1,268 research outputs found

    A limited speech recognition system 2 Final report

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    Limited speech recognition system for computer voice lin

    Appearance of the Single Gyroid Network Phase in Nuclear Pasta Matter

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    Nuclear matter under the conditions of a supernova explosion unfolds into a rich variety of spatially structured phases, called nuclear pasta. We investigate the role of periodic network-like structures with negatively curved interfaces in nuclear pasta structures, by static and dynamic Hartree-Fock simulations in periodic lattices. As the most prominent result, we identify for the first time the {\it single gyroid} network structure of cubic chiral I4123I4_123 symmetry, a well known configuration in nanostructured soft-matter systems, both as a dynamical state and as a cooled static solution. Single gyroid structures form spontaneously in the course of the dynamical simulations. Most of them are isomeric states. The very small energy differences to the ground state indicate its relevance for structures in nuclear pasta.Comment: 7 pages, 4 figure

    A limited speech recognition system Final report

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    Systems analysis, recognition algorithm, and design of limited speech recognition syste

    Possible link between Earth's rotation rate and oxygenation

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    The biotic and abiotic controls on major shifts in atmospheric oxygen and the persistence of low-oxygen periods over a majority of Earth’s history remain under debate. Explanations of Earth’s stepwise pattern of oxygenation have mostly neglected the effect of changing diel illumination dynamics linked to daylength, which has increased through geological time due to Earth’s rotational deceleration caused by tidal friction. Here we used microsensor measurements and dynamic modelling of interfacial solute fluxes in cyanobacterial mats to investigate the effect of changing daylength on Precambrian benthic ecosystems. Simulated increases in daylength across Earth’s historical range boosted the diel benthic oxygen export, even when the gross photosynthetic production remained constant. This fundamental relationship between net productivity and daylength emerges from the interaction of diffusive mass transfer and diel illumination dynamics, and is amplified by metabolic regulation and microbial behaviour. We found that the resultant daylength-driven surplus organic carbon burial could have shaped the increase in atmospheric oxygen that occurred during the Great and Neoproterozoic Oxidation Events. Our suggested mechanism, which links the coinciding increases in daylength and atmospheric oxygen via enhanced net productivity, reveals a possible contribution of planetary mechanics to the evolution of Earth’s biology and geochemistry

    Superconducting Superstructure for the TESLA Collider

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    We discuss the new layout of a cavity chain (superstructure) allowing, we hope, significant cost reduction of the RF system of both linacs of the TESLA linear collider. The proposed scheme increases the fill factor and thus makes an effective gradient of an accelerator higher. We present mainly computations we have performed up to now and which encouraged us to order the copper model of the scheme, still keeping in mind that experiments with a beam will be necessary to prove if the proposed solution can be used for the acceleration.Comment: 11 page

    Политехники - крупные военачальники

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    Differential Transgene Silencing of Myeloid-Specific Promoters in the AAVS1 Safe Harbor Locus of Induced Pluripotent Stem Cell-Derived Myeloid Cells

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    Targeted integration into a genomic safe harbor, such as the AAVS1 locus on chromosome 19, promises predictable transgene expression and reduces the risk of insertional mutagenesis in the host genome. The application of gamma-retroviral LTR-driven vectors, which semi-randomly integrate into the genome, has previously caused severe adverse events in some clinical studies due to transactivation of neighboring proto-oncogenes. Consequently, the site-specific integration of a therapeutic transgene into a genomic safe harbor locus would allow stable genetic correction with a reduced risk of insertional mutagenesis. However, recent studies revealed that transgene silencing, especially in case of weaker cell type-specific promoters, can occur in the AAVS1 locus of human pluripotent stem cells (PSC) and can impede transgene expression during differentiation. In this study, we aimed to correct p47phox-deficiency, which is the second most common cause of chronic granulomatous disease, by insertion of a therapeutic p47phox transgene into the AAVS1 locus of human induced PSC (iPSC) using CRISPR-Cas9. We analyzed transgene expression and functional correction from three different myeloid-specific promoters (miR223, CatG/cFes and MRP8). Upon myeloid differentiation of corrected iPSC clones, we observed that the miR223 and CatG/cFes promoter achieved therapeutic-relevant levels of p47phox expression and NADPH oxidase activity, whereas the MRP8 promoter was less efficient. Analysis of the different promoters revealed high CpG methylation of the MRP8 promoter in differentiated cells, which correlated with the transgene expression data. In summary, we identified the miR223 and CatG/cFes promoters as cell type-specific promoters that allow stable transgene expression in the AAVS1 locus of iPSC-derived myeloid cells. Our findings further indicate that promoter silencing can occur in the AAVS1 safe harbor locus in differentiated hematopoietic cells and that a comparison of different promoters is necessary to achieve optimal transgene expression for therapeutic application of iPSC-derived cells

    Iron Homeostasis in Yellowstone National Park Hot Spring Microbial Communities

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    It has been postulated that life may have originated on Earth, and possibly on Mars, in association with hydrothermal activity and high concentrations of ferrous iron. However, it is not clear how an iron-rich thermal hydrosphere could be hospitable to microbes, since reduced iron appears to stimulate oxidative stress in all domains of life and particularly in oxygenic phototrophs. Therefore, the study of microbial diversity in iron-depositing hot springs (IDHS) and the mechanisms of iron homeostasis and suppression of oxidative stress may help elucidate how Precambrian organisms could withstand the extremely high concentrations of reactive oxygen species (ROS) produced by interaction between environmental Fe(2+) and O2. Proteins and clusters of orthologous groups (COGs) involved in the maintenance of Fe homeostasis found in cyanobacteria (CB) inhabiting environments with high and low [Fe] were main target of this analysis. Preliminary results of the analysis suggest that the Chocolate Pots (CP) microbial community is heavily dominated by phototrophs from the cyanobacteria (CB), Chloroflexi and Chlorobi phyla, while the Mushroom Spring (MS) effluent channel harbors a more diverse community in which Chloroflexi are the dominant phototrophs. It is speculated that CB inhabiting IDHS have an increased tolerance to both high concentrations of Fe(2+) and ROS produced in the Fenton reaction. This hypothesis was explored via a comparative analysis of the diversity of proteins and COGs involved in Fe and redox homeostasis in the CP and MS microbiomes

    Finite temperature pasta matter with the TDHF approximation

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