1,344 research outputs found
Geos 1 observations at Malvern, England
Satellite observation techniques and data processing methods at optical tracking station in Malvern, Englan
Immune function and parasite resistance in male and polymorphic female Coenagrion puella
Background:
Colour polymorphisms are widespread and one of the prime examples is the colour
polymorphism in female coenagrionid damselflies: one female morph resembles the male colour
(andromorph) while one, or more, female morphs are described as typically female (gynomorph).
However, the selective pressures leading to the evolution and maintenance of this polymorphism
are not clear. Here, based on the hypothesis that coloration and especially black patterning can be
related to resistance against pathogens, we investigated the differences in immune function and
parasite resistance between the different female morphs and males.
Results:
Our studies of immune function revealed no differences in immune function between the
female morphs but between the sexes in adult damselflies. In an experimental infection females
infected shortly after emergence showed a higher resistance against a fungal pathogen than males,
however female morphs did not differ in resistance. In a field sample of adult damselflies we did not
find differences in infection rates with watermites and gregarines.
Conclusion:
With respect to resistance and immune function 'andromorph' blue females of
Coenagrion puella do not resemble the males. Therefore the colour polymorphism in coenagrionid
damselflies is unlikely to be maintained by differences in immunity
Phenology determines seasonal variation in ectoparasite loads in a natural insect population
1. The extent to which individuals are parasitised is a function of exposure to parasites and the immune response, which in ectotherms may be associated with temperature. 2. We test the hypothesis that seasonal variation in ectoparasite burden is driven by temperature using an extensive mark-release-recapture study of adult Coenagrion puella (L.) (Zygoptera) as a model system. Mite counts were taken both at capture and on a subset of subsequent recaptures over two entire, consecutive breeding seasons. 3. Emergence date was the most significant factor in determining individual differences in mite burden, and mean counts for individuals emerging on the same days showed strong unimodal relationships with time of season. Subsequent recounting of mites on a subset of individuals showed that patterns of loss of mites were similar between seasons. 4. While temperature did not significantly affect mite burdens within seasons and ectoparasite prevalence was very similar across the two seasons, intensity of infection and rate of mite gain in unparasitised individuals were significantly higher in the cooler season. 5. We demonstrate that, while temperature may modulate the invertebrate immune response, this modulation does not manifest in variations in mite burdens in natural populations
Wiedernutzung von Industriebrachen für eine ökologisch, sozial und wirtschaftlich nachhaltige Stadtentwicklung? Einschätzungen und Bewertungen zum Projekt CultNature
Dargestellt werden die Ergebnisse einer Befragung zu den ersten Einschätzungen des CultNature-Konzepts durch die für das Projekt relevanten Akteure. Ziel ist die Abschätzung des mit dem Projekt verbundenen Erwartungshorizontes. Das Projekt wurde von den relevanten Akteuren in vielen Punkten positiv beurteilt. Man kann also davon ausgehen, dass CultNature im Ruhrgebiet und den anderen Bergbaurückzugsgebieten bei den befragten Akteuren insgesamt auf Akzeptanz stößt. Die meisten Befragten gehen davon aus, dass das Flächenpotenzial für CultNature in den Bergbaurückzugsgebieten vorhanden ist. Trotz der positiven Bewertung von CultNature sind viele der Befragten der Ansicht, dass die Realisierung von CultNature mit Interessenkonflikten und Auseinandersetzungen verbunden sein kann. Die Ergebnisse zu den Aussagen über die Erfolgsbedingungen bestätigen klar, wie notwendig eine integrierte Stadtentwicklung ist
Testing for knowledge : maximising information obtained from fire tests by using machine learning techniques
A machine learning (ML) algorithm was applied to predict the onset of flashover in 1:5 scale Room Corner Test experiments with sandwich panels. Towards this end, a penalized logistic regression model was chosen to detect the relevant variables and consequently provided a tool that can be used to make predictions of unseen samples. The method indicates that a deeper understanding of the contributing factors leading to flashover can be achieved. Furthermore, it allows a more nuanced ranking than currently offered by the commonly used classification methods for reaction to fire tests. The proposed methodology shows a substantial value in terms of guidance for future large and intermediate scale testing. In particular, it is foreseen that the method will be extremely useful for assessing and understanding the behaviour of innovative materials and design solutions
Intraspecific predation in immature Coenagrion puella (L.): a switch in food selection? (Zygoptera: Coenagrionidae)
Observations on cannibalism in outdoor insectaries are presented. The behavioural interactions are described. Cannibalism (in both sexes) occurred only during periods of cold weather. It is hypothesised that intraspecific predation is a switch in food selection due to bad weather conditions
Exposure of Larvae of the Solitary Bee Osmia bicornis to the Honey Bee Pathogen Nosema ceranae Affects Life History
Wild bees are important pollinators of wild plants and agricultural crops and they are threatened by several environmental stressors including emerging pathogens. Honey bees have been suggested as a potential source of pathogen spillover. One prevalent pathogen that has recently emerged as a honey bee disease is the microsporidian Nosema ceranae. While the impacts of N. ceranae in honey bees are well documented, virtually nothing is known about its effects in solitary wild bees. The solitary mason bee Osmia bicornis is a common pollinator in orchards and amenable to commercial management. Here, we experimentally exposed larvae of O. bicornis to food contaminated with N. ceranae and document spore presence during larval development. We measured mortality, growth parameters, and timing of pupation in a semi-field experiment. Hatched individuals were assessed for physiological state including fat body mass, wing muscle mass, and body size. We recorded higher mortality in the viable-spore-exposed group but could only detect a low number of spores among the individuals of this treatment. Viable-spore-treated individuals with higher head capsule width had a delayed pupation start. No impact on the physiological status could be detected in hatched imagines. Although we did not find overt evidence of O. bicornis infection, our findings indicate that exposure of larvae to viable N. ceranae spores could affect bee development
Nachwuchsprobleme im Handwerk: Eine Studie im nördlichen Ruhrgebiet
Dem Handwerk im nördlichen Ruhrgebiet geht der qualifizierte Nachwuchs verloren. Rund 35% aller Betriebe melden bereits Probleme bei der Findung geeigneter Bewerberinnen und Bewerber mit Hauptschulabschluss. Bei Bewerberinnen und Bewerbern mit Realschulabschluss oder Abitur wird es schon für 52% der Betriebe schwierig. Sogar die Handwerksbereiche, die als besonders attraktiv gelten, wie das Metall- und Elektrogewerbe, haben Probleme bei der Rekrutierung
Jugendliche im Handwerk: Erfahrungen vor und während der Ausbildung
Die Ausbildung im Handwerk wird von den dort tätigen Azubis deutlich positiv beurteilt. 88,1% der Auszubildenden würden anderen Jugendlichen eine Ausbildung im Handwerk empfehlen. Das bei Außenstehenden eher schlechte Bild vom Handwerk deutet auf ein Imageproblem hin. Offenbar fehlen Informationen über Chancen und Karrieremöglichkeiten einer Ausbildung im Handwerk. Auszubildende im Handwerk informieren sich bei den Ausbildungsbetrieben, weniger in Schule und Arbeitsagentur. 78,4% der Jugendlichen entschieden sich aufgrund persönlichen Interesses für eine Ausbildung im Handwerk. Die Auszubildenden sind im Durchschnitt mit ihrer Ausbildung zufrieden. Das Qualitätsproblem der Ausbildungsbetriebe spielt für die Jugendlichen kaum eine Rolle: Nach Selbsteinschätzung der Auszubildenden werden außer im Bereich der Fremdsprachen und Mathematik keine nennenswerten Defizite gesehen
Inducible Defenses Stay Up Late: Temporal Patterns of Immune Gene Expression in Tenebrio molitor
The course of microbial infection in insects is shaped by a two-stage process of immune defense. Constitutive defenses, such as engulfment and melanization, act immediately and are followed by inducible defenses, archetypically the production of antimicrobial peptides, which eliminate or suppress the remaining microbes. By applying RNAseq across a 7-day time course, we sought to characterize the long-lasting immune response to bacterial challenge in the mealworm beetle Tenebrio molitor, a model for the biochemistry of insect immunity and persistent bacterial infection. By annotating a hybrid de novo assembly of RNAseq data, we were able to identify putative orthologs for the majority of components of the conserved insect immune system. Compared with Tribolium castaneum, the most closely related species with a reference genome sequence and a manually curated immune system annotation, the T. molitor immune gene count was lower, with lineage-specific expansions of genes encoding serine proteases and their countervailing inhibitors accounting for the majority of the deficit. Quantitative mapping of RNAseq reads to the reference assembly showed that expression of genes with predicted functions in cellular immunity, wound healing, melanization, and the production of reactive oxygen species was transiently induced immediately after immune challenge. In contrast, expression of genes encoding antimicrobial peptides or components of the Toll signaling pathway and iron sequestration response remained elevated for at least 7 days. Numerous genes involved in metabolism and nutrient storage were repressed, indicating a possible cost of immune induction. Strikingly, the expression of almost all antibacterial peptides followed the same pattern of long-lasting induction, regardless of their spectra of activity, signaling possible interactive roles in vivo
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