53 research outputs found

    Species-level divergences in multiple functional traits between the two endemic subspecies of Blue Chaffinches Fringilla teydea in Canary Islands

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    Background: One of the biggest challenges in avian taxonomy is the delimitation of allopatric species because their reproductive incompatibility cannot be directly studied in the wild. Instead, reproductive incompatibility has to be inferred from multiple, divergent character sets that indicate a low likelihood of allopatric populations amalgamating upon secondary contact. A set of quantitative criteria for species delimitation has been developed for avian taxonomy. Results: Here, we report a broad multi-trait comparison of the two insular subspecies of the Blue Chaffinch Fringilla teydea, endemic to the pine forests of Tenerife (ssp. teydea) and Gran Canaria (ssp. polatzeki) in the Canary Islands. We found that the two taxa were reciprocally monophyletic in their whole mitogenomes and two Z chromosome introns. The genetic distance in mitogenomes indicates around 1 Mya of allopatric evolution. There were diagnostic differences in body morphometrics, song and plumage reflectance spectra, whose combined divergence score (=11) exceeds the threshold level (=7) set for species delimitation by Tobias et al. (Ibis 152:724–746, 2010). Moreover, we found a marked divergence in sperm lengths with little range overlap. Relatively long sperm with low intra- and intermale CV compared to other passerines suggest a mating system with high levels of sperm competition (extrapair paternity) in these taxa. Conclusion: The large and diagnostic divergences in multiple functional traits qualify for species rank, i.e., Tenerife Blue Chaffinch (Fringilla teydea) and Gran Canaria Blue Chaffinch (Fringilla polatzeki). We encourage a wider use of sperm traits in avian taxonomy because sperm divergences might signal reproductive incompatibility at the postcopulatory prezygotic stage, especially in species with sperm competition

    W(h)ither the academy? An exploration of the role of university social work in shaping the future of social work in Europe

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    A controversial proposal to pilot the training of child protection social workers through an intensive work-based route in England is being supported and funded by the UK Government. Frontline, the brainchild of a former teacher, locates social work training within local authorities (‘the agency’) rather than university social work departments (‘the academy’) and has stimulated debate amongst social work academics about their role in shaping the direction of the profession. As a contribution to this debate, this paper explores the duality of social work education, which derives its knowledge from both the academic social sciences and the experience of practice within social work agencies. While social work education has traditionally been delivered by the academy, this paper also explores whether the delivery of training in the allied professions of probation and nursing by ‘the agency’ is equally effective. Finally, this paper explores the Helsinki model which achieves a synergy of ‘academy’ and ‘agency’. It suggests that there are alternative models of social work education, practice and research which avoid dichotomies between the ‘academy’ and the ‘agency’ and enable the profession to be shaped by both social work academics and practitioners

    Modulation of epithelial sodium channel (ENaC) expression in mouse lung infected with Pseudomonas aeruginosa

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    BACKGROUND: The intratracheal instillation of Pseudomonas aeruginosa entrapped in agar beads in the mouse lung leads to chronic lung infection in susceptible mouse strains. As the infection generates a strong inflammatory response with some lung edema, we tested if it could modulate the expression of genes involved in lung liquid clearance, such as the α, β and γ subunits of the epithelial sodium channel (ENaC) and the catalytic subunit of Na(+)-K(+)-ATPase. METHODS: Pseudomonas aeruginosa entrapped in agar beads were instilled in the lung of resistant (BalB/c) and susceptible (DBA/2, C57BL/6 and A/J) mouse strains. The mRNA expression of ENaC and Na(+)-K(+)-ATPase subunits was tested in the lung by Northern blot following a 3 hours to 14 days infection. RESULTS: The infection of the different mouse strains evoked regulation of α and β ENaC mRNA. Following Pseudomonas instillation, the expression of αENaC mRNA decreased to a median of 43% on days 3 and 7 after infection and was still decreased to a median of 45% 14 days after infection (p < 0.05). The relative expression of βENaC mRNA was transiently increased to a median of 241%, 24 h post-infection before decreasing to a median of 43% and 54% of control on days 3 and 7 post-infection (p < 0.05). No significant modulation of γENaC mRNA was detected although the general pattern of expression of the subunit was similar to α and β subunits. No modulation of α(1)Na(+)-K(+)-ATPase mRNA, the catalytic subunit of the sodium pump, was recorded. The distinctive expression profiles of the three subunits were not different, between the susceptible and resistant mouse strains. CONCLUSIONS: These results show that Pseudomonas infection, by modulating ENaC subunit expression, could influence edema formation and clearance in infected lungs

    The Long Term Response of Birds to Climate Change: New Results from a Cold Stage Avifauna in Northern England

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    The early MIS 3 (55–40 Kyr BP associated with Middle Palaeolithic archaeology) bird remains from Pin Hole, Creswell Crags, Derbyshire, England are analysed in the context of the new dating of the site’s stratigraphy. The analysis is restricted to the material from the early MIS 3 level of the cave because the upper fauna is now known to include Holocene material as well as that from the Late Glacial. The results of the analysis confirm the presence of the taxa, possibly unexpected for a Late Pleistocene glacial deposit including records such as Alpine swift, demoiselle crane and long-legged buzzard with southern and/or eastern distributions today. These taxa are accompanied by more expected ones such as willow ptarmigan /red grouse and rock ptarmigan living today in northern and montane areas. Finally, there are temperate taxa normally requiring trees for nesting such as wood pigeon and grey heron. Therefore, the result of the analysis is that the avifauna of early MIS 3 in England included taxa whose ranges today do not overlap making it a non-analogue community similar to the many steppe-tundra mammalian faunas of the time. The inclusion of more temperate and woodland taxa is discussed in the light that parts of northern Europe may have acted as cryptic northern refugia for some such taxa during the last glacial. These records showing former ranges of taxa are considered in the light of modern phylogeographic studies as these often assume former ranges without considering the fossil record of those taxa. In addition to the anomalous combination of taxa during MIS 3 living in Derbyshire, the individuals of a number of the taxa are different in size and shape to members of the species today probably due to the high carrying capacity of the steppe-tundra

    Percolation Transition in Hole-Conducting Acceptor-Doped Barium Zirconate

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    Acceptor-doped perovskite oxides are highly attractive materials for renewable energy applications such as protonic ceramic fuel cells. Cathode materials with mixed protonic and electronic conductivity are then highly desirable. Here, we consider acceptor-doped BaZrO3 as a potential mixed conductor using the density functional theory. We study the effect of the dopant atom on the formation of electronic hole polarons and establish that doping of BaZrO3 with Fe and Y, respectively, leads to completely different polaron configurations, in which the polaron is centered on the dopant when BaZrO3 is Fe-doped and on an oxygen ion when BaZrO3 is Y-doped. These differences are attributed to the difference in covalency between Fe-O and Y-O bonds, with the former having a much more covalent character. The stronger covalency also results in a stronger association of the polaron with Fe than Y. With a large Fe concentration of 25%, the acceptor state is significantly smeared in energy with a near closing of the electronic band gap. At this concentration level, Fe-doped BaZrO3 is thus on the verge of becoming metallic along the Fe-clusters, supporting the experimental finding of percolation conductivity in Fe-doped BaZrO3 [Kim et al., Solid State Ionics 2014, 262, 875]. In contrast, the effect of increased dopant concentration on the electronic structure in Y-doped BaZrO3 is only minor. Our results provide new atomistic insights into hole transport in acceptor-doped BaZrO3 and highlight the importance of the chemical nature of the dopant atom on the material\u27s electronic properties

    Intestinal spirochetosis in eight pediatric patients from Southern Sweden - A clinical, histopathological and ultrastructural study

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    Intestinal spirochetes in humans have been recognized for more than a century, but it is still a matter of debate whether they are just commensal organisms or whether they cause colorectal disease. Most descriptions to date are of adult patients, while reports in the pediatric literature have been scarce. In a retrospective study we found eight children with intestinal spirochetosis. The findings, clinical as well as pathological, with light- and electron microscopy, are presented. In all patients, a 3 pm-thick layer of spirochetes was visualised on the luminal aspect of the epithelial cells covering the enterocytes and part of the gland openings. In five of the eight cases an inflammatory cell reaction was seen by light microscopy and in one patient a picture suggesting intracytoplasmatically located spirochetes was seen by electron microscopy. Despite partial or complete destruction of microvilli, spirochetes were still able to adhere to the enterocyte membranes. In three children there was a clear correlation between treatment and relief of symptoms. In four there was partial improvement and in one child no change in bowel-related symptoms. We believe that intestinal spirochetes may cause colorectal disease in children. Possible pathogenic mechanisms are discussed
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