The diffuse ionized gas (DIG) in star-forming galaxies: the influence of aperture effects on local H ii regions

ABSTRACT The diffuse ionized gas (DIG) contributes to the nebular emission of galaxies, resulting in emission line flux ratios that can be significantly different from those produced by H ii regions. Comparing the emission of [SII]λ6717,31 between pointed observations of H ii regions in nearby galaxies and integrated spectra of more distant galaxies, it has been recently claimed that the DIG can also deeply affect the emission of bright, star-forming galaxies, and that a large correction must be applied to observed line ratios to recover the genuine contribution from H ii regions. Here, we show instead that the e?ect of DIG on the integrated spectra of star-forming galaxies is lower than assumed in previous work. Here we show that, in contrast, aperture effects on the spectroscopy of nearby H ii regions are largely responsible for the observed difference: When spectra of local H ii regions are extracted using large enough apertures while still avoiding the DIG, the observed line ratios are the same as in more distant galaxies. This result is highly relevant for the use of strong-line methods to measure metallicity.

Strong CP problem and axion dark matter with small instantons

The axion mass receives a large correction from small instantons if the QCD gets strongly coupled at high energies. We discuss the size of the new CP violating phases caused by the fact that the small instantons are sensitive to the UV physics. We also discuss the effects of the mass correction on the axion abundance of the Universe. Taking the small-instanton contributions into account, we propose a natural scenario of axion dark matter where the axion decay constant is as large as 1015-16 GeV. The scenario works in the high-scale inflation models.

Opening Wedge Tibial Osteotomy in Medial Osteoarthritis of Varus Knee: Is it Necessary to Graft?

Background: Opening wedge high tibial osteotomy (OWHTO) is accepted and commonly used procedure in selected patients with medial osteoathrosis in the varus knee. The aim of this study is to demonstrate that OWHTO can be performed without graft interposition to filling the osteotomy defect and we evaluate bone union, its complications (delayed or nonunion), and functional results. Materials and Methods: This is a continuous retrospective study of patients treated by OWHTO from July 2008 to August 2018. OWHTO was performed using a 4 holes wedges-plate of Puddu without interposition of graft. HKA angle was assessed preoperatively and postoperatively and at 3 months. Clinical and radiological follow-up at 6 weeks, 3 months and 6 months assessed consolidation in terms of filing the defect of the osteotomy according to the method recommended by Brosset. Results: Mean age was 53.2 years. Mean body mass index was 24, 8 and 30% of patients had BMI >30. The average varus was 171° (165°-177°); postoperatively, the HKA angle was 182° (176°-186°). Radiological union occurred on average after 3.5 months, with a minimum of 2 months and a maximum of 5. The time to union was 3.7 months for opening wedges of more than 10° and 3.4 months for opening wedges of 10° or less. 9 patients showed delayed union; in all these cases the lateral cortex was broken initially (stage II Takeuchi) with large correction>10°, 4 of them had BMI>30. The IKS knee score increased from 69 to 90 and the functional score increased 84 to 95 with 95% of patients scoring between 92 and 97. Conclusion: OWHTO without graft interposition using a wedges plate can be considered an alternative in the treatment of medial osteoarthritis of the varus knee, enabling the correction of the deformity and improvement of the clinical picture. Precautions must be taken event of large correction>10° and unstable lateral cortex fracture (stage II Takeuchi).

Analysis of the time and age dependence of the case-fatality-ratio for COVID-19 in seven countries with a high total-to-positive test ratio suggests that the true CFR may be significantly underestimated for the United States in current models

Background. Knowing the true infected and symptomatic case fatality ratios (IFR and CFR) for COVID-19 is of high importance for epidemiological model projections. A large correction factor is usually applied for missed cases. For the United State reported CFR of 5.96%, the estimated IFR values are 10-50-fold lower, justified by early reported CFR values of 0.1% to 0.5% in countries with more extensive testing. However, since then these values have risen 5 to 10-fold. We analyzed their age dependent CFR time courses to explain this increase and to determine whether a common factor can explain their CFRs. Methods. Age dependent time to fatality corrected CFR was calculated using two independent methods. A linear model was developed that predicts CFR based on age dependent CFR coefficients and the age distribution of cases. The model was tested by a linear regression of each country's CFR against case percentage of 70 years and over. The model was further tested by calculating the percent of the population in New York City who have been infected. Results. Corrected CFR values ranged from 0.58% to 5.0%. The large majority of CFR variation was explained by case age distribution above 70 years old. Using the CFR derived from the linear model we predicted between 14.7% and 22% of the adult population in NYC had been infected by COVID-19, in agreement with random testing studies (15.3% - 21%). Conclusions. The large rise in the reported CFR is due to the delay time between infection/diagnosis and fatality with COVID-19. The linear model based on their age specific CFR values provides an alternative method for calculating the true CFR in other regions. Most of the variation in CFR between countries was dependent on case age distribution, which must be considered in measures for mitigating the extensive impacts of the pandemic.

Correcting spaceborne reflectivity measurements for application in solar ultraviolet radiation levels calculations at ground level

The Lambertian Equivalent Reflection (LER) produced by satellite-carried instruments is used to determine cloud effects on ground level UltraViolet (UV) radiation. The focus is on data use from consecutive operating instruments: the Total Ozone Mapping Spectrometers (TOMS) flown on Nimbus 7 from 1979 to 1992, TOMS on Earth Probe from 1996 to 2005, and the Ozone Monitoring Instrument (OMI) flown on Aura since 2004. The LER data produced by TOMS on Earth Probe is only included until 2002. The possibility to use the Radiative Cloud Fraction (RCF)-product of OMI is also investigated. A comparison is made with cloud effects inferred from ground-based pyranometer measurements at over 83 World Radiation Data Centre stations. Modelled UV irradiances utilizing LER data are compared with measurements of UV irradiances at eight European low elevation stations. The LER data set of the two TOMS instruments shows a consistent agreement, and the required corrections are of low percentage i.e. 2–3%. In contrast, the LER data of OMI requires correction of 7–10%, and a solar angle dependency therein is more pronounced. These corrections were inferred from a comparison with pyranometer data, and tested using the UV measurements. The RCF product of OMI requires a large correction but can then be implemented as a cloud effect proxy. However, a major drawback of RCF is the large number of clipped data, i.e. 18%, and results are not better than those obtained with the corrected LER product of OMI. The average reduction of UV radiation due to clouds for all sites together indicate a small trend: a diminishing cloudiness, in line with ground-based UV observations. Uncorrected implementation of LER would have indicated the opposite. An optimal field of view of 1.25° was established for LER data to calculate UV radiations levels. The corresponding area can be traversed within 5–7 h at the average wind speeds found for the West European continent.

Reduced Complexity Iterative Decoding of 3D-Product Block Codes Based on Genetic Algorithms

Two iterative decoding algorithms of 3D-product block codes (3D-PBC) based on genetic algorithms (GAs) are presented. The first algorithm uses the Chase-PyndiahSISO, and the second one uses the list-basedSISOdecoding algorithm (LBDA) based on order- reprocessing. We applied these algorithms overAWGNchannel to symmetric3D-PBCconstructed fromBCHcodes. The simulation results show that the first algorithm outperforms the Chase-Pyndiah one and is only 1.38 dB away from the Shannon capacity limit at BER of forBCH(31, 21, 5)3and 1.4 dB forBCH(16, 11, 4)3. The simulations of the LBDA-basedGAon theBCH(16, 11, 4)3show that its performances outperform the first algorithm and is about 1.33 dB from the Shannon limit. Furthermore, these algorithms can be applied to any arbitrary 3D binary product block codes, without the need of a hard-in hard-out decoder. We show also that the two proposed decoders are less complex than both Chase-Pyndiah algorithm for codes with large correction capacity and LBDA for large parameter. Those features make the decoders based on genetic algorithms efficient and attractive.

SPIN POLARIZABILITY OF THE NUCLEON IN THE EFFECTIVE FIELD THEORY OF HEAVY BARYON

We have constructed a heavy baryon effective field theory with photon as an external field in accordance with the symmetry requirements similar to the heavy quark effective field theory. By treating the heavy baryon and antibaryon equally on the same footing in the effective field theory, we have calculated the spin polarizabilities γi, i = 1,…,4 of the nucleon at third order and at fourth-order of the spin-dependent Compton scattering. At leading order (LO), our results agree with the corresponding results of the heavy baryon chiral perturbation theory, at the next-to-leading order (NLO) the results show a large correction to the ones in the heavy baryon chiral perturbation theory due to baryon–antibaryon coupling terms. The low-energy theorem is satisfied both at LO and at NLO. The contributions arising from the heavy baryon–antibaryon vertex were found to be significant and the results of the polarizabilities obtained from our theory is much closer to the experimental data.

RADIATIVE CORRECTIONS TO $e^ + e^ - \to \bar tt$ IN ELECTROWEAK THEORY

The 0(α) radiative corrections to [Formula: see text] are calculated in the standard SU(2)×U(1) theory keeping the top quark mass. The contribution of the hard photon emission is included with suitable experimental cuts. We found that the 1-loop vertex diagrams for the top quark give rise to a fairly large correction in the order of 5% to the differential cross-section. Effects of the Higgs boson exchange are also discussed.