Rapport de sondages et d'analyses, Le Kilian et les carrières anciennes de trachyte dans la Chaîne des Puys (Puy-de-Dôme)

En 2008, l'existence de carrières souterraines médiévales avait été mise en évidence dans la pente ouest du Bois de Manson qui domine la dépression du Cratère Kilian, au pied sud du puy de Dôme. En 2009-2010, des sondages et prospections ont été étendus à tout l'ensemble du Kilian de façon à préciser l'étendue et, si possible, la chronologie de son exploitation dans le passé. Ces travaux ont permis d'observer, dans le fond du cratère et sur son flanc interne ouest, des amoncellements de déblais d'un volume considérable, témoignant d'une extraction de roche à grande échelle durant le haut Moyen Âge et très probablement aussi à l'époque gallo-romaine. Une nouvelle carrière souterraine a été découverte dans la pente interne ouest du cratère. La base du remplissage de cette carrière a livré des charbons datés entre la fin du IV e siècle et le début du VI e siècle par le radiocarbone, tandis que le sommet du remplissage contenait des tessons de céramique datables, par leur typologie, de la fin du V e siècle au début du VIII e siècle. L'état actuel des investigations conduit à faire l'hypothèse que les gallo-romains ont exploité, au fond du cratère, un trachyte compact dont on ne trouve aujourd'hui que les déchets de taille, et dont les affleurements sont masqués par les déblais, tandis que les artisans du Moyen Âge ont recherché un trachyte plus tendre dans les pentes hautes du cratère. Le Kilian doit donc s'ajouter aux trois sources actuellement connues de trachyte d'oeuvre dans le passé, à savoir les volcans Sarcoui, Aumône (ou petit Suchet) et Cliersou. Dès cette découverte, en 2008, s'est posée la question de savoir quelle part éventuelle le trachyte du Kilian avait pu prendre dans la construction du temple de Mercure au sommet du puy de Dôme et dans l'agglomération gallo-romaine située au col de Ceyssat. Pour y répondre, une campagne d'analyses géochimiques et pétrographiques été engagée pour caractériser, aux fins de comparaison, non seulement les trachytes du Kilian et ceux des ruines gallo-romaines, mais, de plus, les trachytes du Cliersou, de l'Aumône et du Sarcoui. Ces analyses ont finalement montré qu'il est possible de faire une discrimination statistiquement significative entre les différents trachytes étudiés, à l'exception de ceux du couple Cliersou-Aumône dont les laves sont très peu différentes les unes des autres. Le résultat le plus remarquable est que tous les trachytes gallo-romains échantillonnés (dont 10 échantillons distincts au temple de Mercure et 10 au col de Ceyssat) se rattachent sans ambiguïté au Kilian. En toute rigueur, ces nouvelles données ne permettent pas d'exclure sans appel la possibilité d'utilisation à l'époque gallo-romaine, au temple de Mercure et au col de Ceyssat, de trachytes provenant d'autres sources que le Kilian (cas des chaperons de mur du col de Ceyssat, provenant du puy de Dôme). Cependant, il faut ajouter qu'un examen visuel des trachytes d'oeuvre dans ces deux sites, portant sur un nombre de moellons et d'éléments architecturaux bien supérieur au nombre de ceux qui ont été analysés, conduit à conclure que leur source est probablement commune. Cette conclusion est basée sur un faciès minéralogique particulier, observable à l'oeil nu ou à la loupe

SMAC Mimetic BV6 Induces Cell Death in Monocytes and Maturation of Monocyte-Derived Dendritic Cells

Background: Compounds mimicking the inhibitory effect of SMAC / DIABLO on X-linked inhibitor of apoptosis (XIAP) have been developed with the aim to achieve sensitization for apoptosis of tumor cells resistant due to deregulated XIAP expression. It turned out that SMAC mimetics also have complex effects on the NFkB system and TNF signaling. In view of the overwhelming importance of the NFkB transcription factors in the immune system, we analyzed here the effects of the SMAC mimetic BV6 on immune cells. Principal Findings: BV6 induced apoptotic and necrotic cell death in monocytes while T-cells, dendritic cells and macrophages were largely protected against BV6-induced cell death. In immature dendritic cells BV6 treatment resulted in moderate activation of the classical NFkB pathway, but it also diminished the stronger NFkB-inducing effect of TNF and CD40L. Despite its inhibitory effect on TNF- and CD40L signaling, BV6 was able to trigger maturation of immature DCs as indicated by upregulation of CD83, CD86 and IL12. Significance: The demonstrated effects of SMAC mimetics on immune cells may complicate the development of tumor therapeutic concepts based on these compounds but also arise the possibility to exploit them for the development of immune stimulatory therapies

Listeners feel the beat: Entrainment to English and French speech rhythms

Can listeners entrain to speech rhythms? Monolingual speakers of English and French and balanced English–French bilinguals tapped along with the beat they perceived in sentences spoken in a stress-timed language, English, and a syllable-timed language, French. All groups of participants tapped more regularly to English than to French utterances. Tapping performance was also influenced by the participants’ native language: English-speaking participants and bilinguals tapped more regularly and at higher metrical levels than did French-speaking participants, suggesting that long-term linguistic experience with a stress-timed language can differentiate speakers’ entrainment to speech rhythm

Unconsciously Triggered Conflict Adaptation

In conflict tasks such as the Stroop, the Eriksen flanker or the Simon task, it is generally observed that the detection of conflict in the current trial reduces the impact of conflicting information in the subsequent trial; a phenomenon termed conflict adaptation. This higher-order cognitive control function has been assumed to be restricted to cases where conflict is experienced consciously. In the present experiment we manipulated the awareness of conflict-inducing stimuli in a metacontrast masking paradigm to directly test this assumption. Conflicting response tendencies were elicited either consciously (through primes that were weakly masked) or unconsciously (strongly masked primes). We demonstrate trial-by-trial conflict adaptation effects after conscious as well as unconscious conflict, which could not be explained by direct stimulus/response repetitions. These findings show that unconscious information can have a longer-lasting influence on our behavior than previously thought and further stretch the functional boundaries of unconscious cognition

How Awareness Changes the Relative Weights of Evidence During Human Decision-Making

A combined behavioral and brain imaging study shows how sensory awareness and stimulus visibility can influence the dynamics of decision-making in humans

Subliminal Semantic Priming in Speech

Numerous studies have reported subliminal repetition and semantic priming in the visual modality. We transferred this paradigm to the auditory modality. Prime awareness was manipulated by a reduction of sound intensity level. Uncategorized prime words (according to a post-test) were followed by semantically related, unrelated, or repeated target words (presented without intensity reduction) and participants performed a lexical decision task (LDT). Participants with slower reaction times in the LDT showed semantic priming (faster reaction times for semantically related compared to unrelated targets) and negative repetition priming (slower reaction times for repeated compared to semantically related targets). This is the first report of semantic priming in the auditory modality without conscious categorization of the prime

Subliminal Semantic Priming in Speech

Numerous studies have reported subliminal repetition and semantic priming in the visual modality. We transferred this paradigm to the auditory modality. Prime awareness was manipulated by a reduction of sound intensity level. Uncategorized prime words (according to a post-test) were followed by semantically related, unrelated, or repeated target words (presented without intensity reduction) and participants performed a lexical decision task (LDT). Participants with slower reaction times in the LDT showed semantic priming (faster reaction times for semantically related compared to unrelated targets) and negative repetition priming (slower reaction times for repeated compared to semantically related targets). This is the first report of semantic priming in the auditory modality without conscious categorization of the prime

Evaluating automatic speech recognition systems as quantitative models of cross-lingual phonetic category perception

International audienceTheories of cross-linguistic phonetic category perception posit that listeners perceive foreign sounds by mapping them onto their native phonetic categories, but, until now, no way to effectively implement this mapping has been proposed. In this paper, Automatic Speech Recognition systems trained on continuous speech corpora are used to provide a fully specified mapping between foreign sounds and native categories. The authors show how the machine ABX evaluation method can be used to compare predictions from the resulting quantitative models with empirically attested effects in human cross-linguistic phonetic category perception

Vowel reduction in word-final position by early and late Spanish-English bilinguals

Vowel reduction is a prominent feature of American English, as well as other stress-timed languages. As a phonological process, vowel reduction neutralizes multiple vowel quality contrasts in unstressed syllables. For bilinguals whose native language is not characterized by large spectral and durational differences between tonic and atonic vowels, systematically reducing unstressed vowels to the central vowel space can be problematic. Failure to maintain this pattern of stressed-unstressed syllables in American English is one key element that contributes to a ?foreign accent? in second language speakers. Reduced vowels, or ?schwas,? have also been identified as particularly vulnerable to the co-articulatory effects of adjacent consonants. The current study examined the effects of adjacent sounds on the spectral and temporal qualities of schwa in word-final position. Three groups of English-speaking adults were tested: Miami-based monolingual English speakers, early Spanish-English bilinguals, and late Spanish-English bilinguals. Subjects performed a reading task to examine their schwa productions in fluent speech when schwas were preceded by consonants from various points of articulation. Results indicated that monolingual English and late Spanish-English bilingual groups produced targeted vowel qualities for schwa, whereas early Spanish-English bilinguals lacked homogeneity in their vowel productions. This extends prior claims that schwa is targetless for F2 position for native speakers to highly-proficient bilingual speakers. Though spectral qualities lacked homogeneity for early Spanish-English bilinguals, early bilinguals produced schwas with near native-like vowel duration. In contrast, late bilinguals produced schwas with significantly longer durations than English monolinguals or early Spanish-English bilinguals. Our results suggest that the temporal properties of a language are better integrated into second language phonologies than spectral qualities. Finally, we examined the role of nonstructural variables (e.g. linguistic history measures) in predicting native-like vowel duration. These factors included: Age of L2 learning, amount of L1 use, and self-reported bilingual dominance. Our results suggested that different sociolinguistic factors predicted native-like reduced vowel duration than predicted native-like vowel qualities across multiple phonetic environments