Long term safety and efficacy of the Yukon Choice Flex sirolimus-eluting coronary stent-a real-world data from India.

In-stent restenosis and stent thrombosis are the major concerns while choosing a coronary stent. This single-centre, retrospective study evaluated the one and three-year clinical outcomes following implantation of Yukon Choice Flex (YCF) sirolimus-eluting stent. A total of 168 consecutive patients with 217 lesions underwent stenting with YCF stent. The presentation was with acute coronary syndrome in 158 (94%) patients. At 3 years, 9 (5.3%) patients died due to cardiac cause. Myocardial infarction, and definite stent thrombosis occurred in 10 (6%) and 4 (2.4%) patients respectively. Redo stenting and coronary artery bypass surgery was performed in 3 (1.8%) and 1 (0.6%) patient respectively. The use of YCF sirolimus eluting stent was associated with a favourable safety and efficacy profile at one and three-years of follow-up in a high-risk population.

Use as directed: do standard drink labels on alcohol containers help consumers drink (ir)responsibly? Real-world evidence from a quasi-experimental study in Yukon, Canada.

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.

Genetic testing in families with hereditary colorectal cancer in British Columbia and Yukon: a retrospective cross-sectional analysis.

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.

The Effects of Alcohol Warning Labels on Population Alcohol Consumption: An Interrupted Time Series Analysis of Alcohol Sales in Yukon, Canada.

OBJECTIVE: There is limited evidence that alcohol warning labels (AWLs) affect population alcohol consumption. New evidence-informed AWLs were introduced in the sole government-run liquor store in Whitehorse, Yukon, that included a cancer warning (Ca), low-risk drinking guidelines (LRDGs) and standard drink (SD) messages. These temporarily replaced previous pregnancy warning labels. We test if the intervention was associated with reduced alcohol consumption. METHOD: An interrupted time series study was designed to evaluate the effects of the AWLs on consumption for 28 months before and 14 months after starting the intervention. Neighboring regions of Yukon and Northwest Territories served as control sites. About 300,000 labels were applied to 98% of alcohol containers sold in Whitehorse during the intervention. Multilevel regression analyses of per capita alcohol sales data for people age 15 years and older were performed to examine consumption levels in the intervention and control sites before, during, and after the AWLs were introduced. Models were adjusted for demographic and economic characteristics over time and region. RESULTS: Total per capita retail alcohol sales in Whitehorse decreased by 6.31% (t test p < .001) during the intervention. Per capita sales of labeled products decreased by 6.59% (t test p < .001), whereas sales of unlabeled products increased by 6.91% (t test p < .05). There was a still larger reduction occurring after the intervention when pregnancy warning labels were reintroduced (-9.97% and -10.29%, t test p < .001). CONCLUSIONS: Applying new AWLs was associated with reduced population alcohol consumption. The results are consistent with an accumulating impact of the addition of varying and highly visible labels with impactful messages.

Baseline Assessment of Alcohol-Related Knowledge of and Support for Alcohol Warning Labels Among Alcohol Consumers in Northern Canada and Associations With Key Sociodemographic Characteristics.

OBJECTIVE: Evidence-informed alcohol warning labels (AWLs) are a promising, well-targeted strategy to increase consumer awareness of health risks. We assessed consumers' baseline knowledge of alcohol-related cancer risk, standard drinks, and low-risk drinking guidelines as well as levels of support for AWLs. We further assessed associations with sociodemographic factors. METHOD: Forming part of a larger study testing new evidence-informed AWLs in a northern Canadian territory compared with a neighboring territory, baseline surveys were completed among liquor store patrons systematically selected in both sites. Chi-square and multivariable logistic regression analyses were performed to assess outcomes. RESULTS: In total, 836 liquor store patrons (47.8% female) completed baseline surveys across both sites. Overall, there was low knowledge of alcohol-related cancer risk (24.5%), limited ability to calculate a standard drink (29.5%), and low knowledge of daily (49.5%) and weekly (48.2%) low-risk drinking guideline limits. There was moderate support for AWLs with a health warning (55.9%) and standard drink information (51.4%), and lower support for low-risk drinking guideline labels (38.7%). No sociodemographic characteristics were associated with cancer knowledge. Identifying as female and having adequate health literacy were associated with support for all three AWLs; high alcohol use was associated with not supporting standard drink (adjusted odds ratio = 0.60, 95% CI [0.40, 0.88]) and low-risk drinking guideline (adjusted odds ratio = 0.57, 95% CI [0.38, 0.87]) labels. CONCLUSIONS: Few consumers in this study had key alcohol-related health knowledge; however, there was moderate support for AWLs as a tool to raise awareness. Implementation of information-based interventions such as evidence-informed AWLs with health messages including alcohol-related cancer risk, standard drink information, and national drinking guidelines is warranted.

Testing Alcohol Labels as a Tool to Communicate Cancer Risk to Drinkers: A Real-World Quasi-Experimental Study.

OBJECTIVE: This study tested the initial and continued effects of cancer warning labels on drinkers' recall and knowledge that alcohol can cause cancer. METHOD: A quasi-experiment was conducted to examine changes in the intervention versus comparison site for three outcomes: unprompted and prompted recall of the cancer warning, and knowledge that alcohol can cause cancer. The intervention site applied cancer warning labels to alcohol containers in its liquor store for 1 month, and the two liquor stores in the comparison site did not apply cancer labels. In total, 2,049 unique cohort participants (1,056 male) were recruited at liquor stores in the intervention and comparison sites to participate in surveys 4 months before labels were applied and 2 and 6 months after the cancer label was halted because of alcohol industry interference. Generalized estimating equations tested differences in outcomes between sites over time adjusting for socio-demographics and other covariates. RESULTS: Two months after the cancer label, unprompted (+24.2% vs. +0.6%; adjusted odds ratio [AOR] = 32.7, 95% CI [5.4, 197.7]) and prompted (+35.7% vs. +4.1%; AOR = 6.2, 95% CI [3.6, 10.9]) recall increased to a greater extent in the intervention versus comparison site. There was a 10% greater increase in knowledge (+12.1% vs. +11.6%; AOR = 1.1, 95% CI [0.7, 1.5]) 2 months after the cancer label in the intervention versus comparison site. Similar results were found 6 months after the cancer label for all three outcomes. CONCLUSIONS: In a real-world setting, cancer warning labels get noticed and increase knowledge that alcohol can cause cancer. Additional cancer label intervention studies are required that are not compromised by industry interference.

Examining the Impact of Alcohol Labels on Awareness and Knowledge of National Drinking Guidelines: A Real-World Study in Yukon, Canada.

OBJECTIVE: Alcohol labels are one strategy for communicating health information to consumers. This study tested the extent to which consumers recalled alcohol labels with national drinking guidelines and examined the impact of labels on awareness and knowledge of the guidelines. METHOD: A quasi-experimental study was conducted in two jurisdictions in northern Canada examining the impact of labels on the following outcomes: unprompted and prompted recall of the drinking guideline label message, awareness of the drinking guidelines, and knowledge of the daily and weekly recommended drink limits. The intervention site applied labels with national drinking guidelines, a cancer warning, and standard drink information to alcohol containers in its liquor store, whereas the comparison site did not apply these labels. In total, 2,049 cohort participants in both sites were recruited to complete surveys before and at two time points after the intervention. Changes in outcomes were examined using generalized estimating equations. RESULTS: After the intervention, unprompted and prompted recall of the drinking guideline label message increased more in the intervention versus comparison site (adjusted odds ratio [AOR] = 10.8, 95% CI [0.9, 127.6]; AOR = 7.0, 95% CI [3.3, 14.9], respectively). Awareness of the drinking guidelines increased 2.9 times more in the intervention versus comparison site (AOR = 2.9, 95% CI [2.0, 4.3]). In addition, knowledge of the daily and weekly drink limits increased 1.5 and 1.4 times more in the intervention versus comparison site, respectively (daily: AOR = 1.5, 95% CI [1.0, 2.1]; weekly: AOR = 1.4, 95% CI [1.0, 2.0]). CONCLUSIONS: Enhanced alcohol labels get noticed and may be an effective population-level strategy for increasing awareness and knowledge of national drinking guidelines.

Cancer Warning Labels on Alcohol Containers: A Consumer's Right to Know, a Government's Responsibility to Inform, and an Industry's Power to Thwart.

OBJECTIVE: Although the World Health Organization (WHO) declared alcohol a Class 1 carcinogen 30 years ago, few governments have communicated this fact to the public. We illustrate how alcohol industry groups seek to keep their customers in the dark about alcohol-related cancer risks. In Canada, a federally funded scientific study examining the introduction of cancer warning labels on containers was shut down following industry interference. We show that the industry complaints about the study had no legal merit. Of 47 WHO member countries with alcohol warning labels, only South Korea requires cancer warnings on alcohol containers. However, industry complaints, supported by sympathetic governments, helped weaken the warning labels' implementation. Ireland has legislated for cancer warnings but faces continuing legal opposition expressed through regional and global bodies. Cancer societies and the public health community have failed to counter industry pressures to minimize consumer awareness of alcohol's cancer risks. Placing cancer warnings on alcohol containers could make a pivotal difference in motivating both drinkers to consume less and regulators to introduce more effective policies to reduce the serious harms of alcohol consumption.

Effects of strengthening alcohol labels on attention, message processing, and perceived effectiveness: A quasi-experimental study in Yukon, Canada.

Alcohol labels are one strategy for raising consumer awareness about the negative consequences of alcohol, but evidence to inform labels is limited. This quasi-experimental study sought to test the real-world impact of strengthening health messages on alcohol container labels on consumer attention, message processing (reading, thinking, and talking with others about labels), and self-reported drinking. Alcohol labels with a cancer warning, national drinking guidelines, and standard drink information were implemented in the intervention site, and usual labelling practices continued in the comparison site. Changes in key indicators of label effectiveness were assessed among a cohort of adult drinkers in both the intervention and comparison sites using three waves of surveys conducted before and at two time-points after the alcohol label intervention. Generalized Estimating Equations with difference-in-difference terms were used to examine the impact of the label intervention on changes in outcomes. Strengthening health messages on alcohol container labels significantly increased consumer attention to [Adjusted Odds Ratio (AOR)=17.2, 95%CI:8.2,36.2] and processing of labels (e.g., reading labels: AOR=2.6, 95%CI:1.8,3.7), and consumer reports of drinking less due to the labels (AOR=3.7, 95%CI: 2.0,7.0). Strengthening health messages on alcohol containers can achieve their goal of attracting attention, deepening engagement, and enhancing motivation to reduce alcohol use. Strengthening alcohol labelling policies should be a priority for alcohol control globally.

Phenological shifts in North American red squirrels: disentangling the roles of phenotypic plasticity and microevolution.

Phenological shifts are the most widely reported ecological responses to climate change, but the requirements to distinguish their causes (i.e. phenotypic plasticity vs. microevolution) are rarely met. To do so, we analysed almost two decades of parturition data from a wild population of North American red squirrels (Tamiasciurus hudsonicus). Although an observed advance in parturition date during the first decade provided putative support for climate change-driven microevolution, a closer look revealed a more complex pattern. Parturition date was heritable [h2  = 0.14 (0.07-0.21 (HPD interval)] and under phenotypic selection [ß = -0.14 ± 0.06 (SE)] across the full study duration. However, the early advance reversed in the second decade. Further, selection did not act on the genetic contribution to variation in parturition date, and observed changes in predicted breeding values did not exceed those expected due to genetic drift. Instead, individuals responded plastically to environmental variation, and high food [white spruce (Picea glauca) seed] production in the first decade appears to have produced a plastic advance. In addition, there was little evidence of climate change affecting the advance, as there was neither a significant influence of spring temperature on parturition date or evidence of a change in spring temperatures across the study duration. Heritable traits not responding to selection in accordance with quantitative genetic predictions have long presented a puzzle to evolutionary ecologists. Our results on red squirrels provide empirical support for one potential solution: phenotypic selection arising from an environmental, as opposed to genetic, covariance between the phenotypic trait and annual fitness.

Cancer mortality in Yukon 1999-2013: elevated mortality rates and a unique cancer profile.

BACKGROUND: Although cancer is the leading cause of death in Canada, cancer in the North has been incompletely described. OBJECTIVE: To determine cancer mortality rates in the Yukon Territory, compare them with Canadian rates, and identify major causes of cancer mortality. DESIGN: The Yukon Vital Statistics Registry provided all cancer deaths for Yukon residents between 1999-2013. Age-standardised mortality rates (ASMRs) were calculated using direct standardisation and compared with Canadian rates. Standardised mortality ratios (SMRs) were calculated using indirect standardisation relative to age-specific rates from Canada, British Columbia (BC), and three sub-provincial BC administrative health regions : Interior Health (IH), Northern Health (NH) and Vancouver Coastal Health (VCH). Trends in smoothed ASMRs were examined with graphical methods. RESULTS: Yukon's all-cancer ASMRs were elevated compared with national and provincial rates for the entire period. Disparities were greatest compared with the urban VCH: prostate (SMRVCH=246.3, 95% CI 140.9-351.6), female lung (SMRVCH=221.2, 95% CI 154.3-288.1), female breast (SMRVCH=169.0 95% CI, 101.4-236.7), and total colorectal (SMRVCH=149.3, 95% CI 101.8-196.8) cancers were significantly elevated. Total stomach cancer mortality was significantly elevated compared with all comparators. CONCLUSIONS: Yukon cancer mortality rates were elevated compared with national, provincial, urban, and southern-rural jurisdictions. More research is required to elucidate these differences.

Population attributable risk associated with lung cancer induced by residential radon in Canada: Sensitivity to relative risk model and radon probability density function choices: In memory of Professor Jan M. Zielinski.

Indoor radon has been identified as the second leading cause of lung cancer after tobacco smoking. The Population Attributable Risk (PAR) estimates the proportion of lung cancer cases associated with indoor radon exposure. Different relative risk (RR) models have been used in the literature to calculate PAR. The aim of this study is to assess how sensitive PAR is to the relative risk model and radon probability distribution functions choices. METHODS: Using Canadian observed first floor radon data collected by Health Canada during the period October 2010 to March 2011, seven common PAR radon models used for North American miners and dwelling scenarios were applied. The death rates used for this study were from the period 2006-2009. Smoking data (Ever Smoking ES and Never Smoking NS) collected in 2009 was also used in this study. The original discrete radon data for Canada overall and for each of its provinces are estimated using log-normal and Gaussian kernel density estimator distributions. PAR was then calculated for Canada and its provinces using the empirical, log-normal, and Gaussian kernel estimates distributions. Finally, cancer death cases attributable to radon are reported for the constant relative risk model for the three distributions and the reduction in the cases when the action level 200Bq/m3 is applied. RESULTS: PAR for the Canadian data is sensitive to the model choice, and it varies with a range of 10% for ES and 32% for NS, respectively. There is little difference in results between miners' models and dwelling models. PAR values for ES females are greater than those for ES males, except in Saskatchewan, Northwest Territories, Nunavut, and Yukon. The male-female range overlaps. Gaussian kernel estimator produces PAR estimates similar to the commonly used log-normal distribution. CONCLUSION: Many lung cancer cases could be prevented in Canada by reducing indoor radon. PAR is sensitive to the choice of RR model. Miners' models can be used for residential radon. Empirical, log-normal, and Gaussian kernel density estimation with support [0,∞) can all be applied to radon data.

Healthcare in Canada's North: Are We Getting Value for Money?

OBJECTIVE: To determine if Canadians are getting value for money in providing health services to our northern residents. METHOD: Secondary analyses of data from Statistics Canada, the Canadian Institute of Health Information and territorial government agencies on health status, health expenditures and health system performance indicators. RESULTS: Per capita health expenditures in Canada's northern territories are double that of Canada as a whole and are among the highest in the world. The North lags behind the rest of the country in preventable mortality, hospitalization for ambulatory care sensitive conditions and other performance indicators. DISCUSSION: The higher health expenditure in the North is to be expected from its unique geography and demography. If the North is not performing as well as Canada, it is not due to lack of money, and policy makers should be concerned about whether healthcare can be as good as it could be.

Chlamydia screening practices among physicians and community nurses in Yukon, Canada.

BACKGROUND: Yukon, a territory in northern Canada, has one of the highest reported sexually transmitted chlamydia infection rates in the country. OBJECTIVE: We examined screening practices among physicians and community nurses to elucidate factors that may be contributing to the high rates. DESIGN: Cross-sectional survey. METHODS: A questionnaire was distributed to all physicians in Yukon and all community nurses in Yukon's communities. We surveyed sexual health assessment frequency, chlamydia testing frequency and barriers to screening. Comparison of physician testing practices was performed to another Canadian jurisdiction, which previously undertook a similar survey. Survey results were compared to the available laboratory data in Yukon. RESULTS: Eligible physicians and nurses, 79% and 77%, respectively, participated in the survey. Physicians tested 15 to 24-year-old females more frequently than 15 to 24-year-old males for chlamydia (p = 0.007). Physicians who asked sexual health assessment questions were more likely to test for chlamydia in both females (p < 0.001) and males (p = 0.032). More physicians screened females based on risk factors compared to males. General practice physicians in Yukon were more likely to test females for chlamydia than general practice physicians in Toronto, Canada (p < 0.001). Community nurses had different testing patterns than physicians, with a lower overall frequency of testing, equal frequency of testing males and females, and in applying risk factor-based screening to both males and females. Barriers to screening included testing causing patient discomfort, patients reluctant to discuss screening, health provider uncomfortable conducting sexually transmitted infection tests and sexual health assessments, among others. Laboratory data in Yukon appear to confirm provider screening patterns. CONCLUSIONS: This survey provides valuable information on health provider screening patterns. We have some evidence which suggests that chlamydia testing rates may be higher among patients seen by physicians in Yukon in comparison to another Canadian jurisdiction. However, more consistent application of optimal screening methods with support to "start the conversation" around sexual health may assist in overcoming barriers to screening and in addressing Yukon's high rate of chlamydia.

Challenges in conducting community-driven research created by differing ways of talking and thinking about science: a researcher's perspective.

Increasingly, health scientists are becoming aware that research collaborations that include community partnerships can be an effective way to broaden the scope and enhance the impact of research aimed at improving public health. Such collaborations extend the reach of academic scientists by integrating a variety of perspectives and thus strengthening the applicability of the research. Communication challenges can arise, however, when attempting to address specific research questions in these collaborations. In particular, inconsistencies can exist between scientists and community members in the use and interpretation of words and other language features, particularly when conducting research with a biomedical component. Additional challenges arise from differing perceptions of the investigative process. There may be divergent perceptions about how research questions should and can be answered, and in expectations about requirements of research institutions and research timelines. From these differences, misunderstandings can occur about how the results will ultimately impact the community. These communication issues are particularly challenging when scientists and community members are from different ethnic and linguistic backgrounds that may widen the gap between ways of talking and thinking about science, further complicating the interactions and exchanges that are essential for effective joint research efforts. Community-driven research that aims to describe the burden of disease associated with Helicobacter pylori infection is currently underway in northern Aboriginal communities located in the Yukon and Northwest Territories, Canada, with the goal of identifying effective public health strategies for reducing health risks from this infection. This research links community representatives, faculty from various disciplines at the University of Alberta, as well as territorial health care practitioners and officials. This highly collaborative work will be used to illustrate, from a researcher's perspective, some of the challenges of conducting public health research in teams comprising members with varying backgrounds. The consequences of these challenges will be outlined, and potential solutions will be offered.

Human papillomavirus infection and the association with abnormal Pap findings in Yukon, Canada.

OBJECTIVE: Certain types of the human papillomavirus (HPV) are highly associated with cervical cancer or dysplasia, but its prevalence is largely unknown in northern Canada where there is significant aboriginal representation and unique barriers to accessing care. This study determined the prevalence of HPV infection and its association with cervical cancer precursor lesions in Yukon, Canada. MATERIALS AND METHODS: This was a cross-sectional study of 1,542 women attending routine Pap smear screening in 14 communities in Yukon, from February 2009 to June 2010. Type-specific HPV infection was detected by an in-house Luminex assay. Cervical Pap cytology was evaluated by pathologists blinded to HPV test results. RESULTS: The overall HPV prevalence rate in Yukon women was higher than those reported in some Canadian provinces and other countries. Human papillomavirus infection prevalence rates were 24.5% for any type, 18.4% for high-risk types, 6.2% for HPV types 16 or 18, 6.7% for HPV α-7 species, and 10.6% for HPV α-9 species. Human papillomavirus infection was strongly associated with single marital status or having 2 or more sexual partners in the past year. Human papillomavirus infection (overall, high-risk types, HPV-16/18, α-7, or α-9 species) was strongly associated with Pap cytological abnormalities (adjusted odds ratios ranged from 8.4 to 44.2). CONCLUSIONS: As in other areas of northern Canada, HPV prevalence for high-risk types and α-7 species is high among women in the Yukon. Sexual behavioral factors strongly influence HPV prevalence rates. The findings may have implications for HPV vaccination and health promotion programs in northern regions.

Satellite microwave detection of boreal forest recovery from the extreme 2004 wildfires in Alaska and Canada.

The rate of vegetation recovery from boreal wildfire influences terrestrial carbon cycle processes and climate feedbacks by affecting the surface energy budget and land-atmosphere carbon exchange. Previous forest recovery assessments using satellite optical-infrared normalized difference vegetation index (NDVI) and tower CO(2) eddy covariance techniques indicate rapid vegetation recovery within 5-10 years, but these techniques are not directly sensitive to changes in vegetation biomass. Alternatively, the vegetation optical depth (VOD) parameter from satellite passive microwave remote sensing can detect changes in canopy biomass structure and may provide a useful metric of post-fire vegetation response to inform regional recovery assessments. We analyzed a multi-year (2003-2010) satellite VOD record from the NASA AMSR-E (Advanced Microwave Scanning Radiometer for EOS) sensor to estimate forest recovery trajectories for 14 large boreal fires from 2004 in Alaska and Canada. The VOD record indicated initial post-fire canopy biomass recovery within 3-7 years, lagging NDVI recovery by 1-5 years. The VOD lag was attributed to slower non-photosynthetic (woody) and photosynthetic (foliar) canopy biomass recovery, relative to the faster canopy greenness response indicated from the NDVI. The duration of VOD recovery to pre-burn conditions was also directly proportional (P < 0.01) to satellite (moderate resolution imaging spectroradiometer) estimated tree cover loss used as a metric of fire severity. Our results indicate that vegetation biomass recovery from boreal fire disturbance is generally slower than reported from previous assessments based solely on satellite optical-infrared remote sensing, while the VOD parameter enables more comprehensive assessments of boreal forest recovery.

Accumulated state of the Yukon River watershed: part I critical review of literature.

A consistent methodology for assessing the accumulating effects of natural and manmade change on riverine systems has not been developed for a whole host of reasons including a lack of data, disagreement over core elements to consider, and complexity. Accumulated state assessments of aquatic systems is an integral component of watershed cumulative effects assessment. The Yukon River is the largest free flowing river in the world and is the fourth largest drainage basin in North America, draining 855,000 km(2) in Canada and the United States. Because of its remote location, it is considered pristine but little is known about its cumulative state. This review identified 7 "hot spot" areas in the Yukon River Basin including Lake Laberge, Yukon River at Dawson City, the Charley and Yukon River confluence, Porcupine and Yukon River confluence, Yukon River at the Dalton Highway Bridge, Tolovana River near Tolovana, and Tanana River at Fairbanks. Climate change, natural stressors, and anthropogenic stresses have resulted in accumulating changes including measurable levels of contaminants in surface waters and fish tissues, fish and human disease, changes in surface hydrology, as well as shifts in biogeochemical loads. This article is the first integrated accumulated state assessment for the Yukon River basin based on a literature review. It is the first part of a 2-part series. The second article (Dubé et al. 2013a, this issue) is a quantitative accumulated state assessment of the Yukon River Basin where hot spots and hot moments are assessed outside of a "normal" range of variability.

Modern carbonate microbialites from an asbestos open pit pond, Yukon, Canada.

Microbialites were discovered in an open pit pond at an abandoned asbestos mine near Clinton Creek, Yukon, Canada. These microbialites are extremely young and presumably began forming soon after the mine closed in 1978. Detailed characterization of the periphyton and microbialites using light and scanning electron microscopy was coupled with mineralogical and isotopic analyses to investigate the mechanisms by which these microbialites formed. The microbialites are columnar in form (cm scale), have an internal spherulitic fabric (mm scale), and are mostly made of aragonite, which is supersaturated in the subsaline pond water. Initial precipitation is seen as acicular aragonite crystals nucleating onto microbial biomass and detrital particles. Continued precipitation entombs benthic diatoms (e.g. Brachysira vitrea), filamentous algae (e.g. Oedogonium sp.), dinoflagellates, and cyanobacteria. The presence of phototrophs at spherulite centers strongly suggests that these microbes play an important initial role in aragonite precipitation. Substantial growth of individual spherulites occurs abiotically through periodic precipitation of aragonite that forms concentric laminations around spherulite centers while pauses in spherulite growth allow for colonization by microbes. Aragonite associated with biomass (δ(13)C = -4.6‰ VPDB) showed a (13)C-enrichment of 0.8‰ relative to aragonite exhibiting no biomass (δ(13)C = -5.4‰ VPDB), which suggests a modest removal of isotopically light dissolved inorganic carbon by phototrophs. The combination of a low sedimentation rate, high calcification rate, and low microbial growth rate appears to result in the formation of these microbialites. The formation of microbialites at an historic mine site demonstrates that an anthropogenically constructed environment can foster microbial carbonate formation.