57 research outputs found

    Structure of benthic communities in small rivers of southern Sakhalin in summer-autumn period, a case of the Lyutoga River tributaries

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    Quantitative characteristics of microbial community, algal periphyton and macrozoobenthos are presented for two tributaries of the Lyutoga River, as the Partizanka River (pink salmon spawning stream) and the Frikena River (without steady spawning grounds), on the base of surveys conducted in July-October, 2011. Number of benthic bacteria in the bottom grounds varied in the range 1.1-4.0 · 106 cells/g in the Frikena and 0.8-11.1 · 106 cells/g in the Partizanka. Oligocarbophilic microorganisms prevailed in the bacterial benthos of both rivers before the beginning of active salmon spawning (July- August), developing mainly on autochthonous organic substrates. In September, with appearance of salmon carcasses after spawning, total abundance of the microorganisms increased and the portion of ammonifying bacteria basing on this allochthonous organic matter became higher in the Partizanka. Algal periphyton biomass changed from 7.8 to 117.0 g/m2 in the Frikena River and from 0.5 to 305.6 g/m2 in the Partizanka River, with diatoms domination in both streams. Periphyton in the Partizanka was destroyed by flood in September but successively recovered by October, with multiple increasing of the algal biomass, obviously due to influx of nutrients in the process of salmon carcasses decomposing. Biomass of macrozoobenthos was 5.1-21.0 g/m2 in the Frikena River and 2.2 to 3.7 g/m2 in the Partizanka River, in both tributaries its dynamics was determined mainly by life cycles of aquatic insects

    Galactic Cosmic Rays from Superbubbles and the Abundances of Lithium, Beryllium, and Boron

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    In this article we study the galactic evolution of the LiBeB elements within the framework of a detailed model of the chemical evolution of the Galaxy that includes galactic cosmic ray nucleosynthesis by particles accelerated in superbubbles. The chemical composition of the superbubble consists of varying proportions of ISM and freshly supernova synthesized material. The observational trends of 6 LiBeB evolution are nicely reproduced by models in which GCR come from a mixture of 25% of supernova material with 75% of ISM, except for 6 Li, for which maybe an extra source is required at low metallicities. To account for 7 Li evolution several additional sources have been considered (neutrino-induced nucleosynthesis, nova outbursts, C-stars). The model fulfills the energetic requirements for GCR acceleration.Comment: 25 pages, 9 figures. Accepted for publication in the Astrophysical Journa

    Non-syndromic Hearing Impairment in a Hungarian Family with the m.7510T>C Mutation of Mitochondrial tRNA^^Ser(UCN)^^^ and Review of Published Cases

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    The m.7510T>C mitochondrial DNA (mtDNA) mutation is a tRNA(Ser(UCN)) alteration leading to matrilineal isolated hearing impairment. The current paper reviews the available reports on the m.7510T>C mtDNA mutation, with special attention to phenotypic variations and haplogroup background. A Hungarian family, the fourth family reported in the literature, is presented, in which analysis of three generations with bilateral isolated hearing loss revealed the m.7510T>C tRNA(Ser(UCN)) mutation in homoplasmic form in the affected members. Haplogroup analysis verified an unnamed subgroup of mitochondrial haplogroup H. Previously reported Spanish and North American Caucasian families belong to different subgroups of haplogroup H. Analyzing our biobank of Hungarian patients with sensorineural hearing loss, we did not detect this mutation in any other patient, nor was it found in Caucasian haplogroup H control samples. Comparing the cases reported so far, there is interfamilial variablity in the age of onset, accompanying symptoms, and haplogroup background. Our case adds further genetic evidence for the pathogenicity of the m.7510T>C mutation and underlines the need to include full mtDNA sequencing in the screening for unexplained hearing loss

    A wide spectrum of clinical and brain MRI findings in patients with SLC19A3 mutations

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    <p>Abstract</p> <p>Background</p> <p>SLC19A3 (solute carrier family 19, member 3) is a thiamin transporter with 12 transmembrane domains. Homozygous or compound heterozygous mutations in <it>SLC19A3 </it>cause two distinct clinical phenotypes, biotin-responsive basal ganglia disease and Wernicke's-like encephalopathy. Biotin and/or thiamin are effective therapies for both diseases.</p> <p>Methods</p> <p>We conducted on the detailed clinical, brain MRI and molecular genetic analysis of four Japanese patients in a Japanese pedigree who presented with epileptic spasms in early infancy, severe psychomotor retardation, and characteristic brain MRI findings of progressive brain atrophy and bilateral thalami and basal ganglia lesions.</p> <p>Results</p> <p>Genome-wide linkage analysis revealed a disease locus at chromosome 2q35-37, which enabled identification of the causative mutation in the gene <it>SLC19A3</it>. A pathogenic homozygous mutation (c.958G > C, [p.E320Q]) in <it>SLC19A3 </it>was identified in all four patients and their parents were heterozygous for the mutation. Administration of a high dose of biotin for one year improved neither the neurological symptoms nor the brain MRI findings in one patient.</p> <p>Conclusion</p> <p>Our cases broaden the phenotypic spectrum of disorders associated with <it>SLC19A3 </it>mutations and highlight the potential benefit of biotin and/or thiamin treatments and the need to assess the clinical efficacy of these treatments.</p

    Open data platforms and their usability: Proposing a framework for evaluating citizen intentions

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    Governments across the world are releasing public data in an effort to increase transparency of how public services are managed whilst also enticing citizens to participate in the policy decision-making processes. The channel for making open data available to citizens in the UK is the data.gov.uk platform, which brings together data relating to various public services in one searchable website. The data.gov.uk platform currently offers access to 25,500 datasets that are organized across key public service themes including health, transport, education, environment, and public spending in towns and cities. While the website reports 5,438,159 site visits as of June 2015, the average time spent on the site has been recorded at just 02:12 min per visitor. This raises questions regarding the actual use and usability of open data platforms and the extent to which they fulfill the stated outcomes of open data. In this paper, the authors examine usability issues surrounding open data platforms and propose a framework that can be used to evaluate their usability
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