scholarly journals Polar Cryoconite Associated Microbiota Is Dominated by Hemispheric Specialist Genera

2021 ◽  
Vol 12 ◽  
Author(s):  
Jasmin L. Millar ◽  
Elizabeth A. Bagshaw ◽  
Arwyn Edwards ◽  
Ewa A. Poniecka ◽  
Anne D. Jungblut
Keyword(s):  
18S Rrna Gene ◽  
The Arctic ◽  
Rrna Gene ◽  
Sequence Variant ◽  
Polar Regions ◽  
Core Group ◽  
Wide Range ◽  
The Family ◽  
Rrna Gene Sequencing ◽  
The Antarctic

Cryoconite holes, supraglacial depressions containing water and microbe-mineral aggregates, are known to be hotspots of microbial diversity on glacial surfaces. Cryoconite holes form in a variety of locations and conditions, which impacts both their structure and the community that inhabits them. Using high-throughput 16S and 18S rRNA gene sequencing, we have investigated the communities of a wide range of cryoconite holes from 15 locations across the Arctic and Antarctic. Around 24 bacterial and 11 eukaryotic first-rank phyla were observed in total. The various biotic niches (grazer, predator, photoautotroph, and chemotroph), are filled in every location. Significantly, there is a clear divide between the bacterial and microalgal communities of the Arctic and that of the Antarctic. We were able to determine the groups contributing to this difference and the family and genus level. Both polar regions contain a “core group” of bacteria that are present in the majority of cryoconite holes and each contribute >1% of total amplicon sequence variant (ASV) abundance. Whilst both groups contain Microbacteriaceae, the remaining members are specific to the core group of each polar region. Additionally, the microalgal communities of Arctic cryoconite holes are dominated by Chlamydomonas whereas the Antarctic cryoconite holes are dominated by Pleurastrum. Therefore cryoconite holes may be a global feature of glacier landscapes, but they are inhabited by regionally distinct microbial communities. Our results are consistent with the notion that cryoconite microbiomes are adapted to differing conditions within the cryosphere.

Governing the antipodes: international cooperation in Antarctica and the Arctic

Polar Record ◽  
2015 ◽  
Vol 52 (2) ◽  
pp. 230-238 ◽  
Author(s):  
Oran R. Young
Keyword(s):  
Effective Means ◽  
The Arctic ◽  
Polar Regions ◽  
Military Operations ◽  
Arctic Council ◽  
Governance Systems ◽  
Wide Range ◽  
The Face ◽  
Antarctic Treaty ◽  
The Antarctic

ABSTRACTThe Arctic and the Antarctic appear to be polar opposites with regard to many matters, including the systems of governance that have evolved in the two regions. Antarctica is demilitarised, closed to economic development, open to a wide range of scientific activities, and subject to strict environmental regulations under the terms of the legally binding Antarctic Treaty of 1959 along with several supplementary measures that together form the Antarctic Treaty System (ATS). The Arctic, by contrast, is a theatre of military operations, a site of largescale industrial activities, a homeland for sizable groups of indigenous peoples, and a focus of growing concern regarding the environmental impacts of human activities. The Arctic Council, the principal international body concerned with governance at the regional level, operates under the terms of a ministerial declaration that is not legally binding; it lacks the authority to make formal decisions about matters of current interest. Digging a little deeper, however, one turns up some illuminating similarities between the governance systems operating in the antipodes. In this article, I pursue this line of thinking, setting forth a range of observations relating to (i) the history of governance in the antipodes, (ii) institutional innovations occurring in these regions, (iii) issues of membership, (iv) jurisdictional concerns, (v) the role of science, (vi) relations with the UN system, (vii) institutional interplay, and (viii) the adaptiveness of governance systems in the face of changing circumstances. The governance systems for the polar regions are not likely to converge anytime soon. Nevertheless, this analysis should be of interest not only to those concerned with the fate of Antarctica and the Arctic but also to those seeking to find effective means of addressing needs for governance in other settings calling for governance without government.

scholarly journals Uncertainties and assessments of chemistry-climate models of the stratosphere

2002 ◽  
Vol 2 (4) ◽  
pp. 1035-1096 ◽  
Author(s):  
J. Austin ◽  
D. Shindell ◽  
S. R. Beagley ◽  
C. Brühl ◽  
M. Dameris ◽  
...  
Keyword(s):  
Climate Models ◽  
Wave Drag ◽  
Horizontal Resolution ◽  
The Arctic ◽  
Cold Bias ◽  
Polar Regions ◽  
Wide Range ◽  
Antarctic Ozone ◽  
Stratospheric Clouds ◽  
The Antarctic

Abstract. In recent years a number of chemistry-climate models have been developed with an emphasis on the stratosphere. Such models cover a wide range of timescales of integration and vary considerably in complexity. The results of specific diagnostics are here analysed to examine the differences amongst individual models and observations, to assess the consistency of model predictions, with a particular focus on polar ozone. For example, many models indicate a significant cold bias in high latitudes, the 'cold pole problem', particularly in the southern hemisphere during winter and spring. This is related to wave propagation from the troposphere which can be improved by improving model horizontal resolution and with the use of non-orographic gravity wave drag. As a result of the widely differing modeled polar temperatures, different amounts of polar stratospheric clouds are simulated which in turn result in varying ozone values in the models. The results are also compared to determine the possible future behaviour of ozone, with an emphasis on the polar regions and mid-latitudes. All models predict eventual ozone recovery, but give a range of results concerning its timing and extent. Differences in the simulation of gravity waves and planetary waves as well as model resolution are likely major sources of uncertainty for this issue. In the Antarctic, the ozone hole has probably reached almost its deepest although the vertical and horizontal extent of depletion may increase slightly further over the next few years. According to the model results, Antarctic ozone recovery could begin any year within the range 2001 to 2008. For the Arctic, most models indicate that small ozone losses may continue for a few more years and that recovery could begin any year within the range 2004 to 2019. The start of ozone recovery in the Arctic is therefore expected to appear later than in the Antarctic in most models. Further, interannual variability will tend to mask the signal for longer in the Arctic than in the Antarctic, delaying still further the date at which ozone recovery may be said to have started. In the longer term, the model results suggest that full recovery of ozone to 1980 levels is not expected in the Antarctic until about the year 2050. Earlier recovery to 1980 levels may be possible in the Arctic, but model differences are too large compared with the simulated changes to obtain a reliable date.

Overwintering strategies of Antarctic organisms

2000 ◽  
Vol 8 (1) ◽  
pp. 1-19 ◽  
Author(s):  
Charles S Cockell ◽  
M Dale Stokes ◽  
Keith E Korsmeyer
Keyword(s):  
Phenotypic Plasticity ◽  
Avoidance Behavior ◽  
The Arctic ◽  
Polar Regions ◽  
Physiological Changes ◽  
Fat Storage ◽  
Winter Conditions ◽  
Wide Range ◽  
The Antarctic ◽  
Extremes Of Temperature

The extremity of winter conditions in the present-day polar regions is unique on Earth. Each year organisms are subjected to extremes of temperature and depending on latitude, prolonged periods of darkness. Organisms have adapted to these extremes through a variety of overwintering strategies that range from physiological changes to alterations in geographical distributions. Some adaptations are specific to just a few taxa, such as huddling by penguins, a strategy that is also seen in some Arctic mammals. However, other strategies are common to a wide diversity of taxa, such as fat storage throughout the winter or migratory avoidance behavior. Although many organisms have specifically adapted to polar conditions, it is also apparent that for many, survival of the Antarctic winter draws upon an inherent phenotypic plasticity particularly amongst the invertebrates. In this review the adaptations of a wide range of organisms to the polar winter environment are discussed. This review concentrates on the Antarctic, although the Arctic is discussed for comparison where appropriate.Keywords: winter, overwintering, polar, Arctic, Antarctic.

scholarly journals Uncertainties and assessments of chemistry-climate models of the stratosphere

2003 ◽  
Vol 3 (1) ◽  
pp. 1-27 ◽  
Author(s):  
J. Austin ◽  
D. Shindell ◽  
S. R. Beagley ◽  
C. Brühl ◽  
M. Dameris ◽  
...  
Keyword(s):  
Climate Models ◽  
Wave Drag ◽  
Horizontal Resolution ◽  
The Arctic ◽  
Cold Bias ◽  
Polar Regions ◽  
Wide Range ◽  
Antarctic Ozone ◽  
Stratospheric Clouds ◽  
The Antarctic

Abstract. In recent years a number of chemistry-climate models have been developed with an emphasis on the stratosphere. Such models cover a wide range of time scales of integration and vary considerably in complexity. The results of specific diagnostics are here analysed to examine the differences amongst individual models and observations, to assess the consistency of model predictions, with a particular focus on polar ozone. For example, many models indicate a significant cold bias in high latitudes, the "cold pole problem", particularly in the southern hemisphere during winter and spring. This is related to wave propagation from the troposphere which can be improved by improving model horizontal resolution and with the use of non-orographic gravity wave drag. As a result of the widely differing modelled polar temperatures, different amounts of polar stratospheric clouds are simulated which in turn result in varying ozone values in the models. The results are also compared to determine the possible future behaviour of ozone, with an emphasis on the polar regions and mid-latitudes. All models predict eventual ozone recovery, but give a range of results concerning its timing and extent. Differences in the simulation of gravity waves and planetary waves as well as model resolution are likely major sources of uncertainty for this issue. In the Antarctic, the ozone hole has probably reached almost its deepest although the vertical and horizontal extent of depletion may increase slightly further over the next few years. According to the model results, Antarctic ozone recovery could begin any year within the range 2001 to 2008. The limited number of models which have been integrated sufficiently far indicate that full recovery of ozone to 1980 levels may not occur in the Antarctic until about the year 2050. For the Arctic, most models indicate that small ozone losses may continue for a few more years and that recovery could begin any year within the range 2004 to 2019. The start of ozone recovery in the Arctic is therefore expected to appear later than in the Antarctic. Further, interannual variability will tend to mask the signal for longer than in the Antarctic, delaying still further the date at which ozone recovery may be said to have started. Because of this inherent variability of the system, the decadal evolution of Arctic ozone will not necessarily be a direct response to external forcing.

scholarly journals Evolution in the cold

2000 ◽  
Vol 12 (3) ◽  
pp. 257-257 ◽  
Author(s):  
Andrew Clarke
Keyword(s):  
Evolutionary Biology ◽  
Antarctic Fish ◽  
The Arctic ◽  
Polar Regions ◽  
Evolutionary Studies ◽  
Adaptive Radiations ◽  
The Antarctic ◽  
The Impact ◽  
Insight Into

Theodosius Dobzhansky once remarked that nothing in biology makes sense other than in the light of evolution, thereby emphasising the central role of evolutionary studies in providing the theoretical context for all of biology. It is perhaps surprising then that evolutionary biology has played such a small role to date in Antarctic science. This is particularly so when it is recognised that the polar regions provide us with an unrivalled laboratory within which to undertake evolutionary studies. The Antarctic exhibits one of the classic examples of a resistance adaptation (antifreeze peptides and glycopeptides, first described from Antarctic fish), and provides textbook examples of adaptive radiations (for example amphipod crustaceans and notothenioid fish). The land is still largely in the grip of major glaciation, and the once rich terrestrial floras and faunas of Cenozoic Gondwana are now highly depauperate and confined to relatively small patches of habitat, often extremely isolated from other such patches. Unlike the Arctic, where organisms are returning to newly deglaciated land from refugia on the continental landmasses to the south, recolonization of Antarctica has had to take place by the dispersal of propagules over vast distances. Antarctica thus offers an insight into the evolutionary responses of terrestrial floras and faunas to extreme climatic change unrivalled in the world. The sea forms a strong contrast to the land in that here the impact of climate appears to have been less severe, at least in as much as few elements of the fauna show convincing signs of having been completely eradicated.

scholarly journals Citroniella saccharovorans gen. nov. sp. nov., a member of the family Peptoniphilaceae isolated from a human fecal sample from a coastal traditional community member

2019 ◽  
Vol 69 (4) ◽  
pp. 1142-1148 ◽  
Author(s):  
Nisha B. Patel ◽  
Alexandra J. Obregón-Tito ◽  
Raul Y. Tito ◽  
Omar Trujillo-Villaroel ◽  
Luis Marin-Reyes ◽  
...  
Keyword(s):  
Fecal Sample ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
The Novel ◽  
Content Type ◽  
Link Type ◽  
Novel Bacterium ◽  
The Family ◽  
Diamino Acid ◽  
Rrna Gene Sequencing

A novel Gram-stain-positive, non-motile, non-spore-forming coccus-shaped obligately anaerobic bacterium was recovered from a fecal sample obtained from an individual from a traditional community located on the southern coast of Peru. The results of analysis based on 16S rRNA gene sequencing indicated the novel bacterium to be phylogenetically distinct from other genera of members of the Peptoniphilaceae family, sharing a loose affinity with the genera Ezakiella , Finegoldia , Gallicola and Parvimonas . The major cellular fatty acids of the novel isolate were determined to be C16:0, C17:1ω8c, and C18:1ω9c. The DNA G+C content was 29.9 mol%. End products of metabolism from peptone yeast glucose broth (PYG) were determined to be acetate and methyl succinate. The diagnostic diamino acid present in the cell wall was lysine. On the basis of the phenotypic, chemotaxonomic and phylogenetic results the organism is a member of a novel genus belonging to the family Peptoniphilaceae for which the name Citroniella saccharovorans gen nov. sp. nov., is proposed. The type strain is M6.X9T (DSM 29873T=CCUG 66799T).

scholarly journals Comparison of Small Gut and Whole Gut Microbiota of First-Degree Relatives with Adult Celiac Disease Patients and Controls

2017 ◽  
Author(s):  
Rahul Bodkhe ◽  
Sudarshan A. Shetty ◽  
Dhiraj P. Dhotre ◽  
Anil K. Verma ◽  
Khushbo Bhatia ◽  
...  
Keyword(s):  
Celiac Disease ◽  
Gut Microbiota ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Sequence Variant ◽  
First Degree Relatives ◽  
Adult Celiac Disease ◽  
Disease Site ◽  
Rrna Gene Sequencing ◽  
And Control

AbstractRecent studies on celiac disease (CeD) have shown the role of gut microbiota alterations in CeD pathogenesis. Whether this alteration in the microbial community is the cause or effect of the disease is not well understood, especially in adult onset of disease. The first-degree relatives (FDRs) of CeD patients may provide an opportunity to study gut microbiome in pre-disease state as FDRs are genetically susceptible to CeD. By using 16S rRNA gene sequencing, we observed between the disease condition (CeD), pre-disease (FDR) and control subjects. However, differences were observed at the level of amplicon sequence variant (ASV), suggesting alterations in specific taxa between pre-diseases and diseased condition. Duodenal biopsies showed higher differences in ASVs compared to faecal samples indicating larger disruption of microbiota at disease site. Increased abundance of specific Helicobacter ASVs were observed in duodenum of CeD when compared to FDR (p < 0.01). In case of fecal samples CeD microbiome and Actinomyces. In addition, predicted functional metagenome showed reduced ability of gluten that ecosystem level diversity measures (except in the duodenum) were not significantly different is characterized by reduced abundance of beneficial taxa such as Akkermansia, Ruminococcus degradation by CeD faecal microbiota in comparison to FDRs and controls.

scholarly journals BRICS in polar regions: Brazil’s interests and prospects

2020 ◽  
Vol 13 (3) ◽  
pp. 326-340
Author(s):  
Paulo Borba Casella ◽  
◽  
Maria Lagutina ◽  
Arthur Roberto Capella Giannattasio ◽  
◽  
...  
Keyword(s):  
Legal Regulation ◽  
The Arctic ◽  
Polar Regions ◽  
Arctic Council ◽  
Public Power ◽  
Promising Tool ◽  
Antarctic Treaty ◽  
International Power ◽  
Global Affairs ◽  
The Antarctic

The current international legal regulation of the Arctic and Antarctica was organized during the second half of the XX century to establish an international public power over the two regions, the Arctic Council (AC) and the Antarctic Treaty System (ATS), which is characterized by Euro-American dominance. However, the rise of emerging countries at the beginning of the XXI century suggests a progressive redefinition of the structural balance of international power in favor of states not traditionally perceived as European and Western. This article examines the role of Brazil within the AC and the ATS to address various polar issues, even institutional ones. As a responsible country in the area of cooperation in science and technology in the oceans and polar regions in BRICS, Brazil appeals to its rich experience in Antarctica and declares its interest in joining the Arctic cooperation. For Brazil, participation in polar cooperation is a way to increase its role in global affairs and BRICS as a negotiating platform. It is seen in this context as a promising tool to achieve this goal. This article highlights new paths in the research agenda concerning interests and prospects of Brazilian agency in the polar regions.

scholarly journals Long-chain diols in rivers: distribution and potential biological sources

2018 ◽  
Author(s):  
Julie Lattaud ◽  
Frédérique Kirkels ◽  
Francien Peterse ◽  
Chantal V. Freymond ◽  
Timothy I. Eglinton ◽  
...  
Keyword(s):  
River Flow ◽  
18S Rrna Gene ◽  
Rrna Gene ◽  
River Systems ◽  
Eukaryotic Diversity ◽  
Suspended Particulate ◽  
Fractional Abundance ◽  
Biological Sources ◽  
Rrna Gene Sequencing ◽  
Long Chain

Abstract. Long chain diols (LCDs) occur widespread in marine environments and also in lakes and rivers. Transport of LCDs from rivers may impact the distribution of LCDs in coastal environments, however relatively little is known about the distribution and biological sources of LCDs in river systems. In this study, we investigated the distribution of LCDs in suspended particulate matter (SPM) of three river systems (Godavari, Danube, and Rhine) in relation with season, precipitation, temperature, and source catchments. The dominant long-chain diol is the C32 1,15-diol followed by the C30 1,15-diol in all studied river systems. In regions influenced by marine waters, such as delta systems, the fractional abundance of the C30 1,15-diol is substantially higher than in the river itself, suggesting different LCD producers in marine and freshwater environments. A change in the LCD distribution along the downstream transects of the rivers studied was not observed. However, an effect of river flow is observed, i.e. the concentration of the C32 1,15-diol is higher in stagnant waters, such as reservoirs and during seasons with river low stands. A seasonal change in the LCD distribution was observed in the Rhine, likely due to a change in the producers. Eukaryotic diversity analysis by 18S rRNA gene sequencing of SPM from the Rhine showed extremely low abundances of sequences (i.e.

scholarly journals Emergence of Babesia Conradae Infection in Coyote-hunting Greyhounds in Oklahoma, USA

2021 ◽  
Author(s):  
Erin M Stayton ◽  
Megan Lineberry ◽  
Jennifer Thomas ◽  
Tina Bass ◽  
Kelly Allen ◽  
...  
Keyword(s):  
18S Rrna ◽  
Clinical Signs ◽  
18S Rrna Gene ◽  
Post Treatment ◽  
Rrna Gene ◽  
Babesia Gibsoni ◽  
Wide Range ◽  
Pcr Products ◽  
Life Threatening ◽  
Tick Vectors

Abstract Background: Babesia species are intraerythrocytic Apicomplexan parasites that infect a wide range of vertebrate hosts. These pathogens are typically transmitted either by tick vectors or by direct blood-to-blood contact, and may cause life-threatening clinical disease such as thrombocytopenia, hemolytic anemia, and acute renal failure in canine hosts. While Babesia vogeli and Babesia gibsoni infections have both been reported in Oklahoma, reports of B. conradae infections have been limited to California. Methods: Whole blood samples were collected in EDTA tubes from all dogs in four separate kennels in Oklahoma. DNA was extracted from each blood sample and a nested PCR was performed using general Apicomplexan primers for the partial 18S rRNA gene. PCR products were electrophoresed in agarose matrix and appropriately sized amplicons were sequenced. Sequences were compared to reference 18S rRNA sequences available in GenBank, and samples with >98% homology to B. conradae (GenBank MK256976) were considered positive. B. conradae positive dogs were then treated with atovaquone (13.5 mg/kg TID) and azithromycin (10 mg/kg SID) for 10 days and retested at 30 and 60 days post treatment by PCR. Results: Fifteen of 40 dogs tested positive for B. conradae with 98–100% sequence homology to B. conradae from California. All positive cases were coyote-hunting Greyhounds. Treatment of clinically ill dogs with atovaquone and azithromycin resulted in complete clinical recovery in clinically ill dogs and all treated dogs had negative follow-up PCR at 30 and 60 days post treatment. Conclusions: Collectively, this study (i) documents the occurrence of B. conradae in Oklahoma, (ii) highlights this pathogen as a differential to be considered when clinical signs are present, and (iii) supports the use of atovaquone and azithromycin as effective treatment in these cases.

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