1,273 research outputs found
CĂ©nac-et-Saint-Julien â Grotte Vaufrey
Date de l'opĂ©ration : 2009 (EX) Datation par luminescence des dĂ©pĂŽts sĂ©dimentaires Lâobjectif de lâĂ©tude initiĂ©e en 2008 est dâobtenir de lâinformation chronologique sur la mise en place du remplissage sĂ©dimentaire de la Grotte Vaufrey. Dans ce but, et pour complĂ©ter les donnĂ©es radiomĂ©triques dĂ©jĂ obtenues par application de la mĂ©thode Uranium-Thorium Ă des vestiges carbonatĂ©s et par thermoluminescence sur des fragments de calcite et des silex brĂ»lĂ©s, no..
First dating results for the Middle Pleistocene industries (Acheulean â Early Middle Palaeolithic) in the Pyrenees â Garonne region: a multi methods geochronological approach (TL, OSL and TT-OSL) of the Duclos and RomentĂšres sites
The recent development work of the A65 highway has given the opportunity to broaden the corpus of Lower and Middle Palaeolithic open-air sites known in the southern Aquitaine basin. The sites of Duclos (Auriac, Pyrénées-Orientales) and RomentÚres (Le Vignau, Landes), discovered in this context, have yielded an abundant lithic record which has been attributed to the Acheulean of Iberian type for the earlier and, essentially, to the Early Middle Palaeolithic for the latter. The archaeological levels are intercalated in sequences that comprise aeolian silts and colluvial units separated by interglacial luvisols. The pedostratigraphic context of the two sites has provided a rare opportunity to propose a reliable chronostratigraphic framework in this area. To achieve this objective, a study combining several methods of luminescence dating was conducted to complete the geomorphological data. Optically Stimulated Luminescence (OSL) and Thermically Transferred OSL (TT-OSL) dating methods were applied in order to determine the ages of sedimentary quartz grains and thus, of the sampled deposits. In parallel, heated flint and quartzite samples were dated by thermoluminescence (TL). The Pyrenees-Garonne Acheulean industry of Duclos has been attributed to the boundary between Marine Isotopic Stages (MIS) 7 and 6 while the human occupations of RomentÚres date from MIS 6 for the most recent series (Early Middle Palaeolithic) and from MIS 9 and 8 for the older
Resultados do inquérito aos apicultores realizado no ùmbito do projeto MEDIBEES
No Ăąmbito do projeto MEDIBEES - Monitorização das subespĂ©cies de abelhas do MediterrĂąneo e a sua resiliĂȘncia Ă s mudanças climĂĄticas para o melhoramento sustentĂĄvel dos agroecossistemas â realizou-se um inquĂ©rito, entre outubro e novembro de 2021, com o objetivo ultimo de se caracterizar e compreender a atividade apĂcola e os seus principais problemas em Portugal, relativamente a outros paĂses da bacia MediterrĂąnea. Este inquĂ©rito foi simultaneamente implementado em Espanha, ItĂĄlia, Malta, Turquia, ArgĂ©lia, LĂbano e JordĂąnia, paĂses parceiros no consorcio MEDIBEES. O inquĂ©rito foi divulgado em Portugal atravĂ©s de correio eletrĂłnico, enviado para todas as associaçÔes de apicultores listadas no portal da FNAP, do Facebook e de contactos telefĂłnicos.peer-reviewe
Decrypting the Link Between Elliptic Primes and Twin Primes
From Caesarâs cipher to Germanyâs enigma machine to modern day cryptosytems, cryptography spans throughout history. Methods of encryption have evolved over hundreds of years and continue to evolve as computational efficiency increases. Over 2.5 quintillion bytes of data are generated per day through online networks such as banking, shopping, and social media. More than 90% of the total data in the world has been generated in the past two years, thereby requiring more sophisticated cybersecurity systems and an increasing demand for research in the field of cryptography. A curve of the form y2 = x3 + Ax + B, where A and B are constants, is what is known as an elliptic curve, which have become increasingly prevalent in modern cryptosystems. Our research focuses on the notion of elliptic primes, some of their properties, as well as some of their applications in cryptography. We also examine the primes that are both an elliptic prime and a twin prime
Le site stratifié du Bois Clair à Montguyon (Charente-Maritime, France) : récurrences paléolithiques, briÚveté des occupations et aires de débitage spécialisées
Le site du Bois Clair constitue un nouveau jalon pour la comprĂ©hension des occupations palĂ©olithiques proches de la façade atlantique. FouillĂ© dans le cadre du projet de construction de la ligne Ă grande vitesse Sud Europe Atlantique, il a livrĂ© plusieurs niveaux dâoccupations qui sâintercalent dans des dĂ©pĂŽts colluviaux et Ă©oliens au sein desquels subsistent deux horizons de sol lessivĂ© de rang interglaciaire, lâun actuel et lâautre fossile. Lâensemble de la sĂ©quence est cadrĂ© par six datations par luminescence. Si le contexte topographique et sĂ©dimentaire a favorisĂ© le panachage dâindustries sĂ©parĂ©es dans le temps, en particulier sur le point haut du site, le degrĂ© de conservation du site reste malgrĂ© tout Ă©tonnamment bon, particuliĂšrement dans la partie supĂ©rieure de la sĂ©quence oĂč lâorganisation spatiale est localement bien prĂ©servĂ©e, autorisant ainsi dâintĂ©ressantes interprĂ©tations comportementales des diffĂ©rents groupes culturels ayant frĂ©quentĂ© le site. Il se singularise par une rĂ©currence de petites occupations palĂ©olithiques sâĂ©talant de façon non linĂ©aire du MoustĂ©rien jusquâau Tardiglaciaire. Elles sont toutes matĂ©rialisĂ©es par des aires de dĂ©bitage trĂšs circonscrites dans lâespace et tournĂ©es vers des productions spĂ©cialisĂ©es. Cette Ă©tude prĂ©sente les principales donnĂ©es acquises et se focalise sur les deux niveaux les mieux conservĂ©s du site : le niveau moustĂ©rien supĂ©rieur et le niveau magdalĂ©nien. Le premier est rattachĂ© Ă un technocomplexe moustĂ©rien rĂ©cent (OIS3) Ă dĂ©bitage discoĂŻde spĂ©cifiquement tournĂ© vers une production de pointes pseudo-Levallois via des modalitĂ©s de dĂ©bitage originales, particuliĂšrement bien documentĂ©es par les remontages. Le second niveau prĂ©sentĂ© correspond Ă une brĂšve occupation de la phase finale du MagdalĂ©nien orientĂ©e vers une production de grandes lames rĂ©alisĂ©e Ă partir de cinq blocs de silex dâorigine locale.The Bois Clair site is a new benchmark for the study of the Atlantic coast area Palaeolithic settlements. Excavated during the high speed Sud Europe Atlantique train line construction project, it revealed several occupation levels, inserted in colluvial and eolian deposits displaying two argillic horizons. The sequence is chronologically established by six luminescence datings. Despite a topographic and sedimentary context leading to the mixing of chronologically distinct industries, especially at the highest point of the site, itâs state of preservation remains surprisingly good, particularly in the upper part of the sequence where the spatial organization is locally preserved, thus allowing interesting behavioral interpretations. The site stands out through recurrent and small palaeolithic settlements, dating from the Mousterian to the Late Upper Palaeolithic. These settlements all display small debitage areas, dedicated to specialized productions. This paper presents the acquired data and focuses on the two best preserved occupation levels : the Late Mousterian and Magdalenian levels. The first belongs to the late mousterian technological complex (OIS3), displaying a discoĂŻde debitage specifically dedicated to pseudo-levallois points production, achieved through original debitage methods well documented by many refittings. The second level represents a brief Late Upper Magdalenian settlement, displaying the shaping and debitage of five local flint cores, dedicated to long blade production
The saga of dyssynchrony imaging: Are we getting to the point
Cardiac resynchronisation therapy (CRT) has an established role in the management of patients with heart failure, reduced left ventricular ejection fraction (LVEFâ<â35%) and widened QRS (>130â
msec). Despite the complex pathophysiology of left ventricular (LV) dyssynchrony and the increasing evidence supporting the identification of specific electromechanical substrates that are associated with a higher probability of CRT response, the assessment of LVEF is the only imaging-derived parameter used for the selection of CRT candidates.This review aims to (1) provide an overview of the evolution of cardiac imaging for the assessment of LV dyssynchrony and its role in the selection of patients undergoing CRT; (2) highlight the main pitfalls and advantages of the application of cardiac imaging for the assessment of LV dyssynchrony; (3) provide some perspectives for clinical application and future research in this field.Conclusionthe road for a more individualized approach to resynchronization therapy delivery is open and imaging might provide important input beyond the assessment of LVEF
Recommended implementation of arterial spinâlabeled perfusion MRI for clinical applications: A consensus of the ISMRM perfusion study group and the European consortium for ASL in dementia
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109790/1/mrm25197.pd
Human Rickettsia felis Infection, Canary Islands, Spain
We report the first cases of human infection by Rickettsia felis in the Canary Islands. Antibodies against R. felis were found in 5 adsorbed serum samples from 44 patients with clinically suspected rickettsiosis by Western blot serology. Fleas from 1 patient's dog were positive for R. felis by polymerase chain reaction
Cytotoxic CD8<sup>+</sup> T lymphocytes expressing ALS-causing SOD1 mutant selectively trigger death of spinal motoneurons.
Adaptive immune response is part of the dynamic changes that accompany motoneuron loss in amyotrophic lateral sclerosis (ALS). CD4 <sup>+</sup> T cells that regulate a protective immunity during the neurodegenerative process have received the most attention. CD8 <sup>+</sup> T cells are also observed in the spinal cord of patients and ALS mice although their contribution to the disease still remains elusive. Here, we found that activated CD8 <sup>+</sup> T lymphocytes infiltrate the central nervous system (CNS) of a mouse model of ALS at the symptomatic stage. Selective ablation of CD8 <sup>+</sup> T cells in mice expressing the ALS-associated superoxide dismutase-1 (SOD1) <sup>G93A</sup> mutant decreased spinal motoneuron loss. Using motoneuron-CD8 <sup>+</sup> T cell coculture systems, we found that mutant SOD1-expressing CD8 <sup>+</sup> T lymphocytes selectively kill motoneurons. This cytotoxicity activity requires the recognition of the peptide-MHC-I complex (where MHC-I represents major histocompatibility complex class I). Measurement of interaction strength by atomic force microscopy-based single-cell force spectroscopy demonstrated a specific MHC-I-dependent interaction between motoneuron and SOD1 <sup>
G93A
</sup> CD8 <sup>+</sup> T cells. Activated mutant SOD1 CD8 <sup>+</sup> T cells produce interferon-Îł, which elicits the expression of the MHC-I complex in motoneurons and exerts their cytotoxic function through Fas and granzyme pathways. In addition, analysis of the clonal diversity of CD8 <sup>+</sup> T cells in the periphery and CNS of ALS mice identified an antigen-restricted repertoire of their T cell receptor in the CNS. Our results suggest that self-directed immune response takes place during the course of the disease, contributing to the selective elimination of a subset of motoneurons in ALS
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