Sustainable drainage systems (SuDS) are nature-based methods of managing urban stormwater runoff. Although they are widely used, some SuDS, such as highway filter drains (HFDs), are understudied with ...respect to sizing and performance. For the first time, we developed an analytical probabilistic model (APM) that can be used to design and estimate the hydrologic performance of HFDs. Unlike the conventionally used design-storm based or continuous simulation approaches, our APM can directly calculate the runoff capture ratios of HFDs using closed-form analytical equations. Validation of the APM presented here shows that it is robust and reliable. The relative differences between the APM-estimated and continuous simulation-determined runoff capture ratios for all the simulated design cases are less than 8.5%.
Understanding the water consumption patterns within a specific population informs development of increasingly accurate, spatially specific exposure and/or risk assessment of waterborne infection. The ...current study examined the consumption patterns of private well users in Ontario while considering potentially influential underlying sociodemographics, household characteristics, and experiential factors. A province‐wide online survey was circulated between May and August 2018 (n = 1,162). Overall, 81.5% of respondents reported daily well water consumption (i.e., tap water). Results indicate a mean daily well water consumption rate of 1,132 mL/day (SD = 649 mL/day) among well water consumers. Gender was significantly associated with well water consumption, with higher consumption rates found among female respondents. The experience of acute gastrointestinal illness (AGI) symptoms or diagnosis in the past 12 months did not impact the volume of water consumed, suggesting that experiencing previous AGI does not decrease consumption volumes, and therefore exposure over time. Significantly higher rates of well water consumption were found among respondents who reported previous testing or ongoing water treatment. Approximately 45.5% of survey respondents who stated that they do not consume well water selected bottled water as their primary household drinking water supply. Bottled water consumption was also not associated with previous AGI experiences. Findings will inform future quantitative microbial risk assessments associated with private well water use by providing spatially and demographically specific estimates of well water consumption.
Worldwide, Indigenous peoples are leading the revitalization of their/our cultures through the restoration of ecosystems in which they are embedded, including in response to increasing “megafires.” ...Concurrently, growing Indigenous‐led movements are calling for governments to implement Indigenous rights, titles and treaties, and many settler‐colonial governments are committing to reconciliation with Indigenous peoples and to implementing the United Nations Declaration on the Rights of Indigenous Peoples. Yet, despite growing recognition that just and effective conservation is only possible through partnerships with, or led by, Indigenous peoples, decolonizing approaches to restoration have received insufficient attention. However, reconciliation will be incomplete without Indigenous‐led restoration of Indigenous lands, knowledges, and cultures. In this article, we introduce the concept of “walking on two legs” to guide restoration scientists and practitioners in advancing the interconnected processes of Indigenous‐led restoration and reconciliation in Indigenous territories. As an action‐oriented framework articulated by Secwépemc Elder Ronald E. Ignace, “walking on two legs” seeks to bring Indigenous knowledges into balance with western scientific knowledge in service of upholding an Indigenous stewardship ethic that is embedded in Indigenous ways of relating to land and embodies principles of respect, reciprocity, and responsibility. Grounding this discussion in the context of fire‐adapted ecosystems of western Canada and unceded and traditional Secwépemc territory, Secwepemcúl̓ecw, we argue that walking on two legs, along with principles of reconciliation, offers a pathway to uphold respectful relationships with Indigenous peoples, knowledges, and territories through Indigenous‐led restoration.
Colloids are ubiquitous in groundwater systems, and understanding their behavior is of critical importance as they can pose a threat to human and environmental health. Extensive research has been ...conducted to model colloid behavior in fractures leading to the development of a number of analytical solutions, albeit for single fractures. However, the application of these analytical solutions at the network scale has not yet been established; thus, fracture networks are modeled using numerical techniques that are verified in single fractures first. Time domain random walk (TDRW) is a Lagrangian‐based approach originally designed to simulate solute transport in single fractures considering advection, dispersion, and matrix diffusion. The present study develops a modified TDRW approach (MTDRW) to consider colloid‐specific transport mechanisms based on an analytical solution describing colloid behavior in single fractures. The MTDRW approach was validated through simulating the behavior of (i) monodisperse colloids in a synthetic, single fracture with and without matrix diffusion; (ii) polydisperse colloids in a synthetic, single fracture with impermeable matrix; and (iii) monodisperse colloids in a synthetic impermeable fracture network. In all three cases, the MTDRW approach replicated the results of analytical solutions in single fractures and the semianalytical solution in fracture networks. The MTDRW approach is expected to enhance the reliability of colloid transport modeling due to its capacity to simulate the physiochemical heterogeneity across the network. This is required to (i) evaluate the aquifer vulnerability to colloid migration; (ii) predict the aquifer resilience under contamination events; and (iii) develop effective planning, management, and remediation strategies.
Key Points
A modified time domain random walk (MTDRW) approach was developed to model colloid transport in fractures
This MTDRW approach can model colloid‐specific transport and retention mechanisms at the single‐fracture and fracture‐network scales
The chemical and physical heterogeneity within the aquifer can be captured using the developed approach
In Ontario, Canada, Indigenous communities experience some of the province's worst drinking water, with issues ranging from deteriorating water quality to regulatory problems and lack of support. ...When water is known, or suspected, to be unsafe for human consumption, communities are placed under a Drinking Water Advisory. Between 2004 and 2013, approximately 70% of all on-reserve communities in Ontario were under at least one Drinking Water Advisory. Despite the widespread impact of Drinking Water Advisories on health and wellbeing, little is known about First Nation individuals' perceptions and experiences living with a Drinking Water Advisory. This study presents information shared by members of a community who have lived with Boil Water Advisories on and off for many years, and a long-term Boil Water Advisory since 2017. The goal of this paper is to unpack and explore the Boil Water Advisories from the perspective of community members and provide considerations for current and future Boil Water Advisory management.
Methodological choices were driven by the principles of community-based participatory research. Two data collection methodologies were employed: hard copy surveys and interviews.
Forty-four individuals (19.5%) completed a survey. Eight Elders and 16 key informants participated in 20 interviews. Respondents expressed varying degrees of uncertainty regarding protective actions to take while under a Boil Water Advisory. Further, 79% of men but only 46% of women indicated they always adhere to the Boil Water Advisory. Knowledge gaps that could lead to risky behaviours were also identified. Finally, Boil Water Advisories were demonstrated to have physical, financial, and time impacts on the majority of respondents.
A direct outcome was the identification of a critical need to reinforce best practices for health protection through community education and outreach. More broadly, Chief and Council were able to use the findings to successfully advocate for improved drinking water for the community. Additionally, benefits of participatory research and community ownership include enhanced local research capacity, and increased awareness of, and desire for, research to inform decisions.
Understanding the behavior of colloids in groundwater is critical as some are pathogenic while others may facilitate or inhibit the transport of dissolved contaminants. Colloid behavior in saturated ...fractured aquifers is governed by the physical and chemical properties of the groundwater-particle-fracture system. The interaction between these properties is nonlinear, and there is a need for a mathematical model describing the relationship between them to advance the mechanistic understanding of colloid transport in fractures and facilitate modeling in fractured environments. This paper coupled genetic programming and linear regression within a multigene genetic programming framework to develop a robust mathematical model describing the relationship between colloid retention in fractures and the physical and chemical parameters that describe the system. The data employed for model development and validation were collected from a series of 75 laboratory-scale colloid tracer experiments conducted under a range of conditions in three laboratory-induced discrete dolomite fractures and their epoxy replicas. The model sufficiently reproduced the observed data with coefficients of determination (R
) of 0.92 and 0.80 for model development and validation, respectively. A cross-validation demonstrated the model generality to 86% of the observed data. A variance-based global sensitivity analysis confirmed that attachment is the primary retention mechanism in the systems employed in this work. The model developed in this study provides a tool describing colloid retention in factures, which furthers the understanding of groundwater-particle-fracture system conditions contributing to the retention of colloids and can aid in the design of groundwater remediation strategies and development of groundwater management plans.
Triage and redirection of patients to alternative care providers is one tool used to overcome the growing issue of crowding in emergency departments (EDs). Electronic patient self-triage (eTriage) ...may reduce waiting times and required face-to-face contact. There are limited studies into its efficacy, accuracy and validity in an ED setting.
The aim of this study was to assess the agreement and validity of eTriage with a reference standard of nurse face-to-face triage. A secondary aim was to assess the ability of both systems to predict high and low acuity outcomes.
This was a retrospective study conducted over 8 months in two UK hospitals. Inclusion criteria were all ambulatory patients aged ≥18. All patients completed an eTriage and nurse-led triage using the Manchester Triage System (MTS).
During the study period, 43 788 adult patients attended one of the two ED sites and 26 757 used eTriage. A total of 1424 patient episodes had no recorded MTS and were excluded from the study leaving 25 333 paired triages for the final cohort. Agreement between eTriage and nurse triage was low with a weighted Kappa coefficient of 0.14 (95% CI, 0.14-0.15) with an associated weak positive correlation (rs 0.321). Level of undertriage by eTriage compared with nurse triage was 10.1%, and overtriage was 59.2%. The sensitivity for prediction of high acuity outcomes was 88.5% (95% CI, 77.9-95.3%) for eTriage and 53.8% (95% CI 41.1-66.0%) for nurse MTS. The specificity for predicting low risk patients was 88.5% (95% CI, 87.4-89.5%) for eTriage and 80.6% (95% CI, 79.3-81.8%) for nurse MTS.
Agreement and correlation of eTriage with the reference standard of nurse MTS was low; patients using eTriage tended to over triage when compared to the triage nurse. eTriage had a higher sensitivity for high acuity presentations and demonstrated similar specificity for low acuity presentations when compared to triage nurse MTS. Further work is necessary to validate eTriage as a potential tool for safe redirection of ED attenders to alternative care providers.
The synthesis and characterization of silver nanoparticles (AgNPs) using natural pigments from plants as reducing agents is presented in this study. The natural pigments were extracted from Alfalfa ...leaves. The reduction reaction was investigated by UV–Vis and FTIR analyses. The synthesized AgNPs were characterized by UV–Vis, XRD, TEM, and DLS. UV–Vis analysis revealed that AgNPs were produced with a persistent plasmonic absorption peak at about 418 nm accompanied by consumption of pigments. The reduction is suggested to occur, mainly, by chlorophyll
a
and carotenes. Characterization revealed pure synthesized AgNPs with an average particle size of 25 nm. In an interesting novel experiment, the progress of reduction reaction was traced at the interface between reacting phases under UV illumination making use of fluorescence of both chlorophylls and formed Ag nano-clusters (AgNCs). The enrollment of chlorophylls in reduction was suggested depending on FTIR and fluorescence analyses. The synthesized AgNPs possessed a superior antimicrobial activity towards
Staphylococcus aureus
ATCC 29213; 24.0 mm ZOI, followed by
Escherichia coli
ATCC 25922; 17.0 mm ZOI. In addition, AgNPs were a strong antifungal agent against
Candida albicans
ATCC 10231; 26.0 mm ZOI.
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