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https://www.readbyqxmd.com/read/28651333/responses-of-lichen-communities-to-18%C3%A2-years-of-natural-and-experimental-warming
#1
Juha M Alatalo, Annika K Jägerbrand, Shengbin Chen, Ulf Molau
Background and Aims: Climate change is expected to have major impacts on high alpine and arctic ecosystems in the future, but empirical data on the impact of long-term warming on lichen diversity and richness are sparse. This study report the effects of 18 years of ambient and experimental warming on lichens and vascular plant cover in two alpine plant communities, a dry heath with sparse canopy cover (54 %) and a mesic meadow with a more developed (67 %) canopy cover, in sub-arctic Sweden...
June 22, 2017: Annals of Botany
https://www.readbyqxmd.com/read/28651318/fate-of-polycyclic-aromatic-hydrocarbons-from-the-north-pacific-to-the-arctic-field-measurements-and-fugacity-model-simulation
#2
Hongwei Ke, Mian Chen, Mengyang Liu, Meng Chen, Mengshan Duan, Peng Huang, Jiajun Hong, Yan Lin, Shayen Cheng, Xuran Wang, Mengxue Huang, Minggang Cai
Polycyclic aromatic hydrocarbons (PAHs) have accumulated ubiquitously inArctic environments, where re-volatilization of certain organic pollutants as a result of climate change has been observed. To investigate the fate of semivolatile organic compounds in the Arctic, dissolved PAHs in the surface seawaters from the temperate Pacific Ocean to the Arctic Ocean, as well as a water column in the Arctic Ocean, were collected during the 4th Chinese National Arctic Research Expedition in summer 2010. The total concentrations of seven dissolved PAHs in surface water ranged from 1...
June 16, 2017: Chemosphere
https://www.readbyqxmd.com/read/28650623/spatial-distributions-of-ddts-in-the-water-masses-of-the-arctic-ocean
#3
Daniel Carrizo, Anna Sobek, Joan A Salvadó, Örjan Gustafsson
There is a scarcity of data on the amount and distribution of the organochlorine pesticide dichlorodiphenyltrichloroethane (DDT) and its metabolites in intermediate and deep ocean water masses. Here, the distribution and inventories of DDTs in water of the Arctic shelf seas and the interior basin are presented. The occurrence of ∑6DDT (0.10 to 66 pg L-1) in the surface water was dominated by 4, 4'-DDE. In the Central Arctic Ocean increasing concentrations of DDE with depth were observed in the Makarov and Amundsen basins...
June 26, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28649681/bio-inspired-colorful-flexible-defrostable-light-scattering-hybrid-films-for-the-effective-distribution-of-led-light
#4
Seongpil An, Hong Seok Jo, Yong Il Kim, Kyo Yong Song, Min-Woo Kim, Kyu Bum Lee, Alexander L Yarin, Sam S Yoon
Bioluminescent jellyfish has a unique structure derived from fiber/polymer interfaces that is advantageous for effective light scattering in the dark, deep sea water. Herein, we demonstrate the fabrication of bio-inspired hybrid films by mimicry of the jellyfish's structure, leading to excellent light-scattering performance and defrosting capability. A haze value reaching 59.3% and a heating temperature of up to 292 °C were achieved with the films. Accordingly, the developed surface constitutes an attractive optical device for lighting applications, especially for street or vehicle luminaries for freezing Arctic-climate countries...
June 26, 2017: Nanoscale
https://www.readbyqxmd.com/read/28649233/microbial-community-response-to-terrestrially-derived-dissolved-organic-matter-in-the-coastal-arctic
#5
Rachel E Sipler, Colleen T E Kellogg, Tara L Connelly, Quinn N Roberts, Patricia L Yager, Deborah A Bronk
Warming at nearly twice the global rate, higher than average air temperatures are the new 'normal' for Arctic ecosystems. This rise in temperature has triggered hydrological and geochemical changes that increasingly release carbon-rich water into the coastal ocean via increased riverine discharge, coastal erosion, and the thawing of the semi-permanent permafrost ubiquitous in the region. To determine the biogeochemical impacts of terrestrially derived dissolved organic matter (tDOM) on marine ecosystems we compared the nutrient stocks and bacterial communities present under ice-covered and ice-free conditions, assessed the lability of Arctic tDOM to coastal microbial communities from the Chukchi Sea, and identified bacterial taxa that respond to rapid increases in tDOM...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28647153/organic-matter-properties-of-fennoscandian-ecosystems-potential-oxidation-of-northern-environments-under-future-change
#6
Gareth D Clay, Fred Worrall, Rebecca Plummer, Catherine S Moody
The oxidative ratio (OR) of an ecosystem, which reflects the ratio of O2:CO2 associated with ecosystem gas exchanges, is an important parameter in understanding the sink of CO2 represented by the terrestrial biosphere. There is a growing body of ecosystem-based approaches to understand OR; however, there are still a number of unknowns. This study addressed two gaps in our understanding of the oxidation of the terrestrial biosphere: (1) What is the oxidation state of Arctic ecosystems, and in particular permafrost soils? (2) Will coupled climate and land use change cause the terrestrial organic matter oxidation state to change? The study considered eight locations along a transect from southern Sweden to northern Norway and sampled different organic matter types (soil, litter, trees, and herbaceous vegetation) as well as different soil orders (Inceptisols, Spodosols, Histosols, and Gelisols)...
June 21, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28646231/inter-annual-variability-of-transparent-exopolymer-particles-in-the-arctic-ocean-reveals-high-sensitivity-to-ecosystem-changes
#7
Anja Engel, Judith Piontek, Katja Metfies, Sonja Endres, Pim Sprong, Ilka Peeken, Steffi Gäbler-Schwarz, Eva-Maria Nöthig
Transparent exopolymer particles (TEP) are a class of marine gel particles and important links between surface ocean biology and atmospheric processes. Derived from marine microorganisms, these particles can facilitate the biological pumping of carbon dioxide to the deep sea, or act as cloud condensation and ice nucleation particles in the atmosphere. Yet, environmental controls on TEP abundance in the ocean are poorly known. Here, we investigated some of these controls during the first multiyear time-series on TEP abundance for the Fram Strait, the Atlantic gateway to the Central Arctic Ocean...
June 23, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28643454/polar-zoobenthos-blue-carbon-storage-increases-with-sea-ice-losses-because-across-shelf-growth-gains-from-longer-algal-blooms-outweigh-ice-scour-mortality-in-the-shallows
#8
David K A Barnes
One of the major climate-forced global changes has been white to blue to green; losses of sea ice extent in time and space around Arctic and West Antarctic seas has increased open water and the duration (though not magnitude) of phytoplankton blooms. Blueing of the poles has increases potential for heat absorption for positive feedback but conversely the longer phytoplankton blooms have increased carbon export to storage and sequestration by shelf benthos. However, ice shelf collapses and glacier retreat can calve more icebergs, and the increased open water allows icebergs more opportunities to scour the seabed, reducing zoobenthic blue carbon capture and storage...
June 23, 2017: Global Change Biology
https://www.readbyqxmd.com/read/28641603/molecular-detection-of-sarcocystis-lutrae-in-the-european-badger-meles-meles-in-scotland
#9
T Lepore, P M Bartley, F Chianini, A I Macrae, E A Innes, F Katzer
Neck samples from 54 badgers and 32 tongue samples of the same badgers (Meles meles), collected in the Lothians and Borders regions of Scotland, were tested using polymerase chain reactions (PCRs) directed against the 18S ribosomal DNA and the internal transcribed spacer (ITS1) region of protozoan parasites of the family Sarcocystidae. Positive results were obtained from 36/54 (67%) neck and 24/32 (75%) tongue samples using an 18S rDNA PCR. A 468 base pair consensus sequence that was generated from the 18S rDNA PCR amplicons (KX229728) showed 100% identity to Sarcocystis lutrae...
June 23, 2017: Parasitology
https://www.readbyqxmd.com/read/28640885/phylogeography-of-a-tough-rock-survivor-in-european-dry-grasslands
#10
Daniela Listl, Peter Poschlod, Christoph Reisch
Phylogeographic analyses of plants in Europe have revealed common glacial refugia and migration routes for several trees and herbs with arctic-alpine distributions. The postglacial histories of dry grassland species in central Europe have rarely been analyzed, even though the extremely species-rich habitat is threatened. Sedum album (Crassulaceae) is a common inhabitant of rocky sites in central European dry grasslands. We inferred the phylogeographic history of S. album over its distribution range in Europe...
2017: PloS One
https://www.readbyqxmd.com/read/28639616/current-rates-and-mechanisms-of-subsea-permafrost-degradation-in-the-east-siberian-arctic-shelf
#11
Natalia Shakhova, Igor Semiletov, Orjan Gustafsson, Valentin Sergienko, Leopold Lobkovsky, Oleg Dudarev, Vladimir Tumskoy, Michael Grigoriev, Alexey Mazurov, Anatoly Salyuk, Roman Ananiev, Andrey Koshurnikov, Denis Kosmach, Alexander Charkin, Nicolay Dmitrevsky, Victor Karnaukh, Alexey Gunar, Alexander Meluzov, Denis Chernykh
The rates of subsea permafrost degradation and occurrence of gas-migration pathways are key factors controlling the East Siberian Arctic Shelf (ESAS) methane (CH4) emissions, yet these factors still require assessment. It is thought that after inundation, permafrost-degradation rates would decrease over time and submerged thaw-lake taliks would freeze; therefore, no CH4 release would occur for millennia. Here we present results of the first comprehensive scientific re-drilling to show that subsea permafrost in the near-shore zone of the ESAS has a downward movement of the ice-bonded permafrost table of ∼14 cm year(-1) over the past 31-32 years...
June 22, 2017: Nature Communications
https://www.readbyqxmd.com/read/28633515/crystal-structure-and-functional-characterization-of-a-cytochrome-p450-bacyp106a2-from-bacillus-sp-pamc-23377
#12
Ki-Hwa Kim, Chang Woo Lee, Bikash Dangi, Sun-Ha Park, Hyun Park, Tae-Jin Oh, Jun Hyuck Lee
Bacterial cytochrome P450 (CYP) steroid hydroxylases are effectively useful in the pharmaceutical industry for introducing hydroxyl groups to a wide range of steroids. We found a putative CYP steroid hydroxylase (BaCYP106A2) from the bacterium Bacillus sp. PAMC 23377 isolated from Kara Sea of the Arctic Ocean, showing 94% sequence similarity with BmCYP106A2 (Bacillus megaterium ATCC 13368). In this study, soluble BaCYP106A2 was overexpressed to evaluate its substrate-binding activity. The substrate affinity (Kd value) to 4-androstenedione was 387 ± 37 µM...
June 21, 2017: Journal of Microbiology and Biotechnology
https://www.readbyqxmd.com/read/28631732/skillful-prediction-of-northern-climate-provided-by-the-ocean
#13
Marius Årthun, Tor Eldevik, Ellen Viste, Helge Drange, Tore Furevik, Helen L Johnson, Noel S Keenlyside
It is commonly understood that a potential for skillful climate prediction resides in the ocean. It nevertheless remains unresolved to what extent variable ocean heat is imprinted on the atmosphere to realize its predictive potential over land. Here we assess from observations whether anomalous heat in the Gulf Stream's northern extension provides predictability of northwestern European and Arctic climate. We show that variations in ocean temperature in the high latitude North Atlantic and Nordic Seas are reflected in the climate of northwestern Europe and in winter Arctic sea ice extent...
June 20, 2017: Nature Communications
https://www.readbyqxmd.com/read/28631303/photophobia-and-seasonal-variation-of-migraine-in-a-subarctic-population
#14
Svein I Bekkelund, Kai I Müller, Aleksander Wilhelmsen, Karl B Alstadhaug
OBJECTIVE: To investigate associations between photophobia and seasonal variation of migraine. METHODS: In this cross-sectional study, migraineurs consecutively recruited were referred to a specialist center located above the Arctic Circle at 68-71 degrees North during a 2.5-year period. Data were obtained through a structured interview. RESULTS: In total, 302 migraineurs with a mean (±SD) age of 35.5 (±12.6) years were included. Patients who reported seasonal variation of migraine (n = 90; 29...
June 19, 2017: Headache
https://www.readbyqxmd.com/read/28630446/strong-sub-seasonal-wintertime-cooling-over-east-asia-and-northern-europe-associated-with-super-el-ni%C3%A3-o-events
#15
Xin Geng, Wenjun Zhang, Malte F Stuecker, Fei-Fei Jin
East Asia experienced a record-breaking cold event during the 2015/16 boreal winter, with pronounced impacts on livelihood in the region. We find that this large-scale cold spell can be attributed to the concurrent super El Niño event in the tropical Pacific. Our analysis reveals that all super El Niño winters (1982/83, 1997/98, and 2015/16) were accompanied by a rapid sub-seasonal North Atlantic Oscillation (NAO)/Arctic Oscillation (AO) phase reversal from a positive to a negative state during early January, which was largely caused by the interaction of these super El Niño events with the subtropical jet annual cycle...
June 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28630224/successful-conservative-treatment-of-severe-frostbite-lesions-in-a-greenlandic-inuit
#16
Martin Ekdahl, Luit Penninga
Frostbite may cause lesions. The severity ranges from superficial wounds to severe cases with loss of limbs and tissue. Hence, proper treatment is of utmost importance. We present a case of an 18-year-old man from Arctic Greenland who was admitted with severe frostbite lesions involving both hands. The patient had fallen asleep outside during extreme temperatures. He was treated conservatively with proper wound care, antibiotics and intensive physical therapy. The patient made a full recovery without sequelae...
June 19, 2017: BMJ Case Reports
https://www.readbyqxmd.com/read/28629143/nutrients-and-other-environmental-factors-influence-virus-abundances-across-oxic-and-hypoxic-marine-environments
#17
Jan F Finke, Brian P V Hunt, Christian Winter, Eddy C Carmack, Curtis A Suttle
Virus particles are highly abundant in seawater and, on average, outnumber microbial cells approximately 10-fold at the surface and 16-fold in deeper waters; yet, this relationship varies across environments. Here, we examine the influence of a suite of environmental variables, including nutrient concentrations, salinity and temperature, on the relationship between the abundances of viruses and prokaryotes over a broad range of spatial and temporal scales, including along a track from the Northwest Atlantic to the Northeast Pacific via the Arctic Ocean, and in the coastal waters of British Columbia, Canada...
June 17, 2017: Viruses
https://www.readbyqxmd.com/read/28628003/clinical-effectiveness-and-cost-effectiveness-results-from-the-randomised-phase-iib-trial-in-previously-untreated-patients-with-chronic-lymphocytic-leukaemia-to-compare-fludarabine-cyclophosphamide-and-rituximab-with-fludarabine-cyclophosphamide-mitoxantrone
#18
Dena R Howard, Talha Munir, Lucy McParland, Andy C Rawstron, Anna Chalmers, Walter M Gregory, John L O'Dwyer, Alison Smith, Roberta Longo, Abraham Varghese, Alexandra Smith, Peter Hillmen
BACKGROUND: The conventional frontline therapy for fit patients with chronic lymphocytic leukaemia (CLL) is fludarabine, cyclophosphamide and rituximab (FCR). Rituximab (Mabthera(®), Roche Products Ltd) targets the CD20 antigen, which is expressed at low levels in CLL. The standard dose of rituximab in CLL (375 mg/m(2) in cycle 1 and 500 mg/m(2) in cycles 2-6) was selected based on toxicity data only. Small doses of rituximab (as low as 20 mg) have biological activity in CLL, with an immediate reduction in circulating CLL cells and down-regulation of CD20...
May 2017: Health Technology Assessment: HTA
https://www.readbyqxmd.com/read/28624116/variability-in-magnesium-content-in-arctic-echinoderm-skeletons
#19
A Iglikowska, J Najorka, A Voronkov, M Chełchowski, P Kukliński
In this study, 235 measurements of magnesium concentration in echinoderm's skeletons were compiled, including 30 species and 216 specimens collected from northern and western Barents Sea. We aimed to reveal the scale of Mg variation in the skeletons of Arctic echinoderms. Furthermore, we attempted to examine whether the Mg concentration in echinoderm skeletons is determined primarily by biological factors or is a passive result of environmental influences. We found that the Mg concentration in echinoderm skeletons was characteristic for particular echinoderm classes or was even species-specific...
June 6, 2017: Marine Environmental Research
https://www.readbyqxmd.com/read/28623226/entraining-to-the-polar-day-circadian-rhythms-in-arctic-ground-squirrels
#20
Cory T Williams, Brian M Barnes, Lily Yan, C Loren Buck
Circadian systems are principally entrained to 24h light/dark cycles, but this cue is seasonally absent in polar environments. Although some resident polar vertebrates have weak circadian clocks and are seasonally arrhythmic, the arctic ground squirrel (AGS) maintains daily rhythms of physiology and behavior throughout the summer, which includes six weeks of constant daylight. Here, we show that persistent daily rhythms in AGS are maintained through a circadian system that readily entrains to the polar day yet remains insensitive to entrainment by rapid light-dark transitions, which AGS generate naturally due to their semi-fossorial behavior...
June 16, 2017: Journal of Experimental Biology
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