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https://www.readbyqxmd.com/read/28811875/ecosystem-size-predicts-eco-morphological-variability-in-a-postglacial-diversification
#1
Hans Recknagel, Oliver E Hooker, Colin E Adams, Kathryn R Elmer
Identifying the processes by which new phenotypes and species emerge has been a long-standing effort in evolutionary biology. Young adaptive radiations provide a model to study patterns of morphological and ecological diversification in environmental context. Here, we use the recent radiation (ca. 12k years old) of the freshwater fish Arctic charr (Salvelinus alpinus) to identify abiotic and biotic environmental factors associated with adaptive morphological variation. Arctic charr are exceptionally diverse, and in postglacial lakes there is strong evidence of repeated parallel evolution of similar morphologies associated with foraging...
August 2017: Ecology and Evolution
https://www.readbyqxmd.com/read/28811530/evidence-for-ice-ocean-albedo-feedback-in-the-arctic-ocean-shifting-to-a-seasonal-ice-zone
#2
Haruhiko Kashiwase, Kay I Ohshima, Sohey Nihashi, Hajo Eicken
Ice-albedo feedback due to the albedo contrast between water and ice is a major factor in seasonal sea ice retreat, and has received increasing attention with the Arctic Ocean shifting to a seasonal ice cover. However, quantitative evaluation of such feedbacks is still insufficient. Here we provide quantitative evidence that heat input through the open water fraction is the primary driver of seasonal and interannual variations in Arctic sea ice retreat. Analyses of satellite data (1979-2014) and a simplified ice-upper ocean coupled model reveal that divergent ice motion in the early melt season triggers large-scale feedback which subsequently amplifies summer sea ice anomalies...
August 15, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28807609/cspb-of-an-arctic-bacterium-polaribacter-irgensii-kopri-22228-confers-extraordinary-freeze-tolerance
#3
Youn Hong Jung, Yoo Kyung Lee, Hong Kum Lee, Kyunghee Lee, Hana Im
Freezing temperatures are a major challenge for life at the poles. Decreased membrane fluidity, uninvited secondary structure formation in nucleic acids, and protein cold-denaturation all occur at cold temperatures. Organisms adapted to polar regions possess distinct mechanisms that enable them to survive in extremely cold environments. Among the cold-induced proteins, cold shock protein (Csp) family proteins are the most prominent. A gene coding for a Csp-family protein, cspB, was cloned from an arctic bacterium, Polaribacter irgensii KOPRI 22228, and overexpression of cspB greatly increased the freeze-survival rates of Escherichia coli hosts, to a greater level than any previously reported Csp...
July 31, 2017: Brazilian Journal of Microbiology: [publication of the Brazilian Society for Microbiology]
https://www.readbyqxmd.com/read/28805981/noncompetitive-inhibition-of-human-cyp2c9-in%C3%A2-vitro-by-a-commercial-rhodiola-rosea-product
#4
Ole Kristian Forstrønen Thu, Olav Spigset, Bent Hellum
A commercial Rhodiola rosea (R. rosea) product has previously demonstrated CYP2C9 inhibition in humans. The purpose of this study was to provide in vitro inhibitory data for this particular interaction and to classify the mechanism of the interaction. Another aim was to examine the in vitro influence of ethanol on the CYP2C9 activity. Human CYP2C9 (wild type) isolated from a baculovirus-infected cell system was incubated with 0.8 μmol/L losartan for 20 min. Sulfaphenazole was used as a positive control...
August 2017: Pharmacology Research & Perspectives
https://www.readbyqxmd.com/read/28803190/legacy-and-new-halogenated-persistent-organic-pollutants-in-polar-bears-from-a-contamination-hotspot-in-the-arctic-hudson-bay-canada
#5
R J Letcher, A D Morris, M Dyck, E Sverko, E J Reiner, D A D Blair, S G Chu, L Shen
A large and complex suite of 295 legacy and new halogenated persistent organic pollutants (POPs) were investigated in fat or liver tissue samples of polar bears collected in 2013-2014 from Southern (SHB) and Western (WHB) subpopulations of the Canadian Arctic contaminants hotspot of Hudson Bay. A total of 210 POPs were detected and/or quantifiable with some frequency in all fat or liver samples. POP profile and concentration differences were investigated both within (e.g. age and sex) and between the two subpopulations...
August 10, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28803149/concentrations-of-polycyclic-aromatic-hydrocarbons-and-trace-elements-in-arctic-soils-a-case-study-in-svalbard
#6
Montse Marquès, Jordi Sierra, Tatiana Drotikova, Montse Mari, Martí Nadal, José L Domingo
A combined assessment on the levels and distribution profiles of polycyclic aromatic hydrocarbons (PAHs) and trace elements in soils from Pyramiden (Central Spitsbergen, Svalbard Archipelago) is here reported. As previously stated, long-range atmospheric transport, coal deposits and previous mining extractions, as well as the stack emissions of two operative power plants at this settlement are considered as potential sources of pollution. Eight top-layer soil samples were collected and analysed for the 16 US EPA priority PAHs and for 15 trace elements (As, Be, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Sn, Tl, V and Zn) during late summer of 2014...
August 10, 2017: Environmental Research
https://www.readbyqxmd.com/read/28802692/de-novo-transcriptome-assembly-and-rna-seq-expression-analysis-in-blood-from-beluga-whales-of-bristol-bay-ak
#7
Jeanine S Morey, Kathy A Burek Huntington, Michelle Campbell, Tonya M Clauss, Caroline E Goertz, Roderick C Hobbs, Denise Lunardi, Amanda J Moors, Marion G Neely, Lori H Schwacke, Frances M Van Dolah
Assessing the health of marine mammal sentinel species is crucial to understanding the impacts of environmental perturbations on marine ecosystems and human health. In Arctic regions, beluga whales, Delphinapterus leucas, are upper level predators that may serve as a sentinel species, potentially forecasting impacts on human health. While gene expression profiling from blood transcriptomes has widely been used to assess health status and environmental exposures in human and veterinary medicine, its use in wildlife has been limited due to the lack of available genomes and baseline data...
August 9, 2017: Marine Genomics
https://www.readbyqxmd.com/read/28802107/historical-and-future-trends-in-global-source-receptor-relationships-of-mercury
#8
Long Chen, Wei Zhang, Yanxu Zhang, Yindong Tong, Maodian Liu, Huanhuan Wang, Han Xie, Xuejun Wang
Growing concern about the risk associated with increasing environmental mercury (Hg) concentrations has resulted in a focus on the relationships between intercontinental emitted and accumulated Hg. We use a global biogeochemical Hg model with 8 continental regions and a global ocean to evaluate the legacy impacts of historical anthropogenic releases (2000BCE to 2008AD) on global source-receptor relationships of Hg. Legacy impacts of historical anthropogenic releases are confirmed to be significant on the source-receptor relationships according to our results...
August 9, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28801968/warming-of-subarctic-waters-accelerates-development-of-a-key-marine-zooplankton-calanus-finmarchicus
#9
Agata Weydmann, Waldemar Walczowski, Jacob Carstensen, Slawomir Kwasniewski
Recent observations confirm the rising temperatures of Atlantic waters transported into the Arctic Ocean via the West Spitsbergen Current (WSC). We studied the overall abundance and population structure of the North Atlantic keystone zooplankton copepod Calanus finmarchicus, which is the main prey for pelagic fish and some seabirds, in relation to selected environmental variables in this area between 2001 and 2011, when warming in the Arctic and Subarctic was particularly pronounced. Sampling within a three-week time window each summer demonstrated that trends in the overall abundance of C...
August 12, 2017: Global Change Biology
https://www.readbyqxmd.com/read/28798916/risk-benefit-assessment-of-monomethylmercury-and-omega-3-fatty-acid-intake-for-ringed-seal-consumption-with-particular-emphasis-on-vulnerable-populations-in-the-western-canadian-arctic
#10
Lena Gmelch, Holger Hintelmann, Brendan Hickie, Hermine Kienberger, Gary Stern, Michael Rychlik
Many northern Inuit communities rely on traditional food as major source of nourishment. An essential part of the traditional Arctic diet is marine mammals such as ringed seals or beluga. Being top predators, these animals are often highly contaminated with various toxins. In contrast, some tissues of marine mammals are also characterized by high amounts of n3-PUFAs (omega-3 polyunsaturated fatty acids). Here, we try to balance the risks associated with the consumption of different tissue types of ringed seals in terms of the neurotoxin monomethylmercury (MMHg) with the benefits of consumption due to high n3-PUFA concentrations...
2017: Frontiers in Nutrition
https://www.readbyqxmd.com/read/28797773/methyl-propiolate-and-3-butynone-starting-points-for-synthesis-of-amphiphilic-1-2-3-triazole-peptidomimetics-for-antimicrobial-evaluation
#11
Thomas A Bakka, Morten B Strøm, Jeanette H Andersen, Odd R Gautun
A library of 29 small 1,4-substituted 1,2,3-triazoles was prepared for studies of antimicrobial activity. The pharmacophore model investigated with these substrates was based on small peptidomimetics of antimicrobial peptides and antimicrobials isolated from marine organisms from sub-arctic regions. Using methyl 1,2,3-triazole-carboxylates and 1,2,3-triazole methyl ketones prepared through "click" chemistry we were able to synthesize the different cationic amphiphiles through three steps or less. Several structural modifications to the lipopohilic side and hydrophilic sides of the amphiphiles were investigated and compared with regards to antimicrobial activity and cytotoxicity in particular...
July 29, 2017: Bioorganic & Medicinal Chemistry
https://www.readbyqxmd.com/read/28795157/acanthoecid-choanoflagellates-from-the-atlantic-arctic-region-a-baseline-study
#12
Helge Abildhauge Thomsen, Jette Buch Østergaard
The examination and statistical analysis of loricate choanoflagellate material collected from Greenland waters during the period 1988-1998 represents a de facto baseline study of heterotrophic nanoflagellates from the Atlantic Arctic Region. The geographic sites sampled are Disko Bay (West Greenland) and the high-arctic North-East Water (NEW) and North Water (NOW) polynya. The analyses encompass close to 50 taxa. Some of these are described as new species, i.e. Acanthocorbis glacialis, A. reticulata and Diaphanoeca dilatanda...
July 2017: Heliyon
https://www.readbyqxmd.com/read/28793404/nutrient-and-mercury-transport-in-a-sub-arctic-ladder-fen-peatland-subjected-to-simulated-wastewater-discharges
#13
C P R McCarter, B A Branfireun, J S Price
Safely treating wastewater in remote communities and mining operations in sub-arctic Canada is critical to protecting the surrounding aquatic ecosystems. Undisturbed fen peatlands have been used to minimize the release of contaminants to the aquatic ecosystems; however, there is a limited understanding of wastewater transport or polishing in undisturbed fen peatlands. To elucidate these processes, a small (9800m(2), ~250m long) ladder fen was continuously injected with a wastewater surrogate derived from a custom fertilizer blend and 38m(3)day(-1) of water for 51days...
August 5, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28782014/decreasing-cloud-cover-drives-the-recent-mass-loss-on-the-greenland-ice-sheet
#14
Stefan Hofer, Andrew J Tedstone, Xavier Fettweis, Jonathan L Bamber
The Greenland Ice Sheet (GrIS) has been losing mass at an accelerating rate since the mid-1990s. This has been due to both increased ice discharge into the ocean and melting at the surface, with the latter being the dominant contribution. This change in state has been attributed to rising temperatures and a decrease in surface albedo. We show, using satellite data and climate model output, that the abrupt reduction in surface mass balance since about 1995 can be attributed largely to a coincident trend of decreasing summer cloud cover enhancing the melt-albedo feedback...
June 2017: Science Advances
https://www.readbyqxmd.com/read/28781189/-90-sr-and-137-cs-in-arctic-echinoderms
#15
Michał Saniewski, Tomasz Borszcz
Radionuclides in the Arctic echinoderms have seldom been studied despite their considerable environmental importance. This manuscript covers the results of (90)Sr and (137)Cs measurements in common echinoderm taxa collected from the Svalbard Bank in the Barents Sea and from two High-Arctic fjords (Isfjorden and Magdalenefjorden). We focused on the echinoid, Strongylocentrotus droebachiensis, the asteroid, Henricia sanguinolenta, and the ophiuroid, Ophiopolis aculeata. For all echinoderms, the analysis revealed a negative correlation between (90)Sr activity and the mass...
August 4, 2017: Marine Pollution Bulletin
https://www.readbyqxmd.com/read/28776870/marine-terminating-glaciers-sustain-high-productivity-in-greenland-fjords
#16
Lorenz Meire, John Mortensen, Patrick Meire, Thomas Juul-Pedersen, Mikael K Sejr, Søren Rysgaard, Rasmus Nygaard, Philippe Huybrechts, Filip J R Meysman
Accelerated mass loss from the Greenland ice sheet leads to glacier retreat and an increasing input of glacial meltwater to the fjords and coastal waters around Greenland. These high latitude ecosystems are highly productive and sustain important fisheries, yet it remains uncertain how they will respond to future changes in the Arctic cryosphere. Here we show that marine-terminating glaciers play a crucial role in sustaining high productivity of the fjord ecosystems. Hydrographic and biogeochemical data from two fjord systems adjacent to the Greenland ice sheet, suggest that marine ecosystem productivity is very differently regulated in fjords influenced by either land-terminating or marine-terminating glaciers...
August 4, 2017: Global Change Biology
https://www.readbyqxmd.com/read/28770060/stocking-activities-for-the-arctic-charr-in-lake-geneva-genetic-effects-in-space-and-time
#17
Romain Savary, Christophe Dufresnes, Alexis Champigneulle, Arnaud Caudron, Sylvain Dubey, Nicolas Perrin, Luca Fumagalli
Artificial stocking practices are widely used by resource managers worldwide, in order to sustain fish populations exploited by both recreational and commercial activities, but their benefits are controversial. Former practices involved exotic strains, although current programs rather consider artificial breeding of local fishes (supportive breeding). Understanding the complex genetic effects of these management strategies is an important challenge with economic and conservation implications, especially in the context of population declines...
July 2017: Ecology and Evolution
https://www.readbyqxmd.com/read/28764521/a-portable-methane-sampling-system-for-radiocarbon-based-bioportion-measurements-and-environmental-ch4-sourcing-studies
#18
V Palonen, J Uusitalo, E Seppälä, M Oinonen
Radiocarbon measurements can be used to deduce the proportion of renewable to fossil carbon in materials. While these biofraction measurements are performed routinely on solid and liquid substances, measurements of gaseous samples, such as methane, are still scarce. As a pioneering effort, we have developed a field-capable sampling system for the selective capture of CH4 for radiocarbon-concentration measurements. The system allows for biofraction measurements of methane by accelerator mass spectrometry. In environmental research, radiocarbon measurements of methane can be used for fingerprinting different sources of methane emissions...
July 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/28762048/pharmaceuticals-and-personal-care-products-ppcps-in-arctic-environments-indicator-contaminants-for-assessing-local-and-remote-anthropogenic-sources-in-a-pristine-ecosystem-in-change
#19
Roland Kallenborn, Eva Brorström-Lundén, Lars-Otto Reiersen, Simon Wilson
A first review on occurrence and distribution of pharmaceuticals and personal care products (PPCPs) is presented. The literature survey conducted here was initiated by the current Assessment of the Arctic Monitoring and Assessment Programme (AMAP). This first review on the occurrence and environmental profile of PPCPs in the Arctic identified the presence of 110 related substances in the Arctic environment based on the reports from scientific publications, national and regional assessments and surveys, as well as academic research studies (i...
July 31, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28760747/significant-synteny-and-co-localization-of-ecologically-relevant-quantitative-trait-loci-within-and-across-species-of-salmonid-fishes
#20
Arne Jacobs, Robyn Womack, Mel Chen, Karim Gharbi, Kathryn Elmer
The organization of functional regions within genomes has important implications for evolutionary potential. Considerable research effort has gone toward identifying the genomic basis of phenotypic traits of interest through quantitative trait loci (QTL) analyses. Less research has assessed the arrangement of QTL in the genome within and across species. To investigate the distribution, extent of co-localization, and the synteny of QTL for ecologically relevant traits, we used a comparative genomic mapping approach within and across a range of salmonid species...
July 31, 2017: Genetics
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