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In this paper we analyze the discourse-pragmatic use of the adverbs there/here , e.g., " So, our grandson there is a real mixture ", in four small northern Ontario towns. 1200 examples contrasted by type of reference, ambiguous locative or non-locative, were coded for social and linguistic factors and analysed using statistical modelling. The results reveal that the strongest predictor of discourse-pragmatic use is date of birth: middle-aged speakers use it most in each town, but no other social factors (e.g. perceived gender, education, job type) are significant. Importantly, the higher the proportion of Francophone populations in the community, the greater the use of there but not here. We argue that alignment between Francophones and Anglophones is a likely explanation. More generally this study highlights the value of discourse-pragmatic features for understanding styles of interaction and underscores the research potential for comparing these phenomena across communities. • Discourse-pragmatic there/here is a vernacular feature of northern Ontario. • Strongest predictor of use is date of birth: middle-aged speakers use it most. • More French heritage individuals in a community correlates with greater usage. • Heightened use is emblematic of alignment between Francophones and Anglophones as defined and reported in the discourse-pragmatic and sociolinguistic literature. [ABSTRACT FROM AUTHOR]

Abstract River ice breakup and resulting flood risk is a nearly annual concern for communities along the five major rivers draining to the James and Hudson Bay Coasts in Ontario (Moose, Albany, Attawapiskat, Winisk and Severn Rivers). Ice breakup within this region has historically been monitored using flight reconnaissance supplemented by assessment of hydrometric data. More recently, remote sensed imagery have been used to monitor near real-time ice breakup and flood risk. However, the near real-time remotely sensed breakup information was found to have limited utility in the absence of a broader spatial and temporal understanding of breakup progression. The primary purpose of this study was to develop a method for generating a dataset of breakup dates. A secondary objective was to calculate statistics from this dataset that can be used to provide context to operational near real-time imagery analysis and improve understanding of ice processes in the study area. An automated method for detecting river ice breakup dates from 2000 to 2017 using MODIS imagery was developed. This method uses a threshold-based technique that aims to maximize river coverage and minimize effects of cloud obstruction. Image processing was completed in the high-performance Google Earth Engine application which enabled iterative classification and model calibration. The breakup date dataset was used to calculate statistics on breakup timing, duration, annual variability and breakup order. An assessment of patterns within these data is discussed, relationships between breakup timing, duration and highwater years is explored and the operational utility of these statistics is described. The classification compared well with Water Survey of Canada derived breakup dates with mean bias ranging from −2.0 days to 6.7 days and mean absolute error of 3.4 days to 6.9 days across the rivers. Latitude and distance upstream were found to be primary controls on breakup timing with drainage network configuration and reach morphology also having an influence. No relationships between highwater years and calculated breakup statistics were found. It is recommended that future studies use the dataset developed in this study in combination with hydrometric and remotely sensed data to improve prediction of highwater and understanding of breakup processes within these rivers. Highlights • Derive ice breakup dates from MODIS leveraging the rapid processing of GEE • Calculate range of breakup dates, duration, annual variability and sequence • Latitudinal and downstream breakup trends are observed with notable exceptions. • Demonstrate utility of results for informing operational flood monitoring [ABSTRACT FROM AUTHOR]

In North American boreal forests, woody biomass is increasingly becoming an attractive bioenergy feedstock as it represents a more renewable, and low carbon alternative to fossil fuel. However, concerns over the ecological sustainability of an intensification of biomass harvesting over the long term remain. We assessed the effects of a gradient of biomass removal established 20 years ago in five jack pine ( Pinus banksiana ) stands across northeastern Ontario on the taxonomic and functional structure of ground-dwelling Collembola and Oribatida communities. Essential to soil functioning, these two major taxa of mesofauna are dependent on microhabitats and food supply such as fungi provided by woody debris. Three treatments were considered including stem-only harvesting, whole-tree harvesting (stem, tops and branches removed), and blading (whole-tree harvesting plus removal of stump and forest floor). Adjacent uncut mature (±90 year-old) stands were considered as reference state conditions ( i.e. the endpoint of stand development following stand replacing disturbance). Soil mesofauna were collected and environmental variables measured across all treatments. We identified species of both taxa and measured a suite of functional response traits such as body length and reproduction strategy. Compared to mature uncut forests, soil mesofaunal communities remained modified 20 years after biomass harvesting, notably in the most intense practice (blading). Treatment effects were more evident in Oribatida communities both taxonomically (lower density, biomass, species diversity and shifted composition) and functionally (lower diversity and modified trait composition resulting from fewer surface-dwelling, fast-dispersing and micro-detritivorous species) than in Collembola communities. This taxa-specific response may reflect generally shorter lifespans, higher reproduction rates and faster dispersal of Collembola than Oribatida. Incomplete recovery of mesofauna was consistent with persistent modifications of soil environmental conditions in harvested plots, notably after blading. Modifications included a reduced organic cover (ground vegetation, mosses and woody debris) as well as lower organic soil thickness and moisture, which likely resulted in fewer suitable microhabitats for many species. Using complementary taxonomic and trait-based approaches to highlight the underlying mechanisms of mesofaunal responses, our study revealed that recovery is incomplete within 20 years after intensive biomass removal in these boreal conifer-dominated stands, and is likely linked to stand development and associated processes. As a result, longer-term monitoring will be required to track mesofaunal community recovery through these later developmental stages. [ABSTRACT FROM AUTHOR]

Growth–climate relationships of trees are species-specific and can vary over space and time. Here, we study red pine ( Pinus resinosa Ait.) by analyzing tree-ring width data from 37 sites across northern Ontario, Canada for the period 1901–2010. We performed response function and moving response function analyses using seasonal data of three climatic variables: precipitation, minimum temperature and maximum temperature. Our analyses show considerable spatial and temporal variability in red pine growth response to climate during the 20th century. In general, red pine growth responses to climate were more significant in northwestern Ontario than in northeastern Ontario. Overall, precipitation was the most significant predictor of red pine growth, with seasonal variations across sites. Unlike many other studies, we did not find any significant growth response to current year summer temperature. Instead, at many sites in northwestern Ontario, red pine had a significant negative growth response to prior summer temperatures. The results of canonical correspondence analysis show that red pine growth response to climate follows a longitudinal gradient. Temporal stability analyses revealed that growth–climate response of red pine at any site was not stable during the 20th century. We observed a general shift from significant growth response to seasonal temperature during the first half of the 20th century to significant growth response to seasonal (except for spring) precipitation during recent decades. The spatial and temporal variability of red pine growth response to climate detected in our study should be considered in future plans for forest management of this species and can also be used for better understanding forest ecological dynamics at the regional scale for conservation purposes. [ABSTRACT FROM AUTHOR]

This study examines the public education practices of emergency management practitioners in small communities in rural Northern Ontario. The strengths and challenges associated with those practices are investigated in order to develop effective strategic and tactical best practice recommendations for public hazard risk communication and disaster risk reduction (DRR) education. Municipalities involved in this research were selected according to geographic location (Northern Ontario) and population size (<10,000 residents). The findings reveal that the most significant challenges are associated with role sharing and include a lack of resources, both human and financial, and correlated time management pressures while the strengths include strong community cohesion and an embedded culture of emergency preparedness. The paper concludes by recommending the following best practices: 1) build on existing strengths in rural communities to increase DRR, 2) mimic the fire prevention education strategy, 3) use available media venues to their maximum potential, 4) develop targeted DRR public education through collaborative partnerships, 5) create partnerships with local organizations to assist in DRR public education, 6) deploy municipal disaster and emergency management (DEM) education responsibilities in a way that minimizes the impact of role sharing, 7) adjust legislation and the role of provincial/state level emergency management agencies to accommodate the needs of rural communities. [ABSTRACT FROM AUTHOR]

Highlights: [•] The cover of Canada yew can be predicted using landscape-scale indicators. [•] Random Forests analysis produced a model predicting Canada yew cover with a root mean square error of 9.2%. [•] In the boreal forest of Ontario, the proportion of Balsam Fir in the canopy was the strongest indicator of Canada yew cover. [•] The relationship is likely the result of both species affinity for habitats that have experienced a long time period without major disturbance. [Copyright &y& Elsevier]

Highlights: [•] A low salvage removal was conducted in blowdown aspen stands, northeastern Ontario. [•] The salvage increased density, but not average height of aspen suckers. [•] Mechanical operations during salvage destroyed advanced conifers. [•] Windrowing before planting slightly reduced the cover of downed wood. [•] Chemical tending reduced broadleaves and shrubs and increased conifers and grasses. [ABSTRACT FROM AUTHOR]

Northern peatlands (those located in boreal and subarctic regions) are important components of global soil organic carbon (C) stock. Moreover, they are located in regions witnessing rapid changes in climate and becoming intensely scrutinized for industrial development and alternative energy generation. However, peat C stock is highly variable and little is known about its variability especially among peatland types. This is an issue because it makes the monitoring of peatland carbon stock complicated especially with the changing climatic conditions. Furthermore, it limits the opportunities to successfully estimate peatland C stock across regional scales. We estimated peat C stock using data from 1982 to 1985 from Ontario Geologic Survey field study of peatlands distributed across twelve sites in northern Ontario. Carbon stock (kgCm−2) was estimated using the equation: carbon concentration on gravimetric basis×bulk density×peat depth. The peat sampling depth was about 1m and had a total data point of around 203 points. Treed fens had the highest mean C stock±SE of 223±31kgCm−2 while open bogs had the lowest mean C stock±SE of 157±7kgCm−2. Mean C stock also varied among peatlands at regional level with the inter-quartile range of about 72–73kgCm−2 for open bogs and fens; and around 94–141kgCm−2 for treed bogs and fens respectively. Minimum detectable differences in C stock were also large, ranging from 50 to 113kgCm−2 for bogs and fens, respectively. The required sample size to detect 20% change in peat C at a power of 70% was more than double (212 plot) for fens than the number of sample plots (82) surveyed. This implies more sample size and information for fens is needed. This could potentially be achieved by the use of geospatial technology in deriving peatland biophysical information. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: To review the outcomes of supraglottoplasty performed in children with severe laryngomalacia at a pediatric university teaching hospital and to determine if these outcomes are influenced by gender, age at time of supraglottoplasty, or medical comorbidities. Methods: Retrospective chart review of children who underwent supraglottoplasty for severe laryngomalacia between 2001 and 2010 at the Children's Hospital of Eastern Ontario in Ottawa, Canada. Statistical significance was obtained using 2-tailed Fisher's exact test. The outcome measures were resolution of laryngomalacia symptoms or persistence of laryngomalacia symptoms with or without additional surgery. Results: Among 26 post-primary supraglottoplasty patients, 46.2% had resolution and 53.8% had persistence, including 19.2% with partial improvement and 34.6% requiring revision supraglottoplasty and/or tracheostomy. Resolution was present in 35.7% of males and 58.3% of females (p =0.43); in 33.3% of all patients ≤2 months old and 52.9% of all patients >2 months old (p =0.43); and in 50.0% of non-comorbid patients ≤2 months old and 80.0% of non-comorbid patients >2 months old (p =0.52). 71.4% of persistence cases were found in comorbid patients. 83.3% of comorbid patients had persistence, compared to 28.6% of non-comorbid patients (p =0.008). Of the 3 patients with overlapping comorbid categories, 2 required at least 2 revision supraglottoplasties and ultimately required a tracheostomy. Conclusions: Persistence of laryngomalacia symptoms post-primary supraglottoplasty was not associated with gender or age at time of surgery, and was more commonly found in children with comorbidities. Patients with coexisting medical conditions appear to require more aggressive surgical management, beyond one revision supraglottoplasty. [Copyright &y& Elsevier]

Abstract: Much of the mercury (Hg) in freshwater fish of the boreal shield ecoregion is believed to originate from atmospheric deposition. As such, declines in fish Hg concentrations would be expected in response to recent declines in atmospheric Hg deposition in this ecoregion. We compared recent (2005–2010) and historic (1974–1981) muscle total mercury concentrations ([THg], standardized to a fish body mass of 1kg) in seven fish species (five piscivores, two benthivores) from 73 lakes in northern Ontario (Canada) using a paired-comparisons approach. The rate of bioaccumulation (i.e., slopes of loge[THg] vs loge total length relationship) increased for walleye (Sander vitreus) but did not change significantly for any other species. There was no significant decline in mean [THg] between recent and historic time periods for any species. In fact, recent mean [THg] were slightly higher (<0.08ppm) than historic mean [THg] for all species, and this difference was significant for northern pike (Esox lucius). The magnitude of the temporal change in northern pike declined significantly from south to north over the study area but there were no discernible geographic patterns in the temporal change in [THg] for any other species. This study shows that [THg] of most large-bodied fish species in boreal shield lakes are not declining in response to the decline in atmospheric Hg deposition. [Copyright &y& Elsevier]

Abstract: The procurement of logging residue for energy production can be uneconomical due to high moisture content and low gross calorific value. High moisture content in biomass lowers the energy density and transportation becomes less efficient. Logging residue, from full tree logging operations stored in roadside beehive and windrow piles, were examined to determine the effect of storage method and duration on fuel quality in northwestern Ontario, Canada. The fuel attributes assessed were moisture content, gross calorific value and ash content. Windrows displayed lower moisture content than beehives. Softwoods generally displayed lower moisture content and higher gross calorific values than hardwoods. Smaller diameter stems displayed higher gross calorific value and ash content than larger diameter stems. The moisture content (green basis) reduced from a green state to 15.1% after two years of storage in roadside slash piles, whereas gross calorific value and ash content did not change significantly with storage time. The gross calorific values ranged from 19.5 to 23.1 MJ kg−1 and the ash content ranged from 0.4% to 8.4% for all species, components and storage years. The study demonstrates that the storage regime plays a significant role on the fuel quality of logging residue. Proper storage and drying techniques improve the fuel quality and net energy yield from logging residue biomass, thereby leading to an overall cost reduction of the biomass feedstock. [Copyright &y& Elsevier]

Abstract: We previously investigated the responses of forest birds to habitat changes 1–7years post-harvest in three northern Ontario tolerant hardwood forest stands cut under the selection system. The same three cut blocks and a control area were re-sampled in 2009, 10–12years post-harvest, to compare community composition, total and species abundances and species richness. We found that the breeding bird communities of the selection cut blocks had not fully recovered 10–12years post-harvest. Veery, Chestnut-sided Warbler, Magnolia Warbler, American Redstart and Mourning Warbler numbers were elevated in all three cut blocks, and White-throated Sparrow numbers were elevated in two of the three cut blocks, 10–12years post-harvest. In contrast, Ovenbird numbers remained depressed in two cut blocks 10–12years post-harvest. Overall, species richness remained high in all three cut blocks, even though total abundance declined. The data suggest that repeated applications of selection cutting could have long-term, cumulative effects on forest bird communities. [Copyright &y& Elsevier]

Abstract: Individual-tree distance independent diameter growth models were developed for black spruce and jack pine plantations. Data used in this study came via stem analysis on 1170 black spruce (Picea mariana [Mill.] B.S.P.) and 800 jack pine (Pinus banksiana Lamb.) trees sampled from 75 stands of 25 even-aged monospecific plantations for each species in the Canadian boreal forest region of northern Ontario. Of the 75 stands, 50 were randomly selected for each species and all trees from these stands were used for model development. Trees from the remaining stands were used for model evaluation. A nonlinear mixed-effects approach was applied in fitting the diameter growth models. The predictive accuracy of the models was improved by including random effects coefficients. Four selection criteria – random, dominant or codominant, tree size close to quadratic mean diameter, and small sized – were evaluated for accuracy in predicting random effects for a new stand using the developed models. Random effects predicted based on trees selected using the random selection criterion provided more accurate diameter predictions than those using trees obtained via other selection criteria for both species. The models developed here are very important to forest managers as the diameters predicted by these models or, their stand-level summaries (i.e., basal area, average diameter), are used as inputs in any forest growth and yield models. In addition, individual-tree diameter growth models can be used to directly forecast changes in diameter distribution of stands. [Copyright &y& Elsevier]

Abstract: Overstory mortality, understory tree recruitment, and vegetation development were assessed in trembling aspen (Populus tremuloides Michx.) stands following two recent episodes of forest tent caterpillar defoliation (Malacosoma disstria Hbn.) in northeastern Ontario. The results suggest that poplar (aspen and balsam poplar (Populus balsamifera L.)) mortality increased with consecutive years of insect defoliation occurring from the mid-1980s to mid-2000s and the proportion of poplars in the overstory, but decreased with improved pre-defoliation tree vigour (DBH increment). The first outbreak, which lasted from the mid-1980s to early 1990s, was more severe in terms of insect defoliation and contributed more to poplar mortality and decline. The decline began in the late 1990s and peaked in early 2000s. Poplar regeneration and understory shrubs responded rapidly to foliage loss to insect defoliation and mortality of overstory poplars. The regenerated poplars were able to maintain their growth under developing shrubs and residual overstory canopy and numbers were sufficient to compensate for the poplar trees lost to insect infestation. The defoliation-induced overstory decline will accelerate the transition of aspen stands to conifer dominance through enhanced conifer recruitment and growth, and reduced hardwood overstory in aspen-dominated stands, while hardwood dominance will persist in pure aspen stands. From a timber supply perspective, the decline caused by forest tent caterpillar defoliation could delay the availability of aspen stands for harvesting by 40–50 years. [ABSTRACT FROM AUTHOR]

Abstract: Background: The relationship between smoking and breast cancer remains controversial. The study aim was to assess the relationship of passive and active smoking to breast cancer risk by N-acetyltransferase 2 (NAT2) phenotype, using a comprehensive assessment of both passive and active smoking. Methods: We undertook a population-based case–control study in Northeastern Ontario, Canada of 347 women diagnosed (2002–2004) with breast cancer and 775 population-based controls. The mailed study package included a questionnaire requesting information about established breast cancer risk factors, passive and active smoking, and a buccal swab for genetic analyses. Results: Among never-active smokers, a long duration of passive smoking was associated with an increased risk of breast cancer (odds ratio (OR) 1.86 (95% confidence interval (95% CI) 1.01–3.44) (test for trend (p =0.07)); that risk was more elevated for NAT2 slow acetylators (OR 2.76, 95% CI 1.16–6.59) (and highest in extremely slow acetylators), but not elevated for NAT2 fast acetylators (OR 1.17, 95% CI 0.42–3.23). Among active smokers more than 20 pack-years of smoking was associated with an OR of 1.34 (95% CI 0.92-1.96); more elevated among NAT2 fast acetylators OR 1.93 (95% CI 1.01–3.69) but not elevated among NAT2 slow acetylators. Women who were NAT2 fast acetylators in the highest quartile for duration of active smoking had an OR of 2.74 (95% CI 1.42–5.27), with a significant test of trend (p =0.005). Conclusions: These findings suggest that passive and active smoking may be related to breast cancer, and the effect may be differentially modified by NAT2 phenotype. Further research into the genetic modification of a breast cancer–smoking relationship may help to reconcile earlier discrepant findings. [Copyright &y& Elsevier]

Abstract: This paper describes the use of population attributable risk percent (PAR%) in the study of morbidity and mortality clusters, and in particular, shows how this method of risk characterization can usefully distinguish between multiple geographic clusters of potential interest. Incident lung cancer data in persons 60 years and over from the province of Ontario, Canada, are analyzed for spatial clusters, and each cluster is characterized in terms of statistical significance, relative risk and PAR%. We observe that although relative risk is probably highest in Northern Ontario, highest PAR% is in Eastern Ontario, and in particular, the Ottawa area. These results illustrate the usefulness of attributable risk as a metric to help characterize and understand spatial clusters, which could be important for place-based public health interventions. [Copyright &y& Elsevier]

Abstract: The long-term stability of paper sludge amendments as covers for reclaimed mine waste storage facilities must be assessed by the mining industry. This study examines a 6 yr old sequence of paper sludge amendments applied over wastes from historic Au mines located in Northern Ontario, Canada. As paper sludge is mostly comprised of C-rich organic compounds, elemental quantification, 13C cross polarization/magic angle spinning nuclear magnetic resonance (13C CP/MAS NMR) spectroscopy, and Fourier transform infrared (FTIR) spectroscopy were used to examine the minimal changes in the C content and speciation observed of the amendments over time. These results suggest that paper sludge covers are suitable for use in medium to long-term mining reclamation strategies. [Copyright &y& Elsevier]

Abstract: Long-term forest fire regime was simulated for the Moose River Forest Management Unit (FMU) in northeastern Ontario. The simulated area has not been managed for timber production and fire suppression activity has been minimal. The available data included fire records for 1970–2006 and forest age structure from forest resource inventory completed in 1978. The fire regime was simulated using a simple percolation model driven by three parameters: probabilities of fire spread during low and high fire activity years and of a given year being a low fire activity year. The model successfully generated a long-term fire regime producing age structure and 37-year-long fire records similar to those observed for the Moose River FMU. The simulation results suggest that (a) fire return interval in northeastern Ontario is likely much shorter than indicated by estimates based exclusively on data from the last four decades of fire activity, and (b) it is possible that the fire regime in northeastern Ontario has not changed since mid-1800s but rather is characterized by relatively long periods of low incidence of fire interspersed with pulses of high fire activity. [Copyright &y& Elsevier]

Abstract: The Victor Northwest (VNW) kimberlite is one of several steep-sided pipes in the Victor kimberlite complex. In this paper detailed logging of ~4.2km of drill core and petrographic studies of hundreds of samples and thin sections are used to reconstruct the intra-crater stratigraphy of the VNW kimberlite and to constrain the emplacement history of the pipe. The results show that the VNW pipe comprises numerous contrasting small-volume volcanic facies, including dark and competent kimberlite, sedimentary country rock breccias, pyroclastic kimberlite and resedimented volcaniclastic kimberlite. We interpret that the VNW pipe was formed by two separate eruption cycles. During the first eruption cycle, the main VNW crater is excavated and partly filled. The second eruption cycle excavates a smaller nested crater within the existing lithified pipe fill. Both eruption cycles can be subdivided into three comparable stages. The first stage in both cycles comprises a highly explosive eruption involving crater excavation and deposition of pyroclastic kimberlite. The eruption products contain abundant broken olivines, small angular country rock fragments and kimberlite ash. All these features indicate high degrees of fragmentation resulting from high eruption intensities. The high proportion of country rock fragments in these deposits suggests continuous pipe wall erosion. The second stage in both cycles is represented by dark and competent deposits, which have low country rock fragment abundances and mostly intact olivines. Based on contact relationships and textures within these units it is suggested that these rock types are formed by lower energy eruptions, during which no major pipe wall erosion took place. The eruption came to an end during the third and last stage. In both cycles, the uppermost deposits record resedimentation of kimberlite by water. Major pipe wall collapse results in the formation of voluminous sedimentary country rock breccia deposits that cap all previous deposits. [Copyright &y& Elsevier]

Abstract: The adaptation of a national/continental-scale model of carbon uptake to the local-scale using highly detailed airborne discrete lidar and hyperspectral data was investigated at a boreal forest mixedwood site in northern Ontario. Spatially explicit maps of canopy chlorophyll concentration and the fraction of photosynthetically active radiation absorbed by the canopy (FPAR) under direct and diffuse radiative conditions were developed for five time periods in 2004 (i.e., winter (January 1–May 31), leaf-out (June 1–20), summer (June 21–July 31 and August 1–31) and senescence (September 1–30)). The maps were used in conjunction with meteorological measurements, such as incident total and diffuse PAR, global solar radiation, and air temperature, taken on a flux tower which is located at the center of the study. Distinct spatial patterns in FPAR, a result of changes in canopy chlorophyll concentration, are increasingly evident throughout the season because of the variation in species groupings within the 1-km radius surrounding the flux tower. In general, the model shows a good correlation to flux-tower-measured gross ecosystem productivity (GEP) (r 2 =0.70 for 10-day averages throughout the year), with the largest deviations occurring in June–July. Species-level data shows the influence of a large homogenous patch of black spruce on the tower measured GEP and demonstrates the contribution of white birch, by far the most dominant species, to the total GEP for the area. [Copyright &y& Elsevier]

Abstract: Recently discovered horizons of non-deformed felsic welded crystal tuff in the Proterozoic rift system of northern Ontario yield a geologically stable paleomagnetic vector. Using alternating field (AF), thermal (TD) and low-temperature demagnetization (LTD) techniques, a single stable characteristic remanence (ChRM) vector is found in all specimens (declination/inclination=115°/−73.5°; α 95 =2.1°, n =58). It is overprinted by a Bruhnes’ epoch VRM. The tuffs paleopole position coincides with that of ubiquitous sub-horizontal diabase sheets which intruded at ∼1110Ma during Late Proterozoic Keewanawan Volcanism. The latter produced numerous volcanic and intrusive rocks along the margins of the Lake Superior paleo-rift system, during the interval 1087–1120Ma, but the sills are most extensive. Although the Voosges Lake Tuff shares the same paleopole location as the diabase sheets (1109Ma), the nearby Seagull pluton (1112Ma) and the Keweenawan volcanic rocks, its primary zircons yielded a Mesoproterozoic crystallization age of 1542±3Ma. This is similar to the nearby English Bay felsic intrusions dated at [Davis, D.W., Sutcliffe, R.H., 1985. U-Pb ages from the Nipigon “Plate” (sic) and northern Lake Superior. Geol. Soc. Am. Bull. 96, 1572–1579]. Whereas the paleomagnetic magnetic signal appears primary in the 1542Ma Voosges Tuff, it was completely reset by the Late Proterozoic Keewanawan paleofield (∼1100Ma). The Tuff units are separated from the diabase sills by stratigraphic thicknesses of ≤50m and show no traditional petrographic evidence of annealing or thermal metamorphism. Since it is improbable that the 1542Ma tuff returned to the same paleolatitude at 1109Ma, we postulate that metasomatic processes caused a ∼1109Ma remagnetization. A similar event could explain unusual ChRMs reported for certain other pre-Keweenawan Proterozoic sites with adjacent Keewanawan diabase sheets. For example, some paleopoles reported for the Gunflint Formation (1878Ma) and Sibley Formation (>1339Ma, perhaps ∼1537Ma by association with the English Bay intrusions) might have been acquired due to secondary remagnetization. [Copyright &y& Elsevier]

Abstract: By using unusual combinations of demagnetization techniques, Proterozoic paleomagnetic vectors and paleopoles are provided for two recently discovered post-tectonic Proterozoic units near Armstrong, northern Ontario, and also for well-dated Gunflint Formation, which by previous techniques yielded problematical paleomagnetic data. The first paleomagnetic data are provided also for the Seagull Pluton and Inspiration Sills. Characteristic remanent magnetizations (ChRM) for the Pillar Lake Lavas indicate a Keweenawan age, more specifically ∼1000–1040Ma by comparison with the well-established APWP for the Late Proterozoic Superior craton. Four combinations of demagnetization techniques yield declinations in the range 108–133° and inclinations in the range −65 to −70° (n =100), which define paleopoles near 200W/48N corresponding to a location on the Keweenawan APWP near ∼1040Ma. In the underlying basement a recently discovered Proterozoic igneous complex, the Waweig Troctolitic Complex, yields new paleomagnetic data with declination and inclination 42/−54 (n =14) defining a paleopole at 238W/09N. Its ages may be 1400–1600 or ∼2000Ma by comparison with the presently available, ambiguous and sparsely populated APWP. The first paleomagnetic results for the Seagull Pluton (U–Pb age 1113Ma) yield a mean declination of 87.4/−75.7 (n =32) corresponding to a Keweenawan paleopole near 233/42N, consistent with other paleopoles near ∼1200Ma. Tuffs of the oft studied but problematical Gunflint Formation (U–Pb age1878Ma) yielded stable and presumably primary vectors using several different demagnetization techniques on the same specimens. Their mean primary declination and inclination ∼303/+48.8 (n =17) yields a paleopole now located near 178W/42N, comparable with the published locations of paleopoles of ∼2000Ma. Of broader interest, we recognized that low temperature demagnetization preceding conventional demagnetization techniques enhanced the isolation of characteristic vectors. Combining the conventional techniques (thermal and AF demagnetization) also improved the resolution of characteristic vectors not achieved by other means. Low grade metamorphism affected the non-tectonized Proterozoic cover to the Canadian shield, due to burial or hydrothermal effects, obfuscating or erasing primary vectors in some lithologies and especially at certain sites. [Copyright &y& Elsevier]

In Canada rural and northern communities, particularly Indigenous communities, face challenges disproportionate to their urban counterparts in accessing health care services. Existing health research on rural communities has tended to emphasize and reinforce the rural/urban dichotomy in access to and delivery of services, leaving the notion of "rural" as an under-interrogated concept. Drawing on a qualitative study of health care providers, community members, and Indigenous Elders, we explore Indigenous people's beliefs about vaccination to complicate notions of rurality in order to illuminate the ways in which space and settler colonialism both shape and limit choices around health care access. [ABSTRACT FROM AUTHOR]