bluuebunny/crossref_metadata_2025 huggingface dataset:
Elevated Expression of Macrophage Migration Inhibitory Factor Promotes Inflammatory Bone Resorption Induced in a Mouse Model of Periradicular Periodontitis
Authors: Howait Mohammed , Albassam Abdullah , Yamada Chiaki , Sasaki Hajime , Bahammam Laila , Azuma Mariane Maffei , Cintra Luciano Tavares Angelo , Satoskar Abhay R. , Yamada Satoru , White Robert , Kawai Toshihisa , Movila Alexandru
Published: February 2019

Locally produced osteoclastogenic factor RANKL plays a critical role in the development of bone resorption in periradicular periodontitis. However, because RANKL is also required for healthy bone remodeling, it is plausible that a costimulatory molecule that upregulates RANKL production in inflammatory periradicular periodontitis may be involved in the pathogenic bone loss processes. We hypothesized that macrophage migration inhibitory factor (MIF) would play a role in upregulating the RANKL-mediated osteoclastogenesis in the periradicular lesion. In response to pulp exposure, the bone loss and level of MIF mRNA increased in the periradicular periodontitis, which peaked at 14 d, in conjunction with the upregulated expressions of mRNAs for RANKL, proinflammatory cytokines (TNF-α, IL-6, and IL-1β), chemokines (MCP-1 and SDF-1), and MIF’s cognate receptors CXCR4 and CD74. Furthermore, expressions of those mRNAs were found significantly higher in wild-type mice compared with that of MIF−/− mice. In contrast, bacterial LPS elicited the production of MIF from ligament fibroblasts in vitro, which, in turn, enhanced their productions of RANKL and TNF-α. rMIF significantly upregulated the number of TRAP+ osteoclasts in vitro. Finally, periapical bone loss induced in wild-type mice were significantly diminished in MIF−/− mice. Altogether, the current study demonstrated that MIF appeared to function as a key costimulatory molecule to upregulate RANKL-mediated osteoclastogenesis, leading to the pathogenically augmented bone resorption in periradicular lesions. These data also suggest that the approach to neutralize MIF activity may lead to the development of a therapeutic regimen for the prevention of pathogenic bone loss in periradicular periodontitis.
Programming Effects of Pubertal Lipopolysaccharide Treatment in Male and Female CD-1 Mice
Authors: Sharma Rupali , van Mil Spencer , Melanson Brett , Thomas Bronwen J. , Rooke Jasmine , Mallet Jean-François , Matar Chantal , Schwarz Jaclyn M. , Ismail Nafissa
Published: February 2019

Puberty is a critical period of development marked by sexual, immune, and neural maturation. Exposure to stress during this period can lead to enduring changes in brain functioning and in behavior; however, the underlying mechanisms and the programming effects of stress during puberty remain unknown. Therefore, the objective of this study was to investigate the programming effects of pubertal immune challenge in response to a homotypic stressor later in life in CD-1 mice. Age and sex differences in the peripheral and central cytokine levels, along with sickness behavior and telemetry data, were analyzed following the secondary treatment. The results showed that pretreatment with LPS attenuated the immune response to a second homotypic challenge. Males pretreated with LPS during puberty and in early adulthood displayed an attenuated hypothermic response following the second LPS treatment compared with saline-pretreated controls, which is consistent with the attenuated peripheral IL-6 and IFN-γ concentrations. Females pretreated with LPS during puberty displayed lower IL-1β, TNF-α, and IL-6 mRNA expression in the prefrontal cortex following the secondary immune challenge compared with saline controls. The results of this study show that exposure to LPS during puberty programs the peripheral and central immune responses, resulting in an attenuated immune response following a subsequent homotypic stressor. Thus, exposure to an immune challenge during puberty affects immune function later in life, which could permanently affect brain function and have implications on mental health.
New Insights into Lymphocyte Differentiation and Aging from Telomere Length and Telomerase Activity Measurements
Authors: Fali Tinhinane , Papagno Laura , Bayard Charles , Mouloud Yanis , Boddaert Jacques , Sauce Delphine , Appay Victor
Published: February 2019

αβ CD8+, γδ, and NK lymphocytes are fundamental effector cells against viruses and tumors. These cells can be divided into multiple subsets according to their phenotype. Based on progressive telomere attrition from naive to late effector memory cells, human CD8+ T cell subsets have been positioned along a pathway of differentiation, which is also considered as a process of lymphocyte aging or senescence. A similar categorization has not been clearly established for γδ and NK cell populations. Moreover, the distinction between the aging of these populations due to cellular differentiation or due to the chronological age of the donor has not been formally considered. In this study, we performed systematic measurements of telomere length and telomerase activity in human αβ CD8+, γδ, and NK lymphocytes based on subset division and across age to address these points and better understand the dichotomy between differentiation and temporal aging. This approach enables us to position phenotypically distinct γδ or NK subsets along a putative pathway of differentiation, such as for CD8+ T cells. Moreover, our data show that both cellular differentiation and donor aging have profound but independent effects on telomere length and telomerase activity of lymphocyte subpopulations, implying distinct mechanisms and consequences on the immune system.
Whole genome sequencing based typing and characterisation of Shiga-toxin producing Escherichia coli strains belonging to O157 and O26 serotypes and isolated in dairy farms
Authors: Pasquali Frederique , Palma Federica , Trevisani Marcello , Parisi Antonio , Lucchi Alex , De Cesare Alessandra , Manfreda Gerardo
Published: February 2019

In the present study, the genetic relationships as well as the virulome and resistome of newly sequenced O26 and O157 Shiga-toxin producing E. coli (STEC) isolates, collected from dairy farms in Italy, were investigated in comparison to publicly available genomes collected worldwide. The whole genome of Italian isolates was sequenced on Illumina MiSeq Platform. Reads quality control, de novo draft genome assembly, species confirmation and the 7-loci Multi-Locus Sequence Type assignment were performed using INNUca pipeline. Reference-based SNPs calling was performed on O157 and O26 genomes, separately, mapping contigs to high-quality finished genomes. Virulence and antimicrobial resistance determinants were detected in silicousing the tool ABRicate. Phylogenetic reconstructions revealed that genomes clustered mainly based on their 7-loci MLST type. The virulome of tested genomes included 190 determinants. O157 genomes carried chu genes associated to heme mediated iron uptake, whereas O26 genomes harboured genes ybt associated to siderophore mediated iron uptake. Resistome analysis showed the presence of tet(34) on all but one O157 genomes and on only one O26 genomes. Only 4 genomes carried genes associated to multiresistance. In the present study, the genes chu and ybt were identified as potential biomarker for the differentiation of O157 and O26 serotypes.
Update on Ontario's water quantity management (policy, program and science) review
Authors: Brodie-Brown H
Published: February 2019

Ontario's Government for the People is committed to preserving water for families now and for future generations. To achieve this Ontario is undertaking a thorough review of the province's water taking policies, programs and science tools to ensure that vital
water resources are adequately protected and sustainably used in the face of a changing climate and continued population growth. Ontario has extended the moratorium on water taking permits by one year, now ending December 31, 2019, to allow time to complete this review and consult on any recommended
enhancements.
At the 2018 OGS-GSC Workshop, the ministry presented, "The Science behind Ontario's Water Quantity Management Review" and outlined key aspects of the water quantity science work being undertaken to ensure a robust and adaptive approach to water resources management into the future, and the water
quantity scientific work being undertaken to improve our understanding of water resources knowledge on Ontario. The ministry's consultant, BluMetric Environmental Inc. (BMEI) presented an outline of water quantity science and jurisdictional reviews and water quantity assessments being undertaken.
The Ministry will provide an update on the moratorium extension and the water quantity management review, particularly the science components and some of the findings of the BMEI project. As identified in the draft "Preserving and Protecting our Environment for Future Generations: A Made-in-Ontario
Environment Plan" the focus moving forward will include examining approaches to assess and manage multiple water takings, establish priorities for different water uses, prepare and respond to drought conditions and ensure the knowledge gained through the drinking water source protection program
helps inform our water management programs. (https://prod-environmental-registry.s3.amazonaws.com/2018-11/EnvironmentPlan_1.pdf)
Applications of borehole geophysical logs in groundwater studies
Authors: Crow H , Burt A , Knight R
D , Mulligan R , Pugin A J
-M , Russell H A J
Published: February 2019

Over the past 5-year program cycle, the Geological Survey of Canada (GSC) has completed downhole geophysical logging to i) support regional stratigraphic studies, ii) conduct velocity analyses for seismic reflection surveys, iii) support hydrogeophysics studies,
iv) adopt new methodologies, and v) maintain a national calibration facility. The geophysical logs provide in situ information on physical and chemical properties of sediment and rock, and of borehole fluid parameters to support groundwater studies through improved lithological characterization.
Using examples from different project settings across southern and eastern Ontario, the benefits of an integrated approach to geophysical, geological, geochemical, and hydrogeological datasets will be discussed.
In collaboration with the Ontario Geological Survey's 3D Quaternary sediment mapping projects in Southern Ontario, the GSC collected geophysical logs in 20 cored boreholes in the Niagara and central Simcoe County regions. The integration of sediment core examination with geophysical logs supported
an enhanced understanding of local complex geological processes. While significant changes in log responses at key stratigraphic boundaries helped to distinguish potentially water-bearing coarse-grained units from fine-grained aquitards, logs yielded equally useful information about subtle changes
in grain sizes, mineralogy, and velocity structure related to depositional conditions.
At two sites east of Toronto, geophysical logs were interpreted together with chemostratigraphic data to identify geochemical changes in the sediment column. Elemental variations were well aligned with geophysical log responses and changes in grain size. Geophysical logs also identified non-chemical
changes in sediment, such as variations in porosity/density, or pore fluid chemistry, providing highly complementary datasets for detailed litho-stratigraphic analyses.
Over the past few years, new technologies have been applied in GSC bedrock and sediment calibration boreholes. The use of a GSC-developed controlled frequency vibratory source is allowing for selection of source parameters fine-tuned for different geological settings. This is showing great potential
for high-resolution downhole velocity testing, supporting optimized reflection seismic velocity conversions. An experimental deployment of slim-hole borehole magnetic resonance (BMR) tools in calibration holes around Ottawa was conducted in bedrock and post-glacial sediments. These instruments are
designed to measure formation porosity and pore size distribution without the use of radioactive sources. Although the influence of magnetite-bearing minerals from Shield-derived sediments is a topic of ongoing study, early qualitative results from the tests are encouraging. The evaluation of new
tools using calibration datasets is an important driver for the ongoing work to update geophysical calibration facilities.
Monitoring groundwater changes in southern Ontario using GRACE satellite gravity measurements
Authors: Crowley J W
Published: February 2019

The Gravity Recovery and Climate Experiment satellite mission(s) (GRACE) have been measuring variations in the Earth's gravitational field since 2002. Changes in groundwater, melting glaciers, ocean circulation, and large deformations associated with post-glacial
rebound, continental tectonics and earthquakes all produce signals that can be detected and monitored. In this talk, I will provide an introduction to the GRACE missions, briefly mention some new analysis methods being developed at the Canadian Geodetic Survey, and show some new results related to
groundwater variations in Southern Ontario. The new method uses watershed regions from the Canadian National Frameworks Dataset to build mascons (regions of interest) for Canada, ensuring that the boundaries of the numerical method correspond to real hydrological boundaries and reducing leakage
between adjacent watersheds. Three distinct mascons are designed using watershed geometry that include Lake Huron, Lake Erie, and Lake Ontario and estimates of total water storage (TWS) change are obtained using GRACE data from the Center for Space Research (U. of Texas at Austin) spherical harmonic
Release 5 dataset. These TWS estimates are split into a contribution from surface water (SW) change and a common large-scale background signal across Southern Ontario that represents groundwater, soil moisture, snow and ice. The surface water changes are almost entirely due to lake level changes
within the Great Lakes and can be compared to water level observations from gauges on the lakes provided by the Canadian Hydrographic Service. The GRACE derived and observed lake level changes agree well with correlations of 0.95, 0.92, and 0.82 for the Lake Huron, Erie, and Ontario regions,
respectively. The amplitudes also agree well and, to our knowledge, this is the first study to effectively detect the changing water levels of the different Great Lakes using GRACE. The common background signal is found to have peak to peak variations of ~20 cm equivalent water thickness (EWT)
and is compared to 301 wells from across Southern Ontario (data from the Provincial Groundwater Monitoring Network). The signals agree well with a correlation of 0.85. This result has important implications for the relative size and/or dynamics of the groundwater and remaining surface terms (soil
moisture, snow and ice). Furthermore, variations in water storage from groundwater are found to be comparable to variations in water storage from the Great Lakes themselves - highlighting the importance that groundwater plays in any water budget of the Great Lakes system. Comparisons between
individual groundwater wells and that of GRACE reveal the spatial extent of wells that show regional signals (high correlation) and those that show more local variability (poor correlation). Wells that correlate poorly reveal additional spatial patterns and the influence of local topography,
geology, and water usage.
Intersections of wildfire, water and land: using groundwater science to reduce risks to water supplies
Authors: de Jong S , Leybourne M , Russell H A J , DeGeer H , Strychar L
Published: February 2019

For over three weeks, fire suppression teams sought to control the 2018 Parry Sound 33 Wildfire (covering 11,362 hectares in northeastern Ontario). Following the fire, the wide spread concern has been the impact of the Parry Sound 33 Wildfire upon the Key Harbour
First Nation's and Henvey Inlet First Nation's water security. This in turn has sparked groundwater geochemistry questions. Our research seeks to understand one question: how can the post-Parry Sound 33 fire water quality research provide guidance for future ground water research in Southern Ontario
and across Canada?
Informed by research from i) post fire mobilization of contaminants into surface water resources; ii) short term impacts of fire events on karst; and iii) community based fire management, this project has several objectives:
a) Provide gap analysis of the post-fire groundwater for drinking water quality research;
b) Detail how Canadian universities and research institutions take a strategic view of post-fire water quality research to support land use planning and public health and safety initiatives;
c) Document actionable information products created to communicate to communities how to manage post fire water quality.
This paper presents preliminary results of our research, noting:
Contamination of high quality potable water in groundwater can occur through natural events such as wildfires because wildfires modify the surface environment by combusting vegetation and changing soil properties;
Most prior research on post-fire water quality research has focused on surface water to determine fire-prone forested water source areas;
The emerging field of post fire contamination of water sources is receiving considerable attention, evidenced by the 2018 NSERC funded Water Institute/University of Waterloo project. But there is little research being done to understand the vulnerabilities of groundwater aquifers to post fire
debris, sediment and chemical constituents (indicators that could be included in future assessments).
This paper is intended to inform discussions on the preparation of suitable post fire water management plans in order to maintain drinking water quality in a cost-effective manner.
A development of a fully integrated groundwater-surface-water modelling platform for the Phanerozoic basin region of southern Ontario
Authors: Frey S , Khader O , Taylor A , Russell H , Lapen D , Berg S , Sudicky E
Published: February 2019

In early 2018, construction began on a HydroGeoSphere (HGS) fully-integrated GW-SW modelling platform for Southern Ontario, with high resolution subsurface hydro-stratigraphy based on the GSC-OGS 3D geological modelling initiative.
In total, four HGS models were constructed, using a combination of coarse (41,000 nodes per layer) and fine (133,000 nodes per layer) unstructured finite element meshes, and with the full Phanerozoic sequence (represented by 21 hydrostratigraphic/soil layers) as well as a version with the
Phanerozoic sequence cut off at the sulfur-brine interface (represented by 16 hydrostratigraphic/soil layers). During model construction, extensive effort was devoted to characterizing and reducing model structural uncertainty, with the end result being a heterogeneous subsurface parameterization
(which includes effective representation of key karst units) underlying a temporally and spatially varying land surface that incorporates key driving factors for overland flow and evapotranspiration.
Results from validation and testing demonstrate that the models can successfully capture the spatially varying transient behavior of the coupled SW and GW flow system at the regional scale, based on simulated vs observed surface water flows and groundwater heads at a respective 27 hydrograph
locations and 300 monitoring well locations dispersed across the model domain. Further comparison of the simulation results from the different models combined with the different levels of temporal forcing (steady-state vs. transient) provides insight on how model spatial and temporal resolution can
influence simulated heads and stream flows, and can thus be used to help determine prudent use cases for models incorporating varying levels of detail.
With the proof-of-concept now near completion, there are numerous applications for the modelling platform and its underlying database to be used to further develop our understanding of regional scale hydrologic processes within Southern Ontario, as well as to inform smaller scale investigations that
would benefit from insight on how regional flow systems may be influencing localized areas of interest. Furthermore, the platform will also serve as a tool to help identify current limitations in our knowledge of regional groundwater flow, to help guide future data collection initiatives, and to
quantitatively test hypotheses relating to how different conceptual model realizations of subsurface hydrostratigraphy can influence hydrologic behavior.
This presentation will provide a brief overview of the methodology employed towards model construction, followed by a discussion of model performance and spatial-temporal sensitivities, and will finish with a set of example applications targeting questions relating to how groundwater - surface water
interactions govern inflow to the Great Lakes under different climate conditions.
Applications of a regional-scale integrated modelling platform towards watershed-level hydrologic insights
Authors: Frey S , Stonebridge G , Berg S , Steinmoeller D , Lapen D , Khader O , Erler A , Sudicky E
Published: February 2019

Persistent questions exist on how a regional scale model, such as the one developed for Southern Ontario, can be employed as a tool to address local level questions. While the spatial resolution of the regional model may be high enough for big-picture
applications, it is arguably not high enough to provide useful insights on highly-dynamic small-scale hydrologic behavior or operational aspects of watershed management. In order to meet the needs of smaller scale applications, a set of HydroGeoSphere (HGS) fully-integrated groundwater - surface
water models has been constructed for the 12 major watersheds that lie within the bounds of the regional model. These models have been constructed with a much higher level of spatial resolution than the regional model (i.e. with Strahler order 2 stream networks as opposed to Strahler order 3) and
with full representation of the surface water features as channel elements within the model, which creates a more representative depiction of watershed and sub-watershed scale hydrologic behavior. As the underlying database upon which the watershed models are constructed is amalgamated across
Southern Ontario, these models all share a consistent hydrostratigraphy, soil, and landcover representation, which in turn creates a uniform simulation framework that aligns with regional model behavior. However, in recognition of the fact that higher resolution model construction data may be
available and/or required for smaller scale applications, the watershed models can be efficiently reconstructed using data in standard GIS formats.
In addition to being able to use each of the 12 watershed models as a pre-built standalone fully-integrated model for individual watersheds, the full set of models is now running operationally as a surface water forecasting system for the whole of the Southern Ontario model domain. Using an ensemble
set of weather forecasts and an advanced monitoring data assimilation scheme, surface water forecasts are being generated at daily frequency for a two week forecast interval for 100's of locations across Southern Ontario. Already, a demonstrated strength of the platform is that flows at ungauged
locations (as well as known gauging locations) can be predicted with some certainty given that HGS employs a physics-based mass conservative approach for simulating water movement within the highly dynamic GW-SW system in Southern Ontario.
In order to disseminate output from the hydrologic forecasting platform to watershed stakeholders, a cloud based portal has been developed with watershed-level dashboards and on-the-fly analytic functionality. While surface water flows are currently the only forecast endpoint, platform development
is ongoing, with plans to release operational forecasts for other components of the hydrologic cycle in future releases.
Optimization of low impact development placement through shallow subsurface characterization
Authors: Harvey T , Wilson M
Published: February 2019

Urban stormwater is estimated to account for approximately 30% of the phosphorus loading to Lake Simcoe. In addition to phosphorus, urban stormwater from impervious surfaces can contribute sediment, hydrocarbons, and metals to local water features and
urbanization can cause reduced recharge to groundwater systems. As a result, the Lake Simcoe Protection Plan (2009) calls for improvements to the management of stormwater for both existing and future development with a goal to decrease phosphorous loadings and to minimize changes to the water
balance. Improved urban stormwater management can be accomplished through several means including retrofitting existing development with low impact development (LID) and using LID for future development projects. As a direct result of the Plan, LID implementation has increased within the watershed
in recent years.
Determining the most suitable locations for LID placement requires an understanding of the shallow subsurface including the geology and hydrogeology, as well as current land use and policy limitations. To help guide LID placement, the Shallow Subsurface Characterization Project aims to provide an
improved understanding of the shallow subsurface through the development of a GIS layer that prioritizes possible locations for LID projects within the East Holland River subwatershed. The GIS layer has been developed using geologic and static water level data provided by the Regional Municipality
of York and available through the Oak Ridges Moraine Groundwater Program.
Based on this improved understanding of the shallow subsurface environment, the final product is a single easy-to-use GIS layer that characterizes the watershed into areas that are deemed to be of low, medium, or high priority for LID placement. This will allow for a simple desktop evaluation of the
most appropriate locations for LID retrofits, even for staff or members of the public that have limited hydrogeologic knowledge. The long term goal is for the layer to be available on the LSRCA website to municipalities, stormwater engineers, planners, students, and anyone interested in LID within
the East Holland River subwatershed.
Are we on the right track? A panel discussion on the future direction of groundwater management in Ontario
Authors: Holysh S , Stephens J , Belanger D , Buttle J , Di'Iorio T , Doyle V , Rudolph D
L
Published: February 2019

This panel discussion will focus on whether, as a Province, Ontario is adequately planning for the future of our water resources. Recent developments related to the Greater Golden Horseshoe Growth Plan, the Greenbelt Plan, the Niagara Escarpment Plan and the Oak
Ridges Moraine Conservation Plan, as well as the expected impacts of climate change, will all figure into the conversation. Although the dialogue among panelists is expected to look broadly at water management and the current state of efforts to prepare for the future, there will be an emphasis on
groundwater resources. Decisions affecting water resources are made by policy makers, technical staff, and those responsible for issuing approvals on a daily basis. These decisions range from land use planning to water allocation targets to wastewater treatment requirements.
It has been almost 20 years since the tragic events of Walkerton highlighted additional needs for improved management of Ontario's water resources and in particular its groundwater. With the passing of the Clean Water Act in 2006, the past decade has seen considerable investment, primarily through
the Drinking Water Source Protection program. This investment has ranged from the collection of water related data, the technical synthesis of these data, in many cases into sophisticated numerical groundwater models, and an overall improvement in our understanding of how water moves through
Ontario's watersheds. In the current transition to a new government with a focus on curtailing public expenditures, what is the most appropriate way forward to capitalize on this investment and to ensure that future practitioners do not lose the knowledge gained from these activities? Is it even in
danger of being lost?
Panel members bring a diverse range of views and expertise to the discussion and will be prepared to offer their insights into some of Ontario's key ongoing and upcoming water related challenges and opportunities.
Are Ontario's water related policies and programs being effectively implemented to support long-term sustainability of the resource?
How are we monitoring the impact of our decisions?
Are our actions pro-active or reactive?
Is the acquisition of water related data sufficient to inform decision-making?
Are the data adequately managed and readily accessible to those making planning and technical decisions?
Is research headed in the right direction?
Are agencies at the Federal, Provincial and Municipal levels sufficiently engaged and coordinated?
Being blessed with a seemingly abundance of water, has Ontario been too complacent in how we currently make decisions with respect to our water resources?
Following introductory comments from panel members, there will be an engaging and insightful discussion surrounding the future of water management in Ontario.
Geochemistry of southern Ontario Quaternary sediments
Authors: Knight R D , Bajc A F , Kjarsgaard B A , Crow H , Stepner D A
J , Sharpe D R , Russell H A J
Published: February 2019

Geochemical analysis constrained by stratigraphic units with detailed sampling of continuous core is rare in glaciated basins. The up to 200 m plus thickness of surficial sediment cover across 74,000 km2 area of southern Ontario (S-ON) and the presence of many
hundred continuously cored boreholes provided an opportunity to investigate the chemostratigraphy of a large glaciated basin. The S-ON basin setting over Phanerozoic sedimentary carbonate and shale, and bounded by igneous and metamorphic rocks of Canadian Shield, provides an ideal setting for
geochemical provenance studies and methods development. Geochemical analysis of 3,815 surficial sediment samples from 53 boreholes have been analysed via portable X-ray fluorescence spectrometry (pXRF) and traditional laboratory geochemical analytical methods.
Comparison of geochemistry from ICP-ES/MS and with pXRF indicates good characterization of the basin chemistry by the laboratory and pXRF analysis methods. Significant changes in elemental concentrations within individual cores are identified in multiple contexts, i) across formation contacts, ii)
internally within formations, iii) absence of change across formation boundaries. These likely represent changes in depositional processes and provenance between Precambrian Shield and Paleozoic sources. Changes in elemental concentrations are commonly not correlated between boreholes at either the
formation or sub formation level. On a regional scale, the geochemical ratio of CaO+MgO/SiO2+Al2O3 provides a Provenance Indicator (PI) to determine elemental contributions from a Paleozoic carbonate source relative to contributions from Precambrian Shield sources. As calcium and magnesium occurs in
markedly higher concentrations in Paleozoic carbonate rocks, a higher PI value reflects greater input of material derived from these Paleozoic sedimentary rocks. Examination of the Newmarket Till using this PI shows a correlation between the amount of carbonate-derived material in the till-matrix
and sampling distance relative to the shield margin indicates the deposition of increasingly carbonate-rich surficial sediments to a maximum at approximately 80-100 km south of the Shield-margin. Additionally to the PI, a geochemical distinction is observed between sediments deposited east
(carbonate dominated) and west (dolomite dominated) of the Niagara Escarpment. Elevated MgO and CaO west of the Niagara Escarpment (Catfish Creek Till) indicates sourcing of Silurian dolomite, whereas east of the Escarpment (Newmarket Till) CaO-rich till is due to sourcing of Ordovician limestone.
The geochemical study of Quaternary sediments in southern Ontario has not found any evidence of elemental concentrations that might adversely affect groundwater quality and human health.
InSAR measurement of surface deformations in south Ontario
Authors: Li J , Wang S , Michel C , Russell H A
J
Published: February 2019

Detection of surface deformation can be measured using InSar, a geodetic technique that calculates the interference pattern which results from a difference in phase between images acquired by synthetic aperture radar (SAR). Ground surface deformation, in
particular land subsidence is caused by numerous factors, such as: tectonic motion, sediment compaction, thawing permafrost, increased surface loading, Glacial Isostatic Adjustment (GIA), hydro-chemical erosion of karst, decomposition of organic material in soils, mining, anthropogenic fluid
withdrawal and surface water/drainage management. Groundwater applications have commonly been completed in areas of extreme subsidence due to dehydration and collapse of fine grained sediment textures; such as in the central valley of California, Nevada, and the Mexico city area. This study examines
whether there is potential application of this technique to measure changes in surface elevation in southern Ontario and whether it can be related to changes in groundwater storage. For the southern Ontario study five datasets were used to assess the ground surface deformation and the
hydrogeological/hydrologic conditions within the imagery extent. Datasets included: a set of 40 Radarsat-2 images spanning five years, GPS weekly solutions, Real-time kinematic (RTK) gps data, groundwater levels, terrestrial water storage data derived from GRACE satellites and hydrologic data from
the Provincial Groundwater Monitoring Network (PGMN).
Differential synthetic aperture radar interferometry (D-InSAR) has sub-centimetre precision and high spatial resolution over a large area. To eliminate some of the noise and to reduce geometrical distortions (multilook) images were averaged to a 50 m resolution. A stable reference site RTK TWOO was
used a reference point. The TWOO GPS measurements were then added to the InSAR time series deformation maps.
Obtaining a coherent signal was difficult and resulted in clustering of signal return from urbanized areas. The roofs and corners of the buildings in urbanized areas can form permanent scatterers, resulting in a more coherent signal. Across the study area, an annual rate of 1 mm to 10 mm of
subsidence is observed. The greatest amount of subsidence (> 8 mm/year) is observed along the shore of Lake Ontario. In the absence of a field campaign to support validation the study has concluded that any viable signal attributed to specific geological - hydrogeological controls is
within the signal-noise ratio of the study.
Using 222-radon surveys and regional scale groundwater models to evaluate groundwater discharge to Lake Simcoe
Authors: Robinson C , Wallace H , Wexler E J , Malott S
Published: February 2019

Groundwater discharge can be an important pathway for delivering pollutants to large lakes, but this pathway is often overlooked. To understand the potential impact of groundwater inputs on lake water quality, the volume of groundwater discharge, the spatial
distribution of this discharge, and the history of the discharging groundwater must be quantified. This study uses offshore 222-radon surveys together with regional scale numerical groundwater models to evaluate groundwater discharge to Lake Simcoe. In-lake 222-radon concentration data was first
used to identify groundwater discharge hotspots along the shoreline and quantify groundwater discharge rates. The 222-radon results, which compared well with the regional scale numerical model results, were then used to provide insights into hydrogeological factors controlling groundwater discharge
to Lake Simcoe. Key factors included the permeability of nearshore sediments, proximity of the shoreline to moraine recharge areas, absence of streams along the shoreline, and presence of tunnel channel aquifers. Finally, the numerical model along the north shoreline of Lake Simcoe was applied to
characterize groundwater discharge pathways, evaluate the land use in the recharge areas, and assess potential impacts of the groundwater inputs on lake water quality trends. The study presents a robust approach for regional scale evaluation of groundwater discharge to large
lakes.
A renaissance in regional hydrogeology
Authors: Rudolph D L
Published: February 2019

Over the last five decades hydrogeologic research has evolved through a series of different core areas. The focus has changed based on significant scientific breakthroughs within the emerging discipline and on societal priorities that have influenced funding
opportunities. In recent years, significant attention and research activity have refocussed on regional groundwater assessment, one of the foundational topics in modern hydrogeology. This renewed emphasis is related to a deterioration in the apparent resilience of groundwater systems due to chronic
influences of legacy contaminants, overexploitation and increased variability within the water cycle. The recent water quantity crises in the USA and western Canada, and the Source Water Protection work underway in Ontario, have illustrated some of the significant impacts on regional groundwater
resources within the North American context. Emerging sensor technology, modeling platforms and increasing access to large data sets is enhancing the understanding of key processes and providing unprecedented quantitative insight within the entire hydrologic cycle at the watershed scale. Challenges
remain with the optimal integration of data streams into modeling platforms to ensure appropriate parameterization and minimize uncertainty associated with the results. In this presentation, the increasing emphasis on regional hydrogeologic assessment will be discussed within the context of how it
may influence the Government awareness and prioritization of groundwater in Canada as a strategic, economic and yet vulnerable resource.
Hydrogeological terrains and typical settings of southern Ontario
Authors: Sharpe D R , Piggott A
Published: February 2019

Groundwater is an important component of the hydrologic cycle of southern Ontario, which is significant to water supply and to groundwater discharge to surface water. To improve our understanding of groundwater, we develop a framework of typical terrains or
hydrogeological settings that use geologic and topographic controls to describe how water moves through the southern Ontario landscape. Surface sediment and bedrock types, permeability, physiography and topographic gradients yield distinctive regional hydrogeological settings. Hence, we review a
small number of hydrogeological settings, which contribute to a simple characterization of regional surface water and groundwater conditions across southern Ontario. Climate, stream and well monitoring data are integrated with local terrain information to assess the hydrological and hydrogeological
response of typical settings. In each setting, the movement of water has differences in fluxes and temporal patterns as it flows across the surface and through the subsurface. We describe seven hydrogeological settings: five in sediment (clay, sand, till upland, till complex, and gravel); and two in
bedrock. The selected hydrogeological settings characterize ~90% of all terrain at the regional scale based on a simplified geological map of southern Ontario. The identified settings cover large areas, and include several different sediment/ bedrock landscapes of the Paleozoic basin and
Shield margin. It is expected that the main hydrogeological characteristics and hydrologic behaviour of these settings are represented in the hydrograph trends for each terrain.
Effect Modification by Baseline Mortality in the MORDOR Azithromycin Trial
Authors: Oron Assaf P. , Burstein Roy , Mercer Laina D. , Arzika Ahmed M. , Kalua Khumbo , Mrango Zakayo , West Sheila K. , Bailey Robin L. , Porco Travis C. , Lietman Thomas M.
Published: February 2019

We examined whether baseline mortality risk, as a function of child age and site, modified the azithromycin mortality-reduction effect in the Macrolide Oraux pour Réduire les Décès avec un Oeil sur la Résistance (MORDOR) clinical trial. We used the Cox proportional hazards model with an interaction term. Three models were examined representing three sources for the baseline-risk covariate: two using sources external to MORDOR and the third leveraging data within MORDOR. All three models provided moderate evidence for the effect becoming stronger with increasing baseline mortality (P = 0.02, 0.02, and 0.07, respectively) at the rate of approximately 6–12% additional mortality reduction per doubling of baseline mortality. Etiological and programmatic implications of these findings are discussed.
Performance evaluation and optimization studies of border irrigation system for wheat in the Indian Punjab
Authors: Kaur Samanpreet , Raheja Amina , Aggarwal Rajan
Published: February 2019

Surface irrigation methods are the most widely practiced worldwide for irrigation of row crops. The major problem with these methods is low irrigation efficiency, mainly due to poor design. In the Punjab, border irrigation is used to irrigate wheat crops grown over 90% of the cultivated area. The evaluation of existing border systems using a surface irrigation model showed that the irrigation conditions, comprising of inflow rate, border dimensions, and cut-off time, were diverse in tubewell and canal irrigated areas. The study also examined the feasibility of optimizing border dimensions taking into consideration the existing irrigation conditions for achieving more than 60% application efficiency as compared to the 30–40% achieved under present field conditions. In the case of a border length of 60 m, it was recommended to increase border width in the range of 10–45 m and 20–60 m for different flow rates of 10, 20 and 30 L/s in light and medium soils, respectively. For higher flow rates, a border length ranging from 120–150 m was found to be optimum. For a border length of 150 m, it was recommended to keep a border width ranging from 4–38 m and 8–65 m in light soils and medium soils, respectively, for flow rates of 10, 20, 30 and 60 L/s. Optimizing border dimensions is a practical way to achieve efficient and judicious use of water resources.
Deterioration in the water quality of an urbanised estuary with recommendations for improvement
Authors: JB Adams , Pretorius L , Snow GC
Published: February 2019

Water quality characteristics of the heavily urbanised and industrialised Swartkops River and Estuary in the Eastern Cape have been the focus of several studies since the 1970s. Overloaded and poorly maintained wastewater treatment works (WWTWs), polluted stormwater runoff and solid waste have all contributed to the deterioration in the water quality of the river and estuary. The objective of this study was to determine the current water quality status of the Swartkops Estuary, by investigating spatial and temporal variability in physico-chemical parameters and phytoplankton biomass and where possiblerelate this to historical water quality data. The present study found evidence suggesting that water is not flushed as efficiently from the upper reaches of the estuary as was previously recorded. Reduced vertical mixing results in strong stratification and persistent eutrophic conditions with phytoplankton blooms (> 20 μg chl a·L−1), extending from the middle reaches to the tidal head of the estuary. The Motherwell Canal was and still is a major source of nitrogen (particularly ammonium) to the estuary, but the Swartkops River is the primary source of phosphorus with excessive inputs from the cumulative effectof three WWTWs upstream. An analysis of historical water quality data in the Swartkops Estuary (1995 to 2013) shows that all recorded dissolved inorganic phosphorus measurements were classified as hypertrophic (> 0.1 mg P·L−1), whereas 41% of dissolved inorganic nitrogen measurements were either mesotrophic or eutrophic. If nutrient removal methods at the three WWTWs were improved and urban runoff into the Motherwell Canal better managed, it is likely that persistent phytoplankton blooms and health risks associated with eutrophication could be reduced.
Foliar nitrogen dynamics of an invasive legume compared to native non-legumes in fynbos riparian zones varying in water availability
Authors: Crous Casparus J , Drake Deanne C , Jacobsen Anna L , Pratt R Brandon , Jacobs Shayne M , Esler Karen J
Published: February 2019

The legume Acacia mearnsii invades South Africa’s fynbos riparian zones and may alter the nitrogen (N) dynamics and supply in these areas that typically support few native N fixers. Nitrogen uptake by A. mearnsii may also be influenced by water availability, potentially affecting riparian-specific performance and impact estimations. We expected to find functional differences between the invasive legume and the two co-occurring but non-leguminous native species Brabejum stellatifolium and Metrosideros angustifolia. We also wanted to examine whether in-situ water availability affected N source or uptake inthe invasive species. We found A. mearnsii was indeed functioning differently from non-N-fixing native species, and had considerably higher foliar %N. Interestingly, 15N abundance and uptake were associated with site hydrology, meaning water availability should be scrutinised when assuming N-fixing in A. mearnsii using δ15N. Nonetheless, higher water availability to A. mearnsii in fynbos riparian ecosystems did increase foliar N uptake. This has implications for prioritizing clearing of sites with increased nutrient deposition, such as dense stands in relatively moist riparian zones.
Model test and numerical investigation of the effect of the impervious layer’s slope on seepage characteristics under hydraulic structures
Authors: Ghobadian Rasool , Shekari Hamed , Koochak Parisa
Published: February 2019

Although the impervious layer under a hydraulic structure is rarely flat, the effect of the impervious layer’s slope, under the hydraulic structure, on seepage characteristics has not been studied to date. Therefore, this study investigated the effect of the downhill and uphill impervious layer’s slope (downhill/uphill foundation slopes) on the uplift pressure, seepage discharge and exit gradient under hydraulic structures. In order to reach this goal, a numerical model has been developed in which the general equation of fluid flow in non-uniform; anisotropic soil is solved by the finite volume method on a structured grid. The model validation was performed using the measured data from experimental tests. The results of the model validation indicated that the model calculates the seepage discharge and uplift pressure with a maximum error of less than 3.79% and 3.25%, respectively. The results also indicated that by increasing the downhill foundation slope (DFS) the uplift force decreases, but the exit gradient and seepage discharge increase. Moreover, by increasing the uphill foundation slope (UFS), the uplift force increases but the exit gradient and seepage discharge decrease. In addition, the results demonstrate that by increasing the length of the cut-off wall the effect of the DFS on decreasing and UFS on increasing the uplift pressure force becomes more severe. However, the effect of the DFS on increasing the seepage discharge and UFS on decreasing the seepage discharge becomes milder as the length of the cut-off wall increases. By increasing the DFS, from zero to −15%, the exit gradient increases 19.75% and 14.4% for 1 m and 6 m cut-off lengths, respectively.