Drivers of temporal changes in temperate forest plant diversity vary across spatial scales

Global biodiversity is affected by numerous environmental drivers. Yet, the extent to which global environmental changes contribute to changes in local diversity is poorly understood. We investigated biodiversity changes in a meta‐analysis of 39 resurvey studies in European temperate forests (3988 vegetation records in total, 17–75 years between the two surveys) by assessing the importance of (i) coarse‐resolution (i.e., among sites) vs. fine‐resolution (i.e., within sites) environmental differences and (ii) changing environmental conditions between surveys. Our results clarify the mechanisms underlying the direction and magnitude of local‐scale biodiversity changes. While not detecting any net local diversity loss, we observed considerable among‐site variation, partly explained by temporal changes in light availability (a local driver) and density of large herbivores (a regional driver). Furthermore, strong evidence was found that presurvey levels of nitrogen deposition determined subsequent diversity changes. We conclude that models forecasting future biodiversity changes should consider coarse‐resolution environmental changes, account for differences in baseline environmental conditions and for local changes in fine‐resolution environmental conditions.     

The Association between Multiple Sources of Information and Risk Perceptions of Tuberculosis,Ntcheu District,Malawi

Background

Tuberculosis (TB) is one of the main causes of death in developing countries. Awareness and perception of risk of TB could influence early detection, diagnosis and care seeking at treatment centers. However, perceptions about TB are influenced by sources of information.

Aim

This study aimed to determine the association between multiple sources of information, and perceptions of risk of TB among adults aged 18–49 years.

Methods

A cross-sectional study was conducted in Ntcheu district in Malawi. A total of 121 adults were sampled in a three-stage simple random sampling technique. Data were collected using a structured questionnaire. Perceptions of risk were measured using specific statements that reflected common myths and misconceptions. Low risk perception implied a person having strong belief in myths and misconceptions about TB and high risk perception meant a person having no belief in myths or misconceptions and demonstrated understanding of the disease.

Results

Females were more likely to have low risk perceptions about TB compared to males (67.7% vs. 32.5%, p = 0.01). The higher the household asset index the more likely an individual had higher risk perceptions about TB (p = 0.006). The perception of risk of TB was associated with sources of information (p = 0.03). Use of both interpersonal communication and mass media was 2.8 times more likely to be associated with increased perception of risk of TB (Odds Ratio [OR] = 2.8; 95% Confidence interva1[CI]: 3.1–15. 6; p = 0.01). After adjusting for sex and asset ownership, use of interpersonal communication and mass media were more likely to be associated with higher perception of risk of TB (OR, 2.0; 95% CI: 1.65–10.72; p = 0.003) compared with interpersonal communication only (OR 1.6, 95%; CI: 1.13–8.98, p = 0.027).

Conclusion

The study found that there was association between multiple sources of information, and higher perceptions of risk of TB among adults aged 18–49 years.     

Impact of food processing and detoxification treatments on mycotoxin contamination

Mycotoxins are fungal metabolites commonly occurring in food, which pose a health risk to the consumer. Maximum levels for major mycotoxins allowed in food have been established worldwide. Good agricultural practices, plant disease management, and adequate storage conditions limit mycotoxin levels in the food chain yet do not eliminate mycotoxins completely. Food processing can further reduce mycotoxin levels by physical removal and decontamination by chemical or enzymatic transformation of mycotoxins into less toxic products. Physical removal of mycotoxins is very efficient: manual sorting of grains, nuts, and fruits by farmers as well as automatic sorting by the industry significantly lowers the mean mycotoxin content. Further processing such as milling, steeping, and extrusion can also reduce mycotoxin content. Mycotoxins can be detoxified chemically by reacting with food components and technical aids; these reactions are facilitated by high temperature and alkaline or acidic conditions. Detoxification of mycotoxins can also be achieved enzymatically. Some enzymes able to transform mycotoxins naturally occur in food commodities or are produced during fermentation but more efficient detoxification can be achieved by deliberate introduction of purified enzymes. We recommend integrating evaluation of processing technologies for their impact on mycotoxins into risk management. Processing steps proven to mitigate mycotoxin contamination should be used whenever necessary. Development of detoxification technologies for high-risk commodities should be a priority for research. While physical techniques currently offer the most efficient post-harvest reduction of mycotoxin content in food, biotechnology possesses the largest potential for future developments.     

Macromolecular isoforms of Daphnia magna haemoglobin

The haemoglobin (Hb) of Daphnia magna acclimated to different oxygen conditions was sampled, and in its natively assembled state it was separated by chromatofocusing. The Hb isoforms were analysed for their subunit composition under denaturating conditions by two-dimensional gel electrophoresis. The Hb system is suggested to consist of three predominant Hb aggregates, which are characterised by a specific subunit composition and synthesised in response to different ambient oxygen conditions. In normoxia, a dominant Hb aggregate (DmHbI) with a pI of 4.4-4.6 was composed of subunits B, C, E, F and G. In severe hypoxia, a different dominant Hb isoform (DmHbIII) with a pI of 5.7-5.9 was composed of subunits A, B, C, D, E and F. Further analyses in moderate hypoxia provided evidence for a third Hb isoform (DmHbII) composed of subunits B, C, D, E and F. Sequence alignment and homology modelling of the tertiary structure of the D. magna Hb domains 1 and 2 revealed functionally relevant substitutions of amino acid residues at positions B10, E7 and E11, which determine the functional properties of D. magna haemoglobin in terms of haem contact, oxygen binding and affinity. Both domains are predicted to possess the common haemoglobin fold, but helices C and D are not properly formed, and helix G is interrupted by a short coil.     

A bryozoan fauna from the Santa Lucia Formation (Lower–Middle Devonian) of Cantabrian Mountains,NW Spain

The Lower to Middle Devonian Santa Lucia Formation of NW Spain contains a rich and well-preserved bryozoan fauna. An assemblage containing 14 species is described from two localities in Cantabrian Mountains, Abelgas, and Paradilla. One new genus with one new species is described: Isostylus abelgasensis n. sp. n. gen. Another two new species have been found: Microcampylus minor n. sp. and Acanthoclema parvula n. sp. Additionally, the following species were identified: Cyclotrypa communis (Ulrich 1890), Fistuliphragma gracilis Ernst 2008a, Leioclema attenuatum Duncan 1939, Hemitrypa cf. tenella Barrande in Počta 1894, Fenestella aff. parallela Hall 1881, Anastomopora adnata (Hall 1883), Semicoscinium rhombicum Ulrich 1890, Quadrisemicoscinium discretum (Prantl 1932). Three species are described in open nomenclature: Trepostomata sp. indet.1 and 2, and Semicoscinium sp. The described bryozoan fauna shows connections to the Lower Devonian of Bohemia, and to the Middle Devonian of Rhenish Massif and North America.     

Kinetics of the interactions between yeast elongation factors 1A and 1Balpha, guanine nucleotides, and aminoacyl-tRNA

The interactions of elongation factor 1A (eEF1A) from Saccharomyces cerevisiae with elongation factor 1Balpha (eEF1Balpha), guanine nucleotides, and aminoacyl-tRNA were studied kinetically by fluorescence stopped-flow. eEF1A has similar affinities for GDP and GTP, 0.4 and 1.1 microm, respectively. Dissociation of nucleotides from eEF1A in the absence of the guanine nucleotide exchange factor is slow (about 0.1 s(-1)) and is accelerated by eEF1Balpha by 320-fold and 250-fold for GDP and GTP, respectively. The rate constant of eEF1Balpha binding to eEF1A (10(7)-10(8) M (-1) s(-1)) is independent of guanine nucleotides. At the concentrations of nucleotides and factors prevailing in the cell, the overall exchange rate is expected to be in the range of 6 s(-1), which is compatible with the rate of protein synthesis in the cell. eEF1A.GTP binds Phe-tRNA(Phe) with a K(d) of 3 nm, whereas eEF1A.GDP shows no significant binding, indicating that eEF1A has similar tRNA binding properties as its prokaryotic homolog, EF-Tu.     

Biochemical functionalization of polymeric cell substrata can alter mechanical compliance

Biochemical functionalization of surfaces is an increasingly utilized mechanism to promote or inhibit adhesion of cells. To promote mammalian cell adhesion, one common functionalization approach is surface conjugation of adhesion peptide sequences such as Arg-Gly-Asp (RGD), a ligand of transmembrane integrin molecules. It is generally assumed that such functionalization does not alter the local mechanical properties of the functionalized surface, as is important to interpretations of macromolecular mechanotransduction in cells. Here, we examine this assumption systematically, through nanomechanical measurement of the nominal elastic modulus of polymer multilayer films of nanoscale thickness, functionalized with RGD through different processing routes. We find that the method of biochemical functionalization can significantly alter mechanical compliance of polymeric substrata such as weak polyelectrolyte multilayers (PEMs), increasingly utilized materials for such studies. In particular, immersed adsorption of intermediate functionalization reagents significantly decreases compliance of the PEMs considered herein, whereas polymer-on-polymer stamping of these same reagents does not alter compliance of weak PEMs. This finding points to the potential unintended alteration of mechanical properties via surface functionalization and also suggests functionalization methods by which chemical and mechanical properties of cell substrata can be controlled independently.     

Activation of estrogen receptor-beta by a special extract of Rheum rhaponticum (ERr 731), its aglycones and structurally related compounds

The special extract ERr 731^® from the roots of Rheum rhaponticum is the major constituent of Phytoestrol^® N which is used for the treatment of climacteric symptoms in menopausal women. However, the molecular mode of action of ERr 731^® was unknown. For the first time, ERr 731^® and its aglycones trans-rhapontigenin and desoxyrhapontigenin were investigated with regard to the activation of the estrogen receptor- or estrogen receptor-β (ER, ERβ). The related hydroxystilbenes cis-rhapontigenin, resveratrol and piceatannol were studied as comparators. As controls, 17β-estradiol or the selective ER-(propylpyrazoltriol) or ERβ-agonists (diarylpropionitril) were used. Neither in ER-expressing yeast cells, in the ER-responsive Ishikawa cells, nor in human endometrial HEC-1B cells transiently transfected with the ER an activation of ER by ERr 731^® or the other single compounds was detected. Furthermore, an antiestrogenic effect was not observed. In contrast in human endometrial HEC-1B cells transiently transfected with the ERβ, 100 ng/ml ERr 731^® and the single compounds significantly induced the ERβ-coupled luciferase activity in a range comparable to 10⁻⁸ M 17β-estradiol. All effects were abolished with the pure ER antagonist ICI 182780, indicating an ER-specific effect. The ERβ agonistic activity by ERr 731^® could be of importance for its clinical use, as central functions relevant to climacteric complaints are proposed to be mediated via ERβ activation.     

ProfDist: a tool for the construction of large phylogenetic trees based on profile distances

SUMMARY: ProfDist is a user-friendly software package using the profile-neighbor-joining method (PNJ) in inferring phylogenies based on profile distances on DNA or RNA sequences. It is a tool for reconstructing and visualizing large phylogenetic trees providing new and standard features with a special focus on time efficency, robustness and accuracy. AVAILABILITY: A Windows version of ProfDist comes with a graphical user interface and is freely available at http://profdist.bioapps.biozentrum.uni-wuerzburg.de     

Progesterone-induced blocking factor activates STAT6 via binding to a novel IL-4 receptor

Progesterone-induced blocking factor (PIBF) induces Th2-dominant cytokine production. Western blotting and EMSA revealed phosphorylation as well as nuclear translocation of STAT6 and inhibition of STAT4 phosphorylation in PIBF-treated cells. The silencing of STAT6 by small interfering RNA reduced the cytokine effects. Because the activation of the STAT6 pathway depends on the ligation of IL-4R, we tested the involvement of IL-4R in PIBF-induced STAT6 activation. Although PIBF does not bind to IL-4R, the blocking of the latter with an Ab abolished PIBF-induced STAT6 activation, whereas the blocking of the IL-13R had no effect. PIBF activated suppressor of cytokine signaling-3 and inhibited IL-12-induced suppressor of cytokine signaling-1 activation. The blocking of IL-4R counteracted all the described effects, suggesting that the PIBF receptor interacts with IL-4R alpha-chain, allowing PIBF to activate the STAT6 pathway. PIBF did not phosphorylate Jak3, suggesting that the gamma-chain is not needed for PIBF signaling. Confocal microscopic analysis revealed a colocalization and at 37 degrees C a cocapping of the FITC PIBF-activated PIBF receptor and PE anti-IL-4R-labeled IL-4R. After the digestion of the cells with phosphatidylinositol-specific phospholipase C, the STAT6-activating effect of PIBF was lost, whereas that of IL-4 remained unaltered. These data suggest the existence of a novel type of IL-4R composed of the IL-4R alpha-chain and the GPI-anchored PIBF receptor.