Cannibalism in a small growth stage of the Early Permian branchiosaurid <i>Apateon gracilis</i> (Credner, 1881) from Saxony

An almost complete specimen of the branchiosaurid temnospondyl Apateon gracilis (Credner, 1881) with a skull length of approximately 7 mm from the Early Permian Döhlen Basin in Saxony is described that possesses a nearly complete conspecific specimen of approximately 4 mm skull length in its digestive tract. This is the first evidence of cannibalistic behaviour in small growth stages of branchiosaurids, whose dentition and hyobranchial morphology suggest adaptations to the capture of small invertebrates and feeding on small phyto- and zooplankton by filtering from the water. Therefore, cannibalism in small branchiosaurids certainly represents an exceptional case, possibly triggered by unfavourable environmental conditions. doi:10.1002/mmng.200800006</a

Three human cell types respond to multi-walled carbon nanotubes and titanium dioxide nanobelts with cell-specific transcriptomic and proteomic expression patterns

The growing use of engineered nanoparticles (NPs) in commercial and medical applications raises the urgent need for tools that can predict NP toxicity. We conducted global transcriptome and proteome analyses of three human cell types, exposed to two high aspect ratio NP types, to identify patterns of expression that might indicate high vs. low NP toxicity. Three cell types representing the most common routes of human exposure to NPs, including macrophage like (THP-1), small airway epithelial (SAE), and intestinal (Caco-2/HT29-MTX) cells, were exposed to TiO2 nanobelts (TiO2-NB; high toxicity) and multi-walled carbon nanotubes (MWCNT; low toxicity) at low (10 μg/ml) and high (100 μg/ml) concentrations for 1 and 24 h. Unique patterns of gene and protein expressions were identified for each cell type, with no differentially expressed (p<0.05, 1.5-fold change) genes or proteins overlapping across all three cell types. While unique to each cell-type, the early response was primarily independent of NP type, showing similar expression patterns in response to both TiO2-NB and MWCNT. The early response might therefore indicate a general response to insult. In contrast, the 24 h response was unique to each NP type. The most significantly (p<0.05) enriched biological processes in THP-1 cells indicated TiO2-NB regulation of pathways associated with inflammation, apoptosis, cell cycle arrest, DNA replication stress and genomic instability, while MWCNT regulated pathways indicating increased cell proliferation, DNA repair and anti-apoptosis. These two distinct sets of biological pathways might therefore underlie cellular responses to high and low NP toxicity, respectively

Detergents and chaotropes for protein solubilization before two-dimensional electrophoresis

Because of the outstanding ability of two-dimensional electrophoresis to separate complex mixtures of intact proteins, it would be advantageous to apply it to all types of proteins, including hydrophobic and membrane proteins. Unfortunately, poor solubility hampers the analysis of these molecules. As these problems arise mainly in the extraction and isoelectric focusing steps, the solution is to improve protein solubility under the conditions prevailing during isoelectric focusing. This chapter describes the use of chaotropes and novel detergents to enhance protein solubility during sample extraction and isoelectric focussing, and discusses the contribution of these compounds to improving proteomic analysis of membrane proteins

Measurement of the proton and deuteron structure functions, F2p and F2d, and of the ratio sigma(L)/sigma(T)

The muon-proton and muon-deuteron inclusive deep inelastic scattering cross sections were measured in the kinematic range 0.002 < x < 0.60 and 0.5 < Q2 < 75 GeV2 at incident muon energies of 90, 120, 200 and 280 GeV. These results are based on the full data set collected by the New Muon Collaboration, including the data taken with a small angle trigger. The extracted values of the structure functions F2p and F2d are in good agreement with those from other experiments. The data cover a sufficient range of y to allow the determination of the ratio of the longitudinally to transversely polarised virtual photon absorption cross sections, R= sigma(L)/sigma(T), for 0.002 < x < 0.12 . The values of R are compatible with a perturbative QCD prediction; they agree with earlier measurements and extend to smaller x.Comment: In this replacement the erroneously quoted R values in tables 3-6 for x>0.12, and R1990 values in tables 5-6 for all x, have been corrected, and the cross sections in tables 3-4 have been adapted. Everything else, including the structure functions F2, remained unchanged. 22 pages, LateX, including figures, with two .sty files, and three separate f2tab.tex files for the F2-tables. Accepted for publication in Nucl.Phys.B 199