2,878 research outputs found
Is economic planning hypercomputational? The argument from Cantor diagonalisation
Murphy [26] argues that the diagonal argument of the number theorist Cantor can be used to elucidate issues that arose in the socialist calculation debate of the 1930s. In particular he contends that the diagonal argument buttresses the claims of the Austrian economists regarding the impossibility of rational planning.We challenge Murphy’s argument, both at the number theoretic level and from the standpoint of economic realism
PTRE-seq reveals mechanism and interactions of RNA binding proteins and miRNAs
A large number of RNA binding proteins (RBPs) and miRNAs bind to the 3′ untranslated regions of mRNA, but methods to dissect their function and interactions are lacking. Here the authors introduce post-transcriptional regulatory element sequencing (PTRE-seq) to dissect sequence preferences, interactions and consequences of RBP and miRNA binding
Critical Dynamics of Burst Instabilities in the Portevin-Le Chatelier Effect
We investigate the Portevin-Le Chatelier effect (PLC), by compressing Al-Mg
alloys in a very large deformation range, and interpret the results from the
viewpoint of phase transitions and critical phenomena. The system undergoes two
dynamical phase transitions between intermittent (or "jerky") and "laminar"
plastic dynamic phases. Near these two dynamic critical points, the order
parameter 1/\tau of the PLC effect exhibits large fluctuations, and "critical
slowing down" (i.e., the number of bursts, or plastic instabilities, per
unit time slows down considerably).Comment: the published 4-page version is in the PRL web sit
Multifractal burst in the spatio-temporal dynamics of jerky flow
The collective behavior of dislocations in jerky flow is studied in Al-Mg
polycrystalline samples subjected to constant strain rate tests. Complementary
dynamical, statistical and multifractal analyses are carried out on the
stress-time series recorded during jerky flow to characterize the distinct
spatio-temporal dynamical regimes. It is shown that the hopping type B and the
propagating type A bands correspond to chaotic and self-organized critical
states respectively. The crossover between these types of bands is identified
by a large spread in the multifractal spectrum. These results are interpreted
on the basis of competing scales and mechanisms.Comment: 4 pages, 6 figures To be published in Phys. Rev. Lett. (2001
Piezomagnetism and Stress Induced Paramagnetic Meissner Effect in Mechanically Loaded High-T_c Granular Superconductors
Two novel phenomena in a weakly coupled granular superconductor under an
applied stress are predicted which are based on recently suggested piezophase
effect (a macroscopic quantum analog of the piezoelectric effect) in
mechanically loaded grain boundary Josephson junctions. Namely, we consider the
existence of stress induced paramagnetic moment in zero applied magnetic field
(piezomagnetism) and its influence on a low-field magnetization (leading to a
mechanically induced paramagnetic Meissner effect). The conditions under which
these two effects can be experimentally measured in high-T_$ granular
superconductors are discussed.Comment: 4 pages (REVTEX, epsf.sty), 2 PS figure
Clinicians' Perspectives of a Novel Home-based Multidisciplinary Telehealth Service for Patients with Chronic Spinal Pain
Chronic spinal pain conditions can often be successfully managed by a non-surgical, multidisciplinary approach, however many individuals are unable to access such specialised services within their local community. A possible solution may be the delivery of care via telerehabilitation. This study aimed to evaluate clinicians’ perspectives on providing clinical care via telerehabilitation during the early implementation of a novel spinal telerehabilitation service. Eight clinicians’ were recruited, completing surveys at four separate time points. Confidence in providing treatment via telerehabilitation significantly improved with time (?2(3)=16.22, p=0.001). Clinicians became significantly more accepting of telerehabilitation being a time- (?2(3)=11.237, p=0.011), and cost-effective (?2(3)=9.466, p=0.024) platform in which they could deliver care. Overall satisfaction was high, with technology becoming easier to use (p=0.026) and ability to establish rapport significantly improved with experience (p=0.043). Understanding clinicians’ perspectives throughout the early implementation phase of a new telerehabilitation service is a critical component in determining long-term sustainability.
Observation of the Halo of NGC 3077 Near the "Garland" Region Using the Hubble Space Telescope
We report the detection of upper main sequence stars and red giant branch
stars in the halo of an amorphous galaxy, NGC3077. The observations were made
using Wide Field Planetary Camera~2 on board the Hubble Space Telescope. The
red giant branch luminosity function in I-band shows a sudden discontinuity at
I = 24.0 +- 0.1 mag. Identifying this with the tip of the red giant branch
(TRGB), and adopting the calibration provided by Lee, Freedman, & Madore (1993)
and the foreground extinction of A_B = 0.21 mag, we obtain a distance modulus
of (m-M)_0 = 27.93 +- 0.14(random) +- 0.16(sys). This value agrees well with
the distance estimates of four other galaxies in the M81 Group. In addition to
the RGB stars, we observe a concentration of upper main sequence stars in the
halo of NGC3077, which coincides partially with a feature known as the
``Garland''. Using Padua isochrones, these stars are estimated to be <150 Myrs
old. Assuming that the nearest encounter between NGC3077 and M81 occurred 280
Myrs ago as predicted by the numerical simulations (Yun 1997), the observed
upper main sequence stars are likely the results of the star formation
triggered by the M81-NGC3077 tidal interaction.Comment: 15 pages, 8 figures. Accepted for publication in Astrophysical
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