Distribution Entropy (DistEn) : a complexity measure to detect arrhythmia from short length RR interval time series

Heart rate complexity analysis is a powerful non-invasive means to diagnose several cardiac ailments. Non-linear tools of complexity measurement are indispensable in order to bring out the complete non-linear behavior of Physiological signals. The most popularly used non-linear tools to measure signal complexity are the entropy measures like Approximate entropy (ApEn) and Sample entropy (SampEn). But, these methods become unreliable and inaccurate at times, in particular, for short length data. Recently, a novel method of complexity measurement called Distribution Entropy (DistEn) was introduced, which showed reliable performance to capture complexity of both short term synthetic and short term physiologic data. This study aims to i) examine the competence of DistEn in discriminating Arrhythmia from Normal sinus rhythm (NSR) subjects, using RR interval time series data; ii) explore the level of consistency of DistEn with data length N; and iii) compare the performance of DistEn with ApEn and SampEn. Sixty six RR interval time series data belonging to two groups of cardiac conditions namely `Arrhythmia' and `NSR' have been used for the analysis. The data length N was varied from 50 to 1000 beats with embedding dimension m = 2 for all entropy measurements. Maximum ROC area obtained using ApEn, SampEn and DistEn were 0.83, 0.86 and 0.94 for data length 1000, 1000 and 500 beats respectively. The results show that DistEn undoubtedly exhibits a consistently high performance as a classification feature in comparison with ApEn and SampEn. Therefore, DistEn shows a promising behavior as bio marker for detecting Arrhythmia from short length RR interval data.

A novel technique for analysing beat-to-beat dynamical changes of QT-RR distribution for arrhythmia prediction

Ventricular tachycardia (VT) leading to ventricular fibrillation (VF) is the major cause of sudden cardiac death (SCD) with subjects with or without any history of cardiac disease. Prediction of the initiation of ventricular fibrillation is crucial for both successful preventive measure and effective defibrillation therapy. A lot of studies have been done based on electrocardiogram (ECG) waveform analysis for VF detection but this field still needs more perfection. Both HRV and QTV related parameters were reported to be analysed for VT/VF detection and prediction with inconsistent results in different populations. In this study, we propose a novel time domain measurement tool to detect the pattern of dynamical changes of both RR and QT intervals in subjects having sustained VT/VF episodes form VFDB and AHA database (www.physionet.org). We also analyse the same pattern in some healthy subjects from Fantasia database and compare the distribution of patterns between healthy and VT/VF subjects. Our findings showed that the distribution of QT-RR dynamics are statistically significantly different (p<0.05) in healthy subjects from VT/VF in particular before the start of VF episode. Therefore, distribution of change in QT-RR dynamics may provide insight of the underlying instability before VF events and can be used for better prediction of arhythmogenesis.

Neglect dyslexia with a stimulus-centred deficit and without visuospatial neglect.

This paper reports a single case of ipsilesional left neglect dyslexia and interprets it according to the three-level model of visual word recognition proposed by Caramazza and Hillis (1990). The three levels reflect a progression from the physical stimulus to an abstract representation of a word. RR was not impaired at the first, retinocentric, level, which represents the individual features of letters within a word according to the location of the word in the visual field: She made the same number of errors to words presented in her left visual field as in her right visual field. A deficit at this level should also mean the patient neglects all stimuli. This did not occur with RR: She did not neglect when naming the items in rows of objects and rows of geometric symbols. In addition, although she displayed significant neglect dyslexia when making visual matching judgements on pairs of words and nonwords, she did not do so to pairs of nonsense letter shapes, shapes which display the same level of visual complexity as letters in words. RR was not impaired at the third, graphemic, level, which represents the ordinal positions of letters within a word: She continued to neglect the leftmost (spatial) letter of words presented in mirror-reversed orientation and she did not neglect in oral spelling. By elimination, these results suggest RR's deficit affects a spatial reference frame where the representational space is bounded by the stimulus: A stimulus-centred level of representation. We define five characteristics of a stimulus-centred deficit, as manifest in RR. First, it is not the case that neglect dyslexia occurs because the remaining letters in a string attract or capture attention away from the leftmost letter(s). Second, the deficit is continuous across the letter string. Third, perceptually significant features, such as spaces, define potential words. Fourth, the whole, rather than part, of a letter is neglected. Fifth, category information is preserved. It is concluded that the Caramazza-Hillis model accounts well for RR's data, although we conclude that neglect dyslexia can be present when a more general visuospatial neglect is absent.

Decreased fatty acit Â-oxidation in riboflavin-responsive, multiple acylocoenzyme a dehydrogenase-deficient patients is associated with an increase in uncoupling protein-3

Riboflavin-responsive, multiple acylcoenzyme A dehydrogenase deficiency (RR-MAD), a lipid storage myopathy, is characterized by, among others, a decrease in fatty acid (FA) ß-oxidation capacity. Muscle uncoupling protein 3 (UCP3) is up-regulated under conditions that either increase the levels of circulating free FA and/or decrease FA ß-oxidation. Using a relatively large cohort of seven RR-MAD patients, we aimed to better characterize the metabolic disturbances of this disease and to explore the possibility that it might increase UCP3 expression. A battery of biochemical and molecular tests were performed, which demonstrated decreases in FA ß-oxidation and in the activities of respiratory chain complexes I and II. These metabolic alterations were associated with increases of 3.1- and 1.7-fold in UCP3 mRNA and protein expression, respectively. All parameters were restored to control values after riboflavin treatment. We postulate that the up-regulation of UCP3 in RR-MAD is due to the accumulation of muscle FA/acylCoA. RR-MAD is an optimal model to support the hypothesis that UCP3 is involved in the outward translocation of an excess of FA from the mitochondria and to show that, in humans, the effects of FA on UCP3 expression are direct and independent of fatty acid ß-oxidation.

Patellar tendons with normal imaging and pain: change in imaging and pain status over volleyball season

Objective: Patellar tendon injury commonly presents as abnormal imaging with pain or abnormal imaging without pain. Normal imaging with pain has also been reported clinically, but little is known about the behavior of these tendons over time. This study investigated the behavior of tendons with normal imaging and pain over a volleyball season.

Design: Prospective study.

Setting: Institutional.

Participants: One hundred and one male and female volleyball players.

Main outcome measurements: At the beginning and end of the season ultrasound determined imaging status and the single leg decline squat test determined pain. The imaging and pain status at follow-up of tendons with normal imaging and pain at baseline was reported and contrasted to the imaging and pain status of the other patellar tendon injuries.

Results: Tendons with normal imaging and pain [relative risk (RR) 15.1], abnormal imaging without pain (RR 14.6), and abnormal imaging with pain (RR 51.5) had a greater risk of having abnormal imaging with pain at the end of the season when compared with normal tendons (P < 0.01). Among tendons with normal imaging and pain at baseline, 27% had abnormal imaging without pain and 21% contained abnormal imaging with pain at the end of the season.

Conclusions: Patellar tendons with normal imaging and pain at the beginning of a volleyball season are equally as likely to have abnormal imaging and pain at the end of the season as tendons with abnormal imaging without pain. Normal imaging with pain may represent a clinically relevant patellar tendon injury.

Knowledge, attitudes and self-care practices related to sun protection among secondary students in Australia

The aim of this research was to ascertain changes in sun-related knowledge, attitudes and self-care practices among Australian secondary school students between 1993 and 1996. Two cross-sectional surveys of sun-related attitudes, beliefs and behavior of young people aged 12–17 years of age, were conducted in 1993 and 1996. Over 80% of adolescents at both time periods knew about the issues related to skin cancer prevention, frequency of burning and burning on cloudy days. Adolescent attitudes had shifted positively in the areas of staying inside in 1996 [relative risk (RR): 1.13; 95% confidence interval (CI): 1.09–1.17] and staying under shade in 1996 (RR: 1.16; 95% CI: 1.13–1.18). Desire for a moderate or dark tan was lower in 1996 (45%) than in 1993 (50%). Respondents reported that they were less likely to wear brief clothing to get a suntan in 1996 (RR: 0.81; 95% CI: 0.78–0.84) and were significantly more likely to stay in the shade in 1996 (RR: 1.19; 95% CI: 1.16–1.23). We conclude that there has been a shift in attitudes towards use of shade and avoidance of unnecessary exposure, and away from use of sunscreens and sunglasses. The results suggest that adolescents may be more ready to accept structural changes that move desired activities out of the sun.

An aspect of mathematical understanding: the notion of 'connected knowing'

Much advice about teaching for understanding implies that teacher should help children to develop connections between aspects of their experience, knowledge, and skills. This paper outlines points from the literature about different types of connections and describes relevant points from four case study teachers said and did.

Assessment as a strategic tool for enhancing learning in teacher education: a case study

This small exploratory case study describes an attempt to integrate the academic and practical aspects of a teacher education course in order to promote deep understanding of children's ways of understanding mathematics. The assessment regime of the course was used as a strategic tool for engaging students, and the assessment tasks themselves were used as the means of generating genuine integration, or case knowledge, of the content of the course. The results indicate that the approach was effective in achieving the aims of the course, and student reaction to the approach was extremely positive.

Increased consumption of fruit and vegetables is related to a reduced risk of coronary heart disease: meta-analysis of cohort studies

Increased consumption of fruit and vegetables has been shown to be associated with a reduced risk of coronary heart disease (CHD) in many epidemiological studies, however, the extent of the association is uncertain. We quantitatively assessed the relation between fruit and vegetable intake and incidence of CHD by carrying out a meta-analysis of cohort studies. Studies were included if they reported relative risks (RRs) and corresponding 95% confidence interval (CI) of CHD with respect to frequency of fruit and vegetable intake. Twelve studies, consisting of 13 independent cohorts, met the inclusion criteria. There were 278 459 individuals (9143 CHD events) with a median follow-up of 11 years. Compared with individuals who had less than 3 servings/day of fruit and vegetables, the pooled RR of CHD was 0.93 (95% CI: 0.86–1.00, P=0.06) for those with 3–5 servings/day and 0.83 (0.77–0.89, P<0.0001) for those with more than 5 servings/day. Subgroup analyses showed that both fruits and vegetables had a significant protective effect on CHD. Our meta-analysis of prospective cohort studies demonstrates that increased consumption of fruit and vegetables from less than 3 to more than 5 servings/day is related to a 17% reduction in CHD risk, whereas increased intake to 3–5 servings/day is associated with a smaller and borderline significant reduction in CHD risk. These results provide strong support for the recommendations to consume more than 5 servings/day of fruit and vegetables.

Injury profiles of Indigenous and non-Indigenous people in New South Wales

Objectives:
To compare the injury profiles of the Indigenous population in New South Wales with that of the non-Indigenous population.
Design and setting:
Descriptive analysis of NSW Health data obtained from the Health Outcomes Information and Statistical Toolkit (HOIST) database. Hospitalisation data were collected for the period 1 July 1999 to 30 June 2003. Mortality data were collected for the period 1 January 1999 to 31 December 2002.
Main outcome measures:
Hospitalisation and death rates due to injury by age, sex, injury mechanism and Indigenous status. Rate ratios for comparison between Indigenous and non-Indigenous populations.
Results:
Rates of death from injury were higher for all age groups in the Indigenous population, except people older than 65 years. Indigenous people aged 25–44 years were twice as likely to be hospitalised as their non-Indigenous counterparts (rate ratio [RR], 2.09; 95% CI, 2.03–2.14), and five times as likely to be hospitalised for interpersonal violence (RR, 5.19; 95% CI, 4.98–5.40).
Conclusion:
The higher rates of injury-related hospitalisation and death in the Indigenous population in NSW are consistent with data reported for other parts of Australia. Of particular concern is the number of Indigenous deaths and hospitalisations due to interpersonal violence.

Interventions for educating children who have attended the emergency room for asthma (Review)

Background: Asthma is one of the most common reasons for paediatric admissions to hospital, with substantial cost to the community. There is some evidence to suggest that many hospital admissions could be prevented with effective education about asthma and its management.
Objectives: To conduct a systematic review of the literature in order to identify whether asthma education leads to improved health outcomes in children who have attended the emergency department for asthma.
Search strategy: We searched the Cochrane Airways Group trials register, including MEDLINE, EMBASE, and CINAHL databases, and reference lists of trials and review articles.
Selection criteria: Randomised controlled trials or controlled clinical trials of asthma education for children who had attended the emergency department for asthma, with or without hospitalisation, within the previous 12 months. Data collection and analysis:Two reviewers independently assessed trial quality and extracted data. Study authors were contacted for additional information.
Main results: Eight trials involving 1407 patients were included, in all the education was provided by nurses or researchers. Compared to control (usual care or lower intensity education) education did not reduce subsequent emergency department (ED) visits [4 trials; relative risk (RR)= 0.87, 95% confidence interval (CI) 0.37 to 2.08], hospital admissions [5 trials; RR=0.74, 95% CI 0.38 to 1.46] and unscheduled doctor visits [5 trials; RR= 0.74, 95% CI 0.49 to 1.12). Each analysis showed evidence of heterogeneity among the studies (P<0.01). Subgroup analyses by the overall difference in scale of intervention between treatment and control groups (comprehensive programme versus information only) or the timing of the intervention/recruitment (early versus delayed) gave similar results to the main analysis and still revealed significant heterogeneity between trials. Authors' conclusions: On the basis of the published trials, there is no firm evidence to support the use of asthma education for children who have attended the emergency department for asthma as a means of reducing subsequent ED visits, hospital admissions or unscheduled doctor visits. Some trials appeared to show clear evidence of benefit, but reasons for differences between these and the negative studies is not clear. More research is required.

Describing elements of mathematics lessons that accommodate diversity in student background

We are researching actions that teachers can take to improve mathematics learning for all students. Structural elements of the lessons being trialled include making aspects of pedagogy explicit to seek to overcome differences in familiarity with schooling processes, and sequencing tasks with the potential to engage students. This article reports research on teachers building learning communities by preparing variations to set tasks in order to address differences in students’ backgrounds.

Overweight and obesity from childhood to adulthood: a follow-up of participants in the 1985 Australian Schools Health and Fitness Survey

Objective: To examine overweight and obesity in Australian children followed through to adulthood.

Design and participants: A cohort study of 8498 children aged 7–15 years who participated in the 1985 Australian Schools Health and Fitness Survey; of these, 2208 men and 2363 women completed a follow-up questionnaire at age 24–34 years in 2001–2005.

Main outcome measures: Height and weight were measured in 1985, and self-reported at follow-up. The accuracy of self-reported data was checked in 1185 participants. Overweight and obesity in childhood were defined according to international standard definitions for body mass index (BMI), and, in adulthood, as a BMI of 25–29.9 and ≥ 30 kg/m2, respectively, after correcting for self-report error.

Results: In those with baseline and follow-up data, the prevalence of overweight and obesity in childhood was 8.3% and 1.5% in boys and 9.7% and 1.4% in girls, respectively. At follow-up, the prevalence was 40.1% and 13.0% in men and 19.7% and 11.7% in women. The relative risk (RR) of becoming an obese adult was significantly greater for those who had been obese as children compared with those who had been a healthy weight (RR = 4.7; 95% CI, 3.0–7.2 for boys and RR = 9.2; 95% CI, 6.9–12.3 for girls). The proportion of adult obesity attributable to childhood obesity was 6.4% in males and 12.6% in females.

Conclusion: Obesity in childhood was strongly predictive of obesity in early adulthood, but most obese young adults were a healthy weight as children.

Markers and risk factors for HCV, HBV and HIV in a network of injecting drug users in Melbourne

Background and aims: Current injecting drug users (IDU) in major street drug markets within greater Melbourne were recruited to a longitudinal study on blood borne viruses. Here we investigated risk factors for hepatitis C virus (HCV), hepatitis B virus (HBV) and HIV infection in these IDU at the time of their recruitment.

Methods : Three hundred and eighty-two IDU completed detailed questionnaires on their drug use and risk behaviours, and provided blood samples for serology testing. These data were analysed using univariate and multivariate techniques.

Results : The overall prevalence of exposure to HCV, HBV and HIV was estimated at 70%, 34% and <1%, respectively. Independent predictors of HCV exposure were history of imprisonment (RR 1.34, 95% CI 1.19–1.52), use of someone else's needle or syringe (RR 1.23, 95% CI 1.07–1.42), >7.6 years length of time injecting (RR 1.21, 95% CI 1.07–1.37), and originating from Vietnam (RR 1.12, 95% CI 1.07–1.18). Independent predictors of HBV exposure were HCV exposure (RR 2.15, 95% CI 1.35–3.43), >7.6 years length of time injecting (RR 1.57, 95% CI 1.17–2.13) and originating from outside Australia (RR 1.60, 95% CI 1.22–2.10). Neither prison- nor community-applied tattoos predicted HCV or HBV exposure. Up to 31% of IDU who injected for 1 year or less were HCV antibody positive, as were 53% of those who injected for 2 years or less.

Conclusions : Ongoing engagement with young IDU, through the provision of harm reduction education and resources, is critical if we are to address blood borne viral infections and other health and social harms associated with injecting drug use.

The use of auricular examination for screening heaptic disorders

Researches on auricular acupuncture (AA) have examined mainly its treatment effects. This study aimed to investigate the accuracy and precision of using auricular examination (AE) as a complementary diagnostic tool for screening hepatic disorders. Twenty patients suffering from liver dysfunction and 25 controls aged 18–60 years were recruited from an acute hospital. Participants were examined using three AE methods including visual inspection, electrical skin resistance measurement, and tenderness testing on the liver AA zone of both ears. Significant differences were found in visual inspection and electrical skin resistance on the AA zones between the two groups. Patients suffering from liver dysfunction tended to have at least one abnormality in skin color, appearance, presence of papules, abundance of capillary and desquamation on the ear (Relative Risk—Right ear: RR = 2.9, 95% confidence interval (CI) 1.4, 6.2; Left: RR = 1.8, 95% CI, 1.01, 3.1). The sensitivity for visual inspection was 0.7 for both ears; specificity was 0.76 for the (R) and 0.6 for the (L) ear. The mean difference in electrical skin resistance was 4.3 MΩ (95% CI, 1.7, 6.9) for the (L) ear; 4.5 MΩ (95% CI, 1.5, 7.6) for the (R) ear. Our results suggest that malfunction of the liver appeared to be reflected by the presence of morphological changes on the liver AA zone. Visual inspection and electrical skin resistance on the liver AA zone are potentially sensitive to screen hepatic disorders.