Bat and bird diversity along independent gradients of latitude and tree composition in European forests

Species assemblages are shaped by local and continental-scale processes that are seldom investigated together, due to the lack of surveys along independent gradients of latitude and habitat types. Our study investigated changes in the effects of forest composition and structure on bat and bird diversity across Europe. We compared the taxonomic and functional diversity of bat and bird assemblages in 209 mature forest plots spread along gradients of forest composition and vertical structure, replicated in 6 regions spanning from the Mediterranean to the boreal biomes. Species richness and functional evenness of both bat and bird communities were affected by the interactions between latitude and forest composition and structure. Bat and bird species richness increased with broadleaved tree cover in temperate and especially in boreal regions but not in the Mediterranean where they increased with conifer abundance. Bat species richness was lower in forests with smaller trees and denser understorey only in northern regions. Bird species richness was not affected by forest structure. Bird functional evenness increased in younger and denser forests. Bat functional evenness was also influenced by interactions between latitude and understorey structure, increasing in temperate forests but decreasing in the Mediterranean. Covariation between bat and bird abundances also shifted across Europe, from negative in southern forests to positive in northern forests. Our results suggest that community assembly processes in bats and birds of European forests are predominantly driven by abundance and accessibility of feeding resources, i.e., insect prey, and their changes across both forest types and latitudes.     

Method for Isolation of Bacteroides Bacteriophage Host Strains Suitable for Tracking Sources of Fecal Pollution in Water

Bacteriophages infecting Bacteroides are potentially a good tool for fecal source tracking, but different Bacteroides host strains are needed for different geographic areas. A feasible method for isolating Bacteroides host strains for phages present in human fecal material is described. Useful strains were identified for application in Spain and the United Kingdom. One strain, GA-17, identified as Bacteroides thetaiotaomicron, was tested in several locations in Europe with excellent performance in Southern Europe.     

Biochemical and spectroscopic studies of human melanotransferrin (MTf): electron-paramagnetic resonance evidence for a difference between the iron-binding site of MTf and other transferrins

Melanotransferrin (MTf) is a member of the transferrin (Tf) family of iron (Fe)-binding proteins that was first identified as a cell-surface marker of melanoma. Although MTf has a high-affinity Fe-binding site that is practically identical to that of serum Tf, the protein does not play an essential role in Fe homeostasis and its precise molecular function remains unclear. A Zn(II)-binding motif, distinct from the Fe-binding site, has been proposed in human MTf based on computer modelling studies. However, little is known concerning the interaction of its proposed binding site(s) with metals and the consequences in terms of MTf conformation. For the first time, biochemical and spectroscopic techniques have been used in this study to characterise metal ion-binding to recombinant MTf. Initially, the binding of Fe to MTf was examined using 6M urea gel electrophoresis. Although four different iron-loaded forms were observed with serum Tf, only two forms were found with MTf, the apo-form and the N-monoferric holo-protein, suggesting a single high-affinity site. The presence of a single Fe(III)-binding site was also supported by EPR results which indicated that the Fe(III)-binding characteristics of MTf were unique, but somewhat comparable to the N-lobes of human serum Tf and chicken ovo-Tf. Circular dichroism (CD) analysis indicated that, as for Tf, no changes in secondary structure could be observed upon Fe(III)-binding. The ability of MTf to bind Zn(II) was also investigated using CD which demonstrated that the single high-affinity Fe-binding site was distinct from a potential Zn(II)-binding site.     

Aberrant expression of retinol-binding protein, osteopontin and fibroblast growth factor 7 in the porcine uterine endometrium of pregnant recipients carrying embryos produced by somatic cell nuclear transfer

The technique of somatic cell nuclear transfer (NT) is a useful tool to produce cloned animals for various purposes, but the efficiency to generate cloned animals using this technique is still very low. To improve the low efficiency in production of cloned pigs it is critical to understand the reprogramming process during development of cloned embryos, but it is also essential to understand the uterine function interacting with the transferred cloned embryos during implantation and placentation. Thus, to understand the uterine responsiveness to NT cloned embryos during pregnancy, we investigated expression of retinol-binding protein (RBP), osteopontin (OPN) and fibroblast growth factor 7 (FGF7), which play important roles in implantation and/or maintenance of pregnancy as a transport protein, an extracellular matrix protein and a growth factor, respectively, in the uterine endometrium in pigs. The uterine tissue samples were obtained by C-section from pigs with NT cloned normal (NT-normal) embryos and NT cloned abnormal (NT-abnormal) embryos and pigs with non-NT (Non-NT) embryos at term. Immunoblot analysis showed that expression of RBP and FGF7 decreased in the uterine endometrium of recipient gilts carrying NT embryos than in the endometrium of gilts carrying Non-NT embryos. Levels of OPN protein of 70 and 45kDa were not different in between the uterine endometrium of gilts carrying Non-NT and NT-normal embryos, but in the uterine endometrium of gilts carrying NT-abnormal embryos 70 and 45kDa OPN proteins increased compared to those in the endometrium of gilts carrying Non-NT embryos. Immunohistochemistry results showed that RBP expression was lower in the endometrial glandular epithelial cells, while OPN expression was higher in the endometrial luminal epithelial cells of the uterus of gilts carrying NT embryos than in the uterus of gilts carrying Non-NT embryos. Results of this study showed that maternal uterine genes were aberrantly expressed in the uterine endometrium of gilts carrying NT cloned embryos in varying degrees depending on the normality of the developing embryos. These results indicate that abnormal maternal-fetal interactions of the uterus carrying the developing NT cloned embryos may cause problems in development of cloned embryos.     

Modeling the Growth/No-Growth Boundaries of Postprocessing Listeria monocytogenes Contamination on Frankfurters and Bologna Treated with Lactic Acid

This study developed models to predict lactic acid concentration, dipping time, and storage temperature combinations determining growth/no-growth interfaces of Listeria monocytogenes at desired probabilities on bologna and frankfurters. L. monocytogenes was inoculated on bologna and frankfurters, and 75 combinations of lactic acid concentrations, dipping times, and storage temperatures were tested. Samples were stored in vacuum packages for up to 60 days, and bacterial populations were enumerated on tryptic soy agar plus 0.6% yeast extract and Palcam agar on day zero and at the end point of storage. The combinations that allowed L. monocytogenes increases of ≥1 log CFU/cm² were assigned the value of 1 (growth), and the combinations that had increases of <l log CFU/cm² were given the value of 0 (no growth). These binary growth response data were fitted to logistic regression to develop a model predicting probabilities of growth. Validation with existing data and various indices showed acceptable model performance. Thus, the models developed in this study may be useful in determining probabilities of growth and in selecting lactic acid concentrations and dipping times to control L. monocytogenes growth on bologna and frankfurters, while the procedures followed may also be used to develop models for other products, conditions, or pathogens.