3,950 research outputs found
Variations in in vivo phosphorylation at the proline-rich domain of the microtubule-associated protein 2 (MAP2) during rat brain development
Astroclimate at San Pedro M\'artir I: 2004-2008 Seeing Statistics from the TMT Site Testing Data
We present comprehensive seeing statistics for the San Pedro M\'artir site
derived from the Thirty Meter Telescope site selection data. The observations
were obtained between 2004 and 2008 with a Differential Image Motion Monitor
(DIMM) and a Multi Aperture Scintillation Sensor (MASS) combined instrument
(MASS--DIMM). The parameters that are statistically analised here are: whole
atmosphere seeing -measured by the DIMM-; free atmosphere seeing --measured by
the MASS--; and ground-layer seeing (GL) --difference between the total and
free-atmosphere seeing--. We made a careful data coverage study along with
statistical distributions of simultaneous MASS--DIMM seeing measurements, in
order to investigate the nightly, monthly, seasonal, annual and global
behaviour, as well as possible hourly seeing trends. Although this campaign
covers five years, the sampling is uneven, being 2006 and 2007 the best sampled
years in terms of seasonal coverage. The overall results yield a median seeing
of 0.78 (DIMM), 0.37 (MASS) and 0.59 arcsec (GL). The strongest contribution to
the whole atmosphere seeing comes, therefore, from a strong ground layer. We
find that the best season is summer, while the worst one is winter, in
accordance with previous studies. It is worth noting that the best yearly
results are correlated with the best sampled years. The hourly analysis shows
that there is no statistically significant tendency of seeing degradation
towards dawn. The seeing values are slightly larger than those reported before.
This may be caused by climate changes.Comment: Accepted for publication (2012 June 14) in MNRAS, 15 pages, 16
Figures, 8 Table
Dark Matter Subhalos in the Ursa Minor Dwarf Galaxy
Through numerical simulations, we study the dissolution timescale of the Ursa
Minor cold stellar clump, due to the combination of phase-mixing and
gravitational encounters with compact dark substructures in the halo of Ursa
Minor. We compare two scenarios; one where the dark halo is made up by a smooth
mass distribution of light particles and one where the halo contains 10% of its
mass in the form of substructures (subhalos). In a smooth halo, the stellar
clump survives for a Hubble time provided that the dark matter halo has a big
core. In contrast, when the point-mass dark substructures are added, the clump
survives barely for \sim 1.5 Gyr. These results suggest a strong test to the
\Lambda-cold dark matter scenario at dwarf galaxy scale.Comment: accepted for publication in Ap
Angle-resolved photoemission study and first principles calculation of the electronic structure of GaTe
The electronic band structure of GaTe has been calculated by numerical atomic
orbitals density-functional theory, in the local density approximation. In
addition, the valence-band dispersion along various directions of the GaTe
Brillouin zone has been determined experimentally by angle-resolved
photoelectron spectroscopy. Along these directions, the calculated valence-band
structure is in good concordance with the valence-band dispersion obtained by
these measurements. It has been established that GaTe is a direct-gap
semiconductor with the band gap located at the Z point, that is, at Brillouin
zone border in the direction perpendicular to the layers. The valence-band
maximum shows a marked \textit{p}-like behavior, with a pronounced anion
contribution. The conduction band minimum arises from states with a comparable
\textit{s}- \textit{p}-cation and \textit{p}-anion orbital contribution.
Spin-orbit interaction appears to specially alter dispersion and binding energy
of states of the topmost valence bands lying at . By spin-orbit, it is
favored hybridization of the topmost \textit{p}-valence band with deeper
and flatter \textit{p}-\textit{p} bands and the valence-band minimum at
is raised towards the Fermi level since it appears to be determined by
the shifted up \textit{p}-\textit{p} bands.Comment: 7 text pages, 6 eps figures, submitted to PR
Plasma Rich in Growth Factors Membrane as Coadjuvant Treatment in the Surgery of Ocular Surface Disorders
To evaluate the safety and efficacy of the surgical use of plasma rich in growth factors fibrin membrane (mPRGF) in different ocular surface pathologies.Fifteen patients with different corneal and conjunctival diseases were included in the study. Patients were grouped according to the use of mPRGF as graft (corneal and/or conjunctival) or dressing; they were also grouped according to the surgical subgroup of intervention (persistent corneal ulcer [PCU], keratoplasty, superficial keratectomy, corneal perforation, and pterygium). Best corrected visual acuity, intraocular pressure (IOP), inflammation control time (ICT), mPRGF AT (PRGF membrane absorption time), and the healing time of the epithelial defect (HTED) were evaluated throughout the clinical follow-up time. Safety assessment was also performed reporting all adverse events.mPRGF showed a total closure of the defect in 13 of 15 patients (86.7%) and a partial closure in 2 patients (13.3%). The mean follow-up time was 11.14.2 (4.8-22.8) months, the mean ICT was 2.5 +/- 1.1 (1.0-4.0) months, the mean mPRGF AT was 12.4 +/- 2.0 (10.0-16.0) days, and for the global HTED the mean was 2.9 +/- 1.2 (1-4.8) months. Results showed an improvement in BCVA in all patients, with an overall improvement of 2.9 in Vision Lines. The BCVA significantly improved (P.05) throughout the clinical follow-up time. No adverse events were reported after mPRGF use.The mPRGF is effective and safe as coadjuvant treatment in surgeries related with ocular surface disorders, being an alternative to the use of amniotic membrane. The mPRGF accelerates tissue regeneration after ocular surface surgery thus minimizing inflammation and fibrosis.This study received funding from the Ministry of Economy and Competitiveness of the Spanish Government, within the project denominated SURFEYE (reference RTC-2014-2375-1)
Neuropsychological Test Barcelona-2: Theoretical and Practical Aspects
The Barcelona test (TB) is an instrument of neuropsychological assessment, developed under the influence of Luria’s ideas, and published in 1990 [1]. It explores the main cognitive functions and allows the design of graphic profiles similar to those of the Boston Test for the diagnosis of aphasia. Objective: To present the theoretical and practical characteristics of a new version of the test, the Test Barcelona-2. The new and computerized versions of test structure is described here with six modules established: (1) Language-attention-orientation; (2) Reading and writing; (3) Motorpraxis; (4) Perception-gnosis; (5) Memory; (6) Abstraction-execution. As a novelty, test allows the selection for specific profiles: alpha, beta, abbreviated, aphasia, andecological-forensic approach. The types of variables condition a different statistical approach and a differentiated form of graphic expression. The new test presents a modular structure, which allows determining intra- and inter-module dissociations. Computerization greatly facilitates the work of the clinician. In the case of aphasia the test allows to differentiate easily all its clinical forms.
Keywords: Test Barceona-2, neuropsychological test; computerized workstation, modular structur
Quantum-well states in ultrathin Ag(111) films deposited onto H-passivated Si(111)-(1x1) surfaces
Ag(111) films were deposited at room temperature onto H-passivated
Si(111)-(1x1) substrates, and subsequently annealed at 300 C. An abrupt
non-reactive Ag/Si interface is formed, and very uniform non-strained Ag(111)
films of 6-12 monolayers have been grown. Angle resolved photoemission
spectroscopy has been used to study the valence band electronic properties of
these films. Well-defined Ag sp quantum-well states (QWS) have been observed at
discrete energies between 0.5-2eV below the Fermi level, and their dispersions
have been measured along the GammaK, GammaMM'and GammaL symmetry directions.
QWS show a parabolic bidimensional dispersion, with in-plane effective mass of
0.38-0.50mo, along the GammaK and GammaMM' directions, whereas no dispersion
has been found along the GammaL direction, indicating the low-dimensional
electronic character of these states. The binding energy dependence of the QWS
as a function of Ag film thickness has been analyzed in the framework of the
phase accumulation model. According to this model, a reflectivity of 70% has
been estimated for the Ag-sp states at the Ag/H/Si(111)-(1x1) interface.Comment: 6 pages, 6 figures, submitted to Phys. Rev.
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