Oviposition, life cycle, and parasitoids of the spruce cone maggot, Strobilomyia anthracina (Diptera: Anthomyiidae), in the Alps

The life cycle of Strobilomyia anthracina (Czerny) which exploits Norway spruce seed cones was investigated in 1992 and 1993 in the Alps at c. 1800 m at Torgnon (Valle d'Aosta, Italy) and Lac de Tseuzier (Valais, Switzerland) by sampling cones at fortnightly intervals. Oviposition occurred primarily singly in the basal third of cones at the beginning of June when cone scales were open for pollination. Infestation rates were higher when cone crops were poor. Most larvae left the cones in August to pupate in the litter beneath trees, usually at a depth of 1-4 cm. Prolonged diapause of pupae coincided with failed or poor cone crops. Parasitism was investigated at these two and 27 additional sites in the Swiss, French and Italian Alps. Among several hundred host eggs only one was parasitized by Trichogramma sp. (Trichogrammatidae). Among the larval-pupal endoparasitoids, the figitid Sarothrus areolatus Hartig was more common than an ichneumonid, Atractodes sp., but parasitism by both was commonly below 10%. Parasitism by an ichneumonid larval ectoparasitoid, Scambus sp., also rarely exceeded 10%. Puparia of S. anthracina that were buried in the litter to detect pupal parasitoids revealed the gregarious pteromalid Tritneptis sp. near lophyrorum (Rushka). This is the first record of a pupal parasitoid of Strobilomyia species. Information on the biology of the three larval parasitoids is presented. The potential for biological control of North American Strobilomyia neanthracina Michelsen and S. appalachensis Michelsen by importation of natural enemies of S. anthracina appears limite

The nonlinear directional coupler. An analytic solution

Linear and nonlinear directional couplers are currently used in fiber optics communications. They may also play a role in multiphoton approaches to quantum information processing if accurate control is obtained over the phases and polarizations of the signals at the output of the coupler. With this motivation, the constants of motion of the coupler equation are used to obtain an explicit analytical solution for the nonlinear coupler.Comment: 6 pages Late

La explicación a través de la visualización de redes

Las evaluaciones de causa y efecto, configuraciones y dinámicas están en el corazón de nuestro pensamiento y nuestras explicaciones (Tufte 1997: 9). Aunque se han desarrollado muchos métodos para dichas evaluaciones, que son utilizados en nuestra práctica científica diaria, es frecuente que la visualización no sea considerada uno de ellos. En este artículo, defendemos en primer lugar que ésto se debe a la práctica habitual de visualizar los datos en lugar de la información contenida en los mismos. En segundo lugar, repasamos una serie de principios para la visualización efectiva. Tercero, valoramos algunos ejemplos específicos de la visualización de redes basada en estos principios. Cuarto, demostramos que la visualización de información aplicada a redes no sólo es un posible método para el análisis de configuraciones, dinámicas y causas, sino que, además, tiene un valor añadido en comparación con otros métodos. Finalmente, concluimos con algunas implicaciones para la visualización de redes sociales.Assessments of configurations, dynamics, and cause and effect are at the heart of our thinking and explanation. Although numerous methods for such assessments have been developed and are being used in our daily scientific practice, visualization is frequently not considered one of them. In this paper we will first argue that this is due to the common practice of visualizing data rather than the information contained in it; secondly, we address a number of principles for effective visualization; thirdly, we assess specific examples for the visualization of networks on these principles; fourthly, we demonstrate that information visualization applied to networks is not only a possible method to analyze configurations, dynamics, and cause but, moreover, that it has an added value compared to other methods. We conclude with implications for the visualization of social networks

Comparative developmental biology of populations of three European and one North American Eubazus spp. (Hymenoptera: Braconidae), parasitoids of Pissodes spp. weevils (Coleoptera: Curculionidae)

Observations were made on the developmental responses of the North American braconid species, Eubazus crassigaster, a parasitoid of the white pine weevil, Pissoles strobi, and three European congeneric species, E. semirugosus, E. robustus, and Eubazus sp. Several populations of Eubazus spp. were compared in their phenology in the laboratory and under natural conditions. When reared in the laboratory on non-diapausing Pissodes castaneus, mountain populations of E. semirugosus and E. robustus entered into an obligatory diapause in the host larva, whereas all the other populations tested developed continuously. Diapausing larvae continued their development only after having experienced at least three months at 2°C. Non-diapausing populations of Eubazus spp. significantly differed in the duration of pre-imaginal development, with E. semirugosus being the fastest developing species and E. robustus the slowest. Outdoor rearings of Eubazus spp. on P. castaneus showed that E. crassigaster, Eubazus sp. and the lowland biotype of E. semirugosus emerged in the year of oviposition if this occurred early enough to allow parasitoid development. In contrast, a majority of E. robustus individuals overwintered in the host larvae, regardless of the oviposition date. The diapausing, mountain biotype of E. semirugosus is considered as the most promising candidate for control of P. strobi in Canada, because it is likely to be better adapted to the life cycle of the target host than the other Eubazus spp., including the native E. crassigaste

Evidence for the occurrence of sibling species in Eubazus spp. (Hymenoptera: Braconidae), parasitoids of Pissodes spp. weevils (Coleoptera: Curculionidae)

Comparative studies were made on three presumed sibling species of the genus Eubazus, parasitoids of European Pissodes spp. weevils, to clarify their taxonomy and define diagnostic characters. Several populations of E. semirugosus (Nees), E. robustus (Ratzeburg) and Eubazus sp. were compared with respect to their morphology (mainly through morphometric analyses), fecundity, isoenzyme patterns and host preference. Crosses were made to assess the genetic and behavioural compatibility of the populations. In addition, the North American E. crassigaster (Provancher), a parasitoid of Pissodes strobi (Peck), was compared to E. semirugosus, a species selected for introduction against P. strobi in Canada. The ratio of the length of the ovipositor sheath to the fore wing length was the most discriminating morphometric variable, but discriminant analyses including several measurements were needed to completely separate European species. A canonical discriminant function provided a total separation between males of E. crassigaster and E. semirugosus, but not between females. Eubazus crassigaster and E. semirugosus were totally separated by the banding pattern of the enzyme phosphogluconate dehydrogenase whereas hexokinase and esterase provided a diagnostic separation between Eubazus sp. and E. robustus. Eubazus sp. differed from all the other species by having a greater number of ovarioles and, consequently, a higher potential fecundity. In a two-choice oviposition test, E. semirugosus and Eubazus sp. showed a significant preference for their natural host, P. castaneus De Geer and P. piceae (Illiger), respectively. A similar test made with their progenies reared under standard conditions showed that the difference in host preference was genetically fixed. Males and females of different species did not mate readily, in contrast to individuals from the same species. All attempts to interbreed E. robustus and Eubazus sp. failed, but a few crosses between E. semirugosus and the two other European species produced fertile offspring. These observations strongly suggest that the complex of Eubazus spp. parasitoids attacking Pissodes spp. in Europe is composed of at least three sibling species, two of which appear to have specialized on distinct host species that occupy exclusive microhabitat

Neuroinflammation and Its Resolution: From Molecular Mechanisms to Therapeutic Perspectives

Neuroinflammation, the complex immune response of the central nervous system (CNS), when sustained, is a common denominator in the etiology and course of all major neurological diseases, including neurodevelopmental, neurodegenerative, and psychiatric disorders (e.g., Alzheimer's disease, AD; Parkinson's disease, PD; multiple sclerosis, MS; motor neuron disease; depression; autism spectrum disorder; and schizophrenia). Cellular (microglia and mast cells, two brain-resident immune cells, together with astrocytes) and molecular immune components (e.g., cytokines, complement and patternrecognition receptors) act as key regulators of neuroinflammation (Skaper et al., 2012). In response to pathological triggers or neuronal damage, immune cells start an innate immune response with the aim to eliminate the initial cause of injury. However, when the cellular activity becomes dysregulated, it results in an inappropriate immune response that can be injurious and affect CNS functions. Thus, limiting neuroinflammation and microglia activity represents a potential strategy to alleviate neuroinflammationrelated diseases. The Research Topic collects 20 manuscripts, divided into five sections, that include both original research articles and reviews of the emerging literature and explore the role of neuroinflammation in various neurological diseases. There is particular attention dedicated to the relevant research exploring the mechanisms and mediators involved in the resolution of neuroinflammation. Our aim was to generate a valuable discussion contributing to identify new therapeutic targets in brain damage and providing new drug development opportunities for the prevention and treatment of CNS diseases involving neuroinflammation

A study of the parasitoid complex of the European fir budworm, Choristoneura murinana (Lepidoptera: Tortricidae), and its relevance for biological control of related hosts

The parasitoid complex and apparent parasitism of Choristoneura murinana Hübner were investigated in relation to the relative abundance of budworm larvae at several sites in Europe. A single outbreak population was sampled, while other sites supported varying but much lower host population abundance. Sampling at Sion in Switzerland from 1984-89, indicated that the species richness of the parasitoid complex was correlated with relative host abundance and in general more polyphagous parasitoids were represented in sites with greater budworm abundance. Of the specialized parasitoids, Apanteles murinanae Čapek & Zwölfer (Hymenoptera: Braconidae) was dominant in less abundant host populations and both Cephaloglypta murinanae (Bauer) and Dirophanes maculicornis (Stephens) (Hymenoptera: Ichneumonidae) were supported only at greater budworm abundance. These findings are discussed in relation to the use of Choristoneura murinana parasitoids in the biological control of native Choristoneura spp. pests in other continent

La explicación a través de la visualización de redes

Assessments of configurations, dynamics, and cause and effect are at the heart of our thinking and explanation. Although numerous methods for such assessments have been developed and are being used in our daily scientific practice, visualization is frequently not considered one of them. In this paper we will first argue that this is due to the common practice of visualizing data rather than the information contained in it; secondly, we address a number of principles for effective visualization; thirdly, we assess specific examples for the visualization of networks on these principles; fourthly, we demonstrate that information visualization applied to networks is not only a possible method to analyze configurations, dynamics, and cause but, moreover, that it has an added value compared to other methods. We conclude with implications for the visualization of social networks.Las evaluaciones de causa y efecto, configuraciones y dinámicas están en el corazón de nuestro pensamiento y nuestras explicaciones (Tufte 1997: 9). Aunque se han desarrollado muchos métodos para dichas evaluaciones, que son utilizados en nuestra práctica científica diaria, es frecuente que la visualización no sea considerada uno de ellos. En este artículo, defendemos en primer lugar que ésto se debe a la práctica habitual de visualizar los datos en lugar de la información contenida en los mismos. En segundo lugar, repasamos una serie de principios para la visualización efectiva. Tercero, valoramos algunos ejemplos específicos de la visualización de redes basada en estos principios. Cuarto, demostramos que la visualización de información aplicada a redes no sólo es un posible método para el análisis de configuraciones, dinámicas y causas, sino que, además, tiene un valor añadido en comparación con otros métodos. Finalmente, concluimos con algunas implicaciones para la visualización de redes sociales