10,240 research outputs found
Cyclophilin-A is bound to through its peptidylprolyl isomerase domain to the cytoplasmic dynein motor protein complex
Although cyclophilin A (CyP-A) is a relatively abundant small immunophilin present in the cytoplasm of all mammalian cells, its general function(s) in the absence of the immunosuppressant drug cyclosporin A is not known. In contrast, the high molecular weight hsp90-binding immunophilins appear to play a role in protein trafficking in that they have been shown to link glucocorticoid receptor-hsp90 and p53.hsp90 complexes to the dynein motor protein for retrograde movement along microtubules. These immunophilins link to cytoplasmic dynein indirectly through the association of the immunophilin peptidylprolyl isomerase (PPIase) domain with dynamitin, a component of the dynein-associated dynactin complex (Galigniana, M. D., Harrell, J. M., O'Hagen, H. M., Ljungman, M., and Pratt, W. B. (2004) J. Biol. Chem. 279, 22483-22489). Here, we show that CyP-A exists in native heterocomplexes containing cytoplasmic dynein that can be formed in cell-free systems. Prolyl isomerase activity is not required for forming the dynein complex, but the PPIase domain fragment of FKBP52 blocks complex formation and CyP-A binds to dynamitin in a PPIase domain-dependent manner. CyP-A heterocomplexes containing tubulin and dynein can be formed in cytosol prepared under microtubule-stabilizing conditions, and CyP-A colocalizes in mouse fibroblasts with microtubules. Colocalization with microtubules is disrupted by overexpression of the PPIase domain fragment. Thus, we conclude that CyP-A associates in vitro and in vivo with the dynein/dynactin motor protein complex and we suggest that CyP-A may perform a general function related to the binding of cargo for retrograde movement along microtubules.Fil: Galigniana, Mario Daniel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de QuĂmica BiolĂłgica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. University of Michigan; Estados UnidosFil: Morishima, Yoshihiro. University of Michigan; Estados UnidosFil: Gallay, Philippe A.. The Scripps Research Institute; Estados UnidosFil: Pratt, William B.. University of Michigan; Estados Unido
Equational reasoning with context-free families of string diagrams
String diagrams provide an intuitive language for expressing networks of
interacting processes graphically. A discrete representation of string
diagrams, called string graphs, allows for mechanised equational reasoning by
double-pushout rewriting. However, one often wishes to express not just single
equations, but entire families of equations between diagrams of arbitrary size.
To do this we define a class of context-free grammars, called B-ESG grammars,
that are suitable for defining entire families of string graphs, and crucially,
of string graph rewrite rules. We show that the language-membership and
match-enumeration problems are decidable for these grammars, and hence that
there is an algorithm for rewriting string graphs according to B-ESG rewrite
patterns. We also show that it is possible to reason at the level of grammars
by providing a simple method for transforming a grammar by string graph
rewriting, and showing admissibility of the induced B-ESG rewrite pattern.Comment: International Conference on Graph Transformation, ICGT 2015. The
final publication is available at Springer via
http://dx.doi.org/10.1007/978-3-319-21145-9_
Constraining the initial temperature and shear viscosity in a hybrid hydrodynamic model of =200 GeV Au+Au collisions using pion spectra, elliptic flow, and femtoscopic radii
A new framework for evaluating hydrodynamic models of relativistic heavy ion
collisions has been developed. This framework, a Comprehesive Heavy Ion Model
Evaluation and Reporting Algorithm (CHIMERA) has been implemented by augmenting
UVH 2+1D viscous hydrodynamic model with eccentricity fluctuations,
pre-equilibrium flow, and the Ultra-relativistic Quantum Molecular Dynamic
(UrQMD) hadronic cascade. A range of initial temperatures and shear viscosity
to entropy ratios were evaluated for four initial profiles, and
scaling with and without pre-equilibrium flow. The model results
were compared to pion spectra, elliptic flow, and femtoscopic radii from 200
GeV Au+Au collisions for the 0--20% centrality range.Two sets of initial
density profiles, scaling with pre-equilibrium flow and
scaling without were shown to provide a consistent description of all three
measurements.Comment: 21 pages, 32 figures, version 3 includes additional text for
clarification, division of figures into more manageable units, and placement
of chi-squared values in tables for ease of viewin
XMM-Newton detection of two clusters of galaxies with strong SPT Sunyaev-Zel'dovich effect signatures
We report on the discovery of two galaxy clusters, SPT-CL J2332-5358 and
SPT-CL J2342-5411, in X-rays. These clusters were also independently detected
through their Sunyaev-Zel'dovich effect by the South Pole Telescope, and
confirmed in the optical band by the Blanco Cosmology Survey. They are thus the
first clusters detected under survey conditions by all major cluster search
approaches. The X-ray detection is made within the frame of the XMM-BCS cluster
survey utilizing a novel XMM-Newton mosaic mode of observations. The present
study makes the first scientific use of this operation mode. We estimate the
X-ray spectroscopic temperature of SPT-CL J2332-5358 (at redshift z=0.32) to T
= 9.3 (+3.3/-1.9) keV, implying a high mass, M_{500} = 8.8 +/- 3.8 \times
10^{14} M_{sun}. For SPT-CL J2342-5411, at z=1.08, the available X-ray data
doesn't allow us to directly estimate the temperature with good confidence.
However, using our measured luminosity and scaling relations we estimate that T
= 4.5 +/- 1.3 keV and M_{500} = 1.9 +/- 0.8 \times 10^{14} M_{sun}. We find a
good agreement between the X-ray masses and those estimated from the
Sunyaev-Zel'dovich effect.Comment: Submitted to A&A, 8 pages, 5 figures, 1 tabl
Canonical and Microcanonical Distributions for Fermi Systems
Recursion relations are presented that allow exact calculation of canonical
and microcanonical partition functions of degenerate Fermi systems, assuming no
explicit two-body interactions. Calculations of the level density, sorted by
angular momentum, are presented for Ni-56 are presented. The issue of treating
unbound states is also addressed.Comment: 5 pages, 5 figure
Isospin Fluctuations from a Thermally Equilibrated Hadron Gas
Partition functions, multiplicity distributions, and isospin fluctuations are
calculated for canonical ensembles in which additive quantum numbers as well as
total isospin are strictly conserved. When properly accounting for
Bose-Einstein symmetrization, the multiplicity distributions of neutral pions
in a pion gas are significantly broader as compared to the non-degenerate case.
Inclusion of resonances compensates for this broadening effect. Recursion
relations are derived which allow calculation of exact results with modest
computer time.Comment: 10 pages, 5 figure
Relation between concurrence and Berry phase of an entangled state of two spin 1/2 particles
We have studied here the influence of the Berry phase generated due to a
cyclic evolution of an entangled state of two spin 1/2 particles. It is shown
that the measure of formation of entanglement is related to the cyclic
geometric phase of the individual spins. \\Comment: 6 pages. Accepted in Europhys. Letters (likely to be published in vol
73, pp1-6 (2006)
Is the attentional SNARC effect truly attentional? : Using temporal order judgements to differentiate attention from response
Funding: The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: Financial support for this study was provided in part by a Natural Science and Engineering Research Council of Canada Discovery Grant (2016-06359) awarded to Jay Pratt. The funding agreement ensured the authorsâ independence in designing the study, interpreting the data, writing, and publishing the report.Peer reviewe
First measurements of the flux integral with the NIST-4 watt balance
In early 2014, construction of a new watt balance, named NIST-4, has started
at the National Institute of Standards and Technology (NIST). In a watt
balance, the gravitational force of an unknown mass is compensated by an
electromagnetic force produced by a coil in a magnet system. The
electromagnetic force depends on the current in the coil and the magnetic flux
integral. Most watt balances feature an additional calibration mode, referred
to as velocity mode, which allows one to measure the magnetic flux integral to
high precision. In this article we describe first measurements of the flux
integral in the new watt balance. We introduce measurement and data analysis
techniques to assess the quality of the measurements and the adverse effects of
vibrations on the instrument.Comment: 7 pages, 8 figures, accepted for publication in IEEE Trans. Instrum.
Meas. This Journal can be found online at
http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=1
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