scholarly journals Microspongium alariae in Alaria esculenta: a widely-distributed non-parasitic brown algal endophyte that shows cell modifications within its host

2018 ◽  
Vol 61 (4) ◽  
pp. 343-354 ◽  
Author(s):  
Pedro Murúa ◽  
Frithjof C. Küpper ◽  
Liliana A. Muñoz ◽  
Miriam Bernard ◽  
Akira F. Peters
Keyword(s):  
Wide Distribution ◽  
The Arctic ◽  
Northern Europe ◽  
Cell Diameter ◽  
Economic Potential ◽  
Mitochondrial Coi ◽  
Adaptive Value ◽  
Alaria Esculenta ◽  
First Time ◽  
Nw Europe

Abstract Alaria esculenta is an important kelp species in northern Europe, Atlantic Canada and USA and the Arctic, with high economic potential. Microspongium alariae, a brown algal endophyte using A. esculenta as host, is reported for the first time from Scotland (Great Britain) and Brittany (France), suggesting a wide distribution in NW Europe. The alga was found growing epi-endophytically in A. esculenta stipes and was occasionally associated with warts. Isolated Microspongium thalli grew in host-free cultures and formed plurilocular sporangia in a broad range of temperature and irradiance conditions. DNA barcoding using the nuclear ribosomal ITS1, the mitochondrial COI and the plastidial rbcL confirmed the identity of the endophyte as M. alariae. Electron microscopy was used to compare the alga when endophytic in Alaria with a host-free culture. As an endophyte, cell diameter, pyrenoid diameter and cell wall thickness were reduced. In contrast, there were more plasmodesma connections between endophyte cells, possibly to enhance nutrient transport along the endophytic thallus. In the light of this evidence, a parasitic life style is considered unlikely for the species and the adaptive value of endophytism in M. alariae remains to be elucidated.

A Well-Ordered Thing

2018 ◽  
Author(s):  
Michael D. Gordin
Keyword(s):  
Nineteenth Century ◽  
History Of Science ◽  
Periodic Table ◽  
The Arctic ◽  
Classic Work ◽  
Hot Air ◽  
History Of ◽  
First Time

Dmitrii Mendeleev (1834–1907) is a name we recognize, but perhaps only as the creator of the periodic table of elements. Generally, little else has been known about him. This book is an authoritative biography of Mendeleev that draws a multifaceted portrait of his life for the first time. As the book reveals, Mendeleev was not only a luminary in the history of science, he was also an astonishingly wide-ranging political and cultural figure. From his attack on Spiritualism to his failed voyage to the Arctic and his near-mythical hot-air balloon trip, this is the story of an extraordinary maverick. The ideals that shaped his work outside science also led Mendeleev to order the elements and, eventually, to engineer one of the most fascinating scientific developments of the nineteenth century. This book is a classic work that tells the story of one of the world's most important minds.

Professional pathology in the production of aluminum in the Kola Arctic

2020 ◽  
pp. 767-767
Author(s):  
S. A. Syurin ◽  
S. A. Gorbanev
Keyword(s):  
Working Conditions ◽  
Occupational Diseases ◽  
Scientific Explanation ◽  
Marked Decrease ◽  
The Arctic ◽  
Aluminium Production ◽  
First Time

In 2007-2017, 22 occupational diseases were diagnosed for the first time in 18 workers engaged in aluminium production in the Arctic. A marked decrease in occupational morbidity in 2010-2017 was found, which was not associated with changes in working conditions and therefore requires an appropriate scientific explanation.

scholarly journals Phylogeography of the Brittle Star Ophiura sarsii Lütken, 1855 (Echinodermata: Ophiuroidea) from the Barents Sea and East Atlantic

Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 40
Author(s):  
Evgeny Genelt-Yanovskiy ◽  
Yixuan Li ◽  
Ekaterina Stratanenko ◽  
Natalia Zhuravleva ◽  
Natalia Strelkova ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Barents Sea ◽  
Haplotype Diversity ◽  
Brittle Star ◽  
The Arctic ◽  
Coi Gene ◽  
High Genetic Diversity ◽  
Svalbard Archipelago ◽  
Mitochondrial Coi ◽  
The Barents Sea

Ophiura sarsii is a common brittle star species across the Arctic and Sub-Arctic regions of the Atlantic and the Pacific oceans. Ophiurasarsii is among the dominant echinoderms in the Barents Sea. We studied the genetic diversity of O.sarsii by sequencing the 548 bp fragment of the mitochondrial COI gene. Ophiurasarsii demonstrated high genetic diversity in the Barents Sea. Both major Atlantic mtDNA lineages were present in the Barents Sea and were evenly distributed between the northern waters around Svalbard archipelago and the southern part near Murmansk coast of Kola Peninsula. Both regions, and other parts of the O.sarsii range, were characterized by high haplotype diversity with a significant number of private haplotypes being mostly satellites to the two dominant haplotypes, each belonging to a different mtDNA clade. Demographic analyses indicated that the demographic and spatial expansion of O.sarsii in the Barents Sea most plausibly has started in the Bølling–Allerød interstadial during the deglaciation of the western margin of the Barents Sea.

scholarly journals Biosynthesis of anandamide and N-palmitoylethanolamine by sequential actions of phospholipase A2 and lysophospholipase D

2004 ◽  
Vol 380 (3) ◽  
pp. 749-756 ◽  
Author(s):  
Yong-Xin SUN ◽  
Kazuhito TSUBOI ◽  
Yasuo OKAMOTO ◽  
Takeharu TONAI ◽  
Makoto MURAKAMI ◽  
...  
Keyword(s):  
Biosynthetic Pathway ◽  
Brain Homogenate ◽  
Wide Distribution ◽  
Rat Tissues ◽  
Lysophospholipase D ◽  
Pla2 Enzyme ◽  
First Time ◽  
Hydrolysis Of ◽  
The Brain

Anandamide (an endocannabinoid) and other bioactive long-chain NAEs (N-acylethanolamines) are formed by direct release from N-acyl-PE (N-acyl-phosphatidylethanolamine) by a PLD (phospholipase D). However, the possible presence of a two-step pathway from N-acyl-PE has also been suggested previously, which comprises (1) the hydrolysis of N-acyl-PE to N-acyl-lysoPE by PLA1/PLA2 enzyme(s) and (2) the release of NAEs from N-acyllysoPE by lysoPLD (lysophospholipase D) enzyme(s). In the present study we report for the first time the characterization of enzymes responsible for this pathway. The PLA1/PLA2 activity for N-palmitoyl-PE was found in various rat tissues, with the highest activity in the stomach. This stomach enzyme was identified as group IB sPLA2 (secretory PLA2), and its product was determined as N-acyl-1-acyl-lysoPE. Recombinant group IB, IIA and V of sPLA2s were also active with N-palmitoyl-PE, whereas group X sPLA2 and cytosolic PLA2α were inactive. In addition, we found wide distribution of lysoPLD activity generating N-palmitoylethanolamine from N-palmitoyl-lysoPE in rat tissues, with higher activities in the brain and testis. Based on several lines of enzymological evidence, the lysoPLD enzyme could be distinct from the known N-acyl-PE-hydrolysing PLD. sPLA2-IB dose dependently enhanced the production of N-palmitoylethanolamine from N-palmitoyl-PE in the brain homogenate showing the lysoPLD activity. N-Arachidonoyl-PE and N-arachidonoyl-lysoPE as anandamide precursors were also good substrates of sPLA2-IB and the lysoPLD respectively. These results suggest that the sequential actions of PLA2 and lysoPLD may constitute another biosynthetic pathway for NAEs, including anandamide.

scholarly journals Record-breaking ozone loss in the Arctic winter 2010/2011: comparison with 1996/1997

2012 ◽  
Vol 12 (15) ◽  
pp. 7073-7085 ◽  
Author(s):  
J. Kuttippurath ◽  
S. Godin-Beekmann ◽  
F. Lefèvre ◽  
G. Nikulin ◽  
M. L. Santee ◽  
...  
Keyword(s):  
Transport Model ◽  
Chemical Transport ◽  
The Arctic ◽  
Altitude Range ◽  
Chemical Transport Model ◽  
Model Simulations ◽  
Ozone Loss ◽  
Elevated Ozone ◽  
Record Value ◽  
First Time

Abstract. We present a detailed discussion of the chemical and dynamical processes in the Arctic winters 1996/1997 and 2010/2011 with high resolution chemical transport model (CTM) simulations and space-based observations. In the Arctic winter 2010/2011, the lower stratospheric minimum temperatures were below 195 K for a record period of time, from December to mid-April, and a strong and stable vortex was present during that period. Simulations with the Mimosa-Chim CTM show that the chemical ozone loss started in early January and progressed slowly to 1 ppmv (parts per million by volume) by late February. The loss intensified by early March and reached a record maximum of ~2.4 ppmv in the late March–early April period over a broad altitude range of 450–550 K. This coincides with elevated ozone loss rates of 2–4 ppbv sh−1 (parts per billion by volume/sunlit hour) and a contribution of about 30–55% and 30–35% from the ClO-ClO and ClO-BrO cycles, respectively, in late February and March. In addition, a contribution of 30–50% from the HOx cycle is also estimated in April. We also estimate a loss of about 0.7–1.2 ppmv contributed (75%) by the NOx cycle at 550–700 K. The ozone loss estimated in the partial column range of 350–550 K exhibits a record value of ~148 DU (Dobson Unit). This is the largest ozone loss ever estimated in the Arctic and is consistent with the remarkable chlorine activation and strong denitrification (40–50%) during the winter, as the modeled ClO shows ~1.8 ppbv in early January and ~1 ppbv in March at 450–550 K. These model results are in excellent agreement with those found from the Aura Microwave Limb Sounder observations. Our analyses also show that the ozone loss in 2010/2011 is close to that found in some Antarctic winters, for the first time in the observed history. Though the winter 1996/1997 was also very cold in March–April, the temperatures were higher in December–February, and, therefore, chlorine activation was moderate and ozone loss was average with about 1.2 ppmv at 475–550 K or 42 DU at 350–550 K, as diagnosed from the model simulations and measurements.

scholarly journals Improving the inverse modeling of a trace isotope: how precisely can radium-228 fluxes toward the ocean and submarine groundwater discharge be estimated?

2017 ◽  
Vol 14 (13) ◽  
pp. 3171-3189 ◽  
Author(s):  
Guillaume Le Gland ◽  
Laurent Mémery ◽  
Olivier Aumont ◽  
Laure Resplandy
Keyword(s):  
Ocean Circulation ◽  
Inverse Modeling ◽  
Submarine Groundwater Discharge ◽  
Groundwater Discharge ◽  
Radioactive Decay ◽  
The Arctic ◽  
Time Data ◽  
Global Estimate ◽  
Submarine Groundwater ◽  
First Time

Abstract. Radium-228 (228Ra), an almost conservative trace isotope in the ocean, supplied from the continental shelves and removed by a known radioactive decay (T1∕2 = 5. 75 years), can be used as a proxy to constrain shelf fluxes of other trace elements, such as nutrients, iron, or rare earth elements. In this study, we perform inverse modeling of a global 228Ra dataset (including GEOSECS, TTO and GEOTRACES programs, and, for the first time, data from the Arctic and around the Kerguelen Islands) to compute the total 228Ra fluxes toward the ocean, using the ocean circulation obtained from the NEMO 3.6 model with a 2° resolution. We optimized the inverse calculation (source regions, cost function) and find a global estimate of the 228Ra fluxes of 8.01–8. 49 × 1023 atoms yr−1, more precise and around 20 % lower than previous estimates. The largest fluxes are in the western North Atlantic, the western Pacific and the Indian Ocean, with roughly two-thirds in the Indo-Pacific Basin. An estimate in the Arctic Ocean is provided for the first time (0.43–0.50  ×  1023 atoms yr−1). Local misfits between model and data in the Arctic, the Gulf Stream and the Kuroshio regions could result from flaws of the ocean circulation in these regions (resolution, atmospheric forcing). As radium is enriched in groundwater, a large part of the 228Ra shelf sources comes from submarine groundwater discharge (SGD), a major but poorly known pathway for terrestrial mineral elements, including nutrients, to the ocean. In contrast to the 228Ra budget, the global estimate of SGD is rather unconstrained, between 1.3 and 14. 7 × 1013 m3 yr−1, due to high uncertainties on the other sources of 228Ra, especially diffusion from continental shelf sediments. Better precision on SGD cannot be reached by inverse modeling until a proper way to separate the contributions of SGD and diffusive release from sediments at a global scale is found.

First report of reticulate perforation plates in the Melastomataceae

IAWA Journal ◽  
2014 ◽  
Vol 35 (1) ◽  
pp. 12-18
Author(s):  
Alessandra Ribeiro Guimarães ◽  
José Fernando A. Baumgratz ◽  
Ricardo Cardoso Vieira
Keyword(s):  
Structure Function ◽  
Wood Anatomy ◽  
Parallel Evolution ◽  
First Report ◽  
Adaptive Value ◽  
Perforation Plates ◽  
First Time

For the first time, the occurrence of reticulate perforation plates in Melastomataceae is reported. They were discovered in the course of a study of the wood anatomy of the tribe Microlicieae. The occurrence and frequency of the types of plates are discussed with respect to their structure, function, and environment. The reticulate perforation plates seem to be the result of parallel evolution. Some speculations are offered about their possible adaptive value.

scholarly journals Evolution of the seasonal temperature cycle in a transient Holocene simulation: orbital forcing and sea-ice

2011 ◽  
Vol 7 (1) ◽  
pp. 463-483 ◽  
Author(s):  
N. Fischer ◽  
J. H. Jungclaus
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
The Arctic ◽  
Northern Europe ◽  
Temperature Cycle ◽  
Surface Model ◽  
Seasonal Temperature ◽  
Ice Dynamics ◽  
Summer Insolation ◽  
The Arctic Ocean

Abstract. Changes in the Earth's orbit lead to changes in the seasonal and meridional distribution of insolation. We quantify the influence of orbitally induced changes on the seasonal temperature cycle in a transient simulation of the last 6000 years – from the mid-Holocene to today – using a coupled atmosphere-ocean general circulation model (ECHAM5/MPI-OM) including a land surface model (JSBACH). The seasonal temperature cycle responds directly to the insolation changes almost everywhere. In the Northern Hemisphere, its amplitude decreases according to an increase in winter insolation and a decrease in summer insolation. In the Southern Hemisphere, the opposite is true. Over the Arctic Ocean, however, decreasing summer insolation leads to an increase of sea-ice cover. The insulating effect of sea ice between the ocean and the atmosphere favors more continental conditions over the Arctic Ocean in winter, resulting in strongly decreasing temperatures. Consequently, there are two competing effects: the direct response to insolation changes and a sea-ice dynamics feedback. The sea-ice feedback is stronger, and thus an increase in the amplitude of the seasonal cycle over the Arctic Ocean occurs. This increase is strongest over the Barents Shelf and influences the temperature response over northern Europe. We compare our modelled seasonal temperatures over Europe to paleo reconstructions. We find better agreements in winter temperatures than in summer temperatures and better agreements in northern Europe than in southern Europe, since the model does not reproduce the southern European Holocene summer cooling inferred from the paleo data. The temperature reconstructions for northern Europe support the notion of the influence of the sea-ice effect on the evolution of the seasonal temperature cycle.

scholarly journals Taxonomy of the Empria hungarica species-group (Hymenoptera, Tenthredinidae) in Northern Europe

1999 ◽  
Vol 10 (2) ◽  
pp. 95-101 ◽  
Author(s):  
Mikk Heidemaa ◽  
Matti Viitasaari
Keyword(s):  
Species Group ◽  
Northern Europe ◽  
European Species ◽  
Diagnostic Characters ◽  
Northern European ◽  
First Time

In the tenthredinid hymenopteran genus Empria, the European species with a paired whitish patch on tergum 1 are considered tentatively as a species-group termed the E. hungarica group. The type materials of Empria pumila (Konow), E. pumiloides Lindqvist and E. tricornis Lindqvist were examined. The lectotype and paralectotypes of E. pumila are designated, and new diagnostic characters for E. pumila and E. pumiloides are given. A key for the Northern European species of the E. hungarica group is compiled. The results of a comparison of the phenology and some metrical characters of the adults of E. pumila and E. pumiloides are presented in the form of diagrams. E. pumiloides is recorded for the first time from Russia and Germany. The records of E. hungarica from Estonia (Saaremaa) are reported as the northernmost for that species. All available distributional records of Empria hungarica in the Palaearctic are given in the text, and those localized reliably are also mapped.

scholarly journals Occurrence of Amblyomma rotundatum Koch, 1844 on Epicrates assisi Machado, 1945 in João Pessoa, Paraíba, Brazil

2021 ◽  
Vol 15 (4) ◽  
pp. 335-338
Author(s):  
Aksa Ingrid Vieira Batista ◽  
Gabriel Vinicius Carvalho de Lucena ◽  
Kleber Silva de Oliveira Filho ◽  
Thiago Ferreira Lopes Nery ◽  
Thiago Fernandes Martins ◽  
...  
Keyword(s):  
Host Species ◽  
Tick Species ◽  
Wide Distribution ◽  
Dorsal Region ◽  
Taxonomic Key ◽  
Caatinga Biome ◽  
First Occurrence ◽  
First Time ◽  
Semi Arid

The Caatinga rainbow boa (Epicrates assisi Machado, 1945) is a snake belonging to the order Squamata, family Boidae, and subfamily Boinae. It has a wide distribution in Brazil and can be found in the Caatinga biome. The present study aims to report the first occurrence of Amblyomma rotundatum on E. assisi in the municipality of João Pessoa, Paraíba State (PB). On March 3, 2020, a tick collection was performed on the dorsal region of the head of an E. assisi, which was captive at the Arruda Câmara Zoobotanical Park, João Pessoa-PB. After collecting the tick, it was transferred to a flask containing 70º alcohol and sent to the Laboratory of Animal Parasitology of the Federal Rural University of the Semi-Arid (UFERSA) for analysis. Identification was done with the aid of a stereomicroscope using a taxonomic key. The result identified this specimen as a nymph of A. rotundatum. The occurrence of this tick species on E. assisi is reported for the first time and constitutes new data applicable to the ectoparasites that occur in this host species in Brazil.

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