516 research outputs found

    Assessment of Exercise Capacity and Oxygen Consumption Using a 6 min Stepper Test in Older Adults

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    It is often necessary to assess physical function in older adults to monitor disease progression, rehabilitation or decline in function with age. However, increasing frailty and poor balance that accompany aging are common barriers to exercise testing protocols. We investigated whether a 6-min stepper test (6MST) was acceptable to older adults and provided a measure of exercise capacity and a predicted value for peak aerobic capacity (VO2max). 635 older adults from a tri-ethnic UK population-based cohort were screened to undertake a self-paced 6MST. Expired gas analysis, heart rate and blood pressure monitoring were carried out. A sub-set of 20 participants performed a second 6MST for assessment of reproducibility and a further sub-set of 10 performed the 6-min walk test as verification against a well-recognized and accepted self-paced exercise test. 518 (82%) participants met inclusion criteria and undertook the 6MST (299 men, mean age 71.2 ± 6.4). Step rate showed a strong positive correlation with measured VO2 (r = 0.75, p < 0.001) and VO2 was lower in women (male-female difference in VO2 = 2.61 (95% confidence interval -3.6, -1.7) ml/min/kg; p < 0.001). 20 participants repeated a 6MST, step rate was higher in the second test but the predicted VO2max showed good agreement (mean difference = 0.1 [3.72, 3.95] ml/min/kg). In 10 participants who completed a 6MST and a 6-min walk test there was a strong positive correlation between walking rate and step rate (r = 0.77; p < 0.009) and weaker positive correlations between the tests for measured VO2 and peak heart rate. In conclusion, the 6MST is a convenient, acceptable method of assessing exercise capacity in older adults that allows VO2max to be predicted reproducibly. The test shows good correlation between performance and measured physiological markers of performance and can detect the expected gender differences in measured VO2. Furthermore, the 6MST results correlate with a previously verified and established self-paced exercise test

    Characteristics and racial variations of polypoidal choroidal vasculopathy in tertiary centers in the United States and United Kingdom

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    PURPOSE: To evaluate the characteristics and racial variations amongst patients with polypoidal choroidal vasculopathy (PCV) in the United States and the United Kingdom. METHODS: Fundus photos and indocyanine green angiography images were evaluated in a multicenter retrospective study to establish the diagnosis of PCV. Visual acuity (VA) was recorded in ETDRS letter count. RESULTS: Eighty eyes of 71 PCV patients (average age of 69.4 ± 10.4 years) were included in the analysis. Of the total 71 subjects, 46 (65%) were women, 33 (46.5%) were Blacks, 16 (22.5%) were Whites, 19 (26.8%) were Asians and 3 (4.2%) belonged to other races. The Black subgroup had vision gain of 3.5 letters. The White and Asian subgroups had vision loss of 13.1 and 3.5 letters, respectively. There was female predominance in Blacks (67%), Whites (69%), and Asians (58%). PCV was found to be a bilateral disease in 14 patients (20%). There was significant decrease of 7 letters with every decade increase in age (p = 0.005). Final VA was worse in males when compared to females (p = 0.042), and worse in Whites when compared to Blacks (p = 0.005). For every 10 letters worse in initial VA upon diagnosis with PCV, the final VA was worse by 6 letters (p < 0.001). The location of the polypoidal lesion within the macula was associated with significant decrease of 14 letters in BCVA (p = 0.02). The length of follow up was significantly associated with worse visual outcome (p = 0.012). Final VA had no significant correlation with the lens status, or the different treatment modalities. CONCLUSIONS: Based on our cohort from tertiary centers in the United States and United Kingdom, PCV is a bilateral disease in one-fifth of patients. It features a variable female predominance based on ethnicity. Increased age, worse vision upon initial presentation, longer follow up and macular location of the polyp were associated with worse visual outcome

    Ethnicity and prediction of cardiovascular disease: performance of QRISK2 and Framingham scores in a U.K. tri-ethnic prospective cohort study (SABRE--Southall And Brent REvisited).

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    OBJECTIVE: To evaluate QRISK2 and Framingham cardiovascular disease (CVD) risk scores in a tri-ethnic U.K. population. DESIGN: Cohort study. SETTING: West London. PARTICIPANTS: Randomly selected from primary care lists. Follow-up data were available for 87% of traced participants, comprising 1866 white Europeans, 1377 South Asians, and 578 African Caribbeans, aged 40-69 years at baseline (1998-1991). MAIN OUTCOME MEASURES: First CVD events: myocardial infarction, coronary revascularisation, angina, transient ischaemic attack or stroke reported by participant, primary care or hospital records or death certificate. RESULTS: During follow-up, 387 CVD events occurred in men (14%) and 78 in women (8%). Both scores underestimated risk in European and South Asian women (ratio of predicted to observed risk: European women: QRISK2: 0.73, Framingham: 0.73; South Asian women: QRISK2: 0.52, Framingham: 0.43). In African Caribbeans, Framingham over-predicted in men and women and QRISK2 over-predicted in women. Framingham classified 28% of participants as high risk, predicting 54% of all such events. QRISK2 classified 19% as high risk, predicting 42% of all such events. Both scores performed poorly in identifying high risk African Caribbeans; QRISK2 and Framingham identified as high risk only 10% and 24% of those who experienced events. CONCLUSIONS: Neither score performed consistently well in all ethnic groups. Further validation of QRISK2 in other multi-ethnic datasets, and better methods for identifying high risk African Caribbeans and South Asian women, are required

    Lexicality and frequency in specific language impairment: accuracy and error data from two nonword repetition tests

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    Purpose: Deficits in phonological working memory and deficits in phonological processing have both been considered potential explanatory factors in Specific Language Impairment (SLI). Manipulations of the lexicality and phonotactic frequency of nonwords enable contrasting predictions to be derived from these hypotheses. Method: 18 typically developing (TD) children and 18 children with SLI completed an assessment battery that included tests of language ability, non-verbal intelligence, and two nonword repetition tests that varied in lexicality and frequency. Results: Repetition accuracy showed that children with SLI were unimpaired for short and simple high lexicality nonwords, whereas clear impairments were shown for all low lexicality nonwords. For low lexicality nonwords, greater repetition accuracy was seen for nonwords constructed from high over low frequency phoneme sequences. Children with SLI made the same proportion of errors that substituted a nonsense syllable for a lexical item as TD children, and this was stable across nonword length. Conclusions: The data show support for a phonological processing deficit in children with SLI, where long-term lexical and sub-lexical phonological knowledge mediate the interpretation of nonwords. However, the data also suggest that while phonological processing may provide a key explanation of SLI, a full account is likely to be multi-faceted

    Researching the use of force: The background to the international project

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    This article provides the background to an international project on use of force by the police that was carried out in eight countries. Force is often considered to be the defining characteristic of policing and much research has been conducted on the determinants, prevalence and control of the use of force, particularly in the United States. However, little work has looked at police officers’ own views on the use of force, in particular the way in which they justify it. Using a hypothetical encounter developed for this project, researchers in each country conducted focus groups with police officers in which they were encouraged to talk about the use of force. The results show interesting similarities and differences across countries and demonstrate the value of using this kind of research focus and methodology

    A Novel Run-Time Monitoring Architecture for Safe and Efficient Inline Monitoring

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    20th International Conference on Reliable Software Technologies - Ada-Europe 2015 (Ada-Europe 2015), Madrid, Spain.Verification and testing are two of the most costly and time consuming steps during the development of safety critical systems. The advent of complex and sometimes partially unpredictable computing architectures such as multicore commercial-of-the-shelf platforms, together with the composable development approach adopted in multiple industrial domains such as avionics and automotive, rendered the exhaustive testing of all situations that could potentially be encountered by the system once deployed on the field nearly impossible. Run-time verification (RV) is a promising solution to help accelerate the development of safety critical applications whilst maintaining the high degree of reliability required by such systems. RV adds monitors in the application, which check at run-time if the system is behaving according to predefined specifications. In case of deviations from the specifications during the runtime, safeguarding measures can be triggered in order to keep the system and its environment in a safe state, as well as potentially attempting to recover from the fault that caused the misbehaviour. Most of the state-of-the-art on RV essentially focused on the monitor generation, concentrating on the expressiveness of the specification language and its translation in correct-by-construction monitors. Few of them addressed the problem of designing an efficient and safe run-time monitoring (RM) architecture. Yet, RM is a key component for RV. The RM layer gathers information from the monitored application and transmits it to the monitors. Therefore, without an efficient and safe RM architecture, the whole RV system becomes useless, as its inputs and hence by extension its outputs cannot be trusted. In this paper, we discuss the design of a novel RM architecture suited to safety critical applications
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