First Dinosaur Tracks from the Arabian Peninsula

Background: The evolutionary history of Mesozoic terrestrial vertebrates from the Arabian Peninsula is virtually unknown. Despite vast exposures of rocky outcrops, only a handful of fossils have yet been described from the region. Here we report a multi-taxon dinosaur track assemblage near Madar village, 47 km north of Sana’a, Republic of Yemen. This represents the first dinosaur tracksite from the Arabian Peninsula, and the only multi-taxon dinosaur ichnosite in the Middle East. Methodology/Findings: Measurements were taken directly from trackway impressions, following standard ichnological conventions. The presence of bipedal trackmakers is evidenced by a long series of pes imprints preserving smoothly rounded posterior margins, no evidence of a hallux, bluntly rounded digit tips and digital divarication angles characteristic of ornithopod dinosaurs. Nearby, eleven parallel quadrupedal trackways document a sauropod herd that included large and small individuals traveling together. Based on the morphology of manus impressions along with a narrow-gauged stance, the quadrupedal trackways were made by non-titanosauriform neosauropods. Additional isolated tracks and trackways of sauropod and ornithopod dinosaurs are preserved nearby. Conclusions/Significance: Taken together, these discoveries present the most evocative window to date into the evolutionary history of dinosaurs of the Arabian Peninsula. Given the limited Mesozoic terrestrial record from the region, this discovery is of both temporal and geographic significance, and massive exposures of similarly-aged outcrops nearby offe

Pharmacological activation of mGlu5 receptors with the positive allosteric modulator, VU0360172 modulates thalamic GABAergic transmission

Previous studies have shown that injection of the mGlu5 receptor positive allosteric modulator (PAM) VU0360172 into either the thalamus or somatosensory cortex markedly reduces the frequency of spike-and-wave discharges (SWDs) in the WAG/Rij model of absence epilepsy. Here we have investigated the effects of VU0360172 on GABA transport in the thalamus and somatosensory cortex, as possible modes of action underlying the suppression of SWDs. Systemic VU0360172 injections increase GABA uptake in thalamic synaptosomes from epileptic WAG/Rij rats. Consistent with this observation, VU0360172 could also enhance thalamic GAT-1 protein expression, depending on the dosing regimen. This increase in GAT-1 expression was also observed in the thalamus from non-epileptic rats (presymptomatic WAG/Rij and Wistar) and appeared to occur selectively in neurons. The tonic GABAA receptor current present in ventrobasal thalamocortical neurons was significantly reduced by VU0360172 consistent with changes in GAT-1 and GABA uptake. The in vivo effects of VU0360172 (reduction in tonic GABA current and increase in GAT-1 expression) could be reproduced in vitro by treating thalamic slices with VU0360172 for at least 1 hour and appeared to be dependent on the activation of PLC. Thus, the effects of VU0360172 do not require an intact thalamocortical circuit. In the somatosensory cortex, VU0360172 reduced GABA uptake but did not cause significant changes in GAT-1 protein levels. These findings reveal a novel mechanism of regulation mediated by mGlu5 receptors, which could underlie the powerful anti-absence effect of mGlu5 receptor enhancers in animal models

QDB: A new database of plasma chemistries and reactions

One of the most challenging and recurring problems when modeling plasmas is the lack of data on the key atomic and molecular reactions that drive plasma processes. Even when there are data for some reactions, complete and validated datasets of chemistries are rarely available. This hinders research on plasma processes and curbs development of industrial applications. The QDB project aims to address this problem by providing a platform for provision, exchange, and validation of chemistry datasets. A new data model developed for QDB is presented. QDB collates published data on both electron scattering and heavy-particle reactions. These data are formed into reaction sets, which are then validated against experimental data where possible. This process produces both complete chemistry sets and identifies key reactions that are currently unreported in the literature. Gaps in the datasets can be filled using established theoretical methods. Initial validated chemistry sets for SF 6 /CF 4 /O 2 and SF 6 /CF 4 /N 2 /H 2 are presented as examples

MULTIPLE REFLECTION TIME DOMAIN METHOD IN DIELECTRIC-SPECTROSCOPY - APPLICATION TO STUDY OF SOME NORMAL PRIMARY ALCOHOLS

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Réalisation d'un réflecto-interféromètre dans la bande des 70 GHz destiné à la mesure de la permittivité complexe de liquides à fortes pertes. Application a l'étude de l'eau, de l'éthylène-glycol et du formamide en fonction de la température

Description and realisation of an interferometric apparatus in the 4 mm band for the determination of the complex permittivity from reflection coefficients for high-loss liquids as a function of temperature. Application to the determination of ε' and ε" of water, ethylene-glycol and formamide at 69.2 GHz.Description et mise en oeuvre d'un banc interférométrique dans la bande des 4 mm permettant de déterminer, à partir de la mesure du coefficient de réflexion, la permittivité complexe de liquides à fortes pertes en fonction de la température. Application à la mesure de ε' et ε" de l'eau, de l'éthylène glycol et du formamide en fonction de la température à 69,2 GHz

A comparison between two indirect exponentiation methods and O.D.E. integration method for RAMS calculations based on homogeneous Markovian models

International audienceEven if solving Markovian systems is usual for dependability engineers, the choice of an adequate method to compute these systems is an actual problem for them. The object of this technical note is to contribute to the practician's information by presenting a comparison between the performances of the two most frequently used computation methods: indirect exponentiation and O.D.E. integration approaches. The retained comparison criteria and desired accuracy, computer time and computer storage required are calculated separately, although the two former are often interconnected. The O.D.E. integration method appears to be a good choice in the context of this limited study, but the optimized indirect exponentiation methods are interesting for systems with one hundred or more states—because of their good control of accuracy

An approach to assess the operational reliability of embedded equipments

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