2,836 research outputs found

    Regret Aversion and False Reference Points in Residential Real Estate

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    This study empirically exams the combination of regret aversion and false reference points in a residential real estate context. Survey respondents were put in a hypothetical situation, where they had purchased an investment property several years ago. Hindsight knowledge about a foregone all time high was introduced. As hypothesized, respondents on average expressed higher regret if they had actively failed to sell at the all time high (commission scenario) than if they had simply been unaware of the potential gain (omission scenario). Women were found to be more susceptible to regret aversion and false reference points than men.

    Atmospheric Biomarkers and their Evolution over Geological Timescales

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    The search for life on extrasolar planets is based on the assumption that one can screen extrasolar planets for habitability spectroscopically. The first space born instruments able to detect as well as characterize extrasolar planets, Darwin and terrestrial planet finder (TPF-I and TPF-C) are scheduled to launch before the end of the next decade. The composition of the planetary surface, atmosphere, and its temperature-pressure profile influence a detectable spectroscopic signal considerably. For future space-based missions it will be crucial to know this influence to interpret the observed signals and detect signatures of life in remotely observed atmospheres. We give an overview of biomarkers in the visible and IR range, corresponding to the TPF-C and TPF-I/DARWIN concepts, respectively. We also give an overview of the evolution of biomarkers over time and its implication for the search for life on extrasolar Earth-like planets. We show that atmospheric features on Earth can provide clues of biological activities for at least 2 billion years.Comment: for high resolution images see http://cfa-www.harvard.edu/~lkaltenegge

    Dynamically-Coupled Oscillators -- Cooperative Behavior via Dynamical Interaction --

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    We propose a theoretical framework to study the cooperative behavior of dynamically coupled oscillators (DCOs) that possess dynamical interactions. Then, to understand synchronization phenomena in networks of interneurons which possess inhibitory interactions, we propose a DCO model with dynamics of interactions that tend to cause 180-degree phase lags. Employing an approach developed here, we demonstrate that although our model displays synchronization at high frequencies, it does not exhibit synchronization at low frequencies because this dynamical interaction does not cause a phase lag sufficiently large to cancel the effect of the inhibition. We interpret the disappearance of synchronization in our model with decreasing frequency as describing the breakdown of synchronization in the interneuron network of the CA1 area below the critical frequency of 20 Hz.Comment: 10 pages, 3 figure

    The A20 Protein Interacts with the Epstein–Barr Virus Latent Membrane Protein 1 (LMP1) and Alters the LMP1/TRAF1/TRADD Complex

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    The Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) interacts with the tumor necrosis factor receptor (TNFR)-associated factor (TRAF) molecules, which are important for LMP1-mediated signaling. Two domains of LMP1 can independently activate NF-kB, carboxyl-terminal activating region 1 (CTAR1) and CTAR2. The activation of NF-kB by CTAR1 occurs through direct interaction of LMP1 with the TRAF molecules, whereas CTAR2 interacts with the TNFR-associated death domain protein (TRADD) to activate NF-kB and the c-Jun N-terminal kinase (JNK). A20, which is induced by LMP1 through NF-kB, can block NF-kB activation from both domains of LMP1 and inhibit JNK activation from CTAR2. A20 also has been shown to associate with TRAF1 and TRAF2. In this study, an interaction between LMP1 and A20 was detected that was increased by TRAF2 overexpression. A20 did not affect the association of TRAF1 with TRAF2 but did displace TRAF1 from the LMP1 complex. The interaction of LMP1 and TRADD was decreased in the presence of A20, and the LMP1-A20 association was decreased by TRADD, suggesting that A20 and TRADD both interact with LMP1 and may compete for binding. These data indicate that A20 alters the interactions between LMP1 and the TRAF molecules and TRADD, affecting the activation of NF-kB, JNK, and perhaps other TRAF-mediated signaling events

    First Keck Nulling Observations of a Young Stellar Object: Probing the Circumstellar Environment of the Herbig Ae star MWC 325

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    We present the first N-band nulling plus K- and L-band V2 observations of a young stellar object, MWC325, taken with the 85 m baseline Keck Interferometer. The Keck nuller was designed for the study of faint dust signatures associated with debris disks, but it also has a unique capability for studying the temperature and density distribution of denser disks found around young stellar objects. Interferometric observations of MWC 325 at K, L and N encompass a factor of five in spectral range and thus, especially when spectrally dispersed within each band, enable characterization of the structure of the inner disk regions where planets form. Fitting our observations with geometric models such as a uniform disk or a Gaussian disk show that the apparent size increases monotonically with wavelength in the 2-12 um wavelength region, confirming the widely held assumption based on radiative transfer models, now with spatially resolved measurements over broad wavelength range, that disks are extended with a temperature gradient. The effective size is a factor of about 1.3 and 2 larger in the L-band and N-band, respectively, compared to that in the K-band. The existing interferometric measurements and the spectral energy distribution can be reproduced by a flat disk or a weakly-shadowed nearly flat-disk model, with only slight flaring in the outer regions of the disk, consisting of representative "sub-micron" (0.1 um) and "micron" (2 um) grains of a 50:50 ratio of silicate and graphite. This is marked contrast with the disks previously found in other Herbig Ae/Be stars suggesting a wide variety in the disk properties among Herbig Ae/Be stars.Comment: Accepted for publication in the Ap

    Impact Analysis of OCR Quality on Research Tasks in Digital Archives

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    Humanities scholars increasingly rely on digital archives for their research in place of time-consuming visits to physical archives. This shift in research methodology has the hidden cost of working with digi- tally processed historical documents: how much trust can a scholar place in noisy representations of source texts? In a series of interviews with historians about their use of digital archives, we found that scholars are aware that optical character recognition (OCR) errors may bias their results. They were, however, unable to quantify this bias or to indicate what information they would need to estimate it. Based on the interviews and a literature study, we provide a classification scheme relating schol- arly research tasks to their specific OCR-induced uncertainty and the data required for more reliable uncertainty estimations. We conducted a use case study on a national newspaper archive with example research tasks. From this we learned what data is typically available in digital archives and how it could be used to reduce and/or assess the uncer- tainty in result sets. We conclude that the current knowledge situation on the users’ side as well as on the tool makers and data providers’ side is insufficient and needs further research to be improved

    Second Screen Interactions for Automatically Web-Enriched Broadcast Video

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    Including hypermedia in broadcast video combines content formatted for a lean-forward medium (the Web) with a lean-back one (TV) to form a hybrid medium. We identify four challenges for interacting with and experiencing this new medium. We discuss the role a second screen may play in addressing these challenges

    The prevalence of visual anomalies among adult offenders

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    Fifty-three incarcerated adult sexual offenders from a voluntary treatment program at the Oregon State Correctional Facility were screened for visual anomalies. Subjects were divided into two groups based on intellectual function, one a higher functioning (HF) group, and one a social skills (SS) group. The two groups were compared based on a screening battery probing ocular health, eye movement skills, visual perceptual abilities and accommodative/vergence abilities. The ocular health did not differ between the two groups or from the general population. Differences were found in visual perceptual function between the high and low functioning groups. The HF group outperformed the lower on all perceptual and eye movement tests except the subjective eye movement evaluation. Unexpected differences were found between the two groups in the areas of accommodative posture, vergence facility, and distance monocular acuities

    Imaging the spotty surface of Betelgeuse in the H band

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    This paper reports on H-band interferometric observations of Betelgeuse made at the three-telescope interferometer IOTA. We image Betelgeuse and its asymmetries to understand the spatial variation of the photosphere, including its diameter, limb darkening, effective temperature, surrounding brightness, and bright (or dark) star spots. We used different theoretical simulations of the photosphere and dusty environment to model the visibility data. We made images with parametric modeling and two image reconstruction algorithms: MIRA and WISARD. We measure an average limb-darkened diameter of 44.28 +/- 0.15 mas with linear and quadratic models and a Rosseland diameter of 45.03 +/- 0.12 mas with a MARCS model. These measurements lead us to derive an updated effective temperature of 3600 +/- 66 K. We detect a fully-resolved environment to which the silicate dust shell is likely to contribute. By using two imaging reconstruction algorithms, we unveiled two bright spots on the surface of Betelgeuse. One spot has a diameter of about 11 mas and accounts for about 8.5% of the total flux. The second one is unresolved (diameter < 9 mas) with 4.5% of the total flux. Resolved images of Betelgeuse in the H band are asymmetric at the level of a few percent. The MOLsphere is not detected in this wavelength range. The amount of measured limb-darkening is in good agreement with model predictions. The two spots imaged at the surface of the star are potential signatures of convective cells.Comment: 10 pages, 10 figures, accepted for publication in A&A, references adde
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