Search Results (31)

This study analyzes cancer trends in Canada using machine learning techniques to extract insights from extensive cancer data sourced from the Canadian Cancer Society and Statistics Canada. It aims to enhance the understanding of cancer epidemiology and inform better prevention, diagnosis, and treatment strategies. Data preprocessing addressed issues like missing values and normalization, ensuring reliability. The findings indicate a steady increase in new cancer cases, with estimates reaching 248,700 in 2026, up from 244,000 in 2022. Male incidence rates are projected to rise slightly to 602.3 per 100,000, while female rates may decline to 530.6. Regions such as Alberta, British Columbia, Ontario, and Quebec show rising incidence rates, contrasted by declines in Newfoundland and Labrador, Nunavut, and Yukon. Notably, this research reveals significant increases in cancer cases among individuals aged 60 and older, particularly those 70+. The hybrid ARIMA-LSTM model demonstrated superior forecasting accuracy compared with the other selected models. These findings offer valuable insights for health policymakers and highlight the potential of machine learning in public health forecasting, providing a framework for future research in other disease areas. Full article

Imported, non-native honey bees and bumble bees threaten native pollinators by spreading pathogens (disease and parasites) and outcompeting native pollinators for nectar and pollen. We reviewed Canadian federal, provincial/territorial, and municipal legislation to find governance requirements that potentially reduce these threats. We classified the requirements as follows: tracking the number and location of honey bee hives (registry); controlling the spread of pathogens (registry with inspections, quarantines, and cleaning regimes); controlling the competition with native pollinators (limiting shared use of space); and making regulations applicable to all domesticated bees in addition to honey bees. Policies and regulations to control the competition from honey bees are generally lacking. So, we propose the concept of “foraging leases” to manage the location and duration of honey bee apiaries on public lands. Based on the identified requirements, we recommend amendments to the legislation in Yukon Territory, a jurisdiction that still has healthy native pollinator communities that pollinate various human food and medicine crops. Recommendations include tracking hives and their pathogen status with beekeeping regulations enabled by the Animal Health Act, controlling the use of imported bumble bees with changes to the Animal Protection and Control Act and/or the Wildlife Act, and restricting use of public lands for apiaries with the Public Lands Act. Full article

Abstract: Objectives: This study aimed to map the distribution of nephrolithiasis’ environmental risk factors (occupational heat and heavy metal exposure and ambient seasonal temperature) and to assess the correlations of these exposures with the best estimates of the reported nephrolithiasis incidence in Canada. Methods: The regional average heat burden was defined as the mean temperature in the hottest three months of the year for 2020, 2021, and 2022. The employment rates in the top five industries with occupational heavy metal (cadmium, lead, and arsenic) and heat exposure were obtained from the Statistics Canada 2021 database. Statistical significance was calculated based on the 95% confidence interval difference from the null hypothesis. Correlation analysis was performed between our rates of nephrolithiasis risk factors and previously published estimates of the stone incidence: kidney stone interventions and acute kidney stone event rates. Results: Lower-latitude provinces had higher overall mean temperatures in 2020 to 2022, with Ontario, Manitoba, and Prince Edward Island having the highest seasonal heat burdens, in this order. Nunavut had the lowest rate of occupational heat exposure, while the remaining regions had similar rates. Yukon, the Northwest Territories, and Nunavut had significantly higher rates of occupational heavy metal exposure compared to the remaining regions. The ambient temperature and occupation heavy metal and heat exposure showed no significant correlation with the estimates of the stone incidence. Conclusions: The occupational heat exposure was relatively similar between regions. Northern Canada had higher occupational heavy metal exposure compared to other regions. Occupational exposures and temperature variations were not associated with the nephrolithiasis incidence in Canada. Full article

Geologic understanding of the richly mineralized Dawson Range gold belt (DRGB) in the central Yukon, Canada is hindered by: (1) limited outcrop exposure due to thick soil cover; and (2) low resolution age-constraints despite a long history of porphyry Cu–Au–Mo deposit (PCD) exploration. Here, the well-preserved Klaza Au–Ag–Pb–Zn porphyry–epithermal deposit is used as a type-example of Late Cretaceous magmatic–hydrothermal mineralization to address the complex metallogeny of the DRGB. U–Pb zircon dating defines four magmatic pulses of Late Triassic to Late Cretaceous ages with the latter consisting of the Casino (80–72 Ma) and Prospector Mt. (72–65 Ma) suites. The Casino suite has five phases of intermediate-to-felsic calc-alkaline composition, correspond with older (77 Ma) porphyry mineralization, and displays evidence of magma mingling. The intermediate-to-mafic, slightly alkalic Prospector Mt. suite shows evidence of mingling with the youngest Casino suite phases, correlates with younger (71 Ma), intermediate-sulfidation epithermal and porphyry-type mineralization, and shoshonitic basalts of the Carmacks Group. Zircon trace element data suggest a common melt source for these suites; however, the younger suite records features (e.g., high La/Yb) that indicate a higher pressure melt source. The results from this study highlight the Prospector Mt. suite as a historically overlooked causative magma event linked to Au-rich PCDs in the DRGB and extends the temporal window of PCD prospectivity in this area. The transition from mid-Cretaceous Whitehorse suite magmas to Late Cretaceous Casino-Prospector Mt. suite magmas is proposed to reflect a transition from subduction to localized extension, which is becoming more recognized as a common characteristic of productive porphyry belts globally. Full article

The steep and unstable terrain found on debris-covered glaciers, rock glaciers, talus slopes, moraines and other proglacial features often make terrestrial ground-penetrating radar (GPR) surveys unsafe or cost-prohibitive. To address these challenges, this research introduces a novel approach for studying buried ice using multi-low-frequency drone-based GPR. Monostatic antennas of 50, 100, and 200 MHz were flown along a transect spanning a debris-covered glacier and an ice–debris complex at Shár Shaw Tagà (Grizzly Creek) in southwest Yukon, Canada. The drone-based results were compared to manual GPR at two locations along the transect. The two manual segments were conducted using the same radar system in a bi-static mode and included common mid-point (CMP) surveys. Overall, the drone-based radar successfully identified buried ice and enabled estimation of ice body thickness. Notably, CMP results confirmed layer characteristics and enabled depths to be measured across the entire drone-based transect. Discrimination of detail across a range of depths was made possible by comparing the three low frequencies, highlighting the possibility of using this method for future investigations of debris thickness in addition to quantifying buried ice. This study confirms the effectiveness of drone-based GPR combined with manual CMP for surveying ice beneath previously inaccessible terrain. Full article

This review paper investigates the landscape of wildfire-related studies with a focus on infrastructure and evacuations across Canadian provinces, revealing a predominant focus on Alberta, particularly after the 2016 Fort McMurray wildfire. The aftermath of this event has heightened attention to the unique challenges faced during evacuations, emphasizing the urgent need for heightened awareness and preparedness, especially in the vulnerable northern communities of Alberta. Studies beyond Alberta contribute to understanding Canadian wildfire dynamics. However, a noticeable research gap in British Columbia raises concerns about research prioritization and resource allocation despite heightened wildfire activity. The fact that some provinces are contributing less than 4.2%, such as Quebec, Saskatchewan, Ontario, Northwest Territories, Yukon, and the Prairies, might be attributed to regional variations influenced by historical wildfire frequency and population density. Thematic analysis categorizing studies into “community support/resilience”, “evacuation efficiency”, and “infrastructure protection/raising awareness” provides nuanced insights. The dominance of the “community support/resilience” category, comprising over 40% of studies, signifies a societal shift towards proactive community engagement. Balanced representation in the “evacuation efficiency” and “infrastructure protection/raising awareness” categories, each contributing over 29%, reflects a collective effort to glean lessons from past evacuations and enhance community preparedness. Temporal trends and thematic analyses spotlight a commitment to continuous improvement, adaptability to emerging challenges, and a growing recognition of the multifaceted aspects of wildfire management. The evolving emphasis on community involvement, responsiveness to changing evacuation dynamics, and heightened awareness of infrastructure protection underscores the proactive stance of the research community, providing insights for shaping future research priorities, policy frameworks, and community resilience strategies in the face of evolving wildfire threats in Canada. Full article

Surveillance of endoparasites at the host community level is rarely reported for ungulates. Yet, changes in the composition and abundance of species in ungulate assemblages, coupled with environmental and climate change, bring into focus the need for baseline data on endoparasite occurrence in host species at the community level. We investigated the prevalence and intensity of eggs of endoparasites in feces of a dynamic boreal ungulate community in Yukon, Canada, that included reintroduced bison (Bison bison), as well as introduced elk (Cervus canadensis), naturally colonizing mule deer (Odocoileus hemionus), and resident populations of caribou (Rangifer tarandus), moose (Alces americanus), and thinhorn sheep (Ovis dalli). We also examined the change in endoparasite prevalence and intensity in bison fecal samples collected eight years apart. The prevalence of eggs detected in feces differed across species for most endoparasite groups. We also provide new records of several endoparasites in novel hosts or new geographic records. We detected a substantially greater prevalence and intensity of trichostrongyle-type eggs in bison feces between samples collected eight years apart. Our data emphasize the need for targeted pathogen surveillance programs to monitor the movement of various ungulate and associated endoparasites. This is particularly pertinent since our data potentially supports evidence for the continued northward expansion and host switching of protostrongylid species, which may have health implications for animals at a new interface. Full article

This paper presents the extension of the monolayer snow model of a semi-distributed hydrological model (HYDROTEL) to a multilayer model that considers snow to be a combination of ice and air, while accounting for freezing rain. For two stations in Yukon and one station in northern Quebec, Canada, the multilayer model achieves high performances during calibration periods yet similar to the those of the monolayer model, with KGEs of up to 0.9. However, it increases the KGE values by up to 0.2 during the validation periods. The multilayer model provides more accurate estimations of maximum SWE and total spring snowmelt dates. This is due to its increased sensitivity to thermal atmospheric conditions. Although the multilayer model improves the estimation of snow heights overall, it exhibits excessive snow densities during spring snowmelt. Future research should aim to refine the representation of snow densities to enhance the accuracy of the multilayer model. Nevertheless, this model has the potential to improve the simulation of spring snowmelt, addressing a common limitation of the monolayer model. Full article

The Arctic is experiencing the greatest increase in air temperature on Earth. This significant climatic change is leading to a significant positive trend of increasing wave heights and greater coastal erosion. This in turn effects local economies and ecosystems. Increasing wave energy is one of the main drivers of this alarming trend. However, the data on spatial and temporal patterns of wave heights in the Arctic are either coarse, interpolated or limited to point measurements. The aim of this study is to overcome this shortcoming by using remote sensing data. In this study, the Synthetic Aperture Radar (SAR) satellite TerraSAR-X (TS-X) and TanDEM-X (TD-X) imagery are used to obtain sea state information with a high spatial resolution in Arctic nearshore waters in the Canadian Beaufort Sea. From the entire archive of the TS-X/TD-X StripMap mode with coverage around 30 km × 50 km acquired between 2009 and 2020 around Herschel Island, Qikiqtaruk (HIQ), all the ice-free scenes were processed. The resulting dataset of 175 collocated scenes was used to map the significant wave height ($H_s$) and to link spatial and temporal patterns to local coastal processes. Sea state parameters are estimated in raster format with a 600 m step using the empirical algorithm CWAVE_EX. The statistics of the $H_s$ were aggregated according to spatial variability, seasonality and wind conditions. The results show that the spatial wave climate is clearly related to the dominant wind regime and seasonality. For instance, the aggregation of all the scenes recorded in July between 2009 and 2020 results in an average of 0.82 m $H_s$, while in October the average $H_s$ is almost 0.40 m higher. The analysis by wind direction shows that fetch length and wind speed are likely the most important variables influencing the spatial variability. A larger fetch under NW conditions results in a mean wave height of 0.92 m, while waves generated under ESE conditions are lower at 0.81 m on average. Full article

Community-driven projects have characterized Helicobacter pylori (Hp) infection in Indigenous communities in the Northwest Territories (NT) and Yukon (YT), Canada. These projects address concerns about the frequent diagnosis of Hp infection among community members and its relation to gastric cancer deaths, perceived to occur with alarming frequency in this region. Projects included breath-test screening for Hp infection, gastroscopy with gastric biopsies, and treatment to eliminate Hp infection. Previous project results showed a high prevalence of stomach pathologies associated with increased cancer risk among Hp-positive participants at baseline. This analysis describes changes in precancerous gastric pathologies in project participants who had gastroscopy before baseline treatment during 2008–2013 and again in 2017. Throughout the study period, the same pathologist graded Hp density, active gastritis, chronic gastritis, atrophic gastritis, and intestinal metaplasia using the updated Sydney System. Of 310 participants from three communities with baseline pathology data, 69 had follow-up pathology data. Relative to baseline, the prevalence of Hp infection and precancerous gastric pathology was substantially lower at follow-up; most participants who were Hp-positive at baseline and Hp-negative at follow-up had reduced severity of active, chronic, and/or atrophic gastritis at follow-up. Though follow-up numbers are small, these results yield evidence that successful Hp treatment has the potential to reduce the risk of gastric cancer in Arctic Indigenous communities. Full article

Gišogenesis, otherwise known as secondary-xylem development, was investigated in an old-growth upland population of white spruce (Picea glauca (Moench) Voss) trees having morphologically diverse crowns and growing on a south slope north of East Fork Creek bordering never-glaciated Yukon Beringia. After tree felling, trunks were segmented into one-metre lengths. In the laboratory, widths of xylem layers were measured across the four cardinal directions at each height, followed by Pearson’s product momentum correlations to evaluate variation in historical gišogenetic vigour within and between trees. Substantial variation was found, and it cannot readily be explained in terms of differences in extrinsic environment. Physiological differences in intrinsic gišogenetic regulation within a genetically diverse population, comprising both refugia and recent recruits, is proposed as a probable explanation, thus emphasizing the individuality of each tree’s internal control over how it responds to the extrinsic environment. Further investigations within Yukon Beringia may yield insight into evolutionary diversification of gišogenesis. Full article

Terrestrial photographic imagery combined with structure-from-motion (SfM) provides a relatively easy-to-implement method for monitoring environmental systems, even in remote and rough terrain. However, the collection of in-situ positioning data and the identification of control points required for georeferencing in SfM processing is the primary roadblock to using SfM in difficult-to-access locations; it is also the primary bottleneck for using SfM in a time series. We describe a novel, computationally efficient, and semi-automated approach for georeferencing unreferenced point clouds (UPC) derived from terrestrial overlapping photos to a reference dataset (e.g., DEM or aerial point cloud; hereafter RPC) in order to address this problem. The approach utilizes a Discrete Global Grid System (DGGS), which allows us to capitalize on easily collected rough information about camera deployment to coarsely register the UPC using the RPC. The DGGS also provides a hierarchical set of grids which supports a hierarchical modified iterative closest point algorithm with natural correspondence between the UPC and RPC. The approach requires minimal interaction in a user-friendly interface, while allowing for user adjustment of parameters and inspection of results. We illustrate the approach with two case studies: a close-range (<1 km) vertical glacier calving front reconstructed from two cameras at Fountain Glacier, Nunavut and a long-range (>3 km) scene of relatively flat glacier ice reconstructed from four cameras overlooking Nàłùdäy (Lowell Glacier), Yukon, Canada. We assessed the accuracy of the georeferencing by comparing the UPC to the RPC, as well as surveyed control points; the consistency of the registration was assessed using the difference between successive registered surfaces in the time series. The accuracy of the registration is roughly equal to the ground sampling distance and is consistent across time steps. These results demonstrate the promise of the approach for easy-to-implement georeferencing of point clouds from terrestrial imagery with acceptable accuracy, opening the door for new possibilities in remote monitoring for change-detection, such as monitoring calving rates, glacier surges, or other seasonal changes at remote field locations. Full article

Sustainable development of Canada’s North requires an increased focus on renewable, zero-emission energy sources. Burwash Landing in Yukon is prospective for geothermal energy based on a high geothermal gradient, local occurrence of warm groundwater and proximity to the active, crustal-scale Denali fault. Uncertainties about the potential geothermal system include the nature and geometry of fluid pathways, and heat sources required to drive a hydrothermal system. In this study, we inverted three passive electromagnetic datasets—321 extremely low frequency electromagnetic, 33 audiomagnetotelluric and 51 magnetotelluric stations—to map the subsurface electrical structure to 8 km depth. Our new model reveals vertical conductive structures associated with the two main faults, Denali and Bock’s Creek, which we interpret to represent fluid-deposited graphite and hydrothermal alteration, respectively. Our model supports an interpreted releasing bend on the main Denali fault strand. This is associated with the deepest conductivity anomaly along the fault and potential for deeper penetration of fluids. Enigmatic conductive bodies from 1 to > 6 km depth are associated with intermediate to mafic intrusions. Fluids released from these bodies may advect heat and provide a possible heat source to mobilize hot fluids and sustain a geothermal system in the region. Full article

Upper Triassic carbonate platforms from the Panthalassa Ocean remain less-understood and less-studied than their Tethyan equivalents. This imbalance is largely due to the poorer preservation state of Panthalassan carbonate rock successions in terms of rock quality and depositional geometries, which prevents good appreciation of depositional systems. In this context, carbonate exposures from Lime Peak (Yukon, Canada) represent an outstanding exception. There, the remains of an Upper Norian Panthalassan carbonate platform are well-exposed, show remarkably preserved depositional geometries and overall superior rock preservation. In this work, we analyse the carbonates from the Lime Peak area with particular attention to the vertical and lateral distribution of biotic assemblages and microfacies at the platform scale. Results demonstrate that the Lime Peak platform was surrounded by a basin with an aphotic sea bottom. The carbonate complex developed in warm waters characterized by high carbonate saturation. The area was also defined by moderate to high nutrient levels: this influenced the type of carbonate factory by favouring microbialites and sponges over corals. During its growth, Lime Peak was influenced by tectono-eustatism, which controlled the accommodation space at the platform top, primarily impacting the internal platform environments and the stability of the slope. Gaining better knowledge of the spatial distribution and dynamics of Upper Triassic organisms and sedimentary facies of Panthalassa in relation to tectono-eustatism lays the first foundations for reconstructing more robust platform models and understanding the evolution of other, more dismantled Upper Triassic Panthalassan carbonate systems through time. Full article

Sampling hides from harvested animals is commonly used for passive monitoring of ectoparasites on wildlife hosts, but often relies heavily on community engagement to obtain spatially and temporally consistent samples. Surveillance of winter ticks (Dermacentor albipictus) on moose (Alces alces) and caribou (Rangifer tarandus caribou) hosts in Yukon, Canada, has relied in part on voluntary submission of hides by hunters since 2011, but few samples were submitted. To enhance sampling efforts on underrepresented moose and caribou hosts, we implemented a three-year citizen science program, the Yukon Winter Tick Monitoring Project (YWTMP), to better engage with hunters in hide sample collection. A combination of in-person and social media outreach, incentivized engagement, and standardized hide sampling kits increased voluntary submissions of moose and caribou hides almost 100-fold since surveillance began. Citizen science samples expanded the northernmost geographic extent of existing sampling efforts for moose by 480 km and for caribou by 650 km to reach 67.5° N latitude. Samples also resulted in new detections of winter ticks on moose hides that are spatially separate to those submitted for other cervids in Yukon. Findings from the YWTMP have provided an essential baseline to monitor future winter tick host–parasite dynamics in the region and highlighted priority areas for ongoing tick surveillance. Full article