The mining industry in Canada north of the 55th parallel : a maritime traffic generator?

This paper reviews and assesses the state of the mining industry in Canada north of the 55th parallel. It aims to describe and monitor to what extent the development of mining projects in the Canadian Arctic are likely to trigger and expand commercial shipping in Canadian Arctic waters. Based on a literature and statistical review of publicly available information, the results show that only 3 actives mines out of 10 rely on a shipping logistics through Canadian Arctic waters to export raw materials. Once active and in operation, seven other mining projects will likely increase commercial shipping activities through Canadian Arctic waters, while it remains difficult to quantify precisely. However, this paper argues that the viability of northern mineral development is related to a wide variety of conditions including access to capital and foreign direct investment for the development and construction of infrastructure, international market conditions, and shifting demand which largely determines commodity prices and the profitability of a project, harsh environmental conditions, and high operating costs in northern latitudes. In this context, there is no Arctic mining rush and all these factors contribute to increasing the cost of doing business in the north

A Standalone FPGA-based Miner for Lyra2REv2 Cryptocurrencies

Lyra2REv2 is a hashing algorithm that consists of a chain of individual hashing algorithms, and it is used as a proof-of-work function in several cryptocurrencies. The most crucial and exotic hashing algorithm in the Lyra2REv2 chain is a specific instance of the general Lyra2 algorithm. This work presents the first hardware implementation of the specific instance of Lyra2 that is used in Lyra2REv2. Several properties of the aforementioned algorithm are exploited in order to optimize the design. In addition, an FPGA-based hardware implementation of a standalone miner for Lyra2REv2 on a Xilinx Multi-Processor System on Chip is presented. The proposed Lyra2REv2 miner is shown to be significantly more energy efficient than both a GPU and a commercially available FPGA-based miner. Finally, we also explain how the simplified Lyra2 and Lyra2REv2 architectures can be modified with minimal effort to also support the recent Lyra2REv3 chained hashing algorithm.Comment: 13 pages, accepted for publication in IEEE Trans. Circuits Syst. I. arXiv admin note: substantial text overlap with arXiv:1807.0576

Arctic routes opening up : strategies and perceptions of the bulk shipping industry

La fonte des glaces arctiques a suscité un intérêt renouvelé pour les routes arctiques dans les milieux de la recherche et dans les média. Plusieurs travaux se sont intéressés au secteur du conteneur, mais peu abordent spécifiquement le secteur du vrac. Une enquête auprès de plusieurs transporteurs maritimes du secteur du vrac, menée en 2010 puis en 2015, a cependant permis de souligner le faible intérêt des entreprises de ce marché pour le transit arctique.The melting of Arctic sea ice has sparked a renewed interest for Arctic routes in the research community and in the media. Several studies have focused on the container sector, but few specifically addressed the bulk sector. A survey of several bulk shipping companies, conducted in 2010 and 2015, however, highlighted the low interest of companies in this market for Arctic transi

Characterization of in vitro engineered human adipose tissues : relevant adipokine secretion and impact of TNF-α

Representative modelling of human adipose tissue functions is central to metabolic research. Tridimensional models able to recreate human adipogenesis in a physiological tissue-like context in vitro are still scarce. We describe the engineering of white adipose tissues reconstructed from their cultured adipose-derived stromal precursor cells. We hypothesize that these reconstructed tissues can recapitulate key functions of AT under basal and pro-inflammatory conditions. These tissues, featuring human adipocytes surrounded by stroma, were stable and metabolically active in long-term cultures (at least 11 weeks). Secretion of major adipokines and growth factors by the reconstructed tissues was determined and compared to media conditioned by human native fat explants. Interestingly, the secretory profiles of the reconstructed adipose tissues indicated an abundant production of leptin, PAI-1 and angiopoietin-1 proteins, while higher HGF levels were detected for the human fat explants. We next demonstrated the responsiveness of the tissues to the pro-inflammatory stimulus TNF-α, as reflected by modulation of MCP-1, NGF and HGF secretion, while VEGF and leptin protein expression did not vary. TNF-α exposure induced changes in gene expression for adipocyte metabolism-associated mRNAs such as SLC2A4, FASN and LIPE, as well as for genes implicated in NF-κB activation. Finally, this model was customized to feature adipocytes representative of progressive stages of differentiation, thereby allowing investigations using newly differentiated or more mature adipocytes. In conclusion, we produced tridimensional tissues engineered in vitro that are able to recapitulate key characteristics of subcutaneous white adipose tissue. These tissues are produced from human cells and their neo-synthesized matrix elements without exogenous or synthetic biomaterials. Therefore, they represent unique tools to investigate the effects of pharmacologically active products on human stromal cells, extracellular matrix and differentiated adipocytes, in addition to compounds modulating adipogenesis from precursor cells

Engineering of hrAT featuring adipocytes representative of various stages of differentiation.

<p>(A) Schematic representation of the induction schemes leading to the production of the hrAT shown in (C). (B) Intracellular lipid quantification following Oil Red O staining of adipose sheets reconstructed according to static or dynamic culture conditions. While the induction of adipogenesis was performed at different times (day 7, 14 or 21) of culture in presence of AsA, Oil Red O staining was carried out after a fixed period of 14 days during which lipid accumulation proceeded. *<i>P</i>≤0.05, One-way ANOVA followed by Tukey’s post-hoc test; ^###<i>P</i> = 0.0003, ^&&<i>P</i> = 0.0013, paired <i>t</i>-tests between dynamic and static conditions at a given day of induction. (C) Histological cross-sections of hrCT (no adipocytes) and hrAT featuring smaller or more developed adipocytes according to the day at which induction of adipogenesis was performed under dynamic culture conditions. Masson’s trichrome staining on paraffin-embedded hrAT samples (left) show the presence of numerous adipocytes (void spaces) and important ECM content (blue), while Oil Red O staining (right) on formol-fixed cryosections reveals the accumulation of intracellular lipids by the developing adipocytes. Bars = 100 μm.</p

Long-term stability of the hrAT <i>in vitro</i>.

<p>(A) Mean surface area of the adipocytes over the culture period as measured from histological sections of hrAT harvested after 28, 49 or 81 days of <i>in vitro</i> differentiation. (B) Frequency distribution of adipocyte cell surface area according to the number of days the tissues were maintained in culture after adipogenic induction. Mean ± SEM. One-way ANOVA followed by Tukey’s post-hoc tests were performed and the significance is indicated in reference to day 28 (*) or day 49 (#). ***<i>P</i>≤0.001, **<i>P</i>≤0.01, * and ^#<i>P</i>≤0.05. (C) Kinetics of Ang-1 secretion in media conditioned by reconstructed cell sheets maintained in culture up to 49 days. Connective sheets were produced using the same cells as adipose sheets but without the adipogenic induction step. Results are expressed as ng/ml/48 h per sheet of 3.5 cm². Data from cell sheets engineered from three distinct cell populations is represented (N = 3, n = 2–3 for each time-point). Mean ± SD, # indicates statistical difference between connective and adipose sheets at each time-point (<i>P</i>≤0.05, unpaired <i>t</i>-tests) while asterisks (*) indicate the comparison between consecutive weeks within the same cell population. & indicates that all three populations are significantly different between consecutive weeks. One-way ANOVA followed by Tukey’s post-hoc test. **** <i>P</i>≤0.0001, *** <i>P</i>≤0.001, **<i>P</i>≤0.01, * and ^&<i>P</i>≤0.05.</p

Description of AT used for organotypic cultures and/or tissue reconstruction.

<p>*: Values are indicated as mean (SD) when applicable.</p><p>&: indicates tissues from male donors.</p><p>#: indicates data available for both AT explants and tissues reconstructed using the cells extracted from adipose tissue from the same donor.</p><p>Description of AT used for organotypic cultures and/or tissue reconstruction.</p

Effects of TNF-α on adipokine secretion by reconstructed tissues and AT explants.

<p>(A) Dose-dependent release of MCP-1 after exposure to TNF-α. Adipose cell sheets were incubated for 24 h in presence of 10 or 100 ng/ml of TNF-α and the conditioned media were analyzed by ELISA assays. One-way ANOVA followed by Tukey’s post-hoc test. ***<i>P</i>≤0.001 compared to control, ^##<i>P</i>≤0.01 compared to 10 ng/ml TNF-α. (B) Fold increase protein expression over control for MCP-1, free NGF, HGF, VEGF and leptin following a 24 h exposition of adipose sheets to 10 or 100 ng/ml TNF-α. (C) Fold increase protein expression over control for MCP-1, HGF and VEGF following a 24 h exposition of connective sheets to 10 or 100 ng/ml TNF-α. For each molecule, one-sample <i>t</i>-tests were performed in reference to untreated sheets (ratio of 1). For B and C, One-way ANOVA followed by Dunnett’s post-hoc test ****<i>P</i>≤0.0001, ***<i>P</i>≤0.001, **<i>P</i>≤0.01. (D) Comparative amounts (ng/ml) of MCP-1, HGF and VEGF secreted by the connective and adipose cell sheets following a 24 h exposure to 10 ng/ml TNF-α. Dashed lines within each column indicate the basal level of mock-treated connective and adipose sheets for the corresponding secreted protein. # indicates statistical significance for these basal levels between connective and adipose sheets while asterisks (*) indicate significance between tissue types. ****<i>P</i>≤0.0001, **<i>P</i>≤0.01, *<i>P</i>≤0.05. Note that leptin is not produced by connective sheets or hrCT. (E) Fold increase protein expression over control for MCP-1, HGF, VEGF and leptin following a 24 h exposition of human AT explants to 10 ng/ml TNF-α. Data normalization was performed according to the weight of the explants.</p

Primer sequences and gene description.

<p>Primer sequences and gene description.</p