10,199 research outputs found
Black Holes and Vacuum Cleaners: Using Metaphor, Relevance, and Inquiry in Labels for Space Images
This study extended research on the development of explanatory labels for
astronomical images for the non-expert lay public. The research questions
addressed how labels with leading questions/metaphors and relevance to everyday
life affect comprehension of the intended message for deep space images, the
desire to learn more, and the aesthetic appreciation of images. Participants
were a convenience sample of 1,921 respondents solicited from a variety of
websites and through social media who completed an online survey that used four
high-resolution images as stimuli: Sagittarius A*, Solar Flare, Cassiopeia A,
and the Pinwheel Galaxy (M101). Participants were randomly assigned initially
to 1 of 3 label conditions: the standard label originally written for the
image, a label with a leading question containing a metaphor related to the
information for the image, or a label that contained a fact about the image
relevant to everyday life. Participants were randomly assigned to 1 image and
compared all labels for that image. Open-ended items at various points asked
participants to pose questions to a hypothetical astronomer. Main findings were
that the relevance condition was significantly more likely to increase wanting
to learn more; the original label was most likely to increase overall
appreciation; and, smart phone users were more likely to want to learn more and
report increased levels of appreciation. Results are discussed in terms of the
need to examine individual viewer characteristics and goals in creating
different labels for different audiences.Comment: 50 pages, 7 tables, 2 figures, accepted by the journal "Psychology of
Aesthetics, Creativity, and the Arts
A calculation of the elastic constants of yttrium and the rare-earth metals
A modified cellular method developed by Raimes was extended to scandium, yttrium, and the rare earth metals. The assumption that the valence electrons are free and share the same ground state wave functions at zero wave number, was capable of giving fairly good agreement between the calculated and experimental values of the atomic radii, compressibilities, and total energies of the trivalent rare-earth metals as well as for scandium and yttrium. In addition the calculated variation of atomic radius and compressibility of the hexagonal rare-earth metals with atomic number was in qualitative agreement with experiment. Calculations based on the assumption that europium and ytterbium are divalent in the solid state were capable of giving reasonable agreement with the observed atomic radii and compressibilities of these elements. Calculations for cerium did not give satisfactory agreement with the assumption of either a trivalent or quadrivalent atomic core. This failure probably results from the fact that the assumption of equivalent behavior of the valence electrons at zero wave number is quite poor for this element. The compressibilities of promethium and scandium were predicted.
A calculation of the elastic shear constants of hexagonal close-packed yttrium at 0°K was made based on the assumption of nearly-free electron behavior for the valence electrons. The method developed by Reitz and Smith for hexagonal close-packed metals was applied. In order to obtain reasonable agreement with the experimental values it was assumed that electron overlap had occurred across the {110,1} and {000, 2} faces of the Brillouin zone and that there are an appreciable nwnber of holes in the zone. The results are in agreement with the measured resistivity of single crystals of yttrium
Analysis of Toxic Amyloid Fibril Interactions at Natively Derived Membranes by Ellipsometry
There is an ongoing debate regarding the culprits of cytotoxicity associated with amyloid disorders. Although small pre-fibrillar amyloid oligomers have been implicated as the primary toxic species, the fibrillar amyloid material itself can also induce cytotoxicity. To investigate membrane disruption and cytotoxic effects associated with intact and fragmented fibrils, the novel in situ spectroscopic technique of Total Internal Reflection Ellipsometry (TIRE) was used. Fibril lipid interactions were monitored using natively derived whole cell membranes as a model of the in vivo environment. We show that fragmented fibrils have an increased ability to disrupt these natively derived membranes by causing a loss of material from the deposited surface when compared with unfragmented fibrils. This effect was corroborated by observations of membrane disruption in live cells, and by dye release assay using synthetic liposomes. Through these studies we demonstrate the use of TIRE for the analysis of protein-lipid interactions on natively derived lipid surfaces, and provide an explanation on how amyloid fibrils can cause a toxic gain of function, while entangled amyloid plaques exert minimal biological activity
Cessation of X-ray Pulsation of GX 1+4
We report results from our weekly monitoring campaign on the X-ray pulsar GX
1+4 with the {\em Rossi X-ray Timing Explorer} satellite. The spin-down trend
of GX 1+4 was continuing, with the pulsar being at its longest period ever
measured (about 138.7 s). At the late stage of the campaign, the source entered
an extended faint state, when its X-ray (2-60 keV) flux decreased significantly
to an average level of . It was
highly variable in the faint state; the flux dropped to as low as . In several observations during this
period, the X-ray pulsation became undetectable. We can, therefore, conclude
conservatively that the pulsed fraction, which is normally 70%
(peak-to-peak), must have decreased drastically in those cases. This is very
similar to what was observed of GX 1+4 in 1996 when it became similarly faint
in X-ray. In fact, the flux at which the cessation of X-ray pulsation first
occurred is nearly the same as it was in 1996. We suggest that we have, once
again, observed the propeller effect in GX 1+4, a phenomenon that is predicted
by theoretical models of accreting X-ray pulsars.Comment: 13 pages, 9 figures (available at
http://www.physics.purdue.edu/~cui/ftp/cuifigs.tar.gz). To appear in Ap
Diverse Stellar Haloes in Nearby Milky Way-Mass Disc Galaxies
We have examined the resolved stellar populations at large galactocentric
distances along the minor axis (from 10 kpc up to between 40 and 75 kpc), with
limited major axis coverage, of six nearby highly-inclined Milky Way-mass disc
galaxies using HST data from the GHOSTS survey. We select red giant branch
stars to derive stellar halo density profiles. The projected minor axis density
profiles can be approximated by power laws with projected slopes of between
and and a diversity of stellar halo masses of , or of the total galaxy stellar masses. The typical
intrinsic scatter around a smooth power law fit is dex owing to
substructure. By comparing the minor and major axis profiles, we infer
projected axis ratios at kpc between . The GHOSTS
stellar haloes are diverse, lying between the extremes charted out by the
(rather atypical) haloes of the Milky Way and M31. We find a strong correlation
between the stellar halo metallicities and the stellar halo masses. We compare
our results with cosmological models, finding good agreement between our
observations and accretion-only models where the stellar haloes are formed by
the disruption of dwarf satellites. In particular, the strong observed
correlation between stellar halo metallicity and mass is naturally reproduced.
Low-resolution hydrodynamical models have unrealistically high stellar halo
masses. Current high-resolution hydrodynamical models appear to predict stellar
halo masses somewhat higher than observed but with reasonable metallicities,
metallicity gradients and density profiles.Comment: 26 pages, 17 figures. Accepted for publication in MNRA
Public Health Outcomes as a Measure of Efficacy of Syringe Exchange Programs
Introduction. A syringe exchange is a public health intervention that offers nonjudgmental services to intravenous drug users (IVDU), providing clean syringes in exchange for used syringes. While prior studies demonstrated that syringe exchanges can reduce transmission of HIV, hepatitis C, and other blood-borne pathogens, other measures of health improvements have been less studied.
Methods. 91 members of Vermont CARES syringe exchange program were surveyed on their healthcare practices. New members were defined asprogram.
Results. Long-term members tended to have a primary care provider (PCP). Lack of insurance and fear of judgment were commonly cited reasons for not having a PCP. Long-term members were significantly less likely (p=0.04) to use costly emergency department (ED) services and less likely to reuse their own or another person\u27s needles. Long-term members were more likely to be in addiction treatment and reported a greater desire to abstain from drug use. New members were more likely to obtain hepatitis C and HIV testing in the past year.
Discussion. Subjects responded positively to the possibility of accessing PCP services through VT CARES, offering a continuation of the nonjudgmental healthcare environment. Decreased ED visits significantly correlated with longer membership, reflecting the positive impact of the syringe exchange education services on reducing healthcare costs. Decreased testing among long-term members may reflect prior knowledge of their status. Long-term members were less likely to reuse their own needles or ones used by another person, suggesting the distribution of clean syringes encourages safer injection practices.https://scholarworks.uvm.edu/comphp_gallery/1247/thumbnail.jp
The Ursinus Weekly, December 18, 1916
Schaff anniversary observed on Friday • Memorial service for late Mr. Dimon • Ursinus quintet loses to Temple • Christmas in Hawaii • College directory • A Christmas hymn: the Christ child • Resolutions • On the campushttps://digitalcommons.ursinus.edu/weekly/2575/thumbnail.jp
Dynamic Neutron Scattering from Conformational Dynamics II: Application using Molecular Dynamics Simulation and Markov modeling
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