894 research outputs found

    A general-purpose microcontroller-based framework for integrating oceanographic sensors, instruments, and peripherals

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    Author Posting. © American Meteorological Society, 2017. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Atmospheric and Oceanic Technology 34 (2017): 415-427, doi:10.1175/JTECH-D-16-0069.1.Sensors and instruments for basic oceanographic properties are becoming increasingly sophisticated, which both simplifies and complicates their use in field studies. This increased sophistication disproportionately affects smaller-scale observational efforts that are less likely to be well supported technically but which need to integrate instruments, sensors, and commonly needed peripheral devices in ways not envisioned by their manufacturers. A general-purpose hardware and software framework was developed around a widely used family of low-power microcontrollers to lessen the technical expertise and customization required to integrate sensors, instruments, and peripherals, and thus simplify such integration scenarios. Both the hardware and associated firmware development tools provide a range of features often required in such scenarios: serial data interfaces, analog inputs and outputs, logic lines and power-switching capability, nonvolatile storage of data and parameters for sampling or configuration, and serial communication interfaces to supervisory or telemetry systems. The microcontroller and additional components needed to implement this integration framework are small enough to encapsulate in standard cable splices, creating a small form factor “smart cable” that can be readily wired and programmed for a range of integration needs. An application programming library developed for this hardware provides skeleton code for functions commonly desired when integrating sensors, instruments, and peripherals. This minimizes the firmware programming expertise needed to apply this framework in many integration scenarios and thus streamlines the development of firmware for different field applications. Envisioned applications are in field programs where significant technical instrumentation expertise is unavailable or not cost effective.Link Foundation Ocean Engineering graduate fellowship to SRL. Subsequent development effort was supported by a NASA New Investigator Award to SRL (NNX10AQ83G) and by the Woods Hole Oceanographic Institution through its Assistant Scientist Endowed Support, a Cecil H. and Ida M. Green Technology Innovation Award, and the Investment in Science Program

    Oral History Interview: Laney R. Wheeler

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    Mr. Wheeler of Coal Mountain, West Virginia, is a retired encyclopedia salesman. Born near Paintersville, Kentucky, he has lived most of his life in eastern Kentucky and southern West Virginia. Among the topics discussed are: family history, education, farm work, Mayo College in Paintsville, life in Matewan, Kentucky, and the Depression. Mr. Wheeler also talks about his work as a produce manager, pharmacist, and encyclopedia salesman.https://mds.marshall.edu/oral_history/1205/thumbnail.jp

    Theoretical Models for Classical Cepheids: IV. Mean Magnitudes and Colors and the Evaluation of Distance, Reddening and Metallicity

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    We discuss the metallicity effect on the theoretical visual and near-infrared PL and PLC relations of classical Cepheids, as based on nonlinear, nonlocal and time--dependent convective pulsating models at varying chemical composition. In view of the two usual methods of averaging (magnitude-weighted and intensity-weighted) observed magnitudes and colors over the full pulsation cycle, we briefly discuss the differences between static and mean quantities. We show that the behavior of the synthetic mean magnitudes and colors fully reproduces the observed trend of Galactic Cepheids, supporting the validity of the model predictions. In the second part of the paper we show how the estimate of the mean reddening and true distance modulus of a galaxy from Cepheid VK photometry depend on the adopted metal content, in the sense that larger metallicities drive the host galaxy to lower extinctions and distances. Conversely, self-consistent estimates of the Cepheid mean reddening, distance and metallicity may be derived if three-filter data are taken into account. By applying the theoretical PL and PLC relations to available BVK data of Cepheids in the Magellanic Clouds we eventually obtain Z \sim 0.008, E(B-V) \sim 0.02 mag, DM \sim 18.63 mag for LMC and Z \sim 0.004, E(B-V) \sim 0.01 mag., DM \sim 19.16 mag. for SMC. The discrepancy between such reddenings and the current values based on BVI data is briefly discussed.Comment: 16 pages, 11 postscript figures, accepted for publication on Ap

    Smart Cities and M<sup>3</sup>: Rapid Research, Meaningful Metrics and Co-Design

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    The research described in this paper is undertaken under the banner of the smart city, a concept that captures the way urban spaces are re-made by the incursion of new technology. Much of smart is centred on converting everyday activities into data, and using this data to generate knowledge mediated by technology. Ordinary citizens, those that may have their lives impacted by the technology, usually are not properly involved in the ‘smartification’ process. Their perceptions, concerns and expectations should inform the conception and development of smart technologies at the same extent. How to engage general public with smart cities research is the central challenge for the Making Metrics Meaningful (MMM) project. Applying a rapid participatory method, ‘Imagine’ over a five-month period (March – July) the research sought to gain insights from the general public into novel forms of information system innovation. This brief paper describes the nature of the accelerated research undertaken and explores some of the themes which emerged in the analysis. Generic themes, beyond the remit of an explicit transport focus, are developed and pointers towards further research directions are discussed. Participatory methods, including engaging with self- selected transport users actively through both picture creation and programmatically specific musical ‘signatures’ as well as group discussion, were found to be effective in eliciting users’ own concerns, needs and ideas for novel information systems

    The Shape and Scale of Galactic Rotation from Cepheid Kinematics

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    A catalog of Cepheid variables is used to probe the kinematics of the Galactic disk. Radial velocities are measured for eight distant Cepheids toward l = 300; these new Cepheids provide a particularly good constraint on the distance to the Galactic center, R_0. We model the disk with both an axisymmetric rotation curve and one with a weak elliptical component, and find evidence for an ellipticity of 0.043 +/- 0.016 near the Sun. Using these models, we derive R_0 = 7.66 +/- 0.32 kpc and v_circ = 237 +/- 12 km/s. The distance to the Galactic center agrees well with recent determinations from the distribution of RR Lyrae variables, and disfavors most models with large ellipticities at the solar orbit.Comment: 36 pages, LaTeX, 10 figure

    The accuracy of a point-of-care test among different operators using the QBC Autoread Plus Analyzer for the measurement of a basic full blood count

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    Background. Major issues around the implementation of point-of-care testing (POCT) include: user type, regulatory control, ongoing quality monitoring and limited guideline adherence.59 December 2019, Print editionObjectives. To determine if there are significant differences in the results of a POC full blood count test between different levels of healthcare and non-medical ‘lay’ users compared with laboratory users (technologists/pathologists).Methods. This article retrospectively reviews the technical evaluation database of the intensive care unit (ICU), Chris Hani Baragwanath Academic Hospital, Johannesburg, South Africa. We searched for samples analysed by doctors, clerks and laboratory personnel. A minimum number of 60 comparisons were required. Bland-Altman plots, Spearman’s correlation and Passing-Bablok fit were used to analyse the dataset.Results. There were 72 comparisons for haematocrit (Hct), 98 for white cell count (WCC) and 137 for platelets (Plt) between the clerk and laboratory personnel. The correlations were 0.91, 0.96 and 0.92, respectively. All were statistically significant. Using the Bland-Altman method, there was good agreement between results of the clerk and those of the laboratory staff, with a mean bias of 0.5% (Hct), 0.1 × 109/L (WCC) and 10 × 109/L (Plt). An insufficient number of tests were performed by medical doctors for statistical comparison.Conclusions. With appropriate training, non-medical, non-healthcare lay users are able to perform a moderately complex POCT with similar accuracy as trained laboratory professionals. The focus should shift to equipment and quality management processes rather than the medical/technical qualification of the user

    Learning Musical Contour on a Tabletop

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    Many successful tabletop applications for music making have been developed, and the technology has been investigated from different perspectives. Yet, to date, despite optimistic claims regarding their potential as learning tools, their role in helping people to explore, acquire, and rea- son about musical concepts has been sparsely researched. We have developed an exploratory study around a simple tabletop application that allows people to make music using a visual representation of melodic contour. Our aim is to understand whether and how such system might help peo- ple to reason about music in terms of contour while at the same time affording an enjoyable music making experience to musically untrained people. Our findings suggest that the system has potential as a learning tool, especially for beginners, but tutoring is still necessary to acquire, use, and express concepts precisely

    The cellular and molecular carcinogenic effects of radon exposure: a review.

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    Journal ArticleResearch Support, Non-U.S. Gov'tReviewOpen access articleRadon-222 is a naturally occurring radioactive gas that is responsible for approximately half of the human annual background radiation exposure globally. Chronic exposure to radon and its decay products is estimated to be the second leading cause of lung cancer behind smoking, and links to other forms of neoplasms have been postulated. Ionizing radiation emitted during the radioactive decay of radon and its progeny can induce a variety of cytogenetic effects that can be biologically damaging and result in an increased risk of carcinogenesis. Suggested effects produced as a result of alpha particle exposure from radon include mutations, chromosome aberrations, generation of reactive oxygen species, modification of the cell cycle, up or down regulation of cytokines and the increased production of proteins associated with cell-cycle regulation and carcinogenesis. A number of potential biomarkers of exposure, including translocations at codon 249 of TP53 in addition to HPRT mutations, have been suggested although, in conclusion, the evidence for such hotspots is insufficient. There is also substantial evidence of bystander effects, which may provide complications when calculating risk estimates as a result of exposure, particularly at low doses where cellular responses often appear to deviate from the linear, no-threshold hypothesis. At low doses, effects may also be dependent on cellular conditions as opposed to dose. The cellular and molecular carcinogenic effects of radon exposure have been observed to be both numerous and complex and the elevated chronic exposure of man may therefore pose a significant public health risk that may extend beyond the association with lung carcinogenesis

    Cepheid Period-Radius and Period-Luminosity Relations and the Distance to the LMC

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    We have used the infrared Barnes-Evans surface brightness technique to derive the radii and distances of 34 Galactic Cepheid variables. Radius and distance results obtained from both versions of the technique are in excellent agreement. The radii of 28 variables are used to determine the period-radius relation. This relation is found to have a smaller dispersion than in previous studies, and is identical to the period-radius relation found by Laney & Stobie from a completely independent method, a fact which provides persuasive evidence that the Cepheid period-radius relation is now determined at a very high confidence level. We use the accurate infrared distances to determine period-luminosity relations in the V, I, J, H and K passbands from the Galactic sample of Cepheids. We derive improved slopes of these relations from updated LMC Cepheid samples and adopt these slopes to obtain accurate absolute calibrations of the PL relation. By comparing these relations to the ones defined by the LMC Cepheids, we derive strikingly consistent and precise values for the LMC distance modulus in each of the passbands which yield a mean value of DM (LMC) = 18.46 +- 0.02. Our results show that the infrared Barnes-Evans technique is very insensitive to both Cepheid metallicity and adopted reddening, and therefore a very powerful tool to derive accurate distances to nearby galaxies by a direct application of the technique to their Cepheid variables, rather than by comparing PL relations of different galaxies, which introduces much more sensitivity to metallicity and absorption corrections which are usually difficult to determine.Comment: LaTeX, AASTeX style, 9 Figures, 10 Tables, The Astrophysical Journal in press (accepted Oct. 14, 1997). Fig. 3 replace

    The euphotic zone under Arctic Ocean sea ice : vertical extents and seasonal trends

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    © The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Limnology and Oceanography 62 (2017): 1910–1934, doi:10.1002/lno.10543.Eight Ice-Tethered Profilers were deployed in the Arctic Ocean between 2011 and 2013 to measure vertical distributions of photosynthetically active radiation (PAR) and other bio-optical properties in ice-covered water columns, multiple times a day over periods of up to a year. With the radiometers used on these profilers, PAR could be measured to depths of only ∼20–40 m in the central Arctic in late summer under sea ice ∼1 m thick. At lower latitudes in the Beaufort Gyre, late summer PAR was measurable under ice to depths exceeding 125 m. The maximum depths of measurable PAR followed seasonal trends in insolation, with isolumes shoaling in the fall as solar elevation decreased and deepening in spring and early summer after insolation resumed and sea ice diminished. PAR intensities were often anomalously low above 20 m, likely due to a shading effect associated with local horizontal heterogeneity in light transmittance by the overlying sea ice. A model was developed to parameterize these complex vertical PAR distributions to improve estimates of the water column diffuse attenuation coefficient and other related parameters. Such a model is necessary to separate the effect of surface ice heterogeneity on under-ice PAR profiles from that of the water column itself, so that euphotic zone depth in ice-covered water columns can be computed using canonical metrics such as the 1% light level. Water column diffuse attenuation coefficients derived from such autonomously-collected PAR profile data, using this model, agreed favorably with values determined manually in complementary studies.Woods Hole Oceanographic Institution; National Science Foundation Grant Number: ARC-085647
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