Biology and distribution of chafers (Coleoptera, Scarabaeidae) living in hollow trees in Sweden.

We review the ecology and distributions of the chafers Liocola marmorata (F.), Gnorimus nobilis (L.) and Gnorimus variabilis (L.) in Sweden based on museum and several large private collections. These species live in hollow deciduous trees, in Sweden especially in oaks. The former and recently documented localities are shown on maps. More than 100 years ago, all the species as well as their habitats were more common in Sweden than today. One problem when interpreting old finds is that hollow trees do not seem to have been examined by entomologists, except during the last 50 years. However, Gnorimus nobilis, which often visits flowers, was frequently found in former times. In the province of Skane, which has been most intensively studied among Swedish provinces, the number of known localities for Gnorimus nobilis has decreased from 13 before 1975 to 6 after that year, despite more intensive studies during the last 25 years. Of the studied species, Liocola marmorata has had the largest contraction of its range in Sweden. It has disappeared from the southwestern part, but occurs still in many localities in the provinces of Ostergotland and Uppland. In Uppland, the absence of Osmoderma eremita, which has a similar niche, may decrease the competition in tree hollows and favour L. marmorata. Gnorimus varibilis has a preference for sun-exposed oaks, and can live in downed dead trees long after the trunk has fallen. It has been found at about 30 localities in Sweden during the last 25 years. We suggest that Gnorimus variabilis is a globally threatened species and that Sweden has a strong responsibility to preserve this species. There are still seven localities in southeastern Sweden where all three species as well as Osmoderma eremita occur. All these localities harbour a high number of threatened saproxylic beetles. We discuss the chafers living in hollow trees as indicator species and propose conservation measures for them. The highest priority should be given to increase the survival rate and number of very old trees, especially oaks, in and near stands which inhabit the species and contains a large number of suitable hollow trees

Occurrence of the hermit beetle (Osmoderma eremita), in Sweden.

We have compiled data on the occurrence of a threatened beetle, Osmoderma eremita, in Sweden. The species inhabits tree hollows with wood mould. The data were compiled from field surveys conducted in 1993-2003, using pitfall traps at 401 localities and using wood mould sampling at 104 localities. We have also gone through published data and all larger Swedish museums and registered old records. O. eremita was recorded at about 30% of the field surveys. In Sweden, oak is by far the most important host tree species, but the beetle has also been found in other deciduous trees, such as beech, alder, ash and lime. Currently, 270 localities with Osmoderma eremita, defined as records of living adults, larvae, fragments of adult body parts, or excrements situated at least 1 km from each other, are known in Sweden. 129 of these localities are records of live beetles or larvae made after 1990. The species is found in the southern third of Sweden only, and there are more localities in the eastern part compared to the western. The great majority of the localities have been discovered during the last ten years. At some of the localities only excrements or fragments have been recorded, and the species might actually be extinct at some of these localities. Due to low search intensity historically, it is impossible to use these data to discover any changes in the distribution or occurrence over time. Because old, hollow oaks were much more frequent 200 years ago, we suggest that the species has decreased severely in Sweden since that time. Today, old oaks are rarely cut down but instead lack of grazing cattle is a threat because many sites regrow with dense tree stands which outcompete the old hollow trees. Many local extinctions could also be expected during the next few decades, because many of the localities have too few hollow trees and are too isolated. At many localities, lack of younger trees which can take over the role as host trees when the present trees die will also be a problem in the future

The gut microbiota and developmental programming of the testis in mice

Nutrients and environmental chemicals, including endocrine disruptors, have been incriminated in the current increase in male reproductive dysfunction, but the underlying mechanisms remain unknown. The gastrointestinal tract represents the largest surface area exposed to our environment and thereby plays a key role in connection with exposure of internal organs to exogenous factors. In this context the gut microbiome (all bacteria and their metabolites) have been shown to be important contributors to body physiology including metabolism, cognitive functions and immunity. Pivotal to male reproduction is a proper development of the testis, including the formation of the blood-testis barrier (BTB) that encapsulates and protects germ cells from stress induced environmental cues, e.g. pathogenic organisms and xenobiotics. Here we used specific pathogen free (SPF) mice and germ-free (GF) mice to explore whether gut microbiota and/or their metabolites can influence testis development and regulation of BTB. Lumen formation in the seminiferous tubules, which coincides with the development of the BTB was delayed in the testes of GF mice at 16 days postpartum. In addition, perfusion experiments (Evans blue) demonstrated increased BTB permeability in these same mice. Reduced expressions of occludin, ZO-2 and E-cadherin in GF testis suggested that the microbiota modulated BTB permeability by regulation of cell-cell adhesion. Interestingly, exposure of GF mice to Clostridium Tyrobutyricum (CBUT), which secrete high levels of butyrate, restored the integrity of the BTB and normalized the levels of cell adhesion proteins. Moreover, the GF mice exhibited lower serum levels of gonadotropins (LH and FSH) than the SPF group. In addition, the intratesticular content of testosterone was lower in GF compared to SPF or CBUT animals. Thus, the gut microbiome can modulate the permeability of the BTB and might play a role in the regulation of endocrine functions of the testis.Scopu

Tissue-specific transcriptional imprinting and heterogeneity in human innate lymphoid cells revealed by full-length single-cell RNA-sequencing

The impact of the microenvironment on innate lymphoid cell (ILC)-mediated immunity in humans remains largely unknown. Here we used full-length Smart-seq2 single-cell RNA-sequencing to unravel tissue-specific transcriptional profiles and heterogeneity of CD127+ ILCs across four human tissues. Correlation analysis identified gene modules characterizing the migratory properties of tonsil and blood ILCs, and signatures of tissue-residency, activation and modified metabolism in colon and lung ILCs. Trajectory analysis revealed potential differentiation pathways from circulating and tissue-resident na\uefve ILCs to a spectrum of mature ILC subsets. In the lung we identified both CRTH2+ and CRTH2− ILC2 with lung-specific signatures, which could be recapitulated by alarmin-exposure of circulating ILC2. Finally, we describe unique TCR-V(D)J-rearrangement patterns of blood ILC1-like cells, revealing a subset of potentially immature ILCs with TCR-δ rearrangement. Our study provides a useful resource for in-depth understanding of ILC-mediated immunity in humans, with implications for disease

Reading Across Cultures: Global Narratives, Hotels and Railway Stations

This is the final version of the article. Available from Springer Verlag via the DOI in this record.This article takes its cue from the English critic, novelist and painter John Berger. He argues that what we know determines what we see. Hotels and railway stations, though they differ in size, design and appearance, are places of temporary national and international congress that are recognized by everyone. They become visible or even iconic once their history or their role is turned into at least part of a wider narrative—in literature, film or in other arts. This provides a representative focus by which we may read a city’s or a nation’s past. In exemplifying such connections I focus first on the long-term history of Friedrichstraße station and some of the surrounding hotels in the context of the history of Berlin, situating them within the national and, by implication, also the international context. Secondly, I will consider the outbreak of the First World War in 1914 as an event in which the role of railway stations generated both personal and collective memories across cultures and over several decades

Restricted dispersal in a flying beetle assessed by telemetry

Many insects living in ancient trees are assumed to be threatened as a result of habitat loss and fragmentation. It is generally expected that species in habitats with low temporal variability in carrying capacity have lower degree of dispersal in comparison to those in more ephemeral habitats. As hollow trees are long-lived, species in that habitat are expected to be sensitive to habitat fragmentation, due to a low capacity to establish new populations far from present ones. Using radio telemetry, we studied the dispersal for a beetle, Osmoderma eremita, living in hollow trees. O. eremita exhibited philopatry and only dispersed over short ranges. 82-88 % of the adults remained in the tree where they were caught. All observed dispersal movements ended up in nearby hollow trees and 62 % in the neighbouring hollow tree. These results corroborate the suggestion that habitat fragmentation may be detrimental to insects living in temporally stable but spatially variable habitats. In order to preserve such species, we propose that conservation efforts should be focused on maintaining or increasing the number of suitable trees in and near presently occupied stands