2,184 research outputs found
055 HYPOXIA CONDITIONS DIFFERENTIALLY MODULATE NORMAL AND OSTEOARTHRITIC HUMAN ARTICULAR CHONDROCYTE PROTEOMES
Multitasking Compensatory Saccadic Training Program for Hemianopia Patients: A New Approach With 3-Dimensional Real-World Objects
Producción CientíficaPurpose: To examinewhether a noncomputerized multitasking compensatory saccadic
training program (MCSTP) for patients with hemianopia, based on a reading
regimen and eight exercises that recreate everyday visuomotor activities using threedimensional
(3D) real-world objects, improves the visual ability/function, quality of life
(QL), and functional independence (FI).
Methods: The 3D-MCSTP included four in-office visits and two customized homebased
daily training sessions over 12weeks. A quasiexperimental, pretest/posttest study
designwas carried out with an intervention group (IG) (n = 20) and a no-training group
(NTG) (n = 20) matched for age, hemianopia type, and brain injury duration.
Results: The groups were comparable for the main baseline variables and all participants
(n = 40) completed the study. The IGmainly showed significant improvements in
visual-processing speed (57.34% ± 19.28%; P < 0.0001) and visual attention/retention
ability (26.67% ± 19.21%; P < 0.0001), which also were significantly greater (P < 0.05)
than in the NTG. Moreover, the IG showed large effect sizes (Cohen’s d) in 75% of the
totalQL and FI dimensions analyzed; in contrast to the NTGthat showed negligiblemean
effect sizes in 96% of these dimensions.
Conclusions: The customized 3D-MCSTP was associated with a satisfactory response in
the IG for improving complex visual processing, QL, and FI.
Translational Relevance: Neurovisual rehabilitation of patientswith hemianopia seems
more efficient when programs combine in-office visits and customized home-based
training sessions based on real objects and simulating real-life conditions, than no treatment
or previously reported computer-screen approaches, probably because of better
stimulation of patients´ motivation and visual-processing speed brain mechanisms
Visual processing speed in hemianopia patients secondary to acquired brain injury: a new assessment methodology
Producción CientíficaBackground: There is a clinical need to identify diagnostic parameters that objectively quantify and monitor the
effective visual ability of patients with homonymous visual field defects (HVFDs). Visual processing speed (VPS) is an
objective measure of visual ability. It is the reaction time (RT) needed to correctly search and/or reach for a visual
stimulus. VPS depends on six main brain processing systems: auditory-cognitive, attentional, working memory,
visuocognitive, visuomotor, and executive. We designed a new assessment methodology capable of activating
these six systems and measuring RTs to determine the VPS of patients with HVFDs.
Methods: New software was designed for assessing subject visual stimulus search and reach times (S-RT and R-RT
respectively), measured in seconds. Thirty-two different everyday visual stimuli were divided in four complexity
groups that were presented along 8 radial visual field positions at three different eccentricities (10o, 20o, and 30o).
Thus, for each HVFD and control subject, 96 S- and R-RT measures related to VPS were registered. Three additional
variables were measured to gather objective data on the validity of the test: eye-hand coordination mistakes
(ehcM), eye-hand coordination accuracy (ehcA), and degrees of head movement (dHM, measured by a head-tracker
system). HVFD patients and healthy controls (30 each) matched by age and gender were included. Each subject
was assessed in a single visit. VPS measurements for HFVD patients and control subjects were compared for the
complete test, for each stimulus complexity group, and for each eccentricity.
Results: VPS was significantly slower (p < 0.0001) in the HVFD group for the complete test, each stimulus
complexity group, and each eccentricity. For the complete test, the VPS of the HVFD patients was 73.0% slower
than controls. They also had 335.6% more ehcMs, 41.3% worse ehcA, and 189.0% more dHMs than the controls.
Conclusions: Measurement of VPS by this new assessment methodology could be an effective tool for objectively
quantifying the visual ability of HVFD patients. Future research should evaluate the effectiveness of this novel
method for measuring the impact that any specific neurovisual rehabilitation program has for these patients
Superplastic deformation of directionally solidified nanofibrillar Al2O3-Y3Al5O12-ZrO2 eutectics
Nanofibrillar Al2O3–Y3Al5O12–ZrO2 eutectic rods were manufactured by directional solidification from the melt at high growth rates in an inert atmosphere using the laser-heated floating zone method. Under conditions of cooperative growth, the ternary eutectic presented a homogeneous microstructure, formed by bundles of single-crystal c-oriented Al2O3 and Y3Al5O12 (YAG) whiskers of ≈100 nm in width with smaller Y2O3-doped ZrO2 (YSZ) whiskers between them. Owing to the anisotropic fibrillar microstructure, Al2O3–YAG–YSZ ternary eutectics present high strength and toughness at ambient temperature while they exhibit superplastic behavior at 1600 K and above. Careful examination of the deformed samples by transmission electron microscopy did not show any evidence of dislocation activity and superplastic deformation was attributed to mass-transport by diffusion within the nanometric domains. This combination of high strength and toughness at ambient temperature together with the ability to support large deformations without failure above 1600 K is unique and shows a large potential to develop new structural materials for very high temperature structural applications
Burden of disease from exposure to secondhand smoke in children in Europe
Background Secondhand smoke (SHS) exposure at home and fetal SHS exposure during pregnancy are a major cause of disease among children. The aim of this study is quantifying the burden of disease due to SHS exposure in children and in pregnancy in 2006–2017 for the 28 European Union (EU) countries. Methods Exposure to SHS was estimated using a multiple imputation procedure based on the Eurobarometer surveys, and SHS exposure burden was estimated with the comparative risk assessment method using meta-analytical relative risks. Data on deaths and disability-adjusted life years (DALYs) were collected from National statistics and from the Global Burden of Disease Study. Results Exposure to SHS and its attributable burden stalled in 2006–2017; in pregnant women, SHS exposure was 19.8% in 2006, 19.1% in 2010, and 21.0% in 2017; in children it was 10.1% in 2006, 9.6% in 2010, and 12.1% in 2017. In 2017, 35,633 DALYs among children were attributable to SHS exposure in the EU, mainly due to low birth weight. Conclusions Comprehensive smoking bans up to 2010 contributed to reduce SHS exposure and its burden in children immediately after their implementation; however, SHS exposure still occurs, and in 2017, its burden in children was still relevant
Shortest paths on systems with power-law distributed long-range connections
We discuss shortest-path lengths on periodic rings of size L
supplemented with an average of pL randomly located long-range links whose
lengths are distributed according to P_l \sim l^{-\xpn}. Using rescaling
arguments and numerical simulation on systems of up to sites, we show
that a characteristic length exists such that for
. For small p we find
that the shortest-path length satisfies the scaling relation
\ell(r,\xpn,p)/\xi = f(\xpn,r/\xi). Three regions with different asymptotic
behaviors are found, respectively: a) \xpn>2 where , b)
1<\xpn<2 where 0<\theta_s(\xpn)<1/2 and, c) \xpn<1 where
behaves logarithmically, i.e. . The characteristic length is
of the form with \nu=1/(2-\xpn) in region b), but depends
on L as well in region c). A directed model of shortest-paths is solved and
compared with numerical results.Comment: 10 pages, 10 figures, revtex4. Submitted to PR
Capturing the essence of folding and functions of biomolecules using Coarse-Grained Models
The distances over which biological molecules and their complexes can
function range from a few nanometres, in the case of folded structures, to
millimetres, for example during chromosome organization. Describing phenomena
that cover such diverse length, and also time scales, requires models that
capture the underlying physics for the particular length scale of interest.
Theoretical ideas, in particular, concepts from polymer physics, have guided
the development of coarse-grained models to study folding of DNA, RNA, and
proteins. More recently, such models and their variants have been applied to
the functions of biological nanomachines. Simulations using coarse-grained
models are now poised to address a wide range of problems in biology.Comment: 37 pages, 8 figure
Prediction of peptide and protein propensity for amyloid formation
Understanding which peptides and proteins have the potential to undergo amyloid formation and what driving forces are responsible for amyloid-like fiber formation and stabilization remains limited. This is mainly because proteins that can undergo structural changes, which lead to amyloid formation, are quite diverse and share no obvious sequence or structural homology, despite the structural similarity found in the fibrils. To address these issues, a novel approach based on recursive feature selection and feed-forward neural networks was undertaken to identify key features highly correlated with the self-assembly problem. This approach allowed the identification of seven physicochemical and biochemical properties of the amino acids highly associated with the self-assembly of peptides and proteins into amyloid-like fibrils (normalized frequency of β-sheet, normalized frequency of β-sheet from LG, weights for β-sheet at the window position of 1, isoelectric point, atom-based hydrophobic moment, helix termination parameter at position j+1 and ΔGº values for peptides extrapolated in 0 M urea). Moreover, these features enabled the development of a new predictor (available at http://cran.r-project.org/web/packages/appnn/index.html) capable of accurately and reliably predicting the amyloidogenic propensity from the polypeptide sequence alone with a prediction accuracy of 84.9 % against an external validation dataset of sequences with experimental in vitro, evidence of amyloid formation
Highlights from the Pierre Auger Observatory
The Pierre Auger Observatory is the world's largest cosmic ray observatory.
Our current exposure reaches nearly 40,000 km str and provides us with an
unprecedented quality data set. The performance and stability of the detectors
and their enhancements are described. Data analyses have led to a number of
major breakthroughs. Among these we discuss the energy spectrum and the
searches for large-scale anisotropies. We present analyses of our X
data and show how it can be interpreted in terms of mass composition. We also
describe some new analyses that extract mass sensitive parameters from the 100%
duty cycle SD data. A coherent interpretation of all these recent results opens
new directions. The consequences regarding the cosmic ray composition and the
properties of UHECR sources are briefly discussed.Comment: 9 pages, 12 figures, talk given at the 33rd International Cosmic Ray
Conference, Rio de Janeiro 201
A search for point sources of EeV photons
Measurements of air showers made using the hybrid technique developed with
the fluorescence and surface detectors of the Pierre Auger Observatory allow a
sensitive search for point sources of EeV photons anywhere in the exposed sky.
A multivariate analysis reduces the background of hadronic cosmic rays. The
search is sensitive to a declination band from -85{\deg} to +20{\deg}, in an
energy range from 10^17.3 eV to 10^18.5 eV. No photon point source has been
detected. An upper limit on the photon flux has been derived for every
direction. The mean value of the energy flux limit that results from this,
assuming a photon spectral index of -2, is 0.06 eV cm^-2 s^-1, and no celestial
direction exceeds 0.25 eV cm^-2 s^-1. These upper limits constrain scenarios in
which EeV cosmic ray protons are emitted by non-transient sources in the
Galaxy.Comment: 28 pages, 10 figures, accepted for publication in The Astrophysical
Journa
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