Minimal connected enclosures on an embedded planar graph

We study five problems of finding minimal enclosures comprised of elements of a connected, planar graph with a plane embedding. The first three problems consider the identification of a shortest enclosing walk, cycle or trail surrounding a polygonal, simply connected obstacle on the plane. We propose polynomial algorithms that improve on existing algorithms. The last two problems consider the formation of minimal zones (sets of adjacent regions such that any pair of points in a zone can be connected by a non-zero width curve that lies entirely in the zone). Specifically, we assume that the regions of the graph have nonnegative weights and seek the formation of minimum weight zones containing a set of points or a set of regions. We prove that the last two problems are NP-hard and transform them to Steiner arboresccnce/fixed-charge flow problems

Detecting anomalies in heterogeneous population-scale VAT networks

Anomaly detection in network science is the method to determine aberrant edges, nodes, subgraphs or other network events. Heterogeneous networks typically contain information going beyond the observed network itself. Value Added Tax (VAT, a tax on goods and services) networks, defined from pairwise interactions of VAT registered taxpayers, are analysed at a population-scale requiring scalable algorithms. By adopting a quantitative understanding of the nature of VAT-anomalies, we define a method that identifies them utilising information from micro-scale, meso-scale and global-scale patterns that can be interpreted, and efficiently implemented, as population-scale network analysis. The proposed method is automatable, and implementable in real time, enabling revenue authorities to prevent large losses of tax revenues through performing early identification of fraud within the VAT system.Comment: 14 pages, 5 figures, 3 table

Antithrombotics in Complex Percutaneous Coronary Interventions: Type and Duration of Treatment

Patients undergoing complex percutaneous coronary intervention (PCI) are at an increased risk of atherothrombotic complications. Although dual antiplatelet therapy is the mainstay of treatment for patients undergoing PCI with stent implantation, deciding its type and duration in complex PCI patients has long been considered a challenge for clinicians. This is because the beneficial effects of prolonged treatment and/or more potent antiplatelet agents’ use in preventing ischemic events are hindered by a concomitant increase in bleeding complications. The aim of this review is to highlight current evidence regarding the optimal antithrombotic therapy regimens used in complex PCI patients, focusing on the evaluation of both safety and efficacy outcomes as well as addressing future perspectives

Perceived Stress Scale: Reliability and Validity Study in Greece

Objective: To translate the Perceived Stress Scale (versions PSS-4, -10 and -14) and to assess its psychometric properties in a sample of general Greek population. Methods: 941 individuals completed anonymously questionnaires comprising of PSS, the Depression Anxiety and Stress scale (DASS-21 version), and a list of stress-related symptoms. Psychometric properties of PSS were investigated by confirmatory factor analysis (construct validity), Cronbach’s alpha (reliability), and by investigating relations with the DASS-21 scores and the number of symptoms, across individuals’ characteristics. The two-factor structure of PSS-10 and PSS-14 was confirmed in our analysis. We found satisfactory Cronbach’s alpha values (0.82 for the full scale) for PSS-14 and PSS-10 and marginal satisfactory values for PSS-4 (0.69). PSS score exhibited high correlation coefficients with DASS-21 subscales scores, meaning stress (r = 0.64), depression (r = 0.61), and anxiety (r = 0.54). Women reported significantly more stress compared to men and divorced or widows compared to married or singled only. A strong significant (p < 0.001) positive correlation between the stress score and the number of self-reported symptoms was also noted. Conclusions: The Greek versions of the PSS-14 and PSS-10 exhibited satisfactory psychometric properties and their use for research and health care practice is warranted

An analysis of factors that influence personal exposure to toluene and xylene in residents of Athens, Greece

BACKGROUND: Personal exposure to pollutants is influenced by various outdoor and indoor sources. The aim of this study was to evaluate the exposure of Athens citizens to toluene and xylene, excluding exposure from active smoking. METHODS: Passive air samplers were used to monitor volunteers, their homes and various urban sites for one year, resulting in 2400 measurements of toluene and xylene levels. Since both indoor and outdoor pollution contribute significantly to human exposure, volunteers were chosen from occupational groups who spend a lot of time in the streets (traffic policemen, bus drivers and postmen), and from groups who spend more time indoors (teachers and students). Data on individual and house characteristics were obtained using a questionnaire completed at the beginning of the study; a time-location-activity diary was also completed daily by the volunteers in each of the six monitoring campaigns. RESULTS: Average personal toluene exposure varied over the six monitoring campaigns from 53 to 80 μg/m(3). Urban and indoor concentrations ranged from 47 – 84 μg/m(3 )and 30 – 51 μg/m(3), respectively. Average personal xylene exposure varied between 56 and 85 μg/m(3 )while urban and indoor concentrations ranged from 53 – 88 μg/m(3 )and 27 – 48 μg/m(3), respectively. Urban pollution, indoor residential concentrations and personal exposures exhibited the same pattern of variation during the measurement periods. This variation among monitoring campaigns might largely be explained by differences in climate parameters, namely wind speed, humidity and amount of sunlight. CONCLUSION: In Athens, Greece, the time spent outdoors in the city center during work or leisure makes a major contribution to exposure to toluene and xylene among non-smoking citizens. Indoor pollution and means of transportation contribute significantly to individual exposure levels. Other indoor residential characteristics such as recent painting and mode of heating used might also contribute significantly to individual levels. Groups who may be subject to higher exposures (e.g. those who spent more time outdoors because of occupational activities) need to be surveyed and protected against possible adverse health effects

Crowdsourced mapping of unexplored target space of kinase inhibitors

Despite decades of intensive search for compounds that modulate the activity of particular protein targets, a large proportion of the human kinome remains as yet undrugged. Effective approaches are therefore required to map the massive space of unexplored compound-kinase interactions for novel and potent activities. Here, we carry out a crowdsourced benchmarking of predictive algorithms for kinase inhibitor potencies across multiple kinase families tested on unpublished bioactivity data. We find the top-performing predictions are based on various models, including kernel learning, gradient boosting and deep learning, and their ensemble leads to a predictive accuracy exceeding that of single-dose kinase activity assays. We design experiments based on the model predictions and identify unexpected activities even for under-studied kinases, thereby accelerating experimental mapping efforts. The open-source prediction algorithms together with the bioactivities between 95 compounds and 295 kinases provide a resource for benchmarking prediction algorithms and for extending the druggable kinome. The IDG-DREAM Challenge carried out crowdsourced benchmarking of predictive algorithms for kinase inhibitor activities on unpublished data. This study provides a resource to compare emerging algorithms and prioritize new kinase activities to accelerate drug discovery and repurposing efforts

Impact of chronic obstructive pulmonary disease on short-term outcome in patients with ST-elevation myocardial infarction during COVID-19 pandemic: insights from the international multicenter ISACS-STEMI registry

Background Chronic obstructive pulmonary disease (COPD) is projected to become the third cause of mortality worldwide. COPD shares several pathophysiological mechanisms with cardiovascular disease, especially atherosclerosis. However, no definite answers are available on the prognostic role of COPD in the setting of ST elevation myocardial infarction (STEMI), especially during COVID-19 pandemic, among patients undergoing primary angioplasty, that is therefore the aim of the current study. Methods In the ISACS-STEMI COVID-19 registry we included retrospectively patients with STEMI treated with primary percutaneous coronary intervention (PCI) between March and June of 2019 and 2020 from 109 high-volume primary PCI centers in 4 continents. Results A total of 15,686 patients were included in this analysis. Of them, 810 (5.2%) subjects had a COPD diagnosis. They were more often elderly and with a more pronounced cardiovascular risk profile. No preminent procedural dissimilarities were noticed except for a lower proportion of dual antiplatelet therapy at discharge among COPD patients (98.9% vs. 98.1%, P = 0.038). With regards to short-term fatal outcomes, both in-hospital and 30-days mortality occurred more frequently among COPD patients, similarly in pre-COVID-19 and COVID-19 era. However, after adjustment for main baseline differences, COPD did not result as independent predictor for in-hospital death (adjusted OR [95% CI] = 0.913[0.658-1.266], P = 0.585) nor for 30-days mortality (adjusted OR [95% CI] = 0.850 [0.620-1.164], P = 0.310). No significant differences were detected in terms of SARS-CoV-2 positivity between the two groups. Conclusion This is one of the largest studies investigating characteristics and outcome of COPD patients with STEMI undergoing primary angioplasty, especially during COVID pandemic. COPD was associated with significantly higher rates of in-hospital and 30-days mortality. However, this association disappeared after adjustment for baseline characteristics. Furthermore, COPD did not significantly affect SARS-CoV-2 positivity. Trial registration number: NCT 04412655 (2nd June 2020)

Study of ordered hadron chains with the ATLAS detector

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A search for resonances decaying into a Higgs boson and a new particle X in the XH→qqbb final state with the ATLAS detector

A search for heavy resonances decaying into a Higgs boson ($H$) and a new particle ($X$) is reported, utilizing 36.1 fb$^{-1}$ of proton-proton collision data at $\sqrt{s} =$ 13 TeV collected during 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. The particle $X$ is assumed to decay to a pair of light quarks, and the fully hadronic final state $XH \rightarrow q\bar q'b\bar b$ is analysed. The search considers the regime of high $XH$ resonance masses, where the $X$ and $H$ bosons are both highly Lorentz-boosted and are each reconstructed using a single jet with large radius parameter. A two-dimensional phase space of $XH$ mass versus $X$ mass is scanned for evidence of a signal, over a range of $XH$ resonance mass values between 1 TeV and 4 TeV, and for $X$ particles with masses from 50 GeV to 1000 GeV. All search results are consistent with the expectations for the background due to Standard Model processes, and 95% CL upper limits are set, as a function of $XH$ and $X$ masses, on the production cross-section of the $XH\rightarrow q\bar q'b\bar b$ resonance

Search for dark matter produced in association with bottom or top quarks in √s = 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 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 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