Comunicación corta. Diferenciación de cepas vacunales del virus del síndrome reproductor y respiratorio porcino de tipo I y cepas de campo por análisis de polimorfismos en la longitud de fragmentos de restricción

The use of modified live virus (MLV) vaccines is a common procedure to control porcine reproductive and respiratory syndrome virus (PRRSV) infection in the great majority of countries from America, Asia and Europe, including Spain. Current discriminatory techniques allow the detection of different MLV type-II vaccine strains. Herein we report a rapid and accurate technique aimed to discriminate between MLV type-I vaccine strains and Spanish field strains. This technique comprises a reverse transcription (RT) and nested polymerase chain reaction (nPCR) amplification of PRRSV ORF5 followed by a digestion of RT-nPCR products with two specific endonucleases, ItaI and AccI. Combined utilization of ItaI and AccI generates restriction fragments length polymorphisms (RFLP) patterns adequate for the differentiation of 30 Spanish field isolates, of which 12 were isolated between 1991 and 1995 and 18 between 2000 and 2003. These different RFLP patterns can be used to distinguish unequivocally between Spanish field strains of PRRSV and the three MLV type-I vaccines used in Spain: AmervacPRRS®, Pyrsvac-183® and PorcilisPRRS®.Para controlar la infección por el virus del síndrome reproductor y respiratorio porcino (PRRSV), en la gran mayoría de países de América, Asia y Europa, incluyendo España, se usan frecuentemente vacunas basadas en virus vivos modificados (MLV). En la actualidad existen técnicas discriminatorias que permiten detectar cepas vacunales del PRRSV de tipo II. El presente trabajo describe una técnica precisa y rápida para la diferenciación de cepas vacunales de tipo I del PRRSV y cepas de campo españolas. Esta técnica se basa en la transcripción reversa y posterior amplificación de la ORF5 del genoma del PRRSV utilizando la reacción en cadena de la polimerasa anidada, seguida de la digestión de los amplicones generados con dos endonucleasas específicas: ItaI y AccI. La utilización combinada de ambas enzimas genera patrones de polimorfismos en la longitud de fragmentos de restricción (RFLP), adecuados para la distinción de las 30 cepas de campo usadas, de las cuales 12 fueron aisladas entre 1991 y 1995 y 18 entre 2000 y 2003. Estos diferentes patrones pueden ser utilizados para distinguir entre cepas de campo españolas del PRRSV y las tres cepas vacunales de tipo I usadas en España: AmervacPRRS®, Pyrsvac-183® y PorcilisPRRS®

The exchangeability of shape

<p>Abstract</p> <p>Background</p> <p>Landmark based geometric morphometrics (GM) allows the quantitative comparison of organismal shapes. When applied to systematics, it is able to score shape changes which often are undetectable by traditional morphological studies and even by classical morphometric approaches. It has thus become a fast and low cost candidate to identify cryptic species. Due to inherent mathematical properties, shape variables derived from one set of coordinates cannot be compared with shape variables derived from another set. Raw coordinates which produce these shape variables could be used for data exchange, however they contain measurement error. The latter may represent a significant obstacle when the objective is to distinguish very similar species.</p> <p>Results</p> <p>We show here that a single user derived dataset produces much less classification error than a multiple one. The question then becomes how to circumvent the lack of exchangeability of shape variables while preserving a single user dataset. A solution to this question could lead to the creation of a relatively fast and inexpensive systematic tool adapted for the recognition of cryptic species.</p> <p>Conclusions</p> <p>To preserve both exchangeability of shape and a single user derived dataset, our suggestion is to create a free access bank of reference images from which one can produce raw coordinates and use them for comparison with external specimens. Thus, we propose an alternative geometric descriptive system that separates 2-D data gathering and analyzes.</p

La mineralización de Li de Tres Arroyos (Alburquerque, Badajoz), como resultado de la evolución mineralógica y geoquímica del batolito de Alburquerque

La mineralización de Tres Arroyos está formada por un haz de pegmatitas litin fieras situado en el límite SW del batolito de Alburquerque. Los diques pegmatíticos aparecen en transición petrológica y geoquímica con el batolito, constituido por granitos de dos micas y diversas facies leucogranfticas marginales. Geoquímicamente, los grupos litológicos establecidos corresponden a granitos calcoalcalinos, peralumínicos, fértiles, con elevados contenidos en P y F. La evolución geoquímica observada se caracteriza por un fraccionamiento extremo, con concentración de elementos incompatibles (Li, Rb, Cs, Ga, Sn, Nb, Ta) en las fracciones magmáticas residuales y una evolución compleja en cuanto a los contenidos en Tierras Rara

A new 3D geological model and structural evolution of the world-class Rio Tinto VMS deposit, Iberian Pyrite Belt (Spain)

A new 3D geological model and structural evolution of the Rio Tinto world-class VMS deposit is presented in this work. The Rio Tinto volcanogenic massive sulfide (VMS) deposit is located in the Spanish segment of the Iberian Pyrite Belt and is hosted by felsic porphyritic volcanic rocks and tuffs. Computer generated 3D modeling of the different orebodies and host rocks has been carried out using data from around 3,000 drill-core logs, allowing us to build 93 cross-sections and 6 plants (both 50 m spacing). This has enabled us to recognize of the geometry and relationships between the mineralization and the earliest Carboniferous transtensional tectonics through the development of an extensional pull-apart basin with two sub-basins separated by the NW-SE trending Eduardo Fault. The sub-basins, Cerro Colorado and San Dionisio, were limited by two E-W strike-slip faults, the Northern and Southern faults, and bounded in the east and west by the NW-SE-trending Nerva and Western faults, respectively. The generated pull-apart basin was first filled by a basaltic magmatism of mantle origin and later, following the deposition of the intermediate complex sedimentary unit, by rhyodacitic volcanic rocks of crustal origin. The evolution of the subsiding basins caused the development of an E-W oriented rollover anticline that affected these filling rocks.As a result of a counterclockwise rotation of the stress axes, the primitive pull-apart basin evolved into a basin affected by E-W transtensional sinistral shearing. Its northern and southern limits were favorable areas for increased hydrothermal fluid flow, which gave way to the huge concentration of VMS mineralization located near the limits. The Northern and, to a lesser degree, the Southern extensional faults thus become channel areas for feeding and discharging of the VMS and stockwork ores. The main mineralizing period was related to this stage. Subsequently, during the Variscan transpressional phase, the E-W extensional faults were reactivated as inverse faults, affecting the volcanic sequence of mafic to felsic composition and the intermediate complex sedimentary unit. Fault propagation folds developed above these faults, affecting the massive sulfides, the transition series and the Culm flysch sediments, with buttressing playing a significant role in the geometry of tectonically inverted structures. The VMS mineralization and cupriferous stockworks were folded and dismembered from the original conduits in the volcanic series, and a dextral reactivation of the NW-SE trending faults also developed.Finally, it should be emphasized that this new 3D geological model is an approach to provide a better insight into the 3D structure of the world-class VMS Rio Tinto deposit and could be a key-point for further studies providing a new tool to increase knowledge of the VMS mineralizations and exploration guidelines elsewerein the IPB

Geometric and kinematics analysis of the Rio Maro fault: their implications in the genesis of karstic cavities of Cueva de Nerja type (Malaga, Spain)

A detailed geological map of 118 fault traces that form the Rio Maro Fault Zone (Malaga, Spain) has been carried out, emphasizing their geometric and kinematics characteristics. Several fault population analysis methods have been applied among them the right dihedra method, and the slip model have been utilized to establish the stress axes orientations (stress tensors) and to calculate the orientations of the maximum horizontal shortening and extension directions. Data have been analyzed to the whole population and discriminating the faults by orientations. Modelling of this fault population shows a dextral pull-apart in which specific fault orientations can influence the genesis of karstic cavities of Cueva de Nerja typ

A Comparison of Methodologies in Seismic Microzonation Mapping

Seismic Microzonation maps deals with the characterisation of the seismic risks at any of its items, hazards, vulnerability and the risk itself. In this work we are introducing focuses of two main targets, several microzonation mapping analysis and the carry out of a purely cartographical aspects methodological proposal, to be applied in any zone with a certain degree of risk in our country. Some tasks of compilation and information analysis were realised. After getting conclusions the final result was the elaboration of a seismic microzonation map model proposa