Automated outlier detection with machine learning in GRACE and GRACE-FO post-fit residuals

GRACE/GRACE-FO inter-satellite range-rates are the main observable for the determination of the monthly solutions of the Earthâ?Ts gravity field. The range-rates are sensitive not only to the mass distribution on the Earth, and as a consequence, the relative motion of both GRACE and GRACE-FO satellites, respectively, but also to the relative orientation of the satellites and consequently on the attitude handling, which relies on the star camera observations, object to blinding by sun and moon. In consequence the range-rates observations exhibit a number of difficult to identify error sources and efficient screening is not trivial. We therefore apply novel outlier detection methods such as Isolation Forest and Local Outlier Factor, (collectively known under the term machine learning), to flag outliers in an unsupervised fully automated way. We apply both techniques to the post-fit residuals of monthly, joined orbit and gravity field determination processes, combined with the geographical position of each observation. The flagged outliers are investigated for local geographical correlations to distinguish between unfitted signal from graivitational sources and artefacts caused by the satellite's instrumentation. For that we train a Mutual Information Neural Network, learning the mutual information between the post-fit residuals and the geographical location. The outliers flagged as artefacts are removed from the original inter-satellite range-rate data and orbit and gravity field determination process is repeated to investigate if the gravitational model fits improves

Risk and Timing of Noncardiac Surgery After Transcatheter Aortic Valve Implantation.

Importance Noncardiac surgery after transcatheter aortic valve implantation (TAVI) is a clinical challenge with concerns about safety and optimal management. Objectives To evaluate perioperative risk of adverse events associated with noncardiac surgery after TAVI by timing of surgery, type of surgery, and TAVI valve performance. Design, Setting, and Participants This cohort study was conducted using data from a prospective TAVI registry of patients at the tertiary care University Hospital in Bern, Switzerland. All patients undergoing noncardiac surgery after TAVI were identified. Data were analyzed from November through December 2021. Exposures Timing, clinical urgency, and risk category of noncardiac surgery were assessed among patients who had undergone TAVI and subsequent noncardiac surgery. Main Outcomes and Measures A composite of death, stroke, myocardial infarction, and major or life-threatening bleeding within 30 days after noncardiac surgery. Results Among 2238 patients undergoing TAVI between 2013 and 2020, 300 patients (mean [SD] age, 81.8 [6.6] years; 144 [48.0%] women) underwent elective (160 patients) or urgent (140 patients) noncardiac surgery after TAVI and were included in the analysis. Of these individuals, 63 patients (21.0%) had noncardiac surgery within 30 days of TAVI. Procedures were categorized into low-risk (21 patients), intermediate-risk (190 patients), and high-risk (89 patients) surgery. Composite end points occurred within 30 days of surgery among 58 patients (Kaplan-Meier estimate, 19.7%; 95% CI, 15.6%-24.7%). There were no significant differences in baseline demographics between patients with the 30-day composite end point and 242 patients without this end point, including mean (SD) age (81.3 [7.1] years vs 81.9 [6.5] years; P = .28) and sex (25 [43.1%] women vs 119 [49.2%] women; P = .37). Timing (ie, ≤30 days from TAVI to noncardiac surgery), urgency, and risk category of surgery were not associated with increased risk of the end point. Moderate or severe prosthesis-patient mismatch (adjusted hazard ratio [aHR], 2.33; 95% CI, 1.37-3.95; P = .002) and moderate or severe paravalvular regurgitation (aHR, 3.61; 95% CI 1.25-10.41; P = .02) were independently associated with increased risk of the end point. Conclusions and Relevance These findings suggest that noncardiac surgery may be performed early after successful TAVI. Suboptimal device performance, such as prosthesis-patient mismatch and paravalvular regurgitation, was associated with increased risk of adverse outcomes after noncardiac surgery

Engineered reporter phages for detection of Escherichia coli, Enterococcus, and Klebsiella in urine

The rapid detection and species-level differentiation of bacterial pathogens facilitates antibiotic stewardship and improves disease management. Here, we develop a rapid bacteriophage-based diagnostic assay to detect the most prevalent pathogens causing urinary tract infections: Escherichia coli, Enterococcus spp., and Klebsiella spp. For each uropathogen, two virulent phages were genetically engineered to express a nanoluciferase reporter gene upon host infection. Using 206 patient urine samples, reporter phage-induced bioluminescence was quantified to identify bacteriuria and the assay was benchmarked against conventional urinalysis. Overall, E. coli, Enterococcus spp., and Klebsiella spp. were each detected with high sensitivity (68%, 78%, 87%), specificity (99%, 99%, 99%), and accuracy (90%, 94%, 98%) at a resolution of ≥10$^{3}$ CFU/ml within 5 h. We further demonstrate how bioluminescence in urine can be used to predict phage antibacterial activity, demonstrating the future potential of reporter phages as companion diagnostics that guide patient-phage matching prior to therapeutic phage application

Activation of Neural and Pluripotent Stem Cell Signatures Correlates with Increased Malignancy in Human Glioma

The presence of stem cell characteristics in glioma cells raises the possibility that mechanisms promoting the maintenance and self-renewal of tissue specific stem cells have a similar function in tumor cells. Here we characterized human gliomas of various malignancy grades for the expression of stem cell regulatory proteins. We show that cells in high grade glioma co-express an array of markers defining neural stem cells (NSCs) and that these proteins can fulfill similar functions in tumor cells as in NSCs. However, in contrast to NSCs glioma cells co-express neural proteins together with pluripotent stem cell markers, including the transcription factors Oct4, Sox2, Nanog and Klf4. In line with this finding, in high grade gliomas mesodermal- and endodermal-specific transcription factors were detected together with neural proteins, a combination of lineage markers not normally present in the central nervous system. Persistent presence of pluripotent stem cell traits could only be detected in solid tumors, and observations based on in vitro studies and xenograft transplantations in mice imply that this presence is dependent on the combined activity of intrinsic and extrinsic regulatory cues. Together these results demonstrate a general deregulated expression of neural and pluripotent stem cell traits in malignant human gliomas, and indicate that stem cell regulatory factors may provide significant targets for therapeutic strategies

Full Physics Orbital Simulation around Comet Didymos for CubeSat MissionAPEX on HERA, ESA

We investigate the dynamic environment of the double asteroid system (65803) Didymoswith its satellite Didymos B for stable trajectories of more than 30 days for a model cubesatcalled APEX, foreseen to visit Didymos with the HERA mission, to be launched in 2023.We find semi-stable orbits with lifetimes up to 15 days under the influence of solar radiationpressure. In comparison, in the absence of solar radiation pressure, orbit trajectories reachlifetimes of up to 90 days. We present the distribution of orbital stability for positionsof initial deployment and the related orbital lifetime for inclinations of i = 0, 6 and 30 to the ecliptic plane of the sun, to investigate expected seasonality of the Didymossystem. The influence on trajectories through solar radiation pressure on the arrangementof the solar panels of APEX is compared to trajectories without solar radiation pressure. Itbecomes clear that the influence of solar radiation pressure is the main variable for stabilityof trajectories and must be further investigated with great care. We also discuss briefly theoperation of APEX in relation to orbital corrections and the limitations for such corrections

Planning Observations of Terrestrial ExoplanetsAround M Type Stars with CRIRES+

In recent decades, thousands of exoplanets have been discovered. The next step is to characterize theobserved planets in terms of their radii, masses, density, physical conditions and composition of theiratmospheres. Several space-based observatories such as TESS and CHEOPS have started determiningthe first three observables but characterization of exoplanetary atmospheres is waiting for observationcampaigns with instruments like CRIRES+ at the VLT and NIRSpec on the JWST. To ensure the efficiencyof data acquisition, careful planning of observations is necessary. In this project we developeda software tool to select and rank candidates based on the feasibility of observations of atmosphericfeatures during transits with CRIRES+. We also review different techniques to retrieve transmissionspectra from transit observations and modeling of exoplanet atmospheres in order to clarify the requirementsfor the data. Our CRIRES-planning-tool is built on astronomical observation planningmethods from astropy and astroplan and the exposure time calculator designed for CRIRES+ byESO and UU. We conclude that observations for atmospheric characterization with CRIRES+ are feasible.However, we observed that for a robust candidate selection, careful iterative tuning of proposedconstraints is required

Full Physics Orbital Simulation around Comet Didymos for CubeSat MissionAPEX on HERA, ESA

We investigate the dynamic environment of the double asteroid system (65803) Didymoswith its satellite Didymos B for stable trajectories of more than 30 days for a model cubesatcalled APEX, foreseen to visit Didymos with the HERA mission, to be launched in 2023.We find semi-stable orbits with lifetimes up to 15 days under the influence of solar radiationpressure. In comparison, in the absence of solar radiation pressure, orbit trajectories reachlifetimes of up to 90 days. We present the distribution of orbital stability for positionsof initial deployment and the related orbital lifetime for inclinations of i = 0, 6 and 30 to the ecliptic plane of the sun, to investigate expected seasonality of the Didymossystem. The influence on trajectories through solar radiation pressure on the arrangementof the solar panels of APEX is compared to trajectories without solar radiation pressure. Itbecomes clear that the influence of solar radiation pressure is the main variable for stabilityof trajectories and must be further investigated with great care. We also discuss briefly theoperation of APEX in relation to orbital corrections and the limitations for such corrections

Planning Observations of Terrestrial ExoplanetsAround M Type Stars with CRIRES+

In recent decades, thousands of exoplanets have been discovered. The next step is to characterize theobserved planets in terms of their radii, masses, density, physical conditions and composition of theiratmospheres. Several space-based observatories such as TESS and CHEOPS have started determiningthe first three observables but characterization of exoplanetary atmospheres is waiting for observationcampaigns with instruments like CRIRES+ at the VLT and NIRSpec on the JWST. To ensure the efficiencyof data acquisition, careful planning of observations is necessary. In this project we developeda software tool to select and rank candidates based on the feasibility of observations of atmosphericfeatures during transits with CRIRES+. We also review different techniques to retrieve transmissionspectra from transit observations and modeling of exoplanet atmospheres in order to clarify the requirementsfor the data. Our CRIRES-planning-tool is built on astronomical observation planningmethods from astropy and astroplan and the exposure time calculator designed for CRIRES+ byESO and UU. We conclude that observations for atmospheric characterization with CRIRES+ are feasible.However, we observed that for a robust candidate selection, careful iterative tuning of proposedconstraints is required

Do Service Robots Impair Consumer Fairness Perceptions of a Price Increase?

Service robots are increasingly employed by service providers to greet customers, deliver food, or mix cocktails. While extant research has accumulated some insights on drivers of consumer acceptance, this study adopts a behavioral pricing perspective on the topic. The result of a randomized experiment indicates that consumers perceive a restaurant`s unexpected price increase as less fair if a service robot is present (vs. absent). In contrast to expectations, this effect did not depend on the positioning of the restaurant as price-leader or quality-leader. Price fairness mediated the effect of robot on repurchase intentions, suggesting important implications for pricing

Engineered reporter phages for detection of Escherichia coli, Enterococcus, and Klebsiella in urine

Abstract The rapid detection and species-level differentiation of bacterial pathogens facilitates antibiotic stewardship and improves disease management. Here, we develop a rapid bacteriophage-based diagnostic assay to detect the most prevalent pathogens causing urinary tract infections: Escherichia coli, Enterococcus spp., and Klebsiella spp. For each uropathogen, two virulent phages were genetically engineered to express a nanoluciferase reporter gene upon host infection. Using 206 patient urine samples, reporter phage-induced bioluminescence was quantified to identify bacteriuria and the assay was benchmarked against conventional urinalysis. Overall, E. coli, Enterococcus spp., and Klebsiella spp. were each detected with high sensitivity (68%, 78%, 87%), specificity (99%, 99%, 99%), and accuracy (90%, 94%, 98%) at a resolution of ≥103 CFU/ml within 5 h. We further demonstrate how bioluminescence in urine can be used to predict phage antibacterial activity, demonstrating the future potential of reporter phages as companion diagnostics that guide patient-phage matching prior to therapeutic phage application