CHIANTI contains a large quantity of atomic data for the analysis of astrophysical spectra. Programs are available in IDL and Python to perform calculation of the expected emergent spectrum from ...these sources. The database includes atomic energy levels, wavelengths, radiative transition probabilities, rate coefficients for collisional excitation, ionization, and recombination, as well as data to calculate free-free, free-bound, and two-photon continuum emission. In Version 9, we improve the modeling of the satellite lines at X-ray wavelengths by explicitly including autoionization and dielectronic recombination processes in the calculation of level populations for select members of the lithium isoelectronic sequence and Fe xviii-xxiii. In addition, existing data sets are updated, new ions are added, and new total recombination rates for several Fe ions are included. All data and IDL programs are freely available at http://www.chiantidatabase.org or through SolarSoft, and the Python code ChiantiPy is also freely available at https://github.com/chianti-atomic/ChiantiPy.
The density variance–Mach number relation of the turbulent interstellar medium is relevant for theoretical models of the star formation rate, efficiency, and the initial mass function of stars. Here ...we use high-resolution hydrodynamical simulations with grid resolutions of up to 10243 cells to model compressible turbulence in a regime similar to the observed interstellar medium. We use fyris alpha, a shock-capturing code employing a high-order Godunov scheme to track large density variations induced by shocks. We investigate the robustness of the standard relation between the logarithmic density variance (
$\sigma _s^2$
) and the sonic Mach number (
$\mathcal {M}$
) of isothermal interstellar turbulence, in the non-isothermal regime. Specifically, we test ideal gases with diatomic molecular (γ = 7/5) and monatomic (γ = 5/3) adiabatic indices. A periodic cube of gas is stirred with purely solenoidal forcing at low wavenumbers, leading to a fully developed turbulent medium. We find that as the gas heats in adiabatic compressions, it evolves along the relationship in the density variance–Mach number plane, but deviates significantly from the standard expression for isothermal gases. Our main result is a new density variance–Mach number relation that takes the adiabatic index into account:
$\sigma _s^2=\ln \left(1+b^2 \mathcal {M}^{(5\gamma +1)/3}\right)$
and provides good fits for
$b\mathcal {M}\lesssim 1$
. A theoretical model based on the Rankine–Hugoniot shock jump conditions is derived,
$\sigma _s^2 = \ln \lbrace 1 + (\gamma +1)b^2\mathcal {M}^2/(\gamma -1)b^2\mathcal {M}^2+2\rbrace$
, and provides good fits also for
$b\mathcal {M}>1$
. We conclude that this new relation for adiabatic turbulence may introduce important corrections to the standard relation, if the gas is not isothermal (γ ≠ 1).
Abstract
We present the Stromlo Stellar Tracks, a set of stellar evolutionary tracks, computed by modifying the Modules for Experiments in Stellar Astrophysics (MESA) 1D stellar evolution package, to ...fit the Galactic Concordance abundances for hot (
T
> 8000 K) massive (≥10
M
⊙
) main-sequence (MS) stars. Until now, all stellar evolution tracks have been computed at solar, scaled-solar, or
α
-element-enhanced abundances, and none of these models correctly represent the Galactic Concordance abundances at different metallicities. This paper is the first implementation of Galactic Concordance abundances to the stellar evolution models. The Stromlo tracks cover massive stars (10 ≤
M
/
M
⊙
≤ 300) with varying rotations (
v
/
v
crit
= 0.0, 0.2, 0.4) and a finely sampled grid of metallicities (−2.0 ≤ Z/H ≤ +0.5; ΔZ/H = 0.1) evolved from the pre-main sequence to the end of
12
C burning. We find that the implementation of Galactic Concordance abundances is critical for the evolution of MS, massive hot stars in order to estimate accurate stellar outputs (
L
,
T
eff
,
g
), which, in turn, have a significant impact on determining the ionizing photon luminosity budgets. We additionally support prior findings of the importance that rotation plays on the evolution of massive stars and their ionizing budget. The evolutionary tracks for our Galactic Concordance abundance scaling provide a more empirically motivated approach than simple uniform abundance scaling with metallicity for the analysis of H
ii
regions and have considerable implications for determining nebular emission lines and metallicity. Therefore, it is important to refine existing stellar evolutionary models for comprehensive high-redshift extragalactic studies. The Stromlo tracks are available to the astronomical community.
The rapid development of organic-inorganic hybrid perovskite solar cells has resulted in laboratory-scale devices having power conversion efficiencies that are competitive with commercialised ...technologies. However, hybrid perovskite solar cells are yet to make an impact beyond the research community, with translation to large-area devices fabricated by industry-relevant manufacturing methods remaining a critical challenge. Here we report the first demonstration of hybrid perovskite solar cell modules, comprising serially-interconnected cells, produced entirely using industrial roll-to-roll printing tools under ambient room conditions. As part of this development, costly vacuum-deposited metal electrodes are replaced with printed carbon electrodes. A high-throughput experiment involving the analysis of batches of 1600 cells produced using 20 parameter combinations enabled rapid optimisation over a large parameter space. The optimised roll-to-roll fabricated hybrid perovskite solar cells show power conversion efficiencies of up to 15.5% for individual small-area cells and 11.0% for serially-interconnected cells in large-area modules. Based on the devices produced in this work, a cost of ~0.7 USD W
is predicted for a production rate of 1,000,000 m² per year in Australia, with potential for further significant cost reductions.
ABSTRACT We present a simplified model of active galactic nucleus (AGN) continuum emission designed for photoionization modeling. The new model oxaf reproduces the diversity of spectral shapes that ...arise in physically based models. We identify and explain degeneracies in the effects of AGN parameters on model spectral shapes, with a focus on the complete degeneracy between the black hole mass and AGN luminosity. Our reparametrized model oxaf removes these degeneracies and accepts three parameters that directly describe the output spectral shape: the energy of the peak of the accretion disk emission , the photon power-law index of the non-thermal emission Γ, and the proportion of the total flux that is emitted in the non-thermal component . The parameter is presented as a function of the black hole mass, AGN luminosity, and "coronal radius" of the optxagnf model upon which oxaf is based. We show that the soft X-ray excess does not significantly affect photoionization modeling predictions of strong emission lines in Seyfert narrow-line regions. Despite its simplicity, oxaf accounts for opacity effects where the accretion disk is ionized because it inherits the "color correction" of optxagnf. We use a grid of mappings photoionization models with oxaf ionizing spectra to demonstrate how predicted emission-line ratios on standard optical diagnostic diagrams are sensitive to each of the three oxaf parameters. The oxaf code is publicly available in the Astrophysics Source Code Library.
Summary Background Guidelines differ about the value of assessment of adiposity measures for cardiovascular disease risk prediction when information is available for other risk factors. We studied ...the separate and combined associations of body-mass index (BMI), waist circumference, and waist-to-hip ratio with risk of first-onset cardiovascular disease. Methods We used individual records from 58 cohorts to calculate hazard ratios (HRs) per 1 SD higher baseline values (4·56 kg/m2 higher BMI, 12·6 cm higher waist circumference, and 0·083 higher waist-to-hip ratio) and measures of risk discrimination and reclassification. Serial adiposity assessments were used to calculate regression dilution ratios. Results Individual records were available for 221 934 people in 17 countries (14 297 incident cardiovascular disease outcomes; 1·87 million person-years at risk). Serial adiposity assessments were made in up to 63 821 people (mean interval 5·7 years SD 3·9). In people with BMI of 20 kg/m2 or higher, HRs for cardiovascular disease were 1·23 (95% CI 1·17–1·29) with BMI, 1·27 (1·20–1·33) with waist circumference, and 1·25 (1·19–1·31) with waist-to-hip ratio, after adjustment for age, sex, and smoking status. After further adjustment for baseline systolic blood pressure, history of diabetes, and total and HDL cholesterol, corresponding HRs were 1·07 (1·03–1·11) with BMI, 1·10 (1·05–1·14) with waist circumference, and 1·12 (1·08–1·15) with waist-to-hip ratio. Addition of information on BMI, waist circumference, or waist-to-hip ratio to a cardiovascular disease risk prediction model containing conventional risk factors did not importantly improve risk discrimination (C-index changes of −0·0001, −0·0001, and 0·0008, respectively), nor classification of participants to categories of predicted 10-year risk (net reclassification improvement −0·19%, −0·05%, and −0·05%, respectively). Findings were similar when adiposity measures were considered in combination. Reproducibility was greater for BMI (regression dilution ratio 0·95, 95% CI 0·93–0·97) than for waist circumference (0·86, 0·83–0·89) or waist-to-hip ratio (0·63, 0·57–0·70). Interpretation BMI, waist circumference, and waist-to-hip ratio, whether assessed singly or in combination, do not importantly improve cardiovascular disease risk prediction in people in developed countries when additional information is available for systolic blood pressure, history of diabetes, and lipids. Funding British Heart Foundation and UK Medical Research Council.
FMR1
premutation carriers are common in the general population (1/130–260 females and 1/250–810 males) and can be affected by fragile X‐associated tremor ataxia syndrome, fragile X‐associated primary ...ovarian insufficiency, anxiety, depression, hypertension, sleep apnea, fibromyalgia, and hypothyroidism. Here we report the results of a pilot study to assess the prevalence and risk of migraine in FMR1 premutation carriers. Three hundred fifteen carriers (203 females; 112 males) and 154 controls (83 females; 71 males) were seen sequentially as part of a family study. A standardized medical history, physical examination and confirmation of diagnosis of migraine headaches were performed by a physician. The prevalence of migraine was 54.2% in female carriers (mean age/SD: 49.60/13.73) and 26.79% in male carriers (mean age/SD: 59.94/14.27). This prevalence was higher compared to female (25.3%; mean age/SD: 47.60/15.21; p = 0.0001) and male controls (15.5%; mean age/SD; 53.88/13.31; p = 0.0406) who underwent the same protocol and were confirmed to be negative for the FMR1 mutation by DNA testing. We hypothesize that the increased prevalence of migraine headaches in FMR1 premutation carriers is likely related to the mitochondrial abnormalities that have recently been reported. Screening for migraine should be considered when evaluating FMR1 premutation carriers in the future.
Abstract Introduction Although plasminogen activator inhibitor (PAI-1) plays a key regulatory role in fibrinolysis, it has not been clearly shown to independently predict cardiovascular disease (CVD) ...among individuals without prior CVD. We investigated, in the Framingham Heart Study offspring cohort, whether PAI-1 predicted CVD risk among individuals without prior CVD. Methods Plasma PAI-1 antigen and tissue plasminogen activator (TPA) antigen were measured in 3203 subjects without prior CVD between 1991 and 1995; average follow-up of 10 years. PAI-1 was remeasured 4 years after baseline, to determine the effect of serial change on risk. Results PAI-1 levels (mean ± SD) were 29.1 ng/ml (19.2) versus 22.1 (16.5) for those and without incident CVD; p < 0.001, and TPA levels were 12.0 ng/ml (5.7) versus 9.0 (4.7); p < 0.001. PAI-1 and TPA antigen levels had a strong unadjusted linear relation with incident CVD (p < 0.001). After adjustment for conventional risk factors, the hazard ratios (HRs) for higher quartiles of PAI-1, compared with the lowest, were 1.9, 1.9, 2.6 (linear trend p = 0.006), and 1.6, 1.6, 2.9 (p < 0.001) for TPA antigen. The adjusted HRs for increasing quartiles of serial change in PAI-1 at 4 years, compared with the lowest, were 0.9, 0.8, 1.3 (p = 0.050). C statistic assessment showed that adding PAI-1 or TPA to conventional risk factors resulted in small increases in discrimination and modest reclassification of risk, which was statistically significant for TPA (net reclassification 6.8%, p = 0.037) but not PAI-1 (4.8%, p = 0.113). Conclusion PAI-1 and TPA antigen levels are predictive of CVD events after accounting for established risk factors. A serial increase in PAI-1 is associated with a further increase in risk. These findings support the importance of fibrinolytic potential in CVD.
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