Convolutional Codes in Rank Metric with Application to Random Network Coding

Random network coding recently attracts attention as a technique to disseminate information in a network. This paper considers a non-coherent multi-shot network, where the unknown and time-variant network is used several times. In order to create dependencies between the different shots, particular convolutional codes in rank metric are used. These codes are so-called (partial) unit memory ((P)UM) codes, i.e., convolutional codes with memory one. First, distance measures for convolutional codes in rank metric are shown and two constructions of (P)UM codes in rank metric based on the generator matrices of maximum rank distance codes are presented. Second, an efficient error-erasure decoding algorithm for these codes is presented. Its guaranteed decoding radius is derived and its complexity is bounded. Finally, it is shown how to apply these codes for error correction in random linear and affine network coding.Comment: presented in part at Netcod 2012, submitted to IEEE Transactions on Information Theor

Nanoparticle detection in an open-access silicon microcavity

We report on the detection of free nanoparticles in a micromachined, open-access Fabry-P\'erot microcavity. With a mirror separation of $130\,\mu$m, a radius of curvature of $1.3\,$mm, and a beam waist of $12\,\mu$m, the mode volume of our symmetric infrared cavity is smaller than $15\,$pL. The small beam waist, together with a finesse exceeding 34,000, enables the detection of nano-scale dielectric particles in high vacuum. This device allows monitoring of the motion of individual $150\,$nm radius silica nanospheres in real time. We observe strong coupling between the particles and the cavity field, a precondition for optomechanical control. We discuss the prospects for optical cooling and detection of dielectric particles smaller than $10\,$nm in radius and $1\times10^7\,$amu in mass.Comment: 4 pages, 3 figure

Large Scale Separate Effects Tests on Hydrogen Combustion during Direct Containment Heating Events (KIT Scientific Reports ; 7663)

Combustion codes were applied to reproduce the experimental data from tests which investigate high pressure melt ejection (HPME) and direct containment heating (DCH) issue. The code calculations revealed shortcomings of the existing models which made an application of the code for reactor calculations unfeasible because of the required up-scaling. Combustion and heat loss models need further improvements. However, data from experiments at a single scale are not sufficient to reach this goal

Electron rescattering at metal nanotips induced by ultrashort laser pulses

We report on the first investigation of plateau and cut-off structures in photoelectron spectra from nano-scale metal tips interacting with few-cycle near-infrared laser pulses. These hallmarks of electron rescattering, well-known from atom-laser interaction in the strong-field regime, appear at remarkably low laser intensities with nominal Keldysh parameters of the order of $\gtrsim 10$. Quantum and quasi-classical simulations reveal that a large field enhancement near the tip and the increased backscattering probability at a solid-state target play a key role. Plateau electrons are by an order of magnitude more abundant than in comparable atomic spectra, reflecting the high density of target atoms at the surface. The position of the cut-off serves as an in-situ probe for the locally enhanced electric field at the tip apex

Radio and IR interferometry of SiO maser stars

Radio and infrared interferometry of SiO maser stars provide complementary information on the atmosphere and circumstellar environment at comparable spatial resolution. Here, we present the latest results on the atmospheric structure and the dust condensation region of AGB stars based on our recent infrared spectro-interferometric observations, which represent the environment of SiO masers. We discuss, as an example, new results from simultaneous VLTI and VLBA observations of the Mira variable AGB star R Cnc, including VLTI near- and mid-infrared interferometry, as well as VLBA observations of the SiO maser emission toward this source. We present preliminary results from a monitoring campaign of high-frequency SiO maser emission toward evolved stars obtained with the APEX telescope, which also serves as a precursor of ALMA images of the SiO emitting region. We speculate that large-scale long-period chaotic motion in the extended molecular atmosphere may be the physical reason for observed deviations from point symmetry of atmospheric molecular layers, and for the observed erratic variability of high-frequency SiO maser emissionComment: 8 pages, 4 figures, submitted to Proc. IAU Symp. 287 "Cosmic masers - from OH to H_0", R.S. Booth, E.M.L. Humphreys, W.H.T. Vlemmings (eds.), invited pape

Revisited Upper Reference Limits for Highly Sensitive Cardiac Troponin T in Relation to Age, Sex, and Renal Function

(1) Background: Highly sensitive cardiac troponin T (hs-cTnT) plays an essential role in the diagnosis of myocardial injury. The upper reference limit of the respective assay is generally applied, irrespective of age, renal function, or sex. We aimed to identify age-adjusted and sex-adjusted upper reference limits in relation to renal function in a large population-based cohort without cardiac diseases. (2) Methods: We included 5428 subjects of the population-based LIFE-Adult cohort, free of diagnosed cardiac diseases. Sex-adjusted and age-adjusted 99th percentiles for hs-cTnT in subjects with preserved renal function were obtained. (3) Results: The hs-cTnT values were higher in men of all age groups. In both sexes, an increasing age positively correlated with higher hs-cTnT values. Hs-cTnT weakly correlated with serum creatinine. The three-dimensional analysis of age, creatinine, and hs-cTnT showed no relevant additional effect of creatinine on hs-cTnT. In men aged above 60 and women above 70, the calculated 99th percentiles clearly exceeded the commonly applied thresholds. (4) Conclusion: Age and sex have a major impact on the serum concentration of hs-cTnT, while renal function does not. We propose to consider age-adjusted and sex-adjusted reference values

Atrial fibrillation is frequent but does not affect risk stratification in pulmonary embolism

Background: Although prior studies indicate a high prevalence of atrial fibrillation (AF) in patients with pulmonary embolism (PE), the exact prevalence and prognostic impact are unknown. Methods: We aimed to investigate the prevalence, risk factors and prognostic impact of AF on risk stratification, in-hospital adverse outcomes and mortality in 528 consecutive PE patients enrolled in a single-centre registry between 09/2008 and 09/2017. Results: Overall, 52 patients (9.8%) had known AF and 57 (10.8%) presented with AF on admission; of those, 34 (59.6%) were newly diagnosed with AF. Compared to patients with no AF, overt hyperthyroidism was associated with newly diagnosed AF (OR 7.89 [2.99–20.86]), whilst cardiovascular risk comorbidities were more frequently observed in patients with known AF. Patients with AF on admission had more comorbidities, presented more frequently with tachycardia and elevated cardiac biomarkers and were hence stratified to higher risk classes. However, AF on admission had no impact on in-hospital adverse outcome (8.3%) and in-hospital mortality (4.5%). In multivariate logistic regression analyses corrected for AF on admission, NT-proBNP and troponin elevation as well as higher risk classes in risk assessment models remained independent predictors of an in-hospital adverse outcome. Conclusion: Atrial fibrillation is a frequent finding in PE, affecting more than 10% of patients. However, AF was not associated with a higher risk of in-hospital adverse outcomes and did not affect the prognostic performance of risk assessment strategies. Thus, our data support the use of risk stratification tools for patients with acute PE irrespective of the heart rhythm on admission

The Arabidopsis class II sirtuin is a lysine deacetylase and interacts with mitochondrial energy metabolism

The posttranslational regulation of proteins by lysine (Lys) acetylation has recently emerged to occur not only on histones, but also on organellar proteins in plants and animals. In particular, the catalytic activities of metabolic enzymes have been shown to be regulated by Lys acetylation. The Arabidopsis (Arabidopsis thaliana) genome encodes two predicted sirtuin-type Lys deacetylases, of which only Silent Information Regulator2 homolog (SRT2) contains a predicted presequence for mitochondrial targeting. Here, we have investigated the function of SRT2 in Arabidopsis. We demonstrate that SRT2 functions as a Lys deacetylase in vitro and in vivo. We show that SRT2 resides predominantly at the inner mitochondrial membrane and interacts with a small number of protein complexes mainly involved in energy metabolism and metabolite transport. Several of these protein complexes, such as the ATP synthase and the ATP/ADP carriers, show an increase in Lys acetylation in srt2 loss-of-function mutants. The srt2 plants display no growth phenotype but rather a metabolic phenotype with altered levels in sugars, amino acids, and ADP contents. Furthermore, coupling of respiration to ATP synthesis is decreased in these lines, while the ADP uptake into mitochondria is significantly increased. Our results indicate that SRT2 is important in fine-tuning mitochondrial energy metabolism

Antithrombotic management and outcomes of patients with atrial fibrillation treated with NOACs early at the time of market introduction:Main results from the PREFER in AF Prolongation Registry

International audienceAbstract The management of patients with atrial fibrillation (AF) has rapidly changed with increasing use of non-vitamin K antagonist oral anticoagulants (NOACs) and changes in the use of rhythm control therapy. The prevention of thromboembolic events European Registry in Atrial Fibrillation Prolongation Registry (PREFER Prolongation) enrolled consecutive patients with AF on NOACs between 2014 and 2016 in a multicentre, prospective, observational study with one-year follow-up, focusing on the time of introduction of NOACs. Overall, 3783 patients were enrolled, with follow-up information available in 3223 (85%). Mean age was 72.2 ± 9.4 years, 40% were women, mean CHA 2 DS 2 VASc score was 3.4 ± 1.6, and 2587 (88.6%) had a CHA 2 DS 2 VASc score ≥ 2. Rivaroxaban was used in half of patients, and dabigatran and apixaban were used in about a quarter of patients each; edoxaban was not available for use in Europe at the time. Major cardiovascular event rate was low: serious events occurred in 74 patients (84 events, 2%), including 24 strokes (1%), 62 major bleeds (2%), of which 30 were life-threatening (1%) and 3 intracranial (0.1%), and 28 acute coronary syndromes (1%). Mortality was 2%. Antiarrhythmic drugs were used in about 50% of patients, catheter ablation in 5%. Adverse events were low in this contemporary European cohort of unselected AF patients treated with NOACs already at the time of their first introduction, despite high thromboembolic risk

Visibility in Information Spaces and in Geographic Environments. Post-Proceedings of the KI'11 Workshop (October 4th, 2011, TU Berlin, Germany)

In the post-proceedings of the Workshop "Visibility in Information Spaces and in Geographic Environments" a selection of research papers is presented where the topic of visibility is addressed in different contexts. Visibility governs information selection in geographic environments as well as in information spaces and in cognition. The users of social media navigate in information spaces and at the same time, as embodied agents, they move in geographic environments. Both activities follow a similar type of information economy in which decisions by individuals or groups require a highly selective filtering to avoid information overload. In this context, visibility refers to the fact that in social processes some actors, topics or places are more salient than others. Formal notions of visibility include the centrality measures from social network analysis or the plethora of web page ranking methods. Recently, comparable approaches have been proposed to analyse activities in geographic environments: Place Rank, for instance, describes the social visibility of urban places based on the temporal sequence of tourist visit patterns. The workshop aimed to bring together researchers from AI, Geographic Information Science, Cognitive Science, and other disciplines who are interested in understanding how the different forms of visibility in information spaces and geographic environments relate to one another and how the results from basic research can be used to improve spatial search engines, geo-recommender systems or location-based social networks