Influence of the multipole order of the source on the decay of an inertial wave beam in a rotating fluid

We analyze theoretically and experimentally the far-field viscous decay of a two-dimensional inertial wave beam emitted by a harmonic line source in a rotating fluid. By identifying the relevant conserved quantities along the wave beam, we show how the beam structure and decay exponent are governed by the multipole order of the source. Two wavemakers are considered experimentally, a pulsating and an oscillating cylinder, aiming to produce a monopole and a dipole source, respectively. The relevant conserved quantity which discriminates between these two sources is the instantaneous flowrate along the wave beam, which is non-zero for the monopole and zero for the dipole. For each source the beam structure and decay exponent, measured using particle image velocimetry, are in good agreement with the predictions

Le magasin de bonnes choses. La pratique des extraits de lecture de Charles d’Herculais (1770-1808)

Between history of the book, history of reading, and history of libraries, our work suggests exploring the original case of Charles d’Herculais, noble native of Dauphiné. Tireless readers, his handwriting excerpts books meet the increase of books during the eighteenth century. His "Recueils d’anecdotes" and his "Extraits de mes lectures", relate to commonplace book and adversaria book. Testimony of forty years of reading, they portray a curious man, aware of innovations of his time. Between encyclopedic curiosity and entertainment, Charles d’Herculais is interested in theater, literature, history, science… His handwriting books shows us a culture but they can also be using to write history of reading. Inextricably linked to the writing, reading evolving in private sphere, it is a remedy of the troubles of everyday life. This picture could not be complete without study his own thought writing in his "Extraits de mes lectures" forewords. Materialist and atheist, great admirer of Baron d’Holbach, he finds in this radical philosophy all the answers of the worries of the century. Although he was aware of French monarchy dysfunctions, Charles d’Herculais did not agree with revolutionaries concepts. His case raises the question of relationship between French Revolution and books.Entre histoire du livre, histoire de la lecture et histoire des bibliothèques, notre travail propose de partir à la découverte du cas original de Charles d’Herculais, noble d’origine dauphinoise. Lecteur infatigable, ses cahiers d’extraits de lecture répondent à l’augmentation vertigineuse d’imprimés au cours du XVIIIe siècle. Ses "Recueils d’anecdotes" et ses "Extraits de mes lectures" se rattachent ainsi à la tradition humaniste des recueils de lieux communs et d’adversaria. Témoins de plus de quarante années de lecture, ils dressent le portrait d’un homme curieux et au fait des nouveautés de son siècle. Entre curiosité encyclopédique et divertissement, Charles d’Herculais s’intéresse au théâtre, à la littérature, à l’histoire, aux sciences… Cette source prolifique, révélatrice d’une culture, a été également invoquée pour retracer ses pratiques de lecteur. Inextricablement liée à l’écriture, la lecture tant intensive qu’extensive évolue dans la sphère du privé, et s’érige en remède contre les maux du quotidien. Le tableau n’aurait pu être complet sans s’intéresser aux quelques réflexions proposées par notre protagoniste dans ses préfaces aux "Extraits de mes lectures". Matérialiste et athéiste convaincu, fervent admirateur du baron d’Holbach, il trouve dans cette philosophie radicale toutes les réponses aux angoisses du siècle. Malgré sa conscience des dysfonctionnements de la monarchie française et son tempérament frondeur, Charles d’Herculais n’a pas adhéré aux principes révolutionnaires. Son cas repose la question du lien entre livre et Révolution

Neutrophil Elastase Activity Imaging: Recent Approaches in the Design and Applications of Activity-Based Probes and Substrate-Based Probes

International audienceThe last few decades of protease research has con rmed that a number of important biological processes are strictly dependent on proteolysis. Neutrophil elastase (NE) is a critical protease in immune response and host defense mechanisms in both physiological and disease-associated conditions. Particularly, NE has been identi ed as a promising biomarker for early diagnosis of lung in ammation. Recent studies have shown an increasing interest in developing methods for NE activity imaging both in vitro and in vivo. Unlike anatomical imaging modalities, functional molecular imaging, including enzymatic activities, enables disease detection at a very early stage and thus constitutes a much more accurate approach. When combined with advanced imaging technologies, opportunities arise for measuring imbalanced proteolytic activities with unprecedented details. Such technologies consist in building the highest resolved and sensitive instruments as well as the most speci c probes based either on peptide substrates or on covalent inhibitors. is review outlines strengths and weaknesses of these technologies and discuss their applications to investigate NE activity as biomarker of pulmonary in ammatory diseases by imaging

Le français : une formation pour les citoyens

Les transformations de la société, la diversité des publics scolaires et les avancées de la recherche scientifique ont conduit à un renouvellement des objectifs et des méthodes dans l’enseignement du français. Dans sa contribution à la formation de l’élève et du citoyen, cet enseignement vise - notamment par le collège - à la maîtrise des discours, avec une double perception éducative et sociale, tout en donnant l’accès à la culture littéraire

Differential regulation of melatonin synthesis genes and phototransduction genes in embryonic chicken retina and cultured retinal precursor cells.

International audiencePhotoreceptor differentiation involves the activation of two specific sets of genes; those encoding the proteins of the phototransduction cascade and those encoding the enzymes of the melatonin synthesis pathway, arylalkylamine N-acetyltransferase (AANAT) and hydroxyindole O-methyltransferase (HIOMT). The purpose of the present study was to examine the conditions of AANAT and HIOMT gene activation, relative to that of selected phototransduction markers (alpha-transducin and opsins), in both in vivo and in vitro differentiating photoreceptors of the chicken retina

Wake of inertial waves of a horizontal cylinder in horizontal translation

We analyze theoretically and experimentally the wake behind a horizontal cylinder of diameter $d$ horizontally translated at constant velocity $U$ in a fluid rotating about the vertical axis at a rate $\Omega$. Using particle image velocimetry measurements in the rotating frame, we show that the wake is stabilized by rotation for Reynolds number ${\rm Re}=Ud/\nu$ much larger than in a non-rotating fluid. Over the explored range of parameters, the limit of stability is ${\rm Re} \simeq (275 \pm 25) / {\rm Ro}$, with ${\rm Ro}=U/2\Omega d$ the Rossby number, indicating that the stabilizing process is governed by the Ekman pumping in the boundary layer. At low Rossby number, the wake takes the form of a stationary pattern of inertial waves, similar to the wake of surface gravity waves behind a ship. We compare this steady wake pattern to a model, originally developed by [Johnson, J. Fluid Mech. 120, 359 (1982)], assuming a free-slip boundary condition and a weak streamwise perturbation. Our measurements show a quantitative agreement with this model for ${\rm Ro}\lesssim 0.3$. At larger Rossby number, the phase pattern of the wake is close to the prediction for an infinitely small line object. However, the wake amplitude and phase origin are not correctly described by the weak-streamwise-perturbation model, calling for an alternative model for the boundary condition at moderate rotation rate.Comment: Accepted for publication in Physical Review Fluid

What goes in and what comes out: A scoping review of regenerative agricultural practices

This scoping review examined peer-reviewed and gray literature to explore what a “no-to-low external input” statement means for regenerative agriculture. Five organic amendment inputs (compost extract, manure, mulch, biochar, food systems waste) and four land management processes (livestock management and integration, crop diversity, tillage reduction, comprehensive approach) were identified. Findings include “no-to-low external input” models arising from processes which function to displace external inputs (e.g., synthetic fertilizer). Organic amendment inputs and regenerative land management processes promote biology and improve nutrient cycling at soil, farm, and landscape scales. Regenerative agriculture overlaps with other farming practices including those associated with agroecology and conservation agriculture

The MHC class I peptide repertoire is molded by the transcriptome

Under steady-state conditions, major histocompatibility complex (MHC) I molecules are associated with self-peptides that are collectively referred to as the MHC class I peptide (MIP) repertoire. Very little is known about the genesis and molecular composition of the MIP repertoire. We developed a novel high-throughput mass spectrometry approach that yields an accurate definition of the nature and relative abundance of unlabeled peptides presented by MHC I molecules. We identified 189 and 196 MHC I–associated peptides from normal and neoplastic mouse thymocytes, respectively. By integrating our peptidomic data with global profiling of the transcriptome, we reached two conclusions. The MIP repertoire of primary mouse thymocytes is biased toward peptides derived from highly abundant transcripts and is enriched in peptides derived from cyclins/cyclin-dependent kinases and helicases. Furthermore, we found that ∼25% of MHC I–associated peptides were differentially expressed on normal versus neoplastic thymocytes. Approximately half of those peptides are derived from molecules directly implicated in neoplastic transformation (e.g., components of the PI3K–AKT–mTOR pathway). In most cases, overexpression of MHC I peptides on cancer cells entailed posttranscriptional mechanisms. Our results show that high-throughput analysis and sequencing of MHC I–associated peptides yields unique insights into the genesis of the MIP repertoire in normal and neoplastic cells

The influence of visual perspective on the somatosensory steady-state response during pain observation

The observation and evaluation of other's pain activate part of the neuronal network involved in the actual experience of pain, including those regions subserving the sensori-discriminative dimension of pain. This was largely interpreted as evidence showing that part of the painful experience can be shared vicariously. Here, we investigated the effect of the visual perspective from which other people’s pain is seen on the cortical response to continuous 25 Hz non-painful somatosensory stimulation (somatosensory steady-state response: SSSR). Based on the shared representation framework, we expected first-person visual perspective (1PP) to yield more changes in cortical activity than third-person visual perspective (3PP) during pain observation. Twenty healthy adults were instructed to rate a series of pseudo-dynamic pictures depicting hands in either painful or non-painful scenarios, presented either in 1PP (0°-45° angle) or 3PP (180° angle), while changes in brain activity was measured with a 128-electode EEG system. The ratings demonstrated that the same scenarios were rated on average as more painful when observed from the 1PP than from the 3PP. As expected from previous works, the SSSR response was decreased after stimulus onset over the left caudal part of the parieto-central cortex, contralateral to the stimulation side. Moreover, the difference between the SSSR was of greater amplitude when the painful situations were presented from the 1PP compared to the 3PP. Together, these results suggest that a visuospatial congruence between the viewer and the observed scenarios is associated with both a higher subjective evaluation of pain and an increased modulation in the somatosensory representation of observed pain. These findings are discussed with regards to the potential role of visual perspective in pain communication and empathy