1,858 research outputs found
Veterinary services during the COVID pandemic: less stressful for cats and their carers?
OBJECTIVES: The COVID-19 pandemic saw major changes to small animal veterinary practice, many of which may have had an impact on stress in cats presented to the clinic. The aim of this study was to examine the nature of feline outpatient visits before and during the pandemic, and examine signs of stress noted in cats before, during and after these visits. METHODS: A questionnaire was used to gather data on cat owner experiences of visits to the veterinary clinic. Data were gathered on the owner’s most recent experience of a consultation, with consultations occurring in February 2020 or earlier coded as a standard consultation, and consultations occurring in March 2020 or later coded as COVID-19 consultations. RESULTS: A total of 371 responses were received, with 210 coded as standard consultations and 161 coded as COVID-19 consultations. Consultation type varied significantly between standard and COVID-19 consultations (P <0.001), with emergency consultations more frequent and preventive healthcare consultations less frequent during the COVID-19 pandemic. The area in which the owner and their cat waited also varied significantly between standard and COVID-19 consultations (P <0.001), with standard consultations more likely to involve time in a waiting room while COVID-19 consultations were often called straight in or waited outside the practice. Most owners notedbehaviours associated with stress in their cats, regardless of consultation type, although trying to hide or escape were noted more frequently for cats seen prior to the COVID-19 pandemic. CONCLUSIONS AND RELEVANCE: The findings suggest that outpatient visits to the veterinary clinic were stressful for cats both prior to and during the COVID-19 pandemic, but some measures taken during the pandemic, for example less use of waiting rooms, could be used alongside existing cat friendly measures to help to reduce stress in feline patients
Guaranteeing Safety of Learned Perception Modules via Measurement-Robust Control Barrier Functions
Modern nonlinear control theory seeks to develop feedback controllers that endow systems with properties such as safety and stability. The guarantees ensured by these controllers often rely on accurate estimates of the system state for determining control actions. In practice, measurement model uncertainty can lead to error in state estimates that degrades these guarantees. In this paper, we seek to unify techniques from control theory and machine learning to synthesize controllers that achieve safety in the presence of measurement model uncertainty. We define the notion of a Measurement-Robust Control Barrier Function (MR-CBF) as a tool for determining safe control inputs when facing measurement model uncertainty. Furthermore, MR-CBFs are used to inform sampling methodologies for learning-based perception systems and quantify tolerable error in the resulting learned models. We demonstrate the efficacy of MR-CBFs in achieving safety with measurement model uncertainty on a simulated Segway system
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Chimpanzees demonstrate individual differences in social information use
Studies of transmission biases in social learning have greatly informed our understanding of how behaviour patterns may diffuse through animal populations, yet within-species inter-individual variation in social information use has received little attention and remains poorly understood. We have addressed this question by examining individual performances across multiple experiments with the same population of primates. We compiled a dataset spanning 16 social learning studies (26 experimental conditions) carried out at the same study site over a 12-year period, incorporating a total of 167 chimpanzees. We applied a binary scoring system to code each participant’s performance in each study according to whether they demonstrated evidence of using social information from conspecifics to solve the experimental task or not (Social Information Score—‘SIS’). Bayesian binomial mixed effects models were then used to estimate the extent to which individual differences influenced SIS, together with any effects of sex, rearing history, age, prior involvement in research and task type on SIS. An estimate of repeatability found that approximately half of the variance in SIS was accounted for by individual identity, indicating that individual differences play a critical role in the social learning behaviour of chimpanzees. According to the model that best fit the data, females were, depending on their rearing history, 15–24% more likely to use social information to solve experimental tasks than males. However, there was no strong evidence of an effect of age or research experience, and pedigree records indicated that SIS was not a strongly heritable trait. Our study offers a novel, transferable method for the study of individual differences in social learning
Sources of light-absorbing aerosol in arctic snow and their seasonal variation
Two data sets consisting of measurements of light absorbing aerosols (LAA) in arctic snow together with suites of other corresponding chemical constituents are presented; the first from Siberia, Greenland and near the North Pole obtained in 2008, and the second from the Canadian arctic obtained in 2009. A preliminary differentiation of the LAA into black carbon (BC) and non-BC LAA is done. Source attribution of the light absorbing aerosols was done using a positive matrix factorization (PMF) model. Four sources were found for each data set (crop and grass burning, boreal biomass burning, pollution and marine). For both data sets, the crops and grass biomass burning was the main source of both LAA species, suggesting the non-BC LAA was brown carbon. Depth profiles at most of the sites allowed assessment of the seasonal variation in the source strengths. The biomass burning sources dominated in the spring but pollution played a more significant (though rarely dominant) role in the fall, winter and, for Greenland, summer. The PMF analysis is consistent with trajectory analysis and satellite fire maps
Towards Robust Data-Driven Control Synthesis for Nonlinear Systems with Actuation Uncertainty
Modern nonlinear control theory seeks to endow systems with properties such as stability and safety, and has been deployed successfully across various domains. Despite this success, model uncertainty remains a significant challenge in ensuring that model-based controllers transfer to real world systems. This paper develops a data-driven approach to robust control synthesis in the presence of model uncertainty using Control Certificate Functions (CCFs), resulting in a convex optimization based controller for achieving properties like stability and safety. An important benefit of our framework is nuanced data-dependent guarantees, which in principle can yield sample-efficient data collection approaches that need not fully determine the input-to-state relationship. This work serves as a starting point for addressing important questions at the intersection of nonlinear control theory and non-parametric learning, both theoretical and in application. We validate the proposed method in simulation with an inverted pendulum in multiple experimental configurations
Neuronal pathways in tendon healing and tendinopathy : update
The regulatory mechanisms involved in tendon homeostasis and repair are not fully understood. Accumulating data, however, demonstrate that the nervous system, in addition to afferent (sensory) functions, through efferent neuronal pathways plays an active role in regulating pain, inflammation, and tissue repair processes.
Thus, in normal-, healing- and tendinopathic tendons three major neuronal signalling pathways consisting of autonomic, sensory and glutamatergic neuromediators have been established. In healthy tendons, these neural elements are found in the paratenon, whereas the proper tendon is practically devoid of nerves, reflecting that normal tendon homeostasis is regulated by pro- and anti-inflammatory mediators from the tendon surroundings. During tendon repair, however, there is extensive nerve ingrowth into the tendon proper and subsequent time-dependent appearance of sensory, autonomic and glutamatergic mediators, which amplify and fine-tune inflammation and tendon regeneration. In tendinopathy, excessive and protracted sensory and glutamatergic signalling may be involved in inflammatory, painful and hypertrophic tissue reactions.
As our understanding of these processes improves, neuronal mediators may prove to be useful in the development of targeted pharmacotherapy and tissue engineering approaches to painful, degenerative and traumatic tendon disorders.Swedish Research Council (project nr. 2012-3510)Stockholm County Council and Karolinska Institutet (project nr. SLL20100168)Swedish National Centre for Sports ResearchCOREF-Sweden grantAlberta Innovates Health Solutions OA Team GrantAccepte
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