Les minières de silex néolithiques des marais de Saint-Gond (Marne)

Dans la partie sud et est de la Côte d’Île-de-France, au nord des marais de Saint-Gond, des recherches documentaires intégrant de nombreuses archives inédites, des prospections pédestres et aériennes ont permis de mettre en évidence des minières de silex. Pour différentes raisons, les multiples indices d’extraction minière de cette région n’ont jamais été jugés suffisamment convaincants pour la considérer comme un secteur minier. Le regroupement d’une série d’observations objectives permet de proposer l’existence de cinq minières de silex dans cette région.Dans plusieurs sites, l’extraction du silex a été réalisée à partir de puits de plusieurs mètres de profondeur, parfois reliés par des galeries. L’absence de conservation du mobilier découvert lors de ces fouilles anciennes empêche, en attendant de nouvelles découvertes, la datation et l’attribution culturelle de ces structures d’extraction. Mais d’anciennes photographies inédites et la datation des pics en bois de cerf découverts dans la minière de Vertus « Granval » (Marne) démontrent l’exploitation du silex en minière au Néolithique récent/final. Des prospections aériennes attestent la présence de centaines de puits à silex sur certains sites, où des prospections pédestres confirment la présence de silex naturel abondant, de bonne qualité, et de grandes quantités de silex taillés.La mise en évidence d’un complexe minier dans ce secteur renouvelle entièrement les problématiques de recherche sur cette région. Celle-ci est en effet surtout connue pour ses nombreux hypogées, concentrés le long de la Côte d’Île-de-France, entre Sézanne et Épernay, et notamment dans les marais de Saint-Gond. Une telle concentration de sépultures collectives nécessite de s’interroger sur les raisons qui ont amené les populations du Néolithique récent à occuper si intensément cette région. Les minières de silex ont été creusées dans la craie campanienne, dans les mêmes secteurs que les hypogées. L’hypothèse d’une contemporanéité des deux phénomènes qui se pose maintenant ouvre de nouvelles et nombreuses perspectives de recherche à l’échelle de ce territoire.In the southern and eastern area of the Côte d’Île-de-France, north of the marshes of Saint-Gond (Marne, France), research incorporating a great deal of unpublished documentation, and the results of pedestrian and aerial surveys, has highlighted five flint mines. For various reasons, the many indications of mining activity in this region have never been considered sufficient to consider it a mining area, however, the combination of a series of objective observations suggests the existence of five flint mines.In several sites, flint mining was conducted from shafts several metres deep, sometimes connected by galleries. As many archaeological discoveries made during the earlier excavations have not been conserved, dating and cultural attribution of the structures will be only possible with new research. Nonetheless, unpublished photographs and the dating of antler picks discovered in the mine at Vertus “Granval” (Marne) demonstrate this flint mine was exploited during the Late and Final Neolithic periods. Aerial surveys attest the presence of hundreds of shafts on some sites, where walking surveys have confirmed the abundance of good quality natural flint and large quantities of flint flakes.The identification of a mining complex in this area has fully raised anew the questions relating to research in this region, best known for its numerous hypogea concentrated along the Côte d’Île-de-France, between Épernay and Sézanne, particularly in the marshes of Saint-Gond. Such a concentration of collective graves raises the question why the people of the Late Neolithic period occupied this region so intensively. The flint mines were excavated in the Campanian chalk in the same areas as the hypogea. The assumption of contemporaneity of the two phenomena opens up new perspectives of research regarding occupation of this region.Im südlichen und östlichen Teil der Côte d’Île-de-France, in den Mooren von Saint-Gond, wurden anhand dokumentarischer Nachforschungen, die zahlreiche bis dahin unbekannte Archive, Feldbegehungen und Luftprospektionen mit einbezogen, Feuersteinlagerstätten nachgewiesen. Aus verschiedenen Gründen wurden die zahlreichen Anzeichen eines Feuersteinabbaus in dieser Gegend nie als überzeugend genug angesehen, um sie als einen Sektor zu betrachten, in dem Bergbau betrieben wurde. Eine Reihe objektiver Beobachtungen erlaubt es nun, die Existenz von fünf Feuersteinlagerstätten in dieser Region vorzuschlagen.An einigen Fundplätzen wurde der Feuerstein in mehrere Meter tiefen Schächten, die durch Galerien miteinander verbunden sein konnten, abgebaut. Von diesen Altgrabungen ist kein Mobiliar erhalten. In Erwartung neuer Funde ist demzufolge weder eine Datierung noch eine kulturelle Zuordnung dieser Feuersteinabbaustrukturen möglich. Alte unveröffentlichte Fotografien und die Datierung eines Pickels aus Hirschgeweih in der Lagerstätte Vertus „Granval“ (Departement Marne) zeugen jedoch vom Feuersteinabbau im Jung- Endneolithikum. Auf Luftaufnahmen sind mancherorts hunderte von Schächten dort zuerkennen, wo bei Feldbegehungen natürlicher Feuerstein guter Qualität sowie große Mengen von bearbeitetem Feuerstein gefunden wurden.Der Nachweis von Feuersteinabbau in diesem Sektor stellt die Forschung in dieser Region vor neue Fragen. Sie ist in der Tat vor allem für ihre zahlreichen, längs der Côte d’Île-de-France, zwischen Sézanne und Épernay und insbesondere in den Mooren von Saint-Gond konzentrierten Hypogäen bekannt. Eine solche Konzentration von Kollektivbestattungen erfordert, dass man sich die Frage nach den Gründen stellt, welche die Völker des Jungneolithikums dazu bewegt haben, diese Region so intensiv zu besiedeln. Die Feuersteinminen wurden in den gleichen Sektoren in die Kreide des Campanium getrieben, wie die Hypogäen. Es drängt sich nun die Hypothese auf, dass beide Phänomene zeitgenössisch sind und eröffnet für diese Region zahlreiche neue Forschungsperspektiven

To observe or not to observe peers when learning physical examination skills; That is the question

Background: Learning physical examination skills is an essential element of medical education. Teaching strategies include practicing the skills either alone or in-group. It is unclear whether students benefit more from training these skills individually or in a group, as the latter allows them to observing their peers. The present study, conducted in a naturalistic setting, investigated the effects of peer observation on mastering psychomotor skills necessary for physical examination. Methods. The study included 185 2§ssup§nd§esup§-year medical students, participating in a regular head-to-toe physical examination learning activity. Students were assigned either to a single-student condition (n = 65), in which participants practiced alone with a patient instructor, or to a multiple-student condition (n = 120), in which participants practiced in triads under patient instructor supervision. The students subsequently carried out a complete examination that was videotaped and subsequently evaluated. Student's performance was used as a measure of learning. Results: Students in the multiple-student condition learned more than those who practiced alone (8

Detectors for the James Webb Space Telescope Near-Infrared Spectrograph I: Readout Mode, Noise Model, and Calibration Considerations

We describe how the James Webb Space Telescope (JWST) Near-Infrared Spectrograph's (NIRSpec's) detectors will be read out, and present a model of how noise scales with the number of multiple non-destructive reads sampling-up-the-ramp. We believe that this noise model, which is validated using real and simulated test data, is applicable to most astronomical near-infrared instruments. We describe some non-ideal behaviors that have been observed in engineering grade NIRSpec detectors, and demonstrate that they are unlikely to affect NIRSpec sensitivity, operations, or calibration. These include a HAWAII-2RG reset anomaly and random telegraph noise (RTN). Using real test data, we show that the reset anomaly is: (1) very nearly noiseless and (2) can be easily calibrated out. Likewise, we show that large-amplitude RTN affects only a small and fixed population of pixels. It can therefore be tracked using standard pixel operability maps.Comment: 55 pages, 10 figure

Detectors for the James Webb Space Telescope Near-Infrared Spectrograph I: Readout Mode, Noise Model, and Calibration Considerations

We describe how the James Webb Space Telescope (JWST) Near-Infrared Spectrograph's (NIRSpec's) detectors will be read out, and present a model of how noise scales with the number of multiple non-destructive reads sampling-up-the-ramp. We believe that this noise model, which is validated using real and simulated test data, is applicable to most astronomical near-infrared instruments. We describe some non-ideal behaviors that have been observed in engineering grade NIRSpec detectors, and demonstrate that they are unlikely to affect NIRSpec sensitivity, operations, or calibration. These include a HAWAII-2RG reset anomaly and random telegraph noise (RTN). Using real test data, we show that the reset anomaly is: (1) very nearly noiseless and (2) can be easily calibrated out. Likewise, we show that RTN affects only a small and fixed population of pixels. It can therefore be tracked using standard pixel operability maps

The three main monotheistic religions and gm food technology: an overview of perspectives

Abstract Background Public acceptance of genetically modified crops is partly rooted in religious views. However, the views of different religions and their potential influence on consumers' decisions have not been systematically examined and summarized in a brief overview. We review the positions of the Judaism, Islam and Christianity – the three major monotheistic religions to which more than 55% of humanity adheres to – on the controversies aroused by GM technology. Discussion The article establishes that there is no overarching consensus within the three religions. Overall, however, it appears that mainstream theology in all three religions increasingly tends towards acceptance of GM technology per se, on performing GM research, and on consumption of GM foods. These more liberal approaches, however, are predicated on there being rigorous scientific, ethical and regulatory scrutiny of research and development of such products, and that these products are properly labeled. Summary We conclude that there are several other interests competing with the influence exerted on consumers by religion. These include the media, environmental activists, scientists and the food industry, all of which function as sources of information and shapers of perception for consumers

Vitamin D deficiency contributes directly to the acute respiratory distress syndrome (ARDS)

Rationale: Vitamin D deficiency has been implicated as a pathogenic factor in sepsis and intensive therapy unit mortality but has not been assessed as a risk factor for acute respiratory distress syndrome (ARDS). Causality of these associations has never been demonstrated. Objectives: To determine if ARDS is associated with vitamin D deficiency in a clinical setting and to determine if vitamin D deficiency in experimental models of ARDS influences its severity. Methods: Human, murine and in vitro primary alveolar epithelial cell work were included in this study. Findings: Vitamin D deficiency (plasma 25(OH)D levels 600 genes. In a clinical setting, pharmacological repletion of vitamin D prior to oesophagectomy reduced the observed changes of in vivo measurements of alveolar capillary damage seen in deficient patients. Conclusions: Vitamin D deficiency is common in people who develop ARDS. This deficiency of vitamin D appears to contribute to the development of the condition, and approaches to correct vitamin D deficiency in patients at risk of ARDS should be developed

Role of Serine Racemase in Behavioral Sensitization in Mice after Repeated Administration of Methamphetamine

BACKGROUND: The N-methyl-D-aspartate (NMDA) receptors play a role in behavioral abnormalities observed after administration of the psychostimulant, methamphetamine (METH). Serine racemase (SRR) is an enzyme which synthesizes D-serine, an endogenous co-agonist of NMDA receptors. Using Srr knock-out (KO) mice, we investigated the role of SRR on METH-induced behavioral abnormalities in mice. METHODOLOGY/PRINCIPAL FINDINGS: Evaluations of behavior in acute hyperlocomotion, behavioral sensitization, and conditioned place preference (CPP) were performed. The role of SRR on the release of dopamine (DA) in the nucleus accumbens after administration of METH was examined using in vivo microdialysis technique. Additionally, phosphorylation levels of ERK1/2 proteins in the striatum, frontal cortex and hippocampus were examined using Western blot analysis. Acute hyperlocomotion after a single administration of METH (3 mg/kg) was comparable between wild-type (WT) and Srr-KO mice. However, repeated administration of METH (3 mg/kg/day, once daily for 5 days) resulted in behavioral sensitization in WT, but not Srr-KO mice. Pretreatment with D-serine (900 mg/kg, 30 min prior to each METH treatment) did not affect the development of behavioral sensitization after repeated METH administration. In the CPP paradigm, METH-induced rewarding effects were demonstrable in both WT and Srr-KO mice. In vivo microdialysis study showed that METH (1 mg/kg)-induced DA release in the nucleus accumbens of Srr-KO mice previously treated with METH was significantly lower than that of the WT mice previously treated with METH. Interestingly, a single administration of METH (3 mg/kg) significantly increased the phosphorylation status of ERK1/2 in the striatum of WT, but not Srr-KO mice. CONCLUSIONS/SIGNIFICANCE: These findings suggest first, that SRR plays a role in the development of behavioral sensitization in mice after repeated administration of METH, and second that phosphorylation of ERK1/2 by METH may contribute to the development of this sensitization as seen in WT but not Srr-KO mice

Sub-lethal concentrations of CdCl2 disrupt cell migration and cytoskeletal proteins in cultured mouse TM4 Sertoli cells

The aims of this study were to examine the effects of CdCl2 on the viability, migration and cytoskeleton of cultured mouse TM4 Sertoli cells. Time- and concentration-dependent changes were exhibited by the cells but 1 µM CdCl2 was sub-cytotoxic at all time-points. Exposure to 1 and 12 µM CdCl2 for 4 h resulted in disruption of the leading edge, as determined by chemical staining. Cell migration was inhibited by both 1 and 12 µM CdCl2 in a scratch assay monitored by live cell imaging, although exposure to the higher concentration was associated with cell death. Western blotting and immunofluorescence staining indicated that CdCl2 caused a concentration dependent reduction in actin and tubulin levels. Exposure to Cd2+ also resulted in significant changes in the levels and/or phosphorylation status of the microtubule and microfilament destabilising proteins cofilin and stathmin, suggesting disruption of cytoskeletal dynamics. Given that 1-12 µM Cd2+ is attainable in vivo, our findings are consistent with the possibility that Cd2+ induced impairment of testicular development and reproductive health may involve a combination of reduced Sertoli cell migration and impaired Sertoli cell viability depending on the timing, level and duration of exposure