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Purpose: The purposes of this research were to design a professional development (PD) initiative to introduce teachers to a pedagogical innovation—the Meaningful Physical Education (PE) approach—and to understand their experiences of the PD process. Method: Twelve PE teachers in Canada engaged in an ongoing PD initiative, designed around characteristics of effective PD, across two school years as they learned about and implemented Meaningful PE. Qualitative data were collected and analyzed. Findings: This research showed that teachers valued a community of practice and modeling when learning to implement Meaningful PE. While teachers were mostly favorable to the PD design, there were several tensions between ideal and realistic forms of PD. Discussion: This research offers support for several characteristics of effective PD to support teachers' implementation of a novel pedagogical approach and highlights the need to balance tensions in providing forms of PD that are both effective and practical. [ABSTRACT FROM AUTHOR]

New particle formation (NPF) substantially contributes to global cloud condensation nuclei (CCN), and their climate impacts. Individual NPF events are also thought to increase local CCN, cloud droplet number (CDN), and cloud albedo. High resolution simulations however go against the latter, showing that radiatively important stratiform clouds can experience a systematic and substantial decrease in CDN during and after NPF events. CDN drops because particles too small to act as CCN uptake condensable material, and stunt the growth of particles that would otherwise form droplets. Convective clouds however experience modest increases in CDN—consistent with established views on the NPF‐cloud link. Together, these results reshape our conceptual understanding of NPF impacts on clouds, as the newly discovered duality of responses would drive cloud systems in a fundamentally different manner than thought. Plain Language Summary: Most studies assume that cloud condensation nuclei (CCN) changes from new particle formation (NPF) events directly reflect cloud droplet number (CDN) responses in clouds and ignore the growth of pre‐existing particles and their contribution to CCN. High resolution state‐of‐the‐art simulations over Europe portray that while convective clouds experience modest increases in CDN, the radiatively important stratiform clouds may present a systematic and substantial decrease in droplet number during and after new particle formation (NPF) events. Consequently, it is evident that NPF exhibits a duality in response—which depending on the local conditions may vitally change the manner in which cloud systems may respond. Key Points: New particle formation (NPF) events have always been thought to increase the concentration of particles that form cloud droplets thus always lead to climate coolingΤhrough high resolution modeling it is showed that stratiform clouds influenced by NPF events may experience systematic reductions in droplet leading to local warming from reductions in cloud albedo, while droplet number is always enhanced in convective cloudsThese effects combined could bear important impacts on cloud properties and structure following NPF events [ABSTRACT FROM AUTHOR]

• Ratios of E-CHAIM model-to-RISR radar measured electron density are close to one at heights near F2 peak. • On average, E-CHAIM underestimates electron density at ionospheric topside and bottomside by ∼ 20 % • E-CHAIM underestimations are strongest in summer and equinoctial nighttime at bottomside and in autumn nighttime at topside. In this study, predictions of the E-CHAIM ionospheric model are compared with measurements by the incoherent scatter radars RISR at Resolute Bay, Canada, in the northern polar cap. Reasonable coverage was available for all seasons except winter for which no conclusions were drawn. It is shown that ratios of the model-to measured electron densities are close to unity in the central part of the F layer, around its peak. This is particularly evident for summer daytime. Distributions of the ratios are wider for other seasons indicating larger number of cases when the model underestimates or overestimates. E-CHAIM underestimates the electron density at ionospheric topside and bottomside by ∼ 10–20 %. At the bottomside, the underestimations are strongest in summer and equinoctial nighttime. At the topside, the underestimations are strongest in autumn nighttime. Model overestimations are noticeable in the middle part of the F layer during dawn hours in autumn. Overall, the model tends to not predict highest-observed peak electron densities and the largest-observed heights of the peak. [ABSTRACT FROM AUTHOR]

Key Takeaways: When confronted with the need for a utility or dedicated provider of water and wastewater services, the Indigenous peoples of Atlantic Canada viewed the issue from a perspective shaped by historical legacies. The Mi'kmaw and Wolastoqiyik (Wabanaki) nations founded the Atlantic First Nations Water Authority (AFNWA), one of Canada's first Indigenous‐owned water and wastewater services utilities. AFNWA adopted a full‐service, decentralized, hub‐and‐spoke model structure as being most consistent with First Nations concepts of ownership and values. [ABSTRACT FROM AUTHOR]

Livestock manure and organic agriculture wastes are an environmental challenge because they contribute to climate change by emitting greenhouse gases. Converting these organic wastes to biogas and bioenergy is a sustainable solution. Farmers, investors, and governmental departments involved in developing on-farm biogas projects need an informed decision-making process to fund such projects. Thus, estimating the required initial investment for a farm-based biogas plant is crucial. This study aims to develop two methods to estimate the cost of farm-based biogas projects, determine their economic viability, and predict the cost of each part of the plant and its related risks. A database for farm-based biogas projects in Canada and the USA was established and analyzed before developing the models. First, six mathematical models were developed using linear regression to predict the capital cost, engineering and design, operation and maintenance, gross revenue, and net profit using Monte Carlo simulation. Second, the probability of cost of components is calculated. The marginal error of cost prediction in initial modeling is about 7% in total, and the economic viability of a biogas plant for a farm housing less than 300 cows is questionable. [ABSTRACT FROM AUTHOR]

Increased use of phosphorus (P) fertilizers and detergents and intensified livestock production have more than doubled P inputs to human‐impacted watersheds over pre‐industrial levels. While P fertilizer use and manure application help to maximize crop yields, excess P is lost to runoff, leading to eutrophication of downstream waters. Excess P also accumulates across the landscape, leading to legacies that serve as long‐term sources of P to surface waters, even after inputs to the watershed are reduced. Here, we have developed, for the first time, a process‐based model, Exploration of Long‐tErM Nutrient Trajectories‐Phosphorus, designed to capture legacy P accumulation and depletion trajectories along the land‐aquatic continuum. To drive the model, we have developed a more than 100‐year trajectory of watershed P inputs to the Grand River Watershed (GRW), Canada's largest watershed draining directly to Lake Erie. Our results first show that net P inputs to the watershed approximately tripled between 1900 and the late‐1970s, when P surplus magnitudes peaked at approximately 15 kg ha−1 y−1. During this same period, stream P loads have increased more than fourfold, from 0.11 kg ha−1 y−1 in 1900 to 0.80 kg ha−1 y−1 in the 1970s. Since 1900, the GRW has served as a net P sink, with approximately 96% of net P inputs having been retained within the basin. Future simulations suggest that while 40% reductions in P loading in Lake Erie watersheds are possible under aggressive management scenarios, legacy P will continue to elevate P loads to Lake Erie for many decades to come. Plain Language Summary: Phosphorus is a major driver of algal blooms and water quality challenges throughout the Great Lakes region. Excess phosphorus from crop and livestock production is a particular problem in agricultural areas, and much of the phosphorus applied to the landscape is accumulating as legacy within our watersheds. We have developed a model demonstrating that watershed phosphorus legacies continue to degrade water quality over many decades and can make it difficult to meet water quality goals. Our modeling results show that we must take legacy phosphorus into account when setting policy goals for water quality improvement. Our results also show that better manure management can provide relatively fast improvements and should therefore be emphasized when implementing conservation measures. Key Points: More than 95% of surplus phosphorus has been retained within the watershed since 1900Legacy phosphorus is a major contributor to current watershed phosphorus loadsReducing manure handling losses can provide substantial reductions in watershed P loads [ABSTRACT FROM AUTHOR]

Grapevine anthracnose caused by Elsinoë ampelina is a serious threat in many vineyards, and its control requires repeated application of fungicides, usually on a calendar basis. A better understanding of the pathogen life cycle would help growers manage anthracnose more safely and effectively. After conducting a systematic literature search of grape anthracnose, we used the retrieved information and data to develop a mechanistic model based on systems analysis. The model simulates production and maturation of primary inoculum, infection caused by both primary and secondary conidia, and lesion formation and production of secondary inoculum. The model was validated for its ability to predict first seasonal onset of anthracnose lesions by using 8 years of data collected at Auckland, New Zealand, and disease progress during the season by using 3 years of data collected at Frelighsburg, Canada. Overall, the model provided accurate predictions of infection occurrence, with 0.96 accuracy, 0.91 sensitivity, and 0.97 specificity. The model also showed good accuracy for predicting disease progress, with a concordance correlation coefficient between observed and predicted disease severities of 0.92, a root mean square error of 0.14, and a coefficient of residual mass of 0.06. Although the model failed to predict 10 of 110 real infection periods, these missed infections led to only mild disease symptoms. We therefore conclude that the model is reliable and can be used to reduce the costs of anthracnose management by improving the timing of fungicide applications. [ABSTRACT FROM AUTHOR]

Background: Disease surveillance is central to the public health understanding of pertussis epidemiology. In Canada, public reporting practices have significantly changed over time, creating challenges in accurately characterizing pertussis epidemiology. Debate has emerged over whether pertussis resurged after the introduction of adsorbed pertussis vaccines (1981-1985), and if the incidence fell to its pre-1985 after the introduction of acellular pertussis vaccines (1997-1998). Here, we aim to assemble a unified picture of pertussis disease incidence in Canada.Methods: Using publicly available pertussis surveillance reports, we collected, analyzed and presented Canadian pertussis data for the period (1924-2015), encompassing the pre-vaccine era, introduction of vaccine, changes to vaccine technology, and the introduction of booster doses. Information on age began to be reported since 1952, but age reporting practices (full, partial or no ages) have evolved over time, and varied across provinces/territories. For those cases reported without age each year, we impute an age distribution by assuming it follows that of the age-reported cases.Results: Below the age of 20 years, the adjusted age-specific incidence from 1969 to 1988 is substantially higher than existing estimates. In children < 1 year, the incidence in some years was comparable to that during the 1988-1999 resurgence.Conclusions: The results presented here suggest that the surge in the average yearly incidence of pertussis that began in 1988 was weaker than previously inferred, and in contrary to the past findings, below age 5, the average yearly incidence of pertussis from 1999 to 2015 (when the incidence dropped again) has been lower than it was from 1969 to 1988. [ABSTRACT FROM AUTHOR]

Groundwater is the world's most important freshwater resource. Despite this importance, groundwater flow and interactions between groundwater and other parts of the hydrological cycle are often neglected or simplified in large‐scale hydrological models. One of the challenges in simulating groundwater flow and continental to global scales is the lack of consistent globally available hydrogeological data. These input data are needed for a more realistic physical representation of the groundwater system, enabling the simulation of groundwater head dynamics and lateral flows. A realistic representation of the subsurface is especially important as large‐scale hydrological models move to finer resolutions and aim to provide accurate and locally relevant hydrologic information everywhere. In this study, we aim at improving and extending on current available large‐scale data sets providing information of the subsurface. We present a detailed aquifer representation for the continental United States and Canada at hyper resolution (250 × 250 m). We integrate local hydrogeological information, including observations of aquifer layer thickness, conductivity, and vertical structure, to obtain representative aquifer parameter values applicable to the continental scale. The methods used are simple and can be expanded to other parts of the world. Hydrological simulations were performed using the integrated hydrological model ParFlow and demonstrated improved model performance when using the new aquifer parameterization. Our results support that more detailed and accurate aquifer parameterization will advance our understanding of the groundwater system at larger scales. Plain Language Summary: Groundwater is the largest available freshwater resource humans can use for drinking and growing food. It is stored beneath our feet in thick layers of sand or rock; we call these layers aquifers. For a realistic estimation of how much groundwater is stored and flows through these aquifers, detailed information on the properties of these layers is essential. However, this information is often missing, or not detailed enough, at the larger scales. In this study, we introduce a new method to obtain this detailed data by including information from observations and local‐scale studies what we upscaled to the continent of North America. We estimate aquifer parameters at very high spatial resolution over a large domain. These data were not available previously. We evaluate our newly obtained aquifer parameterization against other existing data sets and tested model sensitivity to different horizontal and vertical resolutions and conductivity values. We used the integrated hydrological model ParFlow. Our results show that estimates of water table depth improved using our new parameterization. The methods we introduce here can be used by other modelers looking to improve their aquifer parameterization. We hope that our study can be used as a road map towards improved and more detailed aquifer parameterization used in current large‐scale hydrological models. Key Points: We integrate local hydrogeological information into a continental‐scale aquifer parameterization for the continental United States and CanadaAquifer thickness and vertical structure are estimated at a level of detail not available beforeHydrological modeling confirmed accurate large‐scale aquifer parameterization will improve our understanding of the hydrological system [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic has significantly changed life and work patterns and reshaped the healthcare industry and public health strategies. It posed considerable challenges to public health emergency operations centers (PHEOCs). In this period, digital technologies such as modeling, simulation, visualization, and mapping (MSVM) emerged as vital tools in these centers. Despite their perceived importance, the potential and adaptation of digital tools in PHEOCs remain underexplored. This study investigated the application of MSVM in the PHEOCs during the pandemic in Canada using a questionnaire survey. The results show that digital tools, particularly visualization and mapping, are frequently used in PHEOCs. However, critical gaps, including data management issues, technical and capacity issues, and limitations in the policy-making sphere, still hinder the effective use of these tools. Key areas identified in this study for future investigation include collaboration, interoperability, and various supports for information sharing and capacity building.

• ASR expansion was suppressed and transferred to free or low stress directions. • Stress reduces the degradation of the modulus of elasticity. • ASR did not affect the peak shear strength of the low aspect ratio shear walls. • The Disturbed Stress Field Model provides a viable platform for implementing ASR constitutive models. Concrete nuclear structures have been identified as suffering from alkali aggregate reaction (AAR) in both Canada and the United States. Although much research effort has been directed toward understanding its effect on reinforced concrete structures, unresolved issues still remain. Among them are the effect of multiaxial stress states, commonly developed in nuclear structures, on the response of AAR-affected concrete; also of concern is the possible invalidity of conventional methods of analysis for structural assessment due to the induced anisotropy in the mechanical properties of concrete. The Canadian Nuclear Safety Commission initiated and funded an extensive study aimed to reveal the implications of concrete deterioration due to AAR on structural integrity, which included material and structural testing and modeling. This paper presents an overview of the entire research program and discusses the key results. [ABSTRACT FROM AUTHOR]

Arctic shelf seas are highly heterogeneous, making it difficult to accurately account for their role in regional and global air‐sea CO2 exchange budgets. Here we estimate the CO2 sink in the Canadian Arctic Archipelago (CAA) based on empirical relationships that account for spatiotemporal variations in the sea surface partial pressure of CO2 (pCO2sw) as a function of seasonal sea ice cycles. During the open water season from 2010 to 2016, the CAA acted as a net oceanic sink with an average CO2 flux of −7.7 ± 4 Tg C/year. This sink is significantly smaller than previous estimates for the CAA, emphasizing the importance of properly accounting for seasonal and spatial variability on Arctic shelves. Applying our analysis to a 37‐year record of sea ice conditions, we calculate an increase in the open water CO2 sink by ~150% (a trend of ~ −1.3 Tg C/decade), associated with sea ice loss and higher wind speeds. Plain Language Summary: Much of the carbon dioxide (CO2) humans put into the air ends up in the oceans. This is good because it slows down climate change but also bad because some creatures could be hurt by extra CO2. In the Arctic, it is hard to know how much CO2 is absorbed by the ocean, because the ocean is frozen for much of the year. In this paper, we try to figure out how much CO2 is going into the Canadian Arctic Archipelago—a shallow sea in northern Canada that is home to the famous Northwest Passage. We found that the amount of CO2 going into this sea is much lower than scientists thought before because they did not fully account for the ice. However, the amount of CO2 going into the sea each year is increasing, because sea ice is melting due to climate change. Key Points: The Canadian Arctic Archipelago acts as a net oceanic sink of CO2 during the open water season with an average uptake rate of 7.7 Tg C/yearAtmospheric CO2 uptake during the open water season has increased by 150% over 37 years due to sea ice loss and higher wind speedsEstimates of CO2 uptake on Arctic shelves must account for spatiotemporal variability in sea ice conditions [ABSTRACT FROM AUTHOR]

When glacial cycles occur above low‐permeability geologic formations, such as the shale and limestone units being considered for nuclear waste disposal in Canada, pressures may differ greatly from normal hydrostatic conditions. Although shale also often has the propensity to generate separate phase fluids like natural gas, it is largely uncertain how the processes that control this behavior might affect water pressure evolution during glacial loading cycles. Therefore, this study investigates the relationships among these system components via an example site that exhibits both a dramatic underpressure and potential evidence for gas phase methane in situ. A simple 1‐D representation of the site was constructed, and hydromechanical coupling during a glacial cycle was simulated with and without gas phase methane present. Results indicate that, while the presence of gas phase dampened the effects of the loading cycle due to its higher compressibility compared to water, it did not preclude underpressure development. Plain Language Summary: To protect water resources from contamination, many countries are planning to store nuclear waste underground within very tight layers of rock. To assess the safety of this strategy, we must understand how fluids might move through these rock layers over long periods of time. Anomalous pressures in low‐permeability rocks offer clues into long‐term flow processes, but natural gas complicates the pressure evolution. Therefore, in this study we performed mathematical simulations of water flow under the influence of glacial forces, with and without natural gas present. While gas phase somewhat counteracted the glacial effects due to its higher compressibility, underpressures similar to the measured values were still produced in both single‐phase and multiphase simulations. These results help to improve our understanding of the processes that might occur within the rocks at nuclear waste repository sites after they are built, thus protecting humans from potential contamination. Key Points: Vertical stresses from both ice weight and crustal flexure were incorporated in a 1‐D model of a proposed nuclear waste repository siteGas phase dampened the effects of glacial loading on simulated long‐term water pressure evolution at the proposed repository siteHydromechanical coupling could have led to underpressure in shale at the site, even if gas phase methane is assumed to be present in situ [ABSTRACT FROM AUTHOR]

The main objective of this study was to develop models for accurate prediction of municipal solid waste (MSW) generation and diversion based on demographic and socio-economic variables, with planned application of generating Canada-wide MSW inventories. Models were generated by mapping residential MSW quantities with socio-economic and demographic parameters of 220 municipalities in the province of Ontario, Canada. Two machine learning algorithms, namely decision trees and neural networks, were applied to build the models. Socio-economic variables were derived from Canadian Census data at regional and municipal levels. A data pre-processing and integration framework was developed in Matlab® computing software to generate datasets with sufficient data quantity and quality for modeling. Results showed that machine learning algorithms can be successfully used to generate waste models with good prediction performance. Neural network models had the best performance, describing 72% of variation in the data. The approach proposed in this study demonstrates the feasibility of creating tools that helps in regional waste planning by means of sourcing, pre-processing, integrating and modeling of publically available data from various sources. [ABSTRACT FROM AUTHOR]

The impact of climate change on forests is expected to vary globally and regionally. Canada’s Acadian Forest Region lies in the transition between the North American boreal and temperate forest biomes and may be particularly sensitive to changes in climate because many of its component species are currently at their southern or northern climatic range limits. Although some species may be lost, others may exhibit major productivity boosts—affecting the goods and services we derive from them. In this study, we use a well-established forest ecosystem simulation model, PICUS, to provide the first exploration of the impact of climate change on the composition and growth of the Acadian Forest Region for the period 2011 to 2100 under two radiative forcing scenarios, RCP 2.6 and RCP 8.5. In the short term (2011–2040), little to no changes in forest composition or growth were projected under either forcing scenario compared with current forest conditions (simulated for 1981–2010 baseline climate); however, by mid-century, PICUS projected increasing departures from the baseline simulations in both composition and growth, with the greatest changes occurring under RCP 8.5 during the late 21st century (2071–2100). Our study indicates that under rapid 21st century warming, Canada’s Acadian Forest Region will begin to lose its boreal character (i.e., “deborealize”) as key tree species fail to regenerate and survive. Furthermore, increased growth and establishment by warm-adapted, temperate tree species may be unable to keep pace with the rapid loss of boreal species. This potential “lag effect” may lead to a temporary decrease in forest growth and wood supply during the late 21st century. [ABSTRACT FROM AUTHOR]

Background: Approximately 2 in 3 US adults have prehypertension or hypertension that increases their risk of cardiovascular disease. Reducing sodium intake can decrease blood pressure and prevent hypertension. Approximately 9 in 10 Americans consume excess sodium (≥2300 mg/d). Voluntary sodium standards for commercially processed and prepared foods were established in North America, but their impact on sodium intake is unclear. Objective: We modelled the potential impact on US sodium intake of applying voluntary sodium standards for foods. Design: We used NHANES 2007-2010 data for 17,933 participants aged ≥1 y to model predicted US daily mean sodium intake and the prevalence of excess sodium intake with the use of the standards of the New York City's National Salt Reduction Initiative (NSRI) and Health Canada for commercially processed and prepared foods. The Food and Nutrient Database for Dietary Studies food codes corresponding to foods reported by NHANES participants were matched to NSRI and Health Canada food categories, and the published sales-weighted mean percent reductions were applied. Results: The US population aged ≥1 y could have reduced their usual daily mean sodium intake of 3417 mg by 698 mg (95% CI: 683, 714 mg) by applying NSRI 2014 targets and by 615 mg (95% CI: 597, 634 mg) by applying Health Canada's 2016 benchmarks. Significant reductions could have occurred, regardless of age, sex, race/ethnicity, income, education, or hypertension status, up to a mean reduction in sodium intake of 850 mg/d in men aged ≥19 y by applying NSRI targets. The proportion of adults aged ≥19 y who consume ≥2300 mg/d would decline from 88% (95% CI: 86%, 91%) to 71% (95% CI: 68%, 73%) by applying NSRI targets and to 74% (95% CI: 71%, 76%) by applying Health Canada benchmarks. Conclusion: If established sodium standards are applied to commercially processed and prepared foods, a significant reduction of US sodium intake could occur. [ABSTRACT FROM AUTHOR]

Northern peatlands store globally significant amounts of soil carbon that could be released to the atmosphere under drier conditions induced by climate change. We measured forest floor respiration (RFF) at hummocks and hollows in a treed boreal bog in Alberta, Canada and partitioned the flux into aboveground forest floor autotrophic, belowground forest floor autotrophic, belowground tree respiration, and heterotrophic respiration using a series of clipping and trenching experiments. These fluxes were compared to those measured at sites within the same bog where water-table (WT) was drawn down for 2 and 12 years. Experimental WT drawdown significantly increased RFF with greater increases at hummocks than hollows. Greater RFF was largely driven by increased autotrophic respiration driven by increased growth of trees and shrubs in response to drier conditions; heterotrophic respiration accounted for a declining proportion of RFF with time since drainage. Heterotrophic respiration was increased at hollows, suggesting that soil carbon may be lost from these sites in response to climate change induced drying. Overall, although WT drawdown increased RFF, the substantial contribution of autotrophic respiration to RFF suggests that peat carbon stocks are unlikely to be rapidly destabilized by drying conditions. [ABSTRACT FROM AUTHOR]

In the United States and Canada, Fusarium graminearum ( Fg ) is the predominant etiological agent of Fusarium head blight (FHB), an economically devastating fungal disease of wheat and other small grains . Besides yield losses, FHB leads to grain contamination with trichothecene mycotoxins that are harmful to plant, human, and livestock health. Three genetic North American populations of Fg , differing in their predominant trichothecene chemotype (i.e., NA1/15ADON, NA2/3ADON, and NA3/NX-2), have been identified. To improve our understanding of the newly discovered population NA3 and how population-level diversity influences FHB outcomes, we inoculated heads of the moderately resistant wheat cultivar Alsen with 15 representative strains from each population and evaluated disease progression, mycotoxin accumulation, and mycotoxin production per unit Fg biomass. Additionally, we evaluated population-specific differences in induced host defense responses. The NA3 population was significantly less aggressive than the NA1 and NA2 populations but posed a similar mycotoxigenic potential. Multiomics analyses revealed patterns in mycotoxin production per unit Fg biomass, expression of Fg aggressiveness-associated genes, and host defense responses that did not always correlate with the NA3-specific severity difference. Our comparative disease assay of NA3/NX-2 and admixed NA1/NX-2 strains indicated that the reduced NA3 aggressiveness is not due solely to the NX-2 chemotype. Notably, the NA1 and NA2 populations did not show a significant advantage over NA3 in perithecia production, a fitness-related trait. Together, our data highlight that the disease outcomes were not due to mycotoxin production or host defense alone, indicating that other virulence factors and/or host defense mechanisms are likely involved., Competing Interests: The author(s) declare no conflict of interest.

Purpose: In this paper, a novel modeling approach is applied to assess the unique transport characteristics of hydrophobic (bitumen containing) cohesive sediment for the Ells River, AB, Canada. The modeling offers a new way of treating the transport and fate of fine sediment in rivers and points to the importance of including a sediment entrapment process in the modeling of the Ells River sediment dynamics. Materials and methods: The modeling approach involves combining two existing models (RIVFLOC and MOBED). Using fine sediment transport parameters derived from laboratory flume experiments (e.g., settling velocity of sediment as a function of floc size and the critical shear stresses for deposition) and the calculated flow field from the MOBED model (using field survey data such as, cross-sectional geometry, river slope, grain size of bed material, and discharge), the RIVFLOC model is used to predict the transport characteristics (including entrapment) of the hydrophobic Ells River sediment. Results and discussion: The application of the connected RIVFLOC and MOBED models, demonstrated the unique hydrophobic sediment dynamics of the Ells River. The model showed no deposition (in the classical sense) of the hydrophobic sediment as the bed shear stresses, even at base flow, are well above the critical bed shear for deposition (flocculation is shown to occur, but its impact on settling is negligible given the high shear stresses). However, the model showed the possibility of fine sediment ingression into the river bed (interstitial voids) due to the entrapment process which is known to occur at bed shear stresses well above the critical shear stress for deposition. Conclusions: The salient features of RIVFLOC and MOBED models and their applications for understanding the transport and fate of unique hydrophobic fine sediments are presented. The models are shown to be useful for the understanding and projection of flow characteristics and sediment dynamics (including entrapment), and will be of benefit for the adaptive management of riverine monitoring programs given various flow scenarios including extreme events and climate change. [ABSTRACT FROM AUTHOR]

Since the advent of Global Navigation Satellite Systems, it has been possible to perform hydrographic survey reductions through the ellipsoid, which has the potential to simplify operations and improve bathymetric products. This technique requires a spatially continuous separation surface connecting chart datum (CD) to a geodetic ellipsoid. The Canadian Hydrographic Service (CHS), with support from the Canadian Geodetic Survey, has developed a new suite of such surfaces, termed Hydrographic Vertical Separations Surfaces, or HyVSEPs, for CD and seven tidal levels. They capture the spatial variability of the tidal datum and levels between tide gauges and offshore using semiempirical models coupling observations at tide stations with relative sea-level rise estimates, dynamic ocean model solutions, satellite altimetry, and a geoid model. HyVSEPs are available for all tidal waters of Canada, covering over seven million square kilometers of ocean and more than 200,000 kilometers of shoreline. This document provides an overview of the CHS's modeling approach, tools, methods, and procedures. The HyVSEP for CD defines the new hydrographic datum for the tidal waters of Canada. HyVSEPs for other tidal levels are fundamental for coastal studies, climate change adaptation and the definition of the Canadian shoreline and offshore boundaries. HyVSEPs for inland waters are not discussed. [ABSTRACT FROM AUTHOR]

Free sugars are a major source of calories in diets and contribute to the burden of many non-communicable diseases (NCDs). The World Health Organization (WHO) recommends reducing free sugars intake to less than 10% of total energy. This study aimed to estimate the number of diet-related NCD deaths which could be averted or delayed if Canadian adults were to reduce their calorie intake due to a systematic 20% reduction in the free sugars content in foods and beverages in Canada. We used the Preventable Risk Integrated ModEl (PRIME) to estimate the potential health impact. An estimated 6770 (95% UI 6184-7333) deaths due to diet-related NCDs could be averted or delayed, mostly from cardiovascular diseases (66.3%). This estimation would represent 7.5% of diet-related NCD deaths observed in 2019 in Canada. A 20% reduction in the free sugars content in foods and beverages would lead to a 3.2% reduction in calorie intake, yet an important number of diet-related NCD deaths could be averted or delayed through this strategy. Our findings can inform future policy decisions to support Canadians' free sugars intake reduction, such as proposing target levels for the free sugars content in key food categories.

Twelve instrument bundles were placed within two waste profiles as waste was placed in an operating landfill in Ste. Sophie, Quebec, Canada. The settlement data were simulated using a three-component model to account for primary or instantaneous compression, secondary compression or mechanical creep and biodegradation induced settlement. The regressed model parameters from the first waste layer were able to predict the settlement of the remaining four waste layers with good agreement. The model parameters were compared to values published in the literature. A MSW landfill scenario referenced in the literature was used to illustrate how the parameter values from the different studies predicted settlement. The parameters determined in this study and other studies with total waste heights between 15 and 60 m provided similar estimates of total settlement in the long term while the settlement rates and relative magnitudes of the three components varied. The parameters determined based on studies with total waste heights less than 15 m resulted in larger secondary compression indices and lower biodegradation induced settlements. When these were applied to a MSW landfill scenario with a total waste height of 30 m, the settlement was overestimated and provided unrealistic values. This study concludes that more field studies are needed to measure waste settlement during the filling stage of landfill operations and more field data are needed to assess different settlement models and their respective parameters. [ABSTRACT FROM AUTHOR]

Accurate estimates of spatiotemporally resolved Polychlorinated dibenzo-p-dioxins (PCDD/Fs, or dioxins) emissions are critical for understanding their environmental fate and associated health risks. In this study, by utilizing an empirical regression model for PCDD/Fs emissions, we developed a global emission inventory for 17 toxic PCDD/Fs congeners from 8 source sectors with a spatial resolution of 1° × 1° from 2002 to 2018. The results show that PCDD/Fs emissions decreased by 25.7 % (12.5 kg TEQ) between 2002 and 2018, mostly occurring in upper- and lower-middle income countries. Globally, open-burning processes, waste incineration, ferrous and nonferrous metal production sectors and heat and power generation were the major source sectors of PCDD/Fs. Spatially, high PCDD/Fs emissions were mainly identified in East and South Asia, Southeast Asia, and part of Sub-Saharan Africa. We find that the declining trend of dioxin emissions over the past decades terminated from the early 2010s due to increasing significance of wildfire induced emissions in the total emission. The PCDD/Fs emission inventory developed in the present study was verified by inputting the inventory as initial conditions into an atmospheric transport model, the Canadian Model for Environmental Transport of Organochlorine Pesticides (CanMETOP), to simulate PCDD/Fs concentrations in air and soil. The predicted concentrations were compared to field sampling data. The good agreement between the modeled and measured concentrations demonstrates the reliability of the inventory., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Abstract: The 23km-diameter well-preserved Haughton impact structure shows a rather unique combination of a positive magnetic anomaly with a negative gravity anomaly over the center of its central uplift. Using a new ground magnetic dataset and several modeling approaches, we investigate the properties and geometry of its central magnetized source. Our results confirm that a km-sized magnetic body with a narrow near-surface extension is necessary to account for the anomaly. Additional measurements of rock magnetic properties of samples of all lithologies encountered in and outside the crater show that the target sedimentary rocks and the vast majority of the Precambrian basement rocks cannot be the source of the magnetic anomaly. While in larger impact structures such magnetic anomalies are often explained by magmatic mafic intrusions or highly magnetic glass lenses in the impact melt rocks, we propose that impact-generated hydrothermal activity enhanced the magnetization of the highly-porous unmelted uplifted basement rocks. Such a process may be considered for the interpretation of the geophysical signature of planetary impact craters. [Copyright &y& Elsevier]

Background: This is the first study to have examined the effect of smoking bans on hospitalizations in the Atlantic Canadian socio-economic, cultural and climatic context. On June 1, 2003 Prince Edward Island (PEI) enacted a province-wide smoking ban in public places and workplaces. Changes in hospital admission rates for cardiovascular (acute myocardial infarction, angina, and stroke) and respiratory (chronic obstructive pulmonary disease and asthma) conditions were examined before and after the smoking ban. Methods: Crude annual and monthly admission rates for the above conditions were calculated from April 1, 1995 to December 31, 2008 in all PEI acute care hospitals. Autoregressive Integrated Moving Average time series models were used to test for changes in mean and trend of monthly admission rates for study conditions, control conditions and a control province after the comprehensive smoking ban. Age- and sex-based analyses were completed. Results: The mean rate of acute myocardial infarctions was reduced by 5.92 cases per 100,000 person-months (P = 0.04) immediately after the smoking ban. The trend of monthly angina admissions in men was reduced by −0.44 cases per 100,000 person-months (P = 0.01) in the 67 months after the smoking ban. All other cardiovascular and respiratory admission changes were non-significant. Conclusions: A comprehensive smoking ban in PEI reduced the overall mean number of acute myocardial infarction admissions and the trend of angina hospital admissions. [ABSTRACT FROM AUTHOR]

Abstract: We have studied the scaling behavior of compressional-wave velocity and density logs from an exploration borehole that extends down to about 700m depth in the Brunswick No. 6 mining area, Bathurst Mining Camp, Canada. Using statistical methods, vertical and horizontal scale lengths of heterogeneity were estimated. Vertical scale length estimates from the velocity, density and calculated acoustic impedance are 14m, 33m, and about 20m, respectively. Although the estimated scale length for the acoustic impedance implies a weak scattering environment, elastic finite difference modeling of seismic wave propagation in 2D heterogeneous media demonstrates that even this weak scattering medium can mask seismic signals from small, but yet economically feasible, massive sulfide deposits. Further analysis of the synthetic seismic data suggests that in the presence of heterogeneity, lenticular-shaped targets may only exhibit incomplete diffraction signals whereby the down-dip tails of these diffractions are mainly visible on the stacked sections. Therefore, identification of orebody generated diffractions is much easier on the unmigrated stacked sections than on migrated stacked sections. The numerical seismic modeling in 2D heterogeneous media indicates that in the presence of large horizontal, but small vertical scale lengths (structural anisotropy), identification of massive sulfide deposits is possible, but their delineation at depth requires detailed velocity modeling and processing algorithms which can handle the anisotropy. [Copyright &y& Elsevier]

Global anthropogenic and legacy mercury (Hg) emissions are the main sources of Arctic Hg contamination, primarily transported there via the atmosphere. This review summarizes the state of knowledge of the global anthropogenic sources of Hg emissions, and examines recent changes and source attribution of Hg transport and deposition to the Arctic using models. Estimated global anthropogenic Hg emissions to the atmosphere for 2015 were ~2220 Mg, ~20% higher than 2010. Global anthropogenic, legacy and geogenic Hg emissions were, respectively, responsible for 32%, 64% (wildfires: 6-10%) and 4% of the annual Arctic Hg deposition. Relative contributions to Arctic deposition of anthropogenic origin was dominated by sources in East Asia (32%), Commonwealth of Independent States (12%), and Africa (12%). Model results exhibit significant spatiotemporal variations in Arctic anthropogenic Hg deposition fluxes, driven by regional differences in Hg air transport routes, surface and precipitation uptake rates, and inter-seasonal differences in atmospheric circulation and deposition pathways. Model simulations reveal that changes in meteorology are having a profound impact on contemporary atmospheric Hg in the Arctic. Reversal of North Atlantic Oscillation phase from strongly negative in 2010 to positive in 2015, associated with lower temperature and more sea ice in the Canadian Arctic, Greenland and surrounding ocean, resulted in enhanced production of bromine species and Hg(0) oxidation and lower evasion of Hg(0) from ocean waters in 2015. This led to increased Hg(II) (and its deposition) and reduced Hg(0) air concentrations in these regions in line with High Arctic observations. However, combined changes in meteorology and anthropogenic emissions led to overall elevated modeled Arctic air Hg(0) levels in 2015 compared to 2010 contrary to observed declines at most monitoring sites, likely due to uncertainties in anthropogenic emission speciation, wildfire emissions and model representations of air-surface Hg fluxes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Crown Copyright © 2022. Published by Elsevier B.V. All rights reserved.)

Abstract: A hybrid model based on 3D deterministic Toutin’s model developed at the Canada Centre for Remote Sensing and taking full advantages of the image metadata was used to geometrically process WorldView-1 and -2 stereo images without in situ ground control points (GCPs) collection. Elevations were thus extracted and compared to 0.2-m accurate lidar elevation data to see the impact of no-GCP. Elevations linear errors with 68% confidence level (LE68) computed over bare surfaces were 2.6m and 2.1m for WorldView-1 and -2, respectively with small biases. The not-significant difference in LE68 (around 10–20cm), when compared to the solution using accurate GCPs, will offer strong advantages of no-control collection in operational conditions, mainly in remote and harsh environments or when cartographic or ground control data do not exist. [Copyright &y& Elsevier]

Abstract: This article presents the methodology and results of a hybrid numerical optimization study of a heating ceiling and wall hydronic radiant panel system in a typical residential building located in Quebec City, Canada. The comfort and energy consumption of the system are the two figures of merit that are considered in the multiobjective optimization analysis. The main design variables are the position and dimension of the panels, and the fluid inlet temperature. The hybrid numerical method features a 2D CFD model of a typical empty room, coupled with a semi-analytic radiant panel model specially developed for coupling with CFD. This strategy allows considering the real room geometry, while providing at the same time accurate temperature profiles of the radiant panels and detailed temperature and comfort data field in the room. The results show that there is no unique optimal solution but rather a family of optimal designs (Pareto fronts) for which the solutions are trade-offs between the two objectives. When adjusting correctly the fluid inlet temperature, it is also possible to achieve nearly Pareto optimal solutions, even when reducing the total panel surface by 66%. This means that the temperature control of the fluid is the most important parameter for maximizing comfort and minimizing energy consumption of hydronic heating radiant panels. [Copyright &y& Elsevier]

Two common approaches for studying trajectories of change are standard growth curve modeling (GCM) and latent class growth modeling (LCM) (Singer and Willett, Applied longitudinal data analysis. Modeling change and event occurrence. Oxford University Press, New York, ; Nagin, Group-based modeling of development. Harvard University Press, Cambridge, ). The objectives were to compare the results obtained using GCM and LCM in modeling trajectories of depressive symptoms in a sample of mothers of children with epilepsy; compare the methods in predicting average trajectory and individual trajectories, and; provide general guidelines for implementing these approaches. Findings from the two modeling strategies were different: GCM suggested a quadratic change in depressive symptoms over time. Addition of the time-varying covariate, family functioning, produced a final model that explained 25, 20, 31, and 18% of the residual intra-individual, as well as inter-individual variation in the intercept and slope (linear, quadratic), respectively. Results from the LCM suggested five distinct trajectories of depressive symptoms: low stable (30%) , sub- clinical (39%) , moderate decreasing (15%) , moderate increasing (9%) , and high decreasing (7%). Adding the family functioning variable resulted in a model that replaced the sub- clinical trajectory with borderline and moderate decreasing with high increasing. Both the GCM and LCM adequately described the average trajectory of maternal depressive symptoms with signed differences of 0.61 and 0.75 and −2.39 and −2.54 for the unconditional and conditional models, respectively. There was considerable variation in capturing individual trajectories. For approximately 14 and 9% of individuals, both models under and overestimated depression scores by at least five points. Although GCM and LCM perform equally well in predicting average and individual trajectories of change, they are used most efficiently under different circumstances. Where individuals are expected to share a homogeneous trajectory, GCM should be used; however, where individuals do not follow a common trajectory, LCM is more appropriate. [ABSTRACT FROM AUTHOR]

Abstract: Groundwater contamination by nitrate was investigated in an agricultural area in southern Quebec, Canada, where a municipal well is the local source of drinking water. A network of 38 piezometers was installed within the capture zone of the municipal well to monitor water table levels and nitrate concentrations in the aquifer. Nitrate concentrations were also measured in the municipal well. A Water flow and Nitrate transport Global Model (WNGM) was developed to simulate the impact of agricultural activities on nitrate concentrations in both the aquifer and municipal well. The WNGM first uses the Agriflux model to simulate vertical water and nitrate fluxes below the root zone for each of the seventy agricultural fields located within the capture zone of the municipal well. The WNGM then uses the HydroGeoSphere model to simulate three-dimensional variably-saturated groundwater flow and nitrate transport in the aquifer using water and nitrate fluxes computed with the Agriflux model as the top boundary conditions. The WNGM model was calibrated by reproducing water levels measured from 2005 to 2007 in the network of piezometers and nitrate concentrations measured in the municipal well from 1997 to 2007. The nitrate concentrations measured in the network of piezometers, however, showed greater variability than in the municipal well and could not be reproduced by the calibrated model. After calibration, the model was validated by successfully reproducing the decrease of nitrate concentrations observed in the municipal well in 2006 and 2007. Although it cannot predict nitrate concentrations in individual piezometers, the calibrated and validated WNGM can be used to assess the impact of changes in agricultural practices on global nitrate concentrations in the aquifer and in the municipal well. [Copyright &y& Elsevier]

Abstract: Gilbert Bay on the southeast coast of Labrador is the site of the first Marine Protected Area (MPA) established in the subarctic coastal zone of eastern Canada. The MPA was created to conserve a genetically distinctive population of Atlantic cod, Gadus morhua. This article presents results from a study of the interannual variability in atmospheric and physical oceanographic characteristics of Gilbert Bay over the period 1949–2006. We describe seasonal and interannual variability of the atmospheric parameters at the sea surface in the bay. The interannual variability of the atmosphere in the Gilbert Bay region is related to the North Atlantic Oscillation (NAO) and a recent warming trend in the local climate of coastal Labrador. The related changes in seawater temperature, salinity and sea-ice thickness in winter are simulated with a one-dimensional water column model, the General Ocean Turbulence Model (GOTM). A warming Gilbert Bay ecosystem would be favorable for cod growth, but reduced sea-ice formation during the winter months increases the danger of traveling across the bay by snowmobile. [Copyright &y& Elsevier]

In recent years, riparian buffers have become known as one of the most effective best management practices for nonpoint-source pollution. However, establishment of riparian buffer systems with respect to plant species and their position in the buffer zone has not been investigated due to lack of efficient evaluation methods for the analysis of water quality improvement with established riparian buffers. To solve this problem, the SWAT-REMM prototype version was developed by researchers in Canada. In the SWAT-REMM prototype version, many riparian-related input parameters are not directly read from the local input data. Thus, a SWAT-REMM enhancement was developed by improving three major limitations of the prototype version of SWAT-REMM: (1) riparian buffers at designated reaches in the watersheds, (2) riparian buffers using local soil properties at the riparian buffer zone along reaches, and (3) multiple weather stations in a larger-scale watershed. The enhanced SWAT-REMM version was applied to the Bonggok watershed in Korea. This study investigated riparian buffers with different widths (10 m, 5 m, and 1 m) along the slope. Total nitrogen reduction ranged from 14.8% to 54.0% in each catchment for 10 m widths. Total nitrogen reduction ranged from 6.9% to 31.6% in each catchment for 1 m widths. The reduction efficiency was not simply proportional to the width of buffers. This study evaluated the enhanced SWAT-REMM simulation of water quality improvement. Based on this research, the enhanced SWAT-REMM can be used to evaluate water quality improvement by riparian buffers at various watersheds worldwide using local data. In particular, simulation of riparian buffers at user-designated reaches in a watershed enables simulation of riparian buffers in watersheds experiencing frequent flooding where no riparian buffers can be established. It is expected that the enhanced SWAT-REMM can be used to determine economical and environmentally optimum riparian buffer scenarios. [ABSTRACT FROM AUTHOR]

Water temperature is a key physical habitat determinant in lotic ecosystems as it influences many physical, chemical, and biological properties of rivers. Hence, a good understanding of the thermal regime of rivers and river heat fluxes is essential for effective management of water and fisheries resources. This study dealt with the modelling of river water temperature using a deterministic model. This model calculated the different heat fluxes at the water surface and from the streambed using different hydrometeorological conditions. The water temperature model was applied on two watercourses of different sizes and thermal characteristics, but within a similar meteorological region, namely, the Little Southwest Miramichi River and Catamaran Brook (New Brunswick, Canada). The model was also applied using microclimate data, i.e. meteorological conditions within the river environment (1-2 m above the water surface), for a better estimation of river heat fluxes. Water temperatures at different depths within the riverbed were also used to estimate the streambed heat fluxes. Results showed that microclimate data were essential to get accurate estimates of the surface heat fluxes. Results also showed that for larger river systems, the surface heat fluxes were generally the dominant component of the heat budget with a correspondingly smaller contribution from the streambed. As watercourses became smaller and groundwater contribution more significant, the streambed contribution became important. For instance, approximately 80% of the heat fluxes occurred at the surface for Catamaran Brook (20% from the streambed) whereas the Little Southwest Miramichi River showed values closer to 90% (10% from the streambed). As was reported in previous studies, the solar radiation input dominated the contribution to the heat gain at 63% for Catamaran Brook and 89% for Little Southwest Miramichi River. [ABSTRACT FROM AUTHOR]

The Lucas critique has exposed the problem of the trade-off between changes in monetary policy and structural breaks in economic time series. The search for and characterization of such breaks has been a major econometric task ever since. We have developed an integral technique similar to CUSUM using an empirical model quantitatively linking the rate of inflation and unemployment to the change in the level of labour force in Canada. Inherently, our model belongs to the class of Phillips curve models, and the link between the involved variables is a linear one with all coefficients of individual and generalized models obtained by empirical calibration. To achieve the best LSQ fit between measured and predicted time series cumulative curves are used as a simplified version of the 1-D boundary elements (integral) method. The distance between the cumulative curves (in L² metrics) is very sensitive to structural breaks since it accumulates true differences and suppresses uncorrelated noise and systematic errors. Our previous model of inflation and unemployment in Canada is enhanced by the introduction of structural breaks and is validated by new data in the past and future. The most exiting finding is that the introduction of inflation targeting as a new monetary policy in 1991 resulted in a structural break manifested in a lowered rate of price inflation accompanied by a substantial fall in the rate of unemployment. Therefore, the new monetary policy in Canada is a win-win one. [ABSTRACT FROM AUTHOR]

Abstract: The Devonian Redwater reef is being assessed for geological storage of CO2 for the Heartland Area Redwater CO2 Storage Project (HARP). The reef complex is one of the largest Devonian reefs in the Western Canadian Sedimentary Basin. It has an area of about 600 km2 and lies at depth of approximately 1000 m, and has a thickness of up to 300 m. The reef is of Devonian age and is made up of the Lower, Middle and Upper Leduc Formations. It is underlain by the Cooking Lake carbonate platform and overlain by the Ireton Shale which forms the caprock to the oil-bearing leg on the updip side of the reef as well as for the proposed CO2 storage. A shale embayment occurs around some parts of the reef margin at the Mid-Leduc level. In order to assess seismic monitoring potential for the CO2 storage project, fluid substitution seismic modeling was undertaken. Gassmann fluid substitution modeling was undertaken using on-reef wells which penetrated the Cooking Lake platform below the reef. Porosity of the Leduc Formation was calculated from the density logs and ranged from 4% to 6%. Synthetic seismograms were calculated from the log data before and after fluid substitution with supercritical CO2 replacing brine. Gassmann fluid substitution calculations were computed for the entire thickness of the Leduc Formation (over a depth range from 1086 to 1324 m) for both on-reef wells. A P-wave velocity decrease of 4% is predicted to occur between 0% to about 40% CO2 saturation, assuming uniform CO2 saturation. For CO2 saturations above 40%, the P-wave velocity will increase slightly. In comparison, the S-wave velocity is calculated to increase almost linearly with CO2 saturation by a maximum of 0.6%, yielding an increase in Vp/Vs of about 4.5%. Seismic modeling was based on the changes in Leduc acoustic impedance predicted to occur between the wet in-situ reservoir and after replacement of pore fluids with supercritical CO2. From this modeling, a time delay of 4.3 ms is observed for reflections from the base of the Lower Leduc Formation, assuming that the entire reef interval has at least 40% CO2 saturation. An integrated surface seismic and vertical seismic profile time-lapse seismic program has been designed to monitor CO2 injection for HARP, planned to start by 2011. [Copyright &y& Elsevier]

Abstract: Characterization of the effects of cruise ship emissions on local air quality is scarce. Our objective was to investigate community level concentrations of fine particulate matter (PM2.5), nitrogen dioxide (NO2) and sulphur dioxide (SO2) associated with cruise ships in James Bay, Victoria, British Columbia (BC), Canada. Data obtained over four years (2005–2008) at the nearest air quality network site located 3.5km from the study area, a CALPUFF modeling exercise (2007), and continuous measurements taken in the James Bay community over a three-month period during the 2009 cruise ship season were examined. Concentrations of PM2.5 and nitrogen oxide (NO) were elevated on weekends with ships present with winds from the direction of the terminal to the monitoring station. SO2 displayed the greatest impact from the presence of cruise ships in the area. Network data showed peaks in hourly SO2 when ships were in port during all years. The CALPUFF modeling analysis found predicted 24-hour SO2 levels to exceed World Health Organization (WHO) guidelines of 20μgm−3 for approximately 3% of 24-hour periods, with a maximum 24-hour concentration in the community of 41μgm−3; however, the CALPUFF model underestimated concentrations when predicted and measured concentrations were compared at the network site. Continuous monitoring at the location in the community predicted to experience highest SO2 concentrations measured a maximum 24-hour concentration of 122μgm−3 and 16% of 24-hour periods were above the WHO standard. The 10-minute concentrations of SO2 reached up to 599μgm−3 and exceeded the WHO 10-minute SO2 guideline (500μgm−3) for 0.03% of 10-minute periods. No exceedences of BC Provincial or Canadian guidelines or standards were observed. [Copyright &y& Elsevier]

Abstract: Accuracy in population estimation from individual measurement has been traditionally a research focus in both theoretical and applied ecology. In forest sciences, estimation of productivity and value recovery of forest products is essential for decision-making to achieve the goal of sustainable forest management. In this paper, we review the basic structure of data in forest sciences, describe commonly used statistical procedures in obtaining population estimates, and examine the accuracy associated with the forest products value estimation using forest inventory data of Manitoba, Canada. Our results suggested that simplified statistical procedures could bring about a wide range of bias in estimating lumber value recovery at the stand level, and improved understanding of stand structure and its reconstruction through computer simulation could be essential in reducing the bias involved in the estimation. [Copyright &y& Elsevier]

Abstract: Research is ongoing to develop ways to reduce emissions of greenhouse gases (GHGs) from agricultural sources. A convenient technique to estimate emissions is to develop emission factors for a wide range of management practices. Default emission factors such as those given in the Intergovernmental Panel on Climate Change Tier I methodology are often used but these can result in substantial errors when applied to specific geographical regions. In this paper an interface was developed to link soil, climate and agricultural activity data in Canada with the DeNitrification and DeComposition (DNDC) model to create a modeling tool for estimating emission factors for changes in agricultural management. This tool was also designed to calculate country-specific IPCC Tier II emission factors for comparison against modeled results. The DNDC-Management Factor Tool (DNDC-MFT) was developed to automatically generate soil, climate and agricultural management model input data from national databases for estimating emissions factors for any of 462 ecodistricts across Canada. Six ecodistricts were selected across the major climatic regions to test the tool. The emission factors generated by the DNDC model were significantly different from Tier II values. Much variability in N2O emission estimates exist, partly due to limitations in certain biophysical processes in the model and partly due to quality of input data. The DNDC model is very sensitive to climate, size of initial soil C levels, and fertilizer application rates. We should also keep in mind that there is uncertainly associated with Tier II emission factors. The combined N2O and soil C factors estimated by the DNDC model are generally comparable to values that are being used to estimate Canada''s national inventory (Tier II/III) but only the tillage factor was found to be statistically similar. The DNDC-MFT will be useful for testing the ability of the DNDC model to generate GHG emission factors for many management scenarios across varying climatic regions in Canada. The framework can be extended to include improved versions of DNDC and other ecosystem models. [Copyright &y& Elsevier]

Abstract: In 1988, Dr. Kyoji Sassa proposed a geotechnical model [Sassa, K., 1988. Geotechnical model for the motion of landslides. In: Proceedings, 5th International Symposium on Landslides, vol. 1, pp. 37–56] to simulate landslide motion and to establish a theoretical framework for landslide simulation. In 2002, based on the experimental results of using a ring-shear apparatus for simulation of landslide motion, Wang and Sassa proposed a model for apparent friction coefficient change (which is a key parameter of landslide motion) that can be combined with Sassa’s original geotechnical model. As presented in the model for apparent friction coefficient change, a landslide is considered as a two-layer structure, i.e., a debris layer and a sliding zone. During landsliding, the thickness of the debris layer changes, while shear resistance changes in the sliding zone. In this paper, after a brief introduction of the two models, a parametric study is presented to show the differing importance of each parameter. Also included is a presentation of three case studies: The 1995 Fei Tsui Road landslide, and the 1995 Shum Wan landslide, both in Hong Kong, and the 1903 Frank slide in Alberta, Canada to show the advantage of combining the two models. [Copyright &y& Elsevier]

The article offers information on the Canadian National Calibration Reference Center (NCRC) for Bioassay and In Vivo Monitoring. The center, founded in 1982 as part of Health Canada's Radiation Protection Bureau (RPB), initially aimed to provide practical reference standards for the measurement of internal dose. As of 2009, its client types are those mandated by the Canadian Nuclear Safety Commission (CNSC) as participants in the in vitro, in vivo, and the internal dosimetry performance test programs, and those who participated voluntarily.

Changes in fire regimes are driving the carbon balance of much of the North American boreal forest, but few studies have examined fire-driven changes in evapotranspiration (ET) at a regional scale. This study used a version of the Biome-BGC process model with dynamic and competing vegetation types, and explicit spatial representation of a large (106 km2) region, to simulate the effects of wildfire on ET and its components from 1948 to 2005 by comparing the fire dynamics of the 1948–1967 period with those of 1968–2005. Simulated ET averaged, over the entire temporal and spatial modeling domain, 323 mm yr−1; simulation results indicated that changes in fire in recent decades decreased regional ET by 1.4% over the entire simulation, and by 3.9% in the last 10 years (1996–2005). Conifers dominated the transpiration ( EC) flux (120 mm yr−1) but decreased by 18% relative to deciduous broadleaf trees in the last part of the 20th century, when increased fire resulted in increased soil evaporation, lower canopy evaporation, lower EC, and a younger and more deciduous forest. Well- and poorly drained areas had similar rates of evaporation from the canopy and soil, but EC was twice as high in the well-drained areas. Mosses comprised a significant part of the evaporative flux to the atmosphere (22 mm yr−1). Modeled annual ET was correlated with net primary production, but not with temperature or precipitation; ET and its components were consistent with previous field and modeling studies. Wildfire is driving significant changes in hydrological processes by affecting mean stand age, forest species, and energy balance. These changes, particularly in poorly drained areas, may control the future carbon balance of the boreal forest. [ABSTRACT FROM AUTHOR]

Design for moisture control has now become an established part of building envelope design. Hygrothermal modeling tools, capable of simulating moisture transfer in materials, are a key element of the design process. There are three principle methods of moisture transfer in envelopes. They are, in order of magnitude, capillary action, vapour convection, and vapour diffusion. Wind-driven rain has the potential to deposit large amounts of liquid water on the exterior surface, as well inside walls through rain penetration, providing a significant source for moisture transport. Most hygrothermal models are capable of handling wind-driven rain impinging on or penetrating the surface of the envelope. Correct results presuppose the availability of reliable rain intensity data. Many data sets, however, do not record hourly rain intensities but qualitative intensities such as light, moderate, or heavy. This paper examines several methods for assigning quantitative values to weather observations available in Canada. Real data, such as data from rain gauges, is preferable although the latter have shortcomings. Differences in catch can be up to 50% depending on gauge type, size, and exposure. When only rain codes are available the values recommended by the local meteorological service can provide adequate estimates. In case where there is observer bias a better estimate can be obtained by adjusting the value for light rainfall. If very little information is available stochastic modeling of rainfall is possible though the accuracy, especially for individual months is low. [Copyright &y& Elsevier]

Canada is committed to reducing its greenhouse gas emissions to 6% below 1990 amounts between 2008 and 2012, and methane is one of several greenhouse gases being targeted for reduction. Methane production from ruminants is one area in which the agriculture sector can contribute to reducing our global impact. Through mathematical modeling, we can further our understanding of factors that control methane production, improve national or global greenhouse gas inventories, and investigate mitigation strategies to reduce overall emissions. The purpose of this study was to compile an extensive database of methane production values measured on beef cattle, and to generate linear and nonlinear equations to predict methane production from variables that describe the diet. Extant methane prediction equations were also evaluated. The linear equation developed with the smallest root mean square prediction error (RMSPE, % observed mean) and residual variance (RV) was Eq. I: CH4, MJ/d = 2.72 (±0.543) + [0.0937 (+0.0117) × ME intake, MJ/dJ + [4.31 (±0.215) × Cellulose, kg/dj - [6.49 (±0.800) × Hemicellulose, kg/d] - [7.44 (±0.521) × Fat, kg/dI [RMSPE = 26.9%, with 94% of mean square prediction error (MSPE) being random error; RV = 1.13]. Equa- tions based on ratios of one diet variable to another were also generated, and Eq. P, CH4, MJ/d = 2.50 (±0.649) - [0.367 (±0.0191) × (Starch:ADF)] + [0.766 (±0.116) × DM1, kg/d], resulted in the smallest RMSPE values among these equations (RMSPE = 28.6%, with 93.6% of MSPE from random error; RV = 1.35). Among the nonlinear equations developed, Eq. W, CH4, MJ/d = 10.8 (±1.45) × (1 - e{-0.141 (±0.0381) × DMI, kg/d}) performed well (RMSPE = 29.0%, with 93.6% of MSPE from random error; RV = 3.06) as did Eq. W3, CH4, MJ/d = 10.8 (±1.45) × (1 - e.{{-|-0.034 × (NFC/NDF) + 0.228] × DM1, kg/d}] (RMSPE = 28.0%, with 95% of MSPE from random error). Extant equations from a previous publication by the authors performed comparably with, if not better than in some cases, the newly developed equations. Equation selection by users should be based on RV and RMSPE analysis, input variables available to the user, and the diet fed, because the equation selected must account for divergence from a "normal" diet (e.g., high-concentrate diets, high-fat diets). [ABSTRACT FROM AUTHOR]

To assess the cost-effectiveness of abatacept compared to different biologic treatment strategies for moderate to severe rheumatoid arthritis based on current medical practices in Canada. A model was constructed to assess the cost-effectiveness of various biologic treatments over a 2-year time horizon, using two effectiveness endpoints: “low disease activity state” (LDAS) and “remission”. Abatacept, as first biologic agent after an inadequate response to DMARDs, provides greater treatment success rate for achieving LDAS (29.4% versus 15.6%) and remission (14.8% versus 5.2%), and appears significantly more cost-effective compared to the sequential use of anti-TNF agents ( p < 0.001). Abatacept, as second biologic agent after an inadequate response to one anti-TNF agent, provides greater treatment success rate for achieving LDAS (17.1% versus 10.2%) and remission (7.4% versus 3.9%) and appears significantly more cost-effective compared to the sequential use of anti-TNF agents ( p < 0.001). Abatacept is a cost-effective strategy in patients with an inadequate response to DMARDs or to one anti-TNF agent. [ABSTRACT FROM AUTHOR]

Abstract: Two non-indigenous botryllid ascidian species - Botryllus schlosseri (golden star tunicate) and Botrylloides violaceus (violet tunicate) - have become established in British Columbia (BC), Canada. One species, B. schlosseri, is native to Europe while the other, B. violaceus, is native to Asia. Environmental tolerances of both species are poorly understood. We examined the effects of temperature and salinity on growth, survival, and reproduction of these species in the laboratory in order to characterize their environmental tolerances and preferences. Laboratory-raised juvenile colonies were studied using a two-factorial experimental design with five levels of temperature (5, 10, 15, 20, 25 °C) and five levels of salinity (14, 20, 26, 32, 38‰). Both B. schlosseri and B. violaceus possessed broad temperature and salinity tolerances, but B. schlosseri was slightly more euryhalinal than B. violaceus. Generally, B. schlosseri survived environmental conditions of 10-25 °C and 14-38‰, exhibited positive growth at 10-25 °C and 20-38‰, and attained its largest colony sizes at 15-20 °C and 20-38‰. Botrylloides violaceus tolerated environmental conditions between 5-25 °C and 20-38‰, demonstrated positive growth at 15-25 °C and 26-38‰, and attained its largest colony sizes at 20-25 °C and 26-38‰. Results from the laboratory experiment were then used in a modeling exercise to determine the coastal areas of BC that these organisms might be likely to exist in or invade, based on near-surface temperatures and salinities. The model predicted that no areas were totally unsuitable for survival and growth of either species (based solely on temperature and salinity tolerances), with the most suitable locations being along the west coast of Vancouver Island, a region with significant shellfish aquaculture activity. [Copyright &y& Elsevier]

Abstract: The performances of five carbon (C) and nitrogen (N) cycling models (FLDM, CENTURY, SOMM, DOCDOM and CANDY) were compared for their ability to quantify mass and N remaining in 10g leaf-litterbags across the wide range of litter types and sites of the Canadian Intersite Decomposition Experiment (CIDET), over a 6-year period. These models differ in their structure and assumptions, number of compartments, predictor variables and coefficients. Calibrated model outputs displayed similar but not identical trends for mass and N remaining, but differed substantially in mass and N contents per model-defined compartments. The quality of fit between model calculations and data varied as follows: FLDM>CENTURY>DOCMOD>CANDY>SOMM for mass remaining (0.73< r 2 <0.92), and FLDM>DOCMOD>CENTURY>SOMM>CANDY for the changing N concentrations inside the bags (0.40< r 2 <0.80). FLDM calculations were the most consistent by CIDET site (21), litter type (10), and years of litterbag retrieval (1993–1998). Best-fitted models were used to project mass remaining and N concentrations inside the bags over the next 50 years, using mean July and January air temperatures, and annual precipitation and initial litter composition as independent predictor variables. Projected model outputs converged for mass remaining, but diverged for the N concentrations, i.e., (1±0.5)g and (2±1)% at year 50, respectively. [Copyright &y& Elsevier]

Abstract: Recent studies of vegetation phenology of northern forests using satellite data suggest that the observed earlier spring increase and peak amplitude of the normalized difference vegetation index (NDVI) are a result of climate warming. In addition to undergoing an increase in temperature, the northern forests of Canada have also seen a dramatic increase in area burned by wildfire over the same time period. Using the Canadian Large Fire Database, we analyzed the impact fire had on the phenological dates derived from fitting a logistical model to yearly data from 2004 for several different subsets of both AVHRR-NDVI and MODIS LAI in wildfire dominated terrestrial ecozones. Fire had a significant but complex effect on estimated phenology dates. The most recently burned areas (1994–2003) had later green-up dates in two ecozones for AVHRR data and all ecozones for MODIS. However, older forested (not burned during 1980–2003) had estimated green-up dates 1 to 9 days earlier than the entire forested area in the MODIS LAI data. These data corroborate studies in Canada and demonstrate that fire history is influencing boreal forest phenology and growing season LAI. [Copyright &y& Elsevier]

This study focuses on synoptic-scale transport of ozone as it affects Southern Ontario. This process has been analyzed for the summer in 2001, as an example period of a frequent event that usually occurs during summer in this region. The work was carried out using the mesoscale modeling system generation 5 (MM5)/sparse matrix operator kernel emission modeling system (SMOKE)/community multiscale air quality (CMAQ) regional air quality modeling system, together with observational data from monitoring stations located throughout the modeling domain. Other different analyses have been carried out to supply more information apart from that obtained by the modeling system. A back-trajectory cluster methodology was used to evaluate the magnitude of the effects studied and an analysis of wind direction and cloud cover revealed a significant correlation with ozone concentration (R 2=0.5–0.6). Synoptic sea-surface level pressure (SLP) patterns were also analyzed to examine other meteorological aspects. The contribution of natural background ozone to the total amount within the region was compared with that from synoptic-scale transport. The influence of emission of pollutants from selected areas on ozone concentrations in Southern Ontario was also analyzed. As relevant results of these analyses, the model predicts that background ozone is the largest contribution to the ground-level ozone concentration during days in which low values were recorded. However, when smog episodes occurred, the model predicts that around 60% of the ozone formed by anthropogenic emissions of pollutants is due to releases from nearby US states. [Copyright &y& Elsevier]