Mantos inducidos por microbialitas en sedimentos siliciclásticos plio-cuaternarios? del NO de Iberia

Microbial mats are organo-sedimentary deposits formed by bacteria that trap or synthesize certain chemical elements. This type of activity gives rise to the formation of lamellar and/or columnar bioconstructions (stromatolites) and/or concentric structures (oncolites and thrombolites). The study of microbial mats used to be restricted mainly to marine and coastal environments related to the formation of ancient carbonate sediments (Palaeozoic/Proterozoic), and/or extreme conditions in hypersaline environments. However, in recent years, the presence of these forms has been identified in continental siliciclastic rocks and sediments with a temporal distribution that reaches into modern times. In this study, several levels of ferruginous crusts associated with microbial activity are found, interspersed in a Cenozoic deposit located in the province of Zamora. This deposit consists of concentric, laminated iron structures filled with silt, interspersed throughout a clayey-silt layer of variegated colors which shows signs of bioturbation and desiccation due to fluid escape. These findings allow the inference of the sedimentary and climatic conditions responsible for the growth and preservation of microbial mats in the siliciclastic sediments of the north-western edge of the Duero BasinLos mantos microbiales constituyen depósitos organosedimentarios formados por bacterias que atrapan o sintetizan determinados elementos químicos. Este tipo de actividad da lugar a la formación de estructuras laminares y/o columnares (estromatolitos) y/o concéntricas (oncolitos y trombolitos). Su estudio, por tanto, quedaba reducido principalmente a ambientes marinos y litorales relacionados con la formación de sedimentos carbonatados de edad muy antigua (Paleozoico/ Proterozoico), y/o condiciones extremas en ambientes hipersalinos. Sin embargo, en los últimos años, se ha identificado la presencia de estas formas en rocas y sedimentos de afinidad continental y carácter siliciclástico, que se extienden temporalmente hasta la actualidad. En este estudio, se presenta el hallazgo de varios niveles de costras ferruginosas asociadas a la actividad microbiana, intercalados en un depósito cenozoico de la provincia de Zamora. Se trata de una serie de niveles caracterizados por la presencia de capas ferruginosas laminadas y concéntricas, constituidas por limos que aparecen en el techo y muro de un nivel arcilloso-limoso de colores abigarrados y signos de bioturbación y desecación por escape de fluidos. Este singular hallazgo permite establecer las condiciones sedimentarias y climáticas responsables del crecimiento y conservación de mantos microbianos en sedimentos siliciclásticos del borde noroccidental de la cuenca del Duer

Low-lying spectra in anharmonic three-body oscillators with a strong short-range repulsion

Three-body Schroedinger equation is studied in one dimension. Its two-body interactions are assumed composed of the long-range attraction (dominated by the L-th-power potential) in superposition with a short-range repulsion (dominated by the (-K)-th-power core) plus further subdominant power-law components if necessary. This unsolvable and non-separable generalization of Calogero model (which is a separable and solvable exception at L = K = 2) is presented in polar Jacobi coordinates. We derive a set of trigonometric identities for the potentials which generalizes the well known K=2 identity of Calogero to all integers. This enables us to write down the related partial differential Schroedinger equation in an amazingly compact form. As a consequence, we are able to show that all these models become separable and solvable in the limit of strong repulsion.Comment: 18 pages plus 6 pages of appendices with new auxiliary identitie

Levantamientos topográficos en la III Campaña de Excavaciones en Tell Mahuz - Iraq I

In the third campaign of the archaeological excavations performed in Tell Mahuz (September-October 2000), a group of Surveying engineers has taken part, whose aim has been the mapping of Tell and its environment. The surface to be represented exceeds 100 hectares. This article highlights the peculiarities to take into account when mapping an archaeological site, and it describes the fieldwork carried out during the campain

Transient Propagation and Scattering of Quasi-Rayleigh Waves in Plates: Quantitative comparison between Pulsed TV-Holography Measurements and FC(Gram) elastodynamic simulations

We study the scattering of transient, high-frequency, narrow-band quasi-Rayleigh elastic waves by through-thickness holes in aluminum plates, in the framework of ultrasonic nondestructive testing (NDT) based on full-field optical detection. Sequences of the instantaneous two-dimensional (2-D) out-of-plane displacement scattering maps are measured with a self-developed PTVH system. The corresponding simulated sequences are obtained by means of an FC(Gram) elastodynamic solver introduced recently, which implements a full three-dimensional (3D) vector formulation of the direct linear-elasticity scattering problem. A detailed quantitative comparison between these experimental and numerical sequences, which is presented here for the first time, shows very good agreement both in the amplitude and the phase of the acoustic field in the forward, lateral and backscattering areas. It is thus suggested that the combination of the PTVH system and the FC(Gram) elastodynamic solver provides an effective ultrasonic inspection tool for plate-like structures, with a significant potential for ultrasonic NDT applications.Comment: 46 pages, 16 figures, corresponding author Jos\'e Carlos L\'opez-V\'azquez, [email protected]. Changes: 1st, 4th, 5th paragraphs (intro), 3rd, 4th paragraphs (sec. 4); [59-60] cited only in appendixes; old ref. [52] removed; misprints corrected in the uncertainty of c_L (subsec. 3.1), citation to fig. 10 (sec. 4), size of images (caption fig.15); reference to Lam\'e constants removed in subsec. 3.

An educational tool for understanding MPEG‐2 video compression and coding techniques

The understanding of the video encoding/decoding processes is a key skill for students of computer science, engineering, or telecommunications, especially those specialized in multimedia. The special characteristics of the video signals, and how such features are leveraged to compress the video frames using coding theory, are hard to understand for engineering students. In this paper, we describe MPEG-2 analyzer, an educational tool designed to provide a comprehensive and interactive way to understand MPEG-2 video compression and encoding techniques. We have used our tool to evaluate its usefulness in reinforcing the knowledge about the MPEG-2 video (de)coding process to Telecommunication Engineering students. Results show that the evaluation of the tool is very positive, and it has helped them to understand many of the complex concepts covered in the course.Funding for open access charge: Universidad de Málaga / CBUA

Problemas de salud y factores determinantes del número de visitas a demanda en pacientes hiperutilizadores de un centro de salud

ObjetivosDescribir las características sociodemográficas y problemas de salud que presentan los pacientes hiperconsultadores de un centro de salud y determinar los factores que explican el número de visitas solicitadas en consulta demanda del médico de familia.DiseñoDescriptivo, retrospectivo. Análisis multivariante: regresión lineal múltiple.EmplazamientoCentro de salud urbano.PacientesPacientes que han solicitado cita para consulta demanda en el centro de salud en al menos nueve ocasiones durante 1999 (n = 7.852). Muestra aleatoria de 386 pacientes (alfa, 0,05; precisión, 95%).Mediciones y resultados principalesVariable dependiente: número de consultas demanda solicitadas en 1999. Variables independientes: edad, tamaño familiar, zona residencia, activo o pensionista, inclusión en programas, problemas de salud (CIAP-2), número de fármacos en prescripción repetida (clasificación anatómica), incapacidad laboral temporal (IT). Los hiperconsultadores son un 57,8% (IC, 52,9-62,7%) mujeres; edad media, 55 años (DE, 18,5); tamaño familiar, 2,7 miembros (DE, 1,457); 58,8% pensionistas; número medio de citas, 15 (DE, 6,7); consumo medio, 1,58 (DE, 2,46) fármacos de forma habitual; inclusión en programas: 37,7%, hipertensión; 16%, diabetes; 17%, dislipemia; 16%, consulta de enfermería. Patologías más prevalentes: cardiocirculatorias (43,8%), endocrinometabólicas (32%), traumatológicas (26,7%) y salud mental (21%). El modelo de regresión incluye las variables edad, número de fármacos y haber estado en IT.ConclusionesLos hiperconsultadores de nuestro centro de salud son mujeres de edad media con problemas de salud física de evolución crónica y problemas de salud mental. El número de visitas está relacionado con la edad y las necesidades administrativas: medicación y bajas.ObjectivesTo describe the social and demographic characteristics and health problems of over-users of a health centre and to determine the number of attendances requested on demand at the general medical clinic.DesignRetrospective and descriptive. Multivariate analysis: multiple linear regression.SettingUrban health centre.PatientsPatients who requested a consultation at the health centre on at least nine occasions in 1999 (N = 7852). Random sample of 386 patients (alpha 0.05, 95% accuracy).Measurements and main resultsDependent variable: number of on-demand consultations requested in 1999. Independent variables: age, family size, area of residence, active or pensioner, inclusion in programmes, health problems (CIAP-2), number of drugs on repeat prescription (Anatomical Classification), short-term time off work. 57% of over-users were women (CI, 52.9-62.7%); mean age 55 (SD 18.5); family size 2.7 members (SD 1.457); 58.8% pensioners. Mean number of appointments 15 (SD 6.7). Mean habitual consumption of 1.58 medicines (SD 2.46). Inclusion in programmes: 37.7% hypertension, 16% diabetes, 17% dyslipaemia, 16% nursing clinic. Most prevalent pathologies: cardiocirculatory (43.8%), endocrino-metabolic (32%), traumatology (26.7%) and mental health (21%). The regression model included the variables of age, number of medicines and having had short-term time off.ConclusionsOver-users of our health centre are middle-aged women with chronic physical health problems and with mental health problems. The number of attendances is related to age and administrative requirements: medication and sick notes