Cooperative Virus-Virus Interactions: An Evolutionary Perspective

Despite extensive evidence of virus-virus interactions, not much is known about their biological significance. Importantly, virus-virus interactions could have evolved as a form of cooperation or simply be a by-product of other processes. Here, we review anddiscuss different types of virus-virus interactions from the point of view of social evolution, which provides a well-establishedframework for interpreting thefitness costs and benefits of such traits. We also classify interactions according to theirmechanisms of action and speculate on their evolutionary implications. As in any other biological system, the evolutionarystability of viral cooperation critically requires cheaters to be excluded from cooperative interactions. We discuss how cheaterviruses exploit cooperative traits and how viral populations are able to counteract this maladaptive process

Evolución social de virus

Durante muchos años se ha asumido que los virus se transmiten como elementos individuales, en forma de partículas (viriones) que contienen un único genoma. En los últimos años, se ha incrementado sustancialmente la evidencia de que muchos virus son capaces de transmitirse en grupos de viriones, lo que les permite iniciar infecciones con más de un individuo, ya sea en un nuevo hospedador, o en una nueva célula, dentro de un organismo pluricelular. Concretamente, se han descrito multitud de estructuras, promovidas por genes virales, a las que se conoce como unidades de infección colectivas, que permiten el agrupamiento, transporte, y llegada conjunta de múltiples genomas o partículas virales. Independientemente de las características específicas de cada una de estas estructuras, lo común en todas ellas es que incrementan el número de genomas virales que inician una nueva infección. La transmisión colectiva abre la puerta a los virus a múltiples interacciones, las cuales pueden ser estudiadas desde el punto de vista de la evolución social, al igual que ocurre con otros microorganismos. En esta tesis estudiamos tres ejemplos de interacciones virales que, como demostramos, se pueden entender desde la óptica de la evolución social.For many years it has been assumed that viruses are transmitted as single elements, in the form of particles (virions) containing a single genome. In recent years, there has been substantially increasing evidence that many viruses are capable of transmitting in clusters of virions, allowing them to initiate infections with more than one individual, either in a new host, or in a new cell, within a multicellular organism. Specifically, a multitude of structures have been described, promoted by viral genes, known as collective infection units, which allow the clustering, transport, and joint arrival of multiple genomes or viral particles. Regardless of the specific characteristics of each of these structures, what is common to all of them is that they increase the number of viral genomes that initiate a new infection. Collective transmission opens the door for viruses to multiple interactions, which can be studied from the point of view of social evolution, as occurs with other microorganisms. In this thesis we study three examples of viral interactions that, as we demonstrate, can be understood from the point of view of social evolution

Tsunami hazard assessment in the southern Colombian Pacific basin and a proposal to regenerate a previous barrier island as protection

ABSTRACT: In this study, the tsunami hazard posed to 120 000 inhabitants of Tumaco (Colombia) is assessed, and an evaluation and analysis of regenerating the previous El Guano Island for tsunami protection is conducted. El Guano Island was a sandy barrier island in front of the city of Tumaco until its disappearance during the tsunami of 1979; the island is believed to have played a protective role, substantially reducing the scale of the disaster. The analysis is conducted by identifying seismotectonic parameters and focal mechanisms of tsunami generation in the area, determining seven potential generation sources, applying a numerical model for tsunami generation and propagation, and evaluating the effect of tsunamis on Tumaco. The results show that in the current situation, this area is vulnerable to impact and flooding by tsunamis originating nearby. El Guano Island was found to markedly reduce flood levels and the energy flux of tsunami waves in Tumaco during the 1979 tsunami. By reducing the risk of flooding due to tsunamis, the regeneration and morphological modification of El Guano Island would help to protect Tumaco

Comparison of Four Polymerase Chain Reaction Methods for the Rapid Detection of Human Fecal Pollution in Marine and Inland Waters

We compared the effectiveness of three PCR protocols for the detection of Bifidobacterium adolescentis and one PCR protocol for detecting Bacteroidales as indicators of human fecal pollution in environmental samples. Quantitative PCR indicated that a higher concentration of B. adolescentis DNA was recovered from sewage samples on the 0.2 μm filters compared to the 0.45 μm filters, and there was no evidence of qPCR inhibitors in the DNA extracts. With the Matsuki method (1999), B. adolescentis was detected only in undiluted sewage samples. The King method (2007) performed well and detected B. adolescentis in all of the sewage dilutions (from undiluted to 10−4). In contrast, the Bonjoch approach (2004) was effective at detecting B. adolescentis at lower dilutions (10−3) of sewage samples and it gave false positive results with some (3/8) pig fecal samples. Human-specific Bacteroidales (HuBacs) were detected in the lower diluents of sewage samples but was positive in pig (6/8) and cattle fecal samples. PCR detection of B. adolescentis in marine samples from Puerto Rico and freshwater samples from Georgia indicated that the PCR method of King et al. (2007) and the modified Layton method for HuBac were in agreement in detecting human fecal pollution in most sites

Migration and validation of non-formal and informal learning in Europe:inclusion, exclusion or polarization in the recognition of skills?

This article explores (1) the degree to which immigrants can be considered dominant groups in the area of validation of non-formal and informal learning and are subject to specific validation measures in 33 European countries; (2) whether country clusters can be identified within Europe with regard to the dominance of immigrants in the area of validation; and (3) whether validation systems are likely to lead to the inclusion of immigrants or foster a process of “devaluation” of their skills and competences in their host countries. Based on the European Inventory on validation of non-formal and informal learning project (chiefly its 2014 update) as well as a review of 124 EU-funded (Lifelong Learning Programme and European Social Fund) validation projects, the authors present the following findings: (1) in the majority of European countries, immigrants are not a dominant group in the area of validation. (2) In terms of country clusters, Central European and Nordic countries tend to consider immigrants a dominant target group for validation to a greater extent than Southern and Eastern European countries. (3) Finally, few initiatives aim to ensure that immigrants’ skills and competences are not devalued in their host country, and those initiatives which are in place benefit particularly those defined as “highly skilled” individuals, on the basis of their productive potential. There is, thus, a “low road” and a “high road” to validation, leading to a process of polarisation in the recognition of the skills and competences of immigrant

Herramienta basada en el navegador Web para el reporte de errores en el contexto de sistemas Web

Esta tesina se enfoca en mejorar el proceso de reporte de errores en sistemas web, el cual cumple un rol central en el proceso de desarrollo de software. Los usuarios encargados de realizar estos reportes suelen ser ajenos al ámbito de la informática y desconocen qué información es útil para la identificación de los errores, lo que deriva en un retraso en la resolución del mismo. Es importante que la información brindada por el usuario ayude con la rápida y correcta resolución de los errores. Para ello desarrollamos una extensión de navegador que recopila información del contexto de la navegación del usuario que será procesada y anexada al reporte que el usuario realiza normalmente. Esta herramienta fue probada por desarrolladores a los cuales se los hizo identificar errores reportados con y sin la herramienta desarrollada para probar la eficacia en cuanto al tiempo requerido para la identificación de los errores.Facultad de Informátic

Tsunami hazard at the Western Mediterranean Spanish coast from

Abstract. Spain represents an important part of the tourism sector in theWestern Mediterranean, which has been affected in the past by tsunamis. Although the tsunami risk at the Spanish coasts is not the highest of the Mediterranean, the necessity of tsunami risk mitigation measures should not be neglected. In the Mediterranean area, Spain is exposed to two different tectonic environments with contrasting characteristics. On one hand, the Alboran Basin characterised by transcurrent and transpressive tectonics and, on the other hand, the North Algerian fold and thrust belt, characterised by compressive tectonics. A set of 22 seismic tsunamigenic sources has been used to estimate the tsunami threat over the Spanish Mediterranean coast of the Iberian peninsula and the Balearic Islands. Maximum wave elevation maps and tsunami travel times have been computed by means of numerical modelling and we have obtained estimations of threat levels for each source over the Spanish coast. The sources on the Western edge of North Algeria are the most dangerous, due to their threat to the South-Eastern coast of the Iberian Peninsula and to theWestern Balearic Islands. In general, the Northern Algerian sources pose a greater risk to the Spanish coast than the Alboran Sea sources, which only threaten the peninsular coast. In the Iberian Peninsula, the Spanish provinces of Almeria and Murcia are the most exposed, while all the Balearic Islands can be affected by the North Algerian sources with probable severe damage, specially the islands of Ibiza and Minorca. The results obtained in this work are useful to plan future regional and local warning systems, as well as to set the priority areas to conduct research on detailed tsunami risk

Tsunami Resonance in Palma Bay and Harbor, Majorca Island, as induced by the 2003 Western Mediterranean Earthquake

ABSTRACT: he tsunami induced by the May 21, 2003, Algerian Boumerde`s-Zemmouri earthquake (moment magnitude Mw=6.9) propagated across the western Mediterranean Basin, thereby causing material damages in some harbors and coastal areas. This was the case in the Balearic Islands and particularly the Palma harbor. Attempts to simulate the 2003 tsunami event found discrepancies between tsunami arrival times and wave amplitude when comparing tide gauge records with results from numerical models. To date, all published model results of the amplitude of the tsunami are underestimations, attributed to numerical limitations due to the lack of high-resolution bathymetry and poor definition of harbor geometry. Other views suggest the nappropriateness of the available seismic source parameterizations and the possible occurrence of submarine landsliding triggered by the earthquake that has not been included in the numerical simulations. In this article we present the results of a numerical study aimed at better understanding the response of the interacting Palma bay and harbor under the impact of the 2003 western Mediterranean tsunami. The transference of the tsunami energy from the generation area to the continental shelf, the bay, and the harbor has been studied and compared with the natural oscillation modes of the bay and harbor water bodies. Our work includes a sensitivity analysis of the source parameterization and the bathymetry grid size for the bay and harbor as a way to explain the discrepancies between simulations and observations. The Palma harbor tide gauge shows that energy from the tsunami concentrated mainly in periods that fitted to the natural modes of oscillations of the bay. Therefore, the significant wave amplification observed inside the harbor, mainly in its northern basin, was generated by a resonance effect induced by Palma bay. The improvement of the bathymetry grid resolution in the bay and harbor domains and the inclusion in the simulations of the exact harbor geometry and internal configuration result in a slight wave-high increment that is much below the wave height recorded in the tide gauge. Our results strongly point to a necessary revision of the tsunami seismic source parameters

Comentarios alrededor de 1789 pruebas de uropepsina

Se presenta la experiencia con uropepsina; 1789 pruebas realizadas y 390 casos, completamente estudiados. Se hace un comentario sobre la casuística general, las cifras promedio y las cifras medias encontrada entre nosotros. En los normales esta es de 29.9. En la úlcera gástrica 62.9. En la duodenal 85.8. En el cáncer gástrico 19.1. Se explica la técnica empleada, que es la de goodman a la cual le introducimos modificaciones originales: La utilización de controles positivos y negativo, que hacen más segura la interpretación de los resultados. Se presentan los experimentos practicados con un ganglio metastásico, de los cuales se deduce que allí se encontró un zimógeno con todos los caracteres del pepsinógeno. Se recalca en el valor pronóstico de la prueba de la uropepsina, especialmente en la úlcera duodenal y en el carcinoma gástrico. La aparición de uropepsina después de gastrectomía total por cáncer, indica la presencia de metástasis. El tipo de gastrectomía que da cifras más bajas y persistentes de uropepsina es la fundo-corporal. El ACTH estimula la producción de pepsinógeno en individuos normales, gastrectomizados tipo billroth y gastrectomizados totales con metástasis