19 research outputs found

    A catalogue of structural and morphological measurements for DES Y1

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    We present a structural and morphological catalogue for 45 million objects selected from the first year data of the Dark Energy Survey (DES). Single S´ersic fits and non-parametric measurements are produced for g, r, and i filters. The parameters from the best-fitting S´ersic model (total magnitude, half-light radius, S´ersic index, axis ratio, and position angle) are measured with GALFIT; the non-parametric coefficients (concentration, asymmetry, clumpiness, Gini, M20) are provided using the Zurich Estimator of Structural Types (ZEST+). To study the statistical uncertainties, we consider a sample of state-of-the-art image simulations with a realistic distribution in the input parameter space and then process and analyse them as we do with real data: this enables us to quantify the observational biases due to PSF blurring and magnitude effects and correct themeasurements as a function ofmagnitude, galaxy size, S´ersic index (concentration for the analysis of the non-parametric measurements) and ellipticity. We present the largest structural catalogue to date: we find that accurate and complete measurements for all the structural parameters are typically obtained for galaxies with SEXTRACTOR MAG AUTO I ≤ 21. Indeed, the parameters in the filters i and r can be overall well recovered up to MAG AUTO ≤ 21.5, corresponding to a fitting completeness of ~90 per cent below this threshold, for a total of 25million galaxies. The combination of parametric and non-parametric structural measurements makes this catalogue an important instrument to explore and understand how galaxies form and evolve. The catalogue described in this paper will be publicly released alongside the DES collaboration Y1 cosmology data products at the following URL: https://des.ncsa.illinois.edu/releases

    Symbolic Implementation of Extensions of the PyCosmo\texttt{PyCosmo} Boltzmann Solver

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    PyCosmo\texttt{PyCosmo} is a Python-based framework for the fast computation of cosmological model predictions. One of its core features is the symbolic representation of the Einstein-Boltzmann system of equations. Efficient C/C++\texttt{C/C++} code is generated from the SymPy\texttt{SymPy} symbolic expressions making use of the sympy2c\texttt{sympy2c} package. This enables easy extensions of the equation system for the implementation of new cosmological models. We illustrate this with three extensions of the PyCosmo\texttt{PyCosmo} Boltzmann solver to include a dark energy component with a constant equation of state, massive neutrinos and a radiation streaming approximation. We describe the PyCosmo\texttt{PyCosmo} framework, highlighting new features, and the symbolic implementation of the new models. We compare the PyCosmo\texttt{PyCosmo} predictions for the Λ\LambdaCDM model extensions with CLASS\texttt{CLASS}, both in terms of accuracy and computational speed. We find a good agreement, to better than 0.1% when using high-precision settings and a comparable computational speed. Links to the Python Package Index (PyPI) page of the code release and to the PyCosmo Hub, an online platform where the package is installed, are available at: https://cosmology.ethz.ch/research/software-lab/PyCosmo.html.Comment: 35 pages including 5 figures and 3 tables. Link to PyCosmo\texttt{PyCosmo} package: https://cosmology.ethz.ch/research/software-lab/PyCosmo.htm

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    A catalogue of structural and morphological measurements for DES Y1

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    We present a structural and morphological catalogue for 45 million objects selected from the first year data of the Dark Energy Survey (DES). Single S´ersic fits and non-parametric measurements are produced for g, r, and i filters. The parameters from the best-fitting S´ersic model (total magnitude, half-light radius, S´ersic index, axis ratio, and position angle) are measured with GALFIT; the non-parametric coefficients (concentration, asymmetry, clumpiness, Gini, M20) are provided using the Zurich Estimator of Structural Types (ZEST+). To study the statistical uncertainties, we consider a sample of state-of-the-art image simulations with a realistic distribution in the input parameter space and then process and analyse them as we do with real data: this enables us to quantify the observational biases due to PSF blurring and magnitude effects and correct themeasurements as a function ofmagnitude, galaxy size, S´ersic index (concentration for the analysis of the non-parametric measurements) and ellipticity. We present the largest structural catalogue to date: we find that accurate and complete measurements for all the structural parameters are typically obtained for galaxies with SEXTRACTOR MAG AUTO I ≤ 21. Indeed, the parameters in the filters i and r can be overall well recovered up to MAG AUTO ≤ 21.5, corresponding to a fitting completeness of ~90 per cent below this threshold, for a total of 25million galaxies. The combination of parametric and non-parametric structural measurements makes this catalogue an important instrument to explore and understand how galaxies form and evolve. The catalogue described in this paper will be publicly released alongside the DES collaboration Y1 cosmology data products at the following URL: https://des.ncsa.illinois.edu/releases

    Assessing theoretical uncertainties for cosmological constraints from weak lensing surveys

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    Weak gravitational lensing is a powerful probe which is used to constrain the standard cosmological model and its extensions. With the enhanced statistical precision of current and upcoming surveys, high accuracy predictions for weak lensing statistics are needed to limit the impact of theoretical uncertainties on cosmological parameter constraints. For this purpose, we present a comparison of the theoretical predictions for the nonlinear matter and weak lensing power spectra, based on the widely used fitting functions (mead\texttt{mead} and rev-halofit\texttt{rev-halofit}), emulators (EuclidEmulator\texttt{EuclidEmulator}, EuclidEmulator2\texttt{EuclidEmulator2}, BaccoEmulator\texttt{BaccoEmulator} and CosmicEmulator\texttt{CosmicEmulator}) and N-body simulations (Pkdgrav3\texttt{Pkdgrav3}). We consider the forecasted constraints on the ΛCDM\Lambda \texttt{CDM} and wCDM\texttt{wCDM} models from weak lensing for stage III and stage IV surveys. We study the relative bias on the constraints and their dependence on the assumed prescriptions. Assuming a ΛCDM\Lambda \texttt{CDM} cosmology, we find that the relative agreement on the S8S_8 parameter is between 0.20.3σ0.2-0.3\sigma for a stage III-like survey between the above predictors. For a stage IV-like survey the agreement becomes 1.43.0σ1.4-3.0\sigma. In the wCDM\texttt{wCDM} scenario, we find broader S8S_8 constraints, and agreements of 0.180.26σ0.18-0.26\sigma and 0.71.7σ0.7-1.7\sigma for stage III and stage IV surveys, respectively. The accuracies of the above predictors therefore appear adequate for stage III surveys, while the fitting functions would need improvements for future stage IV weak lensing surveys. Furthermore, we find that, of the fitting functions, mead\texttt{mead} provides the best agreement with the emulators. We discuss the implication of these findings for the preparation of the future weak lensing surveys.Comment: 18 pages, 10 figure

    Assessing theoretical uncertainties for cosmological constraints from weak lensing surveys

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    Weak gravitational lensing is a powerful probe which is used to constrain the standard cosmological model and its extensions. With the enhanced statistical precision of current and upcoming surveys, high accuracy predictions for weak lensing statistics are needed to limit the impact of theoretical uncertainties on cosmological parameter constraints. For this purpose, we present a comparison of the theoretical predictions for the nonlinear matter and weak lensing power spectra, based on the widely used fitting functions (mead\texttt{mead} and rev-halofit\texttt{rev-halofit}), emulators (EuclidEmulator\texttt{EuclidEmulator}, EuclidEmulator2\texttt{EuclidEmulator2}, BaccoEmulator\texttt{BaccoEmulator} and CosmicEmulator\texttt{CosmicEmulator}) and N-body simulations (Pkdgrav3\texttt{Pkdgrav3}). We consider the forecasted constraints on the ΛCDM\Lambda \texttt{CDM} and wCDM\texttt{wCDM} models from weak lensing for stage III and stage IV surveys. We study the relative bias on the constraints and their dependence on the assumed prescriptions. Assuming a ΛCDM\Lambda \texttt{CDM} cosmology, we find that the relative agreement on the S8S_8 parameter is between 0.20.3σ0.2-0.3\sigma for a stage III-like survey between the above predictors. For a stage IV-like survey the agreement becomes 1.43.0σ1.4-3.0\sigma. In the wCDM\texttt{wCDM} scenario, we find broader S8S_8 constraints, and agreements of 0.180.26σ0.18-0.26\sigma and 0.71.7σ0.7-1.7\sigma for stage III and stage IV surveys, respectively. The accuracies of the above predictors therefore appear adequate for stage III surveys, while the fitting functions would need improvements for future stage IV weak lensing surveys. Furthermore, we find that, of the fitting functions, mead\texttt{mead} provides the best agreement with the emulators. We discuss the implication of these findings for the preparation of the future weak lensing surveys

    Assessing theoretical uncertainties for cosmological constraints from weak lensing surveys

    No full text
    Weak gravitational lensing is a powerful probe, which is used to constrain the standard cosmological model and its extensions. With the enhanced statistical precision of current and upcoming surveys, high-accuracy predictions for weak lensing statistics are needed to limit the impact of theoretical uncertainties on cosmological parameter constraints. For this purpose, we present a comparison of the theoretical predictions for the non-linear matter and weak lensing power spectra, based on the widely used fitting functions (mead and rev-halofit), emulators (EuclidEmulator, EuclidEmulator2, BaccoEmulator, and CosmicEmulator), and N-body simulations (PKDGRAV3). We consider the forecasted constraints on the ЛCDM and wCDM models from weak lensing for stage III and stage IV surveys. We study the relative bias on the constraints and their dependence on the assumed prescriptions. Assuming a ЛCDM cosmology, we find that the relative agreement on the S8 parameter is between 0.2 and 0.3σ for a stage III-like survey between the above predictors. For a stage IV-like survey the agreement becomes 1.4-3.0σ. In the wCDM scenario, we find broader S8 constraints, and agreements of 0.18-0.26σ and 0.7-1.7σ for stage III and stage IV surveys, respectively. The accuracies of the above predictors therefore appear adequate for stage III surveys, whereas the fitting functions would need improvements for future stage IV surveys. Furthermore, we find that, of the fitting functions, mead provides the best agreement with the emulators. We discuss the implication of these findings for the preparation of future weak lensing surveys, and the relative impact of theoretical uncertainties to other systematics.ISSN:0035-8711ISSN:1365-296

    Preclinical Application of Augmented Reality in Pediatric Craniofacial Surgery: An Accuracy Study

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    Background: Augmented reality (AR) allows the overlapping and integration of virtual information with the real environment. The camera of the AR device reads the object and integrates the virtual data. It has been widely applied to medical and surgical sciences in recent years and has the potential to enhance intraoperative navigation. Materials and methods: In this study, the authors aim to assess the accuracy of AR guidance when using the commercial HoloLens 2 head-mounted display (HMD) in pediatric craniofacial surgery. The Authors selected fronto-orbital remodeling (FOR) as the procedure to test (specifically, frontal osteotomy and nasal osteotomy were considered). Six people (three surgeons and three engineers) were recruited to perform the osteotomies on a 3D printed stereolithographic model under the guidance of AR. By means of calibrated CAD/CAM cutting guides with different grooves, the authors measured the accuracy of the osteotomies that were performed. We tested accuracy levels of ±1.5 mm, ±1 mm, and ±0.5 mm. Results: With the HoloLens 2, the majority of the individuals involved were able to successfully trace the trajectories of the frontal and nasal osteotomies with an accuracy level of ±1.5 mm. Additionally, 80% were able to achieve an accuracy level of ±1 mm when performing a nasal osteotomy, and 52% were able to achieve an accuracy level of ±1 mm when performing a frontal osteotomy, while 61% were able to achieve an accuracy level of ±0.5 mm when performing a nasal osteotomy, and 33% were able to achieve an accuracy level of ±0.5 mm when performing a frontal osteotomy. Conclusions: despite this being an in vitro study, the authors reported encouraging results for the prospective use of AR on actual patients
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