Les sociétés savantes au XIXe siècle, une sociabilité exceptionnelle

Réflexion autour des enjeux de la sociabilité érudite développée par les sociétés savantes toulousaines au XIxe siècle

Influence of Controlled Breathing on Cerebrovascular Control During Upright Tilt

Arterial pressures oscillate with the frequency of respiration, and these oscillations are translated directly to the cerebrovasculature. For this reason, intrinsic cerebrovascular control is assessed at the low frequency (LF; .07-.2 Hz). When humans breathe spontaneously, it is possible that breathing frequency encroaches on these non-respiratory rhythms, thereby confounding the interpretation of intrinsic cerebrovascular control. PURPOSE: To test the hypothesis that controlled breathing (CB) decreases, and spontaneous breathing (SB) increases the reliance of cerebral blood velocity on arterial pressure within the LF range in both the supine and upright postures. METHODS: We recorded ECG, finger arterial pressure (Finometer), transcranial Doppler ultrasound of the middle cerebral artery, and end-tidal CO₂ in 20 healthy male volunteers (24±2 yrs). Ten subjects breathed in time to a metronome set at a pace of 15 breaths/min (CB), and ten subjects breathed spontaneously (SB). Both groups were studied in the supine and head-up tilt (HUT) positions for 5-min. Reliance of mean cerebral blood velocity (CBVmean) on mean arterial pressure (MAP) was assessed over the LF with cross-spectral coherence analysis (COH). RESULTS: Respiratory rates were not different between CB and SB during supine (p=.86), but were lower for SB compared with CB during HUT (11.7±.7 vs. 14.8±.1; p\u3c.001). End-tidal CO₂ was decreased by CB during both supine and HUT (p\u3c.05). CBVmean was decreased with CB during supine (p=.04), but was similar between CB and SB during HUT (p=.14). Neither LFMAP nor LFCBVmean oscillations were different in the supine position (p\u3e.6), but were increased (with a trend for LFMAP) with SB during HUT (p=.003 for LF CBVmean and p=.09 for LFMAP). COH was not different in the supine position between CB and SB (.42±.05 for CB and .61±.06 SB; p=.13), but was lower for CB in the HUT position (.55±.05 for CB and .78±.08 for SB; p=.02). CONCLUSION: Reliance of CBVmean on MAP is increased in the LF range when subjects breathe spontaneously during HUT. We attribute changes in COH during HUT to entrainment of respiratory-mediated arterial pressure fluctuations on the cerebrovasculature. However, the potential confounding influence of hypocapnia warrants further investigation

Galletas con grasas cero trans a base de soja formuladas usando una red neuronal artificial.

This study applied Artificial Neural Network (ANN) technology to formulate zero trans fat blends derived from soybeans and to evaluate their performance when applied to the processing of sweet laminated biscuits. For the formulation of the blends, two interesterified soybean fats and soybean oil were used as bases. They were characterized in terms of melting point, solid fat content and fatty acid composition; and the biscuits produced were analyzed for their technological (dimensions, mass, volume, expansion, instrumental color and texture, moisture gradient and cracking) and physicochemical characteristics (total fat and moisture contents, water activity and fatty acid composition). It was possible to verify the use of ANN to develop zero trans fats derived from soybeans for application in sweet laminated biscuits, which represents an operational and financial advantage. Moreover, we showed the viability of using soybean fats/oil, raw materials of greater availability and lower cost, for the production of biscuits.Este estudio aplic? la tecnolog?a de Redes Neuronales Artificiales (RNA) para formular mezclas de grasas cero trans derivadas de soja y evaluar su papel cuando se usan en el procesamiento de galletas dulces laminadas. Para la formulaci?n de las mezclas se usaron como base dos grasas de soja interesterificadas as? como aceite de soja. Se caracterizaron en t?rminos de punto de fusi?n, contenido de grasa s?lida y composici?n de ?cidos grasos, y a las galletas se les determin? sus caracter?sticas tecnol?gicas (dimensiones, masa, volumen, color, textura, gradiente de humedad as? como otros controles) y fisicoqu?micas (contenidos de grasa total, humedad, actividad de agua y composici?n de ?cidos grasos). Fue posible verificar el uso de RNA para desarrollar grasas cero trans derivadas de soja, para su aplicaci?n en galletas dulces laminadas, lo que representa una ventaja operativa y financiera. Adem?s, mostramos la viabilidad de usar grasas/aceite de soja, materias primas de mayor disponibilidad y menor costo, para la producci?n de galletas

The SLUGGS Survey: stellar kinematics, kinemetry and trends at large radii in 25 early-type galaxies

Due to longer dynamical time-scales, the outskirts of early-type galaxies retain the footprint of their formation and assembly. Under the popular two-phase galaxy formation scenario, an initial in situ phase of star formation is followed by minor merging and accretion of ex situ stars leading to the expectation of observable transitions in the kinematics and stellar populations on large scales. However, observing the faint galactic outskirts is challenging, often leaving the transition unexplored. The large-scale, spatially resolved stellar kinematic data from the SAGES Legacy Unifying Galaxies and GlobularS (SLUGGS) survey are ideal for detecting kinematic transitions. We present kinematic maps out to 2.6 effective radii on average, kinemetry profiles, measurement of kinematic twists and misalignments, and the average outer intrinsic shape of 25 SLUGGS galaxies. We find good overall agreement in the kinematic maps and kinemetry radial profiles with literature. We are able to confirm significant radial modulations in rotational versus pressure support of galaxies with radius so that the central and outer rotational properties may be quite different. We also test the suggestion that galaxies may be more triaxial in their outskirts and find that while fast rotating galaxies were already shown to be axisymmetric in their inner regions, we are unable to rule out triaxiality in their outskirts.We compare our derived outer kinematic information to model predictions from a two-phase galaxy formation scenario. We find that the theoretical range of local outer angular momentum agrees well with our observations, but that radial modulations are much smaller than predicted

LCA case study: comparison between independent and coproduction pathways for the production of ethyl and n-butyl acetates

The production of ethyl acetate and n-butyl acetate was investigated through two different pathways: either by independent reactions or by coproduction. In the coproduction pathway, the n-butyl acetate was produced by reusing the by-products of the synthesis of ethyl acetate. This study provides a comparison of the environmental impacts of these two pathways using a life cycle assessment (LCA). A discussion about the use of LCA on chemicals and its challenges was also developed

Single-dose cholera vaccine in response to an outbreak in Zambia

Producción CientíficaKilled oral cholera vaccines (OCVs) are part of the standard response package to a cholera outbreak, although the two-dose regimen of vaccines that has been prequalified by the World Health Organization (WHO) poses challenges to timely and efficient reactive vaccination campaigns.1 Recent data suggest that the first dose alone provides short-term protection, similar to that of two doses, which may largely dictate the effect of OCVs during epidemic

First results from the JWST Early Release Science Program Q3D: Ionization cone, clumpy star formation and shocks in a z=3z=3 extremely red quasar host

Massive galaxies formed most actively at redshifts $z=1-3$ during the period known as `cosmic noon.' Here we present an emission-line study of an extremely red quasar SDSSJ165202.64+172852.3 host galaxy at $z=2.94$, based on observations with the Near Infrared Spectrograph (NIRSpec) integral field unit (IFU) on board JWST. We use standard emission-line diagnostic ratios to map the sources of gas ionization across the host and a swarm of companion galaxies. The quasar dominates the photoionization, but we also discover shock-excited regions orthogonal to the ionization cone and the quasar-driven outflow. These shocks could be merger-induced or -- more likely, given the presence of a powerful galactic-scale quasar outflow -- these are signatures of wide-angle outflows that can reach parts of the galaxy that are not directly illuminated by the quasar. Finally, the kinematically narrow emission associated with the host galaxy presents as a collection of 1 kpc-scale clumps forming stars at a rate of at least 200 $M_{\odot}$ yr$^{-1}$. The ISM within these clumps shows high electron densities, reaching up to 3,000 cm$^{-3}$ with metallicities ranging from half to a third solar with a positive metallicity gradient and V band extinctions up to 3 magnitudes. The star formation conditions are far more extreme in these regions than in local star-forming galaxies but consistent with that of massive galaxies at cosmic noon. JWST observations reveal an archetypical rapidly forming massive galaxy undergoing a merger, a clumpy starburst, an episode of obscured near-Eddington quasar activity, and an extremely powerful quasar outflow simultaneously.Comment: 19 pages, 8 figures. Accepted for publication in Ap

First results from the JWST Early Release Science Program Q3D: The Warm Ionized Gas Outflow in z ~ 1.6 Quasar XID 2028 and its Impact on the Host Galaxy

Quasar feedback may regulate the growth of supermassive black holes, quench coeval star formation, and impact galaxy morphology and the circumgalactic medium. However, direct evidence for quasar feedback in action at the epoch of peak black hole accretion at z ~ 2 remains elusive. A good case in point is the z = 1.6 quasar WISEA J100211.29+013706.7 (XID 2028) where past analyses of the same ground-based data have come to different conclusions. Here we revisit this object with the integral field unit of the Near Infrared Spectrograph (NIRSpec) on board the James Webb Space Telescope (JWST) as part of Early Release Science program Q3D. The excellent angular resolution and sensitivity of the JWST data reveal new morphological and kinematic sub-structures in the outflowing gas plume. An analysis of the emission line ratios indicates that photoionization by the central quasar dominates the ionization state of the gas with no obvious sign for a major contribution from hot young stars anywhere in the host galaxy. Rest-frame near-ultraviolet emission aligned along the wide-angle cone of outflowing gas is interpreted as a scattering cone. The outflow has cleared a channel in the dusty host galaxy through which some of the quasar ionizing radiation is able to escape and heat the surrounding interstellar and circumgalactic media. The warm ionized outflow is not powerful enough to impact the host galaxy via mechanical feedback, but radiative feedback by the AGN, aided by the outflow, may help explain the unusually small molecular gas mass fraction in the galaxy host.Comment: 17 pages, 9 figures, accepted for publication in The Astrophysical Journa