1,043 research outputs found

    The idea of culture: Kant's boundary of reason as an imperative in the education of a modern person

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    The culturological twist in modern science and practical activities implies the clarification of the essence of culture. Turning to the history of the philosophical thought, it is possible to trace the transformation of the understanding of culture, the origins of the current discontinuity between the rational cognition and the life-purpose positions, which are discovered in the renaissance anthropocentrism and metaphysics of the practical reason of the Modern period. The article addresses the perspective of the Kantian interpretation of culture, which examines the reason with regard to its origin and highest maxims

    Impact of minority concentration on fundamental (H)D ICRF heating performance in JET-ILW

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    ITER will start its operation with non-activated hydrogen and helium plasmas at a reduced magnetic field of B-0 = 2.65 T. In hydrogen plasmas, the two ion cyclotron resonance frequency (ICRF) heating schemes available for central plasma heating (fundamental H majority and 2nd harmonic He-3 minority ICRF heating) are likely to suffer from relatively low RF wave absorption, as suggested by numerical modelling and confirmed by previous JET experiments conducted in conditions similar to those expected in ITER's initial phase. With He-4 plasmas, the commonly adopted fundamental H minority heating scheme will be used and its performance is expected to be much better. However, one important question that remains to be answered is whether increased levels of hydrogen (due to e. g. H pellet injection) jeopardize the high performance usually observed with this heating scheme, in particular in a full-metal environment. Recent JET experiments performed with the ITER-likewall shed some light onto this question and the main results concerning ICRF heating performance in L-mode discharges are summarized here

    Nuclear Fusion via Triple Collisions in Solar Plasma

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    We consider several nuclear fusion reactions that take place at the center of the sun, which are omitted in the standard pp-chain model. More specifically the reaction rates of the nonradiative production of ^3He, ^7Be, and ^8B nuclei in triple collisions involving electrons are estimated within the framework of the adiabatic approximation. These rates are compared with those of the corresponding binary fusion reactions.Comment: 3 pages, latex (RevTex), no figure

    Genetic variation in the oxytocin system and its link to social motivation in human infants

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    Frontal brain asymmetry has been linked to motivational processes in infants and adults, with left lateralization reflecting motivation to approach and right lateralization reflecting motivation to withdraw. We examined the hypothesis that variability in infants’ social motivation may be linked to genetic variation in the oxytocin system. Eleven-month-old infants’ brain responses and looking preferences to smiling and frowning individuals were assessed in conjunction with a polymorphism in CD38 (rs3796863) linked to autism spectrum disorder (ASD) and reduced oxytocin. Frontal brain asymmetry and looking preferences differed as a function of CD38 genotype. While non-risk A-allele carriers displayed left lateralization to smiling faces (approach) and a heightened looking preference for the individual who smiled, infants with the CC (ASD risk) genotype displayed withdrawal from smiling faces and a preference for the individual who frowned. Findings demonstrate that the oxytocin system is linked to brain and behavioral markers of social motivation in infancy

    Energetics of intrinsic defects and their complexes in ZnO investigated by density functional calculations

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    Formation energies of various intrinsic defects and defect complexes in ZnO have been calculated using a density-functional-theory-based pseudopotential all-electron method. The various defects considered are oxygen vacancy (VO), zinc vacancy (VZn), oxygen at an interstitial site (Oi), Zn at an interstitial site (Zni), Zn at VO (ZnO), O at VZn(OZn), and an antisite pair (combination of the preceding two defects). In addition, defect complexes like (VO+Zni) and Zn-vacancy clusters are studied. The Schokkty pair (VO+VZn) and Frenkel pairs [(VO+Oi) and (VZn+Zni)] are considered theoretically for the first time. Upon comparing the formation energies of these defects, we find that VO would be the dominant intrinsic defect under both Zn-rich and O-rich conditions and it is a deep double donor. Both ZnO and Zni are found to be shallow donors. The low formation energy of donor-type intrinsic defects could lead to difficulty in achieving p-type conductivity in ZnO. Defect complexes have charge transitions deep inside the band gap. The red, yellow, and green photoluminescence peaks of undoped samples can be assigned to some of the defect complexes considered. It is believed that the red luminescence originates from an electronic transition in VO, but we find that it can originate from the antisite ZnO defect. Charge density and electron-localization function analyses have been used to understand the effect of these defects on the ZnO lattice. The electronic structure of ZnO with intrinsic defects has been studied using density-of-states and electronic band structure plots. The acceptor levels introduced by VZn are relatively localized, making it difficult to achieve p-type conductivity with sufficient hole mobility.Peer reviewe

    Single-component near-infrared optogenetic systems for gene transcription regulation

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    Near-infrared (NIR) optogenetic systems for transcription regulation are in high demand because NIR light exhibits low phototoxicity, low scattering, and allows combining with probes of visible range. However, available NIR optogenetic systems consist of several protein components of large size and multidomain structure. Here, we engineer single-component NIR systems consisting of evolved photosensory core module of Idiomarina sp. bacterial phytochrome, named iLight, which are smaller and packable in adeno-associated virus. We characterize iLight in vitro and in gene transcription repression in bacterial and gene transcription activation in mammalian cells. Bacterial iLight system shows 115-fold repression of protein production. Comparing to multi-component NIR systems, mammalian iLight system exhibits higher activation of 65-fold in cells and faster 6-fold activation in deep tissues of mice. Neurons transduced with viral-encoded iLight system exhibit 50-fold induction of fluorescent reporter. NIR light-induced neuronal expression of green-light-activatable CheRiff channelrhodopsin causes 20-fold increase of photocurrent and demonstrates efficient spectral multiplexing. Current near-IR optogenetic systems to regulate transcription consist of a number of large protein components. Here the authors report a smaller single-component near-IR system, iLight, developed from a bacterial phytochrome that they use to control gene transcription in bacterial and mammalian cells.Peer reviewe
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