29 research outputs found
PRISM (Polarized Radiation Imaging and Spectroscopy Mission): A White Paper on the Ultimate Polarimetric Spectro-Imaging of the Microwave and Far-Infrared Sky
PRISM (Polarized Radiation Imaging and Spectroscopy Mission) was proposed to
ESA in response to the Call for White Papers for the definition of the L2 and
L3 Missions in the ESA Science Programme. PRISM would have two instruments: (1)
an imager with a 3.5m mirror (cooled to 4K for high performance in the
far-infrared---that is, in the Wien part of the CMB blackbody spectrum), and
(2) an Fourier Transform Spectrometer (FTS) somewhat like the COBE FIRAS
instrument but over three orders of magnitude more sensitive. Highlights of the
new science (beyond the obvious target of B-modes from gravity waves generated
during inflation) made possible by these two instruments working in tandem
include: (1) the ultimate galaxy cluster survey gathering 10e6 clusters
extending to large redshift and measuring their peculiar velocities and
temperatures (through the kSZ effect and relativistic corrections to the
classic y-distortion spectrum, respectively) (2) a detailed investigation into
the nature of the cosmic infrared background (CIB) consisting of at present
unresolved dusty high-z galaxies, where most of the star formation in the
universe took place, (3) searching for distortions from the perfect CMB
blackbody spectrum, which will probe a large number of otherwise inaccessible
effects (e.g., energy release through decaying dark matter, the primordial
power spectrum on very small scales where measurements today are impossible due
to erasure from Silk damping and contamination from non-linear cascading of
power from larger length scales). These are but a few of the highlights of the
new science that will be made possible with PRISM.Comment: 20 pages Late
Death and the Societies of Late Antiquity
Ce volume bilingue, comprenant un ensemble de 28 contributions disponibles en français et en anglais (dans leur version longue ou abrĂ©gĂ©e), propose dâĂ©tablir un Ă©tat des lieux des rĂ©flexions, recherches et Ă©tudes conduites sur le fait funĂ©raire Ă lâĂ©poque tardo-antique au sein des provinces de lâEmpire romain et sur leurs rĂ©gions limitrophes, afin dâouvrir de nouvelles perspectives sur ses Ă©volutions possibles. Au cours des trois derniĂšres dĂ©cennies, les transformations considĂ©rables des mĂ©thodologies dĂ©ployĂ©es sur le terrain et en laboratoire ont permis un renouveau des questionnements sur les populations et les pratiques funĂ©raires de lâAntiquitĂ© tardive, pĂ©riode marquĂ©e par de multiples changements politiques, sociaux, dĂ©mographiques et culturels. Lâapparition de ce qui a Ă©tĂ© initialement dĂ©signĂ© comme une « Anthropologie de terrain », qui fut le dĂ©but de la dĂ©marche archĂ©othanatologique, puis le rĂ©cent dĂ©veloppement dâapproches collaboratives entre des domaines scientifiques divers (archĂ©othanatologie, biochimie et gĂ©ochimie, gĂ©nĂ©tique, histoire, Ă©pigraphie par exemple) ont Ă©tĂ© dĂ©cisives pour le renouvellement des problĂ©matiques dâĂ©tude : rĂ©vision dâanciens concepts comme apparition dâaxes dâanalyse inĂ©dits. Les recherches rassemblĂ©es dans cet ouvrage sont articulĂ©es autour de quatre grands thĂšmes : lâĂ©volution des pratiques funĂ©raires dans le temps, lâidentitĂ© sociale dans la mort, les ensembles funĂ©raires en transformation (organisation et topographie) et les territoires de lâempire (du cĆur aux marges). Ces Ă©tudes proposent un rĂ©examen et une rĂ©vision des donnĂ©es, tant anthropologiques quâarchĂ©ologiques ou historiques sur lâAntiquitĂ© tardive, et rĂ©vĂšlent, Ă cet Ă©gard, une mosaĂŻque de paysages politiques, sociaux et culturels singuliĂšrement riches et complexes. Elles accroissent nos connaissances sur le traitement des dĂ©funts, lâemplacement des aires funĂ©raires ou encore la structure des sĂ©pultures, en rĂ©vĂ©lant une diversitĂ© de pratiques, et permettent au final de relancer la rĂ©flexion sur la maniĂšre dont les sociĂ©tĂ©s tardo-antiques envisagent la mort et sur les Ă©lĂ©ments permettant dâidentifier et de dĂ©finir la diversitĂ© des groupes qui les composent. Elles dĂ©montrent ce faisant que nous pouvons vĂ©ritablement apprĂ©hender les structures culturelles et sociales des communautĂ©s anciennes et leurs potentielles transformations, Ă partir de lâĂ©tude des pratiques funĂ©raires.This bilingual volume proposes to draw up an assessment of the recent research conducted on funerary behavior during Late Antiquity in the provinces of the Roman Empire and on their borders, in order to open new perspectives on its possible developments. The considerable transformations of the methodologies have raised the need for a renewal of the questions on the funerary practices during Late Antiquity, a period marked by multiple political, social, demographic and cultural changes. The emergence field anthropology, which was the beginning of archaeothanatology, and then the recent development of collaborative approaches between various scientific fields (archaeothanatology, biochemistry and geochemistry, genetics, history, epigraphy, for example), have been decisive. The research collected in this book is structured around four main themes: Evolution of funerary practices over time; Social identity through death; Changing burial grounds (organisation and topography); Territories of the Empire (from the heart to the margins). These studies propose a review and a revision of the data, both anthropological and archaeological or historical on Late Antiquity, and reveal a mosaic of political, social, and cultural landscapes singularly rich and complex. In doing so, they demonstrate that we can truly understand the cultural and social structures of ancient communities and their potential transformations, based on the study of funerary practices
LâOrganisation maritime internationale et la piraterie ou le vol Ă main armĂ©e en mer : le cas de la Somalie
The age-old and recurrent scourge of piracy seems to be undergoing a transformation in the context of attacks off the coast of Somalia. The international community, confronted with major disruptions to maritime transport, is mobilizing in a quite remarkable way within the particularly tangled web of political, economic, legal and military concerns. This paper describes the overall legal framework laid down by the International Maritime Organization, a specialized United Nations agency, to combat this form of crime and the regional strategy currently being developed on the model of the Malacca Strait precedent.The age-old and recurrent scourge of piracy seems to be undergoing a transformation in the context of attacks off the coast of Somalia. The international community, confronted with major disruptions to maritime transport, is mobilizing in a quite remarkable way within the particularly tangled web of political, economic, legal and military concerns. This paper describes the overall legal framework laid down by the International Maritime Organization, a specialized United Nations agency, to combat this form of crime and the regional strategy currently being developed on the model of the Malacca Strait precedent.Martin-Castex Brice, Loonis-QuĂ©len Guillaume. LâOrganisation maritime internationale et la piraterie ou le vol Ă main armĂ©e en mer : le cas de la Somalie. In: Annuaire français de droit international, volume 54, 2008. pp. 77-117
De la fabrication Ă lâutilisation des sarcophages : le cas du site de âLa Chapelleâ Ă Jau-Dignac-et-Loirac (Gironde)
International audienc
The remarkable UV light invulnerability of thymine GNA dinucleotides
International audienceWe herein demonstrate the UV resistance of glycol nucleic acid (GNA) dinucleotides. This resistance sustains the hypothesis of GNA as a nucleic acid prebiotic ancestor on early Earth, a time of intense solar UV light. Such photorobustness, due to the absence of intrastrand base stacking, could offer an opportunity for nanodevice development requiring challenging UV conditions
SN- and NS-puckered sugar conformers are precursors of the (6â4) photoproduct in thymine dinucleotide
International audienceThe S conformation of at least one sugar residue in the TT site is crucial for (6â4) PP formation. This S sugar can be located at the 5âČ- or 3âČ-end of the TT site. The 5âČ-end S conformer location is the most efficient at providing (6â4) PP
A Minute Amount of SâPuckered Sugars Is Sufficient for (6-4) Photoproduct Formation at the Dinucleotide Level
The di-2âČ-α-fluoro analogue
of thymidylylÂ(3âČ,5âČ)Âthymidine,
synthesized to probe the effect of a minimum amount of S conformer
on the photoreactivity of dinucleotides, is endowed with only 3% and
8% of S sugar conformation at its 5âČ- and 3âČ-end, respectively.
This analogue gives rise to the (6-4) photoproduct as efficiently
as the dithymine dinucleotide (74% and 66% at the 5âČ- and 3âČ-end,
respectively) under 254 nm. Our results suggest that the 5âČ-N,
3âČ-S conformer gives rise to the (6-4) photoproduct
ColEval: Honeybee COLony Structure EVALuation for Field Surveys
Methods for the evaluation and comparison of the structure of numerous honeybee colonies are needed for the development of applied and fundamental field research, as well as to evaluate how the structure and activity of honeybee colonies evolve over time. ColEval complements existing methods, as it uses an online reference image bank for (human) learning and training purposes. ColEval is based on the evaluation of the surface area percentage occupied by different components of a honeybee colony: adult worker bees, open and capped brood, honey, nectar, and pollen. This method is an essential tool for the description of the evolution in the size of honeybee colonies. The procedure makes allowances for tendencies between different observers and uses them to calculate accurate
measurements of honeybee colony evaluation. ColEval thus allows for a posteriori comparison of under- or over-evaluation made by different observers working on the same project; it is thus possible to eliminate observer bias in the measurements and to conduct large surveys