Characterization of an antennal carboxylesterase from the pest moth Spodoptera littoralis degrading a host plant odorant.

Background: Carboxyl/cholinesterases (CCEs) are highly diversified in insects. These enzymes have a broad range of proposed functions, in neuro/developmental processes, dietary detoxification, insecticide resistance or hormone/pheromone degradation. As few functional data are available on purified or recombinant CCEs, the physiological role of most of these enzymes is unknown. Concerning their role in olfaction, only two CCEs able to metabolize sex pheromones have been functionally characterized in insects. These enzymes are only expressed in the male antennae, and secreted into the lumen of the pheromone-sensitive sensilla. CCEs able to hydrolyze other odorants than sex pheromones, such as plant volatiles, have not been identified. Methodology: In Spodoptera littoralis, a major crop pest, a diversity of antennal CCEs has been previously identified. We have employed here a combination of molecular biology, biochemistry and electrophysiology approaches to functionally characterize an intracellular CCE, SlCXE10, whose predominant expression in the olfactory sensilla suggested a role in olfaction. A recombinant protein was produced using the baculovirus system and we tested its catabolic properties towards a plant volatile and the sex pheromone components. Conclusion: We showed that SlCXE10 could efficiently hydrolyze a green leaf volatile and to a lesser extent the sex pheromone components. The transcript level in male antennae was also strongly induced by exposure to this plant odorant. In antennae, SlCXE10 expression was associated with sensilla responding to the sex pheromones and to plant odours. These results suggest that a CCE-based intracellular metabolism of odorants could occur in insect antennae, in addition to the extracellular metabolism occurring within the sensillar lumen. This is the first functional characterization of an Odorant- Degrading Enzyme active towards a host plant volatile.

Trophic structure in a seabird host-parasite food web: insights from stable isotope analyses

Ecological studies on food webs rarely include parasites, partly due to the complexity and dimensionality of host-parasite interaction networks. Multiple co-occurring parasites can show different feeding strategies and thus lead to complex and cryptic trophic relationships, which are often difficult to disentangle by traditional methods. We analyzed stable isotope ratios of C (13C/12C, δ13C) and N (15N/14N, δ15N) of host and ectoparasite tissues to investigate trophic structure in 4 co-occurring ectoparasites: three lice and one flea species, on two closely related and spatially segregated seabird hosts (Calonectris shearwaters). δ13C isotopic signatures confirmed feathers as the main food resource for the three lice species and blood for the flea species. All ectoparasite species showed a significant enrichment in δ15N relatively to the host tissue consumed (discrimination factors ranged from 2 to 5 depending on the species). Isotopic differences were consistent across multiple host-ectoparasite locations, despite of some geographic variability in baseline isotopic levels. Our findings illustrate the influence of both ectoparasite and host trophic ecology in the isotopic structuring of the Calonectris ectoparasite community. This study highlights the potential of stable isotope analyses in disentangling the nature and complexity of trophic relationships in symbiotic systems.

Television and the construction of identity: Barcelona, Olympic host

This document, originally published as part of the book The Keys of success: the social, sporting, economic and communications impact of Barcelona’92, comes from a larger study that looked at all aspects of television in the Olympics and can be found in its original version, in Miquel de Moragas Spà, Nancy K. Rivenburgh and James F. Larson (1996). Television in the Olympics. London: John Libbey.

The relationships between technology and open education in the development of a resilient higher education

The place of technology in the development of coherent educational responses to environmental and socio-economic disruption is here placed under scrutiny. One emerging area of interest is the role of technology in addressing more complex learning futures, and more especially in facilitating individual and social resilience, or the ability to manage and overcome disruption. However, the extent to which higher education practitioners can utilise technology to this end is framed by their approaches to the curriculum, and the socio-cultural practices within which they are located. This paper discusses how open education might enable learners to engage with uncertainty through social action within a form of higher education that is more resilient to economic, environmental and energy-related disruption. It asks whether open higher education can be (re)claimed by users and communities within specific contexts and curricula, in order to engage with an uncertain world.

Some biological data on cetaceans populations present in the western coasts of Ireland

Ireland’s waters constitute one of the richest habitats for cetaceans in Europe. Marine mammals, particularly cetaceans, are known to be definitive hosts of digestive parasites from the Fm.Anisakidae. The main aim of this study is to collect and compile all the information available out there regarding parasites of the Fm. Anisakidae and their definitive hosts. Secondary objectives are to relate the presence of cetacean species with the presence of parasites of the Fm. Anisakidae and to determine whether this greater number of cetaceans relates to a greater level of parasitism. Prevalence and burdens of anisakids in definitive hosts vary widely with host species, geographic location, and season. Results from several post-mortem exams are given. However, they cannot be compared due to differences in collecting techniques. Anisakis simplex is the most commonly and widespread parasite found in the majority of the samples and in a majornumber of hosts, which include harbour porpoise, short-beaked common dolphin and bottlenose dolphin. Studies on harbour porpoise obtained prevalences of Anisakis spp. of 46% (n=26) and of 100% (n= 12). Another study in common dolphin reported a prevalence of 68% (n=25). Several reasons could influence the variations in the presence of Anisakis. Studies on commerciallyexploited fish have reported prevalences of Anisakis simplex ranging from 65-100% in wildAtlantic salmon and from 42-53.4% in Atlantic cod

A continuous strain-space model of viral evolution within a host

Viruses rapidly evolve, and HIV in particular is known to be one of the fastest evolving human viruses. It is now commonly accepted that viral evolution is the cause of the intriguing dynamics exhibited during HIV infections and the ultimate success of the virus in its struggle with the immune system. To study viral evolution, we use a simple mathematical model of the within-host dynamics of HIV which incorporates random mutations. In this model, we assume a continuous distribution of viral strains in a one-dimensional phenotype space where random mutations are modelled by di ffusion. Numerical simulations show that random mutations combined with competition result in evolution towards higher Darwinian fitness: a stable traveling wave of evolution, moving towards higher levels of fi tness, is formed in the phenoty space.

New stakeholders, spaces and instruments of analysis in the context of energy relationships: Case studies from Kazakhstan and Turkmenistan

The disintegration of the USSR brought the emergence of a new geo-energy space in Central Asia. This space arose in the context of a global energy transition, which began in the late 1970s. Therefore, this new space in a changing energy world requires both new conceptual frameworks of analysis and the creation of new analytical tools. Taking into account this fact, our paper attempts to apply the theoretical framework of the Global Commodity Chain (GCC) to the case of natural resources in Central Asia. The aim of the paper is to check if there could be any Central Asia’s geo-energy space, assuming that this space would exist if natural resources were managed with regional criteria. The paper is divided into four sections. First an introduction that describes the new global energy context within natural resources of Central Asia would be integrated. Secondly, the paper justifies why the GCC methodology is suitable for the study of the value chains of energy products. Thirdly, we build up three cases studies (oil and uranium from Kazakhstan and gas from Turkmenistan) which reveal a high degree of uncertainty over the direction these chains will take. Finally, we present the conclusions of this study that state that the most plausible scenario would be the integration of energy resources of these countries in GCC where the core of the decision-making process will be far away from the region of Central Asia. Key words: Energy transition, geo-energy space, Global Commodity Chains, Central Asia

The relationships of stress, health and wellbeing among workers

The precise relationship between the positive psychological state of work (i.e. engagement ) and the negative psychological state (i.e. burnout) has recently received research attention. Some view these as opposite states on the same similar continuum, while others take the position that they represent different biobehavioral spheres. This study expands our knowledge of the phenomenta engagement and burnout by analyzing their separate and joint manifestations. Using a sample of 2094 nurses, respondents were analyzed to determine the configuration of antecedents leading to separate and joint states of engagement and burnout, the configuration of engagement and burnout leading to mental, physical and organizational outcomes, and the relationship between engagement, bornout, and risk of metabolic syndrome. The study found that while both work engagement and burnout are highly correlated to health and organizational outcomes, the relative statistical power of burnout has a greater direct effect on health. It is important for workers and managers to adress the sources of burnout before addressing the positive psychological aspects of worker engagement.

Incidència de l’entorn educatiu, familiar i social en les actituds lingüístiques i identitàries dels joves d’origen xinès i llatinoamericà a Catalunya

From an interdisciplinary perspective, the present investigation undertaken by the GREILI-UPF research group has expanded a previous study aiming at explaining how young secondary school students of Latin American and Chinese origin in Catalonia construct their linguistic and cultural identity. Here we analyze the relationship between these youngsters and their social environment in order to determine how these relationships and the socialization process that derives from them influence language attitudes and practices. We focus on two spaces of socialization: (1) the school, where youngsters from diverse cultural and linguistic backgrounds coexist and interact, and (2) the neighborhood, a geographic and symbolic space where social identity is constructed and, consequently, where young newcomers construct their perceptions regarding the host society, including its linguistic reality. We have collected several sets of data in three public secondary schools and three neighborhoods from Barcelona’s metropolitan area with a high index of immigrant population: (1) interviews with secondary school students, (2) interviews with teachers, (3) social discourses in newspapers that consolidate the social image of the neighborhood, (4) narratives from immigrant families in relation to their neighborhood, (5) participant observation in schools, and (5) observation in the neighborhood. The results of the thematic and, when appropriate, discursive analysis of the data allow us to reach conclusions regarding: (a) the social image of the neighborhoods, (b) the socialization of young newcomers in the schools and the neighborhoods, (c) the identity games, and (d) the language and cultural practices and attitudes of young people, in relation to their countries and languages of origin as well as the school and the neighborhood investigated.

Long run relationships and price rigidity

I study a repeated buyer-seller relationship for the exchange of a givengood. Asymmetric information over the buyer's reservation price, which issubject to random shocks, may lead the seller to use a rigid pricing policydespite the possibility of making higher profits through price discriminationacross the different satates of the buyer's reservation price. The existence of a flexible price subgame perfect equilibrium is shown for the buyerssufficiently locked-in. When the seller faces a population of buyers whose degree of involvmentin the relatioship is unknown, the flexible price equilibrium is notnecessarily optimal. Thus tipically the seller will prefer to use therigid price strategy. A learning process allowing the seller to screenthe population of buyers is derived abd the existence of a switching pointbetween the two regimes (i.e. price rigidity and price felxibility) isshown.

Subset correspondence analysis: Visualizing relationships among a selected set of response categories from a questionnaire survey

It is shown how correspondence analysis may be applied to a subset of response categories from a questionnaire survey, for example the subset of undecided responses or the subset of responses for a particular category. The idea is to maintain the original relative frequencies of the categories and not re-express them relative to totals within the subset, as would normally be done in a regular correspondence analysis of the subset. Furthermore, the masses and chi-square metric assigned to the data subset are the same as those in the correspondence analysis of the whole data set. This variant of the method, called Subset Correspondence Analysis, is illustrated on data from the ISSP survey on Family and Changing Gender Roles.

El Misterio de la biblioteca Mil.lènium o cómo promover relaciones colaborativas desde la participación del alumnado = The Mystery of the Mil.lènium Library: How to Promote Collaborative Relationships Through Student Participation

La pedagogía crítica acentúa la falta de neutralidad de la escuela respecto a las relaciones de poder que existen en la sociedad. Su propuesta consiste en modificar las relaciones de poder en el aula en el sentido de transformar las relaciones coercitivas –las que reproducen las relaciones existentes– en relaciones colaborativas partiendo del reconocimiento y la participación de los alumnos en las actividades escolares. Desde esta perspectiva, uno de los objetivos de las actividades es que los niños produzcan «textos identitarios», entendidos como artefactos que los alumnos se pueden apropiar para promover su desarrollo cognitivo. El artículo muestra el trabajo educativo integrado desde Educación Infantil hasta 6.º de Primaria de una escuela de la provincia de Girona en la que el 97% de los alumnos es de origen extranjero y cuyo propósito es incrementar las habilidades lingüísticas orales y escritas en la lengua escolar, así como la utilización de otros lenguajes multimedia. La unidad didáctica consiste en la elaboración de un cuento a lo largo de un curso escolar por parte de todo el alumnado con la ayuda de los profesores, de dos autores y de tres ilustradores. Cada ciclo escolar decide los personajes y el escenario y explicita textualmente el transcurso de la acción. Los ilustradores producen las imágenes y los autores posibilitan la transición de aquello que ha elaborado un ciclo al producto del siguiente. La actividad basada en la participación y la utilización de procedimientos democráticos de decisión se inserta en la propuesta educativa y lingüística de la escuela, así como en sus concreciones curriculares. Los resultados muestran que los textos construidos por los niños se apoyan en sus «fondos de conocimiento» sociales y familiares y constituyen una fuente de progreso en la consecución de las competencias básicas y en la construcción de valores democráticos

The extraordinarily bright optical afterglow of GRB 991208 and its host galaxy

Observations of the extraordinarily bright optical afterglow (OA) of GRB 991208 started 2.1 d after the event. The flux decay constant of the OA in the R-band is -2.30 +/- 0.07 up to 5 d, which is very likely due to the jet effect, and after that it is followed by a much steeper decay with constant -3.2 +/- 0.2, the fastest one ever seen in a GRB OA. A negative detection in several all-sky films taken simultaneously to the event implies either a previous additional break prior to 2 d after the occurrence of the GRB (as expected from the jet effect). The existence of a second break might indicate a steepening in the electron spectrum or the superposition of two events. Once the afterglow emission vanished, contribution of a bright underlying SN is found, but the light curve is not sufficiently well sampled to rule out a dust echo explanation. Our determination of z = 0.706 indicates that GRB 991208 is at 3.7 Gpc, implying an isotropic energy release of 1.15 x 10E53 erg which may be relaxed by beaming by a factor > 100. Precise astrometry indicates that the GRB coincides within 0.2' with the host galaxy, thus given support to a massive star origin. The absolute magnitude is M_B = -18.2, well below the knee of the galaxy luminosity function and we derive a star-forming rate of 11.5 +/- 7.1 Mo/yr. The quasi-simultaneous broad-band photometric spectral energy distribution of the afterglow is determined 3.5 day after the burst (Dec 12.0) implying a cooling frequency below the optical band, i.e. supporting a jet model with p = -2.30 as the index of the power-law electron distribution.