Comments about birefringence dispersion, with group and phase birefringence measurements in polarization-maintaining fibers

A recent JEOS-RP publication proposed Comments about Dispersion of Light Waves, and we present here complementary comments for birefringence dispersion in polarization-maintaining (PM) fibers, and for its measurement techniques based on channeled spectrum analysis. We start by a study of early seminal papers, and we propose additional explanations to get a simpler understanding of the subject. A geometrical construction is described to relate phase birefringence to group birefringence, and it is applied to the measurement of several kinds of PM fibers using stress-induced photo-elasticity, or shape birefringence. These measurements confirm clearly that the difference between group birefringence and phase birefringence is limited to 15–20% in stress-induced PM fibers (bow-tie, panda, or tiger-eye), but that it can get up to a 3-fold factor with an elliptical-core (E-core) fiber. There are also surprising results with solid-core micro-structured PM fibers, that are based on shape birefringence, as E-core fibers

Évolution de la contribution française à l'upgrade de LHCb

Ce document décrit l'évolution de la contribution française à l'upgrade de LHCb. Il s'inscrit dans le prolongement de la Lettre d'Intention [1], du Framework TDR [2], du document soumis au Conseil scientifique de l'IN2P3 le 21 juin 2012 [3], et des Technical Design Reports soumis au LHCC en novembre 2013 [4, 5]. Ces derniers concernent le détecteur de vertex et les détecteurs utilisés dans l'identification des particules. La contribution française s'est cristallisée autour de quatre grands projets : l'électronique front-end des calorimètres et du trajectographe à fibres scintillantes, le système de déclenchement de premier niveau et la carte de lecture à 40MHz commune à l'ensemble des sous-systèmes. Dans ce document nous décrivons les contributions envisagées et les ressources nécessaires pour mener à bien ces projets

PIRATA: A Sustained Observing System for Tropical Atlantic Climate Research and Forecasting

Prediction and Research Moored Array in the Tropical Atlantic (PIRATA) is a multinational program initiated in 1997 in the tropical Atlantic to improve our understanding and ability to predict ocean-atmosphere variability. PIRATA consists of a network of moored buoys providing meteorological and oceanographic data transmitted in real time to address fundamental scientific questions as well as societal needs. The network is maintained through dedicated yearly cruises, which allow for extensive complementary shipboard measurements and provide platforms for deployment of other components of the Tropical Atlantic Observing System. This paper describes network enhancements, scientific accomplishments and successes obtained from the last 10 years of observations, and additional results enabled by cooperation with other national and international programs. Capacity building activities and the role of PIRATA in a future Tropical Atlantic Observing System that is presently being optimized are also described

Murchison Widefield Array limits on radio emission from Antares neutrino events

We present a search, using the Murchison Widefield Array (MWA), for electromagnetic (EM) counterparts to two candidate high-energy neutrino events detected by the ANTARES neutrino telescope in 2013 November and 2014 March. These events were selected by ANTARES because they are consistent, within 0°.4, with the locations of galaxies within 20 Mpc of Earth. Using MWA archival data at frequencies between 118 and 182 MHz, taken ~20 days prior to, at the same time as, and up to a year after the neutrino triggers, we look for transient or strongly variable radio sources that are consistent with the neutrino positions. No such counterparts are detected, and we set a 5s upper limit for low-frequency radio emission of ~1037 erg s-1 for progenitors at 20 Mpc. If the neutrino sources are instead not in nearby galaxies, but originate in binary neutron star coalescences, our limits place the progenitors at z 0.2. While it is possible, due to the high background from atmospheric neutrinos, that neither event is astrophysical, the MWA observations are nevertheless among the first to follow up neutrino candidates in the radio, and illustrate the promise of wide-field instruments like MWA for detecting EM counterparts to such events

Sperm whale long-range echolocation sounds revealed by ANTARES, a deep-sea neutrino telescope

[EN] Despite dedicated research has been carried out to adequately map the distribution of the sperm whale in the Mediterranean Sea, unlike other regions of the world, the species population status is still presently uncertain. The analysis of two years of continuous acoustic data provided by the ANTARES neutrino telescope revealed the year-round presence of sperm whales in the Ligurian Sea, probably associated with the availability of cephalopods in the region. The presence of the Ligurian Sea sperm whales was demonstrated through the real-time analysis of audio data streamed from a cabled-to- shore deep-sea observatory that allowed the hourly tracking of their long-range echolocation behaviour on the Internet. Interestingly, the same acoustic analysis indicated that the occurrence of surface shipping noise would apparently not condition the foraging behaviour of the sperm whale in the area, since shipping noise was almost always present when sperm whales were acoustically detected. The continuous presence of the sperm whale in the region confirms the ecological value of the Ligurian sea and the importance of ANTARES to help monitoring its ecosystemsThe authors acknowledge the financial support of the funding agencies: Centre National de la Recherche Scientifique (CNRS), Commissariat a lenergie atomique et aux energies alternatives (CEA), la Commission Europeenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), IdEx program and UnivEarthS Labex program at Sorbonne Paris Cite (ANR-10-LABX-0023 and ANR-11-IDEX-0005-02), Region Ile-de-France (DIM-ACAV), Region Alsace (contrat CPER), Region Provence-Alpes-Cote d'Azur, Departement du Var and Ville de La Seyne-sur-Mer, France; Bundesministerium fur Bildung und Forschung (BMBF), Germany; Istituto Nazionale di Fisica Nucleare (INFN), Italy; Stichting voor Fundamenteel Onderzoek der Materie (FOM), Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; Council of the President of the Russian Federation for young scientists and leading scientific schools supporting grants, Russia; National Authority for Scientific Research (ANCS), Romania; Ministerio de Economia y Competitividad (MINECO), Prometeo and Grisolia programs of Generalitat Valenciana and MultiDark, Spain; Agence de l'Oriental and CNRST, Morocco. We also acknowledge the technical support of Ifremer, AIM and Foselev Marine for the sea operation and the CC-IN2P3 for the computing facilitiesAndre, M.; Caballé, A.; Van Der Schaar, M.; Solsona, A.; Houégnigan, L.; Zaugg, S.; Sanchez, AM.... (2017). Sperm whale long-range echolocation sounds revealed by ANTARES, a deep-sea neutrino telescope. Scientific Reports. 7:1-12. https://doi.org/10.1038/srep45517S1127Aguilar, J. A. et al. ANTARES: the first undersea neutrino telescope. Nucl Inst and Met Phys Res A. 656, 11–38 (2011a).Aguilar, J. A. et al. AMADEUS - The Acoustic Neutrino Detection Test System of the ANTARES Deep-Sea Neutrino Telescope -. Nucl Inst and Met Phys Res A. 626–627, 128–143 (2011b).Ruhl, H. et al. Societal need for improved understanding of climate change, anthropogenic impacts, and geo-hazard warning drive development of ocean observatories in European Seas. Prog Oceanog. 91, 1–33 (2011).Tamburini, C. et al. Deep-sea bioluminescence blooms after dense water formation at the ocean surface. PLoS One. 8(7), e67523. doi: 10.1371/journal.pone.0067523 (2013).Van Haren, H. et al. Acoustic and optical variations during rapid downward motion episodes in the deep North Western Mediterranean. Deep Sea Res I. 58, 875–884 (2011).Van der Graaf, A. J. et al. European Marine Strategy Framework Directive - Good Environmental Status (MSFD GES): Report of the Technical Subgroup on Underwater noise and other forms of energy (2012).Hatch, L. T., Clark, C. W., Van Parijs, S. M., Frankel, A. S. & Ponirakis, D. W. Quantifying Loss of Acoustic Communication Space for Right Whales in and around a U.S. National Marine Sanctuary. Conserv Biol. 26, 983–994 (2012).André, M. et al. Low-frequency sounds induce acoustic trauma in cephalopods. Front. Ecol. Environ. 9, 489–493 (2011).Solé, M. et al. Does exposure to noise from human activities compromise sensory information from cephalopod statocysts? Deep Sea Res. II. 95, 160–181 (2013).Solé, M. et al. Ultrastructural damage of Loligo vulgaris and Illex coindetii statocysts after low frequency sound exposure. PLoS One 8(10), e78825. doi: 10.1371/journal.pone.0078825 (2013).André, M. et al. Listening to the Deep: Live monitoring of ocean noise and cetacean acoustic signals. Mar Pollut Bull. 63, 18–26 (2011).Whitehead, H. Sperm whales: social evolution in the ocean(The University of Chicago Press, Chicaho, 2003).Mohl, B., Wahlberg, M., Madsen, P. T., Heerfordt, A. & Lund, A. The monopulsed nature of sperm whale clicks. J Acous Soc Am. 114, 1143–1154 (2003).André, M., Johansson, T., Delory, E. & van der Schaar, M. Foraging on squid: the sperm whale mid-range sonar. Jour Mar Biol Assoc. 87, 59–67 (2007).Madsen, P., Wahlberg, M. & Møhl, B. Male sperm whale (Physeter macrocephalus) acoustics in a high-latitude habitat: implications for echolocation and communication. Behav Ecol Sociobiol. 53, 31, doi: 10.1007/s00265-002-0548-1 (2002).Gannier, A., Drouot, V. & Goold, J. C. Distribution and relative abundance of sperm whales in the Mediterranean Sea . Mar Ecol Prog Ser. 243, 281–293 (2000).Drouot, V., Gannier, A. & Gould, J. C. Summer social distribution of sperm whales in the Mediterranean Sea. J Mar Biol Ass. 84, 675–680 (2004).Pavan, G. et al. G. Short Term and Long Term Bioacoustic Monitoring of the Marine Environment. Results from NEMO ONDE Experiment and Way Ahead in Computational bioacoustics for assessing biodiversity . Proceedings of the International Expert meeting on IT-based detection of bioacoustical patterns(ed. Frommolt, K. H., Rolf Bardeli, R. & Clausen, M. ) 7–14 (Federal Agency for Nature Conservation, Bonn, 2008).Frantzis, A. et al. Sperm whale presence off South-West Crete, Eastern Mediterranean Sea in Proc. 13th Ann. Conf. ECS. 214–217 (Eur Res Cet, Valencia, 1999).Notarbartolo-Di-Sciara, G. Sperm whales, Physeter macrocephalus, in the Mediterranean Sea: a summary of status, threats, and conservation recommendations. Aquatic Conserv. Mar. Freshw. Ecosyst. 24, 4–10. doi: 10.1002/aqc.2409 (2014).Pace, D. S., Mussi, B., Gordon, J. C. D. & Würtz, M. Ecology, Behaviour and Conservation of Sperm Whale in the Mediterranean Sea in Aquatic Conserv . Mar. Freshw. Ecosyst. 24 (ed. Wiley, J. ) 1–118 (Wiley Online library, 2014).Rendell, L. E. & Frantzis, A. Mediterranean sperm whales, Physeter macrocephalus: the precarious state of a lost tribe In Medit. Mar. Mam. Ecol. Cons. 75 (ed. Notarbartolo di Sciara, G., Podestà, M. P. & Curry, B. E. ) 37–74, doi: 10.1016/bs.amb.2016.08.001 (Advances in Marine Biology, Academic Press/Elsevier, 2016).Di Natale, A. & Notarbartolo di Sciara, G. A review of the passive fishing nets and trap fisheries in the Mediterranean Sea and of the cetacean bycatch In Gillnets and cetaceans(ed. Perrin, W. F., Donovan, G. P. & Barlow, J. ) 189–202 (Rep Int Whal Comm, 1994).Jaquet, N., Whitehead, H. & Lewis, M. Relationship between sperm whale distribution and primary productivity over large spatial scale in the Pacific ocean. Eur Res Cet. 9, 188–192 (1995).Millot, C. Circulation in the Western Mediterranean Sea. Oceanol Acta. 10, 143–150 (1987).Morel, A. & André, J. M. Pigment distribution and primary production in the Western Mediterranean as derived from coastal zone color scanner observations. J Geophy Res. 96, 2685–12698 (1991).Crépon, M., Wald, L. & Monget, J. M. Low-frequency waves in the Ligurian Sea during December 1977. J Geophys Res. 87, 595–600 (1982).Prieur, L. & Sathyendranath, S. An optical classification of coastal and oceanic waters based on the specific spectral absorption curves of phytoplankton pigments, dissolved organic matter, and other particulate materials. Limnol Oceanogr. 26, 671–89 (1981).Kawakami, T. A review of sperm whale food. Sci Rep Whales Res Inst. 32, 199–218 (1980).Roper, C. F. E. & Young, R. E. Vertical distribution of pelagic cephalopods. Smithson Contrib Zool. 209, 1–51 (1975).Matsushita, T. Daily rhythmic activity of the sperm whales in the Antarctic. Bull Jpn Soc Sci Fish. 20, 770–73 (1955).Zaugg, S. et al. Real-time acoustic classification of sperm whale clicks and shipping impulses from deep-sea observatories. Appl Acoust. 71(11), 1011–1019 (2010).Nelder, J. & Wedderburn, R. Generalized linear models. J R Stat Soc. 135, 370–384 (1972)

Comments about dispersion of light waves

Dispersion of light waves is well known, but the subject deserves some comments. Certain classical equations do not fully respect causality; as an example, group velocity vg is usually given as the first derivative of the angular frequency ω with respect to the angular spatial frequency km (or wavenumber) in the medium, whereas it is km that depends on ω. This paper also emphasizes the use of phase index n and group index ng, as inverse of their respective velocities, normalized to 1/c, the inverse of free-space light velocity. This clarifies the understanding of dispersion equations: group dispersion parameter D is related to the first derivative of ng with respect to wavelength λ, whilst group velocity dispersion GVD is also related to the first derivative of ng, but now with respect to angular frequency ω. One notices that the term second order dispersion does not have the same meaning with λ, or with ω. In addition, two original and amusing geometrical constructions are proposed; they simply derive group index ng from phase index n with a tangent, which helps to visualize their relationship. This applies to bulk materials, as well as to optical fibers and waveguides, and this can be extended to birefringence and polarization mode dispersion in polarization-maintaining fibers or birefringent waveguides

Programme de remédiation intensive chez des lecteurs dyslexiques de 8 à 13 ans

International audienceLes études menées pour valider des méthodes de remédiation de la dyslexie développementale (DD) sont généralement fondées sur l'hypothèse d'une cause unique liée à des altérations soit du traitement phonologique, soit du traitement visuo-attentionnel, soit de l'intégration intermodalitaire. Or, de nombreuses études montrent que la cause de la DD est multifactorielle et que la majorité des lecteurs dyslexiques (LD) présentent des déficits cognitifs sous-jacents dans plusieurs domaines. L'originalité de cette intervention est de proposer une approche de remédiation à la fois phonologique, visuo-attentionnelle et intermodalitaire en proposant des programmes d’entraînement systématiques, individualisés et intensifs pendant 6 mois.Cette étude longitudinale multicentrique, randomisée et croisée est menée en trois phases auprès de 59 LD âgés de 8 à 13 ans. Lors de la première phase, les participants bénéficient de consultations hebdomadaires de rééducation orthophonique sans entraînement intensif pendant deux mois. Lors de la deuxième phase, ils sont répartis en deux groupes et bénéficient, en plus de leur suivi hebdomadaire, de trois types d'interventions intensives informatisées, d’une durée de deux mois chacune. L'ordre des deux premières interventions (phonologique et visuo-attentionnelle) est contrebalancé entre les deux groupes puis suivie par une intervention intermodalitaire. Lors de la troisième phase, les interventions intensives sont arrêtées et les consultations hebdomadaires de rééducation orthophonique maintenues pendant deux mois.Des résultats préliminaires confirment des effets significatifs positifs sur les compétences en lecture qui se maintiennent après l’arrêt de l’intervention. Ce programme de remédiation multimodal pourrait représenter une réponse thérapeutique efficace fondée sur les preuves dans le traitement de la DD

First contribution of the excavation and chronostratigraphic study of the Ruways 1 Neolithic shell midden (Oman) in terms of Neolithisation, palaeoeconomy, social‐environmental interactions and site formation processes

International audienceThe NeoArabia project tries to understand how environmental, social, economic and technological factors work in concert to influence settlement and abandonment along a latitudinal transect of 1200 km from UAE to southern Oman. This region was affected by wide north–south variations in the Indo‐Arabian monsoon, marine upwelling activity and eustatic variations in the Mid‐Holocene. On the local settlement scale, this transect is based on fine stratigraphic excavations and permits the reconstruction of the site formation processes and site catchment analysis. A large number of studies have been conducted on the Ruways‐1 site, focusing on a deep stratified sequence corresponding to three millennia of occupation. These studies include on‐site climate‐environmental signal analysis, local palaeogeography and environmental reconstruction, reservoir effect studies, typo‐technological studies, palaeoeconomic strategies, anthropological studies, sclerochronological studies and, finally, site formation processes, the understanding of which makes it possible to explain the potential and limits of the archaeological excavation. The first results confirm the richness of these archaeological archives for documenting the socio‐environmental dynamics, but also the richness of its complex sedimentary structure and the importance of conducting fine and multidisciplinary excavations to answer questions about the rhythms and functions of occupations and the causalities of socio‐environmental changes