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1.
Can Bull Med Hist ; 38(2): 285-319, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34403611

RESUMO

This article examines the history of diphtheria in the Yukon and the Mackenzie district of the Northwest Territories in the first half of the 20th century. This analysis follows the traces of this now largely forgotten disease and its treatment to illuminate the constraints - intrinsic and constructed - on the provision of health care commensurate with the expectations and needs of northern Indigenous peoples. While diphtheria was never the most serious infectious disease, nor a major cause of death compared with tuberculosis or influenza at this time, examining its history offers significant insight into the creation of medical and public health infrastructures in Canada's northern territories, and the ways in which those infrastructures served, and failed to serve, different northern populations.


Assuntos
Antitoxina Diftérica , Acesso aos Serviços de Saúde , Instalações de Saúde , Territórios do Noroeste , Yukon
2.
PLoS One ; 16(7): e0253895, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34197512

RESUMO

Assessing species status and making classification decisions under the Endangered Species Act is a critical step towards effective species conservation. However, classification decisions are liable to two errors: i) failing to classify a species as threatened or endangered that should be classified (underprotection), or ii) classifying a species as threatened or endangered when it is not warranted (overprotection). Recent surveys indicate threatened spectacled eider populations are increasing in western Alaska, prompting the U.S. Fish and Wildlife Service to reconsider the federal listing status. There are multiple criteria set for assessing spectacled eider status, and here we focus on the abundance and decision analysis criteria. We estimated population metrics using state-space models for Alaskan breeding populations of spectacled eiders. We projected abundance over 50 years using posterior estimates of abundance and process variation to estimate the probability of quasi-extinction. The decision analysis maps the risk of quasi-extinction to the loss associated with making a misclassification error (i.e., underprotection) through a loss function. Our results indicate that the Yukon Kuskokwim Delta breeding population in western Alaska has met the recovery criteria but the Arctic Coastal Plain population in northern Alaska has not. The methods employed here provide an example of accounting for uncertainty and incorporating value judgements in such a way that the decision-makers may understand the risk of committing a misclassification error. Incorporating the abundance threshold and decision analysis in the reclassification criteria greatly increases the transparency and defensibility of the classification decision, a critical aspect for making effective decisions about species management and conservation.


Assuntos
Tomada de Decisões Gerenciais , Técnicas de Apoio para a Decisão , Patos , Espécies em Perigo de Extinção/legislação & jurisprudência , Alaska , Animais , Teorema de Bayes , Monitorização de Parâmetros Ecológicos/estatística & dados numéricos , Espécies em Perigo de Extinção/estatística & dados numéricos , Estados Unidos , Yukon
3.
Int J Circumpolar Health ; 80(1): 1948254, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34278981

RESUMO

Although rates of substance use are higher in the Canadian territories than the provinces, there is little research on cannabis use. This exploratory study describes cannabis use and related risk behaviours among alcohol consumers in Whitehorse (Yukon) and Yellowknife (Northwest Territories), with comparisons to data from the provinces. Prior to non-medical cannabis legalisation, respondents (n = 387) aged ≥19 were recruited from a study on alcohol labelling to complete an online cannabis survey. Logistic regression was used to compare territorial and provincial data, and correlates of cannabis use in the territories. Forty-seven percent of respondents were past 12-month cannabis consumers, and 15.5% were daily/almost daily consumers, significantly higher than in the provinces (p < 0.001 for both). Dried herb (85.7%) and edibles (58.2%) were most commonly used among consumers. Use of dried herb, edibles, solid concentrates and tinctures was significantly higher than in the provinces (all p ≤ 0.01). Twenty-four percent of respondents had ridden with a driver who had used cannabis, while 31.9% of cannabis consumers had driven within 2h of cannabis use, significantly higher than the provinces (both p < 0.001). Further research should examine the impact of legalisation on cannabis use in the territories, including rural communities.


Assuntos
Cannabis , Canadá/epidemiologia , Humanos , Territórios do Noroeste , Inquéritos e Questionários , Yukon
4.
BMC Public Health ; 21(1): 1247, 2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34187423

RESUMO

BACKGROUND: Automated Emergency Department syndromic surveillance systems (ED-SyS) are useful tools in routine surveillance activities and during mass gathering events to rapidly detect public health threats. To improve the existing surveillance infrastructure in a lower-resourced rural/remote setting and enhance monitoring during an upcoming mass gathering event, an automated low-cost and low-resources ED-SyS was developed and validated in Yukon, Canada. METHODS: Syndromes of interest were identified in consultation with the local public health authorities. For each syndrome, case definitions were developed using published resources and expert elicitation. Natural language processing algorithms were then written using Stata LP 15.1 (Texas, USA) to detect syndromic cases from three different fields (e.g., triage notes; chief complaint; discharge diagnosis), comprising of free-text and standardized codes. Validation was conducted using data from 19,082 visits between October 1, 2018 to April 30, 2019. The National Ambulatory Care Reporting System (NACRS) records were used as a reference for the inclusion of International Classification of Disease, 10th edition (ICD-10) diagnosis codes. The automatic identification of cases was then manually validated by two raters and results were used to calculate positive predicted values for each syndrome and identify improvements to the detection algorithms. RESULTS: A daily secure file transfer of Yukon's Meditech ED-Tracker system data and an aberration detection plan was set up. A total of six syndromes were originally identified for the syndromic surveillance system (e.g., Gastrointestinal, Influenza-like-Illness, Mumps, Neurological Infections, Rash, Respiratory), with an additional syndrome added to assist in detecting potential cases of COVID-19. The positive predictive value for the automated detection of each syndrome ranged from 48.8-89.5% to 62.5-94.1% after implementing improvements identified during validation. As expected, no records were flagged for COVID-19 from our validation dataset. CONCLUSIONS: The development and validation of automated ED-SyS in lower-resourced settings can be achieved without sophisticated platforms, intensive resources, time or costs. Validation is an important step for measuring the accuracy of syndromic surveillance, and ensuring it performs adequately in a local context. The use of three different fields and integration of both free-text and structured fields improved case detection.


Assuntos
COVID-19 , Vigilância de Evento Sentinela , Canadá , Serviço Hospitalar de Emergência , Humanos , Vigilância da População , Vigilância em Saúde Pública , SARS-CoV-2 , Texas , Yukon
5.
Ecology ; 102(9): e03456, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34165786

RESUMO

Food availability and temporal variation in predation risk are both important determinants of the magnitude of antipredator responses, but their effects have rarely been examined simultaneously, particularly in wild prey. Here, we determine how food availability and long-term predation risk affect antipredator responses to acute predation risk by monitoring the foraging response of free-ranging snowshoe hares (Lepus americanus) to an encounter with a Canada lynx (Lynx canadensis) in Yukon, Canada, over four winters (2015-2016 to 2018-2019). We examined how this response was influenced by natural variation in long-term predation risk (2-month mortality rate of hares) while providing some individuals with supplemental food. On average, snowshoe hares reduced foraging time up to 10 h after coming into close proximity (≤75 m) with lynx, and reduced foraging time an average of 15.28 ± 7.08 min per lynx encounter. Hares tended to respond more strongly when the distance to lynx was shorter. More importantly, the magnitude of hares' antipredator response to a lynx encounter was affected by the interaction between food-supplementation and long-term predation risk. Food-supplemented hares reduced foraging time more than control hares after a lynx encounter under low long-term risk, but decreased the magnitude of the response as long-term risk increased. In contrast, control hares increased the magnitude of their response as long-term risk increased. Our findings show that food availability and long-term predation risk interactively drive the magnitude of reactive antipredator response to acute predation risk. Determining the factors driving the magnitude of antipredator responses would contribute to a better understanding of the indirect effects of predators on prey populations.


Assuntos
Cadeia Alimentar , Comportamento Predatório , Animais , Yukon
6.
CMAJ Open ; 9(2): E585-E591, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34021017

RESUMO

BACKGROUND: We identified the need to modernize frostbite management in our northern centre and implemented a treatment protocol in 2015. Our aim was to describe the clinical course of patients presenting to the hospital since the implementation of the protocol. METHODS: This was a retrospective case series from Whitehorse General Hospital, Whitehorse, Yukon Territory, Canada. We reviewed the charts of patients who presented to the hospital with grade 2-4 frostbite and were treated as per our protocol between Feb. 9, 2015, and Feb. 8, 2020. Patients with grade 2-4 frostbite received iloprost; in addition, those with grade 4 frostbite received alteplase and heparin. We determined the number of digits affected and salvaged, and the time from presentation to the emergency department to treatment initiation. We also examined patients' demographic characteristics, predisposing events, frostbite severity and adverse drug reactions. RESULTS: In 22 patients treated for grade 2-4 frostbite, 142 digits were affected: 59 with grade 2 frostbite, 25 with grade 3 frostbite and 58 with grade 4 frostbite; of the 142, 113 (79.6%) were salvaged. All 29 digits amputated had grade 4 frostbite. The mean time from presentation to iloprost initiation was reduced from 32.9 hours in 2015 to 3.0 hours in 2020. Sports (10 cases [45%]) and alcohol use (6 [27%]) were the most common precipitating events, with alcohol use tending to result in more severe injury (grade 4 in 5 of 6 cases). Adverse reactions with iloprost (e.g., headache) were common but mild. Adverse reactions with alteplase (e.g., bleeding) were less common but of greater clinical significance. INTERPRETATION: Over the study period, our protocol contributed to improvement in frostbite care at our institution, resulting in a digit salvage rate comparable to other published results. Our 5-year experience shows that advanced medical care of frostbite can be achieved, even at a rural centre.


Assuntos
Amputação , Dedos , Congelamento das Extremidades , Heparina , Iloprosta , Ativador de Plasminogênio Tecidual , Adulto , Consumo de Bebidas Alcoólicas/epidemiologia , Amputação/métodos , Amputação/estatística & dados numéricos , Serviços Médicos de Emergência/métodos , Feminino , Fibrinolíticos/administração & dosagem , Fibrinolíticos/efeitos adversos , Dedos/patologia , Dedos/cirurgia , Congelamento das Extremidades/diagnóstico , Congelamento das Extremidades/epidemiologia , Congelamento das Extremidades/cirurgia , Congelamento das Extremidades/terapia , Heparina/administração & dosagem , Heparina/efeitos adversos , Humanos , Iloprosta/administração & dosagem , Iloprosta/efeitos adversos , Masculino , Avaliação de Processos e Resultados em Cuidados de Saúde , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Esportes/estatística & dados numéricos , Tempo para o Tratamento/normas , Ativador de Plasminogênio Tecidual/administração & dosagem , Ativador de Plasminogênio Tecidual/efeitos adversos , Vasodilatadores/administração & dosagem , Vasodilatadores/efeitos adversos , Yukon/epidemiologia
7.
Dis Aquat Organ ; 144: 123-131, 2021 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-33955850

RESUMO

Preliminary evidence suggests that Chinook salmon Oncorhynchus tshawytscha from the Yukon River may be more susceptible to Ichthyophonus sp. infections than Chinook from stocks further south. To investigate this hypothesis in a controlled environment, we experimentally challenged juvenile Chinook from the Yukon River and from the Salish Sea with Ichthyophonus sp. and evaluated mortality, infection prevalence and infection load over time. We found that juvenile Chinook salmon from a Yukon River stock were more susceptible to ichthyophoniasis than were those from a Salish Sea stock. After feeding with tissues from infected Pacific herring Clupea pallasii, Chinook salmon from both stocks became infected. The infection was persistent and progressive in Yukon River stock fish, where infections sometimes progressed to mortality, and histological examinations revealed parasite dissemination and proliferation throughout the host tissues. In Salish Sea-origin fish, however, infections were largely transient; host mortalities were rare, and parasite stages were largely cleared from most tissues after 3-4 wk. Susceptibility differences were evidenced by greater cumulative mortality, infection prevalence, parasite density, proportion of fish demonstrating a cellular response, and intensity of the cellular response among fish from the Yukon River stock. These observed differences between Chinook salmon stocks were consistent when parasite exposures occurred in both freshwater and seawater. These results support the hypothesis that a longer-standing host-pathogen relationship, resulting in decreased disease susceptibility, exists among Salish Sea Chinook salmon than among Yukon River conspecifics.


Assuntos
Doenças dos Peixes , Mesomycetozoea , Animais , Doenças dos Peixes/epidemiologia , Rios , Salmão , Yukon
8.
Forensic Sci Int Genet ; 53: 102536, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34058532

RESUMO

The moose is a highly prized game species in North America and is often the target of illegal harvesting. Forensic DNA analysis can be used to assist in investigations into wildlife crime by providing the link between the illegal incidents and suspects. In this study, we present the development and validation of a short-tandem repeat (STR) based forensic DNA test for the individualization of moose in Alberta and Yukon, Canada. We show that the markers used in the test are appropriate for forensic use and are sufficiently specific to moose. We also demonstrate the limit of detection and quantitation of the moose STR test on the ABI 3500 genetic analyzer. Lastly, we describe the population genetic structure of moose present in our forensic population database and make recommendations regarding the calculation of appropriately conservative forensic statistics.


Assuntos
Impressões Digitais de DNA , Cervos/genética , Repetições de Microssatélites , Alberta , Amelogenina/genética , Animais , Eletroforese Capilar , Genótipo , Reação em Cadeia da Polimerase , Yukon
9.
J Wildl Dis ; 57(2): 429-433, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33822166

RESUMO

Trichinella spp. nematodes are commonly found in bear species (Ursidae) and can pose severe health risks to humans when infective first-stage larvae are ingested in meat. Samples of tongue or masseter muscle from 22 male and 11 female American black bears (Ursus americanus; mean age 6.5 yr, range 1-16 yr) and 22 male, eight female, and one unknown sex grizzly bears (Ursus arctos; mean age 8.8 yr, range 2-28 yr), from Yukon, Canada, were tested to determine prevalence and intensity of Trichinella spp. infection. For black bears, prevalence was 20% and mean intensity was 401 larvae per gram of tissue (LPG), whereas for grizzly bears, prevalence was 71%, and mean infection intensity was 35 LPG. Isolates from all positive samples were identified as genotype Trichinella-T6 by multiplex PCR. For black bears, prevalence is the highest reported in Canada and infection intensity the highest recorded in North America. One black bear had a larval burden of 1,173 LPG, the second highest recorded in any host species. The prevalence in grizzly bears was the highest reported in Canada for this host. In total, 90% (27 of 30) of infected bears had infection burdens above the human food safety threshold of ≥1 LPG, reinforcing the importance of communicating the health risks to people consuming bear meat.


Assuntos
Trichinella/isolamento & purificação , Triquinelose/veterinária , Ursidae/parasitologia , Animais , Feminino , Masculino , Triquinelose/epidemiologia , Triquinelose/parasitologia , Yukon/epidemiologia
10.
Oecologia ; 195(4): 949-957, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33743069

RESUMO

Determining the factors driving cyclic dynamics in species has been a primary focus of ecology. For snowshoe hares (Lepus americanus), explanations of their 10-year population cycles most commonly feature direct predation during the peak and decline, in combination with their curtailment in reproduction. Hares are thought to stop producing third and fourth litters during the cyclic decline and do not recover reproductive output for several years. The demographic effects of these reproductive changes depend on the consistency of this pattern across cycles, and the relative contribution to population change of late-litter versus early litter juveniles. We used monitoring data on snowshoe hares in Yukon, Canada, to examine the contribution of late-litter juveniles to the demography of their cycles, by assigning litter group for individuals caught in autumn based on body size and capture date. We found that fourth-litter juveniles occur consistently during the increase phase of each cycle, but are rare and have low over-winter survival (0.05) suggesting that population increase is unlikely to be caused by their occurrence. The proportion of third-litter juveniles captured in the autumn remains relatively constant across cycle phases, while over-winter survival rates varies particularly for earlier-litter juveniles (0.14-0.39). Juvenile survival from all litters is higher during the population increase and peak, relative to the low and decline. Overall, these results suggest that the transition from low phase to population growth may stem in large part from changes in juvenile survival as opposed to increased reproductive output through the presence of a 4th litter.


Assuntos
Lebres , Animais , Canadá , Humanos , Dinâmica Populacional , Comportamento Predatório , Yukon
11.
Parasit Vectors ; 14(1): 146, 2021 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-33685525

RESUMO

BACKGROUND: Species of Trichinella are globally important foodborne parasites infecting a number of domestic and wild vertebrates, including humans. Free-ranging carnivores can act as sentinel species for detection of Trichinella spp. Knowledge of the epidemiology of these parasites may help prevent Trichinella spp. infections in northern Canadian animals and people. Previous research on Trichinella spp. in wildlife from Yukon did not identify risk factors associated with infection, or the diversity and identity of species of Trichinella in regional circulation, based on geographically extensive sampling with large sample sizes. METHODS: In a cross-sectional study, we determined the prevalence, infection intensity, risk factors, and species or genotypes of Trichinella in wolverine (Gulo gulo) in two regions of Yukon, Canada, from 2013-2017. A double separatory funnel digestion method followed by mutiplex PCR and PCR-RFLP were used to recover and identify species of Trichinella, respectively. RESULTS: We found larvae of Trichinella in the tongues of 78% (95% CI 73-82) of 338 wolverine sampled. The odds of adult (≥ 2 years) and yearling (1 year) wolverine being Trichinella spp.-positive were four and two times higher, respectively, compared to juveniles (<1 year). The odds of Trichinella spp. presence were three times higher in wolverine from southeast than northwest Yukon. The mean intensity of infection was 22.6 ± 39 (SD, range 0.1-295) larvae per gram. Trichinella T6 was the predominant genotype (76%), followed by T. nativa (8%); mixed infections with Trichinella T6 and T. nativa (12%) were observed. In addition, T. spiralis was detected in one wolverine. Out of 22 isolates initially identified as T. nativa in multiplex PCR, 14 were analyzed by PCR-RFLP to distinguish them from T. chanchalensis, a recently discovered cryptic species, which cannot be distinguished from the T. nativa on multiplex PCR. Ten isolates were identified either as T. chanchalensis alone (n = 7), or mixed infection with T. chanchalensis and T. nativa (n = 2) or T. chanchalensis and Trichinella T6 (n = 1)]. CONCLUSIONS: Wolverine hosted high prevalence, high larval intensity, and multiple species of Trichinella, likely due to their scavenging habits, apex position in the food chain, and wide home range. Wolverine (especially adult males) should be considered as a sentinel species for surveys for Trichinella spp. across their distributional range.


Assuntos
Variação Genética , Mustelidae/parasitologia , Trichinella/genética , Triquinelose/epidemiologia , Triquinelose/veterinária , Fatores Etários , Animais , Animais Selvagens/parasitologia , Canadá/epidemiologia , Estudos Transversais , Feminino , Genótipo , Masculino , Prevalência , Fatores de Risco , Língua/parasitologia , Trichinella/classificação , Yukon/epidemiologia
12.
Eur J Sport Sci ; 21(1): 100-106, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32089095

RESUMO

There is scarcity of research examining the physiological and psychological effects of ultra-endurance racing on athletes in extreme conditions. The purpose of the current study was to identify common injury patterns and illness, profile mood states and sleep patterns and finally examine the relationships between mental toughness, sleep, mood and injury rates during a 120 mile, three-day Arctic ultra-marathon. Twelve participants (3 females, 9 males) with a mean age of 42 ± 5.35 yrs participated in the study. Mental toughness was measured using the MT18 questionnaire. Injuries were clinically assessed and recorded each day. Temperatures ranged from -20 to -6 degrees Celsius throughout the race. Sleep quantity and mood state were recorded using the BRUMS questionnaire. 10 out of the 12 participants experienced injuries; almost half of the participants had injuries that carried over a number of days. Mean sleep duration over the three days was 4.07 h, with an average of 0.78 injuries per day. Significant changes in mood were recorded across the three days, specifically a reduction in vigour (p = .029) and increase in fatigue (p = .014). Neither sleep quantity nor mental toughness was correlated with injury rate. Interestingly, sleep quantity was not related to changes in mood, as previously shown in ultra-marathons. Mental toughness had a moderate negative correlation (p < 0.01) with depression (-.623), reduced anger (-.616), confusion (-.558), increased vigour (.497) and tension (-.420) during the race. Success in this type of event involves significant psychological and physiological preparation to minimize the effects of sleep deprivation and avoidance of injuries.


Assuntos
Afeto , Temperatura Baixa , Corrida de Maratona/lesões , Corrida de Maratona/psicologia , Resiliência Psicológica , Sono/fisiologia , Adulto , Ira , Regiões Árticas , Traumatismos em Atletas/epidemiologia , Traumatismos em Atletas/prevenção & controle , Confusão/etiologia , Depressão/etiologia , Metabolismo Energético/fisiologia , Fadiga/fisiopatologia , Fadiga/psicologia , Feminino , Humanos , Masculino , Corrida de Maratona/fisiologia , Territórios do Noroeste , Estudos Prospectivos , Inquéritos e Questionários , Fatores de Tempo , Yukon
13.
Sci Total Environ ; 764: 142906, 2021 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-33115600

RESUMO

High latitude, boreal watersheds are nitrogen (N)-limited ecosystems that export large amounts of organic carbon (C). Key controls on C cycling in these environments are the biogeochemical processes affecting the N cycle. A study was conducted in Nome Creek, an upland tributary of the Yukon River, and two headwater tributaries to Nome Creek, to examine the relation between seasonal and transport-associated changes in C and N pools and N-cycling processes using laboratory bioassays of water and sediment samples and in-stream tracer tests. Dissolved organic nitrogen (DON) exceeded dissolved inorganic nitrogen (DIN) in Nome Creek except late in the summer season, with little variation in organic C:N ratios with time or transport distance. DIN was dominant in the headwater tributaries. Rates of organic N mineralization and denitrification in laboratory incubations were positively correlated with sediment organic C content, while nitrification rates differed greatly between two headwater tributaries with similar drainages. Additions of DIN or urea did not stimulate microbial activity. In-stream tracer tests with nitrate and urea indicated that uptake rates were slow relative to transport rates; simulated rates of uptake in stream storage zones were higher than rates assessed in the laboratory bioassays. In general, N-cycle processes were more active and had a greater overall impact in the headwater tributaries and were minimized in Nome Creek, the larger, higher velocity, transport-dominated stream. Given expectations of permafrost thaw and increased hydrologic cycling that will flush more inorganic N from headwater streams, our results suggest higher N loads from these systems in the future.


Assuntos
Nitrogênio , Rios , Alaska , Ecossistema , Nitrogênio/análise , Yukon
14.
Environ Pollut ; 268(Pt B): 115777, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33120147

RESUMO

Use of elemental mercury (Hg0) to enhance placer gold recovery is an effective method dating back centuries, but is associated with significant atmospheric Hg0 losses. This method was widely used in the Canadian Klondike region during most of the 20th century when the mining industry experienced rapid growth. While the health risks associated with Hg0 pollution are now well understood, few studies have assessed the environmental legacy of Hg0 use in the Klondike. We used an annually resolved Picea glauca tree-ring Hg record (1864-2015) to reconstruct and evaluate changes in local atmospheric Hg0 concentrations associated with gold production at the Bear Creek mining camp. Major temporal trends in the record are consistent with the scale of Bear Creek operations and are distinct from background trends at an unimpacted control site. Tree-ring Hg concentration increased most rapidly from 1923 to 1930, a period when several major mining operations were consolidated at Bear Creek. The highest Hg concentrations, ∼2.5× greater than pre-mining era, occurred in the 1930s, coinciding with maximum gold production at this site. Post-World War II economic factors adversely affected the industry, causing declining tree-ring Hg concentrations from 1939 to 1966. Closure of the Bear Creek camp in 1966 coincided with the strongest tree-ring Hg decline, although a return to background levels did not occur until the 1990s, likely due to re-emission of legacy Hg0 from contaminated soils. Finally, a robust increase was observed over the last decade, similar to other tree-ring Hg records in N.W. Canada, which is linked to rising Hg0 emissions in Asia. The Bear Creek tree-ring Hg record provides a unique opportunity to study the impact of Klondike gold mining on the local environment at annual resolution and demonstrates great potential to use Picea tree rings to study past changes in atmospheric Hg0 from local and global emissions. MAIN FINDINGS: A 151-year long, annually resolved tree-ring Hg record was developed at a historic Klondike gold-mining site to investigate the influence of mining-related Hg0 emissions on the local atmosphere and environment. Compared to a control site, the tree-ring Hg record documents highly elevated atmospheric Hg0 concentrations during the period mining activities were ongoing at this site.


Assuntos
Mercúrio , Ursidae , Animais , Ásia , Canadá , Monitoramento Ambiental , Ouro , Mercúrio/análise , Mineração , Yukon
15.
Drug Alcohol Rev ; 40(2): 247-257, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33078447

RESUMO

INTRODUCTION AND AIMS: This paper examines the impact of an alcohol labelling intervention on recall of and support for standard drink (SD) labels, estimating the number of SDs in alcohol containers, and intended and unintended use of SD labels. DESIGN AND METHODS: A quasi-experimental study was conducted in Canada where labels with a cancer warning, national drinking guidelines and SD information were applied to alcohol containers in the single liquor store in the intervention site, while usual labelling continued in the two liquor stores in the comparison site. Three waves of surveys were conducted in both sites before and at two time-points after the intervention with 2049 cohort participants. Generalised estimating equations were applied to estimate changes in all outcomes. RESULTS: Participants in the intervention relative to the comparison site had greater odds of recalling [adjusted odds ratio (AOR) 5.69, 95% confidence interval (CI) 3.02, 10.71] and supporting SD labels (AOR 1.49, 95% CI 1.04, 2.12) and lower odds of reporting using SD labels to purchase high strength, low-cost alcohol (AOR 0.65, 95% CI 0.45, 0.93). Exposure to the labels had negligible effects on accurately estimating the number of SDs (AOR 1.06, 95% CI 0.59, 1.93) and using SD labels to drink within guidelines (AOR 1.04, 95% CI 0.75, 1.46). DISCUSSION AND CONCLUSIONS: Evidence-informed labels increased support for and decreased unintended use of SD labels. Such labels can improve accuracy in estimating the number of SDs in alcohol containers and adherence to drinking guidelines.


Assuntos
Consumo de Bebidas Alcoólicas , Bebidas Alcoólicas , Rotulagem de Produtos , Consumo de Bebidas Alcoólicas/epidemiologia , Consumo de Bebidas Alcoólicas/prevenção & controle , Humanos , Yukon/epidemiologia
16.
Sci Total Environ ; 760: 143339, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33183800

RESUMO

Several large-scale human biomonitoring projects have been conducted in Canada, including the Canadian Health Measures Survey (CHMS) and the First Nations Biomonitoring Initiative (FNBI). However, neither of these studies included participants living in the Yukon. To address this data gap, a human biomonitoring project was implemented in Old Crow, a fly-in Gwich'in community in the northern Yukon. The results of this project provide baseline levels of contaminant and nutrient biomarkers from Old Crow in 2019. Samples of hair, blood, and/or urine were collected from approximately 44% of community residents (77 of 175 adults). These samples were analyzed for contaminants (including heavy metals and persistent organic pollutants (POPs)), and nutrients (including trace elements and omega-3 fatty acids). Levels of these analytes were compared to health-based guidance values, when available, and results from other human biomonitoring projects in Canada. Levels of lead (GM 0.64 µg/g creatinine in urine/24 µg/L blood), cadmium (GM 0.32 µg/g creatinine in urine/0.85 µg/L blood), and mercury (GM < LOD in urine/0.76 µg/L blood/0.31 µg/g hair) were below select health-based guidance values for more than 95% of participants. However, compared to the general Canadian population, elevated levels of some contaminants, including lead (approximately 2× higher), cobalt (approximately 1.5× higher), manganese (approximately 1.3× higher), and hexachlorobenzene (approximately 1.5× higher) were observed. In contrast, levels of other POPs, including insecticides such as dichlorodiphenyltrichloroethane (DDT), its metabolite, dichlorodiphenyldichloroethylene (DDE), and polychlorinated biphenyls (PCBs) were similar to, or lower than, those reported in the general Canadian population. This study can be used along with future biomonitoring programs to evaluate the effectiveness of international initiatives designed to reduce the contaminant burden in the Arctic, including the Stockholm Convention and the Minamata Convention. Regionally, this project complements environmental monitoring being conducted in the region, informing local and regional traditional food consumption advisories.


Assuntos
Corvos , Poluentes Ambientais , Adulto , Animais , Regiões Árticas , Monitoramento Biológico , Biomarcadores , Canadá , Monitoramento Ambiental , Poluentes Ambientais/análise , Humanos , Yukon
17.
Parasit Vectors ; 13(1): 565, 2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33176864

RESUMO

BACKGROUND: The winter tick (Dermacentor albipictus) has garnered significant attention throughout North America for its impact on wildlife health, and especially for moose (Alces alces), where high tick burdens may result in host hair loss, anemia, and can prove fatal. The environmental transmission of D. albipictus larvae to a host is a critical event that has direct impact on infestation success, yet in-field observations of this life stage are lacking. In Yukon, Canada, D. albipictus had previously been found on hosts, but its larval life stage had not been detected in the field, despite previous sampling attempts. METHODS: We sampled for D. albipictus larvae using traditional flagging methods in Ibex Valley and Braeburn, Yukon. Sites were sampled repeatedly for D. albipictus larvae by flagging from late August to end of October in 2018 and late August to end of November 2019. RESULTS: Larvae of D. albipictus were collected throughout Ibex Valley, at approximate densities ranging from 0.04 to 4236 larvae/100 m2. Larvae were present primarily on grassy vegetation on south-facing slopes in the Ibex Valley region and in Braeburn. Highest average larval numbers suggest peak questing activity was towards the end of September and beginning of October, as elsewhere in North America. CONCLUSIONS: To the best of our knowledge, we report the first successful collection of the off-host, larval life stage of D. albipictus by flagging, north of 60° latitude in Yukon, Canada. These new observations provide critical information on the spatial distribution of the host-seeking life stage of D. albipictus and confirm that this species is completing its whole life cycle in southern Yukon. Understanding the environmental conditions where larvae spend their vulnerable period off-host in this northern location can inform both management strategies and projections of future range expansion which may occur with a changing climate.


Assuntos
Cervos/parasitologia , Dermacentor/fisiologia , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/veterinária , Animais , Canadá/epidemiologia , Cervos/classificação , Larva , Estações do Ano , Yukon
18.
CMAJ Open ; 8(4): E637-E642, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33077534

RESUMO

BACKGROUND: Genetic testing in families with hereditary cancer enables identification of people most likely to benefit from intensive screening and preventive measures; however, the uptake of testing in relatives (known as cascade carrier testing) for hereditary colorectal cancer syndromes has been shown to be low. Our objective was to report rates of familial testing for hereditary colorectal cancer syndromes in a publicly funded hereditary cancer clinic in Canada. METHODS: A cross-sectional retrospective database review was used to determine testing uptake between 1997 and 2016 for families served by the provincial Hereditary Cancer Program for British Columbia and Yukon. Analyses were conducted for genes associated with syndromes with an increased risk for colorectal cancer, including Lynch syndrome (MLH1, MSH2, MSH6, PMS2 and EPCAM) and familial adenomatous polyposis (APC), and for additional moderate- to high-penetrance genes (STK11, TP53, SMAD4, MUTYH, PTEN and CHEK2). Descriptive statistics were used and all analyses were 2-tailed. RESULTS: The study cohort included 245 index patients, with carrier testing performed in 382 relatives. The mean age at family member testing was 41.2 years, and most (61.0%) of the family members who underwent testing were women. The median time between disclosure of index cases and their family member's results was 8.3 months. Among eligible first-degree relatives, 32.6% (268/821) underwent testing in BC. Of 67 cancer diagnoses in family members, most (62.7%) occurred before genetic testing. INTERPRETATION: A substantial proportion of people at risk for hereditary colorectal cancer do not undergo genetic testing. This gap highlights the need to explore barriers to testing and to consider interventions to promote uptake; more aggressive efforts by hereditary cancer programs are needed to reach this highest risk population.


Assuntos
Polipose Adenomatosa do Colo/diagnóstico , Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Predisposição Genética para Doença , Testes Genéticos/estatística & dados numéricos , Polipose Adenomatosa do Colo/genética , Adulto , Idoso , Colúmbia Britânica , Neoplasias Colorretais Hereditárias sem Polipose/genética , Estudos Transversais , Bases de Dados Factuais , Família , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem , Yukon
19.
Sci Rep ; 10(1): 14295, 2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32868827

RESUMO

This study aims to act as a methodological guide for contamination monitoring, decontamination, and DNA extraction for peaty and silty permafrost samples with low biomass or difficult to extract DNA. We applied a biological tracer, either only in the field or both in the field and in the lab, via either spraying or painting. Spraying in the field followed by painting in the lab resulted in a uniform layer of the tracer on the core sections. A combination of bleaching, washing, and scraping resulted in complete removal of the tracer leaving sufficient material for DNA extraction, while other widely used decontamination methods did not remove all detectable tracer. In addition, of four widely used commercially available DNA extraction kits, only a modified ZymoBIOMICS DNA Microprep kit was able to acquire PCR amplifiable DNA. Permafrost chemical parameters, age, and soil texture did not have an effect on decontamination efficacy; however, the permafrost type did influence DNA extraction. Based on these findings, we developed recommendations for permafrost researchers to acquire contaminant-free DNA from permafrost with low biomass.


Assuntos
DNA/isolamento & purificação , Sedimentos Geológicos/química , Pergelissolo/química , Solo/química , Biomassa , DNA/genética , Descontaminação/métodos , Reação em Cadeia da Polimerase , Amostragem , Yukon
20.
J Anim Ecol ; 89(11): 2397-2414, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32929740

RESUMO

Long-term studies of wild animals provide the opportunity to investigate how phenotypic plasticity is used to cope with environmental fluctuations and how the relationships between phenotypes and fitness can be dependent upon the ecological context. Many previous studies have only investigated life-history plasticity in response to changes in temperature, yet wild animals often experience multiple environmental fluctuations simultaneously. This requires field experiments to decouple which ecological factor induces plasticity in fitness-relevant traits to better understand their population-level responses to those environmental fluctuations. For the past 32 years, we have conducted a long-term integrative study of individually marked North American red squirrels Tamiasciurus hudsonicus Erxleben in the Yukon, Canada. We have used multi-year field experiments to examine the physiological and life-history responses of individual red squirrels to fluctuations in food abundance and conspecific density. Our long-term observational study and field experiments show that squirrels can anticipate increases in food availability and density, thereby decoupling the usual pattern where animals respond to, rather than anticipate, an ecological change. As in many other study systems, ecological factors that can induce plasticity (such as food and density) covary. However, our field experiments that manipulate food availability and social cues of density (frequency of territorial vocalizations) indicate that increases in social (acoustic) cues of density in the absence of additional food can induce similar life-history plasticity, as does experimental food supplementation. Changes in the levels of metabolic hormones (glucocorticoids) in response to variation in food and density are one mechanism that seems to induce this adaptive life-history plasticity. Although we have not yet investigated the energetic response of squirrels to elevated density or its association with life-history plasticity, energetics research in red squirrels has overturned several standard pillars of knowledge in physiological ecology. We show how a tractable model species combined with integrative studies can reveal how animals cope with resource fluctuations through life-history plasticity.


Assuntos
Animais Selvagens , Cauda , Animais , Canadá , Sciuridae , Estados Unidos , Yukon
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