4,064 research outputs found
Dynamics of zz spin correlations in the square-lattice spin-1/2 isotropic XY model
Using the Jordan-Wigner fermionization in two dimensions we obtain the zz
wave vector- and frequency-dependent structure factor for the spin-1/2
isotropic XY model on a spatially anisotropic square lattice. We use the
obtained results to discuss a role of the interchain interaction for the
dynamic properties of quasi-one-dimensional systems.Comment: 9 pages, latex, 3 figure
Immune-mediated haemolytic anaemia secondary to haemotrophic mycoplasma infection in a pet ewe
No abstract available
Performance of the psoroptes ovis - antibody enzyme-linked immunosorbent assay in the face of low-level mite infestation
Psoroptes ovis mites, the causative agent of sheep scab, can severely compromise sheep welfare and production. However, in subclinical infections, mite detection is difficult increasing the risk of spread. A recent serodiagnostic test, based on detecting host antibodies to the P ovis allergen, Pso o 2, has made the detection of subclinical infection possible. The use of this test was demonstrated in subclinical situations, through an opportunistic observational study on an extensive hill farm and a lowland flock with recently introduced, quarantined livestock. Twelve animals were tested from each group. Breeding ewes and lambs on the hill farm had seroprevalences of 16 per cent (12.5–17.8 per cent) and 8.3 per cent (4.8–10.1 per cent), respectively. Quarantined store lambs had a seroprevalence of 16.7 per cent (13.2–18.5 per cent); no evidence of P ovis was found in quarantined replacement ewes. By detecting subclinical infection, this serological test could be a powerful tool in sheep scab control, for quarantine procedures, accreditation programmes, and possibly regional or national eradication protocols
Effect of cobalt supplementation on lamb growth rates in the face of cobalt deficiency
A hill farm in eastern Scotland had noted poor lamb growth rates since 2014. Cobalt, selenium and copper deficiencies were reported from historical blood sample results, and trace element supplementation had been administered to the ewes, but not the lambs. A supplementation trial was undertaken in 2018 to compare the daily liveweight gain (DLWG) between lambs supplemented with trace elements and unsupplemented lambs. The trace element supplements used were intraruminal boluses containing 51-mg cobalt, 10-mg selenium and 60-mg iodine (Downland Essential Lamb bolus, Downland). Blood samples taken two months postsupplementation showed that unsupplemented lambs had cobalt-deficient status, but not selenium deficiency. Lambs supplemented with the trace element boluses had an increase in DLWG of 49 g/day compared with unsupplemented lambs. This case confirms that cobalt supplementation on deficient farms can be associated with a significant improvement in growth rates of growing lambs on Scottish hill farms
Taking up physical activity in later life and healthy ageing: the English longitudinal study of ageing
Background Physical activity is associated with improved overall health in those people who survive to older ages, otherwise conceptualised as healthy ageing. Previous studies have examined the effects of mid-life
physical activity on healthy ageing, but not the effects of taking up activity later in life. We examined the association between physical activity and healthy ageing
over 8 years of follow-up.
Methods Participants were 3454 initially disease-free men and women (aged 63.7±8.9 years at baseline) from the English Longitudinal Study of Ageing, a prospective
study of community dwelling older adults. Self-reported physical activity was assessed at baseline (2002–2003) and through follow-up. Healthy ageing, assessed at
8 years of follow-up (2010-2011), was defined as those participants who survived without developing major chronic disease, depressive symptoms, physical or cognitive impairment.
Results At follow-up, 19.3% of the sample was
defined as healthy ageing. In comparison with inactive participants, moderate (OR, 2.67, 95% CI 1.95 to 3.64), or vigorous activity (3.53, 2.54 to 4.89) at least once a
week was associated with healthy ageing, after adjustment for age, sex, smoking, alcohol, marital status and wealth. Becoming active (multivariate adjusted, 3.37, 1.67 to 6.78) or remaining active (7.68, 4.18 to
14.09) was associated with healthy ageing in
comparison with remaining inactive over follow-up.
Conclusions Sustained physical activity in older age is associated with improved overall health. Significant health benefits were even seen among participants who became physically active relatively late in life
Multigeneric resistance to monepantel on a UK sheep farm
The amino acetonitrile derivative, monepantel, represented the first new broad spectrum anthelmintic to be brought to market for use in sheep for over 25 years when it was introduced in 2009. This study characterised monepantel efficacy, using faecal egg count reduction and controlled efficacy tests, against gastrointestinal nematodes following a report of treatment failure in a UK lowland sheep flock. Twelve lambs were each artificially administered 15,000 infective larvae that had been propagated from lamb faeces collected from the farm of interest. The controlled efficacy test showed that a recommended dose rate of monepantel (2.5 mg/kg body weight) administered at day 28 post infection was ineffective at removing the infection in the treated lambs. The result demonstrated simultaneous resistance to monepantel in Teladorsagia circumcincta, Trichostrongylus vitrinus and Oesophagostomum venulosum with efficacies based on adult worm burden reductions, compared to untreated controls, of 78%, 27% and 22% respectively. Monepantel efficacy based on undifferentiated egg count in treated animals, seven day post administration, compared to untreated controls was 85%. The results raise questions about the origins of, and predisposing factors for, resistance development in the three different species, and reinforces the value of differentiating post treatment faecal egg counts to genus or species level
Case report: failure of passive transfer and neonatal infections in a cohort of lambs
This case report details an outbreak of neonatal lamb deaths, in which 84 of the 1203 potential lambs (from scanning) died and 70 developed septic polyarthritis. Investigation of the Scottish lowland flock of 650 breeding ewes revealed good lambing-time hygiene; poor ewe nutrition was suspected to have led to poor colostrum quality or quantity, resulting in failure of passive transfer of immunity in lambs. Ewe body condition at lambing was poor, with low blood urea nitrogen and albumin levels in pre-lambing ewe metabolic blood profiles
Use of ultrasonographic examination in sheep veterinary practice
This review describes the current, emerging and potential applications of ultrasonography in the field of first-opinion sheep veterinary practice. The most widespread application is pregnancy diagnosis, where both transrectal and transabdominal ultrasonography offer a highly sensitive tool for, among others, detection of pregnancy, identification of foetal number and diagnosis of uterine abnormalities, e.g., metritis. The diagnostic applications of ultrasonography for imaging the lungs, heart, male genitourinary system and superficial swellings are also described. Through review of recent research in sheep and by analogy from applications in other animal species, the potential role of ultrasonography in screening programmes for cystic echinococcosis or ovine pulmonary adenocarcinoma, diagnosis of ocular and laryngeal disease and localisation of Coenurus cysts is explored
Ground state parameters, finite-size scaling, and low-temperature properties of the two-dimensional S=1/2 XY model
We present high-precision quantum Monte Carlo results for the S=1/2 XY model
on a two-dimensional square lattice, in the ground state as well as at finite
temperature. The energy, the spin stiffness, the magnetization, and the
susceptibility are calculated and extrapolated to the thermodynamic limit. For
the ground state, we test a variety of finite-size scaling predictions of
effective Lagrangian theory and find good agreement and consistency between the
finite-size corrections for different quantities. The low-temperature behavior
of the susceptibility and the internal energy is also in good agreement with
theoretical predictions.Comment: 6 pages, 8 figure
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