8,445 research outputs found

    MgII absorption systems with W_0 > 0.1 \AA for a radio selected sample of 77 QSOs and their associated magnetic fields at high redshifts

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    We present a catalogue of MgII absorption systems obtained from high resolution UVES/VLT data of 77 QSOs in the redshift range 0.6 < z < 2.0, and down to an equivalent width W_0 > 0.1 \AA. The statistical properties of our sample are found to be in agreement with those from previous work in the literature. However, we point out that the previously observed increase with redshift of dN/dz for weak absorbers, pertains exclusively to very weak absorbers with W_0 < 0.1 \AA. Instead, dN/dz for absorbers with W_0 in the range 0.1-0.3 \AA actually decreases with redshift, similarly to the case of strong absorbers. We then use this catalogue to extend our earlier analysis of the links between the Faraday Rotation Measure of the quasars and the presence of intervening MgII absorbing systems in their spectra. In contrast to the case with strong MgII absorption systems W_0 > 0.3 \AA, the weaker systems do not contribute significantly to the observed Rotation Measure of the background quasars. This is possibly due to the higher impact parameters of the weak systems compared to strong ones, suggesting that the high column density magnetized material that is responsible for the Faraday Rotation is located within about 50 kpc of the galaxies. Finally, we show that this result also rules out the possibility that some unexpected secondary correlation between the quasar redshift and its intrinsic Rotation Measure is responsible for the association of high Rotation Measure and strong intervening MgII absorption that we have presented elsewhere, since this would have produced an equal effect for the weak absorption line systems, which exhibit a very similar distribution of quasar redshifts.Comment: Accepted for publication in ApJ. 12 pages, 8 figure

    Healing skills from the underserved patient perspective

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    Why overlearned sequences are special: distinct neural networks in the right hemisphere for ordinal sequences

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    Written and spoken words activate left hemisphere areas involved in language processing. However, we here show that overlearned sequences (e.g. letters, numbers, weekdays, months) involve an unexpected right hemispheric activation in both the middle temporal gyrus and temporoparietal junction. Our findings offer a framework for understanding neuropsychological patterns seen in conditions such as synesthesia, in which anomalous perceptual experiences are triggered by overlearned sequences, and also in semantic dementia, in which left hemisphere damage disrupts word knowledge even while sequences can be spared

    Thermal feedback in Si JFETs operating at low temperatures

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    Thermal feedback theory for silicon junction FET operating at low temperature

    Predictability engenders more efficient neural responses

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    The neural response to a stimulus diminishes with repeated presentations, a phenomenon known as repetition suppression. We here use neuroimaging to demonstrate that repetition suppression appears to be a special case of &#x22;prediction suppression&#x22;--that is, the brain shows diminishing activity when subsequent stimuli in a train are predictable. This demonstration supports the hypothesis that the brain dynamically leverages prediction to minimize energy consumption

    Measuring Sustainability

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    Planning for sustainability is high on many agendas, and tools to measure sustainability have been developed. Sustainable processes are those whose rates are maintained over time without exceeding the innate ability of its surroundings to support the process. We present the necessary conditions along with a new algorithm for measuring the sustainability of processes that integrates the laws of thermodynamics with laws for rate processes. The algorithm permits the assessment of the degree of sustainability of any process, whether ecological, economic, or social, as well as chemical or biological. It is a dynamic approach that applies at any scale and takes into consideration the spatial and temporal factors of processes, thus permitting empirical applications that correspond to real world (dynamic, complex, evolving) conditions across space and time. These characteristics make it especially suitable for applications in the field of spatial planning

    Mashing up Visual Languages and Web Mash-ups

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    Research on web mashups and visual languages share an interest in human-centered computing. Both research communities are concerned with supporting programming by everyday, technically inexpert users. Visual programming environments have been a focus for both communities, and we believe that there is much to be gained by further discussion between these research communities. In this paper we explore some connections between web mashups and visual languages, and try to identify what each might be able to learn from the other. Our goal is to establish a framework for a dialog between the communities, and to promote the exchange of ideas and our respective understandings of humancentered computing.published or submitted for publicationis peer reviewe
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