Chemical aspects of peracetic acid based wastewater disinfection

Peracetic acid (PAA) has been studied for wastewater disinfection  applications for some 30 years and has been shown to be an effective disinfectant against many indicator microbes, including bacteria, viruses, and protozoa. One of the key advantages compared to, e.g., chlorine is the lack of harmful disinfection by-products. In this paper a pilot-scale study of PAA-based disinfection is presented. Indicator microbes (E. coli, total coliforms and coliphage viruses) as well as chemical parameters (pH, oxidation-reduction potential (ORP), chemical and biochemical oxygen  demand (COD and BOD), and residual PAA and hydrogen peroxide) were studied. The main aim of this investigation was to study how these  selected chemical parameters change during PAA treatment. Based on the results, disinfection was efficient at C·t values of 15 to 30 (mg·min)/l which equals to a PAA dose of 1.5 to 2 mg/l and a contact time of 10 to 15 min. In this concentration area changes in pH, COD and BOD were negligible. However, hydrogen peroxide residues may interfere with COD   measurements and apparent COD can be higher than the calculated   theoretical oxygen demand (ThOD). Additionally PAA or hydrogen peroxide residues interfere with the BOD test resulting in BOD values that are too  low. Residual PAA and ORP were found to correlate with remaining amounts of bacteria.Keywords: tertiary wastewater disinfection, peracetic acid, total coliform, E. coli, coliphage

Opportunities and challenges of behavior change support systems for enhancing habit formation:a qualitative study

Abstract The formation of healthy habits is considered to play a fundamental role in health behavior change. A variety of studies on Health Behavior Change Support Systems (HBCSS) have been conducted recently, in which individuals use such systems to influence their own attitudes or behaviors to achieve their personal goals. However, comparatively much less research has been devoted to studying how the users of these systems form habits with the help of HBCSS, or to understanding how to design these systems to support habit formation. Objective: The objective of this article is to study HBCSS user experiences regarding habit formation through an intervention study targeted at establishing a healthier lifestyle. This study also aims to map habit formation stages, as suggested by Lally and Gardner, with the Persuasive System Design (PSD) model. The application domain is the prevention of metabolic syndrome, in which 5% weight loss can significantly reduce the prevalence of the syndrome. Methods: This study employs a web-based HBCSS named Onnikka, a lifestyle intervention designed for the prevention of metabolic syndrome for participants who are at risk of developing a metabolic syndrome or are already suffering from it. The system under investigation was designed according to the principles of the PSD model and Behavior Change Support System framework. Lally and Gardner’s research on the stages of habit formation were used to study the extent to which the Onnikka system was able to enhance the development of new habits. A total of 43 Onnikka users were interviewed for this study during and after a 52-week intervention period. The research approach employed here was hermeneutics, which leans ontologically toward the social construction of reality, gained through language, consciousness, and shared meaning. In addition, the system’s login data and participants’ weight measurements were utilized to build an interpretation of the results. Results: The findings of this study suggest that IT habits appear to have a strong linkage with use adherence, whereas lifestyle habits did not seem to be directly related to the 5% weight loss among study participants. Moreover, habit formation stages provide a possible explanation for why self-monitoring, reminders, and tunneling were perceived as especially valuable features in this study. Conclusions: For sustainable weight management, holistic e-health interventions are required, and the PSD model offers a practical approach for designing and developing them. Recognizing the stages of habit formation provides additional valuable guidance for designing systems that help shape an individual’s habits

Low eating self-efficacy is associated with unfavorable eating behavior tendencies among individuals with overweight and obesity

Abstract Success in long-term weight management depends partly on psychological and behavioral aspects. Understanding the links between psychological factors and eating behavior tendencies is needed to develop more effective weight management methods. This population-based cross-sectional study examined whether eating self-efficacy (ESE) is associated with cognitive restraint (CR), uncontrolled eating (UE), emotional eating (EE), and binge eating (BE). The hypothesis was that individuals with low ESE have more unfavorable eating behavior tendencies than individuals with high ESE. Participants were classified as low ESE and high ESE by the Weight-Related Self-Efficacy questionnaire (WEL) median cut-off point. Eating behavior tendencies were assessed with Three Factor Eating Questionnaire R-18 and Binge Eating Scale, and additionally, by the number of difficulties in weight management. The difficulties were low CR, high UE, high EE, and moderate or severe BE. Five hundred and thirty-two volunteers with overweight and obesity were included in the study. Participants with low ESE had lower CR (p < 0.03) and higher UE, EE, and BE (p < 0.001) than participants with high ESE. Thirty-nine percent of men with low ESE had at least two difficulties in successful weight control while this percentage was only 8% in men with high ESE. In women, the corresponding figures were 56% and 10%. The risk of low ESE was increased by high UE [OR 5.37 (95% CI 1.99–14.51)], high EE [OR 6.05 (95% CI 2.07–17.66)], or moderate or severe BE [OR 12.31 (95% CI 1.52–99.84)] in men, and by low CR [OR 5.19 (95% CI 2.22–12.18)], high UE [OR 7.20 (95% CI 2.41–19.22)], or high EE [OR 23.66 (95% CI 4.79–116.77)] in women. Low ESE was associated with unfavorable eating behavior tendencies and multiple concomitant difficulties in successful weight loss promotion. These eating behavior tendencies should be considered when counseling patients with overweight and obesity

Lifestyle counselling by persuasive information and communications technology reduces prevalence of metabolic syndrome in a dose–response manner:a randomized clinical trial (PrevMetSyn)

Abstract Objectives: The aim was to investigate whether lifestyle changes produced by persuasive Information and Communication Technology (ICT) counselling can lower the prevalence of metabolic syndrome (MetS). Methods: A total of 532 participants (20–60 years, body mass index 27–35 kg/m²) were randomly assigned to six arms according to counselling type (no, short-term, or intensive) with or without ICT intervention. In this report the prevalence of MetS and its components were compared between no-ICT group and ICT group. Moreover, the frequency of the web information system usage was analysed for the number of logins, responses to weekly messages, and other record variables. Results: The ICT group had significantly lower proportion of MetS (33.7% vs. 45.3%, p = .022) than the no-ICT group at 2-year follow-up. In mixed model, the ICT group had lower prevalence of MetS than no-ICT group (OR 0.50, 95%CI 0.27–0.90) after intervention. The tertile with the highest utilization had 71% lower prevalence of MetS compared with the lowest utilization tertile or the no-ICT group. Conclusions: Web-based ICT is able to reduce the prevalence of MetS. In addition, higher utilization of the web information system is associated with a greater decrease in the prevalence of MetS.Key messages Our internet health behaviour change support system based on persuasive design and cognitive behaviour therapy markedly reduces metabolic syndrome in overweight/obese subjects. As a stand-alone tool it may save healthcare personnel resources as it is suitable at a low cost for both obese/overweight patients and the public at large

Ceramide stearic to palmitic acid ratio predicts incident diabetes

Aims/hypothesis Ceramide lipids have a role in the development of insulin resistance, diabetes and risk of cardiovascular disease. Here we investigated four ceramides and their ratios to find the best predictors of incident diabetes. Methods A validated mass-spectrometric method was applied to measure Cer(d18:1/16:0), Cer(d18:1/18:0), Cer(d18:1/24:0) and Cer(d18:1/24:1) from serum or plasma samples. These ceramides were analysed in a population-based risk factor study (FINRISK 2002, n = 8045), in a cohort of participants undergoing elective coronary angiography for suspected stable angina pectoris (Western Norway Coronary Angiography Cohort [WECAC], n = 3344) and in an intervention trial investigating improved methods of lifestyle modification for individuals at high risk of the metabolic syndrome (Prevent Metabolic Syndrome [PrevMetSyn], n = 371). Diabetes risk score models were developed to estimate the 10 year risk of incident diabetes. Results Analysis in FINRISK 2002 showed that the Cer(d18:1/18:0)/Cer(d18:1/16:0) ceramide ratio was predictive of incident diabetes (HR per SD 2.23, 95% CI 2.05, 2.42), and remained significant after adjustment for several risk factors, including BMI, fasting glucose and HbA1c (HR 1.34, 95% CI 1.14, 1.57). The finding was validated in the WECAC study (unadjusted HR 1.81, 95% CI 1.53, 2.14; adjusted HR 1.39, 95% CI 1.16, 1.66). In the intervention trial, the ceramide ratio and diabetes risk scores significantly decreased in individuals who had 5% or more weight loss. Conclusions/interpretation The Cer(d18:1/18:0)/Cer(d18:1/16:0) ratio is an independent predictive biomarker for incident diabetes, and may be modulated by lifestyle intervention

Ceramide stearic to palmitic acid ratio predicts incident diabetes

Abstract Aims/hypothesis: A validated mass-spectrometric method was applied to measure Cer(d18:1/16:0), Cer(d18:1/18:0), Cer(d18:1/24:0) and Cer(d18:1/24:1) from serum or plasma samples. These ceramides were analysed in a population-based risk factor study (FINRISK 2002, n = 8045), in a cohort of participants undergoing elective coronary angiography for suspected stable angina pectoris (Western Norway Coronary Angiography Cohort [WECAC], n = 3344) and in an intervention trial investigating improved methods of lifestyle modification for individuals at high risk of the metabolic syndrome (Prevent Metabolic Syndrome [PrevMetSyn], n = 371). Diabetes risk score models were developed to estimate the 10 year risk of incident diabetes. Methods: A validated mass-spectrometric method was applied to measure Cer(d18:1/16:0), Cer(d18:1/18:0), Cer(d18:1/24:0) and Cer(d18:1/24:1) from serum or plasma samples. These ceramides were analysed in a population-based risk factor study (FINRISK 2002, n = 8045), in a cohort of participants undergoing elective coronary angiography for suspected stable angina pectoris (Western Norway Coronary Angiography Cohort [WECAC], n = 3344) and in an intervention trial investigating improved methods of lifestyle modification for individuals at high risk of the metabolic syndrome (Prevent Metabolic Syndrome [PrevMetSyn], n = 371). Diabetes risk score models were developed to estimate the 10 year risk of incident diabetes. Results: Analysis in FINRISK 2002 showed that the Cer(d18:1/18:0)/Cer(d18:1/16:0) ceramide ratio was predictive of incident diabetes (HR per SD 2.23, 95% CI 2.05, 2.42), and remained significant after adjustment for several risk factors, including BMI, fasting glucose and HbA1c (HR 1.34, 95% CI 1.14, 1.57). The finding was validated in the WECAC study (unadjusted HR 1.81, 95% CI 1.53, 2.14; adjusted HR 1.39, 95% CI 1.16, 1.66). In the intervention trial, the ceramide ratio and diabetes risk scores significantly decreased in individuals who had 5% or more weight loss. Conclusions/interpretation: The Cer(d18:1/18:0)/Cer(d18:1/16:0) ratio is an independent predictive biomarker for incident diabetes, and may be modulated by lifestyle intervention