989 research outputs found
New insights into the classification and nomenclature of cortical GABAergic interneurons.
A systematic classification and accepted nomenclature of neuron types is much needed but is currently lacking. This article describes a possible taxonomical solution for classifying GABAergic interneurons of the cerebral cortex based on a novel, web-based interactive system that allows experts to classify neurons with pre-determined criteria. Using Bayesian analysis and clustering algorithms on the resulting data, we investigated the suitability of several anatomical terms and neuron names for cortical GABAergic interneurons. Moreover, we show that supervised classification models could automatically categorize interneurons in agreement with experts' assignments. These results demonstrate a practical and objective approach to the naming, characterization and classification of neurons based on community consensus
New GOLD classification: Longitudinal data on group assignment
Rationale:
Little is known about the longitudinal changes associated with using the 2013 update of the multidimensional GOLD strategy for chronic obstructive pulmonary disease (COPD).
Objective:
To determine the COPD patient distribution of the new GOLD proposal and evaluate how this classification changes over one year compared with the previous GOLD staging based on spirometry only.
Methods:
We analyzed data from the CHAIN study, a multicenter observational Spanish cohort of COPD patients who are monitored annually. Categories were defined according to the proposed GOLD: FEV1%, mMRC dyspnea, COPD Assessment Test (CAT), Clinical COPD Questionnaire (CCQ), and exacerbations-hospitalizations. One-year follow-up information was available for all variables except CCQ data.
Results:
At baseline, 828 stable COPD patients were evaluated. On the basis of mMRC dyspnea versus CAT, the patients were distributed as follows: 38.2% vs. 27.2% in group A, 17.6% vs. 28.3% in group B, 15.8% vs. 12.9% in group C, and 28.4% vs. 31.6% in group D. Information was available for 526 patients at one year: 64.2% of patients remained in the same group but groups C and D show different degrees of variability. The annual progression by group was mainly associated with one-year changes in CAT scores (RR, 1.138; 95%CI: 1.074-1.206) and BODE index values (RR, 2.012; 95%CI: 1.487-2.722).
Conclusions:
In the new GOLD grading classification, the type of tool used to determine the level of symptoms can substantially alter the group assignment. A change in category after one year was associated with longitudinal changes in the CAT and BODE index
An accurate cluster selection function for the J-PAS narrow-band wide-field survey
The impending Javalambre Physics of the accelerating Universe Astrophysical Survey (J-PAS) will be the first wide-field survey of ≳ 8500 deg^2 to reach the ‘stage IV’ category. Because of the redshift resolution afforded by 54 narrow-band filters, J-PAS is particularly suitable for cluster detection in the range z80 per cent completeness and purity is M_h ∼ 5 × 10^(13) M_⊙ up to z ∼ 0.7. We also model the optical observable, M^∗_(CL)–halo mass relation, finding a non-evolution with redshift and main scatter of σM^∗_(CL)|M_h∼0.14dex down to a factor 2 lower in mass than other planned broad-band stage IV surveys, at least. For the M_h ∼ 1 × 10^(14) M_⊙ Planck mass limit, J-PAS will arrive up to z ∼ 0.85 with a σM^∗_(CL)|M_h∼0.12dex. Therefore, J-PAS will provide the largest sample of clusters and groups up to z ∼ 0.8 with a mass calibration accuracy comparable to X-ray data
Hidratos de gas marinos: ¿un recurso futuro de gas natural para Europa? M.
Los hidratos de gas son compuestos cristalinos donde una molécula de gas, principalmente metano, queda atrapada en una red de moléculas de agua en forma de hielo. La importancia de los hidratos de gas en la naturaleza es muy alta ya que constituye una fuente alternativa de energía y a su vez juegan un papel importante en el delicado equilibrio del clima a nivel global y en los riesgos geológicos en el ámbito marino. La acción COST MIGRATE está diseñada con el fin de integrar la experiencia de un gran número de grupos de investigación europeos y agentes del sector para promover el desarrollo de conocimientos multidisciplinarios sobre el potencial de los hidratos de gas como fuente de energía en Europa. Dos de los objetivos de esta acción son realizar un inventario europeo de hidratos de gas explotables y evaluar los riesgos ambientales. En este trabajo se muestran los principales indicios de hidratos de gas en los márgenes europeos incluida la Península Ibérica, con una primera aproximación sobre el espesor y situación de la zona de estabilidad de hidratos de gas en el margen Ibérico.Gas hydrates are crystalline compounds where a molecule of gas, mainly methane, is trapped in a cage of icewater molecules. The importance of gas hydrates in nature is very high because it is an alternative source of energy and play a major role in the delicate balance of the global climate and in the marine geological risks. MIGRATE COST action is designed to integrate the experience of a large number of European research groups and industrial players to promote the development of multidisciplinary knowledge on the potential of gas hydrates as energy resource in Europe. Two of the objectives of the action aim to estimate the European inventory of exploitable gas hydrates and to assess environmental risks. In this work we show the occurrences of gas hydrates described in European margins including the
Iberian Peninsula, with a first approximation on the thickness and location of the area of stability of gas hydrates in the Iberian margin.COST Action ES1405 (MIGRATE)Versión del edito
The membrane-spanning 4-domains, subfamily A (MS4A) gene cluster contains a common variant associated with Alzheimer's disease
Background\ud
In order to identify novel loci associated with Alzheimer's disease (AD), we conducted a genome-wide association study (GWAS) in the Spanish population.\ud
\ud
Methods\ud
We genotyped 1,128 individuals using the Affymetrix Nsp I 250K chip. A sample of 327 sporadic AD patients and 801 controls with unknown cognitive status from the Spanish general population were included in our initial study. To increase the power of the study, we combined our results with those of four other public GWAS datasets by applying identical quality control filters and the same imputation methods, which were then analyzed with a global meta-GWAS. A replication sample with 2,200 sporadic AD patients and 2,301 controls was genotyped to confirm our GWAS findings.\ud
\ud
Results\ud
Meta-analysis of our data and independent replication datasets allowed us to confirm a novel genome-wide significant association of AD with the membrane-spanning 4-domains subfamily A (MS4A) gene cluster (rs1562990, P = 4.40E-11, odds ratio = 0.88, 95% confidence interval 0.85 to 0.91, n = 10,181 cases and 14,341 controls).\ud
\ud
Conclusions\ud
Our results underscore the importance of international efforts combining GWAS datasets to isolate genetic loci for complex diseases
Charge separation relative to the reaction plane in Pb-Pb collisions at TeV
Measurements of charge dependent azimuthal correlations with the ALICE
detector at the LHC are reported for Pb-Pb collisions at TeV. Two- and three-particle charge-dependent azimuthal correlations in
the pseudo-rapidity range are presented as a function of the
collision centrality, particle separation in pseudo-rapidity, and transverse
momentum. A clear signal compatible with a charge-dependent separation relative
to the reaction plane is observed, which shows little or no collision energy
dependence when compared to measurements at RHIC energies. This provides a new
insight for understanding the nature of the charge dependent azimuthal
correlations observed at RHIC and LHC energies.Comment: 12 pages, 3 captioned figures, authors from page 2 to 6, published
version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/286
Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at = 5.02 TeV
Two-particle angular correlations between unidentified charged trigger and
associated particles are measured by the ALICE detector in p-Pb collisions at a
nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum
range 0.7 5.0 GeV/ is examined,
to include correlations induced by jets originating from low
momen\-tum-transfer scatterings (minijets). The correlations expressed as
associated yield per trigger particle are obtained in the pseudorapidity range
. The near-side long-range pseudorapidity correlations observed in
high-multiplicity p-Pb collisions are subtracted from both near-side
short-range and away-side correlations in order to remove the non-jet-like
components. The yields in the jet-like peaks are found to be invariant with
event multiplicity with the exception of events with low multiplicity. This
invariance is consistent with the particles being produced via the incoherent
fragmentation of multiple parton--parton scatterings, while the yield related
to the previously observed ridge structures is not jet-related. The number of
uncorrelated sources of particle production is found to increase linearly with
multiplicity, suggesting no saturation of the number of multi-parton
interactions even in the highest multiplicity p-Pb collisions. Further, the
number scales in the intermediate multiplicity region with the number of binary
nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/161
Sub-femto-g free fall for space-based gravitational wave observatories: LISA pathfinder results
We report the first results of the LISA Pathfinder in-flight experiment. The results demonstrate that two free-falling reference test masses, such as those needed for a space-based gravitational wave observatory like LISA, can be put in free fall with a relative acceleration noise with a square root of the power spectral density of 5.2 ± 0.1 fm s−2/√Hz or (0.54 ± 0.01) × 10−15 g/√Hz, with g the standard gravity, for frequencies between 0.7 and 20 mHz. This value is lower than the LISA Pathfinder requirement by more than a factor 5 and within a factor 1.25 of the requirement for the LISA mission, and is compatible with Brownian noise from viscous damping due to the residual gas surrounding the test masses. Above 60 mHz the acceleration noise is dominated by interferometer displacement readout noise at a level of (34.8 ± 0.3) fm/√Hz, about 2 orders of magnitude better than requirements. At f ≤ 0.5 mHz we observe a low-frequency tail that stays below 12 fm s−2/√Hz down to 0.1 mHz. This performance would allow for a space-based gravitational wave
observatory with a sensitivity close to what was originally foreseen for LISA
Multi-particle azimuthal correlations in p-Pb and Pb-Pb collisions at the CERN Large Hadron Collider
Measurements of multi-particle azimuthal correlations (cumulants) for charged
particles in p-Pb and Pb-Pb collisions are presented. They help address the
question of whether there is evidence for global, flow-like, azimuthal
correlations in the p-Pb system. Comparisons are made to measurements from the
larger Pb-Pb system, where such evidence is established. In particular, the
second harmonic two-particle cumulants are found to decrease with multiplicity,
characteristic of a dominance of few-particle correlations in p-Pb collisions.
However, when a gap is placed to suppress such correlations,
the two-particle cumulants begin to rise at high-multiplicity, indicating the
presence of global azimuthal correlations. The Pb-Pb values are higher than the
p-Pb values at similar multiplicities. In both systems, the second harmonic
four-particle cumulants exhibit a transition from positive to negative values
when the multiplicity increases. The negative values allow for a measurement of
to be made, which is found to be higher in Pb-Pb collisions at
similar multiplicities. The second harmonic six-particle cumulants are also
found to be higher in Pb-Pb collisions. In Pb-Pb collisions, we generally find
which is indicative of a Bessel-Gaussian
function for the distribution. For very high-multiplicity Pb-Pb
collisions, we observe that the four- and six-particle cumulants become
consistent with 0. Finally, third harmonic two-particle cumulants in p-Pb and
Pb-Pb are measured. These are found to be similar for overlapping
multiplicities, when a gap is placed.Comment: 25 pages, 11 captioned figures, 3 tables, authors from page 20,
published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/87
A note on comonotonicity and positivity of the control components of decoupled quadratic FBSDE
In this small note we are concerned with the solution of Forward-Backward
Stochastic Differential Equations (FBSDE) with drivers that grow quadratically
in the control component (quadratic growth FBSDE or qgFBSDE). The main theorem
is a comparison result that allows comparing componentwise the signs of the
control processes of two different qgFBSDE. As a byproduct one obtains
conditions that allow establishing the positivity of the control process.Comment: accepted for publicatio
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