| 61. |
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| 62. |
- Abou Ghayda, Ramy, et al.
(författare)
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The global case fatality rate of coronavirus disease 2019 by continents and national income: A meta-analysis
- 2022
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Ingår i: Journal of Medical Virology. - : WILEY. - 0146-6615 .- 1096-9071. ; 94:6, s. 2402-2413
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study is to provide a more accurate representation of COVID-19s case fatality rate (CFR) by performing meta-analyses by continents and income, and by comparing the result with pooled estimates. We used multiple worldwide data sources on COVID-19 for every country reporting COVID-19 cases. On the basis of data, we performed random and fixed meta-analyses for CFR of COVID-19 by continents and income according to each individual calendar date. CFR was estimated based on the different geographical regions and levels of income using three models: pooled estimates, fixed- and random-model. In Asia, all three types of CFR initially remained approximately between 2.0% and 3.0%. In the case of pooled estimates and the fixed model results, CFR increased to 4.0%, by then gradually decreasing, while in the case of random-model, CFR remained under 2.0%. Similarly, in Europe, initially, the two types of CFR peaked at 9.0% and 10.0%, respectively. The random-model results showed an increase near 5.0%. In high-income countries, pooled estimates and fixed-model showed gradually increasing trends with a final pooled estimates and random-model reached about 8.0% and 4.0%, respectively. In middle-income, the pooled estimates and fixed-model have gradually increased reaching up to 4.5%. in low-income countries, CFRs remained similar between 1.5% and 3.0%. Our study emphasizes that COVID-19 CFR is not a fixed or static value. Rather, it is a dynamic estimate that changes with time, population, socioeconomic factors, and the mitigatory efforts of individual countries.
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| 63. |
- Akiyama, Eiji, et al.
(författare)
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SPIRAL STRUCTURE AND DIFFERENTIAL DUST SIZE DISTRIBUTION IN THE LkH alpha 330 DISK
- 2016
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Ingår i: Astronomical Journal. - : American Astronomical Society. - 0004-6256 .- 1538-3881. ; 152:6
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Tidskriftsartikel (refereegranskat)abstract
- Dust trapping accelerates the coagulation of dust particles, and, thus, it represents an initial step toward the formation of planetesimals. We report H-band (1.6 mu m) linear polarimetric observations and 0.87 mm interferometric continuum observations toward a transitional disk around LkH alpha 330. As a. result, a pair of spiral arms were detected in the H-band emission, and an asymmetric (potentially arm-like) structure was detected in the 0.87 mm continuum emission. We discuss the origin of the spiral arm and the asymmetric structure. and suggest that a massive unseen planet is the most plausible explanation. The possibility of dust trapping and grain growth causing the asymmetric structure was also investigated through the opacity index (beta) by plotting the observed spectral energy distribution slope between 0.87 mm from our Submillimeter Array observation and 1.3 mm from literature. The results imply that grains are indistinguishable from interstellar medium-like dust in the east side (beta = 2.0 +/- 0.5) but are much smaller in the west side beta = 0.7(-0.4)(+0.5), indicating differential dust size distribution between the two sides of the disk. Combining the results of near-infrared and submillimeter observations, we conjecture that the spiral arms exist at the upper surface and an asymmetric structure resides in the disk interior. Future observations at centimeter wavelengths and differential polarization imaging in other bands (Y-K) with extreme AO imagers are required to understand how large dust grains form and to further explore the dust distribution in the disk.
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| 64. |
- Alsubai, Khalid, et al.
(författare)
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Qatar Exoplanet Survey : Qatar-3b, Qatar-4b, and Qatar-5b
- 2017
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Ingår i: Astronomical Journal. - : American Astronomical Society. - 0004-6256 .- 1538-3881. ; 153:4
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Tidskriftsartikel (refereegranskat)abstract
- We report the discovery of Qatar-3b, Qatar-4b, and Qatar-5b, three new transiting planets identified by the Qatar Exoplanet Survey. The three planets belong to the hot Jupiter family, with orbital periods of P-Q3b = 2.50792 days, P-Q4b = 1.80539 days, and P-Q5b = 2.87923 days. Follow-up spectroscopic observations reveal the masses of the planets to be M-Q3b = 4.31 +/- 0.47 M-J, M-Q4b = 6.10 +/- 0.54 M-J, and M-Q5b = 4.32 +/- 0.18 M-J, while model fits to the transit light curves yield radii of R-Q3b = 1.096 +/- 0.14 RJ, R-Q4b = 1.135 +/- 0.11 R-J, and R-Q5b = 1.107 +/- 0.064 R-J. The host stars are low-mass main sequence stars with masses and radii M-Q3 = 1.145 +/- 0.064 M circle dot, M-Q4 = 0.896 +/- 0.048 M circle dot, M-Q5 = 1.128 +/- 0.056 M circle dot and R-Q3 = 1.272 +/- 0.14 R circle dot, R-Q4 = 0.849 +/- 0.063 R circle dot, and R-Q5 = 1.076 +/- 0.051 R circle dot for Qatar-3, 4, and 5 respectively. The V magnitudes of the three host stars are V-Q3 = 12.88, V-Q4 = 13.60, and V-Q5 = 12.82. All three new planets can be classified as heavy hot Jupiters (M > 4 M-J).
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| 65. |
- Alzuhairi, Karam Sadoon, et al.
(författare)
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Sub-acute cardiac magnetic resonance to predict irreversible reduction in left ventricular ejection fraction after ST-segment elevation myocardial infarction : A DANAMI-3 sub-study
- 2020
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Ingår i: International Journal of Cardiology. - : Elsevier BV. - 0167-5273. ; 301, s. 215-219
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Tidskriftsartikel (refereegranskat)abstract
- Aims: To predict irreversible reduction in left ventricular ejection fraction (LVEF) during admission for ST-segment elevation myocardial infarction (STEMI) using cardiac magnetic resonance (CMR) in addition to classical clinical parameters. Irreversible reduction in LVEF is an important prognostic factor after STEMI which necessitates medical therapy and implantation of prophylactic implantable cardioverter defibrillator (ICD). Methods and results: A post-hoc analysis of DANAMI-3 trial program (Third DANish Study of Optimal Acute Treatment of Patients With ST-elevation Myocardial Infarction) which recruited 649 patients who had CMR performed during index hospitalization and after 3 months. Patients were divided into two groups according to CMR-LVEF at 3 months: Group 1 with LVEF≤35% and Group 2 with LVEF>35%. Group 1 included 15 patients (2.3%) while Group 2 included 634 patients (97.7%). A multivariate analysis showed that: Killip class >1 (OR 7.39; CI:1.47–36.21, P = 0.01), symptom onset-to-wire ≥6 h (OR 7.19; CI 1.07–50.91, P = 0.04), LVEF≤35% using index echocardiography (OR 7.11; CI: 1.27–47.43, P = 0.03), and infarct size ≥40% of LV on index CMR (OR 42.62; CI:7.83–328.29, P < 0.001) independently correlated with a final LVEF≤35%. Clinical models consisted of these parameters could identify 7 out of 15 patients in Group 1 with 100% positive predictive value. Conclusion: Together with other clinical measurements, the assessment of infarct size using late Gadolinium enhancement by CMR during hospitalization is a strong predictor of irreversible reduction in CMR_LVEF ≤35. That could potentially, after validation with future research, aids the selection and treatment of high-risk patients after STEMI, including implantation of prophylactic ICD during index hospitalization.
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| 66. |
- Bahl, Henning, et al.
(författare)
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HiggsTools : BSM scalar phenomenology with new versions of HiggsBounds and HiggsSignals
- 2023
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Ingår i: Computer Physics Communications. - 0010-4655. ; 291
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Tidskriftsartikel (refereegranskat)abstract
- The codes HiggsBounds and HiggsSignals compare model predictions of BSM models with extended scalar sectors to searches for additional scalars and to measurements of the detected Higgs boson at 125GeV. We present a unification and extension of the functionalities provided by both codes into the new HiggsTools framework. The codes have been re-written in modern C++ with native Python and Mathematica interfaces for easy interactive use. We discuss the user interface for providing model predictions, now part of the new sub-library HiggsPredictions, which also provides access to many cross sections and branching ratios for reference models such as the SM. HiggsBounds now implements experimental limits purely through json data files, can better handle clusters of BSM particles of similar masses (even for complicated search topologies), and features an improved handling of mass uncertainties. Moreover, it now contains an extended list of Higgs-boson pair production searches and doubly-charged Higgs boson searches. In HiggsSignals, the treatment of different types of measurements has been unified, both in the χ2 computation and in the data file format used to implement experimental results. Program summary: Program title: HiggsTools CPC Library link to program files: https://doi.org/10.17632/b25smy28cj.1 Developer's repository link: https://gitlab.com/higgsbounds/higgstools Licensing provisions: GPLv3 Programming language: C++, Python, Mathematica Journal reference of previous version: P. Bechtle, O. Brein, S. Heinemeyer, G. Weiglein, K.E. Williams, Comput. Phys. Commun. 182 (2011), 2605-2631 Does the new version supersede the previous version?: Yes Reasons for the new version: This version extends the functionality of the previous versions and is re-written in modern C++. Summary of revisions: List of included Higgs-boson searches and Higgs-boson rate measurements has been expanded. Nature of problem: Determine whether a parameter point of a given model is excluded or allowed by LEP and LHC Higgs boson search results, and whether this model point is in agreement with the LHC Higgs-boson rate measurements. Solution method: Exclusion by Higgs boson searches: The most sensitive channel from LEP and LHC searches is determined and subsequently applied to test this parameter point for each Higgs boson of the model under consideration. The test requires as input, model predictions for the Higgs boson masses, branching ratios and ratios of production cross sections with respect to reference values. Agreement with LHC Higgs-boson rate measurements: A χ2 value is calculated based on the available LHC rate measurements. This calculation requires as input model predictions for the Higgs boson(s) at ∼125 GeV. Additional comments including restrictions and unusual features: Assumes that the narrow width approximation is applicable in the model under consideration and that the model does not predict a significant change to the signature of the background processes or the kinematical distributions of the signal cross sections.
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| 67. |
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| 68. |
- Barrado, David, et al.
(författare)
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15NH3 in the atmosphere of a cool brown dwarf
- 2023
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Ingår i: Nature. - 0028-0836 .- 1476-4687. ; 624:7991, s. 263-266
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Tidskriftsartikel (refereegranskat)abstract
- Brown dwarfs serve as ideal laboratories for studying the atmospheres of giant exoplanets on wide orbits, as the governing physical and chemical processes within them are nearly identical. Understanding the formation of gas-giant planets is challenging, often involving the endeavour to link atmospheric abundance ratios, such as the carbon-to-oxygen (C/O) ratio, to formation scenarios. However, the complexity of planet formation requires further tracers, as the unambiguous interpretation of the measured C/O ratio is fraught with complexity. Isotope ratios, such as deuterium to hydrogen and 14N/15N, offer a promising avenue to gain further insight into this formation process, mirroring their use within the Solar System. For exoplanets, only a handful of constraints on 12C/13C exist, pointing to the accretion of 13C-rich ice from beyond the CO iceline of the disks. Here we report on the mid-infrared detection of the 14NH3 and 15NH3 isotopologues in the atmosphere of a cool brown dwarf with an effective temperature of 380 K in a spectrum taken with the Mid-Infrared Instrument (MIRI) of JWST. As expected, our results reveal a 14N/15N value consistent with star-like formation by gravitational collapse, demonstrating that this ratio can be accurately constrained. Because young stars and their planets should be more strongly enriched in the 15N isotope, we expect that 15NH3 will be detectable in several cold, wide-separation exoplanets.
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| 69. |
- Baturova, Maria A., et al.
(författare)
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Atrial fibrillation as a clinical characteristic of arrhythmogenic right ventricular cardiomyopathy : Experience from the Nordic ARVC Registry
- 2020
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Ingår i: International Journal of Cardiology. - : Elsevier BV. - 0167-5273 .- 1874-1754. ; 298, s. 39-43
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Tidskriftsartikel (refereegranskat)abstract
- Background: Recent studies in arrhythmogenic right ventricular cardiomyopathy (ARVC) patients have drawn attention to atrial fibrillation (AF) as an arrhythmic manifestation of ARVC and as an indicator of atrial involvement in the disease progression. We aimed to assess the prevalence of AF in the Scandinavian cohort of ARVC patients and to evaluate its association with disease clinical manifestations. Methods: Study sample comprised of 293 definite ARVC patients by 2010 Task Force criteria (TFC2010) and 141 genotype-positive family members (total n = 434, 43% females, median age at ARVC diagnosis 41 years [interquartile range (IQR) 28–52 years]). ARVC diagnostic score was calculated as the sum of major (2 points) and minor (1 point) criteria in all categories of the TFC2010. Results: AF was diagnosed in 42 patients (10%): in 41 patients with definite ARVC diagnosis (14%) vs in one genotype-positive family member (1%), p < 0.001. The median age at AF onset was 51 (IQR 38–58) years. The prevalence of AF was related to the ARVC diagnostic score: it significantly increased starting with the diagnostic score 4 (2% in those with score 3 vs 13% in those with score 4, p = 0.023) and increased further with increased diagnostic score (Somer's d value is 0.074, p < 0.001). Conclusion: AF is seen in 14% of definite ARVC patients and is related to the severity of disease phenotype thus suggesting AF being an arrhythmic manifestation of this cardiomyopathy indicating atrial myocardial involvement in the disease progression.
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| 70. |
- Bera, Soumya, et al.
(författare)
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One-particle density matrix characterization of many-body localization
- 2017
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Ingår i: Annalen der Physik. - : Wiley-VCH Verlagsgesellschaft. - 0003-3804 .- 1521-3889. ; 529:7
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Tidskriftsartikel (refereegranskat)abstract
- We study interacting fermions in one dimension subject to random, uncorrelated onsite disorder, a paradigmatic model of many-body localization (MBL). This model realizes an interaction-driven quantum phase transition between an ergodic and a many-body localized phase, with the transition occurring in the many-body eigenstates. We propose a single-particle framework to characterize these phases by the eigenstates (the natural orbitals) and the eigenvalues (the occupation spectrum) of the one-particle density matrix (OPDM) in individual many-body eigenstates. As a main result, we find that the natural orbitals are localized in the MBL phase, but delocalized in the ergodic phase. This qualitative change in these single-particle states is a many-body effect, since without interactions the single-particle energy eigenstates are all localized. The occupation spectrum in the ergodic phase is thermal in agreement with the eigenstate thermalization hypothesis, while in the MBL phase the occupations preserve a discontinuity at an emergent Fermi edge. This suggests that the MBL eigenstates are weakly dressed Slater determinants, with the eigenstates of the underlying Anderson problem as reference states. We discuss the statistical properties of the natural orbitals and of the occupation spectrum in the two phases and as the transition is approached. Our results are consistent with the existing picture of emergent integrability and localized integrals of motion, or quasiparticles, in the MBL phase. We emphasize the close analogy of the MBL phase to a zero-temperature Fermi liquid: in the studied model, the MBL phase is adiabatically connected to the Anderson insulator and the occupation-spectrum discontinuity directly indicates the presence of quasiparticles localized in real space. Finally, we show that the same picture emerges for interacting fermions in the presence of an experimentally-relevant bichromatic lattice and thereby demonstrate that our findings are not limited to a specific model.
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