89 research outputs found
Observation of time quasicrystal and its transition to superfluid time crystal
We report experimental realization of a quantum time quasicrystal, and its
transformation to a quantum time crystal. We study Bose-Einstein condensation
of magnons, associated with coherent spin precession, created in a flexible
trap in superfluid He-B. Under a periodic drive with an oscillating
magnetic field, the coherent spin precession is stabilized at a frequency
smaller than that of the drive, demonstrating spontaneous breaking of discrete
time translation symmetry. The induced precession frequency is incommensurate
with the drive, and hence the obtained state is a time quasicrystal. When the
drive is turned off, the self-sustained coherent precession lives a
macroscopically-long time, now representing a time crystal with broken symmetry
with respect to continuous time translations. Additionally, the magnon
condensate manifests spin superfluidity, justifying calling the obtained state
a time supersolid or a time super-crystal
Viroplasm and large virus-like particles in the dinoflagellate Gymnodinium uberrimum
Virus-like particles (VLPs) measuring 385±5 nm in diameter are described in the freshwater dinoflagellate Gymnodinium uberrimum . The VLPs are found in association with, and “budding” from a vesicular viroplasmic area. A similar viroplasm was also found in a chrysophycean alga, Mallomonas sp. collected from the same general area in Saginaw Bay of Lake Huron. The nature of these VLPs and their virogenic stroma, in these algae from the Laurentian Great Lakes are discussed in the present report.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41733/1/709_2005_Article_BF01275735.pd
Microbial diversity and biogeochemical cycling in soda lakes
Soda lakes contain high concentrations of sodium carbonates resulting in a stable elevated pH, which provide a unique habitat to a rich diversity of haloalkaliphilic bacteria and archaea. Both cultivation-dependent and -independent methods have aided the identification of key processes and genes in the microbially mediated carbon, nitrogen, and sulfur biogeochemical cycles in soda lakes. In order to survive in this extreme environment, haloalkaliphiles have developed various bioenergetic and structural adaptations to maintain pH homeostasis and intracellular osmotic pressure. The cultivation of a handful of strains has led to the isolation of a number of extremozymes, which allow the cell to perform enzymatic reactions at these extreme conditions. These enzymes potentially contribute to biotechnological applications. In addition, microbial species active in the sulfur cycle can be used for sulfur remediation purposes. Future research should combine both innovative culture methods and state-of-the-art ‘meta-omic’ techniques to gain a comprehensive understanding of the microbes that flourish in these extreme environments and the processes they mediate. Coupling the biogeochemical C, N, and S cycles and identifying where each process takes place on a spatial and temporal scale could unravel the interspecies relationships and thereby reveal more about the ecosystem dynamics of these enigmatic extreme environments
Actualization of the Universal Concept Leadership in Russian Conceptual Sphere of a New State Administration
The article is focused on the investigation of Leadership concept, which is universal for linguistic group structures. The concept is connected with the realization of traditional, hierarchical, and management principles reflecting the interacting specificity of state power branches. Special attention is given to the lexemes representing the concept. Transformations in their semantics determine the frequency growth and consequently influence the frequency in the usage of the analyzed concept
Semantics of a political word unit in modern russian language
The article deals with the problem of modern Russian social and political vocabulary specificity. The peculiarities of basic typological characteristics of a political word unit, i.e. ideological abusement, and originality of its reflection on the level of a word semantic structure and all semantic macro components of the meaning are observed in the paper. Special attention is paid to the description of semantic and stylistic neutralization processes in the meaning of political lexical units in modern Russian and their mainstreams
The Conjugates of Phenolic Acids in Lichens of the Order Lecanorales
Lichens are symbiotic associations of a fungus (usually an ascomycete) and a photobiont, which may be an alga and/or a cyanobacterium. Lichens dominate on about 6–8% of land surface, mainly in the habitats with severe climatic conditions. Lichenized fungi are among the pioneer vegetation on bare rock or soil. Mat-forming species contribute substantially to the soil cover in tundras and high mountain elevations. Lichens are rich in water-soluble compounds which can be leached-out the lichen thalli with atmospheric depositions. We have recently described the occurrence of water-soluble phenolics in lichens (Zagoskina et al 2013). These compounds can play important role in the ecosystem functioning and primary soil formation (weathering, humification). The aim of this work was to study qualitative composition of water-soluble phenolics in the lichen species widespread in the soil cover of tundra zone. The air-dried thalli of Alectoria ochroleuca, Cetraria islandica, C.nigricans, C.nivalis, Cladonia arbuscula and C.stellaris were homogenized to powder and used for the study. Lichens were collected in Khibiny mountains, Kola Peninsula in August 2013. Phenolic compounds were extracted by distilled water (1h, 30C) and analyzed by TLC before and after the acid hydrolysis. It was found that all the lichens under the study contained the conjugates of phenol carboxylic acids. We have identified that non-phenolic part in some of these conjugates was represented by sugars and amino acids. The TLC of the hydrolizates of water extracts revealed occurrence of p-oxybenzoic acid in all of the species studied. The lichens Cetraria islandica, С.nigricans and Cladonia stellaris contained also vanillic acid. These phenolic acids are widespread in plant kingdom and are known as products of lignin decomposition in higher plants. The physiological role of water-soluble phenolics in lichens as well as their environmental role are need to be understood in future studies.</p
The Conjugates of Phenolic Acids in Lichens of the Order Lecanorales
Lichens are symbiotic associations of a fungus (usually an ascomycete) and a photobiont, which may be an alga and/or a cyanobacterium. Lichens dominate on about 6–8% of land surface, mainly in the habitats with severe climatic conditions. Lichenized fungi are among the pioneer vegetation on bare rock or soil. Mat-forming species contribute substantially to the soil cover in tundras and high mountain elevations. Lichens are rich in water-soluble compounds which can be leached-out the lichen thalli with atmospheric depositions. We have recently described the occurrence of water-soluble phenolics in lichens (Zagoskina et al 2013). These compounds can play important role in the ecosystem functioning and primary soil formation (weathering, humification). The aim of this work was to study qualitative composition of water-soluble phenolics in the lichen species widespread in the soil cover of tundra zone. The air-dried thalli of Alectoria ochroleuca, Cetraria islandica, C.nigricans, C.nivalis, Cladonia arbuscula and C.stellaris were homogenized to powder and used for the study. Lichens were collected in Khibiny mountains, Kola Peninsula in August 2013. Phenolic compounds were extracted by distilled water (1h, 30C) and analyzed by TLC before and after the acid hydrolysis. It was found that all the lichens under the study contained the conjugates of phenol carboxylic acids. We have identified that non-phenolic part in some of these conjugates was represented by sugars and amino acids. The TLC of the hydrolizates of water extracts revealed occurrence of p-oxybenzoic acid in all of the species studied. The lichens Cetraria islandica, С.nigricans and Cladonia stellaris contained also vanillic acid. These phenolic acids are widespread in plant kingdom and are known as products of lignin decomposition in higher plants. The physiological role of water-soluble phenolics in lichens as well as their environmental role are need to be understood in future studies
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