Miracle-dz/UniFAR-FTUs huggingface dataset:
The Spectral and Environment Properties of z ∼ 2.0–2.5 Quasar Pairs

We present the first results from our survey of intervening and proximate Lyman limit systems (LLSs) at z ∼ 2.0–2.5 using the Wide Field Camera 3 on board the Hubble Space Telescope. The quasars in our sample are projected pairs with proper transverse separations R⊥ ≤ 150 kpc and line-of-sight velocity separations ≲11,000 km s−1. We construct a stacked ultraviolet (rest-frame wavelengths 700–2000 Å) spectrum of pairs corrected for the intervening Lyman forest and Lyman continuum absorption. The observed spectral composite presents a moderate flux excess for the most prominent broad emission lines, a ∼30% decrease in flux at λ = 800–900 Å compared to a stack of brighter quasars not in pairs at similar redshifts, and lower values of the mean free path of the H i ionizing radiation for pairs ( = 140.7 ± 20.2 Mpc) compared to single quasars ( = 213.8 ± 28 Mpc) at the average redshift z ≃ 2.44. From the modeling of LLS absorption in these pairs, we find a higher (∼20%) incidence of proximate LLSs with log ≥ 17.2 at δv < 5000 km s−1 compared to single quasars (∼6%). These two rates are different at the 5σ level. Moreover, we find that optically thick absorbers are equally shared between foreground and background quasars. Based on these pieces of evidence, we conclude that there is a moderate excess of gas-absorbing Lyman continuum photons in our closely projected quasar pairs compared to single quasars. We argue that this gas arises mostly within large-scale structures or partially neutral regions inside the dark matter halos where these close pairs reside.
Superconducting Metamaterials

Evanescent wave amplification has been predicted under the ideal condition that the index of refraction, n = -1 + i 0 precisely, but is difficult to observe in practice because current metamaterials suffer from high losses. We present experimental results on a metamaterial that employs superconducting Nb metals and low-loss dielectric materials. Results include transmission data on a wire, split-ring resonator, and a combination medium at temperatures between 4.2 K and 297 K. Evidence of negative effective permittivity, permeability, and a negative effective index passband are seen in the superconducting state between 50 MHz and 18 GHz. We find a dielectric loss of ε eff , 2 = 2.6 x 10 -3 in a superconducting wire array at 10.75 GHz.
The non-uniformity of galaxy cluster metallicity profiles

We study a sample of 207 nearby galaxy groups and clusters observed with XMM-Newton. Key aspects of this sample include the large size, the high data quality, and the large diversity of cluster dynamical states. We determine the overall metallicity within 0.3R$_{500}$ and the radial distribution of the metals. On average, we find a mild dependence of the core metallicity with the average temperature of the system in agreement with previous results. However, we identify the cause of this mild dependence to be due to relaxed systems only; disturbed systems do not show this trend, on average. The large scatter observed in this relation is strongly associated with the dynamical state of the systems: relaxed systems have on average a higher metallicity in the core than disturbed objects. The radial profiles of relaxed systems are centrally peaked and show a steep decrease with radius, flattening beyond 0.3-0.4R$_{500}$. The metallicity of disturbed systems is also higher in the center but at much lower values than what is observed for relaxed objects. This finding is consistent with the picture that cluster mergers mix the abundance distribution by inducing large scale motions. The scatter of the radial profiles is quite large, but while for relaxed systems it decreases almost monotonically as function of the radius, for disturbed systems it shows a significant boost at large radii. Systems with a central radio source have a flatter profile indicating that central AGNs are an efficient mechanism to uplift and redistribute the metals in the ICM.
Faint-Source Counts from Off-Source Fluctuation Analysis on Chandra Observations of the Hubble Deep Field-North

We report the results of fluctuation analysis of the off-source field from the 1 million second Chandra observation of the Hubble Deep Field-North (HDF-N). The distribution of the counts in cells has been compared with the expectations from the log N-log S model to constrain the behavior of the source number density down to a factor of several lower than the source detection limit. Our results show that the number counts in the soft band (0.5-2 keV) continue to grow down to SX ~ 7 × 10-18 ergs s-1 cm-2, possibly suggesting the emergence of a new population, and agree well with a prediction of star-forming galaxies by Ptak et al. The fluctuation analysis can loosely constrain the source counts fainter than the detection limit, and we found an upper limit of ≲10,000 sources deg-2 at SX ~ 2 × 10-16 ergs s-1 cm-2 in the hard (2-10 keV) band.
Making Space for Midwifery in a Hospital: Exploring the Built Birth Environment of Canada’s First Alongside Midwifery Unit

Background: Canada’s first alongside midwifery unit (AMU) was intentionally informed by evidence-based birth environment design principals, building on the growing evidence that the built environment can shape experiences, satisfaction, and birth outcomes. Objectives: To assess the impact of the built environment of the AMU for both service users and midwives. This study aimed to explore the meanings that individuals attribute to the built environment and how the built environment impacted people’s experiences. Methods: We conducted a mixed-methods study using a grounded theory methodology for data collection and analysis. Our research question and data collection tools were underpinned by a sociospatial conceptual approach. All midwives and all those who received midwifery care at the unit were eligible to participate. Data were collected through a structured online survey, interviews, and focus group. Results: Fifty-nine participants completed the survey, and interviews or focus group were completed with 28 service users and 14 midwives. Our findings demonstrate high levels of satisfaction with the birth environment. We developed a theoretical model, where “making space” for midwifery in the hospital contributed to positive birth experiences and overall satisfaction with the built environment. The core elements of this model include creating domestic space in an institutional setting, shifting the technological approach, and shared ownership of the unit. Conclusions: Our model for creating, shifting, and sharing as a way to make space for midwifery can serve as a template for how intentional design can be used to promote favorable outcomes and user satisfaction.
Anisotropies of ultra-high energy cosmic rays dominated by a single source in the presence of deflections

This work presents a scenario of ultra-high energy cosmic ray source distribution where a nearby source is solely responsible for the anisotropies in arrival directions of cosmic rays while the rest of the sources contribute only isotropically. An analytical approach focused on large-scale anisotropies, which are influenced by deflections in a Kolmogorov-type turbulent magnetic field, is employed to provide more general results. When the recent Pierre Auger Observatory angular power spectrum above 8 EeV is used the restricted model gives, under the assumption of the small angle approximation, a solution where the RMS deflection with respect to the line of sight is αrms = (50-10+11)̂, while the relative flux from the single source η=0.03 ± 0.01. Furthermore, the solution can be translated into constraints on the source distance, luminosity, and extra-galactic magnetic field strength. For Centaurus A and the Virgo cluster the required relation between the coherence length and the RMS magnetic field strength is obtained: a coherence length of ∼ 100 kpc would imply the RMS field strength around 1 nG for iron dominated and above 10 nG for proton dominated composition. We also performed trajectory simulations with our publicly available code CRPropa to show that our analytical model can serve as a good approximation as long as the deflections in cosmic magnetic fields can be described as a random walk. The simulations showed that generally structured fields tend to suppress large-scale anisotropies, especially the dipole, compared to anisotropies at smaller scales described by higher multipoles.
CHANDRA OBSERVATIONS OF THE X-RAY POINT SOURCE POPULATION IN NGC 4636

We present the X-ray point-source population in the nearby Virgo elliptical galaxy NGC 4636 from three Chandra X-ray observations. These observations, totaling ∼193 ks after time filtering, were taken with the Advanced CCD Imaging Camera (ACIS) over a three-year period. Using a wavelet decomposition detection algorithm, we detect 318 individual point sources. For our analysis, we use a subset of 277 detections with ⩾ net 10 counts (a limiting luminosity of approximately 1.2 × 1037 erg s−1 in the 0.5–2 keV band, outside the central 1.′5 bright galaxy core). We present a radial distribution of the point sources. Between 1. ′5 and 6′ from the center, 25% of our sources are likely to be background sources (active galactic nuclei (AGNs)) and 75% are low-mass X-ray binaries (LMXBs) within the galaxy, while at radial distances greater than 6′, background sources (AGN) will dominate the point sources. We explore short and long-term variability (over timescales of 1 day to three years) for X-ray point sources in this elliptical galaxy. 54 sources (24%) in the common ACIS fields of view show significant variability between observations. Of these, 37 are detected with at least 10 net counts in only one observation and thus may be “transient. ” In addition, ∼10% of the sources in each observation show significant short-term variability; we present an example light curve for a variable bright source. The cumulative luminosity function (LF) for the point sources in NGC 4636 can be represented as a power law of slope α = 1.14 ± 0.03. We do not detect, but estimate an upper limit of ∼4.5 × 1037 erg s−1 to the current X-ray luminosity of the historical supernova SN1939A. We find 77 matches between X-ray point sources and globular cluster (GC) candidates found in deep optical images of NGC 4636. In the annulus from 1. ′5 to 6′ of the galaxy center, 48 of the 129 X-ray point sources (37%) with ⩾10 net counts are matched with GC candidates. Since we expect 25% of these sources to be background AGN, the percentage matched with GCs could be as high as 50%. Of these matched sources, we find that ∼70% are associated with the redder GC candidates, those that are thought to have near-solar metal abundance. The fraction of GC candidates with an X-ray point source match decreases with decreasing GC luminosity. We do not find a correlation between the X-ray luminosities of the matched point sources and the luminosity or color of the host GC candidates. The LFs of the X-ray point sources matched with GCs and those that are unmatched have similar slopes over 1.8 × 1037 erg s−1 ⩽ Lx ⩽ 1 × 1038 erg s−1. Finally, we present a color–color diagram based on ratios of X-ray flux rather than source counts, which yields a much tighter source distribution, and shows a large population of sources which are likely LMXBs and a small population of black hole candidates.
Two-dimensional electron gases induced by polarization charges in AlN/GaN heterostructure grown by plasma-assisted molecular-beam epitaxy

We discuss the growth and transport properties of two-dimensional electron gas confined at the AlN/GaN heterointerface grown by plasma-assisted molecular-beam epitaxy. The sheet carrier density was found to be highly dependent on the barrier thickness of AlN grown on a doped or undoped GaN layer. The carrier sheet density monotonously increased from 0.8×1012 to 1.1×1013 cm−2 as the AlN barrier thickness on a semi-insulating GaN layer increased from 15 to 25 A due to spontaneous and piezoelectric polarization. An AlN barrier of 35 A in thickness grown on n-GaN gave the highest sheet carrier density, which was 4.3×1013 cm−2. In thin AlN barrier layers, the sheet carrier density was low due to surface depletion.
1/4 BPS circular loops, unstable world-sheet instantons and the matrix model

The standard prescription for computing Wilson loops in the AdS/CFT correspondence in the large coupling regime and tree-level involves minimizing the string action. In many cases the action has more than one saddle point as in the simple example studied in this paper, where there are two 1/4 BPS string solutions, one a minimum and the other not. Like in the case of the regular circular loop the perturbative expansion seems to be captured by a free matrix model. This gives enough analytic control to extrapolate from weak to strong coupling and find both saddle points in the asymptotic expansion of the matrix model. The calculation also suggests a new BMN-like limit for nearly BPS Wilson loop operators.
Normal modes in magnetized two-fluid spin quantum plasmas

We extend the classical two-fluid magnetohydrodynamic (MHD) formalism to include quantum effects such as electron Fermi pressure, Bohm pressure and spin couplings. At scales smaller than the electron skin-depth, the Hall effect and electron inertia must be taken into account, and can overlap with the quantum effects. We write down the full set of two-fluid quantum MHD (QMHD) and analyze the relative importance ofthese effects in the high density environments of neutron star atmospheres and white dwarf interiors, finding that for a broad range of parameters all these effects are operative. Of all spin interactions we analyze only the spin-magnetic coupling, as it is linear in $\hbar$ and consequently it is the strongest spin effect. We re-obtain the classical two-fluid MHD dispersion relations corresponding to the magnetosonic and Alfven modes, modified by quantum effects. In the zero-spin case, for propagation parallel to the magnetic field, we find that the frequency of the fast mode is due to quantum effects modified by electron inertia, while the frequency of the Alfven-slow sector has no quantum corrections. For perpendicular propagation, the fast-mode frequency is the same as for the parallel propagation plus a correction due only to classical two-fluid effects. When spin is considered, a whistler mode appears, which is due to two-fluid spin-magnetic interaction. There are no modifications due to spin for parallel propagation of magnetosonic and Alfven waves, while for perpendicular prop agation a dispersive term due to spin arises in the two-fluid expression for the fast magnetosonic mode.
Does the Danube exist? Versions of reality given by various regional climate models and climatological data sets

[1] We present an auditing (intercomparison and verification) of several regional climate models (RCMs) nested into the same run of the same atmospheric global circulation model (AGCM) regarding their representation of the statistical properties of the hydrological balance of the Danube river basin for 1961–1990. We also consider the data sets produced by the driving AGCM, by the European Centre for Medium-Range Weather Forecasts (ECMWF) and National Centers for Environmental Prediction (NCEP)–National Center for Atmospheric Research (NCAR) reanalyses. The hydrological balance is computed by integrating the precipitation and evaporation fields over the area of interest. Large discrepancies exist among RCMs for the monthly climatology as well as for the mean and variability of the annual balances, and only few data sets are consistent with the observed discharge values of the Danube at its Delta, even if the driving AGCM provides itself an excellent estimate. We find consistently that, for a given model, increases in the resolution do not alter the net water balance, while speeding up the hydrological cycle through the enhancement of both precipitation and evaporation by the same amount. Since the considered approach relies on the mass conservation principle and bypasses the details of the air-land interface modeling, we propose that the atmospheric components of RCMs still face difficulties in representing the water balance even on a relatively large scale. Their reliability on smaller river basins may be even more problematic. Moreover, since for some models the hydrological balance estimates obtained with the runoff fields do not agree with those obtained via precipitation and evaporation, some deficiencies of the land models are also apparent. The driving AGCM greatly overperforms the NCEP-NCAR and ECMWF 40-year (ERA-40) reanalyses, which result to be largely inadequate for representing the hydrology of the Danube river basin, both for the reconstruction of the long-term averages and of the seasonal cycle. The reanalyses cannot in any sense be used as verification. We suggest that these results should be carefully considered in the perspective of auditing climate models and assessing their ability to simulate future climate changes.
Antihypertensive medication classes and the risk of dementia over a decade of follow-up

Introduction: Use of angiotensin II (ATII)-stimulating antihypertensive medication (AHM), including angiotensin receptor blockers (ARBs) and dihydropyridine calcium channel blockers (CCBs), has been associated with lower dementia risk. Previous studies had relatively short follow-up periods. The aim of this study is to investigate if these effects are sustained over longer periods. Methods: This post hoc observational analysis was based on data from a dementia prevention trial (preDIVA and its observational extension), among Dutch community-dwelling older adults without prior diagnosis of dementia. Differential associations between AHM classes and incident dementia were studied after 7.0 and 10.4 years, based on the median follow-up durations of dementia cases and all participants. Results: After 7 years, use of ATII-stimulating antihypertensives [hazard ratio = 0.68, 95% confidence interval (CI) = 0.47–1.00], ARBs (hazard ratio = 0.54, 95% CI = 0.31–0.94) and dihydropyridine CCBs (hazard ratio = 0.52, 95% CI = 0.30–0.91) was associated with lower dementia risk. After 10.4 years, associations for ATII-stimulating antihypertensives, ARBs and dihydropyridine CCBs attenuated (hazard ratio = 0.80, 95% CI = 0.61–1.04; hazard ratio = 0.75, 95% CI = 0.53–1.07; hazard ratio = 0.73, 95% CI = 0.51–1.04 respectively), but still suggested lower dementia risk when compared with use of other AHM classes. Results could not be explained by competing risk of mortality. Conclusion: Our results suggest that use of ARBs, dihydropyridine CCBs and ATII-stimulating antihypertensives is associated with lower dementia risk over a decade, although associations attenuate over time. Apart from methodological aspects, differential effects of antihypertensive medication classes on incident dementia may in part be temporary, or decrease with ageing.
Upregulation of Neurotrophic Factors and Myelin Basic Protein in Schwann-like Cells by T3 Hormone Following Transdifferentiation of Human Adipose-derived Stem Cells

Peripheral nerve regeneration is a complicated phenomenon. Thyroid hormones are known as critical regulators in the nervous system development. The Schwann cells have the regenerative potency in the peripheral nervous system. In this study, the human adipose-derived stem cells were assessed in vitro, for transdifferentiation potency into Shwann-like cells (SLCs) as a candidate source for clinical cell therapy, under the treatment of triiodothyronine (T3) hormone, and compared with the untreated cells. The cell viability rate, myelination and neurotrophic factors expression of SLCs were evaluated two weeks post- induction by MTT assay, immunocytochemistry and real-time RT-PCR techniques, respectively. The obtained results revealed a significant decrease in SLCs viability, compared to the adipose-derived stem cells (P < 0.001). Immunocytochemistry technique was applied to detect SLCs markers, such as S100β, GFAP and myelin basic proteins (MBP) in the presence and absence of T3 treatment. The results indicated that administering T3 can significantly increase the differentiation and myelination potency of SLCs (P < 0.01). The findings of real-time RT-PCR technique indicated that the expression of Schwann cells markers, MBP, brain-derived neurotrophic factor and glial cell-derived neurotrophic factor were upregulated significantly with T3 hormone administration in comparison with the untreated cells (P < 0.05). The SLCs were able to express the neurotrophic factors and myelination related genes in the presence of T3 hormone. Furthermore, T3 administration improved myelination potency of adipose-derived stem cells, in vitro. Further in vivo experiments are necessary to confirm the advantages of using a combination of autologous SLCs and T3 hormone for peripheral nerve injury recovery.
Glueball spectrum from a potential model

The spectrum of two-gluon glueballs below 3 GeV is investigated in a potential model with a dynamical gluon mass using the variational method. The short-distance potential is approximated by one-gluon exchange, while the long-distance part is taken as a breakable string. The mass and size of the radial as well as orbital excitations up to a principle quantum number $n=3$ are evaluated. The predicted mass ratios are compared with experimental candidates and lattice results.
Statistical Theory for the Diffusion of a Passive Scalar in Turbulent Shear Flows

The diffusion of a passive scalar in turbulent shear flows is studied from the statistical viewpoint. The scalar flux, the scalar variance, and the squared-scalar flux, which characterize the diffusion processes, are calculated from the two-scale Direct-Interaction formalism. An equation for the time evolution of the scalar variance at high Reynolds and Peclet numbers is shown to be written by using the mean scalar and two statistical quantities, such as the turbulent energy and the energy dissipation rate of the velocity field.
Cognitive Performance following Single- or Multi-Session Exercise Intervention in Middle Age: A Systematic Review

ABSTRACT Background Research in modifiable behaviors, like exercise, on risk for dementia is increasing. Although many studies focus on older adults, brain pathology for Alzheimer’s Disease can begin in middle age, suggesting an ideal target for intervention. Methods We conducted a systematic review from exercise intervention studies on cognitive function among healthy, middle-aged participants (45-65). We searched multiple databases (PubMed, PsycINFO, MEDLINE, Cochrane Central Register of Controlled Trials, Google Scholar) for studies using standard, validated, neuropsychological measures following either single- or multi-session interventions in cognitively-unimpaired, middle-aged adults. Results We identified 13 eligible studies. There was notable heterogeneity across studies, with varying design, measures, interventions, and results. Results from single-session studies showed improvement in response inhibition, while results for cognitive flexibility were mixed. No significant changes were found on measures of attention, working memory, or processing speed. Results from multi-session studies were more varied. Verbal memory was found to improve while performance on tests of attention and working memory, processing speed, and executive function were mixed. Conclusion Importantly, for both single-session and multi-session studies, there was no standard set of neuropsychological tests administered, making it more difficult to synthesize the findings into a single narrative. We end with a discussion on future directions and implementation.