999 to control the spread of JD. These zones ensured that surveillance established the prevalence of JD, and that movement restrictions on livestock appropriate to the zone status were implemented. Following many years of surveillance and restrictions on the introduction of livestock, Western Australia has now been declared a Johne\u27s Disease Free Zone - the first in Australia. Johne\u27s Disease State Coordinator Peter Morcombe looks at the disease, and details how Agriculture Western Australia has worked with livestock owners and importers to meet the criteria set for declaration as a Free Zone
The incidence of lupinosis in sheep grazing Phomopsis-resistant lupin stubbles
Lupinosis is one of the major diseases of grazing livestock in Western Australia. It occurs when animals graze lupin stubble containing toxins produced by the fungus Phomopsis leptostromiformis. The Department of Agriculture has recently released new cultivars of Lupinus angustifolius which are more resistant to colonization by Phomopsis, and therefore develop less toxicity, than those previously available (Cowling et al. 1988). The new cultivars - Gungurru and Yorrel - are called Phomopsis-resistant, however their resistance is only moderate. The old cultivars are referred to as Phomopsis-susceptible
Influence of body mass index and gender on physical activity in primary school children during PE and non-PE school days
The benefits of physical activity (PA) for children are well recognised. Children who display high levels of moderate to vigorous physical activity (MVPA) have a lower risk of becoming overweight/obese(1) or becoming inactive adults(2). Existing evidence suggests a potential interaction between gender and BMI in terms of PA, with low MVPA associated with those with greater BMI z-scores in 7–9 year old girls, but not boys(3). In 2014, the new National Curriculum for England was implemented across the UK for Physical Education (PE). The aim of this study was to compare objectively measured PA on PE and non-PE days and determine whether children’s BMI and gender influenced the differences found.
PA was measured using tri-axial accelerometers (Actigraph GT3X-BT) worn at the hip in male (n 47) and female (n 39) children aged 6·8 (SD 0·6) years, height 123·2 (SD 5·6) cm and body mass 24·45 (SD 3·95) kg over four days at school (360 min per day). The duration of sedentary and MVPA in regular class time and structured PE classes (46 (SD 12) min duration) was measured using the previously validated Pulsford cut off points(4). BMI z-scores were calculated using WHO guidelines. Data were analysed using Pearson correlations, paired samples and independent samples t-tests, Cohen’s d for effect sizes (ES) and are presented as mean (SD).
Children carried out more MVPA on PE days compared to non-PE days (ES = 0·78) and during PE lessons compared to corresponding non-PE time. Furthermore, children were significantly less sedentary in PE lessons compared to corresponding non-PE time. Consequently, children spent less overall time in the sedentary activity category on PE days compared to non-PE days(ES = 0·68). Childrens’ BMI z-scores correlated significantly with their quantity of sedentary and light activity (P < 0·001), but not MVPA (P = 0·60) and were very similar on both PE and non-PE days. Males were more active than their female peers, performing 8 and 6 min more MVPA (ES 0·89, 0·72) and 12 and 8 min less sedentary time on PE and non-PE days (ES −0·62, −0·42), respectively.
In conclusion, PE lessons increased childrens’ daily MVPA and reduced their sedentary time. Although gender and BMI were associated with PA levels, the inclusion of PE lessons did not markedly increase their influence on overall energy expenditure. Overall, the study shows that PE lessons have a positive effect on childrens’ PA levels, likely resulting in positive effects on adiposity and overall health and wellbeing.
1. Bornstein D, Beets M, Byun W et al. (2011) J Sci Med Sport 14, 504–511.
2. Biddle SJH, Pearson N, Ross GM et al. (2010) Prev Med 51, 345–51.
3. Basterfield L, Adamson AJ, Pearce MS et al. (2011) J Phys Act Health 8, 543–547.
4. Pulsford RM, Cortina-Borja M, Rich C et al. (2011) PLoS One 6, 1–9
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 6 million a year in lost production, and, as shis survey shows, there is potential for far greater costs if resistance continues to increase
Site-specific perturbations of alpha-synuclein fibril structure by the Parkinson's disease associated mutations A53T and E46K.
PMCID: PMC3591419This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Parkinson's disease (PD) is pathologically characterized by the presence of Lewy bodies (LBs) in dopaminergic neurons of the substantia nigra. These intracellular inclusions are largely composed of misfolded α-synuclein (AS), a neuronal protein that is abundant in the vertebrate brain. Point mutations in AS are associated with rare, early-onset forms of PD, although aggregation of the wild-type (WT) protein is observed in the more common sporadic forms of the disease. Here, we employed multidimensional solid-state NMR experiments to assess A53T and E46K mutant fibrils, in comparison to our recent description of WT AS fibrils. We made de novo chemical shift assignments for the mutants, and used these chemical shifts to empirically determine secondary structures. We observe significant perturbations in secondary structure throughout the fibril core for the E46K fibril, while the A53T fibril exhibits more localized perturbations near the mutation site. Overall, these results demonstrate that the secondary structure of A53T has some small differences from the WT and the secondary structure of E46K has significant differences, which may alter the overall structural arrangement of the fibrils
An Amyloid Organelle: Solid State NMR Evidence for Cross-Beta Assembly of Gas Vesicles
Functional amyloids have been identified in a wide range of organisms, taking on a variety of biological roles and being controlled by remarkable mechanisms of directed assembly. Here, we report that amyloid fibrils constitute the ribs of the buoyancy organelles of Anabaena flos-aquae. The walls of these gas-filled vesicles are known to comprise a single protein, GvpA, arranged in a low pitch helix. However, the tertiary and quaternary structures have been elusive. Using solid-state NMR correlation spectroscopy we find detailed evidence for an extended cross-β structure. This amyloid assembly helps to account for the strength and amphiphilic properties of the vesicle wall. Buoyancy organelles thus dramatically extend the scope of known functional amyloids.National Institutes of Health (U.S.) (grant EB001035)National Institutes of Health (U.S.) (grant EB003151)National Institutes of Health (U.S.) (grant EB002026
Solid-state NMR evidence for inequivalent GvpA subunits in gas vesicles
Gas vesicles are organelles that provide buoyancy to the aquatic microorganisms that harbor them. The gas vesicle shell consists almost exclusively of the hydrophobic 70-residue gas vesicle protein A, arranged in an ordered array. Solid-state NMR spectra of intact collapsed gas vesicles from the cyanobacterium Anabaena flos-aquae show duplication of certain gas vesicle protein A resonances, indicating that specific sites experience at least two different local environments. Interpretation of these results in terms of an asymmetric dimer repeat unit can reconcile otherwise conflicting features of the primary, secondary, tertiary, and quaternary structures of the gas vesicle protein. In particular, the asymmetric dimer can explain how the hydrogen bonds in the β-sheet portion of the molecule can be oriented optimally for strength while promoting stabilizing aromatic and electrostatic side-chain interactions among highly conserved residues and creating a large hydrophobic surface suitable for preventing water condensation inside the vesicle.National Institutes of Health (U.S.) (Grant EB002175)National Institutes of Health (U.S.) (Grant EB003151)National Institutes of Health (U.S.) (Grant EB002026
The use of variable temperature 13 C solid-state MAS NMR and GIPAW DFT calculations to explore the dynamics of diethylcarbamazine citrate
Experimental 13C solid‐state magic‐angle spinning (MAS) NMR as well as DFT (gauge‐including projector augmented wave) GIPAW calculations were used to probe disorder and local mobility in diethylcarbamazine citrate, (DEC)+(citrate)‐. This compound has been used as the first option drug for the treatment of filariasis, a disease endemic in tropical countries and caused by adult worms of Wuchereria bancrofti, which is transmitted by mosquitoes. We firstly present 2D 13C‐1H dipolar‐coupling mediated heteronuclear correlation spectra recorded at moderate spinning frequency, to explore the intermolecular interaction between DEC and citrate molecules. Secondly, we investigate the dynamic behaviour of (DEC)+(citrate)‐ by varying the temperature and correlating the experimental MAS NMR results with DFT GIPAW calculations that consider two (DEC)+ conformers (in a 70:30 ratio) for crystal structures determined at 293 and 235 K. Solid‐state NMR provides insights on slow exchange dynamics revealing conformational changes involving particularly the diethylcarbamazine ethyl groups
Organic matter chemistry controls greenhouse gas emissions from permafrost peatlands
Large tracts of arctic and subarctic peatlands are underlain by permafrost. These peatlands store large quantities of carbon (C), and are currently under severe threat from climate change. The aim of this study was to determine the size and organic chemistry of the easily degradable C pool in permafrost peatlands and link the functional organic chemistry to temperature and moisture controls of greenhouse gas emissions. First, we used a combination of field measurements and laboratory experiments to assess the influence of increased temperature and flooding on CO₂ and CH₄ emissions from sixteen permafrost peatlands in subarctic Sweden and Canada. Second, we determined the variation in organic matter chemistry and the associated microbial community composition of the peat active layer, with depth using quantitative ¹³C solid-state NMR and molecular biomarkers respectively. We demonstrate that the peat organic chemistry strongly controls CO₂ release from peat and that ca. 35 and 26% of the peat organic matter, at the Swedish and Canadian peatlands sites, respectively, is easily degradable by heterotrophic microorganisms. In contrast to CO₂, CH₄ emissions were decoupled from peat functional organic chemistry. We show a strong relationship between the microbial community structure and the peat organic chemistry suggesting that substrate type and abundance is an important driver of microbial composition in sub-arctic peatlands. Despite considerable variation in peat chemistry and microbial community composition with depth the temperature sensitivity was comparable throughout the active layer. Our study shows that functional organic chemistry controls both soil respiration rates and the composition of the microbial community. Furthermore, if these peatlands collapse and flood on thawing, they are unlikely to become large emitters of CH₄ without additional input of labile substrates
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