Estudio del Terciario marino de la sierra del Mugrón (Prov. Albacete y Valencia)

The Miocene sediments of sierra del Mugron give us a good example of marine sedimentation in littoral facies. The stratigraphic observatior~s effectued, the petrologic characteristics of these materials and their classification, are analyzed in this paper. The set of these dates, with the help of macro and micropaleontologic criteries permits to interpret the conditions of deposition. It is concluded this deposition occurred in the internal continental plattform, in relation with regional tectonic process and a great development of coloriial organisms

Paleoseismological analysis of late Miocene lacustrine successions in the Prebetic Zone, SE Spain

A paleoseismological study of late Miocene lacustrine sediments was carried out in the Neogene basins of the Prebetic Zone in Albacete (Spain). We developed a multidisciplinary methodology which could be used to extrapolate the paleoseismic data to the present day. This multidisciplinary approach includes different disciplines, i.e. stratigraphy, structural analysis, seismological analysis and paleoseismology. Paleoseismological analysis was focussed on both shallow and deep lake deposits given that these sediments behave differently in different deformation fields. The seismites formed in shallow sediments were generated by liquefaction and include: sand dikes, pillow structures and intruded and fractured gr avels. The deep lake deposits show varied structures, such as loop bedding, disturbed varved lamination, mixed layers and pseudonodules. Seismites indicate paleoearthquake magnitude intervals. The trends of the seismites are usually oriented ve ry close to the stress field trends (from the late Miocene to the Present): NW-SE and NE-SW trends. This constitutes a link between tectonics and seismites. The va rved annual sedimentation evidenced by the deep lake facies was used as a relative dating method. Mixed layers were employed as paleoseismic indicators to calculate the earthquake recurrence interval. The mean recurrence interval is close to 130 years (9446 years of total record with 73 dated events), one maximum interval of 454 years and one minimum interval of 23 years and the mean estimated magnitude value is 5.1. The Gutenberg-Richter relationship shows similar "b" values close to 0.86 from paleoseismological and seismological data. This suggests that the seismic conditions have been similar since the late Miocene

Astronomical forcing of sedimentary cycles in the middle to late Miocene continental Calatayud Basin (NE Spain)

A high-resolution cyclostratigraphic and magnetostratigraphic study was carried out on cyclically bedded successions of middle Miocene lacustrine to distal alluvial fan-floodplain deposits from the Calatayud basin, in northeast Spain. Eight (partially overlapping) subsections near the village of Orera are correlated in detail using distinct sedimentary cycle patterns or by following marker beds in the field. Together they form the Orera Composite Section (OCS). Sedimentary cycles are recognised on at least two different scales. The basic small-scale cycles in the OCS consist of an alternation of grey and, occasionally, red clays with white, dolomite-rich, carbonate beds. They are arranged in largerscaled, so-called large-scale cycles based on repetitive changes in the overall carbonate-clay lithology. Two other, but less distinct, types of intermediate scale cyclicity are also recognised. In terms of depositional environment, the cycle hierarchy is interpreted to represent periodic lake expansion over the palaeo-alluvial fan-floodplain area. The palaeomagnetic results yield a reliable magnetostratigraphic record, which confirms the cyclostratigraphic correlations between the subsections in detail. Rock magnetic experiments reveal that haematite is the main magnetic carrier of the primary component. The magnetostratigraphy of the OCS is correlated straightforwardly with the geomagnetic polarity time scale. This resulted in an age of 10.7-12.8 Ma for the entire succession, which is supported by fossil micromammal findings. In addition, it also reveals the presence of two, possibly three, short new polarity intervals. Based on the number of cycles in the OCS the average periodicity of the basic small-scale cycles is approximately 23 000 yr, while the large-scale cycle indicates a periodicity of 400 000 yr. This suggests that these sedimentary cycles are controlled by astronomically induced climate changes causing lake-level fluctuations and thus resulting in the deposition of carbonate-clay cycles. The continental sequences of the OCS provide a unique opportunity to extend the astronomical polarity time scale into the middle Miocene. The overlap of such continental sequences in the Mediterranean area with time-equivalent astronomically induced marine sequences is fundamental for establishing marine^continental, bed-tobed, correlations and for understanding regional climate change

Continuous cell lines and immune ascitic fluid pools in arbovirus detection

Pour la recherche et l'isolement des arbovirus, des expérimentations successives nous ont amenés à utiliser, parmi les lignées de cellules en culture continue dont l'utilisation est préconisée par l'OMS, les deux systèmes cellulaires MOS61 (cellules de #Aedes pseudoscutellaris$) et Vero. La détection des virus dans les sytèmes cellulaires est réalisée à l'aide de 7 pools de 10 ascites hyperimmunes polyvalentes. Cette technique permet la mise en évidence de 70 sur 80 arbovirus transmis par les moustiques en Afrique, et permet de détecter très facilement les associations d'arbovirus grâce aux ascites immunes monospécifiques ou monoclonales (dengue-1-2-3-4 et fièvre jaune). (Résumé d'auteur

Ecology of tick as potentiel vectors of Crimean-Congo hemorrhagic fever virus in Senegal : epidemiological implications

Au moins trente espèces de tiques, provenant de 7 genres, ont été trouvées infectées du virus de la fièvre hémorragique de Crimée Congo. A cette liste, nous ajoutons #Rhipicephalus guilhoni. En Afrique subsaharienne, 17 espèces de tiques ont été reconnues en tant que vecteur de la maladie, dont 12 sont présents en Sénégambie et Mauritanie. Ont été étudiées les cinq plus importantes espèces dans la transmission du virus CCHF au Sénégal : #Amblyomma variegatum, #Hyalomma impeltatum, #Hyalomma marginatum rufipes, #Hyalomma truncatum$, et #Rhipicephalus guilhoni

The Approach to Ergodicity in Monte Carlo Simulations

The approach to the ergodic limit in Monte Carlo simulations is studied using both analytic and numerical methods. With the help of a stochastic model, a metric is defined that enables the examination of a simulation in both the ergodic and non-ergodic regimes. In the non-ergodic regime, the model implies how the simulation is expected to approach ergodic behavior analytically, and the analytically inferred decay law of the metric allows the monitoring of the onset of ergodic behavior. The metric is related to previously defined measures developed for molecular dynamics simulations, and the metric enables the comparison of the relative efficiencies of different Monte Carlo schemes. Applications to Lennard-Jones 13-particle clusters are shown to match the model for Metropolis, J-walking and parallel tempering based approaches. The relative efficiencies of these three Monte Carlo approaches are compared, and the decay law is shown to be useful in determining needed high temperature parameters in parallel tempering and J-walking studies of atomic clusters.Comment: 17 Pages, 7 Figure