360 research outputs found
The bar involution for quantum symmetric pairs
We construct a bar involution for quantum symmetric pair coideal subalgebras
corresponding to involutive automorphisms of the
second kind of symmetrizable Kac-Moody algebras. To this end we give unified
presentations of these algebras in terms of generators and relations extending
previous results by G. Letzter and the second named author. We specify
precisely the set of parameters for which such an intrinsic bar
involution exists.Comment: Minor revision: proof of Proposition 2.3 expanded; added new Remarks
2.8, 3.1, and 3.14; simplified base field in Section 3.3; typos corrected;
final version; 25 page
Grave Action: Last Rites in Brechtâs "Mother Courage" and Beckettâs "Endgame"
Against the background of Brechtâs de-familiarization (epic theater) and Beckettâs tragicomedy (absurdist theater), this essay compares scenes of incapacitation and mutilation, of deaths and corpses, shrouds and burials in Mother Courage and Endgame. It places its specific emphasis on the last rites, which, whether granted or refused, relentlessly permeate both plays. This comparison of two exilic plays about loss is based in obvious difference (e.g. in setting, character constellation, and, to some degree, in dramatic intention), as well as in resemblance (e.g. the two playwrightsâ shared interest in distancing). Mother Courage and Endgame are marked by the ghostly ubiquity of violence, and portray in complex fashion the human struggle with the barest of realities: death.Against the background of Brechtâs de-familiarization (epic theater) and Beckettâs tragicomedy (absurdist theater), this essay compares scenes of incapacitation and mutilation, of deaths and corpses, shrouds and burials in Mother Courage and Endgame. It places its specific emphasis on the last rites, which, whether granted or refused, relentlessly permeate both plays. This comparison of two exilic plays about loss is based in obvious difference (e.g. in setting, character constellation, and, to some degree, in dramatic intention), as well as in resemblance (e.g. the two playwrightsâ shared interest in distancing). Mother Courage and Endgame are marked by the ghostly ubiquity of violence, and portray in complex fashion the human struggle with the barest of realities: death
Echo Revisited: Incapacitation, Exploitation, Reverberation
The world of the past and those civilisations that preceded ours is no longer. Our poems and stories cannot comfortably stage anymore âfresche, chiare et dolci acqueâ like those in Francesco Petrarcaâs famous poem, where they appear as a harmonious background for characters of the natural kingdom. Today, they capitulate instead to the presence of contaminated waters bearing the signs of impending death or incipient destruction. Such are our expanses. In our world, Echo, the still disdained nymph in love with prideful and haughty-hearted Narcissus, can no longer naturally inhabit a landscape of unspoiled beauty. Instead, she finds herself residing in woods and along rivers soiled with filth, darkly tinted, and increasingly subject to human dominion. To phrase things differently, in our time and day, Echo, incapacitated herself, would dwell in a waste land of incapacitation, exploitation and death
Cosmological data and indications for new physics
Data from the Atacama Cosmology Telescope (ACT) and the South Pole Telescope
(SPT), combined with the nine-year data release from the WMAP satellite,
provide very precise measurements of the cosmic microwave background (CMB)
angular anisotropies down to very small angular scales. Augmented with
measurements from Baryonic Acoustic Oscillations surveys and determinations of
the Hubble constant, we investigate whether there are indications for new
physics beyond a Harrison-Zel'dovich model for primordial perturbations and the
standard number of relativistic degrees of freedom at primordial recombination.
All combinations of datasets point to physics beyond the minimal
Harrison-Zel'dovich model in the form of either a scalar spectral index
different from unity or additional relativistic degrees of freedom at
recombination (e.g., additional light neutrinos). Beyond that, the extended
datasets including either ACT or SPT provide very different indications: while
the extended-ACT (eACT) dataset is perfectly consistent with the predictions of
standard slow-roll inflation, the extended-SPT (eSPT) dataset prefers a
non-power-law scalar spectral index with a very large variation with scale of
the spectral index. Both eACT and eSPT favor additional light degrees of
freedom. eACT is consistent with zero neutrino masses, while eSPT favors
nonzero neutrino masses at more than 95% confidence.Comment: 13 pages, 5 figures, 2 table
Auxin methylation is required for differential growth in Arabidopsis
Asymmetric auxin distribution is instrumental for the differential growth that causes organ bending on tropic stimuli and curvatures during plant development. Local differences in auxin concentrations are achieved mainly by polarized cellular distribution of PIN auxin transporters, but whether other mechanisms involving auxin homeostasis are also relevant for the formation of auxin gradients is not clear. Here we show that auxin methylation is required for asymmetric auxin distribution across the hypocotyl, particularly during its response to gravity. We found that loss-of-function mutants in Arabidopsis IAA CARBOXYL METHYLTRANSFERASE1 (IAMT1) prematurely unfold the apical hook, and that their hypocotyls are impaired in gravitropic reorientation. This defect is linked to an auxin-dependent increase in PIN gene expression, leading to an increased polar auxin transport and lack of asymmetric distribution of PIN3 in the iamt1 mutant. Gravitropic reorientation in the iamt1 mutant could be restored with either endodermis-specific expression of IAMT1 or partial inhibition of polar auxin transport, which also results in normal PIN gene expression levels. We propose that IAA methylation is necessary in gravity-sensing cells to restrict polar auxin transport within the range of auxin levels that allow for differential responses
Symmetry-Resolved CO Desorption and Oxidation Dynamics on O/Ru(0001) Probed at the C K-edge by Ultrafast X-Ray Spectroscopy
We report on carbon monoxide desorption and oxidation induced by 400 nm femtosecond laser excitation on the O/Ru(0001) surface probed by time-resolved x-ray absorption spectroscopy (TR-XAS) at the carbon K-edge. The experiments were performed under constant background pressures of CO (6 Ă 10â8 Torr) and O2 (3 Ă 10â8 Torr). Under these conditions, we detect two transient CO species with narrow 2Ï* peaks, suggesting little 2Ï* interaction with the surface. Based on polarization measurements, we find that these two species have opposing orientations: (1) CO favoring a more perpendicular orientation and (2) CO favoring a more parallel orientation with respect to the surface. We also directly detect gas-phase CO2 using a mass spectrometer and observe weak signatures of bent adsorbed CO2 at slightly higher x-ray energies than the 2Ï* region. These results are compared to previously reported TR-XAS results at the O K-edge, where the CO background pressure was three times lower (2 Ă 10â8 Torr) while maintaining the same O2 pressure. At the lower CO pressure, in the CO 2Ï* region, we observed adsorbed CO and a distribution of OCâO bond lengths close to the CO oxidation transition state, with little indication of gas-like CO. The shift toward âgas-likeâ CO species may be explained by the higher CO exposure, which blocks O adsorption, decreasing O coverage and increasing CO coverage. These effects decrease the CO desorption barrier through dipoleâdipole interaction while simultaneously increasing the CO oxidation barrier
Association between variations in the TLR4 gene and incident type 2 diabetes is modified by the ratio of total cholesterol to HDL-cholesterol
<p>Abstract</p> <p>Background</p> <p>Toll-like receptor 4 (TLR4), the signaling receptor for lipopolysaccharides, is an important member of the innate immunity system. Since several studies have suggested that type 2 diabetes might be associated with changes in the innate immune response, we sought to investigate the association between genetic variants in the <it>TLR4 </it>gene and incident type 2 diabetes.</p> <p>Methods</p> <p>A case-cohort study was conducted in initially healthy, middle-aged subjects from the MONICA/KORA Augsburg studies including 498 individuals with incident type 2 diabetes and 1,569 non-cases. Seven SNPs were systematically selected in the <it>TLR4 </it>gene and haplotypes were reconstructed.</p> <p>Results</p> <p>The effect of <it>TLR4 </it>SNPs on incident type 2 diabetes was modified by the ratio of total cholesterol to high-density lipoprotein cholesterol (TC/HDL-C). In men, four out of seven <it>TLR4 </it>variants showed significant interaction with TC/HDL-C after correction for multiple testing (p < 0.01). The influence of the minor alleles of those variants on the incidence of type 2 diabetes was observed particularly for male patients with high values of TC/HDL-C. Consistent with these findings, haplotype-based analyses also revealed that the effect of two haplotypes on incident type 2 diabetes was modified by TC/HDL-C in men (p < 10<sup>-3</sup>). However, none of the investigated variants or haplotypes was associated with type 2 diabetes in main effect models without assessment of effect modifications.</p> <p>Conclusion</p> <p>We conclude that minor alleles of several <it>TLR4 </it>variants, although not directly associated with type 2 diabetes might increase the risk for type 2 diabetes in subjects with high TC/HDL-C. Additionally, our results confirm previous studies reporting sex-related dissimilarities in the development of type 2 diabetes.</p
Fine-mapping of prostate cancer susceptibility loci in a large meta-analysis identifies candidate causal variants
Prostate cancer is a polygenic disease with a large heritable component. A number of common, low-penetrance prostate cancer risk loci have been identified through GWAS. Here we apply the Bayesian multivariate variable selection algorithm JAM to fine-map 84 prostate cancer susceptibility loci, using summary data from a large European ancestry meta-analysis. We observe evidence for multiple independent signals at 12 regions and 99 risk signals overall. Only 15 original GWAS tag SNPs remain among the catalogue of candidate variants identified; the remainder are replaced by more likely candidates. Biological annotation of our credible set of variants indicates significant enrichment within promoter and enhancer elements, and transcription factor-binding sites, including AR, ERG and FOXA1. In 40 regions at least one variant is colocalised with an eQTL in prostate cancer tissue. The refined set of candidate variants substantially increase the proportion of familial relative risk explained by these known susceptibility regions, which highlights the importance of fine-mapping studies and has implications for clinical risk profiling. © 2018 The Author(s).Prostate cancer is a polygenic disease with a large heritable component. A number of common, low-penetrance prostate cancer risk loci have been identified through GWAS. Here we apply the Bayesian multivariate variable selection algorithm JAM to fine-map 84 prostate cancer susceptibility loci, using summary data from a large European ancestry meta-analysis. We observe evidence for multiple independent signals at 12 regions and 99 risk signals overall. Only 15 original GWAS tag SNPs remain among the catalogue of candidate variants identified; the remainder are replaced by more likely candidates. Biological annotation of our credible set of variants indicates significant enrichment within promoter and enhancer elements, and transcription factor-binding sites, including AR, ERG and FOXA1. In 40 regions at least one variant is colocalised with an eQTL in prostate cancer tissue. The refined set of candidate variants substantially increase the proportion of familial relative risk explained by these known susceptibility regions, which highlights the importance of fine-mapping studies and has implications for clinical risk profiling. © 2018 The Author(s).Peer reviewe
Search for dark matter produced in association with bottom or top quarks in âs = 13 TeV pp collisions with the ATLAS detector
A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fbâ1 of protonâproton collision data recorded by the ATLAS experiment at âs = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
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