On biometric systems: electrocardiogram Gaussianity and data synthesis.

Electrocardiogram is a slow signal to acquire, and it is prone to noise. It can be inconvenient to collect large number of ECG heartbeats in order to train a reliable biometric system; hence, this issue might result in a small sample size phenomenon which occurs when the number of samples is much smaller than the number of observations to model. In this paper, we study ECG heartbeat Gaussianity and we generate synthesized data to increase the number of observations. Data synthesis, in this paper, is based on our hypothesis, which we support, that ECG heartbeats exhibit a multivariate normal distribution; therefore, one can generate ECG heartbeats from such distribution. This distribution is deviated from Gaussianity due to internal and external factors that change ECG morphology such as noise, diet, physical and psychological changes, and other factors, but we attempt to capture the underlying Gaussianity of the heartbeats. When this method was implemented for a biometric system and was examined on the University of Toronto database of 1012 subjects, an equal error rate (EER) of 6.71% was achieved in comparison to 9.35% to the same system but without data synthesis. Dimensionality reduction is widely examined in the problem of small sample size; however, our results suggest that using the proposed data synthesis outperformed several dimensionality reduction techniques by at least 3.21% in EER. With small sample size, classifier instability becomes a bigger issue and we used a parallel classifier scheme to reduce it. Each classifier in the parallel classifier is trained with the same genuine dataset but different imposter datasets. The parallel classifier has reduced predictors' true acceptance rate instability from 6.52% standard deviation to 1.94% standard deviation.

On biometric systems: electrocardiogram Gaussianity and data synthesis.

Electrocardiogram is a slow signal to acquire, and it is prone to noise. It can be inconvenient to collect large number of ECG heartbeats in order to train a reliable biometric system; hence, this issue might result in a small sample size phenomenon which occurs when the number of samples is much smaller than the number of observations to model. In this paper, we study ECG heartbeat Gaussianity and we generate synthesized data to increase the number of observations. Data synthesis, in this paper, is based on our hypothesis, which we support, that ECG heartbeats exhibit a multivariate normal distribution; therefore, one can generate ECG heartbeats from such distribution. This distribution is deviated from Gaussianity due to internal and external factors that change ECG morphology such as noise, diet, physical and psychological changes, and other factors, but we attempt to capture the underlying Gaussianity of the heartbeats. When this method was implemented for a biometric system and was examined on the University of Toronto database of 1012 subjects, an equal error rate (EER) of 6.71% was achieved in comparison to 9.35% to the same system but without data synthesis. Dimensionality reduction is widely examined in the problem of small sample size; however, our results suggest that using the proposed data synthesis outperformed several dimensionality reduction techniques by at least 3.21% in EER. With small sample size, classifier instability becomes a bigger issue and we used a parallel classifier scheme to reduce it. Each classifier in the parallel classifier is trained with the same genuine dataset but different imposter datasets. The parallel classifier has reduced predictors' true acceptance rate instability from 6.52% standard deviation to 1.94% standard deviation.

Understanding the role of the healthcare professional in patient self-management of allergic rhinitis.

OBJECTIVE: Allergic rhinitis is a common, usually long-standing, condition that may be self-diagnosed or have a formal diagnosis. Our aim was to identify how allergic rhinitis sufferers self-manage their condition. METHODS: A sample of 276 self-identified adult allergy sufferers pooled from social media completed an online survey comprising 13 questions. The survey was fielded by a professional research organization (Lab42). The main outcome measures included the use of prescription and/or non-prescription allergy medication, and interactions with physician and/or pharmacist with respect to medication use. RESULTS: Of the respondents, 53% (146/276) indicated that they used both prescription and over-the-counter medication to manage their allergy symptoms. Of those who used prescription medication, 53% reported that they discussed their prescription medication in great detail with their physician when it was prescribed, while 42% spoke about it briefly. Following the initial prescription, few discussions about the prescription occur with the physician (45% indicate several discussions, 40% indicate one or two discussions, and 10% indicate no discussions). In most cases (~75% of the time), allergy prescription refills did not require a doctor visit with patients obtaining refills through phone calls to the doctor's office or through the pharmacy. Two-thirds of patients (69%) report that they have discussed their prescription allergy medication with a pharmacist, with greater than half of respondents having discussed the use of the non-prescription medication with their doctor. CONCLUSION: Patients with diagnosed allergic rhinitis appear to be self-managing their condition with few interactions with their doctor about their allergy prescription. Interactions with a pharmacist about allergy medication (prescription and non-prescription) appear to be more common than interactions with a physician.

Consumption of a dietary portfolio of cholesterol lowering foods improves blood lipids without affecting concentrations of fat soluble compounds.

BACKGROUND: Consumption of a cholesterol lowering dietary portfolio including plant sterols (PS), viscous fibre, soy proteins and nuts for 6 months improves blood lipid profile. Plant sterols reduce blood cholesterol by inhibiting intestinal cholesterol absorption and concerns have been raised whether PS consumption reduces fat soluble vitamin absorption. OBJECTIVE: The objective was to determine effects of consumption of a cholesterol lowering dietary portfolio on circulating concentrations of PS and fat soluble vitamins. METHODS: Using a parallel design study, 351 hyperlipidemic participants from 4 centres across Canada were randomized to 1 of 3 groups. Participants followed dietary advice with control or portfolio diet. Participants on routine and intensive portfolio involved 2 and 7 clinic visits, respectively, over 6 months. RESULTS: No changes in plasma concentrations of α and γ tocopherol, lutein, lycopene and retinol, but decreased ß-carotene concentrations were observed with intensive (week 12: p = 0.045; week 24: p = 0.039) and routine (week 12: p = 0.031; week 24: p = 0.078) portfolio groups compared to control. However, cholesterol adjusted ß-carotene and fat soluble compound concentrations were not different compared to control. Plasma PS concentrations were increased with intensive (campesterol:p = 0.012; ß-sitosterol:p = 0.035) and routine (campesterol: p = 0.034; ß-sitosterol: p = 0.080) portfolio groups compared to control. Plasma cholesterol-adjusted campesterol and ß-sitosterol concentrations were negatively correlated (p < 0.001) with total and LDL-C levels. CONCLUSION: Results demonstrate that consuming a portfolio diet reduces serum total and LDL-C levels while increasing PS values, without altering fat soluble compounds concentrations. The extent of increments of PS with the current study are not deleterious and also maintaining optimum levels of fat soluble vitamins are of paramount necessity to maintain overall metabolism and health. Results indicate portfolio diet as one of the best options for CVD risk reduction. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00438425.

Effect of a dietary portfolio of cholesterol-lowering foods given at 2 levels of intensity of dietary advice on serum lipids in hyperlipidemia: a randomized controlled trial.

CONTEXT: Combining foods with recognized cholesterol-lowering properties (dietary portfolio) has proven highly effective in lowering serum cholesterol under metabolically controlled conditions. OBJECTIVE: To assess the effect of a dietary portfolio administered at 2 levels of intensity on percentage change in low-density lipoprotein cholesterol (LDL-C) among participants following self-selected diets. DESIGN, SETTING, AND PARTICIPANTS: A parallel-design study of 351 participants with hyperlipidemia from 4 participating academic centers across Canada (Quebec City, Toronto, Winnipeg, and Vancouver) randomized between June 25, 2007, and February 19, 2009, to 1 of 3 treatments lasting 6 months. INTERVENTION: Participants received dietary advice for 6 months on either a low-saturated fat therapeutic diet (control) or a dietary portfolio, for which counseling was delivered at different frequencies, that emphasized dietary incorporation of plant sterols, soy protein, viscous fibers, and nuts. Routine dietary portfolio involved 2 clinic visits over 6 months and intensive dietary portfolio involved 7 clinic visits over 6 months. MAIN OUTCOME MEASURES: Percentage change in serum LDL-C. RESULTS: In the modified intention-to-treat analysis of 345 participants, the overall attrition rate was not significantly different between treatments (18% for intensive dietary portfolio, 23% for routine dietary portfolio, and 26% for control; Fisher exact test, P = .33). The LDL-C reductions from an overall mean of 171 mg/dL (95% confidence interval [CI], 168-174 mg/dL) were -13.8% (95% CI, -17.2% to -10.3%; P < .001) or -26 mg/dL (95% CI, -31 to -21 mg/dL; P < .001) for the intensive dietary portfolio; -13.1% (95% CI, -16.7% to -9.5%; P < .001) or -24 mg/dL (95% CI, -30 to -19 mg/dL; P < .001) for the routine dietary portfolio; and -3.0% (95% CI, -6.1% to 0.1%; P = .06) or -8 mg/dL (95% CI, -13 to -3 mg/dL; P = .002) for the control diet. Percentage LDL-C reductions for each dietary portfolio were significantly more than the control diet (P < .001, respectively). The 2 dietary portfolio interventions did not differ significantly (P = .66). Among participants randomized to one of the dietary portfolio interventions, percentage reduction in LDL-C on the dietary portfolio was associated with dietary adherence (r = -0.34, n = 157, P < .001). CONCLUSION: Use of a dietary portfolio compared with the low-saturated fat dietary advice resulted in greater LDL-C lowering during 6 months of follow-up. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00438425.

Soy protein reduces serum cholesterol by both intrinsic and food displacement mechanisms.

The apparently smaller LDL cholesterol (LDL-C)-lowering effect of soy in recent studies has prompted the U.S. FDA to reexamine the heart health claim previously allowed for soy products. We therefore attempted to estimate the intrinsic and extrinsic (displacement) potential of soy in reducing LDL-C to determine whether the heart health claim for soy continues to be justified. The intrinsic effect of soy was derived from a meta-analysis using soy studies (20-133 g/d soy protein) included in the recent AHA Soy Advisory. The extrinsic effect of soy in displacing foods higher in saturated fat and cholesterol was estimated using predictive equations for LDL-C and NHANES III population survey data with the substitution of 13-58 g/d soy protein for animal protein foods. The meta-analysis of the AHA Soy Advisory data gave a mean LDL-C reduction of 0.17 mmol/L (n = 22; P < 0.0001) or 4.3% for soy, which was confirmed in 11 studies reporting balanced macronutrient profiles. The estimated displacement value of soy (13-58 g/d) using NHANES III population survey data was a 3.6-6.0% reduction in LDL-C due to displacement of saturated fats and cholesterol from animal foods. The LDL-C reduction attributable to the combined intrinsic and extrinsic effects of soy protein foods ranged from 7.9 to 10.3%. Thus, soy remains one of a few food components that reduces serum cholesterol (>4%) when added to the diet.