5,791 research outputs found
Learning New Facts From Knowledge Bases With Neural Tensor Networks and Semantic Word Vectors
Knowledge bases provide applications with the benefit of easily accessible,
systematic relational knowledge but often suffer in practice from their
incompleteness and lack of knowledge of new entities and relations. Much work
has focused on building or extending them by finding patterns in large
unannotated text corpora. In contrast, here we mainly aim to complete a
knowledge base by predicting additional true relationships between entities,
based on generalizations that can be discerned in the given knowledgebase. We
introduce a neural tensor network (NTN) model which predicts new relationship
entries that can be added to the database. This model can be improved by
initializing entity representations with word vectors learned in an
unsupervised fashion from text, and when doing this, existing relations can
even be queried for entities that were not present in the database. Our model
generalizes and outperforms existing models for this problem, and can classify
unseen relationships in WordNet with an accuracy of 75.8%
Exercise for falls prevention in community-dwelling older adults: Trial and participant characteristics, interventions and bias in clinical trials from a systematic review
IntroductionThere is strong evidence that exercise prevents falls in community-dwelling older people. This review summarises trial and participant characteristics, intervention contents and study quality of 108 randomised trials evaluating exercise interventions for falls prevention in community-dwelling older adults.MethodsMEDLINE, EMBASE, CENTRAL and three other databases sourced randomised controlled trials of exercise as a single intervention to prevent falls in community-dwelling adults aged 60+ years to May 2018.Results108 trials with 146 intervention arms and 23 407 participants were included. Trials were undertaken in 25 countries, 90% of trials had predominantly female participants and 56% had elevated falls risk as an inclusion criterion. In 72% of trial interventions attendance rates exceeded 50% and/or 75% of participants attended 50% or more sessions. Characteristics of the trials within the three types of intervention programme that reduced falls were: (1) balance and functional training interventions lasting on average 25 weeks (IQR 16–52), 39% group based, 63% individually tailored; (2) Tai Chi interventions lasting on average 20 weeks (IQR 15–43), 71% group based, 7% tailored; (3) programmes with multiple types of exercise lasting on average 26 weeks (IQR 12–52), 54% group based, 75% tailored. Only 35% of trials had low risk of bias for allocation concealment, and 53% for attrition bias.ConclusionsThe characteristics of effective exercise interventions can guide clinicians and programme providers in developing optimal interventions based on current best evidence. Future trials should minimise likely sources of bias and comply with reporting guidelines
Self-Reported Hearing Handicap and Mental Health in Australia: Some Preliminary Findings
"Article Copyright 2012 The Authors."
"Published edition Copyright 2012 Australian Academic Press. Published version of the paper reproduced here with permission from the publisher."It has long been suggested that the consequences of adult hearing impairment (HI) include stress, anxiety and depression, yet relatively little formal assessment of mental health status amongst adult Australians who have acquired HI has been reported. This questionnaire- based study investigated the self-reported hearing handicap and mental health characteristics of a sample of 375 Australian adults with HI who were members of Better Hearing Australia (BHA) in six Australian states/territories. Participants completed two mental health questionnaires; the Kessler Psychological Distress Scale-10 (K-10; Kessler, Andrews, Colpe, & Hiripi, 2002) and the Depression- Anxiety-Stress Scale (DASS; Lovibond & Lovibond, 1995) as well as the short version of the Hearing Handicap Inventory for Adults — Screening Version (HHIA-S; Newman, Weinstein, Jacobson, & Hug, 1990). No difference was found in the prevalence of psychological distress amongst participants compared to that of the Australian adult population. It was noted, however, that increased severity of self-reported hearing handicap was associated with higher levels of self-perceived psychological distress. In turn, high or very high levels of psychological distress measured on the K-10 were correlated with depressive states more than with stress or anxiety ratings on the DASS. The results highlighted the need to incorporate a combination of questionnaire-based measures in evaluating self-reported mental health and hearing handicap
Influence of seed aerosol surface area and oxidation rate on vapor wall deposition and SOA mass yields: a case study with α-pinene ozonolysis
Laboratory chambers, invaluable in atmospheric chemistry and aerosol formation studies, are subject to particle and vapor wall deposition, processes that need to be accounted for in order to accurately determine secondary organic aerosol (SOA) mass yields. Although particle wall deposition is reasonably well understood and usually accounted for, vapor wall deposition is less so. The effects of vapor wall deposition on SOA mass yields in chamber experiments can be constrained experimentally by increasing the seed aerosol surface area to promote the preferential condensation of SOA-forming vapors onto seed aerosol. Here, we study the influence of seed aerosol surface area and oxidation rate on SOA formation in α-pinene ozonolysis. The observations are analyzed using a coupled vapor–particle dynamics model to interpret the roles of gas–particle partitioning (quasi-equilibrium vs. kinetically limited SOA growth) and α-pinene oxidation rate in influencing vapor wall deposition. We find that the SOA growth rate and mass yields are independent of seed surface area within the range of seed surface area concentrations used in this study. This behavior arises when the condensation of SOA-forming vapors is dominated by quasi-equilibrium growth. Faster α-pinene oxidation rates and higher SOA mass yields are observed at increasing O3 concentrations for the same initial α-pinene concentration. When the α-pinene oxidation rate increases relative to vapor wall deposition, rapidly produced SOA-forming oxidation products condense more readily onto seed aerosol particles, resulting in higher SOA mass yields. Our results indicate that the extent to which vapor wall deposition affects SOA mass yields depends on the particular volatility organic compound system and can be mitigated through the use of excess oxidant concentrations
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