259 research outputs found

    Нефтебитумопроявления в надкунгурских отложениях северо-восточных районов Волго-Уральской нефтегазоносной провинции

    Get PDF
    In result of comprehensive study, the areas of development and nature of oil and bitumen accumulation in Solikamsk and Sheshminskiy sediments at the North-Eastern regions of the Volga-Ural oil and gas province (the territory of Perm Krai, Udmurt Republic and Kirov Region) were established. The Ufimian layer was divided into two zones of oil and bitumen accumulations – Kuchukovsko-Karakulinskaya and Kuedinskaya. Formation of oil and bitumen accumulations in sediments overlaying the Kungurian is divided into four phases. The presence of hydrocarbons in the Ufimian sediments may be considered as an evidence of existence of the upper boundary of oil and gas potential of Paleozoic strata in the North-East of the Volga-Ural oil and gas province.Установлены ареалы развития и характер нефтебитумопроявлений в соликамских и шешминских отложениях в северо-восточных районах Волго-Уральской НГП (территории Пермского края, Удмуртской Республики и Кировской области). В уфимских отложениях выделены Кучуковско-Каракулинская и Куединская битумоносные зоны. Формирование нефтебитумоскоплений в надкунгурских отложениях подразделяется на четыре фазы. Наличие углеводородов  в уфимских отложениях может рассматриваться как проявление верхней границы нефтегазоносности палеозойского разреза на северовостоке Волго-Уральской нефтегазоносной провинции. Ареалы рекомендуется учитывать при бассейновом моделировании

    Dark solitons in ferromagnetic chains with first- and second-neighbor interactions

    Full text link
    We study the ferromagnetic spin chain with both first- and second-neighbor interactions. We obtained the condition for the appearance and stability of bright and dark solitons for arbitrary wave number inside the Brillouin zone. The influence of the second-neighbor interaction and the anisotropy on the soliton properties is considered. The scattering of dark solitons from point defects in the discrete spin chain is investigated numerically.Comment: 7 pages,5 figure

    Effect of electron irradiation on vortex dynamics in YBa_2Cu_3O_{7-x} single crystals

    Full text link
    We report on drastic change of vortex dynamics with increase of quenched disorder: for rather weak disorder we found a single vortex creep regime, which we attribute to a Bragg-glass phase, while for enhanced disorder we found an increase of both the depinning current and activation energy with magnetic field, which we attribute to entangled vortex phase. We also found that introduction of additional defects always increases the depinning current, but it increases activation energy only for elastic vortex creep, while it decreases activation energy for plastic vortex creep.Comment: 4 pages, 3 figures, submited to Phys. Rev.

    Uniparental Genetic Heritage of Belarusians: Encounter of Rare Middle Eastern Matrilineages with a Central European Mitochondrial DNA Pool

    Get PDF
    Ethnic Belarusians make up more than 80% of the nine and half million people inhabiting the Republic of Belarus. Belarusians together with Ukrainians and Russians represent the East Slavic linguistic group, largest both in numbers and territory, inhabiting East Europe alongside Baltic-, Finno-Permic- and Turkic-speaking people. Till date, only a limited number of low resolution genetic studies have been performed on this population. Therefore, with the phylogeographic analysis of 565 Y-chromosomes and 267 mitochondrial DNAs from six well covered geographic sub-regions of Belarus we strove to complement the existing genetic profile of eastern Europeans. Our results reveal that around 80% of the paternal Belarusian gene pool is composed of R1a, I2a and N1c Y-chromosome haplogroups – a profile which is very similar to the two other eastern European populations – Ukrainians and Russians. The maternal Belarusian gene pool encompasses a full range of West Eurasian haplogroups and agrees well with the genetic structure of central-east European populations. Our data attest that latitudinal gradients characterize the variation of the uniparentally transmitted gene pools of modern Belarusians. In particular, the Y-chromosome reflects movements of people in central-east Europe, starting probably as early as the beginning of the Holocene. Furthermore, the matrilineal legacy of Belarusians retains two rare mitochondrial DNA haplogroups, N1a3 and N3, whose phylogeographies were explored in detail after de novo sequencing of 20 and 13 complete mitogenomes, respectively, from all over Eurasia. Our phylogeographic analyses reveal that two mitochondrial DNA lineages, N3 and N1a3, both of Middle Eastern origin, might mark distinct events of matrilineal gene flow to Europe: during the mid-Holocene period and around the Pleistocene-Holocene transition, respectively

    ИНТРАПЕРИТОНЕАЛЬНОЕ ХИМИОПЕРФУЗИОННОЕ ЛЕЧЕНИЕ ДИССЕМИНИРОВАННОГО РАКА ЯИЧНИКА ДИОКСАДЭТОМ В СРАВНЕНИИ С ЦИСПЛАТИНОМ В ЭКСПЕРИМЕНТЕ

    Get PDF
    Comparative study of antitumor activity of cisplatin and dioxadet in chemoperfusion treatment was carried out on ascitic ovarian cancer model in 172 Vistar female rats. Ovarian cancer was inoculated intraperitoneally at a volume of 0.5 ml per rat with concentration of tumor cells 2×107 / ml. The drugs were administered once in 48 hours after inoculation of ovarian cancer in maximum tolerated doses (MTD). Normothermic intraperitoneal chemoperfusion (IPEC) and hyperthermic intraperitoneal chemoperfusion (HIPEC) were performed with cisplatin or dioxadet at doses that were 5−20 times higher than those for their standard intraperitoneal administration. Antitumor effects of the drugs were estimated in increase of median survival time (MST). In case of IPEC and HIPEC cisplatin increased the MST by 317  % and 183  % (р<0.05) respectively, when dioxadet increased the MST by 244  % and 444  % (р<0.05) respectively compared to the control group of animals that didn’t receive any treatment. HIPEC with dioxadet is the most effective regimen in experimental treatment of advanced ovarian cancer

    Species Diversity and Phylogeographical Affinities of the Branchiopoda (Crustacea) of Churchill, Manitoba, Canada

    Get PDF
    The region of Churchill, Manitoba, contains a wide variety of habitats representative of both the boreal forest and arctic tundra and has been used as a model site for biodiversity studies for nearly seven decades within Canada. Much previous work has been done in Churchill to study the Daphnia pulex species complex in particular, but no study has completed a wide-scale survey on the crustacean species that inhabit Churchill's aquatic ecosystems using molecular markers. We have employed DNA barcoding to study the diversity of the Branchiopoda (Crustacea) in a wide variety of freshwater habitats and to determine the likely origins of the Churchill fauna following the last glaciation. The standard animal barcode marker (COI) was sequenced for 327 specimens, and a 3% divergence threshold was used to delineate potential species. We found 42 provisional and valid branchiopod species from this survey alone, including several cryptic lineages, in comparison with the 25 previously recorded from previous ecological works. Using published sequence data, we explored the phylogeographic affinities of Churchill's branchiopods, finding that the Churchill fauna apparently originated from all directions from multiple glacial refugia (including southern, Beringian, and high arctic regions). Overall, these microcrustaceans are very diverse in Churchill and contain multiple species complexes. The present study introduces among the first sequences for some understudied genera, for which further work is required to delineate species boundaries and develop a more complete understanding of branchiopod diversity over a larger spatial scale

    Metabolic profiling detects early effects of environmental and lifestyle exposure to cadmium in a human population

    Get PDF
    Background: The ‘exposome’ represents the accumulation of all environmental exposures across a lifetime. Topdown strategies are required to assess something this comprehensive, and could transform our understanding of how environmental factors affect human health. Metabolic profiling (metabonomics/metabolomics) defines an individual’s metabolic phenotype, which is influenced by genotype, diet, lifestyle, health and xenobiotic exposure, and could also reveal intermediate biomarkers for disease risk that reflect adaptive response to exposure. We investigated changes in metabolism in volunteers living near a point source of environmental pollution: a closed zinc smelter with associated elevated levels of environmental cadmium. Methods: High-resolution 1H NMR spectroscopy (metabonomics) was used to acquire urinary metabolic profiles from 178 human volunteers. The spectral data were subjected to multivariate and univariate analysis to identify metabolites that were correlated with lifestyle or biological factors. Urinary levels of 8-oxo-deoxyguanosine were also measured, using mass spectrometry, as a marker of systemic oxidative stress. Results: Six urinary metabolites, either associated with mitochondrial metabolism (citrate, 3-hydroxyisovalerate, 4- deoxy-erythronic acid) or one-carbon metabolism (dimethylglycine, creatinine, creatine), were associated with cadmium exposure. In particular, citrate levels retained a significant correlation to urinary cadmium and smoking status after controlling for age and sex. Oxidative stress (as determined by urinary 8-oxo-deoxyguanosine levels) was elevated in individuals with high cadmium exposure, supporting the hypothesis that heavy metal accumulation was causing mitochondrial dysfunction. Conclusions: This study shows evidence that an NMR-based metabolic profiling study in an uncontrolled human population is capable of identifying intermediate biomarkers of response to toxicants at true environmental concentrations, paving the way for exposome research. Keywords: metabonomics, cadmium, environmental health, exposome, metabolomics, molecular epidemiolog

    A Genome-Wide Immunodetection Screen in S. cerevisiae Uncovers Novel Genes Involved in Lysosomal Vacuole Function and Morphology

    Get PDF
    Vacuoles of yeast Saccharomyces cerevisiae are functionally analogous to mammalian lysosomes. Both are cellular organelles responsible for macromolecular degradation, ion/pH homeostasis, and stress survival. We hypothesized that undefined gene functions remain at post-endosomal stage of vacuolar events and performed a genome-wide screen directed at such functions at the late endosome and vacuole interface – ENV genes. The immunodetection screen was designed to identify mutants that internally accumulate precursor form of the vacuolar hydrolase carboxypeptidase Y (CPY). Here, we report the uncovering and initial characterizations of twelve ENV genes. The small size of the collection and the lack of genes previously identified with vacuolar events are suggestive of the intended exclusive functional interface of the screen. Most notably, the collection includes four novel genes ENV7, ENV9, ENV10, and ENV11, and three genes previously linked to mitochondrial processes – MAM3, PCP1, PPE1. In all env mutants, vesicular trafficking stages were undisturbed in live cells as assessed by invertase and active α-factor secretion, as well as by localization of the endocytic fluorescent marker FM4-64 to the vacuole. Several mutants exhibit defects in stress survival functions associated with vacuoles. Confocal fluorescence microscopy revealed the collection to be significantly enriched in vacuolar morphologies suggestive of fusion and fission defects. These include the unique phenotype of lumenal vesicles within vacuoles in the novel env9Δ mutant and severely fragmented vacuoles upon deletion of GET4, a gene recently implicated in tail anchored membrane protein insertion. Thus, our results establish new gene functions in vacuolar function and morphology, and suggest a link between vacuolar and mitochondrial events
    corecore