1,388 research outputs found

    Evolution of Cluster Ellipticals at 0.2 < z < 1.2 from Hubble Space Telescope Imaging

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    Two-dimensional surface photometry derived from Hubble Space Telescope imaging is presented for a sample of 225 early-type galaxies (assumed to be cluster members) in the fields of 9 clusters at redshifts 0.17<z<1.210.17 < z < 1.21. The 94 luminous ellipticals (MAB(B)<−20M_{AB}(B)<-20; selected by morphology alone with no reference to color) form tight sequences in the size-luminosity plane. The position of these sequences shifts, on average, with redshift so that an object of a given size at z=0.55 is brighter by ΔM(B)=−0.57±0.13\Delta M(B)=-0.57 \pm 0.13 mag than its counterpart (measured with the same techniques) in nearby clusters. At z=0.9 the shift is ΔM(B)=−0.96±0.22\Delta M(B)=-0.96 \pm 0.22 mag. If the relation between size and luminosity is universal so that the local cluster galaxies represent the evolutionary endpoints of those at high redshift, and if the size-luminosity relation is not modified by dynamical processes then this population of galaxies has undergone significant luminosity evolution since z=1 consistent with expectations based on models of passively evolving, old stellar populations.Comment: 7 pages, 3 figures, and 1 Tabl

    Semantic analysis of citizen sensing, crowdsourcing and VGI

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    This paper describes a semantic analysis of terms used to describe citizen sensing and crowdsourced data use in scientific analyses. It applies a latency analysis to journal abstracts downloaded from Scopus that matched one of number of terms related to crowd sourced data and citizen science. The latency analysis shows how the terms associated with crowdsourcing are related and how they have evolved over time.JRC.H.6-Digital Earth and Reference Dat

    Rapid growth of an intact human liver transplanted into a recipient larger than the donor

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    Two individuals undergoing orthotopic hepatic transplantation received livers from donors who were on average 10 kg smaller than themselves based on recipient ideal body weight. As a result, the donor livers in these 2 cases were 29%-59% smaller than would be expected had the donor liver and recipient been matched ideally. The liver grafts in the recipients steadily increased in size, as determined by serial computed tomography scanning, to achieve new volumes consistent with those that would have been expected in a normal individual of the recipient's size, sex, and age. Fasting plasma levels of amino acids, glucagon, insulin, and standard liver injury tests were monitored to determine which measure best reflected the changes observed in the size of the grafts over time. No relationship between the changes observed in any of these parameters and hepatic growth was apparent. In both cases, the liver increased in volume at a rate of ~70 ml/day. These data demonstrate that a small-for-size liver transplanted into a larger recipient increases in size at a rate of ~70 ml/day until it achieves a liver volume consistent with that expected given the recipient's size, age, and sex. © 1987

    Isomeric Xylene Molecules in the Terahertz Far Infrared Regime Computational Chemistry and Spectral Modeling View

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    The theoretical assignments of spectral peaks of liquid phase ortho , meta , and para xylene recorded with far infrared FIR and THz spectroscopy in the spectral range between 550 and 50 cm amp; 8722;1 is done with density functional theory DFT calculations. As THz spectroscopic techniques drastically evolved in recent years, the critical focus of this paper lies on the applicability of theoretical concepts, used as computational standard in near and mid IR spectra, to the FIR THz region. An evaluation of the choice of functionals, basis sets, and appropriate scaling factors as well as the tractability of the liquid phase in a polarizable continuum model is performed. Alongside a new analysis procedure based on spectral Hard Modeling has been developed. DFT line spectra are fitted to experimental FIR spectra where a quantitative track record allows for meaningful comparisons. With all these tools we are able to reproduce experimental spectra in an optically appealing way and we can explain trends for each spectrum as well as across the row of the isomer

    All hormone-producing cell types of the pituitary intermediate and anterior lobes derive from prop1-expressing progenitors

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    Mutations in PROP1, the most common known cause of combined pituitary hormone deficiency in humans, can result in the progressive loss of all hormones of the pituitary anterior lobe. In mice, Prop1 mutations result in the failure to initiate transcription of Pou1f1 (also known as Pit1) and lack somatotropins, lactotropins, and thyrotropins. The basis for this species difference is unknown. We hypothesized that Prop1 is expressed in a progenitor cell that can develop into all anterior lobe cell types, and not just the somatotropes, thyrotropes, and lactotropes, which are collectively known as the PIT1 lineage. To test this idea, we produced a transgenic Prop1-cre mouse line and conducted lineage-tracing experiments of Prop1-expressing cells. The results reveal that all hormone-secreting cell types of both the anterior and intermediate lobes are descended from Prop1-expressing progenitors. The Prop1-cre mice also provide a valuable genetic reagent with a unique spatial and temporal expression for generating tissue-specific gene rearrangements early in pituitary gland development. We also determined that the minimal essential sequences for reliable Prop1 expression lie within 10 kilobases of the mouse gene and demonstrated that human PROP1 can substitute functionally for mouse Prop1. These studies enhance our understanding of the pathophysiology of disease in patients with PROP1 mutations.Fil: Davis, Shannon W.. University of South Carolina; Estados UnidosFil: Keisler, Jessica L.. University of South Carolina; Estados UnidosFil: Pérez Millán, María Inés. University of Michigan; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Schade, Vanessa. University of Michigan; Estados UnidosFil: Camper, Sally A.. University of Michigan; Estados Unido

    Half adder capabilities of a coupled quantum dot device

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    We gratefully acknowledge nancial support from the European Union (FPVII, 2007- 2013) under grant agreement no 256959 NANOPOWER and grant agreement no 318287 LANDAUER as well as from the state of Bavaria.In this paper we demonstrate two realizations of a half adder based on a voltage-rectifying mechanism involving two Coulomb-coupled quantum dots. First, we examine the ranges of operation of the half adder's individual elements, the AND and XOR gates, for a single rectifying device. It allows a switching between the two gates by a control voltage and thus enables a clocked half adder operation. The logic gates are shown to be reliably operative in a broad noise amplitude range with negligible error probabilities. Subsequently, we study the implementation of the half adder in a combined double-device consisting of two individually tunable rectifiers. We show that this double device allows a simultaneous operation of both relevant gates at once. The presented devices draw their power solely from electronic fluctuations and are therefore an advancement in the field of energy efficient and autonomous electronics.PostprintPeer reviewe

    Examining the effects of Lighting Effects on Peripheral Devices for Visual User Notifications

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    The ubiquitous and pervasive use of lighting effects embedded into peripheral hardware has gained popularity through it’s use in Triple-A video game titles such as Call of Duty and the availability of software development kits (SDK) from leading manufacturers. A preliminary NASA TLX experiment was performed to examine the effect that notifications displayed on a peripheral device has, in comparison to traditional dialog notifications. This research will prove useful to create notification design guidance for these devices
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