The Space Density of Ultra-luminous QSOs at the End of Reionization Epoch by the QUBRICS Survey and the AGN Contribution to the Hydrogen Ionizing Background

Motivated by evidences favoring a rapid and late hydrogen reionization process completing at z ∼ 5.2–5.5 and mainly driven by rare and luminous sources, we have reassessed the estimate of the space density of ultra-luminous QSOs at z ∼ 5 in the framework of the QUBRICS survey. A ∼ 90% complete sample of 14 spectroscopically confirmed QSOs at M 1450 ≤ −28.3 and 4.5 ≤ z ≤ 5.0 has been derived in an area of 12,400 deg2, thanks to multiwavelength selection and Gaia astrometry. The space density of z ∼ 5 QSOs within −29.3 ≤ M 1450 ≤ −28.3 is three times higher than previous determinations. Our results suggest a steep bright-end slope for the QSO luminosity function at z ∼ 5 and a mild redshift evolution of the space density of ultrabright QSOs (M 1450 ∼ −28.5) at 3 < z < 5.5, in agreement with the redshift evolution of the much fainter active galactic nucleus (AGN) population at M 1450 ∼ −23. These findings are consistent with a pure density evolution for the AGN population at z > 3. Adopting our z ∼ 4 QSO luminosity function and applying a mild density evolution in redshift, a photoionization rate of Γ HI = 0.46 − 0.09 + 0.17 × 10 − 12 s − 1 has been obtained at z = 4.75, assuming an escape fraction of ∼70% and a steep faint-end slope of the AGN luminosity function. The derived photoionization rate is ∼50–100% of the ionizing background measured at the end of the reionization epoch, suggesting that AGNs could play an important role in the cosmological reionization process.

Kinematics of the Milky Way Thick disk in solar neighborhood

Using GAIA EDR3 catalog, we present the detailed analysis of the two-component Milky Way stellar disk in the solar neighborhood. To determine the kinematical properties of the thin and of the Thick disks, we select the complete sample of about 278,000 evolved red giant branch (RGB) stars distributed in the cylinder of 1 kpc radius and 0.5 kpc height centered at the Sun. We measured the following mean velocities and dispersions for the thin and the Thick disks, respectively: [Formula: see text][Formula: see text]km s[Formula: see text] with [Formula: see text][Formula: see text]km s[Formula: see text], and [Formula: see text][Formula: see text]km s[Formula: see text] with [Formula: see text][Formula: see text]km s[Formula: see text]. Errors in mean velocities and dispersions are all less than 1[Formula: see text]km s[Formula: see text]. Same values were computed on much smaller subsamples of our Gaia data with RAVE DR5 [Fe/H] values, from which a metallicity selection was added. Results are basically the same. We find that up to 500 pc height above/below the galactic plane, Thick disk stars comprise about half the stars of the disk. We also find evidence of a substructure in [Formula: see text] versus [Formula: see text] in the thick disk population mostly that would give support to the accretion scenario for the formation of the thick disk.

Ubiquitous [O ii] Emission in Quiescent Galaxies at z ≈ 0.85 from the LEGA-C Survey*

Using deep rest-frame optical spectroscopy from the Large Early Galaxy Astrophysical Census (LEGA-C) survey, conducted using VIMOS on the ESO Very Large Telescope, we search for low-ionization [O ii] λ λ 3726,3729 emission in the spectra of a mass-complete sample of z ≈ 0.85 galaxies. We find that 59% of UVJ-quiescent (i.e., non-star-forming) galaxies in the sample have [O ii] emission detected above our completeness limit of 1.5 Å, and the median-stacked spectrum of the remaining sample also shows [O ii] emission. The overall fraction of sources with [O ii] above our equivalent width limit is comparable to what we find in the low-redshift universe from GAMA and MASSIVE, except perhaps at the highest stellar masses (>1011.5 M ⊙). However, stacked spectra for the individual low-equivalent-width systems uniquely indicates ubiquitous [O ii] emission in the higher-z LEGA-C sample, with typical [O ii] luminosities per unit stellar mass that are a factor of ×3 larger than the lower-z GAMA sample. Star formation at higher-z could play a role in producing the [O ii] emission, although it is unlikely to provide the bulk of the ionizing photons. More work is required to fully quantify the contributions of evolved stellar populations or active galactic nuclei to the observed spectra.

A Survey of Novae in M83

The results of the first synoptic survey of novae in the barred spiral and starburst galaxy, M83 (NGC 5236), are presented. A total of 19 novae and one background supernova were discovered during the course of a nearly 7 year survey comprised of over 200 individual nights of observation between 2012 December 12 and 2019 March 14. After correcting for the limiting magnitude and the spatial and temporal coverage of the survey, the nova rate in M83 was found to be R = 19+5 −3 yr−1. This rate, when normalized to the K-band luminosity of the galaxy, yields a luminosity-specific nova rate, ν K = 3.0+0.9 −0.6 × 10−10 yr −1 L ⊙,K −1. The spatial distribution of the novae is found to be more extended than the overall galaxy light suggesting that the observed novae are likely dominated by a disk population. This result is consistent with the observed novae light curves, which reveals that the M83 novae are on average more luminous at maximum light and fade faster when compared with novae observed in M31. Generally, the more luminous M83 novae were observed to fade more rapidly, with the complete sample being broadly consistent with a linear maximum magnitude versus rate of decline relation.

PCR and Culture Analysis of Streptococcus pneumoniae Nasopharyngeal Carriage in Healthy Children

Invasive Streptococcus pneumoniae disease is preceded by asymptomatic nasopharyngeal carriage. Measuring carriage in healthy populations provides data on what serotypes are present in communities, which is of interest in the era of polyvalent pneumococcal conjugate vaccines. Nasopharyngeal swabs from a survey of 682 and 800 healthy children in 2016 and 2018, respectively, were analyzed by culture and Quellung reaction to determine rates of carriage and serotypes. All swabs from 2016 and 300 randomly selected swabs from 2018 were then analyzed using real-time semi-quantitative PCR (qPCR) to detect S. pneumoniae gene targets lytA, piaA, and SP2020 and determine serotype. There were 71 (10.4%) and 68 (8.5%) culture positive samples in 2016 and 2018, respectively. All of these were also positive by qPCR except one that was equivocal. In total, 46.0% of 2016 swabs were positive by qPCR. In 2018, results from the selected sample extrapolated to the complete sample showed 49.0% positive by qPCR. PCV13 serotypes were detected in 29.3% and 21.7% of S. pneumoniae qPCR positive samples from 2016 and 2018, respectively; compared with only 8.4% and 6.0% PCV13 serotypes detected by Quellung reaction in culture positive samples. Compared with culture, qPCR detected S. pneumoniae more frequently. Further, qPCR serotyping detected PCV13 serotypes in a larger proportion of samples than culture and Quellung reaction did, showing that, despite established universal childhood PCV13 immunization, vaccine serotypes can still be detected in a large proportion of young children.

Regional brands produced beyond the region: An analysis of beer brands from recently closed breweries in Europe

Global industry has been undergoing changes in the concentration of brand ownership and production, with acquisitions and closures being a major factor in this evolution. The impacts of such activities are commonly studied from an economic perspective and from the perspective of internal firm-level and deal-level factors, while the influence of external geographical factors is largely neglected. Our research focuses mainly on the importance of geographical cultural factors affecting beer brands whose production location was moved after the closure of the original breweries. The research includes a complete sample of 30 brands from recently closed breweries across Europe. Brands are divided into seven categories according to how their marketing strategy has (or has not) changed in terms of exploiting regional and national identity. The overall success of these brands is then measured in terms of the development of their share in the home countries’ markets. Differences in brands’ strategies and successes are explained through a wide range of country-level factors and the individual characteristics of the breweries. It is shown that the level of beer tradition or identity in the countries, as well as the country’s beer life-cycle position, plays a crucial role in the evolution of the studied brands.

National Non-verbal Cognitive Ability Test (BNV) Development Study

The aim of the present study is to develop a national non-verbal cognitive ability test in Turkey. Test items were developed during the first stage and applied as a pilot study on 3,073 children in the age interval of 4 to 13. The test was given its final form based on the values of item difficulty, item distinctiveness, item total score correlation. Norm study was carried out at 12 different provinces with a total of 9,129 children comprised of 4,464 females (49%) and 4,665 (51%) males. Test-retest, split-halves, KR-20, and KR-21 methods were applied for the reliability analyses of the study. Standard error, standard deviation, and reliability coefficient were calculated for the measurement. Content and construct validity along with criterion-related validity analysis methods were used for validity analyses. The KR-20 reliability coefficient obtained from the complete sample group was estimated as 0.92. Test-retest reliability coefficient was determined as 0.80. A correlation of .71 was determined between Naglieri Cognitive Ability test and BNV test. A correlation of .67 was determined between Toni-3 test and BNV test while a correlation of .86 was determined between BNV and Colored Progressive Matrices Test.

On the efficiency of type I censored samples

The paper revisits the entropy-based efficiency of the type-I censored sample, which was addressed by several previous works. The main purpose of this work is to provide a comprehensive definition of the efficiency function and give a general proof that the entropy of a censored sample is always less than that of the complete sample for any probability distribution and at any point of censoring. A simulation study is performed to validate our results, and a real-data example is reevaluated.

Bayes Estimation of the Modified Inverse Rayleigh Parameters Under Various Approximation Techniques

In this paper we proposed Bayes estimators for complete sample of the Modified InverseRayleigh (MIR) parameters which was introduced by Khan (2014). Different approximationmethods with squared error loss function (SELF) have been used to develop the bayesestimators for the unknown parameters. The proposed estimators are compared with the correspondingmaximum likelihood estimators by simulation study on the basis of mean squareerror (MSE). To illustrate the usefulness and goodness of fit of Modified Inverse Rayleighdistribution we considered two real data sets.