•Many models in the literature have been published to try and assess the profitability of shipping in the Arctic.•Their conclusions differ widely depending on the selected parameters.•Most ...simulations focus on direct cost parameters but fail to consider market issues.•A new model shows some Asian ports can be served profitably along an Arctic route.•The most important factors for a profitable Arctic service seem to be transit speed and load factor.
Arctic sea routes have for long attracted interest from observers and shipping companies because of their shorter distances between the Atlantic and the Pacific. The prevalence of sea ice prevented the real development of a significant traffic, but did not prevent research from trying to assess the economic viability of these routes. With the actual present melting of sea ice in the Arctic, this effort at modeling the profitability of Arctic shipping routes received a new impetus. However, the conclusions of these studies vary widely, depending on the chosen parameters and their value. What can be said of these models, from 1991 until 2013, and to what extent can a model be drawn, capitalizing on twenty years of simulations?
Despite many discoveries over the past 20 years regarding the etio-pathogenesis of periodontal and peri-implant diseases, as well as significant advances in our understanding of microbial biofilms, ...the incidence of these pathologies still continues to rise. This review presents a general overview of the main protagonists and phenomena involved in oral health and disease. A special emphasis on the role of certain keystone pathogens in periodontitis and peri-implantitis is underlined. Their capacity to bring a dysregulation of the homeostasis with their host and the microbial biofilm lifestyle are also discussed. Finally, the current treatment principles of periodontitis and peri-implantitis are presented and their limits exposed. This leads to realize that new strategies must be developed and studied to overcome the shortcomings of existing approaches.
► Provides insight on the industry’s negative industry perception of the future of Artic shipping. ► Among shipping companies in the Northern hemisphere, there is a very low interest. ► Among ...container shipping firms, a poor interest for Arctic transit. ► And a reasonable interest just for destinational traffic among bulk shipping firms. ► Confirms there is a debatable profitability for transit along Arctic routes. ► There is no significant current upsurge in orders for ice-class ships orders for the Arctic.
The seasonal melting of sea ice in the Arctic Ocean, which has been confirmed for several summers in a row and is widely documented, has become a hot topic in the media. It is fuelling many speculative scenarios about the purported renewal of a “cold war”, or even an actual armed conflict, in the Arctic, for the control of both its natural resources and its sea routes.
The melting sea ice is indeed giving a second wind to projects, abandoned in the 19th century, to find shorter sea routes between Europe and Asia. A look at the map shows the savings in distance that can be achieved with the Arctic routes: for example, a trip between London and Yokohama through the Northwest Passage is 15,700km and 13,841km through the Northeast Passage, which is significantly shorter than the route through Suez (21,200km) or Panama (23,300km).2Data calculated by the author using Mapinfo GIS software.2 These findings fuel the idea that these Arctic routes, because they are shorter, are bound to attract abundant through traffic, and consequently will become a major political issue. Amid the media widespread image of a future maritime highway across Arctic seas, even some scientists yield to the popular image and assert, without proof, that Arctic traffic is set to increase rapidly.3For instance, «Because the Northwest Passage is about to become an alternative route to the Panama Canal, the volume of use within the passage will likely exceed 3000 vessels a year», Roston, 2009. The Northwest Passage’s Emergence as an International Highway. Southwestern Journal of International Law, 15, p. 469.3 Beyond the seemingly decisive advantage of Arctic routes, however, there remain many obstacles to navigation (Lasserre, 2010d). In addition, these scenarios for the development of marine traffic in the Arctic remain highly speculative and are not based on an analysis of shipowners’ perceptions, which is the goal of this paper.
This article will thus present the results of an empirical survey conducted among shipping companies to determine their interest in developing activities in the Arctic. Besides examining the potential development of shipping in Arctic routes, this research must be replaced in the context of intense competition between shippers, competition that makes both service reliability and costs of transport paramount. In this competition structure, the benefits of established routes between major hubs seems to prevail, so that new routes have difficulty being established.
Three major and very different controversies oppose the countries of the Arctic. First, there is the question of the status of the potential maritime routes of the Northwest and Northeast Passages, ...while scenarios predict an increase in navigation. Next, there is the question of the extension of economic sovereignty over the continental shelves, beyond the 200 nautical mile line, and the border disputes that overlap could give rise to. Finally, fueled by the concern of the Arctic States to assert their control over the maritime areas that are freeing from the ice, security policies sometimes appear as a militarization of the Arctic, in particular for Russia and, for a time, for Canada. These three controversies differ as much in stakes as in the fact of changing alliance games. But do these phenomena really reflect a surge in geopolitical issues for the Arctic ?
China’s Arctic Ambitions and What They Mean for Canada is one of the first in-depth studies of China’s increasing interest in the Arctic. It offers a holistic approach to understanding Chinese ...motivations and the potential impacts of greater Chinese presence in the circumpolar region, exploring resource development, shipping, scientific research, governance, and security. Drawing on extensive research in Chinese government documentation, business and media reports, and current academic literature, this timely volume eschews the traditional assumption that Chinese actions are unified and monolithic in their approach to Arctic affairs. Instead, it offers a careful analysis of the different, and often competing, interests and priorities of Chinese government and industry. Analyzing Chinese interests and activities from a Canadian perspective, the book provides an unparalleled point of reference to discuss the implications for the Canadian and broader circumpolar North.
Peroxisome proliferator activated receptor α (PPARα) acts as a fatty acid sensor to orchestrate the transcription of genes coding for rate-limiting enzymes required for lipid oxidation in ...hepatocytes. Mice only lacking Pparα in hepatocytes spontaneously develop steatosis without obesity in aging. Steatosis can develop into non alcoholic steatohepatitis (NASH), which may progress to irreversible damage, such as fibrosis and hepatocarcinoma. While NASH appears as a major public health concern worldwide, it remains an unmet medical need. In the current study, we investigated the role of hepatocyte PPARα in a preclinical model of steatosis. For this, we used High Fat Diet (HFD) feeding as a model of obesity in C57BL/6 J male Wild-Type mice (WT), in whole-body Pparα
deficient mice (Pparα
) and in mice lacking Pparα only in hepatocytes (Pparα
). We provide evidence that Pparα deletion in hepatocytes promotes NAFLD and liver inflammation in mice fed a HFD. This enhanced NAFLD susceptibility occurs without development of glucose intolerance. Moreover, our data reveal that non-hepatocytic PPARα activity predominantly contributes to the metabolic response to HFD. Taken together, our data support hepatocyte PPARα as being essential to the prevention of NAFLD and that extra-hepatocyte PPARα activity contributes to whole-body lipid homeostasis.
Changes in lifestyle are suspected to have strongly influenced the current obesity epidemic. Based on recent experimental, clinical, and epidemiological work, it has been proposed that some food ...contaminants may exert damaging effects on endocrine and metabolic functions, thereby promoting obesity and associated metabolic diseases such as nonalcoholic fatty liver disease (NAFLD). In this work, we investigated the effect of one suspicious food contaminant, bisphenol A (BPA), in vivo. We used a transcriptomic approach in male CD1 mice exposed for 28 days to different doses of BPA (0, 5, 50, 500, and 5,000 μg/kg/day) through food contamination. Data analysis revealed a specific impact of low doses of BPA on the hepatic transcriptome, more particularly on genes involved in lipid synthesis. Strikingly, the effect of BPA on the expression of de novo lipogenesis followed a nonmonotonic dose‐response curve, with more important effects at lower doses than at the higher dose. In addition to lipogenic enzymes (Acc, Fasn, Scd1), the expression of transcription factors such as liver X Receptor, the sterol regulatory element binding protein‐1c, and the carbohydrate responsive element binding protein that govern the expression of lipogenic genes also followed a nonmonotonic dose‐response curve in response to BPA. Consistent with an increased fatty acid biosynthesis, determination of fat in the liver showed an accumulation of cholesteryl esters and of triglycerides. Conclusion: Our work suggests that exposure to low BPA doses may influence de novo fatty acid synthesis through increased expression of lipogenic genes, thereby contributing to hepatic steatosis. Exposure to such contaminants should be carefully examined in the etiology of metabolic diseases such as NAFLD and nonalcoholic steatohepatitis. (Hepatology 2012)
Epidemiology evidenced the Bisphenol A (BPA), a chemical found in daily consumer products, as an environmental contributor to obesity and type II diabetes (T2D) in Humans. However, the BPA-mediated ...effects supporting these metabolic disorders are still unknown. Knowing that obesity and T2D are associated with low-grade inflammation and gut dysbiosis, we performed a longitudinal study in mice to determine the sequential adverse effects of BPA on immune system and intestinal microbiota that could contribute to the development of metabolic disorders. We observed that perinatal exposure to BPA (50 µg/kg body weight/day) induced intestinal and systemic immune imbalances at PND45, through a decrease of Th1/Th17 cell frequencies in the lamina propria concomitant to an increase of splenic Th1/Th17 immune responses. These early effects are associated with an altered glucose sensitivity, a defect of IgA secretion into faeces and a fall of faecal bifidobacteria relative to control mice. Such BPA-mediated events precede infiltration of pro-inflammatory M1 macrophages in gonadal white adipose tissue appearing with ageing, together with a decreased insulin sensitivity and an increased weight gain. Our findings provide a better understanding of the sequential events provoked by perinatal exposure to BPA that could support metabolic disorder development in later life.
The governments of Canada and Denmark signed a historic agreement on Hans Island on 14 June 2022. Although most of the agreement was devoted to the resolution of the Hans Island dispute, it also ...settled other issues. We argue that provisions on mobility and the continental shelf in the Labrador Sea give rise to interesting precedents that could have far-reaching effects for northerners. The agreement on enhanced mobility could represent a first step in a more ambitious process of facilitating Inuit mobility across Nunavut and Greenland, while the settlement on the continental shelf illustrates how states could collaborate on other continental shelf cases, including the continental shelf in the Central Arctic Ocean.
Male and female mule ducks were subjected to a force-feeding diet to induce liver steatosis as it is generally done only with male ducks for the production of foie gras. The different biochemical ...measurements indicated that the course of hepatic steatosis development was present in both sexes and associated with a huge increase in liver weight mainly due to the synthesis and accumulation of lipids in hepatocytes. In livers of male and female ducks, this lipid accumulation was associated with oxidative stress and hypoxia. However, certain specific modifications (kinetics of lipid droplet development and hepatic inflammation) indicate that female ducks may tolerate force-feeding less well, at least at the hepatic level. This is in contradiction with what is generally reported concerning hepatic steatosis induced by dietary disturbances in mammals but could be explained by the very specific conditions imposed by force-feeding. Despite this, force-feeding female ducks seems entirely feasible, provided that the final quality of the product is as good as that of the male ducks, which will remain to be demonstrated in future studies.
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