Fish growth and survival are largely determined by the nutritional quality of their food, and the fish that grow quickly during early life stages are more likely to reproduce. To adequately estimate ...the quality of the prey for fish, it is necessary to understand the trophic links at the base of the food-web. Trophic biomarkers (e.g., stable isotopes and fatty acids) are particularly useful to discriminate and quantify food-web relationships. We explored the connections between plankton food-web components, and the seasonal and spatial dynamics of the trophic biomarkers and how this determines the availability of high-quality prey for juvenile Pacific salmon and Pacific herring in the Strait of Georgia, Canada. We demonstrate that the plankton food-web in the region is largely supported by diatom and flagellate production. We also show that spatial differences in terms of energy transfer efficiency exist in the region. Further, we found that the fatty acid composition of the zooplankton varied seasonally, matching a shift from diatom dominated production in the spring to flagellate dominated production in the summer. This seasonal shift conferred a higher nutritional value to zooplankton in the summer, indicating better quality prey for juvenile salmon and herring during this period.
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•Carbohydrates and phenolics were obtained from straws using pressurized fluids.•Temperature and ethanol concentration influenced biocompound removal.•Optimal biocompounds removal was ...obtained with PAE (20%) at 180 °C and 50 bar.•The PAE improved delignification of barley and canola straws compared to sCW.•Thermal stability of straw residues improved after pressurized fluid treatment.
Canada produces annually vast amounts of barley and canola straws. In this study, barley and canola straws were hydrolyzed using subcritical water (sCW) and pressurized aqueous ethanol (PAE) at 140–220 °C, 50–200 bar and 20–100% (v/v) ethanol concentrations for maximum removal of carbohydrates and phenolics. Total carbohydrates, phenolics, antioxidant activity and brown color formation were quantified via UV-spectrophotometer. Temperature and ethanol concentration were important process parameters for the removal of biocompounds from barley and canola straws. Optimum process conditions for removal of phenolics (45.4 ± 1.8 mg GAE/g barley straw and 52.9 ± 2.0 mg GAE/g canola straw) and carbohydrates (527.6 ± 0.5 mg GE/g barley straw and 442.7 ± 14.8 mg GE/g canola straw) were 180 °C, 50 bar and 20% ethanol. Furthermore, 54 and 45% of total lignin were removed using PAE (20%) from barley and canola straws, respectively. The FT-IR, TG, DTG and SEM analysis confirmed the removal of non-cellulosic materials.
Antler cannibalism in reindeer Mysterud, Atle; Ytrehus, Bjørnar; Tranulis, Michael A ...
Scientific reports,
12/2020, Letnik:
10, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Prion diseases constitute a class of invariably fatal and degenerative encephalopathies. Chronic Wasting Disease (CWD) is a contagious prion disease among cervids, which is spreading and causing ...marked population declines in USA and Canada. The first outbreak of CWD in Europe was discovered in a reindeer population in Norway in 2016. In the worst-case scenario with continental-wide spreading of CWD in Eurasia, an annual harvest of around 4 million cervids is at stake only in Europe, with huge economic and cultural significance. An in situ origin of CWD was suspected, and it appear urgent to identify the likely cause to prevent future emergences. Here, we document the novel phenomenon of extensive antler cannibalism prior to shedding among reindeer in the CWD-infected population. The extent of antler cannibalism increased over the last decades when CWD emerged, and included ingestion of vascularized antlers. Ingestion of tissues from conspecifics is a risk factor for the emergence of prion diseases, where the presence of extensive antler cannibalism opens the intriguing possibility of a 'Kuru-analogue' origin of CWD among the reindeer in Europe. Based on general insight on pathology of prion diseases and strain selection processes, we propose an hypothesis for how contagious CWD may emerge from sporadic CWD under the unique epidemiological conditions we document here. More research is required to document the presence of prions in reindeer antlers, and whether antler cannibalism actually led to a strain selection process and the emergence of a contagious form of CWD from a sporadic form of CWD.
Copyright industries are an important part of the economy, accounting for five to over ten percent of the GDP of certain economies. Studies suggest that the copyright sector has grown faster than the ...entire economy in most countries. However, the author’s earlier study found that Canada’s core copyright-based industries accounted for a smaller share of the economy when compared to those industries in the United States and Europe. This paper examines the factors behind the slower growth of copyright-based industries in Canada. In particular, the paper estimates the growth of the main economic indicators of the core copyright-based industries of Canada and compares them with those of the rest of the economy and with those of the copyright-based industries in the United States. The study also explores the impacts of factors such as exports, foreign direct investment, and information and communication technologies on the productivity of the copyright-based industries. Generalized Method of Moments (GMM) and System GMM methods are used to estimate the models. The study suggests that there is a significant gap between Canada and the United States in terms of value added, employment, investment, and labor productivity growth of core copyright-based industries.
Electricity supply in remote areas of the Russian territory is heavily dependent on diesel sources. Diesel generation imposes an important economic and social burden on the local population, besides ...the environmental impact of greenhouse gas emissions, black carbon and oil spills. Switching to renewable energy could reduce the current economic, social and environmental cost of electricity supply in Russia׳s remote areas. The objective of this paper is to review Russia׳s off-grid renewable energy policy by focusing on the promotion of wind- and solar-diesel hybrid energy in the Russian Arctic. Taking a mainly regulatory perspective, this paper identifies existing barriers to the development of hybrid renewable-diesel investments. Building further on the international experience with the promotion of renewable energy in Arctic climates (e.g., in Alaska and Canada), this paper tests the feasibility of alternative ‘best practice’ mechanisms to support off-grid renewable energy in Russia.
With the centenary of the First World War, communities across Canada arranged commemorations of the war experience to honour local servicemen who, through their triumphs and sacrifices, were ...presented as laying the foundation for a free and independent country. Often overlooked are the triumphs and sacrifices of those who supported those soldiers, and the war effort in general, back at home. The Frontier of Patriotism provides an in-depth look at all aspects of Alberta's involvement in the war, reflecting Albertans' experiences both on the battlefield and on the home front. Contributors of the 40 essays all draw heavily on national and local archival resources. The war is seen through the letters, diaries and memoirs of the individuals who lived through it, as well as through accounts in local newspapers. Readers will come away from this collection with a deeper appreciation of the different ways that the First World War, and its aftermath, shaped the lives of Albertans. For many, these four tumultuous years represented a time of individual valour and of communities pulling together and sacrificing for a noble cause. Yet, for others, the war left disillusionment and anger. Exploring these regional and local stories, as well as the national story, helps us understand the commonalities and distinctiveness of what it means to be Canadian. The Frontier of Patriotism is the most comprehensive treatment of Alberta during these critical, transformational years.
Mercury (Hg) is a toxic element which has increased in marine environments for more than a century, due largely to anthropogenic activities, and biomagnifies in food chains to harmful levels in some ...top predators like waterfowl and seabirds. We analysed total mercury (THg) concentrations in blood, brain and muscle tissue from healthy specimens of 13 coastal and pelagic bird species from eastern and northern Canada to provide a baseline on current concentrations, especially for brain concentrations which are highly underrepresented in the literature. We also examined within and among tissues relationships of THg concentrations within individuals. THg concentrations were generally higher in pelagic species and scavenging gulls, when compared to coastal waterfowl. Brain and muscle tissue had similar concentrations of THg in the birds examined, but both of these tissues had lower concentrations that those found in blood. Our results, and that of a previous study, suggest that body condition has a large influence on blood THg concentrations and should be considered when using blood as a sampling medium. Many of the species we examined had tissue THg above levels known to cause deleterious, sublethal effects in some species.
•Total mercury (THg) was sampled in blood, brain and muscle tissue of 13 species of wild, apparently healthy marine birds.•Muscle and brain THg concentrations approximated a 1:1 ratio, whereas blood THg values were more variable.•Gulls and pelagic seabirds had higher THg concentrations that coastal waterfowl.
Improving the environmental performance of built environments has received wider interest in the recent past. Asset management is an under-utilized strategy to enhance and maintain desired ...environmental performance of a building at low life cycle costs (LCC). Current asset management decision-making methods are not fully capable of incorporating future technological changes and complex time sensitive environmental demands. There is a knowledge gap in incorporating factors such as environmental performance, risk and time sensitivity to foster dynamic asset management decision making. This paper presents a multi-period asset management method for public buildings to minimize LCC and attain climate action goals. A scenario planning approach is used to incorporate future changes in technologies, costs and organizational policies. Risk based prioritization is used to compare and select maintenance alternatives in a given period. Value at risk is used to identify the lowest risk capital planning strategy for an organization. The proposed approach was demonstrated using an operating aquatic centre building in British Columbia, Canada. Three possible future scenario were considered. Proposed method was used to develop multi-period maintenance plans for future scenarios. Based on the analysis, Great Transitions scenario is expected to achieve the least financial risk. The proposed approach enable capital asset planning by complying with changing climate action targets in a stochastic environment.
•A risk based multi-period maintenance planning approach was proposed for public buildings.•This approach incorporates future uncertainties into the building maintenance planning.•Proposed approach was applied to a public aquatic centre building operating in Canada.•This approach assists climate conscious capital asset planning of municipalities.
In this paper, we study the effect of COVID‐19 on the labour market and reported mental health of Canadians. To better understand the effect of the pandemic on the labour market, we build indexes for ...whether workers: (i) are relatively more exposed to disease, (ii) work in proximity to co‐workers, (iii) are essential workers and (iv) can easily work remotely. Our estimates suggest that the impact of COVID‐19 was significantly more severe for workers that work in proximity to co‐workers and those more exposed to disease who are not in the health sector, while the effects are less severe for essential workers and workers that can work remotely. Last, using the Canadian Perspective Survey Series, we observe that reported mental health is significantly lower among some of the most affected workers such as women and less‐educated workers. We also document that those who were absent from work because of COVID‐19 are more concerned with meeting their financial obligations and with losing their job than those who continue working outside their home.
Résumé
Conséquences économiques de la COVID‐19 à court terme : tâches professionnelles et santé mentale au Canada. Dans cet article, nous étudions les répercussions de la COVID‐19 sur le marché de l'emploi et la santé mentale déclarée des Canadiens. Afin de mieux comprendre les effets de la pandémie sur le marché du travail, nous avons développé des indices permettant de déterminer si les travailleurs : 1) sont relativement plus exposés à la maladie; 2) exercent leur activité à proximité de leurs collègues; 3) sont essentiels; 4) peuvent facilement travailler à distance. D'après nos estimations, les conséquences de la COVID‐19 se sont avérées nettement plus sévères chez les travailleurs exerçant à proximité de leurs collègues ainsi que les professionnels (hors secteur médical) davantage exposés à la maladie, mais moins importantes chez les travailleurs essentiels et les télétravailleurs. Enfin, en nous appuyant sur l'une des enquêtes sur les perspectives canadiennes, nous observons que la santé mentale déclarée est nettement inférieure chez les travailleurs les plus touchés, notamment les femmes et les travailleurs moins instruits. Nous montrons également que les personnes écartées de leur travail en raison de la COVID‐19 se soucient davantage du respect de leurs obligations financières et de la perte de leur emploi par rapport à celles qui ont pu continuer à travailler hors de leur domicile.
Railways are a major source of direct mortality for many populations of large mammals, but they have been less studied or mitigated than roads. We evaluated temporal and spatial factors affecting ...mortality risk using 646 railway mortality incidents for 11 mammal species collected over 24 years throughout Banff and Yoho National Parks, Canada. We divided species into three guilds (bears, other carnivores, and ungulates), compared site attributes of topography, land cover, and train operation between mortality and paired random locations at four spatial scales, and described temporal patterns or mortality. Mortality risk increased across multiple guilds and spatial scales with maximum train speed and higher track curvature, both suggesting problems with train detection, and in areas with high proximity to and amount of water, both suggesting limitations to animal movement. Mortality risk was also correlated, but more varied among guilds and spatial scales, with shrub cover, topographic complexity, and proximity to sidings and roads. Seasonally, mortality rates were highest in winter for ungulates and other carnivores, and in late spring for bears, respectively. Our results suggest that effective mitigation could address train speed or detectability by wildlife, especially at sites with high track curvature that are near water or attractive habitat.
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