Impact of the interactions between hosts vectors and pathogens on the transmission of avian malaria and flavivirus by mosquitoes.

Vector-borne pathogens cause important diseases such as malaria and are nowadays a major public health concern, because they cause human –and animal- fatalities worldwide and have a significant impact on local economies. Factors associated to global change, such as habitat alteration and introduction of invasive species, have largely contributed to the spread of potential insect vectors and the pathogens they are able to transmit, thus creating novel epidemiological scenarios. Therefore, it becomes essential to study the factors that modulate the transmission risk of these disease agents involving the interactions between vertebrate hosts (humans and other animals), pathogens and insect vectors in natural ecosystems. In this thesis, I used a multidisciplinary approach combining molecular tools, experimental bioassays and statistical analyses to assess the ecological and evolutionary factors that affect the transmission success of two mosquito-borne pathogens. In particular, I considered the interactions between insect vectors, vertebrate hosts, the avian malaria parasites and the flavivirus Zika virus. I focused on two major steps directly influencing the pathogen transmission success: i) the contact rate between mosquitoes and infected/susceptible vertebrate hosts and ii) the development of the pathogen in the mosquito and its consequences on the pathogen transmission risk. To do that, first I tested the potential causes underlying differences in the biting patterns of mosquito species. I exposed two bird species to two mosquito species to determine the role of mosquito species identity and effect of three host-related factors on host-vector contact rates (i.e. body mass, gender, and infection status by avian malaria). I found clear interspecific differences in the biting rates of mosquitoes, which were also influenced by variation in hosts’ traits, although these effects differed depending on the particular mosquito-host assemblage. Therefore, the biting patterns of mosquitoes are far from being generalizable. Secondly, I assessed the vector competence of different mosquito species for the transmission of Zika virus and avian malaria using mosquito saliva. I found that the ability of mosquito-borne pathogens to develop in mosquitoes differed between insect species, which may be the result of complex co-evolutionary processes. In addition, I assessed the consequences of parasite development in the mosquito vectors and their implications for the pathogen transmission risk. I found that host parasite load and parasite identity play affect the impact of parasites on mosquito longevity finally determining the transmission risk of the parasites. With this information mostly derived from studies under controlled conditions, I assessed the importance of environmental conditions affecting the host-parasite-vector assemblages in the wild. I found that habitat characteristics, which determine the existence and abundance of insect vectors, and host related factors (i.e. immune-competence) determines the prevalence of avian malaria parasites in insular ecosystems. Altogether, in this thesis I identified key factors affecting the transmission success of vector-borne pathogen affecting humans or wildlife allowing a better understanding the complex transmission dynamics of vector-borne pathogens.Los patógenos transmitidos por vectores que causan enfermedades importantes como la malaria son a día de hoy un importante problema de salud pública, ya que causan numerosas muertes humanas y animales en todo el mundo teniendo un gran impacto en la economía local. Factores asociados al cambio global, así como la alteración del hábitat y la introducción de especies invasoras, han contribuido en gran medida a la expansión de posibles insectos vectores y de patógenos que pueden transmitir, creándose nuevos escenarios epidemiológicos. Por lo tanto, es esencial estudiar aquellos factores que influyen en el riesgo de transmisión de estos patógenos considerando las interacciones entre los huéspedes vertebrados (humanos y otros animales), los patógenos insectos vectores en los ecosistemas naturales. En esta tesis, mediante un enfoque multidisciplinario que combina herramientas moleculares, bioensayos experimentales y análisis estadísticos, se evalúan los factores ecológicos y evolutivos que afectan al éxito de transmisión de dos patógenos transmitidos por mosquitos. En particular, se consideraron las interacciones entre los parásitos de la malaria aviar y el virus (flavivirus) del Zika.y sus insectos vectores y hospedadores vertebrados, En concreto, me centro en dos procesos principales que influyen directamente en el éxito de la transmisión de patógenos: i) la tasa de contacto entre mosquitos y hospedadores vertebrados infectados/susceptibles y ii) el desarrollo del patógeno en el mosquito y sus consecuencias sobre el riesgo de transmisión de estos. Para ello, primero estudié las posibles causas que subyacen a las diferencias en los patrones de alimentación de las especies de mosquitos. Se expusieron dos especies de pájaros a dos especies de mosquitos para determinar el papel de la especie de mosquito y el efecto de tres factores relacionados con el hospedador vertebrado sobre las tasas de contacto entre el hospedador y el vector (masa corporal, género e infección por parásito de la malaria aviar). Encontré claras diferencias inter-específicas en las tasas de picadura de los mosquitos, que también se vieron influenciadas por la variación en los rasgos de los hospedadores, aunque estos efectos difirieron dependiendo de la asociación mosquito hospedador. Por lo tanto, los patrones de alimentación de los mosquitos parecen estar lejos de ser generalizables. En segundo lugar, estudié la competencia vectorial de diferentes especies de mosquitos para la transmisión del virus del Zika y de parásitos de la malaria aviar utilizando la saliva del mosquito. Descubrí que la capacidad de desarrollo de los patógenos difería entre las especies de mosquitos, pudiendo esto ser el resultado de complejos procesos coevolutivos. Además, evalué las consecuencias que tiene el desarrollo de los parásitos en los mosquitos en el riesgo de transmisión de estos. También encontré que tanto la carga parasitaria del hospedador vertebrado como la identidad del parásito afectan a la longevidad de los mosquitos y consecuentemente determina el riesgo de transmisión de los parásitos. Con esta información, derivada principalmente de estudios en laboratorio, con condiciones controladas, evalué como afectan las condiciones ambientales a las asociaciones entre hospedador-parásito-vector en la naturaleza. Descubrí que las características del hábitat, las cuales van a determinan la existencia y abundancia de insectos vectores, así como los factores relacionados con el huésped (inmunocompetencia), determinan la prevalencia de parásitos de la malaria aviar en los ecosistemas insulares.Premio Extraordinario de Doctorado U

Cue duration modulates the effects produced by a change in cue-outcome contingencies

Presentación en el XXV Congreso de la Sociedad Española de Psicología ComparadaLas investigaciones sobre aprendizaje humano de contingencias se han centrado en estudiar si se ponen en marcha procesos asociativos, además de procesos inferenciales de aprendizaje, en este tipo de tareas. En general se ha tratado de disociar estos dos tipos de procesos dentro de una misma tarea. Sin embargo, es posible que dependiendo de las características de la tarea, se ponga en marcha un tipo de proceso u otro, pero no los dos al mismo tiempo. Una de las características que se considera que diferencia entre estos dos tipos de procesos, es el tiempo disponible para procesar los estímulos. Una presentación breve impide (o dificulta) la puesta en marcha de procesos inferenciales. Una presentación larga los favorece. En la investigación se utilizó una tarea de respuesta señalada con dos fases de aprendizaje (F1 y F2). En F1 se presentaron cuatro estímulos diferentes seguidos de un mismo outcome. En F2 se cambiaron los emparejamientos estímulo-outcome de dos de los estímulos. Mediante instrucciones colocadas entre F1 y F2, se informó del cambio de emparejamiento de uno de estos estímulos, mientras que el otro cambio fue inesperado. Se comparó el efecto de las instrucciones en F2 utilizando tres grupos de sujetos. En un grupo, la presentación de estímulos fue muy corta (250 ms) en F1 y F2. En otro grupo, la presentación de estímulos fue larga (1500 ms). En el tercer grupo, los estímulos se presentaron durante 250 ms en F1 y 1500ms en F2. Los resultados sugieren la influencia de procesos asociativos en F2 únicamente cuando la presentación de estímulos fue de 250 ms.Proyecto Junta de Andalucía SEJ2008-SEJ3586 Proyecto Ministerio de Ciencia e Innovación PSI2011-2466

Sistemas front-end integrados para la detección de partículas cargadas aplicando técnicas de incremento de ganancia

En este trabajo de investigación, se han propuesto y aplicado técnicas de incremento de ganancia en diseño analógico para implementar varios sistemas front-end utilizados en aplicaciones de física nuclear para la detección de partículas cargadas mediante detectores semiconductores de silicio. En los últimos años se ha incrementado el número de trabajos relacionados con la integración de estos sistemas front-end en tecnologías CMOS para cubrir ia necesidad de acondicionar y procesar la señal de centenares e incluso miies de canales de los nuevos sistemas de detección. Las ventajas relacionadas con ia alta densidad de integración y el bajo consumo de potencia, debe hacer frente a desafíos de diseño relacionados con la degradación de los parámetros analógicos de ios transistores debido ai escalado de ia tecnología, tales como la pérdida de ganancia intrínseca y el incremento de ruido. La tesis propone soluciones de circuito para incrementar ia ganancia de ios elementos activos que constituyen los bloques constructivos de la parte analógica de un sistema front-end, esto es, amplificadores sensibles a ia carga y conformadores de pulso o shapers, de forma que se asegure su correcto funcionamiento operando en iazo cerrado y usando tecnologías CMOS submicrométricas. Los diseños abordan cuestiones relacionadas con el ruido, consumo de potencia, área de silicio, rango dinámico, precisión, linealidad y velocidad. Todos los sistemas impiementados en esta tesis han sido fabricados usando tecnologías CMOS n-weil de 130 nm y de 90 nm. Los resultados de las medidas experimentales son presentados y analizados en cada caso para validar el funcionamiento del correspondiente diseño.In this research work, gain enhancement techniques for analog design have been proposed and applied to implement several front-end electronics systems used in nuclear physics applications for detection of charged particles through silicon semiconductor detectors. In recent years the number of works related to the integration of these front-end systems in CMOS technologies has increased to meet the need of signal conditioning and processing from hundreds and even thousands of channels of new detection systems. The advantages related to the high density of integration and low power consumption, must face design challenges related to the degradation of the analog parameters of transistors due to the technology scaling-down, such as the low of intrinsic gain and the increase in noise. This thesis proposes circuit solutions to increase the gain of the active elements that constitute the building blocks of the analog part of a front-end system, i.e. charge sensitive amplifiers and shapers, to ensure their proper closed-loop operation and using submicron CMOS technologies. The designs addressed issues related to noise, power consumption, silicon area, dynamic range, precision, linearity and speed. All the systems implemented in this thesis have been fabricated using 130 nm and 90 nm n- well CMOS process technology. The results of experimental measurements are presented and analyzed in each case to validate the operation of the corresponding design

Using transparent WDM metro rings to provide an out-of-band control network for OpenFlow in MAN

OpenFlow is a protocol that enables networks to evolve and change flexibly, by giving a remote controller the capability of modifying the behavior of network devices. In an OpenFlow network, each device needs to maintain a dedicated and separated connection with a remote controller. All these connections can be described as the OpenFlow control network, that is the data network which transports control plane information, and can be deployed together with the data infrastructure plane (in-band) or separated (out-of-band), with advantages and disadvantages in both cases. The control network is a critical subsystem since the communication with the controller must be reliable and ideally should be protected against failures. This paper proposes a novel ring architecture to efficiently transport both the data plane and an out-of-band control network.The authors would like to acknowledge the support of the Spanish projects CRAMnet (grant no. TEC2012-38362-C03-01) and FIERRO (grant no. TEC2010-12250-E) to the development of this work

Factores estructurales de la pared celular del forraje que afectan su digestibilidad

La naturaleza de enlaces cruzados de los componentes de la pared celular y la cantidad de lignina y taninos condensados pueden ser los factores clave que limiten su degradación; sin embargo, la organizaci ón de la matriz puede regular el grado de influencia de la lignina sobre la degradación de los polisacáridos de la pared. Su efecto parece no ser igual en arbustos y pastos. El impedimento estérico parece ser el mecanismo principal que limita la degradación. Esto parece aplicarse a arbustos nativos de zonas áridas, la identificación de factores limitantes específicos, como la lignina y los taninos, pueden contribuir a incrementar la utilización de la energía de la pared celular del forraje

13. Integrating information on the role of mosquitoes for the transmission of pathogens of wildlife

Traditionally, mosquitoes have been studied given their relevance as vectors of pathogens that affect humans. However, in recent decades, their relevance as vectors of pathogens that affect wildlife has become evident. For this reason, multidisciplinary research disciplines have been developed focusing on the ecology, epidemiology and evolution of the interactions between pathogens and their hosts, including the transmission dynamics of diseases. However, there is a gap in the knowledge of mosquito-borne pathogens that affect wildlife, being necessary to study the taxa diversity, using genomic tools and, of course, their life cycles and their vectors. However, the information on the vector competence of mosquitoes for the transmission of pathogens that affect wild animals is certainly scarce. Interspecific and intraspecific differences have been evidenced. This would determine the capacity of mosquitoes to transmit parasites that infect wild animals. Different factors such as physiological and biochemical processes, or the mosquito microbiota could determine these differential capacities of mosquitoes to transmit pathogens.RGL was partially supported by a Margalida Comas contract from the Government of the Balearic Islands co-financed by the European Regional Development Fund (FEDER) (REF: PD/038/2019) and a Juan de la Cierva Formación contract (REF: FJC2019-041291-I). JMP was financed by the project PID2020-118205GB-I00 from the Spanish Ministry of Science and Innovation co-financed by the European Regional Development Fund (FEDER)

The effect of verbal instructions in contingency learning depends on the time available to process the cue: evidence in favor of associative models

Much of the research in human contingency learning has tried to dissociate associative and inferential processes. One feature that has been regarded as relevant for these dissociations is the time available to process the cue. A brief presentation of the cue may facilitate the activation of associative processes whereas a long one may favor the activation of inferential processes. The two experiments reported here used a two-phase task. In Phase 1, four different cue-outcome relationships were programmed. In Phase 2, two of these relationships were changed. Participants knew about some of these changes through verbal instructions. The effect of these instructions was measured during Phase 2 in two groups that differed in the time available to process the cue, either 250 or 1500 ms. The results showed that the control of performance produced by verbal instructions differed depending on the time available to process the cue. Only in the 1500 ms group, the verbal instructions were able to affect what it had been learnt during Phase 1. Thus, the results are consistent with the hypothesis that a brief presentation of the cue during Phase 2 facilitates the activation of associative processesUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Proyecto MICIN Proyecto PSI 2011-2466

Troubleshooting PON networks effectively with carrier-grade ethernet and WDM-PON

WDM-PONs have recently emerged to provide dedicated and separated point-to-point wavelengths to individual optical network units. In addition, the recently standardized Ethernet OAM capabilities under the IEEE 802.1ag standard and ITU-T Recommendation Y.1731, together with state-of-the-art optical timedomain reflectometry provide new link-layer and physical tools for the effective troubleshooting of WDM-PONs. This article proposes an integrated troubleshooting box (ITB) for the effective combination of both physical and link-layer information into an effective and efficient set of management procedures for WDM-PONs. We show its applicability in a number of realistic troubleshooting scenarios, including failure situations involving either the feeder fiber, one of its branches, or even Ethernet links after the ONU.The authors would like to acknowledge the support of the CRAMnet project, funded by the Spanish government under grant no. TEC2012-38362-C03-01, to the development of this work. Also, the authors would like to thank Mr. Russ Jones from Ericsson-LG for his valuable support, especially concerning the laboratory trial setup of an earlier section

Methodological procedures explain observed differences in the competence of European populations of Aedes albopictus for the transmission of Zika virus

The risk of autochthonous transmission of Zika virus (ZIKV) in Europe greatly depends on the capacity of Aedes albopictus to transmit ZIKV. Experimental studies of the vector competence of European populations of this invasive mosquito species provided contrasting results, that may suggest differences between mosquito populations in ZIKV competence and/or differences in the methodological procedures used on the experimental studies. We systematically reviewed published studies of experimental mosquito infections and show that differences detected in the infection and transmission rates of Ae. albopictus are mostly due to differences between studies in the temperature, the viral load used to inoculate mosquitoes, and the number of days post-exposure (dpe) to the virus at which mosquitoes were analysed. In particular, the proportion of infected mosquitoes was affected by the viral load inoculated and the dpe, whereas the transmission rate was influenced by the viral load and temperature. Thus, the methodological differences used in these studies greatly affect the conclusions obtained regarding the role of Ae. albopictus in Europe as a competent vector for ZIKV and its epidemiological relevance

Network Planning for Dual Residential-Business Exploitation of Next-Generation Passive Optical Networks to Provide Symmetrical 1 Gb/s Services

Demand for high-speed access for business and residential subscribers has grown rapidly in recent years; thus, service providers need to offer cost-effective solutions to cover this demand. Convergence within the same infrastructure for clients requiring different service levels may have benefits in terms of cost, but their respective service-level specifications need to be guaranteed. This article compares different flavors of next-generation passive optical networks (PONs), namely, gigabit PON (GPON), 10-gigabit PON (XG-PON), time and wavelength division multiplexing PON (TWDM-PON), and wavelength division multiplexing PON (WDM-PON), and evaluates which one can provide 1 Gb/s symmetrical service at the more affordable cost when there is a mix of residential and business subscribers. Results show that the recommended technology depends on the percentage of business subscribers in the scenario.The authors would like to acknowledge the support of the Spanish projects CRAMnet (grant no. TEC2012-38362-C03-01), Elastic Networks (grant no. TEC2015-71932-REDT), TIGRE-5CM (grant no. S2013/ICE-2919), and Fed4FIRE EU Project 318389 for the development of this work. The views expressed in this article are those of the authors and do not reflect the opinion of the authors’ employers, specifically in terms of architectural and engineering design or experience.European Community's Seventh Framework Progra