741 research outputs found
From polarization of the public to polarization of the electorate: European Parliament elections as the preferred race for ideologues
This study examines the effect of voters’ ideological extremism on turnout in European national and European Parliament elections. Using data from recent European Election Studies, the Comparative Study of Electoral Systems, and other national election studies, we find that, relative to centrists, ideological extremists (measured by self-placement on the left–right scales) are more likely to vote in European Parliament elections (2014 and 2019) but not national elections. We argue that these differences stem from the fact that European Parliament elections are second-order races. The results help to explain why the European Parliament has become more polarized, even in the absence of significant changes in overall attitudes among the European public, and why extreme parties have been more successful in recent European Parliament than national elections
Shaken not stirred: a global research cocktail served in Hinxton
A report of the 2007 Cold Spring Harbor Laboratory/Wellcome Trust Conference on Functional Genomics and Systems Biology, Hinxton, UK, 10-13 October 2007
Screening von Senf-Genotypen zur Körnernutzung im ökologischen Anbau in Mitteleuropa
Information is rare about mustard (Sinapis alba, Brassica nigra, B. juncea) varieties and their characteristics for a suitable performance under organic conditions. 30 accessions were grown at the organic Research Station Kleinhohenheim in SW Germany in the year 2011. Highest grain yield was obtained by S. alba (10.5 g/plant) which was about four times the yield of B. nigra, and ten times the yield of B. juncea, mainly because of higher thousand kernel mass and high number of pods. B nigra and B. juncea were heavily damaged by pests so that only S. alba seems a suitable mustard species for German organic farming at the moment
The WTO, Agribusiness, and the Third Food Regime
Food regime theory emerged in the 1980s as a tool to delineate the history of the modern food system. Scholars insist that we have arrived at the third and putative corporate food regime that is dominated by a select group of agribusiness corporations. The corporate food regime"s ascent to dominance will be presented here as a product of the realization of neoliberal trade policies at the urging of the World Trade Organization. Initially promising development to fledgling countries, the WTO"s forays into agriculture have amounted to nothing less than a catastrophe for the Global South. The hope that developing countries would be able to trade their way out of debt has long been abandoned, and the gap between the developed and developing world has only been further exacerbated as a result of trade liberalization. Worse yet, the WTO"s Agreement on Agriculture was intentionally littered with loopholes that allow Northern countries to egregiously subsidize crops that are then exported off to Southern markets at artificially low prices, crippling local producers in the process. Through examining import and export flows in the Global South since the trade agreement, this cruel feature of the modern food system will become evident as will the subsequent jump in agribusiness" profits amid the direst of...Department of Political ScienceKatedra politologieFaculty of Social SciencesFakulta sociálních vě
Experimental study of bird strike response of sandwich structures: overall trends
Nowadays sandwich structures are used as bird shields to protect aircraft nose bulkhead. They are usually made of aluminum honeycomb and sheets. In order to optimize mass, cost and efficiency of such bird shields, aircraft manufacturers want to explore new materials and designs.
In this context, this work aims at exhibiting influences of material and design parameters on the bird strike response of sandwich structures. Based on previous finite element calculations that enabled to determine the most influential parameters, a design of experiment has been defined to span a parameter space in 4 dimensions, namely the thickness of the front skin, the thickness of the core, the yield stress of the front skin and the crushing stress of the core. 13 configurations of sandwich structures are then tested according to this design of experiment. These samples are 800 mm x 800 mm square sandwiches simply supported on a rigid square frame. The impactor is a 1.6 kg gelatin bird substitute, thrown at a speed of 160 m/s.
Based on high speed camera image correlation, an original approach is developed to measure and quantify the responses of the samples. For each configuration, the full displacement field of the rear face of the sandwich is calculated during the impact event. The final shapes for both rear and front faces of the shield are also reconstructed, enabling to compare the behaviors of the different structures regarding bending, indentation and core crushing…
The exhibited trends in terms of influences of material and design parameters open prospects for pre-selection of candidate materials and designs for bird shield applications which could lead to mass and cost reduction while satisfying aircraft design constraints (no failure, low rear face displacement…)
Clinical impact of manual scoring of peripheral arterial tonometry in patients with sleep apnea.
PURPOSE
The objective was to analyze the clinical implications of manual scoring of sleep studies using peripheral arterial tonometry (PAT) and to compare the manual and automated scoring algorithms.
METHODS
Patients with suspected sleep-disordered breathing underwent sleep studies using PAT. The recordings were analyzed using a validated automated computer-based scoring and a novel manual scoring algorithm. The two methods were compared regarding sleep stages and respiratory events.
RESULTS
Recordings of 130 patients were compared. The sleep stages and time were not significantly different between the scoring methods. PAT-derived apnea-hypopnea index (pAHI) was on average 8.4 events/h lower in the manually scored data (27.5±17.4/h vs.19.1±15.2/h, p<0.001). The OSA severity classification decreased in 66 (51%) of 130 recordings. A similar effect was found for the PAT-derived respiratory disturbance index with a reduction from 31.2±16.5/h to 21.7±14.4/h (p<0.001), for automated and manual scoring, respectively. A lower pAHI for manual scoring was found in all body positions and sleep stages and was independent of gender and body mass index. The absolute difference of pAHI increased with sleep apnea severity, while the relative difference decreased. Pearson's correlation coefficient between pAHI and oxygen desaturation index (ODI) significantly improved from 0.89 to 0.94 with manual scoring (p<0.001).
CONCLUSIONS
Manual scoring results in a lower pAHI while improving the correlation to ODI. With manual scoring, the OSA category decreases in a clinically relevant proportion of patients. Sleep stages and time do not change significantly with manual scoring. In the authors' opinion, manual oversight is recommended if clinical decisions are likely to change
Differential patterns of intronic and exonic DNA regions with respect to RNA polymerase II occupancy, nucleosome density and H3K36me3 marking in fission yeast
BACKGROUND: The generation of mature mRNAs involves interconnected processes, including transcription by RNA polymerase II (Pol II), modification of histones, and processing of pre-mRNAs through capping, intron splicing, and polyadenylation. These processes are thought to be integrated, both spatially and temporally, but it is unclear how these connections manifest at a global level with respect to chromatin patterns and transcription kinetics. We sought to clarify the relationships between chromatin, transcription and splicing using multiple genome-wide approaches in fission yeast. RESULTS: To investigate these functional interdependencies, we determined Pol II occupancy across all genes using high-density tiling arrays. We also performed ChIP-chip on the same array platform to globally map histone H3 and its H3K36me3 modification, complemented by formaldehyde-assisted isolation of regulatory elements (FAIRE). Surprisingly, Pol II occupancy was higher in introns than in exons, and this difference was inversely correlated with gene expression levels at a global level. Moreover, introns showed distinct distributions of histone H3, H3K36me3 and FAIRE signals, similar to those at promoters and terminators. These distinct transcription and chromatin patterns of intronic regions were most pronounced in poorly expressed genes. CONCLUSIONS: Our findings suggest that Pol II accumulates at the 3 ends of introns, leading to substantial transcriptional delays in weakly transcribed genes. We propose that the global relationship between transcription, chromatin remodeling, and splicing may reflect differences in local nuclear environments, with highly expressed genes being associated with abundant processing factors that promote effective intron splicing and transcriptional elongation
Modeling DNA beacons at the mesoscopic scale
We report model calculations on DNA single strands which describe the
equilibrium dynamics and kinetics of hairpin formation and melting. Modeling is
at the level of single bases. Strand rigidity is described in terms of simple
polymer models; alternative calculations performed using the freely rotating
chain and the discrete Kratky-Porod models are reported. Stem formation is
modeled according to the Peyrard-Bishop-Dauxois Hamiltonian. The kinetics of
opening and closing is described in terms of a diffusion-controlled motion in
an effective free energy landscape. Melting profiles, dependence of melting
temperature on loop length, and kinetic time scales are in semiquantitative
agreement with experimental data obtained from fluorescent DNA beacons forming
poly(T) loops. Variation in strand rigidity is not sufficient to account for
the large activation enthalpy of closing and the strong loop length dependence
observed in hairpins forming poly(A) loops. Implications for modeling single
strands of DNA or RNA are discussed.Comment: 15 pages, 17 figures, submitted to Eur. J. Phys.
Elasticity of semi-flexible polymers
We present a numerical solution of the Worm-Like Chain (WLC) model for
semi-flexible polymers. We display graphs for the end-to-end distance
distribution and the force-extension relation expected from the model. We
predict the expected level of fluctuations around the mean value in
force-extension curves. Our treatment analyses the entire range of polymer
lengths and reproduces interesting qualitative features seen in recent computer
simulations for polymers of intermediate length. These results can be tested
against experiments on single molecules. This study is relevant to mechanical
properties of biological molecules.Comment: five pages revtex five figures, slightly improved version with recent
references adde
- …