30 research outputs found

    Genetic integrity of four species of Leptidea (Pieridae, Lepidoptera) as sampled in sympatry in West Siberia

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    In southern West Siberia, as many as four Leptidea Billberg, 1820 species are present sympatrically: L. amurensis (Ménétriés, 1859), L. morsei (Ménétriés, 1859), L. sinapis (Linnaeus, 1758) and L. juvernica Williams, 1946. The two latter were recently recognised as nearly sibling species on morphological and molecular characters. Specimens intermediate as to their subtle diagnostic characters occurring in West Siberia and elsewhere were interpreted as resulted from limited introgression. This supposition was tested via populational morphological and molecular analysis of spring brood specimens of all the four species taken from a limited (4.5 × 0.2 km) area in the suburbs of Novosibirsk. The samples were analysed with respect to the genitalic morphology, external characters, three nuclear (CAD, H1 gene and ITS2) and one mitochondrial (COI) molecular markers, infection of the intracellular maternally inherited bacterial symbiont Wolbachia Hertig, 1836 and its wsp gene coding for a hypervariable surface protein. Interspecific variation of the nuclear CAD and ITS2 sequences and the mitochondrial COI gene in L. sinapis and L. juvernica turned out concordant. The absence of molecular evidence of introgression suggests genetic integrity of these two species and allows their reliable identification by molecular characters. The genitalic (lengths of the saccus and valva) and external characters (wing pattern) of males overlap in L. sinapis and L. juvernica, as identified by molecular markers and thus are not so helpful in actual species identification. Only the ductus bursae length showed no overlap and can be used for identification of females. The histone H1 gene appeared five times less variable over the four studied species than COI, and found to be identical in species L. sinapis and L. juvernica. Wolbachia infection was found in all studied species. We identified three wsp variants of Wolbachia: 1) wsp-10 allele in L. amurensis, L. sinapis, L. juvernica; 2) a very similar wsp-687 allele in L. sinapis; and 3) wsp-688, highly divergent to the previous ones, in L. morsei

    Results of instrumental aerial survey of ice-associated seals on the ice in the Okhotsk Sea in May 2013

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    Populations of ice-associated seals in the Okhotsk Sea are assessed using modern instrumental aerial technique. The aerial survey was conducted over a part of the ice-covered area of the Sea on May 1-9, 2013 by means of thermal scan and visual digital photography from the aircraft-laboratory An-38 «Vostok». The ice covered area of the Okhotsk Sea in the time of survey was estimated as 242,000 km2, and 2,993 km2 of it was covered by survey transects with total length 5,617 km. The number of animals on all transects within the equipment swath was counted. Four seal species were identified: bearded, spotted, ribbon, and ringed seals, and their number and distribution were determined. The infra-red scanner recorded 5,730 seals on the ice and 4,360 these animals were photographed including 844 ringed seals, 453 bearded, 721 spotted, 1,805 ribbon, 435 pups non-identified to the species, and 102 non-identified to species adult seals. These assessments were extrapolated over the whole ice-covered area of the Okhotsk Sea using a linear model framework, and the following estimations of the species total abundance were presented (95 % confidence intervals in brackets): 88,253 (64,120-130,320) ringed seals, 39,743 (27,868-60,026) bearded seals, 181,179 (118,392-316,995) ribbon seals, and 84,356 (55,172-113,540) spotted seals. A database on all recorded seals with their «portrait-photos» and accompanying information is created on materials of the aerial survey. The developed instrumental technology can be used as a basis for wider aerial surveys of ice-associated seals in the North Pacific

    Coulomb correlation and magnetic ordering in double-layered manganites: LaSr2_2Mn2_2O7_7

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    A detailed study of the electronic structure and magnetic configurations of the 50 % hole-doped double layered manganite LaSr2_2Mn2_2O7_7 is presented. We demonstrate that the on-site Coulomb correlation (U) of Mn d electrons {\it (i)} significantly modifies the electronic structure, magnetic ordering (from FM to AFM), and interlayer exchange interactions, and {\it (ii)} promotes strong anisotropy in electrical transport, reducing the effective hopping parameter along the {\it c} axis for electrically active ege_g electrons. This findng is consistent with observations of anisotropic transport -- a property which sets this manganite apart from conventional 3D systems. A half-metallic band structure is predicted with both the LSDA and LSDA+U methods. The experimentally observed A-type AFM ordering in LaSr2_2Mn2_2O7_7 is found to be energetically more favorable with U \geq 7 eV. A simple interpretation of interlayer exchange coupling is given within double and super-exchange mechanisms based on the dependencies on U of the effective exchange parameters and ege_g state sub-band widths.Comment: 10 pages, 5 figure

    High Sensitivity TSS Prediction: Estimates of Locations Where TSS Cannot Occur

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    Although transcription in mammalian genomes can initiate from various genomic positions (e.g., 3′UTR, coding exons, etc.), most locations on genomes are not prone to transcription initiation. It is of practical and theoretical interest to be able to estimate such collections of non-TSS locations (NTLs). The identification of large portions of NTLs can contribute to better focusing the search for TSS locations and thus contribute to promoter and gene finding. It can help in the assessment of 5′ completeness of expressed sequences, contribute to more successful experimental designs, as well as more accurate gene annotation.Using comprehensive collections of Cap Analysis of Gene Expression (CAGE) and other transcript data from mouse and human genomes, we developed a methodology that allows us, by performing computational TSS prediction with very high sensitivity, to annotate, with a high accuracy in a strand specific manner, locations of mammalian genomes that are highly unlikely to harbor transcription start sites (TSSs). The properties of the immediate genomic neighborhood of 98,682 accurately determined mouse and 113,814 human TSSs are used to determine features that distinguish genomic transcription initiation locations from those that are not likely to initiate transcription. In our algorithm we utilize various constraining properties of features identified in the upstream and downstream regions around TSSs, as well as statistical analyses of these surrounding regions.

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Odonata found in mid-summer 2015 and 2016 at the north-westernmost Black Sea Coast of the Caucasus, with the first record of Cordulegaster picta Selys, 1854 in Russian Federation // Calopteryx virgo feminalis subsp. nov., a long known under the same name but hitherto formally nameless subspecies from the Caucasian Black Sea Coast

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    Part 1, Oleg E. Kosterin and Vladimir I. Solovyev, page 1-43: Odonata found in mid-summer 2015 and 2016 at the north-westernmost Black Sea Coast of the Caucasus, with the first record of Cordulegaster picta Selys, 1854 in Russian Federation Abstract: Results are presented of brief odonatological examination of the Black Sea coastal northwesternmost spurs of the Caucasus between Anapa and Gelendzhik (mostly at Kabardinka village), Russia, in late July/early August 2015 and early-mid July 2016. In total, 28 Odonata species were found, including Cordulegaster picta for the first time in Russia. For C. picta and Caliaeschna microstigma, the world’s northernmost records were made. New localities of species rare in this area are reported: one for Coenagrion scitulum and three for Selysiothemis nigra, including their breeding habitat. Numerous migrant individuals of Pantala flavescens were observed in many localities in 2015 but none in 2016. Observations on trophic activity of Aeshna affinis and A. mixta are reported, the former showing predominantly matutinal and vespertinal activity and the latter diurnal activity. Occurrence of the Chalcolestes spp. in the Caucasus is discussed. Part 2, Oleg E. Kosterin, page 45 - 57: Calopteryx virgo feminalis subsp. nov., a long known under the same name but hitherto formally nameless subspecies from the Caucasian Black Sea Coast Abstract: The populations of Calopteryx virgo of the Black Sea Coast of the Caucasus have females with the distal hindwing part darkened and males with the underside of S10 and appendages whitish, They are known for more than a century and deserve a subspecific status but since the name feminalis Bartenev, 1910 proposed to them is unavailable, a new subspecies is formally erected under the same name, Calopteryx virgo feminalis Kosterin subsp. nov., with the following type locality: Russia, Krasnodarskiy Kray, Gelendzhik Municipality, Kabardinka village, the Doob River lowermost reaches, 44°38'26-53'', 37°55'55''-57'58'' E
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