Biases in the perception of self-motion during whole-body acceleration and deceleration

International audienceSeveral studies have investigated whether vestibular signals can be processed to determine the magnitude of passive body motions. Many of them required subjects to report their perceived displacements offline, i.e., after being submitted to passive displacements. Here, we used a protocol that allowed us to complement these results by asking subjects to report their introspective estimation of their displacement continuously, i.e., during the ongoing body rotation. To this end, participants rotated the handle of a manipulandum around a vertical axis to indicate their perceived change of angular position in space at the same time as they were passively rotated in the dark. The rotation acceleration (Acc) and deceleration (Dec) lasted either 1.5 s (peak of 60 • /s 2 , referred to as being " High ") or 3 s (peak of 33 • /s 2 , referred to as being " Low "). The participants were rotated either counterclockwise or clockwise, and all combinations of acceleration and deceleration were tested (i.e., AccLow-DecLow; AccLow-DecHigh; AccHigh-DecLow; AccHigh-DecHigh). The participants' perception of body rotation was assessed by computing the gain, i.e., ratio between the amplitude of the perceived rotations (as measured by the rotating manipulandum's handle) and the amplitude of the actual chair rotations. The gain was measured at the end of the rotations, and was also computed separately for the acceleration and deceleration phases. Three salient findings resulted from this experiment: (i) the gain was much greater during body acceleration than during body deceleration, (ii) the gain was greater during High compared to Low accelerations and (iii) the gain measured during the deceleration was influenced by the preceding acceleration (i.e., Low or High). These different effects of the angular stimuli on the perception of body motion can be interpreted in relation to the consequences of body acceleration and deceleration on the vestibular system and on higher-order cognitive processes

Les variations paléoenvironnementales de 1000 avant à 1000 après J.C. et la question des « optima » climatiques de l’Antiquité tardive et du Moyen Âge sur le piémont des Alpes du nord à Colletière, lac de Paladru, France

L’étude pluridisciplinaire (sédimentologie, analyse d’image à l’ordinateur, algologie, palynologie) conduite sur une séquence microlaminée de craies lacustres, prélevée sur le site archéologique médiéval immergé de Colletière (lac de Paladru, près de Grenoble), permet de reconstituer les variations hydrologiques et climatiques de 1000 avant J.C. à 1000 après J.C. sur le piémont des Préalpes occidentales françaises. Les fluctuations bathymétriques peuvent être identifiées avec un haut niveau de résolution chronologique. Sont notés trois importants mouvements régressifs, de 890-895 à 1040 ap. J.C. (entrecoupé d’un court épisode transgressif), de 500/400 à 750-700. ap. J.C., aux IXe-Xe siècles av. J.C., et une longue période à niveaux globalement hauts du lac, du Ve-VIe siècles av. J.C. au IVe-Ve siècles ap. J.C. L’influence anthropique se manifeste faiblement au Bronze Final puis disparaît totalement durant les deux Ages du Fer et la période gallo-romaine. Les témoignages d’activités humaines sur le bassin versant du lac s’amplifient entre les Ve et VIIIe siècles de notre ère, puis culminent vers l’An Mil. La confrontation des données recueillies entre Rhône et Alpes dans les milieux lacustres, fluviaux et terrestres, conduit à mieux apprécier les effets du climat sur chacun d’eux. L’amélioration climatique centrée sur 500 ap. J.C. (l’optimum de l’Antiquité tardive), et celle de l’an Mil après J.C. (l’optimum médiéval) sont plus particulièrement examinées. Celle qui couvre la fin du haut Moyen Âge, de 890 à 1040 a. J.C., se révèle plus prononcée dans ses conséquences sur les milieux continentaux, cela étant aussi le résultat des conditions climatiques qui l’ont précédé, un résultat d’effets successifs. Le rythme et l’ordre des évènements sont aussi importants que le caractère propre de chacun.A multiproxy study (sedimentology, image computer analysis, algology and palynology) led on a microlaminated lacustrine chalk cored from the medieval archaeological site of Colletière immersed on Paladru lake shore (near Grenobla) provides a palaeohydrological and palaeoclimatic reconstruction from 1000 BC to 1000 AD. Lake level fluctuations are recorded with a very high time resolution. Three important regressive levels are registered from 890-895 to 1040 AD (interrupted by a short transgressive episode), from 500/400 to 750-700 AD, in the IXth-Xth centuries BC, and a long period with high lake levels, V-VIth centuries BC to IV-Vth centuries AD. Anthropogenic signals are very weak during late Bronze age period and quite non existent during Iron age and roman period. Evidences of human activity on slopes increase between the Vth and VIIIth century AD, and are the highest around 1000 AD. Comparisons with data from regional lacustrine, fluvial and terrestrial environments allow a better understanding of climatic effects. The late Antiquity climatic optimum around 500 AD and the medieval climatic optimum are more specifically examined. The last one, from 890 to 1040 AD appears to be the most well-marked concerning its consequences on continental environments, but depending also on the pre-existing climatic conditions and on their succession. Rhythm and order of events is as important as their peculiar characteristics

Crystal structure of the cold-active aminopeptidase from Colwellia psychrerythraea, a close structural homologue of the human bifunctional leukotriene A4 hydrolase

peer reviewedThe crystal structure of a cold-active aminopeptidase (ColAP) from Colwellia psychrerythraea strain 34H has been determined, extending the number of crystal structures of the M1 metallopeptidase family to four among the 436 members currently identified. In agreement with their sequence similarity, the overall structure of ColAP displayed a high correspondence with leukotriene A4 hydrolase (LTA4H), a human bifunctional enzyme that converts leukotriene A4 (LTA4) in the potent chemoattractant leukotriene B4. Indeed, both enzymes are composed of three domains, an N-terminal saddle-like domain, a catalytic thermolysin-like domain, and a less conserved C-terminal alpha-helical flat spiral domain. Together, these domains form a deep cavity harboring the zinc binding site formed by residues included in the conserved HEXXHX(18)H motif. A detailed structural comparison of these enzymes revealed several plausible determinants of ColAP cold adaptation. The main differences involve specific amino acid substitutions, loop content and solvent exposure, complexity and distribution of ion pairs, and differential domain flexibilities. Such elements may act synergistically to allow conformational flexibility needed for an efficient catalysis in cold environments. Furthermore, the region of ColAP corresponding to the aminopeptidase active site of LTA4H is much more conserved than the suggested LTA4 substrate binding region. This observation supports the hypothesis that this region of the LTA4H active site has evolved in order to fit the lipidic substrate

Impact on construction project planning council of aqueduct Fruticas Chipaque

En los últimos años Colombia ha tenido un papel destacado en el escenario internacional por ser un país emergente económicamente, fortaleciendo significativamente los aspectos más relevantes para el desarrollo de un país. Dentro de estos factores relevantes se encuentra la construcción de infraestructurapública, que aporta grandes beneficios y brinda bienestar a la comunidad en general. Sin embargo muchas de estas obras se han visto afectadas por la mala planeación con la que se programan, incurriendo en sobrecostos que han llevado en el mejor de los casos a tiempos más largos de ejecución y en los casos más críticos al abandono de los proyectos, causando un notorio detrimento en el patrimonio de la nación y de los colombianos. Una vez revisada la información concerniente a la construcción del acueducto Fruticas del municipio de Chipaque se pudo determinar que son varios los factores que intervinieron para que su ejecución no se realizara dentro de los tiempos establecidos, siendo los más relevantes una pésima planeación de la obra dentro de su parte inicial y una gestión del riesgo inadecuada e inoportuna. El propósito fundamental de este artículo es hacer un análisis de un caso específico de un mal proyecto de construcción de infraestructura pública en Colombia, con el fin emitir algunas conclusiones, que de ser tenidas en cuenta, contribuyan a evitar que nuevos casos similares a este se presenten, afectando directamente a la economía del país y al mejoramiento de la calidad de vida de todos los colombianos.In recent years Colombia has had a prominent role on the international stage for being an economically emerging country, significantly strengthening the most important for a country's development issues. These relevant factors are the construction of public infrastructure, which provides great benefits and provides welfare to the community. However many of these works have been affected by the poor planning that are programmed with, incurring cost overruns that led to the best at longer runtimes and the most critical project abandonment cases causing a noticeable detriment to the heritage of the nation and Colombians. After reviewing the information concerning the construction of Fruticas aqueduct Township Chipaque it was determined that several factors intervened to your execution is not carried out within the established time, the most important being a lousy planning of the work within part of their initial management and inadequate and inappropriate risk. The main purpose of this paper is to analyze a specific case of a bad project to build public infrastructure in Colombia, to issue some conclusions, which if taken into account, help prevent new cases similar to this one submit, directly affecting the economy and improving the quality of life for all Colombians

Visceral, subcutaneous abdominal adiposity and liver fat content distribution in normal glucose tolerance, impaired fasting glucose and/or impaired glucose tolerance

Q1Q1Objectives: To examine the specific distribution of liver fat content, visceral and subcutaneous adiposity in normal glucose tolerance (NGT/NGT), isolated impaired fasting glucose (iIFG), isolated impaired glucose tolerance (iIGT) and combined conditions (IFG+IGT), as well as with newly diagnosed type 2 diabetes (nT2D). Design: Multicenter, international observational study: cross-sectional analysis. Subjects: Two thousand five hundred and fifteen patients (50.0% women, 54.5% non-Caucasian) without previously known diabetes were recruited from 29 countries. Abdominal fat distribution was measured by computed tomography (CT). Liver fat was estimated using the CT-liver mean attenuation. Results: Compared with NGT/NGT patients, increased visceral adiposity was found in iIFG, iIGT, IFG+IGT and nT2D; estimated liver fat progressively increased across these conditions. A one-s.d. increase in visceral adiposity was associated with an increased risk of having iIFG (men: odds ratio (OR) 1.41 (95% confidence interval (CI) 1.15–1.74), women: OR 1.62 (1.29–2.04)), iIGT (men: OR 1.59 (1.15–2.01), women: OR 1.30 (0.96–1.76)), IFG+IGT (men: OR 1.64 (1.27–2.13), women: OR 1.83 (1.36–2.48)) and nT2D (men: OR 1.80 (1.35–2.42), women: OR 1.73 (1.25–2.41)). A one-s.d. increase in estimated liver fat was associated with iIGT (men: OR 1.46 (1.12–1.90), women: OR 1.81 (1.41–2.35)), IFG+IGT (men: OR 1.42 (1.14–1.77), women: OR 1.74 (1.35–2.26)) and nT2D (men: OR 1.77 (1.40–2.27), women: OR 2.38 (1.81–3.18)). Subcutaneous abdominal adipose tissue showed an inverse relationship with nT2D in women (OR 0.63 (0.45–0.88)). Conclusions: Liver fat was associated with iIGT but not with iIFG, whereas visceral adiposity was associated with both. Liver fat and visceral adiposity were associated with nT2D, whereas subcutaneous adiposity showed an inverse relationship with nT2D in women

Forward-central two-particle correlations in p-Pb collisions at root s(NN)=5.02 TeV

Two-particle angular correlations between trigger particles in the forward pseudorapidity range (2.5 2GeV/c. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B. V.Peer reviewe

Event-shape engineering for inclusive spectra and elliptic flow in Pb-Pb collisions at root(NN)-N-S=2.76 TeV

Peer reviewe

Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions

We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Elliptic flow of muons from heavy-flavour hadron decays at forward rapidity in Pb-Pb collisions at root s(NN)=2.76TeV

The elliptic flow, v(2), of muons from heavy-flavour hadron decays at forward rapidity (2.5 <y <4) is measured in Pb-Pb collisions at root s(NN)= 2.76TeVwith the ALICE detector at the LHC. The scalar product, two- and four-particle Q cumulants and Lee-Yang zeros methods are used. The dependence of the v(2) of muons from heavy-flavour hadron decays on the collision centrality, in the range 0-40%, and on transverse momentum, p(T), is studied in the interval 3 <p(T)<10 GeV/c. A positive v(2) is observed with the scalar product and two-particle Q cumulants in semi-central collisions (10-20% and 20-40% centrality classes) for the p(T) interval from 3 to about 5GeV/c with a significance larger than 3 sigma, based on the combination of statistical and systematic uncertainties. The v(2) magnitude tends to decrease towards more central collisions and with increasing pT. It becomes compatible with zero in the interval 6 <p(T)<10 GeV/c. The results are compared to models describing the interaction of heavy quarks and open heavy-flavour hadrons with the high-density medium formed in high-energy heavy-ion collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V.Peer reviewe