5,492 research outputs found
Do actions occur inside the body?
The paper offers a critical examination of Jennifer Hornsby's view that actions are internal to the body. It focuses on three of Hornsby's central claims: (P) many actions are bodily movements (in a special sense of the word âmovementâ) (Q) all actions are tryings; and (R) all actions occur inside the body. It is argued, contra Hornsby, that we may accept (P) and (Q) without accepting also the implausible (R). Two arguments are first offered in favour of the thesis (Contrary-R): that no actions occur inside the body. Three of Hornsby's arguments in favour of R are then examined. It is argued that we need to make a distinction between the causes and the causings of bodily movements (in the ordinary sense of the word âmovementâ) and that actions ought to be identified with the latter rather than the former. This distinction is then used to show how Hornsby's arguments for (R) may be resisted
The critical current of YBa2Cu3O7-d Low Angle Grain Boundaries
Transport critical current measurements have been performed on 5 degree
[001]-tilt thin film YBa2Cu3O7-delta single grain boundaries with magnetic
field rotated in the plane of the film, phi. The variation of the critical
current has been determined as a function of the angle between the magnetic
field and the grain boundary plane. In applied fields above 1 T the critical
current, j_c, is found to be strongly suppressed only when the magnetic field
is within an angle phi_k of the grain boundary. Outside this angular range the
behavior of the artificial grain boundary is dominated by the critical current
of the grains. We show that the phi dependence of j_c in the suppressed region
is well described by a flux cutting model.Comment: To be published in PRL, new version with minor changes following
referees report
Suppressed dependence of polarization on epitaxial strain in highly polar ferroelectrics
A combined experimental and computational investigation of coupling between
polarization and epitaxial strain in highly polar ferroelectric
PbZr_0.2Ti_0.8O_3 (PZT) thin films is reported. A comparison of the properties
of relaxed (tetragonality c/a = 1.05) and highly-strained (c/a = 1.09)
epitaxial films shows that polarization, while being amongst the highest
reported for PZT or PbTiO_3 in either film or bulk forms (P_r = 82
microC/cm^2), is almost independent of the epitaxial strain. We attribute this
behavior to a suppressed sensitivity of the A-site cations to epitaxial strain
in these Pb-based perovskites, where the ferroelectric displacements are
already large, contrary to the case of less polar perovskites, such as BaTiO_3.
In the latter case, the A-site cation (Ba) and equatorial oxygen displacements
can lead to substantial polarization increases.Comment: 4 pages, 3 figure
The Epistemology of Intentionality: Notional Constituents vs. Direct Grasp
Franz Brentano is well known for highlighting the importance of intentionality, but he said curiously little about the nature of intentionality. According to Mark Textor, there is a deep reason for this: Brentano took intentionality to be a conceptual primitive the nature of which is revealed only in direct grasp. Although there is certainly textual support for this interpretation, it appears in tension with Brentanoâs repeated attempts to analyze intentionality in terms of ânotional constituentsâ â aspects of intentionality which cannot come apart in reality but which can be conceptually distinguished. After bringing out this tension, I explore some options for resolving it, ultimately offering my own favored interpretation
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Assessment of novel binocular colour, motion and contrast tests in glaucoma
The effects of glaucoma on binocular visual sensitivity for the detection of various stimulus attributes are investigated at the fovea and in four paracentral retinal regions. The study employed a number of visual stimuli designed to isolate the processing of various stimulus attributes. We measured absolute contrast detection thresholds and functional contrast sensitivity by using Landolt ring stimuli. This psychophysical Landolt C-based contrast test of detection and gap discrimination allowed us to test parafoveally at 6 ° from fixation and foveally by employing interleaved testing locations. First-order motion perception was examined by using moving stimuli embedded in static luminance contrast noise. Red/green (RG) and yellow/blue (YB) colour thresholds were measured with the Colour Assessment and Diagnosis (CAD) test, which utilises random dynamic luminance contrast noise (± 45 %) to ensure that only colour and not luminance signals are available for target detection. Subjects were normal controls (nâ=â65) and glaucoma patients with binocular visual field defects (nâ=â15) classified based on their Humphrey Field Analyzer mean deviation (MD) scores. The impairment of visual function varied depending on the stimulus attribute and location tested. Progression of loss was noted for all tests as the degree of glaucoma increased. For subjects with mild glaucoma (MD â0.01 dB to â6.00 dB) significantly more data points fell outside the normal age-representative range for RG colour thresholds than for any other visual test, followed by motion thresholds. This was particularly the case for the parafoveal data compared with the foveal data. Thus, a multifaceted measure of binocular visual performance, incorporating RG colour and motion test at multiple locations, might provide a better index for comparison with quality of life measures in glaucoma
Fracture of complex metallic alloys: An atomistic study of model systems
Molecular dynamics simulations of crack propagation are performed for two
extreme cases of complex metallic alloys (CMAs): In a model quasicrystal the
structure is determined by clusters of atoms, whereas the model C15 Laves phase
is a simple periodic stacking of a unit cell. The simulations reveal that the
basic building units of the structures also govern their fracture behaviour.
Atoms in the Laves phase play a comparable role to the clusters in the
quasicrystal. Although the latter are not rigid units, they have to be regarded
as significant physical entities.Comment: 6 pages, 4 figures, for associated avi file, see
http://www.itap.physik.uni-stuttgart.de/~frohmut/MOVIES/C15.LJ.011.100.av
Anthropogenic lead isotopes in Antarctica
We report the first measurements of Pb isotopes in Antarctic snow, which show that even recent snow containing 2.3 pg/g is highly polluted with anthropogenic Pb. This follows from a comparison of isotope abundances of Pb in surface snow and terrestrial dust extracted from ancient Antarctic ice (Dome C, depth 308 m, approximate age 7,500 a BP), the latter being distinctly more radiogenic. This result is independent of geochemical arguments based on measurements of Al, Na and SO_4. South America is suggested as a likely source of this anthropogenic Pb. The presence of significantly less radiogenic Pb in the snow adjacent to two Antarctic base stations indicates that there is contamination from station emissions, although emission from Australia is an alternative explanation for a site 33 km from Dumont d'Urville
Sub-Angstrom Microscopy Through Incoherent Imaging and Image Reconstruction
Z-contrast scanning transmission electron microscopy (STEM) with a high-angle annular detector breaks the coherence of the imaging process, and provides an incoherent image of a crystal projection. Even in the presence of strong dynamical diffraction, the image can be accurately described as a convolution between an object function, sharply peaked at the projected atomic sites, and the probe intensity profile. Such an image can be inverted intuitively without the need for model structures, and therefore provides the important capability to reveal unanticipated interfacial arrangements. It represents a direct image of the crystal projection, revealing the location of the atomic columns and their relative high-angle scattering power. Since no phase is associated with a peak in the object function or the contrast transfer function, extension to higher resolution is also straightforward. Image restoration techniques such as maximum entropy, in conjunction with the 1.3 A probe anticipated for a 300 kV STEM, appear to provide a simple and robust route to the achievement of sub-Angstrom resolution electron microscopy
Towards sub-kpc scale kinematics of molecular and ionized gas of star-forming galaxies at z similar to 1
We compare the molecular and ionized gas kinematics of two strongly lensed
galaxies at based on observations from ALMA and MUSE. We derive the CO
and [OII] rotation curves and dispersion profiles of these two galaxies. We
find a difference between the observed molecular and ionized gas rotation
curves for one of the galaxies, the Cosmic Snake, for which we obtain a spatial
resolution of few hundred parsecs along the major axis. The rotation curve of
the molecular gas is steeper than the rotation curve of the ionized gas. In the
second galaxy, A521, the molecular and ionized gas rotation curves are
consistent, but the spatial resolution is only of few kpc on the major axis.
Using simulations, we investigate the effect of the thickness of the gas disk
and effective radius on the observed rotation curves and find that a more
extended and thicker disk smooths the curve. We also find that the presence of
a strongly inclined thick disk (>1 kpc) can smooth the rotation curve because
it degrades the spatial resolution along the line of sight. By building a model
using a stellar disk and two gas disks, we reproduce the rotation curves of the
Cosmic Snake with a molecular gas disk that is more massive and more radially
and vertically concentrated than the ionized gas disk. Finally, we also obtain
an intrinsic velocity dispersion in the Cosmic Snake of 18.5+-7 km/s and
19.5+-6 km/s for the molecular and ionized gas, respectively, which is
consistent with a molecular disk with a smaller and thinner disk. For A521, the
intrinsic velocity dispersion values are 11+-8 km/s and 54+-11 km/s, with a
higher value for the ionized gas. This could indicate that the ionized gas disk
is thicker and more turbulent in this galaxy. These results highlight the
different spatial distribution of the molecular and ionized gas disks at
and suggest the presence of thick ionized gas disks at this epoch.Comment: 11 pages, 8 figures, accepted for publication in A&
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