AbstractDrinking water advisories (DWAs) are a major issue facing many First Nations communities across Canada. This paper analyzes drinking water system data matched to DWA data using a ...probabilistic neural network (PNN) model to find key factors that influence the occurrence, frequency, duration, and cause of DWAs. First, for all data across Canada and subsequently for a number of data sets for individual provinces, the analyses were completed using an ensembles approach of running the same data set multiple times (in this case, five) to ensure that factors identified were representative of the entire data set and not just the training set. The results were compared with those from previous studies that used data mining techniques. Accuracies above 74% were achieved and key factors influencing each of the models were identified. The PNN models are a practical and powerful diagnostic tool for identifying key system attributes influencing DWAs, which can then be used to develop effective targeted solutions to mitigate the core issues that result in DWAs. These types of models can be used in other applications to identify influential factors and guide decision makers.
Providing safe drinking water continues to be a challenge in Canadian First Nations communities. In 2011, in Ontario and British Columbia, only 45 percent and 51 percent of 143 and 160 First Nations ...had water systems with a fully trained certified operator, respectively. The objective of this research was to investigate the issues of operator training, retention, and job satisfaction through semi-structured interviews and surveys of water system operators in Ontario and British Columbia. Operators reported the lack of funding for operation and maintenance, and a lack of support from band council as challenges in performing their jobs. Of those who reported being unsatisfied with their position, wages, hours of work, and lack of funding or support were cited as primary reasons.
Risk assessment methodologies, specifically water safety plans (WSPs), provide a water operator with a greater awareness of the drinking water system and the hazards that may occur. This brings key ...issues to the forefront and promotes a proactive approach to drinking water safety. This paper identifies the challenges in completing a WSP and evaluates the robustness of procedures. Experts knowledgeable in drinking water treatment were asked to complete Alberta’s Drinking Water Safety Plan template for a hypothetical community. Findings from use of a condensed version of the WSP are also described, and the resulting risk scores obtained from both methodologies are compared. A high degree of variability between experts’ responses was observed from both; however, trends between responses show that the condensed WSP makes it easier to compare hazards relative to each other, to determine key risk areas that warrant more attention.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Maintaining acceptable drinking water quality is a challenge in Canadian First Nations communities, resulting in many residents experiencing frequent drinking water advisories (DWAs). Detailed ...information about drinking water systems on reserves was combined with 11 years of advisory data to consolidate existing data sets and to understand historical trends. Patterns related to the frequency, duration and causes of advisories are summarized. The results show that the total number of DWAs has increased over the last decade despite recent attention, policy renewal and funding commitments. The frequency and duration of DWAs vary according to location, source type, system size and operator certification. Facilities relying on surface water have a higher likelihood of experiencing DWAs, and systems without fully trained operators are more likely to experience long-lasting DWAs. Findings indicate the need exists to maintain an up-to-date record of First Nations system information to close existing data gaps.
An innovative device for enhancing particle settling, referred to as the bottom grid structure (BGS), was tested in the forebay of an urban stormwater detention pond in two design variants. Results ...showed that compared to the simulated bare pond bottom (i.e., a reference condition), the BGSs collected more sediments during a three-month test period and also captured and retained some very fine particles (<32 μm) even under high flows. The improvements of particle removal rates expressed in multiples of removals for the bare bottom were 3.6, 7.3, and 11.2, respectively, for the particle size ranges 106 μm < D < 250 μm, 32 μm < D < 106 μm, and D < 32 μm. Because the BGS can retain much smaller particles than bare bottom sediment traps, the application of the BGS can be considered as equivalent to increasing the settling area of a particle removal facility about 5 to 60 times, depending on the size of settleable particles under consideration. This characteristic distinguishes the BGS from other sedimentation enhancement methods and makes it possible to treat stormwater with a wide particle size spectrum under high flow rates, with a relatively small footprint, and without using chemical settling aids or filtration.
Patients from opioid maintenance treatment (OMT) may taper off from opioids during rehab treatment. It is investigated whether this option improves treatment outcomes in particular for those patients ...who are affected by psychiatric or somatic comorbidity, or by social problems.
Multicenter study with 4 rehab units. Patient characteristics and treatment outcomes were collected retrospectively. There were n = 227 patients who were admitted to treatment while still receiving OMT, and n = 156 who were opioid free.
With regard to regular completion of rehab treatment, an interaction was observed between status at admission and diagnosis of affective, neurotic and anxiety disorders, and between status and previous rehab treatment experience. If admitted in an abstinent status, patients who had never entered rehab, and patients with affective or anxiety disorders showed decreased regular completion rates, while they showed increased completion rates if tapered off during treatment. There was no interaction between initial status and acute life crisis (release from prison, homelessness), somatic diagnoses, or number of stabilizing social factors.
Admission while still receiving opiate maintenance could be helpful for patients with psychiatric comorbidity and for patients who had previously been reluctant to enter rehab treatment.
A rational-based physical descriptive model (PDM) has been developed to predict the levels of Escherichia coli in water at a beach with dynamic conditions in the Greater Toronto Area (GTA), Ontario, ...Canada. Bacteria loadings in the water were affected not only by multiple physical factors (precipitation, discharge, wind, etc.), but also by cumulative effects, intensity, duration and timing of storm events. These may not be linearly related to the observed variations in bacteria levels, and are unlikely to be properly represented by a widely used multiple linear regression model. In order to account for these complex relationships, the amounts of precipitation and nearby creek discharge, the impact of various time-related factors, lag time between events and sample collection, and threshold for different parameters were used in determining bacteria levels. This new comprehensive PDM approach improved the accuracy of the E. coli level predictions in the studied beach water compared to the previously developed statistical predictive and presently used geometric mean models. In spite of the complexity and dynamic conditions at the studied beach, the PDM achieved 75% accuracy overall for the five case years examined.
Insights and Opportunities Murphy, Heather M.; Corston-Pine, Elliott; Post, Yvonne ...
International indigenous policy journal,
06/2015, Letnik:
6, Številka:
3
Journal Article
Recenzirano
Providing safe drinking water continues to be a challenge in Canadian First Nations communities. In 2011, in Ontario and British Columbia, only 45 percent and 51 percent of 143 and 160 First Nations ...had water systems with a fully trained certified operator, respectively. The objective of this research was to investigate the issues of operator training, retention, and job satisfaction through semi-structured interviews and surveys of water system operators in Ontario and British Columbia. Operators reported the lack of funding for operation and maintenance, and a lack of support from band council as challenges in performing their jobs. Of those who reported being unsatisfied with their position, wages, hours of work, and lack of funding or support were cited as primary reasons.
Patients with non–ST-segment elevation myocardial infarction and elevated high-sensitivity cardiac troponin levels often routinely undergo invasive coronary angiography (ICA), but many do not have ...obstructive coronary artery disease.
This study investigated whether cardiovascular magnetic resonance imaging (CMR) or computed tomographic angiography (CTA) may serve as a safe gatekeeper for ICA.
This randomized controlled trial (NCT01559467) in 207 patients (age 64 years; 62% male patients) with acute chest pain, elevated high-sensitivity cardiac troponin T levels (>14 ng/l), and inconclusive electrocardiogram compared a CMR- or CTA-first strategy with a control strategy of routine clinical care. Follow-up ICA was recommended when initial CMR or CTA suggested myocardial ischemia, infarction, or obstructive coronary artery disease (≥70% stenosis). Primary efficacy and secondary safety endpoints were referral to ICA during hospitalization and 1-year outcomes (major adverse cardiac events and complications), respectively.
The CMR- and CTA-first strategies reduced ICA compared with routine clinical care (87% p = 0.001, 66% p < 0.001, and 100%, respectively), with similar outcome (hazard ratio: CMR vs. routine, 0.78 95% confidence interval: 0.37 to 1.61; CTA vs. routine, 0.66 95% confidence interval: 0.31 to 1.42; and CMR vs. CTA, 1.19 95% confidence interval: 0.53 to 2.66). Obstructive coronary artery disease after ICA was found in 61% of patients in the routine clinical care arm, in 69% in the CMR-first arm (p = 0.308 vs. routine), and in 85% in the CTA-first arm (p = 0.006 vs. routine). In the non-CMR and non-CTA arms, follow-up CMR and CTA were performed in 67% and 13% of patients and led to a new diagnosis in 33% and 3%, respectively (p < 0.001).
A novel strategy of implementing CMR or CTA first in the diagnostic process in non–ST-segment elevation myocardial infarction is a safe gatekeeper for ICA.
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