4 research outputs found
Compatibility studies of several molten uranium and thorium alloys in niobium, tantalum, and yttrium
Niobium, tantalum, yttrium, and Inconel have been used to contain molten aluminum, lead, tin, zinc, and several of their respective uranium and thorium alloys for various times up to 3000 hours and at temperatures ranging from 600 to 1100° C. Altogether 76 capsule tests were run, almost all in a static isothermal condition. Tantalum showed the best resistance followed by niobium, Inconel, and yttrium respectively. The systems, lead in tantalum and lead in niobium, showed the greatest potentials for possible liquid-metal fuel carrier systems. An alloy of uranium-bismuth-tin contained in tantalum also exhibited promising possibilities . The tabulated test data include a classification of the type of corrosion attack which occurred and a measured value of the amount of corrosive penetration. Each test was also given an arbitrary rating for easy reference comparisons. A number of photomicrographs are included for each set of tests
Detection of equine herpesvirus-4 and physiological stress patterns in young Thoroughbreds consigned to a South African auction sale
BACKGROUND : The prevalence of equine herpesvirus types-1 and -4 (EHV-1 and -4) in South African Thoroughbreds
at auction sales is currently undefined. Commingling of young Thoroughbreds from various populations together
with physiological stress related to their transport and confinement at a sales complex, may be associated with
shedding and transmission of EHV-1 and -4. This prospective cohort study sampled 90 young Thoroughbreds
consigned from eight farms, originating from three provinces representative of the South African Thoroughbred
breeding demographic to a sales complex. Nasal swabs for quantitative real-time polymerase chain reaction
(qPCR) assay to detect EHV-1 and -4 nucleic acid and blood samples for enzyme-linked immunosorbent assay
for EHV-1 and -4 antibodies were collected from all horses on arrival and departure. Additional nasal swabs for
qPCR were obtained serially from those displaying pyrexia and, or nasal discharge. Daily faecal samples were
used for determination of faecal glucocorticoid metabolite (FGM) concentrations as a measurement of physiological
stress and these values were modelled to determine the factors best explaining FGM variability.
RESULTS : EHV-4 nucleic acid was detected in 14.4 % and EHV-1 from none of the animals in the study population.
Most (93.3 %) and very few (1.1 %) of this population showed antibodies indicating prior exposure to EHV-4 and
EHV-1 respectively. Pyrexia and nasal discharge were poor predictors for detecting EHV-4 nucleic acid. The horsesâ
FGM concentrations increased following arrival before decreasing for most of the remaining study period including the
auction process. Model averaging showed that variation in FGM concentrations was best explained by days post-arrival
and transport duration.
CONCLUSIONS : In this study population, sales consignment was associated with limited detection of EHV-4 nucleic
acid in nasal secretions, with most showing prior exposure to EHV-4 and very few to EHV-1. The physiological stress
response shown by most reflected the combination of stressors associated with transport and arrival and these are
key areas for future investigation into management practices to enhance health and welfare of young Thoroughbreds
during sales consignment.Racing South Africa (Pty) Ltd, the
Equine Research Centre and Departments of Companion Animal Clinical
Studies and Production Animal Clinical Studies, Faculty of Veterinary Science,
University of Pretoria, South Africa.http://www.biomedcentral.com/bmcvetresam201
Fecal Glucocorticoid Metabolites as Biomarkers in Equids: Assay Choice Matters
From Wiley via Jisc Publications RouterHistory: received 2020-05-06, rev-recd 2021-03-29, accepted 2021-04-09, pub-electronic 2021-06-01Article version: VoRPublication status: PublishedFunder: Royal Society; Id: http://dx.doi.org/10.13039/501100000288; Grant(s): UF110641Funder: Chester Zoo; Id: http://dx.doi.org/10.13039/501100005359; Grant(s): Conservation FellowshipABSTRACT: Free ranging animals are exposed to environmental, demographic, and ecological challenges over time, which can affect their health and fitness. Nonâinvasive biomarkers can provide insight into how animals cope with these challenges and assess the effectiveness of conservation management strategies. We evaluated how free ranging ponies (Equus ferus caballus) on the Carneddau Mountain range, North Wales respond to 2 stimuli: an acute stressor of an annual roundup event in November 2014, and spatial and temporal variation in ecological factors in 2018. We evaluated fecal glucocorticoid metabolites using 2 enzyme immunoassays (EIAs): an 11âoxoetiocholanolone EIA (measuring 11,17âdioxoandrostanes [11,17âDOAs]) and a corticosterone EIA. The former assay has been validated in equids, whereas there is limited evidence for the suitability of the latter. We used an additional parent testosterone EIA to measure fecal androgen metabolites in response to the ecological challenges. Following the roundup, the metabolite concentrations measured by the 2 glucocorticoid EIAs were not correlated. The 11,17âDOAs were elevated from the second day following the roundup and then slowly returned to preâround levels over the next 2 weeks. In contrast, the metabolites measured by the corticosterone assay showed no response to the roundup. For the ecological data, all 3 assays detected a positive correlation between metabolites and social group size in males but not in females. The metabolite concentrations measured by the testosterone and corticosterone assays were highly correlated and were temporally associated with the onset of the breeding season, whereas the 11,17âDOAs were not. The coâvariance of metabolites measured by the corticosterone and testosterone assays, and the lack of an acute response in the corticosterone assay to the roundup, suggests that metabolites detected by the corticosterone assay were not primarily associated with increased glucocorticoid production. We recommend using wellâvalidated fecal biomarker assays of hypothalamusâpituitaryâadrenal axis activity to evaluate and compare the effect of different management interventions and environmental change. © 2021 The Authors. The Journal of Wildlife Management published by Wiley Periodicals LLC on behalf of The Wildlife Society