228 research outputs found

    Element Level Bridge Inspection: Benefits and Use of Data for Bridge Management

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    In 2012, Congress passed the Moving Ahead for Progress in the 21st Century Act (MAP-21) and committed to the development of a data-driven, risk based approach to asset management in the United States. This law requires the collection and submission of element level bridge inspection data for all National Highway System bridges, in addition to the National Bridge Inspection condition rating data. Ultimately, the data collected during element level bridge inspections should satisfy the requirements of the Federal Highway Administration and MAP-21 and be utilized by INDOT to evaluate bridge condition, predict deterioration, and guide decision making. The objective of this project is to develop recommendations for element level bridge inspection techniques, data collection, and inspector training based on a survey of INDOT peer agencies and a literature review of existing research and bridge inspection guidance. In order to collect consistent and reliable data, a rigorous inspector training program and detailed quality control procedures are necessary. INDOT must provide inspectors with the tools to be successful, including clearly defined expectations and instructions, comprehensive training and technical support, and effective inspection equipment. Similarly, robust quality control measures and periodic performance testing should be implemented to improve inspection quality and assess the agency’s performance

    Bias and Misrepresentation of Science Undermines Productive Discourse on Animal Welfare Policy: A Case Study

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    Reliable scientific knowledge is crucial for informing legislative, regulatory, and policy decisions in a variety of areas. To that end, scientific reviews of topical issues can be invaluable tools for informing productive discourse and decision-making, assuming these reviews represent the target body of scientific knowledge as completely, accurately, and objectively as possible. Unfortunately, not all reviews live up to this standard. As a case in point, Marino et al.’s review regarding the welfare of killer whales in captivity contains methodological flaws and misrepresentations of the scientific literature, including problematic referencing, overinterpretation of the data, misleading word choice, and biased argumentation. These errors and misrepresentations undermine the authors’ conclusions and make it impossible to determine the true state of knowledge of the relevant issues. To achieve the goal of properly informing public discourse and policy on this and other issues, it is imperative that scientists and science communicators strive for higher standards of analysis, argumentation, and objectivity, in order to clearly communicate what is known, what is not known, what conclusions are supported by the data, and where we are lacking the data necessary to draw reliable conclusions

    Negative Thermal Expansion Near the Precipice of Structural Stability in Open Perovskites

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    Negative thermal expansion (NTE) describes the anomalous propensity of materials to shrink when heated. Since its discovery, the NTE effect has been found in a wide variety of materials with an array of magnetic, electronic and structural properties. In some cases, the NTE originates from phase competition arising from the electronic or magnetic degrees of freedom but we here focus on a particular class of NTE which originates from intrinsic dynamical origins related to the lattice degrees of freedom, a property we term structural negative thermal expansion (SNTE). Here we review some select cases of NTE which strictly arise from anharmonic phonon dynamics, with a focus on open perovskite lattices. We find that NTE is often present close in proximity to competing structural phases, with structural phase transition lines terminating near T=0 K yielding the most prominent displays of the SNTE effect. We further provide a theoretical model to make precise the proposed relationship among the signature behavior of SNTE, the proximity of these systems to structural quantum phase transitions and the effects of phase fluctuations near these unique regions of the structural phase diagram. The effects of compositional disorder on NTE and structural phase stability in perovskites are discussed

    Growth and characterization of α\alpha-Sn thin films on In- and Sb-rich reconstructions of InSb(001)

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    α\alpha-Sn thin films can exhibit a variety of topologically non-trivial phases. Both studying the transitions between these phases and making use of these phases in eventual applications requires good control over the electronic and structural quality of α\alpha-Sn thin films. α\alpha-Sn growth on InSb often results in out-diffusion of indium, a p-type dopant. By growing α\alpha-Sn via molecular beam epitaxy on the Sb-rich c(4×\times4) surface reconstruction of InSb(001) rather than the In-rich c(8×\times2), we demonstrate a route to substantially decrease and minimize this indium incorporation. The reduction in indium concentration allows for the study of the surface and bulk Dirac nodes in α\alpha-Sn via angle-resolved photoelectron spectroscopy without the common approaches of bulk doping or surface dosing, simplifying topological phase identification. The lack of indium incorporation is verified in angle-resolved and -integrated ultraviolet photoelectron spectroscopy as well as in clear changes in the Hall response

    Validation of the Chronic Pain Acceptance Questionnaire-8 in an Australian pain clinic sample

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    Background: Recently, an 8-item short-form version of the Chronic Pain Acceptance Questionnaire (CPAQ-8) was developed predominantly in an internet sample. Further investigation of the factor structure in a multidisciplinary pain clinic sample is required. Investigation of the concurrent validity of the CPAQ-8 after accounting for the effects of variables commonly measured in the pain clinic setting is also necessary. Purpose: This study examines the factor structure and concurrent validity of the CPAQ-8 in a sample of treatmentseeking patients who attended a multidisciplinary pain clinic. Methods: Participants were 334 patients who attended an Australian multidisciplinary pain service. Participants completed the CPAQ, a demographic questionnaire, and measures of patient adjustment and functioning. Results: Confirmatory factor analysis identified a two-factor 8-item model consisting of Activity Engagement and Pain Willingness factors (SRMR=0.039, RMSEA=0.063, CFI=0.973, TLI=0.960) was superior to both the CPAQ and CPAQ with an item removed. The CPAQ and CPAQ-8 total scores were highly correlated (r=0.93). After accounting for pain intensity, the CPAQ-8 was a significant predictor of depression, anxiety, stress, and disability. The subscales of the CPAQ-8 were both unique contributors to depression and disability in regression analyses, after accounting for pain intensity and kinesiophobia, and after accounting for pain intensity and catastrophizing. Conclusions: The CPAQ-8 has a sound factor structure and similar psychometric properties to the CPAQ; it may have clinical utility as a measure of pain acceptance in treatmentseeking, chronic pain patients

    The unusual M-dwarf Warm Jupiter TOI-1899~b: Refinement of orbital and planetary parameters

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    TOI-1899~b is a rare exoplanet, a temperate Warm Jupiter orbiting an M-dwarf, first discovered by \citet{Canas2020_toi1899} from a TESS single-transit event. Using new radial velocities (RVs) from the precision RV spectrographs HPF and NEID, along with additional TESS photometry and ground-based transit follow-up, we are able to derive a much more precise orbital period of P=29.0903120.000035+0.000036P = 29.090312_{-0.000035}^{+0.000036}~d, along with a radius of Rp=0.99±0.03R_p = 0.99\pm0.03~\unit{R_{J}}. We have also improved the constraints on planet mass, Mp=0.67±0.04M_p = 0.67\pm{0.04}~\unit{M_{J}}, and eccentricity, which is consistent with a circular orbit at 2σ\sigma (e=0.0440.027+0.029e = 0.044_{-0.027}^{+0.029}). TOI-1899~b occupies a unique region of parameter space as the coolest known (TeqT_{eq} \approx 380~K) Jovian-sized transiting planet around an M-dwarf; we show that it has great potential to provide clues regarding the formation and migration mechanisms of these rare gas giants through transmission spectroscopy with JWST as well as studies of tidal evolution.Comment: 19 pages, 7 figures, 3 tables, submitted to AJ (comments welcome

    LSST: from Science Drivers to Reference Design and Anticipated Data Products

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    (Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg2^2 field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5σ\sigma point-source depth in a single visit in rr will be 24.5\sim 24.5 (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg2^2 with δ<+34.5\delta<+34.5^\circ, and will be imaged multiple times in six bands, ugrizyugrizy, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg2^2 region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to r27.5r\sim27.5. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overvie

    Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

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    Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

    The khmer software package: enabling efficient nucleotide sequence analysis [version 1; referees: 2 approved, 1 approved with reservations]

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    The khmer package is a freely available software library for working efficiently with fixed length DNA words, or k-mers. khmer provides implementations of a probabilistic k-mer counting data structure, a compressible De Bruijn graph representation, De Bruijn graph partitioning, and digital normalization. khmer is implemented in C++ and Python, and is freely available under the BSD license at https://github.com/dib-lab/khmer/

    The Marine Microbial Eukaryote Transcriptome Sequencing Project (MMETSP): illuminating the functional diversity of eukaryotic life in the oceans through transcriptome sequencing

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    International audienceCurrent sampling of genomic sequence data from eukaryotes is relatively poor, biased, and inadequate to address important questions about their biology, evolution, and ecology; this Community Page describes a resource of 700 transcriptomes from marine microbial eukaryotes to help understand their role in the world's oceans
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