3,581 research outputs found
Viewpoints: A high-performance high-dimensional exploratory data analysis tool
Scientific data sets continue to increase in both size and complexity. In the
past, dedicated graphics systems at supercomputing centers were required to
visualize large data sets, but as the price of commodity graphics hardware has
dropped and its capability has increased, it is now possible, in principle, to
view large complex data sets on a single workstation. To do this in practice,
an investigator will need software that is written to take advantage of the
relevant graphics hardware. The Viewpoints visualization package described
herein is an example of such software. Viewpoints is an interactive tool for
exploratory visual analysis of large, high-dimensional (multivariate) data. It
leverages the capabilities of modern graphics boards (GPUs) to run on a single
workstation or laptop. Viewpoints is minimalist: it attempts to do a small set
of useful things very well (or at least very quickly) in comparison with
similar packages today. Its basic feature set includes linked scatter plots
with brushing, dynamic histograms, normalization and outlier detection/removal.
Viewpoints was originally designed for astrophysicists, but it has since been
used in a variety of fields that range from astronomy, quantum chemistry, fluid
dynamics, machine learning, bioinformatics, and finance to information
technology server log mining. In this article, we describe the Viewpoints
package and show examples of its usage.Comment: 18 pages, 3 figures, PASP in press, this version corresponds more
closely to that to be publishe
Automated image-based quality control of molecularly imprinted polymer films
We present results of applying a feature extraction process to images of coatings of
molecularly imprinted polymers (MIPs) coatings on glass substrates for defect detec-
tion. Geometric features such as MIP side lengths, aspect ratio, internal angles, edge
regularity, and edge strength are obtained by using Hough transforms, and Canny
edge detection. A Self Organizing Map (SOM) is used for classification of texture of
MIP surfaces. The SOM is trained on a data set comprised of images of manufactured
MIPs. The raw images are first processed using Hough transforms and Canny edge
detection to extract just the MIP-coated portion of the surface, allowing for surface
area estimation and reduction of training set size. The training data set is comprised
of 20-dimensional feature vectors, each of which is calculated from a single section of a
gray scale image of a MIP. Haralick textures are among the quantifiers used as feature
vector components. The training data is then processed using principal component
analysis to reduce the number of dimensions of the data set. After training, the SOM
is capable of classifying texture, including defects
Three Single Wheel Machines for Traction and Soil Compaction Research
Three single wheel machines for traction and soil compaction research have been developed in recent years at the USDA-ARS National Soil Dynamics Laboratory. The Traction Research Vehicle has been used extensively for soil bin traction and soil compaction experiments. The vehicle uses feedback computer control to control tire dynamic load, forward velocity, inflation pressure, and in a given run, either travel reduction or net traction. The all-terrain vehicle (ATV) tire single wheel machine has been used in determining traction and motion resistance characteristics of ATV tires in soil bins. The ATV tire machine uses the forward velocity feedback computer control of the Traction Research Vehicle and uses deadweight loading for dynamic load. Tire angular velocity is manually controlled by the operator using a joystick. A single wheel traction research machine designed for use in the field has been developed, but computer control has not been completed
Climate Modeling of a Potential ExoVenus
The planetary mass and radius sensitivity of exoplanet discovery capabilities
has reached into the terrestrial regime. The focus of such investigations is to
search within the Habitable Zone where a modern Earth-like atmosphere may be a
viable comparison. However, the detection bias of the transit and radial
velocity methods lies close to the host star where the received flux at the
planet may push the atmosphere into a runaway greenhouse state. One such
exoplanet discovery, Kepler-1649b, receives a similar flux from its star as
modern Venus does from the Sun, and so was categorized as a possible exoVenus.
Here we discuss the planetary parameters of Kepler-1649b with relation to Venus
to establish its potential as a Venus analog. We utilize the general
circulation model ROCKE-3D to simulate the evolution of the surface temperature
of Kepler-1649b under various assumptions, including relative atmospheric
abundances. We show that in all our simulations the atmospheric model rapidly
diverges from temperate surface conditions towards a runaway greenhouse with
rapidly escalating surface temperatures. We calculate transmission spectra for
the evolved atmosphere and discuss these spectra within the context of the
James Webb Space Telescope (JWST) Near-Infrared Spectrograph (NIRSpec)
capabilities. We thus demonstrate the detectability of the key atmospheric
signatures of possible runaway greenhouse transition states and outline the
future prospects of characterizing potential Venus analogs.Comment: 11 pages, 4 figures, 1 table, accepted for publication in the
Astrophysical Journal. The data from this paper are open source and are
available from the following data portals:
https://portal.nccs.nasa.gov/GISS_modelE/ROCKE-3D/Climate_Modeling_of_a_Potential_ExoVenus
https://archive.org/details/Climate_Modeling_of_a_Potential_ExoVenu
Heaven is a Place: The politics and poetics of LGBT location in a community dance film
The film, Heaven is a Place, received funding from The Culture Programme of the European Union, and The Humanities, Music and Performing Arts Research Centre (HuMPA) at University of Plymouth; with additional grant funding from The ICCI Support Fund, Innovation for the Creative and Cultural IndustriesThrough a discussion of a local, movement-based performance for and through digital video, this chapter draws upon a range of scholarly dis- ciplines (including performance studies, film studies, somatics, queer studies, urban studies and human geography) from the perspective of practitioner-researchers to re ect upon the implications and potentials of a community lmmaking practice that is simultaneously aesthetic, political, spatial and social. In particular, it considers how the process-driven triangulation of thinking bodies, sexual subjectivities and emplacement within such a practice might enable us to acknowledge, consolidate and reimagine a community that had been either erased or marginalised in dominant accounts of its city. Heaven Is a Place is a short dance film, made in 2014 by the authors of this chapter in collaboration with members of the lesbian, gay, bisexual and trans (LGBT) community in Plymouth in South West England. Filmed in some of Plymouth’s most visually spectacular, evocative and liminal waterside locations – its docksides, marinas, look-out points, cruising spots, clubs and bathing areas – it explores becoming, melan- choly and the erotics of place through the human geography of an ‘ocean city’. In addition to choreography arising from site-responsive physical vocabularies, the film features scenarios and movement scores that reflect personal memories and queer histories of the city, developed in the first instance through a series of movement workshops that were co-organised with the LGBT advocacy organisation, Pride in Plymouth
Gram-negative bacterial molecules associate with Alzheimer disease pathology.
ObjectiveWe determined whether Gram-negative bacterial molecules are associated with Alzheimer disease (AD) neuropathology given that previous studies demonstrate Gram-negative Escherichia coli bacteria can form extracellular amyloid and Gram-negative bacteria have been reported as the predominant bacteria found in normal human brains.MethodsBrain samples from gray and white matter were studied from patients with AD (n = 24) and age-matched controls (n = 18). Lipopolysaccharide (LPS) and E coli K99 pili protein were evaluated by Western blots and immunocytochemistry. Human brain samples were assessed for E coli DNA followed by DNA sequencing.ResultsLPS and E coli K99 were detected immunocytochemically in brain parenchyma and vessels in all AD and control brains. K99 levels measured using Western blots were greater in AD compared to control brains (p < 0.01) and K99 was localized to neuron-like cells in AD but not control brains. LPS levels were also greater in AD compared to control brain. LPS colocalized with Aβ1-40/42 in amyloid plaques and with Aβ1-40/42 around vessels in AD brains. DNA sequencing confirmed E coli DNA in human control and AD brains.ConclusionsE coli K99 and LPS levels were greater in AD compared to control brains. LPS colocalized with Aβ1-40/42 in amyloid plaques and around vessels in AD brain. The data show that Gram-negative bacterial molecules are associated with AD neuropathology. They are consistent with our LPS-ischemia-hypoxia rat model that produces myelin aggregates that colocalize with Aβ and resemble amyloid-like plaques
Climate Modeling of a Potential Exovenus
The planetary mass and radius sensitivity of exoplanet discovery capabilities has reached into the terrestrial regime. The focus of such investigations is to search within the Habitable Zone where a modern Earth-like atmosphere may be a viable comparison. However, the detection bias of the transit and radial velocity methods lies close to the host star where the received flux at the planet may push the atmosphere into a runaway greenhouse state. One such exoplanet discovery, Kepler-1649b, receives a similar flux from its star as modern Venus does from the Sun, and so was categorized as a possible exoVenus. Here we discuss the planetary parameters of Kepler-1649b in relation to Venus to establish its potential as a Venus analog. We utilize the general circulation model ROCKE-3D to simulate the evolution of the surface temperature of Kepler-1649b under various assumptions, including relative atmospheric abundances. We show that in all our simulations the atmospheric model rapidly diverges from temperate surface conditions toward a runaway greenhouse with rapidly escalating surface temperatures. We calculate transmission spectra for the evolved atmosphere and discuss these spectra within the context of the James Webb Space Telescope Near-Infrared Spectrograph capabilities. We thus demonstrate the detectability of the key atmospheric signatures of possible runaway greenhouse transition states and outline the future prospects of characterizing potential Venus analogs
A new high entropy alloy brazing filler metal design for joining skutterudite thermoelectrics to copper
A new High Entropy Alloy (HEA) in the ZnGaCu-(AuSn) system was designed to join skutterudite thermoelectrics (CoSb2.75Sn0.05Te0.20), with a diffusion barrier of Ni applied, to Cu. Such a joint could be part of a device for thermal energy recovery within automotive exhaust systems. A rapid large-scale screening calculation technique based on Python programming has been introduced to conduct the HEA selection process, resulting in a series of alloys, which have been experimentally verified. It is demonstrated that a particular ZnGaCu-(AuSn) HEA alloy can join Ni and Cu successfully; a good joint is formed, and the average electrical contact resistance of the interfaces after joining is promising at room temperature, which shows that it has the potential to improve on the existing fillers used in such applications. The alloy design methodology used here suggests a potential efficient route to design new filler metals for a wide array of applications in which existing filler metals are not suitable
X-ray Over-Luminous Elliptical Galaxies: A New Class of Mass Concentrations in the Universe?
We detect four isolated, X-ray over-luminous (Lx>2e43 [h/0.5]**-2 erg/s)
elliptical galaxies (OLEGs) in our 160 square degree ROSAT PSPC survey. The
extent of their X-ray emission, total X-ray luminosity, total mass, and mass of
the hot gas in these systems correspond to poor clusters, and the optical
luminosity of the central galaxies (M_R<-22.5 + 5 lg h) is comparable to that
of cluster cDs. However, there are no detectable fainter galaxy concentrations
around the central elliptical. The mass-to-light ratio within the radius of
detectable X-ray emission is in the range 250-450 Msun/Lsun, which is 2-3 times
higher than typically found in clusters or groups. These objects can be the
result of galaxy merging within a group. However, their high M/L values are
difficult to explain in this scenario. OLEGs must have been undisturbed for a
very long time, which makes them the ultimate examples of systmes in
hydrostatic equilibrium. The number density of OLEGs is n=2.4(+3.1-1.2}x10**-7
(h/0.5)**-3 Mpc**-3 at the 90% confidence. They comprise 20% of all clusters
and groups of comparable X-ray luminosity, and nearly all galaxies brighter
than M_R=-22.5. The estimated contirubution of OLEGs to the total mass density
in the Universe is close to that of T>7 keV clusters.Comment: 4 pages, 2 figures, uses emulateapj.sty, submitted to ApJ Letter
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