Ketogenic diet has a positive association with mental and emotional well-being in the general population.

OBJECTIVES: A ketogenic diet reduces pathologic stress and improves mood in neurodegenerative and neurodevelopmental disorders. However, the effects of a ketogenic diet for people from the general population have largely been unexplored. A ketogenic diet is increasingly used for weight loss. Research in healthy individuals primarily focuses on the physical implications of a ketogenic diet. It is important to understand the holistic effects of a ketogenic diet, not only the physiological but also the psychological effects, in non-clinical samples. The aim of this cross-sectional study with multiple cohorts was to investigate the association of a ketogenic diet with different aspects of mental health, including calmness, contentedness, alertness, cognitive and emotional stress, depression, anxiety, and loneliness, in a general healthy population. METHODS: Two online surveys were distributed: cohort 1 used Bond-Lader visual analog scales and Perceived Stress Scale (n = 147) and cohort 2 the Depression Anxiety Stress Scale and revised UCLA Loneliness Scale (n = 276). RESULTS: A ketogenic diet was associated with higher self-reported mental and emotional well-being behaviors, including calmness, contentedness, alertness, cognitive and emotional stress, depression, anxiety, and loneliness, compared with individuals on a non-specific diet in a general population. CONCLUSION: This research found that a ketogenic diet has potential psychological benefits in the general population.

Meaningful Change Thresholds and Fatigue Severity Points on Patient-Reported Outcomes by the Fatigue Symptoms and Impacts Questionnaire in Patients With Relapsing Multiple Sclerosis.

OBJECTIVES: The Fatigue Symptoms and Impacts Questionnaire-Relapsing Multiple Sclerosis (FSIQ-RMS) is a new content-valid, concise, and reliable 20-item patient-reported outcome measure to evaluate the symptoms and impacts of fatigue in patients with relapsing forms of multiple sclerosis. Analyses were performed to derive meaningful change thresholds (MCTs) on patient-reported outcomes as measured by FSIQ-RMS and generate receiver operating characteristic (ROC) curves to determine fatigue severity cut points at baseline and change in severity at post-baseline and supplement the anchor-based MCT results. METHODS: Analyses were based on data from the OPTIMUM trial (NCT02425644). An anchor-based approach using uncollapsed changes on the Patient Global Impression of Severity at week 108 were used to determine the MCT for only the FSIQ-RMS Symptoms domain; distribution-based MCT estimations were conducted using baseline FSIQ-RMS Impacts scores. ROC curves with calculation of area under the curve were used to identify the best cut point. RESULTS: Based on the evidence provided by the anchor-based analyses using the Patient Global Impression of Severity as an anchor for the FSIQ-RMS Symptoms domain, meaningful score changes for improvement and deterioration were -6.3 and 6.3, respectively. Meaningful score changes for the FSIQ-RMS Physical, Cognitive/Emotional, and Coping Impacts domains using distribution-based methods were 10.8, 8.4, and 9.8, respectively. These results are supported by the ROC analyses. CONCLUSIONS: Thresholds to support interpretation of the FSIQ-RMS, such as MCTs, can be used to determine and categorize patients who have experienced a meaningful change in their MS-related fatigue (eg, responder analyses) in future clinical research studies.

Bracing Adolescent Idiopathic Scoliosis (BASIS) study - night-time versus full-time bracing in adolescent idiopathic scoliosis: study protocol for a multicentre, randomized controlled trial.

Aims: Scoliosis is a lateral curvature of the spine with associated rotation, often causing distress due to appearance. For some curves, there is good evidence to support the use of a spinal brace, worn for 20 to 24 hours a day to minimize the curve, making it as straight as possible during growth, preventing progression. Compliance can be poor due to appearance and comfort. A night-time brace, worn for eight to 12 hours, can achieve higher levels of curve correction while patients are supine, and could be preferable for patients, but evidence of efficacy is limited. This is the protocol for a randomized controlled trial of 'full-time bracing' versus 'night-time bracing' in adolescent idiopathic scoliosis (AIS). Methods: UK paediatric spine clinics will recruit 780 participants aged ten to 15 years-old with AIS, Risser stage 0, 1, or 2, and curve size (Cobb angle) 20° to 40° with apex at or below T7. Patients are randomly allocated 1:1, to either full-time or night-time bracing. A qualitative sub-study will explore communication and experiences of families in terms of bracing and research. Patient and Public Involvement & Engagement informed study design and will assist with aspects of trial delivery and dissemination. Discussion: The primary outcome is 'treatment failure' (Cobb angle progression to 50° or more before skeletal maturity); skeletal maturity is at Risser stage 4 in females and 5 in males, or 'treatment success' (Cobb angle less than 50° at skeletal maturity). The comparison is on a non-inferiority basis (non-inferiority margin 11%). Participants are followed up every six months while in brace, and at one and two years after skeletal maturity. Secondary outcomes include the Scoliosis Research Society 22 questionnaire and measures of quality of life, psychological effects of bracing, adherence, anxiety and depression, sleep, satisfaction, and educational attainment. All data will be collected through the British Spine Registry.

Symptoms, impacts, and suitability of the Pulmonary Arterial Hypertension-Symptoms and Impact (PAH-SYMPACT™) questionnaire in patients with sarcoidosis-associated pulmonary hypertension (SAPH): a qualitative interview study.

BACKGROUND: Sarcoidosis-associated pulmonary hypertension (SAPH) is a prevalent and serious complication of sarcoidosis. No SAPH-specific self-report instruments for assessing SAPH symptoms and their impact on patients are available to date. This study sought to determine whether the Pulmonary Arterial Hypertension-Symptoms and Impact (PAH-SYMPACT™) questionnaire is suitable for use in patients with SAPH. METHODS: Patients diagnosed with SAPH participated in qualitative one-on-one telephone interviews to better understand SAPH symptoms and their impacts on patients' lives and to determine the appropriateness of the PAH-SYMPACT™ for use in patients with SAPH. The interviews comprised concept elicitation, completion of the PAH-SYMPACT™, and cognitive debriefing. Interview transcripts were analyzed by content analysis. RESULTS: Eleven patients with SAPH were interviewed between August 2019 and June 2020. In the concept elicitation, all 11 participants endorsed shortness of breath and nine participants (82%) rated it as their "most bothersome or severe" symptom. Impacts endorsed by all 11 participants were difficulty walking uphill or up stairs and difficulty in performing daily activities. Cognitive debriefing indicated that the PAH-SYMPACT™ items were relevant and understandable to most participants and reflected their experiences of SAPH. Participants indicated that no key symptoms or impacts of SAPH were missing. They also reported that the PAH-SYMPACT™ instructions and response options were clear, and that it would be feasible to complete the 11 symptom items and one oxygen use item as part of their daily schedule. CONCLUSIONS: This study suggests the PAH-SYMPACT™ is suitable for assessing symptoms and their impact in patients with SAPH. However, larger longitudinal studies are needed to confirm that it is fit for use in this patient population and that it can be used to reliably detect temporal changes in patients' symptom status. Trial registration Not applicable.

Symptoms, impacts, and suitability of the Pulmonary Arterial Hypertension - Symptoms and Impact (PAH-SYMPACT™) questionnaire in patients with chronic thromboembolic pulmonary hypertension (CTEPH): a qualitative interview study.

BACKGROUND: Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare form of pulmonary hypertension caused by blood clots and scar tissue in the blood vessels of the lungs. Health-related quality of life is often significantly impaired in patients with CTEPH. However, a better understanding of how CTEPH symptoms affect patients' lives is needed to optimally assess the impact of the disease and treatment. OBJECTIVES: This qualitative study aimed to better understand the symptoms of CTEPH and how they affect patients' lives, as well as to determine the appropriateness of the Pulmonary Arterial Hypertension - Symptoms and Impact (PAH-SYMPACT™) questionnaire for use in this patient population. METHODS: Adults diagnosed with CTEPH, recruited from two clinical sites in the US, participated in one-to-one qualitative telephone interviews. They described their experience of CTEPH symptoms and the impact these symptoms have on their lives. They also provided feedback on the comprehensibility and relevance of the PAH-SYMPACT™'s instructions, items, and response options. RESULTS: Participants (N = 12) had a mean age of 62.5 years. Two thirds were female and most (83%) had undergone pulmonary endarterectomy and/or balloon pulmonary angioplasty. The most frequently endorsed symptoms were shortness of breath (endorsed by all 12 participants), fatigue (11 participants), and lightheadedness (10 participants). All participants identified shortness of breath as an "extremely important" symptom, and seven participants rated fatigue as "extremely important." The most frequent impacts of CTEPH were on ability to walk quickly (endorsed by all 12 participants), ability to walk up inclines or stairs (11 participants), and ability to carry things (11 participants). The PAH-SYMPACT™ items were relevant to most participants and reflected their experience of CTEPH. All participants indicated that no important CTEPH symptoms were missing from the PAH-SYMPACT™. Overall, the instructions, items, and response options of the PAH-SYMPACT™ were clear and easy to understand. CONCLUSIONS: The symptoms and impacts experienced by patients with CTEPH align with items included in the PAH-SYMPACT™. The PAH-SYMPACT™ appears to be fit for purpose for assessing disease status in patients with CTEPH.

Burden of pulmonary arterial hypertension in England: retrospective HES database analysis.

BACKGROUND: The clinical and economic burden of pulmonary arterial hypertension (PAH) is poorly understood outside the United States. This retrospective database study describes the characteristics of patients with PAH in England, including their healthcare resource utilisation (HCRU) and associated costs. METHODS: Data from 1 April 2012 to 31 March 2018 were obtained from the National Health Service (NHS) Digital Hospital Episode Statistics database, which provides full coverage of patient events occurring in NHS England hospitals. An adult patient cohort was defined using an algorithm incorporating pulmonary hypertension (PH) diagnosis codes, PAH-associated procedures, PH specialist centre visits and PAH-specific medications. HCRU included inpatient admissions, outpatient visits and Accident and Emergency (A&E) attendances. Associated costs, calculated using national tariffs inflation-adjusted to 2017, did not include PAH-specific drugs on the High Cost Drugs list. RESULTS: The analysis cohort included 2527 patients (68.4% female; 63.6% aged ⩾50 years). Mean annual HCRU rates ranged from 2.9 to 3.2 for admissions (21-25% of patients had ⩾5 admissions), 9.4-10.3 for outpatient visits and 0.8-0.9 for A&E attendances. Costs from 2013 to 2017 totalled £43.2M (£33.9M admissions, £8.3M outpatient visits and £0.9M A&E attendances). From 2013 to 2017, mean cost per patient decreased 13% (from £4400 to £3833) for admissions and 13% (from £1031 to £896) for outpatient visits, but increased 52% (from £81 to £123) for A&E attendances. CONCLUSION: PAH incurs a heavy economic burden on a per-patient basis, highlighting the need for improved treatment strategies able to reduce disease progression and hospitalisations.The reviews of this paper are available via the supplemental material section.

Paediatric spinal trauma presenting to a UK major trauma centre.

PURPOSE: Paediatric spine trauma is uncommon and is managed differently from adults due to the anatomical differences of the paediatric spine. The paediatric spine is less ossified, with lax ligaments and a higher fulcrum in the c-spine which results in a different pattern of injuries. The aim of this study is to provide a contemporary audit of paediatric spinal trauma. METHODS: A retrospective review was conducted using the Trauma and Audit Research Network database at a major trauma centre (2011-2018). All patients < 18 years old with a spine injury underwent case note and radiology review. RESULTS: A total of 72 patients (37, 51.4% male with an average age of 13.3 (± 5.9) years old) were identified. The most common mechanism of injury was road traffic collisions (n = 39, 54.2%). The most common sporting cause was motocross accidents (n = 6, 8.3%), and a further 6 (8.3%) patients had a suspected inflicted injury. Eight patients (11.1%) sustained a spinal cord injury. Twenty-seven (37.5%) patients underwent surgical intervention to treat their spinal injury. CONCLUSION: This series demonstrates the profile of injury mechanisms causing paediatric spinal injuries. Paediatric spine injuries continue to have the potential for lifelong disability and require careful, specialist management. This series also highlights certain causes such as motocross accidents and suspected inflicted injury which are more frequent than expected and raise potential public health concerns.

Evidence synthesis in pulmonary arterial hypertension: a systematic review and critical appraisal.

BACKGROUND: The clinical landscape of pulmonary arterial hypertension (PAH) has evolved in terms of disease definition and classification, trial designs, available therapies and treatment strategies as well as clinical guidelines. This study critically appraises published evidence synthesis studies, i.e. meta-analyses (MA) and network-meta-analyses (NMA), to better understand their quality, validity and discuss the impact of the findings from these studies on current decision-making in PAH. METHODS: A systematic literature review to identify MA/NMA studies considering approved and available therapies for treatment of PAH was conducted. Embase, Medline and the Cochrane's Database of Systematic Reviews were searched from database inception to April 22, 2020, supplemented by searches in health technology assessment websites. The International Society for Pharmacoeconomics and Outcomes Research (ISPOR) checklist covering six domains (relevance, credibility, analysis, reporting quality and transparency, interpretation and conflict of interest) was selected for appraisal of the included MA/NMA studies. RESULTS: Fifty-two full publications (36 MAs, 15 NMAs, and 1 MA/NMA) in PAH met the inclusion criteria. The majority of studies were of low quality, with none of the studies being scored as 'strong' across all checklist domains. Key limitations included the lack of a clearly defined, relevant decision problem, shortcomings in assessing and addressing between-study heterogeneity, and an incomplete or misleading interpretation of results. CONCLUSIONS: This is the first critical appraisal of published MA/NMA studies in PAH, suggesting low quality and validity of published evidence synthesis studies in this therapeutic area. Besides the need for direct treatment comparisons assessed in long-term randomized controlled trials, future efforts in evidence synthesis in PAH should improve analysis quality and scrutiny in order to meaningfully address challenges arising from an evolving therapeutic landscape.

Future changes in the trading of virtual water.

Water stressed regions rely heavily on the import of water-intensive goods to offset insufficient food production driven by socioeconomic and environmental factors. The water embedded in these traded commodities, virtual water, has received increasing interest in the scientific community. However, comprehensive future projections of virtual water trading remain absent. Here we show, for the first time, changes over the 21st century in the amount of various water types required to meet international agricultural demands. Accounting for evolution in socioeconomic and climatic conditions, we estimate future interregional virtual water trading and find trading of renewable water sources may triple by 2100 while nonrenewable groundwater trading may at least double. Basins in North America, and the La Plata and Nile Rivers are found to contribute extensively to virtual water exports, while much of Africa, India, and the Middle East relies heavily on virtual water imports by the end of the century.

Identification of a pulmonary arterial hypertension (PAH) patient cohort and study of its burden of illness in Programme de Médicalisation des Systèmes d'information (PMSI).

OBJECTIVES: Define a French PAH cohort using an evidence-based algorithm and describe its burden of disease in terms of healthcare resource use and costs. METHODS: A retrospective database analysis was performed using the French national hospital discharge database (PMSI-MCO, 2012-2016). The main criteria used to define the PAH patient cohort were the PH ICD-10 codes (I27.0 or I27.2), a visit to an expert referral centre, a right heart catheterisation procedure and/or a prescription of a PAH specific drug. Hospital visits were split based on the length of stay. 0-day length of stay visits were labelled outpatient visits while all others were labelled inpatient visits. RESULTS: A cohort of 2173 patients diagnosed with PAH was defined. These patients had 26,944 hospital visits over the study period. Approximately 63% of patients were female and mean age at index date was 58 years old. Inpatient visits represented 52% of total hospital events with an average between 2.2 and 2.3 inpatient visits per year per patient. The average number of outpatient visits per year increased from 1.4 to 2.5 (2012 to 2016). The average cost per patient in 2016 for inpatient visits was equal to €10,256 while outpatient visits cost was equal to €1899. The 20% of patients associated with the highest costs accounted for approximately 60% of total costs in each year. CONCLUSIONS: There is a high hospital economic burden of PAH in France. The high level of resource use and costs is mainly attributable to inpatient visits and has remained stable throughout the time period studied.

Wearable Sensors for COVID-19: A Call to Action to Harness Our Digital Infrastructure for Remote Patient Monitoring and Virtual Assessments.

The COVID-19 pandemic has brought into sharp focus the need to harness and leverage our digital infrastructure for remote patient monitoring. As current viral tests and vaccines are slow to emerge, we see a need for more robust disease detection and monitoring of individual and population health, which could be aided by wearable sensors. While the utility of this technology has been used to correlate physiological metrics to daily living and human performance, the translation of such technology toward predicting the incidence of COVID-19 remains a necessity. When used in conjunction with predictive platforms, users of wearable devices could be alerted when changes in their metrics match those associated with COVID-19. Anonymous data localized to regions such as neighborhoods or zip codes could provide public health officials and researchers a valuable tool to track and mitigate the spread of the virus, particularly during a second wave. Identifiable data, for example remote monitoring of cohorts (family, businesses, and facilities) associated with individuals diagnosed with COVID-19, can provide valuable data such as acceleration of transmission and symptom onset. This manuscript describes clinically relevant physiological metrics which can be measured from commercial devices today and highlights their role in tracking the health, stability, and recovery of COVID-19+ individuals and front-line workers. Our goal disseminating from this paper is to initiate a call to action among front-line workers and engineers toward developing digital health platforms for monitoring and managing this pandemic.

Life cycle assessment of decentralized greywater treatment systems with reuse at different scales in cold regions.

Decentralized source-separated wastewater treatment systems offer an attractive alternative to conventional centralized wastewater treatment systems in various regions, yet few system analyses specifically address decentralized greywater treatment over different scales. Here we present a comparative life cycle assessment (LCA) and focus on global warming potential (GWP), eutrophication potential (EUP) and human health - carcinogenic potential (HHCP) of decentralized greywater management systems at different scales for a hypothetical community in a cold (winter) region. To provide a comparison between nature-based and engineered greywater treatment solutions, constructed wetlands (CW) and membrane bioreactors (MBR), respectively, were investigated at three different scales; community (3500 person equivalent [PE]), neighborhood (350 PE) and household (a single household [up to 5 PE]). Conventional centralized wastewater treatment was also included as a business-as-usual (BAU) scenario. In the MBR scenarios, greywater reuse was also considered for multiple non-potable applications due to its high-quality effluent and subsurface garden irrigation was considered for reuse in the CW scenarios. For scenarios with the same treatment technology, larger scales reduced GWP, EUP and HHCP up to 57 kg CO2-eq.PE-1.y-1, 0.2 kg N-eq.PE-1.y-1 and 5.3E-6 CTUh.PE-1.y-1, respectively, despite the need for more extensive wastewater networks. The CW scenarios at community and neighborhood scales outperformed the MBR and BAU scenarios for greywater treatment, while the community-scale MBR scenario may be environmentally preferable when large amount of greywater can be reused. The scale of decentralized systems, quantity of water reused and mix of electricity technologies all played important roles in determining GWP, EUP and HHCP values.

Clostridium difficile Infection-Daily Symptoms (CDI-DaySyms™) questionnaire: psychometric characteristics and responder thresholds.

BACKGROUND: The purpose of the current study was to determine the final content validation, psychometric characteristics, clinically meaningful improvement, and responder thresholds of the Clostridium difficile infection (CDI)-Daily Symptoms (CDI-DaySyms™) patient-reported outcome (PRO) questionnaire. METHODS: This validation study was part of two phase III studies (NCT01987895 and NCT01983683) conducted in patients with mild-to-moderate or severe CDI who completed the CDI-DaySyms™ daily throughout the treatment period. The questionnaire was evaluated in three stages: final PRO item content validation (Stage I); psychometric evaluation of reliability and construct validity (Stage II); and determination of clinically meaningful improvement and responder thresholds using distribution-based methods (Stage III). RESULTS: The analysis included 168 patients. Most patients were female and Caucasian with mild-to-moderate CDI. The mean age was 57.1 years. Initial item analysis supported by confirmatory factor analysis demonstrated the relevance of 10 items grouped into three distinct domains (Diarrhea Symptoms, Abdominal Symptoms, and Systemic/Other Symptoms). Domain scores demonstrated acceptable internal consistency and test-retest reliability, were sensitive to change, and correlated in expected directions with other relevant symptom and disease-severity measures. Responder thresholds were defined as score changes of - 1.00, - 0.80, and - 0.70 in the Diarrhea Symptoms, Abdominal Symptoms, and Systemic/Other Symptoms domains, respectively. CONCLUSIONS: The CDI-DaySyms™ is a valid measure of patient-reported CDI symptoms, with good measurement properties, which supports its utility as an endpoint in clinical studies. Further studies confirming responder thresholds based on anchor-based methods are required. TRIAL REGISTRATION: NCT01987895 , registered November 20, 2013; NCT01983683 , registered November 14, 2013.

On the accuracy of crop production and water requirement calculations: Process-based crop modeling at daily, semi-weekly, and weekly time steps for integrated assessments.

Integrated models are crucial for evaluation of the complex interactions and trade-offs among policy choices and socioeconomic, technical, and environmental processes. The use of process-based crop models as components of integrated models offers the possibility of significantly improving such analyses; however, challenges exist in terms of simulation scales and degree of integration. Therefore, this study evaluates the applicability of coarser-than-daily simulation time steps to simulate long-term crop yields in integrated models, and the impacts of aggregated weather input data on yields for a water-driven crop-process model based on the FAO AquaCrop model. We ran simulations at daily, semi-weekly, and weekly time steps in conjunction with coarser temporal resolution (weekly) weather input data for three crops in four locations over ten years to represent a range of crops and growing environments. Simulation results were compared to a reference case from AquaCrop using daily time step with daily weather data. Model skill for simulating crop biomass and yield and water demands was assessed statistically for each of these four hypothetical farms. Visual representations were also used to compare simulated soil moisture, crop canopy, and actual evapotranspiration values. Weekly climate data led to overestimation of crop biomass and yield regardless of the time step used. High agreements and low bias errors were realized for crop production and water estimates at daily and semi-weekly time steps, whereas weekly simulations showed poorer performance. Longer time steps intensified the impacts of weather input data aggregation, and overestimation became more pronounced with increases in time step length. The findings have important implications for integrated assessments that couple crop models with other socioeconomic, environmental, or hydrologic models, and provide guidance for modelers involved in interdisciplinary agricultural and water resources applications, including policy assessments, evaluation of water and food security, and resource use and efficiency under climate change.

Elicitation of health state utilities associated with the mode of administration of drugs acting on the prostacyclin pathway in pulmonary arterial hypertension.

INTRODUCTION: Pulmonary arterial hypertension (PAH) is a rare, incurable disease associated with decreased life expectancy and a marked impact on quality of life (QoL). There are three classes of drugs available for treatment: endothelin receptor antagonists (ERA), drugs acting on nitric oxide pathway (riociguat and phosphodiesterase type 5 inhibitors [PDE5i]), and drugs acting on prostacyclin pathway. The latter have widely different modes of administration - continuous intravenous infusion, continuous subcutaneous infusion, inhaled, and oral - each associated with variable treatment burden, and implications for health economic assessment. This study aimed to establish utility values associated with different modes of administration of drugs acting on the prostacyclin pathway for use in economic evaluations of PAH treatments. METHODS: A UK general public sample completed the EQ-5D-5L and valued four health states in time trade-off interviews. The health states drafted from literature and interviews with PAH experts (n=3) contained identical descriptions of PAH and ERA/PDE5i treatment, but differed in description of administration including oral (tablets), inhaled (nebulizer), continuous subcutaneous infusion, and continuous intravenous infusion. RESULTS: A total of 150 participants (63% female; mean age 37 years) completed interviews. Utilities are presented as values between 0 and 1, with 0 representing the state of being dead and 1 representing being in full health. The mean (SD) utility for oral health state was 0.85 (0.16), while all other health states were significantly lower at 0.74 (0.27) for inhaled (p=0.001), 0.59 (0.31) for subcutaneous (p<0.001) and 0.54 (0.32) for intravenous (p<0.001), indicating that there are disutilities (negative differences) associated with non-oral health states. Disutilities were -0.11 for inhaled, -0.26 for subcutaneous, and -0.31 for intravenous administration. CONCLUSION: The results demonstrate quantifiable QoL differences between modes of administration of drugs acting on the prostacyclin pathway. QoL burden should be considered for economic evaluation of drugs for PAH treatment.

Monochloramine loss mechanisms and dissolved organic matter characterization in stormwater.

Monochloramine (NH2Cl) is widely used for secondary disinfection by water utilities. However, Edmonton field stormwater sampling results have shown that NH2Cl, because of its long-lasting property, can cause stormwater contamination through outdoor potable water uses during the summer season. To protect water sources, it is important to understand NH2Cl dissipation mechanisms in stormwater. Natural organic matter (NOM) is the dominant species that contributes to NH2Cl decay in stormwater. In this research, it is proposed that NOM reacted with both NH2Cl and free chlorine through rapid and long-term reactions during NH2Cl dissipation. Based on this assumption, a kinetic model was developed and applied to estimate the NH2Cl decay in real stormwater samples, and the modeling results matched experimental data well under all the conditions. Further, the stormwater dissolved organic matter (SWDOM) collected from different neighborhoods was analyzed by Fourier transform infrared (FTIR) and fluorescence excitation-emission matrix (EEM) techniques. Humic substances were found to be dominant in SWDOM, and the samples from different neighborhoods had similar organic constituents. After reaction with excess NH2Cl, 25%-41% SWDOM fluorophores converted to inorganic components, while most of DOM remained in organic form. Humic substances as the major components in SWDON, are the dominant precursors of disinfection by-products in chloramination. Therefore, the potential reaction products of stormwater humic substances with NH2Cl should also be of concern. This research provided a useful method to estimate the NH2Cl dissipation in stormwater, and the methodology can also be applied for stormwater NH2Cl decay studies in other cities. Further, it is believed the SWDOM analysis in this research will contribute to future studies of NH2Cl NOM reaction mechanisms in both storm sewers and drinking water distribution systems.

Field data analysis of active chlorine-containing stormwater samples.

Many municipalities in Canada and all over the world use chloramination for drinking water secondary disinfection to avoid DBPs formation from conventional chlorination. However, the long-lasting monochloramine (NH2Cl) disinfectant can pose a significant risk to aquatic life through its introduction into municipal storm sewer systems and thus fresh water sources by residential, commercial, and industrial water uses. To establish general total active chlorine (TAC) concentrations in discharges from storm sewers, the TAC concentration was measured in stormwater samples in Edmonton, Alberta, Canada, during the summers of 2015 and 2016 under both dry and wet weather conditions. The field-sampling results showed TAC concentration variations from 0.02 to 0.77 mg/L in summer 2015, which exceeds the discharge effluent limit of 0.02 mg/L. As compared to 2015, the TAC concentrations were significantly lower during the summer 2016 (0-0.24 mg/L), for which it is believed that the higher precipitation during summer 2016 reduced outdoor tap water uses. Since many other cities also use chloramines as disinfectants for drinking water disinfection, the TAC analysis from Edmonton may prove useful for other regions as well. Other physicochemical and biological characteristics of stormwater and storm sewer biofilm samples were also analyzed, and no significant difference was found during these two years. Higher density of AOB and NOB detected in the storm sewer biofilm of residential areas - as compared with other areas - generally correlated to high concentrations of ammonium and nitrite in this region in both of the two years, and they may have contributed to the TAC decay in the storm sewers. The NH2Cl decay laboratory experiments illustrate that dissolved organic carbon (DOC) concentration is the dominant factor in determining the NH2Cl decay rate in stormwater samples. The high DOC concentrations detected from a downstream industrial sampling location may contribute to a high stormwater NH2Cl decay rate in this area.

Monochloramine dissipation in storm sewer systems: field testing and model development.

Monochloramine (NH2Cl), as the dominant disinfectant in drinking water chloramination, can provide long-term disinfection in distribution systems. However, NH2Cl can also be discharged into storm sewer systems and cause stormwater contamination through outdoor tap water uses. In storm sewer systems, NH2Cl dissipation can occur by three pathways: (i) auto-decomposition, (ii) chemical reaction with stormwater components, and (iii) biological dissipation. In this research, a field NH2Cl dissipation test was conducted with continuous tap water discharge into a storm sewer. The results showed a fast decrease of NH2Cl concentration from the discharge point to the sampling point at the beginning of the discharge period, while the rate of decrease decreased as time passed. Based on the various pathways involved in NH2Cl decay and the field testing results, a kinetic model was developed. To describe the variation of the NH2Cl dissipation rates during the field testing, a time coefficient fT was introduced, and the relationship between fT and time was determined. After calibration through the fT coefficient, the kinetic model described the field NH2Cl dissipation process well. The model developed in this research can assist in the regulation of tap water outdoor discharge and contribute to the protection of the aquatic environment.

Health state utilities associated with attributes of weekly injection devices for treatment of type 2 diabetes.

BACKGROUND: Glucagon-like peptide-1 (GLP-1) receptor agonists are often recommended as part of combination therapy for type 2 diabetes when oral medication does not result in sufficient glycemic control. Several GLP-1 receptor agonists are available as weekly injections. These medications vary in their injection delivery systems, and these differences could impact quality of life and treatment preference. The purpose of this study was to estimate utilities associated with attributes of injection delivery systems for weekly GLP-1 therapies. METHODS: Participants with type 2 diabetes in the UK valued health states in time trade-off interviews. The health states (drafted based on literature, device instructions for use, and clinician interviews) had identical descriptions of type 2 diabetes, but differed in description of the treatment process. One health state described oral treatment, while six others described oral treatment plus a weekly injection. The injection health states varied in three aspects of the treatment administration process: requirements for reconstituting the medication (i.e., mixing the medication prior to the injection), waiting during medication preparation, and needle handling. Every participant valued all seven health states. RESULTS: A total of 209 participants completed interviews (57.4% male; mean age = 60.4y). The mean utility of the oral treatment health state was 0.89. All injection health states had significantly (p < 0.01) lower utilities ranging from 0.86 to 0.88. Differences among health state utilities suggest that each administration requirement had a small but measureable disutility: -0.004 (reconstitution), -0.004 (needle handling), -0.010 (reconstitution, needle handling), and -0.020 (reconstitution, waiting, needle handling). CONCLUSIONS: Findings suggest it is feasible to use the TTO method to quantify preferences among injection treatment processes. It may be useful to incorporate these utility differences into cost-utility models comparing weekly injectable treatments for patients with type 2 diabetes.