166 research outputs found
General geometry of belief function combination
In this paper we build on previous work on the geometry of Dempsterâs rule to investigate the geometric behaviour of various other combination rules, including Yagerâs, Duboisâ, and disjunctive combination, starting from the case of binary frames of discernment. Believability measures for unnormalised belief functions are also considered. A research programme to complete this analysis is outlined
Metric learning for Parkinsonian identification from IMU gait measurements
Diagnosis of people with mild Parkinsonâs symptoms is difficult. Nevertheless, variations in gait pattern can be utilised to this purpose, when measured via Inertial Measurement Units (IMUs). Human gait, however, possesses a high degree of variability across individuals, and is subject to numerous nuisance factors. Therefore, off-the-shelf Machine Learning techniques may fail to classify it with the accuracy required in clinical trials. In this paper we propose a novel framework in which IMU gait measurement sequences sampled during a 10 metre walk are first encoded as hidden Markov models (HMMs) to extract their dynamics and provide a fixed-length representation. Given sufficient training samples, the distance between HMMs which optimises classification performance is learned and employed in a classical Nearest Neighbour classifier. Our tests demonstrate how this technique achieves accuracy of 85.51% over a 156 people with Parkinsonâs with a representative range of severity and 424 typically developed adults, which is the top performance achieved so far over a cohort of such size, based on single measurement outcomes. The method displays the potential for further improvement and a wider application to distinguish other conditions
Alternative formulations of the theory of evidence based on basic plausibility and commonality assignments
In this paper we introduce indeed two alternative formulations of the theory of evidence by proving that both plausibility and commonality functions share the same combinatorial structure of sum function of belief functions, and computing their Moebius inverses called basic plausibility and commonality assignments. The equivalence of the associated formulations of the ToE is mirrored by the geometric congruence of the related simplices. Applications to the probabilistic approximation problem are briefly presented
Dual properties of the relative belief of singletons
In this paper we prove that a recent Bayesian approximation of belief functions, the relative belief of singletons, meets a number of properties with respect to Dempsterâs rule of combination which mirrors those satisfied by the relative plausibility of singletons. In particular, its operator commutes with Dempsterâs sum of plausibility functions, while perfectly representing a plausibility function when combined through Dempsterâs rule. This suggests a classification of all Bayesian approximations into two families according to the operator they relate to
Herbal medicine: women's views, knowledge and interaction with doctors: a qualitative study
BACKGROUND: There is growing concern that serious interactions are occurring between prescribed/over the counter and herbal medicines and that there is a lack of disclosure of herbal use by patients to doctors. This study explores women's perspectives about the safety of herbal remedies, herb-drug interactions and communication with doctors about herbal medicines. METHODS: Qualitative, cross-sectional study, with purposive sampling which took place in Cheshire, UK. Eighteen in depth semi-structured interviews were conducted with female herbal medicine users aged 18 years and above. RESULTS: The large majority did not inform their GPs of their use of herbal medicines. This was due to lack of physician enquiry, perception of importance and fear of a negative response. Several women were not aware that herbal remedies could interact with prescribed or over the counter medicines. Of the women who had experienced adverse effects none had reported them, believing them of low importance. CONCLUSION: The women had little knowledge about herb-drug interactions and rarely disclosed use of herbal medicines to their doctor. Doctors' communication and openness regarding herbal medicines needs to improve and there should be increased access to accurate information on herbal medicines in the public and health care domain
Generalised max entropy classifiers
In this paper we propose a generalised maximum-entropy classification framework, in which the empirical expectation of the feature functions is bounded by the lower and upper expectations associated with the lower and upper probabilities associated with a belief measure. This generalised setting permits a more cautious appreciation of the information content of a training set. We analytically derive the KarushKuhn-Tucker conditions for the generalised max-entropy classifier in the case in which a Shannon-like entropy is adopted
Practices of healthcare professionals in communicating with nonsteroidal antiâinflammatory drug users in Thailand: a qualitative study
Objective; This study aimed to explore practices among healthcare professionals in nonsteroidal anti-inflammatory drug (NSAID) information provision.
Methods; In-depth interviews were conducted with orthopaedic physicians, hospital and community pharmacists in northeastern Thailand. Ten hospitals and twenty pharmacies in five provinces were purposively selected. Interviews followed a topic guideline, were audio-recorded, transcribed verbatim and analyzed using a framework approach.
Key findings; Fifty-one participants were involved: 13 orthopedic physicians, 20 hospital pharmacists and 18 community pharmacists. Four main themes emerged: general information, safety information, differences between new and regular NSAID users and non-selective and selective NSAID users. Pharmacists mostly provided information on administration and indication. While all three groups informed of adverse effects, this was selective, related to factors including trading, time available, patientsâ age, and perceived ability to understand. Gastrointestinal adverse effect information was most commonly provided, with other side effects, drug interactions and need to monitor for adverse effects rarely mentioned. Variation was reported in provision of safety information depending on whether patients were using selective or non-selective NSAIDs, and new or long-term users.
Conclusions; The content and frequency of NSAID information provision varied between health professionals. Greater awareness of NSAID risks is essential, therefore strategies to improve information provision to Thai patients are desirable
Pregnancy, prescription medicines and the potential risk of herb-drug interactions:a cross-sectional survey
Funding All funding was from institutional resource. JSM, AS are employed by the University of Aberdeen. DS is employed by the Robert Gordon University. BP and CR are employed by NHS Scotland. ARP and MAH are employed by the Hamad Medical Corporation. Qatar. NI is a postgraduate student at the University of Aberdeen.Peer reviewedPublisher PD
Structure and dynamics of the active Gs-coupled human secretin receptor
The class B secretin GPCR (SecR) has broad physiological effects, with target potential for treatment of metabolic and cardiovascular disease. Molecular understanding of SecR binding and activation is important for its therapeutic exploitation. We combined cryo-electron microscopy, molecular dynamics, and biochemical cross-linking to determine a 2.3âĂ
structure, and interrogate dynamics, of secretin bound to the SecR:Gs complex. SecR exhibited a unique organization of its extracellular domain (ECD) relative to its 7-transmembrane (TM) core, forming more extended interactions than other family members. Numerous polar interactions formed between secretin and the receptor extracellular loops (ECLs) and TM helices. Cysteine-cross-linking, cryo-electron microscopy multivariate analysis and molecular dynamics simulations revealed that interactions between peptide and receptor were dynamic, and suggested a model for initial peptide engagement where early interactions between the far N-terminus of the peptide and SecR ECL2 likely occur following initial binding of the peptide C-terminus to the ECD
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