Baxterization, dynamical systems, and the symmetries of integrability

We resolve the `baxterization' problem with the help of the automorphism group of the Yang-Baxter (resp. star-triangle, tetrahedron, \dots) equations. This infinite group of symmetries is realized as a non-linear (birational) Coxeter group acting on matrices, and exists as such, {\em beyond the narrow context of strict integrability}. It yields among other things an unexpected elliptic parametrization of the non-integrable sixteen-vertex model. It provides us with a class of discrete dynamical systems, and we address some related problems, such as characterizing the complexity of iterations.Comment: 25 pages, Latex file (epsf style). WARNING: Postscript figures are BIG (600kB compressed, 4.3MB uncompressed). If necessary request hardcopy to [email protected] and give your postal mail addres

Prevention and management of osteoporotic fractures by non-physician health professionals: a systematic literature review to inform EULAR points to consider

Objective To perform a systematic literature review (SLR) about the effect of non-pharmacological interventions delivered by non-physician health professionals to prevent and manage osteoporotic fractures. Methods Eight clinical questions based on two criteria guided the SLR: (1) adults >= 50 years at high risk of osteoporotic fracture and (2) interventions delivered by non-physician health professionals to prevent and manage osteoporotic fractures. Interventions focused on diagnostic procedures to identify risk of falling, therapeutic approaches and implementation strategies. Outcomes included fractures, falls, risk of falling and change in bone mineral density. Systematic reviews and randomised controlled trials were preferentially selected. Data were synthesised using a qualitative descriptive approach. Results Of 15 917 records, 43 articles were included. Studies were clinically and methodologically diverse. We identified sufficient evidence that structured exercise, incorporating progressive resistance training delivered to people who had undergone hip fracture surgery, and multicomponent exercise, delivered to people at risk of primary fracture, reduced risk of falling. The effectiveness of multidisciplinary fracture liaison services in reducing refracture rate was confirmed. There was insufficient evidence found to support the effectiveness of nutrients and falls prevention programmes in this patient population. Conclusion Despite study heterogeneity, our SLR showed beneficial effects of some interventions delivered by non-physician health professionals and the positive impact of multidisciplinary team working and patient educational approaches to prevent and manage osteoporotic fractures. These results informed a EULAR taskforce that developed points to consider for non-physician health professionals to prevent and manage osteoporotic fractures.This study was funded by the EULAR. Grant reference HPR 032.info:eu-repo/semantics/publishedVersio

Investigating management strategies of large litters in pigs

Modern hyper-prolific sows often do not have enough teats to feed all of their piglets. The resulting competition for colostrum and milk hampers piglet growth and survival. This is exacerbated by low birth-weights, which are also common in large litters. Three experiments were conducted for this thesis; each investigated a management strategy hypothesised to improve outcomes for piglets from large litters. The first experiment evaluated the use of nurse sows to rear supernumerous piglets (i.e. when there are more piglets than teats). At 1 day old, piglets from large litters either remained with their mother or were moved to a nurse sow who was either 7 or 21 days into lactation. Aspects of piglet (growth, survival and suckling behaviour) and sow (salivary cortisol, back-fat thickness, body lesions, and nursing behaviour) welfare were monitored until weaning. Rearing by a nurse sow did not compromise pre-weaning survival, compared to rearing by the mother, regardless of the nurse sows’ stage of lactation (7 or 21 days) when the piglets were transferred to her. Piglets reared by a nurse sow were initially heavier than piglets remaining with their dam, but all piglets were weaned at similar weights. Regardless of whether a nurse sow or biological mother, sows in late lactation had shorter nursing bouts and their litter showed more fighting behaviour, compared to sows in early lactation. Despite longer lactation length, nurse sows did not differ from biological mothers in salivary cortisol concentration, backfat thickness and body lesion scores. The second experiment looked at using an artificial rearing system to rear 7 day old piglets until weaning. Litters of 12 piglets were assigned at 7 days old to be either sow-reared (SR) or artificially-reared (AR) until weaning. Pre-weaning survival, growth and behaviour were recorded, emotional state was assessed using Qualitative Behavioural Assessment pre- and post-weaning, and reactivity tests were conducted post-weaning. Survival did not differ between treatments. AR piglets were lighter than SR piglets from the day following transfer until weaning. They performed more negative behaviours (belly-nosing, ear and tail biting) and their emotional state was scored lower pre-weaning, compared to SR piglets. However, post-weaning the emotional state of AR piglets was scored higher than SR pigs and AR piglets had a lower emotional reaction to a fear test (startling event) and human contact. The third experiment evaluated whether 2ml of an energy-rich neonatal supplement (coconut oil or a commercial product) would enhance survival and vitality of low birth-weight piglets. At three hours post-birth, low birthweight piglets (<1.1 kg) were dosed with one of the supplements, water, or sham-dosed. Blood glucose content, rectal temperature, and pre-weaning survival and growth were recorded but none were affected by treatment. Post-weaning, piglets were tested for spatial learning and memory in a T-maze set-up, or were tested for short-term memory in a spontaneous object recognition test. There were no treatment differences on the performance of pigs in any of the two tests, meaning that the birth energy supplementation did not enhance post-weaning cognitive performances. This thesis demonstrated that a single dose of energy supplementation at birth did not improve outcomes for low birth-weight piglets, and that the rearing strategies to promote piglet survival in large litters do work in terms of survival but can impair some aspects of piglet welfare and development. The most pronounced welfare impacts were observed with artificial rearing. Therefore management of large litters remains a significant challenge and the strategies investigated deserve further improvements

Factors influencing the use of research for policy-making: An umbrella review protocol

Over the last two decades, there has been an emphasis on the concept of evidence-based policy. However, evidence-based policy remains a major challenge and a gap exists in the systematic translation of scientific knowledge into policies. The awareness of this evidence-policy gap has led to a proliferation of research. As the demand for evidence-informed policy-making escalates, so does the need to unveil the mechanisms by which we can influence the process of research uptake. In this paper, we present a protocol for a systematic review. We aim to conduct an umbrella review/overview of reviews about factors affecting the use of research by policy-makers and/or decision-makers in health, education and social services areas. The results of this review could contribute to improving the utilisation of research in the policy-making process, by identifying factors that are most important in influencing the uptake of research by policy-makers

Seasonal changes in basking shark vertical space-use in the north-east Atlantic

This is the final version. Available on open access from Springer via the DOI in this recordMobile marine species can exhibit vast movements both horizontally and vertically. Spatial analysis of vertical movements may help improve an understanding of the processes that influence space-use. Previously, vertical space-use of basking sharks (Cetorhinus maximus) in the north-east Atlantic described movements largely within waters of the continental shelf during summer and autumn months, with few records of detailed vertical behaviour during winter. We use archival satellite telemetry data from 32 basking sharks (twelve females, six males, and fourteen of unknown sex measuring 4-5 m (n = 6), 5-6 m (n = 10), 6-7 m (n = 7), 7-8 m (n = 8), and 8-9 m (n = 1) estimated total length) tracked over four years (2012-2015). The satellite tags provided depth and temperature data for a cumulative 4,489 days (mean 140 ± 97 days per shark, range: 10-292 days) in order to describe vertical space-use and thermal range of basking sharks in the north-east Atlantic. Basking sharks exhibit seasonality in vertical space-use, revealing repeated ‘yo-yo’ movement behaviour with periods of occupancy at depths greater than 1,000 metres in late winter/early spring. Describing seasonal vertical space-use in marine megavertebrates can increase knowledge of movements throughout their environment including physiological and morphological constraints to movement, nutrient transfer, and overlap with anthropogenic threats in order to inform future conservation strategies.Scottish Natural HeritageUniversity of ExeterNER

Epidemics in partially overlapped multiplex networks

Many real networks exhibit a layered structure in which links in each layer reflect the function of nodes on different environments. These multiple types of links are usually represented by a multiplex network in which each layer has a different topology. In real-world networks, however, not all nodes are present on every layer. To generate a more realistic scenario, we use a generalized multiplex network and assume that only a fraction $q$ of the nodes are shared by the layers. We develop a theoretical framework for a branching process to describe the spread of an epidemic on these partially overlapped multiplex networks. This allows us to obtain the fraction of infected individuals as a function of the effective probability that the disease will be transmitted $T$. We also theoretically determine the dependence of the epidemic threshold on the fraction $q > 0$ of shared nodes in a system composed of two layers. We find that in the limit of $q \to 0$ the threshold is dominated by the layer with the smaller isolated threshold. Although a system of two completely isolated networks is nearly indistinguishable from a system of two networks that share just a few nodes, we find that the presence of these few shared nodes causes the epidemic threshold of the isolated network with the lower propagating capacity to change discontinuously and to acquire the threshold of the other network.Comment: 13 pages, 4 figure