916 research outputs found
Exploring the Impact of a Global Pandemic (COVID-19) on Factors Impacting the Resilience of Top-Tier London Hockey Players
Introduction. The cessation of all professional and amateur sport due to the COVID-19 pandemic had a dramatic effect on the mental and physical capacity of the United Kingdom populace, but its impact was arguably felt more deeply by the athletic population. Thus, this research explored which limiting factors were experienced by team hockey players during the national lockdowns (1.0–3.0) with the objective of enabling coaches and team management to better support and protect players’ physiological and psychological resilience in return to play. Methods. Data were collected over 12 weeks during the 3rd UK lockdown (March 2021) from two top-tier London clubs. Hockey players (n = 63) completed an online questionnaire that included validated tests for self-compassion, sport motivation, and a custom open-ended style qualitative questionnaire on nutrition and lifestyle behaviour. Mean self-compassion, motivation scores, and common indicative limiting factors were evaluated and ranked according to significance. Results. High “rebound resilience” was found with low amotivation scores (m = 8.33) and strong affinity for their sport identifying with the statement “because participation in my sport is an integral part of my life” with correspondingly high integrated regulation scores (m = 21.43). Participants’ self-compassion showed the highest scores in mindfulness (m = 3.66) and lowest in self-kindness (m = 2.84) indicating a common trait in athletes for self-criticism. The highest limiting factor was cited as “no social outlets, social interactions, or seeing friends and family”. Conclusion. This study revealed the critical role that social connectedness plays in promoting resilience and enhancing motivation in return to play during extremely challenging circumstances. When the social outlet is absent, enhancing resilience factors with mindfulness, self-compassion, and the creation of a more facilitative environment where player welfare takes priority are potential strategies to support players when they are unable to participate in their sport
Canine dystocia in 50 UK first-opinion emergency-care veterinary practices: prevalence and risk factors
Dystocia can represent a major welfare issue for dogs of certain breeds and morphologies. First-opinion emergency-care veterinary caseloads represent a useful data resource for epidemiological research because dystocia can often result in emergency veterinary care. The study analysed a merged database of clinical records from 50 first-opinion emergency-care veterinary practices participating in the VetCompass Programme. Multivariable logistic regression modelling was used for risk factors analysis. There were 701 dystocia cases recorded among 18,758 entire female dogs, resulting in a dystocia prevalence of 3.7 per cent (95 per cent CI 3.5–4.0 per cent). Breeds with the highest odds of dystocia compared with crossbred bitches were French Bulldog (OR: 15.9, 95 per cent CI 9.3 to 27.2, P<0.001), Boston Terrier (OR: 12.9, 95 per cent CI 5.6 to 29.3, P<0.001), Chihuahua (OR: 10.4, 95 per cent CI 7.0 to 15.7, P<0.001) and Pug (OR: 11.3, 95 per cent CI 7.1 to 17.9, P<0.001). Bitches aged between 3.0 and 5.9 years had 3.1 (95 per cent CI 2.6 to 3.7, P<0.001) times the odds of dystocia compared with bitches aged under 3.0years. Certain breeds, including some brachycephalic and toy breeds, appeared at high risk of dystocia. Opportunities to improve this situation are discussed
Relationship between microstructure and stable pitting initiation in aerospace aluminium alloy 2024-T3
Aluminium alloys are essential to a variety of industry sectors, particularly transport, where they are used in the production of cars and aeroplanes. However, aluminium alloys are susceptible to degradation through corrosion which can compromise the integrity of components manufactured from this material. Therefore research into the means by which these alloys degrade is important. This thesis aims to understand how one of the more potentially damaging types of corrosion, known as pitting corrosion, occurs in the important aluminium alloy 2024-T3 (AA2024-T3). In order to study this phenomenon, this thesis first characterises the alloy microstructure in detail, particularly the type and distribution of intermetallic particles since these play an important role in corrosion processes. The microstructure was studied using an electron microprobe analysis of a 5 mm x 5 mm area of AA2024-T3 and some 80,000 particles were characterised. This investigation was one of the most comprehensive studies to date of any aluminium alloy. Of the particles studied, it was found that the major types included the S and θ phases and a number of compositions based around AlCuFeMn and AlCuFeMnSi. Depletion zones were an integral feature of the alloy microstructure. Pair correlation functions were used to determine the degree of clustering and it was found that there was both inter particle as well as intra particle clustering. Inter particle clustering was observed at length scales well beyond 50 µm. A detailed study of corrosion on AA2024-T3 was undertaken by examining the surface after corrosion over a time period spanning 2.5 minutes to 120 minutes. From this investigation, a hierarchy of the localised corrosion was observed as it was very apparent that particles of particular elemental compositions were more susceptible to attack much sooner than other compositions. Larger corrosion attack sites on the surface, which were called co-operative corrosion, were attributed to intermetallic clustering affects and changes in chemical composition such as Cu-enrichment. These results were used to develop a detailed model of the initiation of stable pitting corrosion in AA2024-T3, which will lead to a better understanding on how to prevent pitting attack on commercially important aluminium alloys. AA2024-T3 is rarely used in the polished state, for real world applications is it generally finished by mechanical or chemical processing. In the final part of this thesis, the influence of clusters on metal finishing was examined using a standard aluminium chemical deoxidiser. It was found that the etch rate of this deoxidiser increased dramatically with the increase in temperature. Under certain processing conditions only the intermetallic particles are etched out and these retain the history of the spatial distribution of the clustering of the intermetallic particles. This leaves a cluster of 'holes' which could trap metal finishing solution and lead to severe subsurface attac
Natural History of the Peregrine Falcon in the Keewatin District of the Northwest Territories
A dense, productive population of peregrine falcons (Falco peregrinus) was studied for five years on a 450 sq km study area located along the northwest coast of Hudson Bay. The mean internest distance of 3.3 km represents the highest nesting density on record for the species in the Arctic. Morphometric and plumage characteristics of adults in the population suggest they are intermediate between F.p. tundrius from farther north and F.p. anatum from boreal regions to the south and west. The migratory pathway used by this population of birds is similar to that used by peregrines from Alaska, northern Canada, and Greenland. Both timing of arrival on the breeding grounds and clutch initiation are influenced strongly by spring weather patterns. Nineteen species of birds and three species of mammals were used as prey; however, in most years the bulk of the diet consisted of six species of birds and one mammal. A dramatic increase in the density of territorial peregrines in a year of high microtine rodent abundance, coupled with changes in various measures of reproductive performance, suggested that use of lemmings by falcons can be significant in some years. Suggestions that peregrines lay fewer eggs in the arctic part of their range were not supported. Broods hatched asynchronously, with the last-hatched young dying in about one-half of all broods of four. Surviving last-hatched young in broods of four grew at rates similar to older nest mates. Brood size was as high as that for any tundra nesting peregrine population on record.Key words: peregrine falcon, Falco peregrinus tundrius, morphology, migration, food, growth, productivityMots clés: faucon pèlerin, Falco peregrinus tundrius, morphologie, migration, alimentation, croissance, productivité
Simulated ecology-driven sympatric speciation
We introduce a multi-locus genetically acquired phenotype, submitted to
mutations and with selective value, in an age-structured model for biological
aging. This phenotype describes a single-trait effect of the environment on an
individual, and we study the resulting distribution of this trait among the
population. In particular, our simulations show that the appearance of a double
phenotypic attractor in the ecology induces the emergence of a stable
polymorphism, as observed in the Galapagos finches. In the presence of this
polymorphism, the simulations generate short-term speciation, when mating
preferences are also allowed to suffer mutations and acquire selective value.Comment: 11 pages, 5 figures, 1 table, uses package RevTe
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