Read by QxMD icon Read


Scott N Williamson, Faron S Anslow, Garry K C Clarke, John A Gamon, Alexander H Jarosch, David S Hik
Decreasing spring snow cover may amplify Arctic warming through the snow albedo feedback. To examine the impact of snowmelt on increasing temperature we used a 5,000 m elevation gradient in Yukon, Canada, extending from valley-bottom conifer forests, through middle elevation tundra, to high elevation icefields, to compare validated downscaled reanalysis air temperature patterns across elevational bands characterized by different patterns of spring snowmelt. From 2000 to 2014 we observed surface warming of 0...
June 13, 2018: Scientific Reports
Ken D Tape, Benjamin M Jones, Christopher D Arp, Ingmar Nitze, Guido Grosse
Increasing air temperatures are changing the arctic tundra biome. Permafrost is thawing, snow duration is decreasing, shrub vegetation is proliferating, and boreal wildlife is encroaching. Here we present evidence of the recent range expansion of North American beaver (Castor canadensis) into the Arctic, and consider how this ecosystem engineer might reshape the landscape, biodiversity, and ecosystem processes. We developed a remote sensing approach that maps formation and disappearance of ponds associated with beaver activity...
May 30, 2018: Global Change Biology
Junyi Liang, Jiangyang Xia, Zheng Shi, Lifen Jiang, Shuang Ma, Xingjie Lu, Marguerite Mauritz, Susan M Natali, Elaine Pegoraro, C Ryan Penton, César Plaza, Verity G Salmon, Gerardo Celis, James R Cole, Konstantinos T Konstantinidis, James M Tiedje, Jizhong Zhou, Edward A G Schuur, Yiqi Luo
Climate warming can result in both abiotic (e.g., permafrost thaw) and biotic (e.g., microbial functional genes) changes in Arctic tundra. Recent research has incorporated dynamic permafrost thaw in Earth system models (ESMs) and indicates that Arctic tundra could be a significant future carbon (C) source due to the enhanced decomposition of thawed deep soil C. However, warming-induced biotic changes may influence biologically related parameters and the consequent projections in ESMs. How model parameters associated with biotic responses will change under warming and to what extent these changes affect projected C budgets have not been carefully examined...
May 26, 2018: Global Change Biology
E S Ivanova, N E Dokuchaev, S E Spiridonov
Antechiniella septentrionalis n. sp. (Spirurida: Acuariidae) is described from the duodenum of a tundra vole, Microtus oeconomus (Pallas), collected in the Magadan region in the north-east part of Russia. It differs from A. suffodiax (Beveridge & Barker, 1975) and A. sertatum Smales, 1991 mainly in having a larger number of postcloacal papillae (5-6 pairs vs 4 pairs), a differently shaped left spicule, the disposition of precloacal papillae in two rows vs one, and oblong vs oval eggs. Other differences include the different disposition of ovaries in A...
May 15, 2018: Journal of Helminthology
Aaron M Jubb, Jeremy R Eskelsen, Xiangping Yin, Jianqiu Zheng, Michael J Philben, Eric M Pierce, David E Graham, Stan D Wullschleger, Baohua Gu
Massive amounts of organic carbon have accumulated in Arctic permafrost and soils due to anoxic and low temperature conditions that limit aerobic microbial respiration. Alternative electron acceptors are thus required for microbes to degrade organic carbon in these soils. Iron or iron oxides have been recognized to play an important role in carbon cycle processes in Arctic soils, although the exact form and role as an electron acceptor or donor remain poorly understood. Here, Arctic biofilms collected during the summers of 2016 and 2017 from tundra surface waters on the Seward Peninsula of western Alaska were characterized with a suite of microscopic and spectroscopic methods...
August 15, 2018: Science of the Total Environment
Roman Vasilevich, Evgeny Lodygin, Vasily Beznosikov, Evgeny Abakumov
Humic substances (HSs) from the mire peat soils of the forest-tundra zone of the European northeast part of Russia have been characterized in terms of molecular composition. This was accomplished using solid-state 13 C nuclear magnetic resonance (13 C NMR) techniques and electron spin resonance (ESR) spectroscopy. The composition depended on the intensity of cryogenic processes in the active layer, the quality of the humification precursors (the degree of peat material transformation), and the biochemical selection of aromatic fragments during humification...
February 15, 2018: Science of the Total Environment
Xiaolong Wang, Wei Zhao, Lin Li, Jian You, Biao Ni, Xia Chen
Four small oval populations and five large intensive populations of Rhododendron aureum growing at the alpine in Changbai Mountain (China) were studied in two types of habitat (in the tundra and in Betula ermanii forest). Identification and delimitation of genets were inferred from excavation in small populations and from amplified fragment length polymorphism (AFLP) markers by the standardized sampling design in large populations. Clonal architecture and clonal diversity were then estimated. For the four small populations, they were monoclonal, the spacer length (18...
2018: PloS One
Sarah Susanne Übleis, Claudia Cuk, Michaela Nawratil, Julia Butter, Ellen Schoener, Adelheid G Obwaller, Thomas Zechmeister, Georg G Duscher, Franz Rubel, Karin Lebl, Carina Zittra, Hans-Peter Fuehrer
Information on mosquito-borne filarioid helminths in Austria is scarce, but recent discoveries of Dirofilaria repens indicate autochthonous distribution of this parasite in Eastern Austria. In the current xenomonitoring study, more than 48,000 mosquitoes were collected in Eastern Austria between 2013 and 2015, using different sampling techniques and storage conditions, and were analysed in pools with molecular tools for the presence of filarioid helminth DNA. Overall, DNA of D. repens , Setaria tundra , and two unknown filarioid helminths were documented in twenty mosquito pools within the mitochondrial cox1 gene (barcode region)...
2018: Canadian Journal of Infectious Diseases & Medical Microbiology
Sanjay K S Patel, Virendra Kumar, Primata Mardina, Jinglin Li, Rowina Lestari, Vipin C Kalia, Jung-Kul Lee
In the present study, co-cultures of the methanotrophs Methylocella tundrae, Methyloferula stellata, and Methylomonas methanica were evaluated for improving methanol production with their application. Among the different combinations, the co-culture of M. tundrae and M. methanica increased methanol production to 4.87 mM using methane (CH4 ) as feed. When simulated biogas mixtures were used as feed, the maximum methanol production was improved to 8.66, 8.45, and 9.65 mM by free and encapsulated co-cultures in 2% alginate and silica-gel, respectively...
April 25, 2018: Bioresource Technology
Jennifer C McElwain
Human carbon use during the next century will lead to atmospheric carbon dioxide concentrations (pCO2 ) that have been unprecedented for the past 50-100+ million years according to fossil plant-based CO2 estimates. The paleobotanical record of plants offers key insights into vegetation responses to past global change, including suitable analogs for Earth's climatic future. Past global warming events have resulted in transient poleward migration at rates that are equivalent to the lowest climate velocities required for current taxa to keep pace with climate change...
April 29, 2018: Annual Review of Plant Biology
Colin M McGill, Patrick L Tomco, Regina M Ondrasik, Kaitlyn C Belknap, Gaelen K Dwyer, Daniel J Quinlan, Thomas A Kircher, Cheryl P Andam, Timothy J Brown, David F Claxton, Brian M Barth
Acute myeloid leukemia (AML) is an aggressive hematological malignancy that is one of the more common pediatric malignancies in addition to occurring with high incidence in the aging population. Unfortunately, these patient groups are quite sensitive to toxicity from chemotherapy. Northern Labrador tea, or Rhododendron tomentosum Harmaja (a.k.a. Ledum palustre subsp. decumbens) or "tundra tea," is a noteworthy medicinal plant used by indigenous peoples in Alaska, Canada, and Greenland to treat a diversity of ailments...
April 27, 2018: Phytotherapy Research: PTR
Francesco Boscutti, Valentino Casolo, Paola Beraldo, Enrico Braidot, Marco Zancani, Christian Rixen
Enhanced shrub growth and expansion are widespread responses to climate warming in many arctic and alpine ecosystems. Warmer temperatures and shrub expansion could cause major changes in plant community structure, affecting both species composition and diversity. To improve our understanding of the ongoing changes in plant communities in alpine tundra, we studied interrelations among climate, shrub growth, shrub cover and plant diversity, using an elevation gradient as a proxy for climate conditions. Specifically, we analyzed growth of bilberry (Vaccinium myrtillus L...
2018: PloS One
Nicholas C Parazoo, Almut Arneth, Thomas A M Pugh, Ben Smith, Nicholas Steiner, Kristina Luus, Roisin Commane, Josh Benmergui, Eric Stofferahn, Junjie Liu, Christian Rödenbeck, Randy Kawa, Eugenie Euskirchen, Donatella Zona, Kyle Arndt, Walt Oechel, Charles Miller
The springtime transition to regional-scale onset of photosynthesis and net ecosystem carbon uptake in boreal and tundra ecosystems are linked to the soil freeze-thaw state. We present evidence from diagnostic and inversion models constrained by satellite fluorescence and airborne CO2 from 2012 to 2014 indicating the timing and magnitude of spring carbon uptake in Alaska correlates with landscape thaw and ecoregion. Landscape thaw in boreal forests typically occurs in late April (DOY 111 ± 7) with a 29 ± 6 day lag until photosynthetic onset...
April 24, 2018: Global Change Biology
Jessica L Schedlbauer, Ned Fetcher, Katherine Hood, Michael L Moody, Jianwu Tang
Ecotypic differentiation in the tussock-forming sedge Eriophorum vaginatum has led to the development of populations that are locally adapted to climate in Alaska's moist tussock tundra. As a foundation species, E. vaginatum plays a central role in providing topographic and microclimatic variation essential to these ecosystems, but a changing climate could diminish the importance of this species. As Arctic temperatures have increased, there is evidence of adaptational lag in E. vaginatum , as locally adapted ecotypes now exhibit reduced population growth rates...
April 2018: Ecology and Evolution
Chun-Gon Kim, Jong-Pyo Kang, Yue Huo, Mohan Chokkalingam, Yeon-Ju Kim, Dong-Hyun Kim, Deok-Chun Yang
A novel bacterium, designated DCY114T , was isolated from ginseng-cultivated soil in Gochang-gun, Republic of Korea. This isolate was assigned to the genus Paenibacillus and is closely related to Paenibacillus amylolyticus NRRL NRS-290T (98.3%), P. dongdonensis KUDC0114T (98.0%), P. tylopili MK2T (97.9%), P. tundrae A10bT (97.8%), and P. xylanexedens B22aT (97.5%) based on 16S rRNA gene sequence analysis. Strain DCY114T is a Gram-reaction positive, catalase and oxidase positive, facultatively aerobic rod that is motile by peritrichous flagella...
April 20, 2018: Archives of Microbiology
Véronique Forbes, Derek Sikes
This paper presents the results of a survey of beetles conducted in the vicinity of the archaeological site of Nunalleq, a pre-contact (16th -17th century AD) indigenous forager settlement located near the modern Yup'ik village of Quinhagak, in the Yukon-Kuskokwim delta, southwestern Alaska. Records and habitat data are reported for 74 beetle taxa collected in tundra, riparian, aquatic and anthropogenic environments from a region of Alaska that has been poorly studied by entomologists. This includes the first mainland Alaskan record for the byrrhid Simplocaria metallica (Sturm)...
2018: Biodiversity Data Journal
Hongmei Chen, Ziming Yang, Rosalie K Chu, Nikola Tolic, Liyuan Liang, David E Graham, Stan D Wullschleger, Baohua Gu
Molecular composition of the Arctic soil organic carbon (SOC) and its susceptibility to microbial degradation are uncertain due to heterogeneity and unknown SOC compositions. Using ultrahigh-resolution mass spectrometry, we determined the susceptibility and compositional changes of extractable dissolved organic matter (EDOM) in an anoxic warming incubation experiment (up to 122 days) with a tundra soil from Alaska (United States). EDOM was extracted with 10 mM NH4 HCO3 from both the organic- and mineral-layer soils during incubation at both -2 and 8 °C...
April 17, 2018: Environmental Science & Technology
Claire C Treat, A Anthony Bloom, Maija E Marushchak
Wetlands are the single largest natural source of atmospheric methane (CH4 ), a greenhouse gas, and occur extensively in the northern hemisphere. Large discrepancies remain between "bottom-up" and "top-down" estimates of northern CH4 emissions. To explore whether these discrepancies are due to poor representation of nongrowing season CH4 emissions, we synthesized nongrowing season and annual CH4 flux measurements from temperate, boreal, and tundra wetlands and uplands. Median nongrowing season wetland emissions ranged from 0...
March 22, 2018: Global Change Biology
Mark A Lee
Forage plants are valuable because they maintain wild and domesticated herbivores, and sustain the delivery of meat, milk and other commodities. Forage plants contain different quantities of fibre, lignin, minerals and protein, and vary in the proportion of their tissue that can be digested by herbivores. These nutritive components are important determinants of consumer growth rates, reproductive success and behaviour. A dataset was compiled to quantify variation in forage plant nutritive values within- and between-plant species, and to assess variation between plant functional groups and bioclimatic zones...
March 17, 2018: Journal of Plant Research
Xue-Yan Liu, Keisuke Koba, Lina A Koyama, Sarah E Hobbie, Marissa S Weiss, Yoshiyuki Inagaki, Gaius R Shaver, Anne E Giblin, Satoru Hobara, Knute J Nadelhoffer, Martin Sommerkorn, Edward B Rastetter, George W Kling, James A Laundre, Yuriko Yano, Akiko Makabe, Midori Yano, Cong-Qiang Liu
Plant nitrogen (N) use is a key component of the N cycle in terrestrial ecosystems. The supply of N to plants affects community species composition and ecosystem processes such as photosynthesis and carbon (C) accumulation. However, the availabilities and relative importance of different N forms to plants are not well understood. While nitrate (NO3 - ) is a major N form used by plants worldwide, it is discounted as a N source for Arctic tundra plants because of extremely low NO3 - concentrations in Arctic tundra soils, undetectable soil nitrification, and plant-tissue NO3 - that is typically below detection limits...
March 27, 2018: Proceedings of the National Academy of Sciences of the United States of America
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"