Local Certification of Some Geometric Intersection Graph Classes

In the context of distributed certification, the recognition of graph classes has started to be intensively studied. For instance, different results related to the recognition of planar, bounded tree-width and $H$-minor free graphs have been recently obtained. The goal of the present work is to design compact certificates for the local recognition of relevant geometric intersection graph classes, namely interval, chordal, circular arc, trapezoid and permutation. More precisely, we give proof labeling schemes recognizing each of these classes with logarithmic-sized certificates. We also provide tight logarithmic lower bounds on the size of the certificates on the proof labeling schemes for the recognition of any of the aforementioned geometric intersection graph classes

Data transmission in long-range dielectric-loaded surface plasmon polariton waveguides

In this paper we report successful transmission of 10 Gbit/s on-off-keying (OOK) modulated signal through the LR-DLSPPWs with almost negligible degradation of the data flow consistenc

Elevated CO2 improved the growth of a double nitrate reductase defective mutant of Arabidopsis thaliana: the importance of maintaining a high energy status

Impairments in leaf nitrogen (N) assimilation in C3 plants have been identified as processes conditioning photosynthesis under elevated [CO2], especially when N is supplied as nitrate. Leaf N status is usually improved under ammonium nutrition and elevated [CO2]. However, ammonium fertilization is usually accompanied by the appearance of oxidative stress symptoms, which constrains plant development. To understand how the limitations of direct fertilization with ammonium (growth reduction attributed to ammonium toxicity) can be overcome, the effects of elevated [CO2] (800 ppm) exposure were studied in the Arabidopsis thaliana double nitrate reductase defective mutant, nia1-1/chl3-5 (which preferentially assimilates ammonium as its nitrogen source). Analysis of the physiology, metabolites and gene expression was carried out in roots and shoot organs. Our study clearly showed that elevated [CO2] improved the inhibited phenotype of the nitrate reductase double mutant. Both the photosynthetic rates and the leaf N content of the NR mutant under elevated CO2 were similar to wild type plants. The growth of the nitrate reductase mutant was linked to its ability to overcome ammonium-associated photoinhibition processes at 800 ppm [CO2]. More specifically: (i) the capacity of NR mutants to equilibrate energy availability, as reflected by the electron transport equilibrium reached (photosynthesis, photorespiration and respiration), (ii) as well as by the upregulation of genes involved in stress tolerance were identified as the processes involved in the improved performance of NR mutants

Investigations on NbTi superconducting racetrack coils under pulsed-current excitations

One of the key issues in the technology of superconductors is the protection against quenches. When designing a superconductor as a magnet, a coil or even current leads, the design should be made such that the superconductor withstands all operational conditions as fast discharges, pulsed loads or even rapid transient background fields. Computational modeling of pulsed-current characterization in a self-field NbTi racetrack sample coil has been performed using the finite element modelling software Opera as a step towards understanding the thermal and electromagnetic processes during a quench. The pulse was modelled to be generated by discharging a capacitor into an RLC circuit, which includes the NbTi racetrack coil as the sample under test. The coil was driven to the resistive state and the quench occurred by applying the pulse with a peak value exceeding the critical current of the sample coil. This contribution presents the results obtained from investigating a pulsed NbTi coil in a model based on an electromagnetic analysis. In addition, a comparison to the theoretical expectations derived for the damped oscillations in the pulse-driving circuit is given. Finally, the results from a coupled analysis, where both thermal and electromagnetic properties are being considered, within a quench multi-physics study are presented

Prospects for photon science and beam dynamics studies of a THz undulator at FLUTE

n recent years the interest in high intensity, short-pulse coherent THz radiation for non-linear experimental research and applications grew with upcoming high intensity lasers. In contrast to lasers, accelerators provide free electrons for which emission properties can be tailored to the demand at typically much higher repetition rates than high-intensity lasers can provide. Efforts are ongoing to augment short-bunch accelerators such as the European XFEL with THz radiation sources such as undulators. At the far-infrared linac and test experiment (FLUTE) at KIT, we can facil- itate experiments to investigate coherent THz radiation from different sources and provide short electron bunches. As an additional THz source, a superconducting undulator can be inserted and investigated. In this contribution, we evaluate the opportunities of this THz undulator at FLUTE for linear accelerators and FELs in terms of photon science and beam dynamics

Energy deposition simulations for a damage experiment with superconducting sample coils

An experiment to study damage caused by the impact of 440 GeV/c protons on sample superconducting racetrack coils made from NbTi and Nb3Sn strands was recently carried out at CERN\u27s HiRadMat facility. This paper reports on the detailed Monte Carlo simulations performed with FLUKA and Geant4 to evaluate the energy deposition of the 440 GeV/c proton beam on the sample coils positioned in the experimental setup. using the measured beam parameters during the experiment. The measured hotspot temperatures and temperature gradients reached in the sample coils are presented and compared with the simulations. In addition, comparisons between the simulation results from FLUKA and Geant4 are discussed in detail

Anomalous high-temperature superconductivity in YH6_6

Pressure-stabilized hydrides are a new rapidly growing class of high-temperature superconductors which is believed to be described within the conventional phonon-mediated mechanism of coupling. Here we report the synthesis of yttrium hexahydride Im3m-YH$_6$ that demonstrates the superconducting transition with T$_c$ = 224 K at 166 GPa, much lower than the theoretically predicted (>270 K). The measured upper critical magnetic field B$_c$$_2$(0) of YH$_6$ was found to be 116-158 T, which is 2-2.5 times larger than the calculated value. A pronounced shift of T$_c$ in yttrium deuteride YD$_6$ with the isotope coefficient 0.4 supports the phonon-assisted superconductivity. Current-voltage measurements showed that the critical current I$_c$ and its density J$_c$ may exceed 1.75 A and 3500 A/mm$^2$ at 0 K, respectively, which is comparable with the parameters of commercial superconductors, such as NbTi and YBCO. The superconducting density functional theory (SCDFT) and anharmonic calculations suggest unusually large impact of the Coulomb repulsion in this compound. The results indicate notable departures of the superconducting properties of the discovered YH$_6$ from the conventional Migdal-Eliashberg and Bardeen-Cooper-Schrieffer theories.Comment: arXiv admin note: text overlap with arXiv:1902.1020

Intranasal Delivery of MVA Vector Vaccine Induces Effective Pulmonary Immunity Against SARS-CoV-2 in Rodents

Antigen-specific tissue-resident memory T cells (Trms) and neutralizing IgA antibodies provide the most effective protection of the lungs from viral infections. To induce those essential components of lung immunity against SARS-CoV-2, we tested various immunization protocols involving intranasal delivery of a novel Modified Vaccinia virus Ankara (MVA)-SARS-2-spike vaccine candidate. We show that a single intranasal MVA-SARS-CoV-2-S application in mice strongly induced pulmonary spike-specific CD8+ T cells, albeit restricted production of neutralizing antibodies. In prime-boost protocols, intranasal booster vaccine delivery proved to be crucial for a massive expansion of systemic and lung tissue-resident spike-specific CD8+ T cells and the development of Th1 - but not Th2 - CD4+ T cells. Likewise, very high titers of IgG and IgA anti-spike antibodies were present in serum and broncho-alveolar lavages that possessed high virus neutralization capacities to all current SARS-CoV-2 variants of concern. Importantly, the MVA-SARS-2-spike vaccine applied in intramuscular priming and intranasal boosting treatment regimen completely protected hamsters from developing SARS-CoV-2 lung infection and pathology. Together, these results identify intramuscular priming followed by respiratory tract boosting with MVA-SARS-2-S as a promising approach for the induction of local, respiratory as well as systemic immune responses suited to protect from SARS-CoV-2 infections

A reexamination of information theory-based methods for DNA-binding site identification

<p>Abstract</p> <p>Background</p> <p>Searching for transcription factor binding sites in genome sequences is still an open problem in bioinformatics. Despite substantial progress, search methods based on information theory remain a standard in the field, even though the full validity of their underlying assumptions has only been tested in artificial settings. Here we use newly available data on transcription factors from different bacterial genomes to make a more thorough assessment of information theory-based search methods.</p> <p>Results</p> <p>Our results reveal that conventional benchmarking against artificial sequence data leads frequently to overestimation of search efficiency. In addition, we find that sequence information by itself is often inadequate and therefore must be complemented by other cues, such as curvature, in real genomes. Furthermore, results on skewed genomes show that methods integrating skew information, such as <it>Relative Entropy</it>, are not effective because their assumptions may not hold in real genomes. The evidence suggests that binding sites tend to evolve towards genomic skew, rather than against it, and to maintain their information content through increased conservation. Based on these results, we identify several misconceptions on information theory as applied to binding sites, such as negative entropy, and we propose a revised paradigm to explain the observed results.</p> <p>Conclusion</p> <p>We conclude that, among information theory-based methods, the most unassuming search methods perform, on average, better than any other alternatives, since heuristic corrections to these methods are prone to fail when working on real data. A reexamination of information content in binding sites reveals that information content is a compound measure of search and binding affinity requirements, a fact that has important repercussions for our understanding of binding site evolution.</p