Search for photon oscillations into massive particles

International audienceIn this paper, we present the final results of our experiment on photon-axion oscillations in the presence of a magnetic field, which took place at LULI (Laboratoire pour l'Utilisation des Lasers Intenses, Palaiseau, France). Our null measurement allowed us to exclude the existence of axions with inverse coupling constant $M>9.\times 10^5$ GeV for low axion masses and to improve the preceding BFRT limits by a factor 3 or more for axion masses $1.1\, \mbox{meV

Field-induced spin density wave in (TMTSF)2_2NO3_3

Interlayer magnetoresistance of the Bechgaard salt (TMTSF)$_2$NO$_3$ is investigated up to 50 teslas under pressures of a few kilobars. This compound, the Fermi surface of which is quasi two-dimensional at low temperature, is a semi metal under pressure. Nevertheless, a field-induced spin density wave is evidenced at 8.5 kbar above $\sim$ 20 T. This state is characterized by a drastically different spectrum of the quantum oscillations compared to the low pressure spin density wave state.Comment: to be published in Phys. Rev. B 71 (2005

Rising rural body-mass index is the main driver of the global obesity epidemic in adults

Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities(.)(1,2) This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity(3-6). Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55% of the global rise in mean BMI from 1985 to 2017-and more than 80% in some low- and middle-income regions-was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing-and in some countries reversal-of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories.Peer reviewe

Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants

Summary Background Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents. Methods For this pooled analysis, we used a database of cardiometabolic risk factors collated by the Non-Communicable Disease Risk Factor Collaboration. We applied a Bayesian hierarchical model to estimate trends from 1985 to 2019 in mean height and mean BMI in 1-year age groups for ages 5–19 years. The model allowed for non-linear changes over time in mean height and mean BMI and for non-linear changes with age of children and adolescents, including periods of rapid growth during adolescence. Findings We pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. In 2019, we estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and Papua New Guinea for boys; and Guatemala, Bangladesh, Nepal, and Timor-Leste for girls). In the same year, the difference between the highest mean BMI (in Pacific island countries, Kuwait, Bahrain, The Bahamas, Chile, the USA, and New Zealand for both boys and girls and in South Africa for girls) and lowest mean BMI (in India, Bangladesh, Timor-Leste, Ethiopia, and Chad for boys and girls; and in Japan and Romania for girls) was approximately 9–10 kg/m2. In some countries, children aged 5 years started with healthier height or BMI than the global median and, in some cases, as healthy as the best performing countries, but they became progressively less healthy compared with their comparators as they grew older by not growing as tall (eg, boys in Austria and Barbados, and girls in Belgium and Puerto Rico) or gaining too much weight for their height (eg, girls and boys in Kuwait, Bahrain, Fiji, Jamaica, and Mexico; and girls in South Africa and New Zealand). In other countries, growing children overtook the height of their comparators (eg, Latvia, Czech Republic, Morocco, and Iran) or curbed their weight gain (eg, Italy, France, and Croatia) in late childhood and adolescence. When changes in both height and BMI were considered, girls in South Korea, Vietnam, Saudi Arabia, Turkey, and some central Asian countries (eg, Armenia and Azerbaijan), and boys in central and western Europe (eg, Portugal, Denmark, Poland, and Montenegro) had the healthiest changes in anthropometric status over the past 3·5 decades because, compared with children and adolescents in other countries, they had a much larger gain in height than they did in BMI. The unhealthiest changes—gaining too little height, too much weight for their height compared with children in other countries, or both—occurred in many countries in sub-Saharan Africa, New Zealand, and the USA for boys and girls; in Malaysia and some Pacific island nations for boys; and in Mexico for girls. Interpretation The height and BMI trajectories over age and time of school-aged children and adolescents are highly variable across countries, which indicates heterogeneous nutritional quality and lifelong health advantages and risks

Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions

L’anonymat autobiographique est-il paradoxal ?

Un manuscrit inédit anonyme de la Bibliothèque Laurenziana de Florence intitulé Il viaggio con la mente a Gerusalemme relate le récit original d’un pèlerinage mental qu’accomplit une riche Vénitienne dans les années 1606-1607. S’inspirant de plusieurs ouvrages identifiés dans l’article, elle rédige un récit de pèlerinage qui conserve l’anonymat de son auteur. Entre exercice pénitentiel et volonté d’universalité, le texte invite à une réflexion sur les raisons de cet anonymat autobiographique

Le Centaure de Maurice de Guérin, source des Fiumi d’Ungaretti

Il n’y a pas de figure explicite du centaure dans la poésie d’Ungaretti. Pourtant, à partir de l’analyse d’un mémoire rédigé en 1914 dans le cadre de ses études à la Sorbonne, et intitulé L’inspiration poétique de Maurice de Guérin, l’article propose une lecture nouvelle de la figure de l’homme-soldat du très célèbre texte des Fiumi à la lumière du poème en prose de Guérin intitulé Le Centaure

« Mort à César ! » Naissance et diffusion du topos du Brutus tyrannicide chez les républicains florentins de la Renaissance

Tandis que Dante, dans son Purgatoire, rapproche encore la naissance du Christ d’un monde romain pacifié par César, on trouve dans le Canzoniere de Pétrarque six sonnets (44, 57, 102 : Cesare, poi che ‘l traditor d’Egitto, 103, 104 et 155 : Non fur ma’ giove et Cesare sì mossi) où, de façon très claire, le premier empereur est avant tout l’ennemi de la république à laquelle il a mis fin. D’autres textes de Pétrarque (De Viris illustrtibus, la lettre familière II, 8, etc.) tempèrent ce jugement mais l’extraordinaire succès de son œuvre poétique en italien instaure cette lecture de l’histoire de façon durable. De cela participent deux éléments déterminants à Florence : un attachement très fort aux valeurs républicaines et la longue domination des Médicis, de 1434 à 1494 tout d’abord, puis, après les épisodes républicains, de 1530 à 1737. L’exil des républicains anti-médicéens forge peu à peu, dans la droite ligne des poésies pétrarquiennes (Pétrarque était lui-même exilé et fils d’exilé), le mythe d’une tyrannie antirépublicaine dont Jules César est le modèle absolu. Telle est l’image de César que répand Machiavel dans son Prince, telle est la justification de la sculpture par Michel-Ange du buste de Brutus, le héros tyrannicide, telle est l’interprétation républicaine de l’assassinat d’Alexandre de Médicis par son cousin Lorenzo, le Lorenzaccio de Musset. Cette intervention vise donc à explorer le mythe d’un Brutus tyrannicide dans la littérature italienne, de ses origines à sa disparition progressive (fin XVIe - début XVIIe). Car l’absolutisme habile des Médicis à partir du successeur d’Alexandre conduit à l’étouffement de l’idéal républicain des Florentins. L’auteur de l’Histoire florentine, dont Sand puis Musset tirent le sujet du Lorenzaccio, est emblématique de cette puissance : l’ouvrage de Varchi n’est publié qu’au XVIIIe siècle

La Révolution de Naples : Les dix jours de Masaniello (1647)

Le point de départ de mon intervention sera l’ouvrage que j’ai publié en 2010, La Révolution de Naples. Les dix jours de Masaniello, première traduction française du texte d’Alessandro Giraffi témoin oculaire de la révolution, ou tumulte, qui en dix jours porte le miséreux Masaniello des bas-fonds de la ville à son sommet puis qui le conduit à la mort. Naples est alors la deuxième plus grande ville d’Europe et cet épisode demeure extraordinaire. Dans la lecture du récit de Giraffi, je porterai mon attention tout particulièrement à la description du peuple et aux bruits de cette révolte populaire. Par ailleurs, je compte m’appuyer aussi sur un texte inédit à ce jour à savoir un manuscrit que j’ai repéré à la Bibliothèque universitaire de Bologne : une Lettera della Rivoluzione di Napoli dont je propose la première édition critique en annexe de mon article

Péripéties éditoriales d’un “best-seller” du xvie siècle : le guide de pèlerinage de Venise au Saint-Sépulcre et au mont Sinaï

L’article porte sur un best-seller italien de la littérature de voyage intitulé Viaggio da Venezia al Santo Sepulcro et al Monte Sinai dont on connaît à ce jour une quarantaine d’éditions pour les seuls xvie et xviie siècles. Grâce à une minutieuse recherche historique et philologique, Jean-Luc Nardone remonte aux sources de ce texte anonyme et montre qu’il est une traduction de la version allemande d’un autre texte italien du xive siècle, le Viazo da Venezia de Niccolò da Poggibonsi