Biogeografía de los parásitos sanguíneos en un hospedador aviar modelo con diversas estrategias migratorias: la curruca capirotada "Sylvia atricapilla"

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Biológicas, Departamento de Zoología y Antropología Física, leída el 17/09/2013The negative effects that parasites have on their hosts’ fitness make of parasitism one of the main evolutive agents. The knowledge of which are the factors that determine the spatiotemporal distribution of parasites impacts is hence critical if we are to anticipate the threat posed by emergent diseases in a context of global change. This PhD Thesis used the blackcap Sylvia atricapilla (Aves: Sylviidae) and its haemosporidian parasites (genera Plasmodium, Haemoproteus y Leucocytozoon; Apicomplexa) as a model system to test how several sources of environmental variation determine the differences on parasite impacts. First we identified which variables in an Iberian context were the main determinants of parasite diversity, finding out that although climatic variables (mainly temperature) were the most relevant ones, including orographic variables into the analyses increased their significance. Then we used this information to predict the current and future distribution of the areas under a strong parasitic pressure in the Iberian Peninsula, forecasting a future reshuffling of the current host-parasite relationships mosaic. We also performed a reconstruction of how different strategies of seasonal transmission (summer transmission, extended summer transmission and year-round transmission) have evolved through the evolutionary history of these parasites, discovering that, although year-round transmission has appeared multiple independent times and it is an ecologically successful strategy, it is not as successful as seasonal transmission in the long run. Finally, by examining the parasitic communities of the blackcaps inhabiting the archipelagos of the Canay Islands and Madeira, we found out that host-parasite relationships are compromised in insular environments, and that insular syndromes (low richness, host switching and host generalism) develop among parasites even before the development of full isolation.Los efectos negativos que los parásitos tienen sobre la eficacia biológica de sus hospedadores hacen del parasitismo uno de los principales agentes evolutivos. Por esta razón, conocer los factores que determinan la distribución espacial y temporal del impacto de los parásitos es crítico para anticiparnos a los problemas que las enfermedades emergentes pueden provocar en un contexto de cambio climático. Esta tesis emplea la curruca capirotada Sylvia atricapilla (Aves: Sylviidae) y sus parásitos sanguíneos hemosporidios (géneros Plasmodium, Haemoproteus y Leucocytozoon; Apicomplexa) como modelo de estudio para examinar cómo diversas fuentes de variación ambiental determinan las diferencias en el impacto de los parásitos. Se identificaron primero qué variables tienen mayor importancia en un contexto ibérico como determinantes de la diversidad de parásitos, encontrándose que si bien las variables ambientales (temperatura principalmente) son las más importantes, los modelos mejoran significativamente si se incluyen variables orográficas. Se usaron luego estos datos para examinar la distribución actual y la esperada a finales del S. XXI bajo tres escenarios de cambio climático de las zonas sujetas a un mayor impacto de estos parásitos en la Península, evidenciándose una reestructuración futura del mosaico actual de relaciones entre parásitos y hospedadores. Se realizó también una reconstrucción de cómo han evolucionado diferentes estrategias de transmisión estacional (transmisión estival, transmisión estival expandida y transmisión continua) a lo largo de la historia evolutiva de estos parásitos, encontrándose que paradójicamente la estructura ecológicamente más exitosa (transmisión continua) no es la más exitosa a largo plazo (transmisión estival). Finalmente, examinando las comunidades de parásitos de las currucas de Canarias y Madeira se descubrió que las relaciones parásito-hospedador habituales se ven comprometidas en ambientes insulares, y de que los síndromes insulares del parasitismo (riqueza baja, frecuentes cambios de hospedador y tendencia al generalismo) pueden desarrollarse incluso en la ausencia de aislamiento completo.Depto. de Biodiversidad, Ecología y EvoluciónFac. de Ciencias BiológicasTRUEunpu

An AER Spike-Processing Filter Simulator and Automatic VHDL Generator Based on Cellular Automata

Spike-based systems are neuro-inspired circuits implementations traditionally used for sensory systems or sensor signal processing. Address-Event- Representation (AER) is a neuromorphic communication protocol for transferring asynchronous events between VLSI spike-based chips. These neuro-inspired implementations allow developing complex, multilayer, multichip neuromorphic systems and have been used to design sensor chips, such as retinas and cochlea, processing chips, e.g. filters, and learning chips. Furthermore, Cellular Automata (CA) is a bio-inspired processing model for problem solving. This approach divides the processing synchronous cells which change their states at the same time in order to get the solution. This paper presents a software simulator able to gather several spike-based elements into the same workspace in order to test a CA architecture based on AER before a hardware implementation. Furthermore this simulator produces VHDL for testing the AER-CA into the FPGA of the USBAER AER-tool.Ministerio de Ciencia e Innovación TEC2009-10639-C04-0

FPGA Implementations Comparison of Neuro-cortical Inspired Convolution Processors for Spiking Systems

Image convolution operations in digital computer systems are usually very expensive operations in terms of resource consumption (processor resources and processing time) for an efficient Real-Time application. In these scenarios the visual information is divided in frames and each one has to be completely processed before the next frame arrives. Recently a new method for computing convolutions based on the neuro-inspired philosophy of spiking systems (Address-Event-Representation systems, AER) is achieving high performances. In this paper we present two FPGA implementations of AERbased convolution processors that are able to work with 64x64 images and programmable kernels of up to 11x11 elements. The main difference is the use of RAM for integrators in one solution and the absence of integrators in the second solution that is based on mapping operations. The maximum equivalent operation rate is 163.51 MOPS for 11x11 kernels, in a Xilinx Spartan 3 400 FPGA with a 50MHz clock. Formulations, hardware architecture, operation examples and performance comparison with frame-based convolution processors are presented and discussed.Ministerio de Ciencia e Innovación TEC2006-11730-C03-02Junta de Andalucía P06-TIC-0141

On the AER Convolution Processors for FPGA

Image convolution operations in digital computer systems are usually very expensive operations in terms of resource consumption (processor resources and processing time) for an efficient Real-Time application. In these scenarios the visual information is divided into frames and each one has to be completely processed before the next frame arrives in order to warranty the real-time. A spike-based philosophy for computing convolutions based on the neuro-inspired Address-Event- Representation (AER) is achieving high performances. In this paper we present two FPGA implementations of AER-based convolution processors for relatively small Xilinx FPGAs (Spartan-II 200 and Spartan-3 400), which process 64x64 images with 11x11 convolution kernels. The maximum equivalent operation rate that can be reached is 163.51 MOPS for 11x11 kernels, in a Xilinx Spartan 3 400 FPGA with a 50MHz clock. Formulations, hardware architecture, operation examples and performance comparison with frame-based convolution processors are presented and discussed.Ministerio de Ciencia e Innovación TEC2006-11730-C03-02Ministerio de Ciencia e Innovación TEC2009-10639-C04-02Junta de Andalucía P06-TIC-0141

Application of Robot Programming to the Teaching of Object-Oriented Computer Languages

Object-oriented programming (OOP) abstract concepts are often difficult to understand for students, since it is not easy to find the equivalence of such concepts in daily life. In this paper we will study if an interdisciplinary approach based on an introduction to robotics and robot programming helps the student in acquiring theOOPconcepts. For our experiments, we selected a sample of thirty individuals among students with an adequate knowledge of procedural programming. This sample was divided into two groups of fifteen students each: for the first one we used a standard introductory approach to C#, whereas for the second one we developed an experimental course that included a demonstration program that illustrated OOP basic concepts using the features of a specific type of commercial ball-shaped robot with sensing, wireless communication and output capabilities. After the courses, both groups were evaluated by completing a multiple-choice exam and aC#programming exercise. Our results show that the student group that attended the course including the robot demo showed a higher interest level (i.e. they felt more motivated) than those students that attended the standard introductory C# course. Furthermore, the students from the experimental group also achieved an overall better mark

AER tools for Communications and Debugging

Address-event-representation (AER) is a communications protocol for transferring spikes between bio-inspired chips. Such systems may consist of a hierarchical structure with several chips that transmit spikes among them in real time, while performing some processing. To develop and test AER based systems it is convenient to have a set of instruments that would allow to: generate AER streams, monitor the output produced by neural chips and modify the spike stream produced by an emitting chip to adapt it to the requirements of the receiving elements. In this paper we present a set of tools that implement these functions developed in the CAVIAR EU projectUnión Europea IST-2001-34124 (CAVIAR)Ministerio de Ciencia y Tecnología TIC-2003-08164-C03-0

Prevalence of new and known species of haemoparasites in feral pigeons in northwest Italy

Background: Haemoparasites in feral pigeons have been studied in several countries but no data are available from Italy. The aim of this work was to evaluate the prevalence and diversity of Haemoproteus spp./Plasmodium spp. and Leucocytozoon spp. in feral pigeons from northwest Italy, as well as the association between infection and host age or sex. Methods: Feral pigeons were collected during a regional culling programme from the Piedmont region (northwest Italy) and subjected to necropsy. Infections were detected from DNA extracted from the spleen following a nested PCR protocol. The association between sex or age and infection status was evaluated using the chi-squared test for independence or Fisher’s exact test. Results: Out of 51 animals, 15 were positive for Haemoproteus/Plasmodium spp. and eight for Leucocytozoon spp., with a significant difference between haemoparasites prevalence. There was no significant association between age or sex and infection status. The coinfection with different haemoparasites was very significant (p < 0.01), showing a greater relative risk to be infected by a second haemoparasite in birds already infected, in particular in male and in adult pigeons. DNA sequencing of Leucocytozoon spp. showed six different lineages in pigeons, and one of Haemoproteus and Plasmodium, respectively. Conclusions: Blood parasites are continuously circulating around the world, and the results presented in the paper suggest that cross infection of feral pigeons with haemoparasites typical of other migratory or nonmigratory bird species is possible. Moreover, the geographical location of Italy along the main migratory routes is a crucial factor to be considered for migratory birds, because they can be affected by blood parasites detected in feral pigeons, and vice versa

Development of Gold Nanoparticle-Doped Activated Carbon Sorbent for Elemental Mercury

The control of mercury (Hg) from coal-fired power plants by adsorption in solid sorbents is an attractive way to reduce Hg emissions. In this study, a commercial activated carbon (Norit RB3) was impregnated with gold nanoparticles for the retention of Hg in the gas phase, with the intention to explore their potential to be regenerated in future investigations. The activated carbon (RB3) was impregnated with different gold contents using polyvinyl alcohol (PVA) and tetrakis(hydroxymethyl)phosphonium chloride (THPC) to compare the performance of these two methods. Gold particles of ∼5 nm were obtained in the carbonaceous support for low gold contents (0.1%). With comparative purposes of the sorbent behavior, the Hg0 retention capacity was evaluated in a lab-scale device in an O2 + N2 atmosphere. Although the Hg retention capacities of these sorbents were similar by the two methods, a higher efficiency was achieved with THPC, being in some cases 80%. The results showed that the use of THPC is a promising means for dropping gold (0.1%) to make carbonaceous sorbents for use in Hg capture.The authors thank the CSIC (PIF-06-050) and the Spanish Ministerio de Ciencia e Innovación (CTQ2008-06860-C02-01) for financial support.Peer reviewe

There is more to the picture than meets the eye: adaptation for crypsis blurs phylogeographical structure in a lizard

Aim: We examined dorsal coloration in and genetic relationships among Iberian populations of the lizard Psammodromus algirus to determine the extent to which the current distribution of phenotypic variation is correlated with phylogeographical history or local environmental conditions. Location: Iberian Peninsula, western Palaearctic.Methods: We sequenced mitochondrial DNA (ND4 and adjacent tRNAs genes) in 36 populations, and seven microsatellite loci in eight representative populations. In 23 populations, lizards were classified according to the presence and intensity of a dorsal striped pattern, the heritability of which was estimated by means of mother–offspring regressions. To determine whether colour pattern is an adaptation for crypsis, we compared the time taken by humans to detect striped and unstriped lizards in different environments.Results: The analysis of mtDNA revealed an ancient split between a western clade, subdivided into south- and north-western haplogroups, and an eastern clade with central, south-eastern and eastern haplogroups. In contrast, nuclear markers showed a post-glacial admixture of central and western haplogroups, with the central haplogroup apparently isolated from the rest of its clade. This was consistent with variation in the dorsal striped pattern, a heritable phenotypic trait: central and western lizards were unstriped, whereas eastern lizards were striped. We then suggest that dorsal coloration promotes crypsis: in eastern locations detection times were longer for striped than for unstriped lizards, whereas the opposite was true in western and central locations.Main conclusions: Our results indicate that natural selection for crypsis may promote not only divergence within clades, as suggested by the apparent isolation between unstriped central lizards and striped members of eastern haplogroups, but also admixture between them. We conclude that ecologically driven selection is crucial for understanding the phylogeographical background of phenotypic variation, because recent adaptation to the environment can blur the effects of ancestral isolation.This study is a contribution to projects CGL2010-17928/BOS and CGL2013-41642-P, funded by the Spanish Ministry of Education and SciencePeer reviewe