Miracle-dz/UniFAR-FTUs huggingface dataset:
Using an intervention programme to empower intellectually disabled learners to use WhatsApp in a special needs unit in Cape Town, South Africa

Abstract Although WhatsApp has become so ubiquitous and widespread across the globe, it poses a risk of abuse and cyberbullying to vulnerable groups of people like intellectually disabled learners. This study explores intellectually disabled learners’ experiences of using WhatsApp during an intervention programme in a special needs unit at a school in Cape Town. The study was conducted using a qualitative case study within an interpretive paradigm. Nineteen participants who include intellectually disabled learners, parents/guardians and staff members were purposively selected to participate in the study. Data was collected using observations and interviews. It was found that all learners who participated in the programme were empowered to use the social media effectively and to become responsible digital citizens. The study concluded that a structured intervention programme provides a milestone of achievement in terms of preparing intellectually disabled learners to become digitally competent and to be able to use social media independently.
AN INDEPENDENT ANALYSIS OF KEPLER-4b THROUGH KEPLER-8b

We present two independent, homogeneous, global analyses of the transit light curves, radial velocities, and spectroscopy of Kepler-4b, Kepler-5b, Kepler-6b, Kepler-7b, and Kepler-8b with numerous differences compared to the previous methods. These include: (1) improved decorrelated parameter fitting set used, (2) new limb-darkening coefficients, (3) time stamps modified to barycentric Julian date for consistency with radial velocity data, (4) two different methods for compensating for the long integration time of Kepler long-cadence data, (5) best-fit secondary eclipse depths and excluded upper limits, and (6) fitted mid-transit times, durations, depths, and baseline fluxes for individual transits. We make several determinations not found in the discovery papers. (1) We detect a secondary eclipse for Kepler-7b of depth (47 ± 14) ppm and statistical significance 3. 5σ. We conclude that reflected light is a much more plausible origin than thermal emission and determine a geometric albedo of Ag = (0.38 ± 0.12). (2) We find that an eccentric orbit model for the Neptune-mass planet Kepler-4b is detected at the 2σ level with e = (0.25 ± 0.12). If confirmed, this would place Kepler-4b in a similar category as GJ 436b and HAT-P-11b, as an eccentric, Neptune-mass planet. (3) We find weak evidence for a secondary eclipse in Kepler-5b of 2σ significance and depth (26 ± 17) ppm. The most plausible explanation is reflected light caused by a planet of geometric albedo Ag = (0.15 ± 0.10). (4) A 2. 6σ peak in Kepler-6b TTV periodogram is detected and is not easily explained as an aliased frequency. We find that mean-motion resonant (MMR) perturbers, non-resonant perturbers, and a companion extrasolar moon all provide inadequate explanations for this signal and the most likely source is stellar rotation. (5) We find different impact parameters relative to the discovery papers in most cases, but generally self-consistent when compared to the two methods employed here. (6) We constrain the presence of MMR planets for all five planets through an analysis of the mid-transit times. (7) We constrain the presence of extrasolar moons for all five planets. (8) We constrain the presence of Trojans for all five planets.
Theory of a continuous Mott transition in two dimensions

T specific heat and a non-zero T = 0 resistivity. We predict an interesting universal resistivity jump in the residual resistivity at the critical point as the transition is approached from the metallic side. The crossovers out of the critical region are also studied. Remarkably the initial crossover out of criticality on the metallic side is to a Marginal Fermi Liquid metal. At much lower temperatures there is a further crossover into the Landau Fermi liquid. The ratio of the two crossover scales vanishes on approaching the critical point. Similar phenomena are found in the insulating side. The filling controlled Mott transition is also studied. Implications for experiments on the layered triangular lattice organic material � (ET)2Cu2(CN)3 are discussed. PACS numbers:
TRANSITION REGION AND CHROMOSPHERIC SIGNATURES OF IMPULSIVE HEATING EVENTS. I. OBSERVATIONS

We exploit the high spatial resolution and high cadence of the Interface Region Imaging Spectrograph (IRIS) to investigate the response of the transition region and chromosphere to energy deposition during a small flare. Simultaneous observations from the Reuven Ramaty High Energy Solar Spectroscopic Imager provide constraints on the energetic electrons precipitating into the flare footpoints, while observations of the X-Ray Telescope, Atmospheric Imaging Assembly, and Extreme Ultraviolet Imaging Spectrometer (EIS) allow us to measure the temperatures and emission measures from the resulting flare loops. We find clear evidence for heating over an extended period on the spatial scale of a single IRIS pixel. During the impulsive phase of this event, the intensities in each pixel for the Si iv 1402.770 Å, C ii 1334.535 Å, Mg ii 2796.354 Å, and O i 1355.598 Å emission lines are characterized by numerous small-scale bursts typically lasting 60 s or less. Redshifts are observed in Si iv, C ii, and Mg ii during the impulsive phase. Mg ii shows redshifts during the bursts and stationary emission at other times. The Si iv and C ii profiles, in contrast, are observed to be redshifted at all times during the impulsive phase. These persistent redshifts are a challenge for one-dimensional hydrodynamic models, which predict only short-duration downflows in response to impulsive heating. We conjecture that energy is being released on many small-scale filaments with a power-law distribution of heating rates.
DISSIPATIONAL VERSUS DISSIPATIONLESS GALAXY FORMATION AND THE DARK MATTER CONTENT OF GALAXIES

We examine two extreme models for the build-up of the stellar component of luminous elliptical galaxies. In one case, we assume the build-up of stars is dissipational, with centrally accreted gas radiating away its orbital and thermal energy; the dark matter (DM) halo will undergo adiabatic contraction and the central DM density profile will steepen. For the second model, we assume the central galaxy is assembled by a series of dissipationless mergers of stellar clumps that have formed far from the nascent galaxy. In order to be accreted, these clumps lose their orbital energy to the DM halo via dynamical friction, thereby heating the central DM and smoothing the DM density cusp. The central DM density profiles differ drastically between these models. For the isolated elliptical galaxy, NGC 4494, the central DM densities follow the power laws r−0.2 and r−1.7 for the dissipational and dissipationless models, respectively. By matching the dissipational and dissipationless models to observations of the stellar component of elliptical galaxies, we examine the relative contributions of dissipational and dissipationless mergers to the formation of elliptical galaxies and look for observational tests that will distinguish between these models. Comparisons to strong lensing brightest cluster galaxies yield median (M*/L)B ratios of 2.1 ± 0.8 and 5.2 ± 1.7 at z ≈ 0.39 for the dissipational and dissipationless models, respectively. For NGC 4494, the best-fit dissipational and dissipationless models have (M*/L)B = 2.97 and 3.96. Comparisons to expected stellar mass-to-light ratios from passive evolution and population syntheses appear to rule out a purely dissipational formation mechanism for the central stellar regions of giant elliptical galaxies.
Quantifying the uncertainties of chemical evolution studies II. Stellar yields

Context. Galactic chemical evolution models are useful tools for interpreting the large body of high-quality observational data on the chemical composition of stars and gas in galaxies that have become available in recent years. Aims. This is the second paper of a series that aims at quantifying the uncertainties in chemical evolution model predictions related to the underlying model assumptions. Specifically, it deals with the uncertainties due to the choice of the stellar yields. Methods. We adopted a widely used model for the chemical evolution of the Galaxy to test the effects of changing the stellar nucleosynthesis prescriptions on the predicted evolution of several chemical species. Up-to-date results from stellar evolutionary models were carefully taken into account. Results. We find that, except for a handful of elements whose nucleosynthesis in stars is well understood by now, large uncertainties still affect model predictions. This is especially true for the majority of the iron-peak elements, but also for much more abundant species such as carbon and nitrogen. The main causes of the mismatch we find among the outputs of different models assuming different stellar yields and among model predictions and observations are (i) the adopted location of the mass cut in models of type II supernova explosions; (ii) the adopted strength and extent of hot bottom burning in models of asymptotic giant branch stars; (iii) the neglection of the effects of rotation on the chemical composition of the stellar surfaces; (iv) the adopted rates of mass loss and of (v) nuclear reactions; and (vi) the different treatments of convection. Conclusions. Our results suggest that it is mandatory to include processes such as hot bottom burning in intermediate-mass stars and rotation in stars of all masses in accurate studies of stellar evolution and nucleosynthesis. In spite of their importance, both these processes still have to be better understood and characterized. As for massive stars, presupernova models computed with mass loss and rotation are available in the literature, but they still wait for a self-consistent coupling with the results of explosive nucleosynthesis computations.
DETECTION OF LYMAN-ALPHA EMISSION FROM A TRIPLY IMAGED z = 6.85 GALAXY BEHIND MACS J2129.4−0741

We report the detection of Lyα emission at ∼9538 Å in the Keck/DEIMOS and Hubble Space Telescope WFC3 G102 grism data from a triply imaged galaxy at z = 6.846 ± 0.001 behind galaxy cluster MACS J2129.4−0741. Combining the emission line wavelength with broadband photometry, line ratio upper limits, and lens modeling, we rule out the scenario that this emission line is [O ii] at z = 1.57. After accounting for magnification, we calculate the weighted average of the intrinsic Lyα luminosity to be ∼ 1.3 × 10 42 erg s − 1 and Lyα equivalent width to be 74 ± 15 Å. Its intrinsic UV absolute magnitude at 1600 Å is −18.6 ± 0.2 mag and stellar mass ( 1.5 ± 0.3 ) × 10 7 M ⊙ , making it one of the faintest (intrinsic L UV ∼ 0.14 L UV * ) galaxies with Lyα detection at z ∼ 7 to date. Its stellar mass is in the typical range for the galaxies thought to dominate the reionization photon budget at z ≳ 7 ; the inferred Lyα escape fraction is high ( ≳ 10 %), which could be common for sub-L* z ≳ 7 galaxies with Lyα emission. This galaxy offers a glimpse of the galaxy population that is thought to drive reionization, and it shows that gravitational lensing is an important avenue for probing the sub-L* galaxy population.
ON THE VERTICAL EQUILIBRIUM OF THE LOCAL GALACTIC DISK AND THE SEARCH FOR DISK DARK MATTER

Estimates of the dynamical surface mass density at the solar Galactocentric distance are commonly derived assuming that the disk is in vertical equilibrium with the Galactic potential. This assumption has recently been called into question, based on the claim that the ratio between the kinetic and the gravitational energy in such solutions is a factor of three larger than required if virial equilibrium is to hold. Here we show that this ratio between energies was overestimated and that the disk solutions are likely to be in virial equilibrium after all. We additionally demonstrate, using one-dimensional numerical simulations, that the disks are indeed in equilibrium. Hence, given the uncertainties, we find no reason to cast doubt on the steady-state solutions which are traditionally used to measure the matter density of the disk.
Improvement of magnetic hardness at finite temperatures : Ab initio disordered local-moment approach for YCo5

Temperature dependence of the magnetocrystalline anisotropy energy and magnetization of the prototypical rare-earth magnet YCo5 is calculated from first principles, utilizing the relativistic disordered local-moment approach. We discuss a strategy to enhance the finite-temperature anisotropy field by hole doping, paving the way for an improvement of the coercivity near room temperature or higher.
The dark side of galaxy colour: evidence from new SDSS measurements of galaxy clustering and lensing

The age matching model has recently been shown to predict correctly the luminosity L and g-r color of galaxies residing within dark matter halos. The central tenet of the model is intuitive: older halos tend to host galaxies with older stellar populations. In this paper, we demonstrate that age matching also correctly predicts the g-r color trends exhibited in a wide variety of statistics of the galaxy distribution for stellar mass M* threshold samples. In particular, we present new measurements of the galaxy two-point correlation function and the galaxy-galaxy lensing signal as a function of M* and g-r color from the Sloan Digital Sky Survey, and show that age matching exhibits remarkable agreement with these and other statistics of low-redshift galaxies. In so doing, we also demonstrate good agreement between the galaxy-galaxy lensing observed by SDSS and the signal predicted by abundance matching, a new success of this model. We describe how age matching is a specific example of a larger class of Conditional Abundance Matching models (CAM), a theoretical framework we introduce here for the first time. CAM provides a general formalism to study correlations at fixed mass between any galaxy property and any halo property. The striking successmore » of our simple implementation of CAM provides compelling evidence that this technique has the potential to describe the same set of data as alternative models, but with a dramatic reduction in the required number of parameters. CAM achieves this reduction by exploiting the capability of contemporary N-body simulations to determine dark matter halo properties other than mass alone, which distinguishes our model from conventional approaches to the galaxy-halo connection. « less
Acute, Non-Specific Low Back Pain Does Not Impair Isometric Deadlift Force or Electromyographic Excitation: A Cross-Sectional Study

Low back pain (LBP) is a leading cause of disability. The use of deadlift-based assessments in assessing LBP is becoming common in clinical settings, but these concepts have not been well studied. We sought to compare force and muscle excitation during isometric deadlifts in participants suffering from LBP versus asymptomatic controls. We also compared these outcomes for conventional versus hexagonal barbells. Sixteen adults with mild-to-moderate, acute, non-specific LBP and 19 controls performed maximal, isometric deadlifts while standing on a force plate using conventional and hexagonal barbells. Surface electromyographic signals were recorded from the upper trapezius, external oblique, erector spinae, vastus lateralis, and biceps femoris. Normalized peak force and peak rate of force development were similar for those with acute, non-specific LBP and controls. Surface electromyographic excitation was not different between groups, but was higher with the hexagonal barbell for the vastus lateralis and upper trapezius. Both groups felt equally safe and confident. In summary, the presence of acute, non-specific LBP did not impair peak and rapid force or muscle excitation. Hexagonal barbells may optimize knee extensor and trapezius activation. Deadlift-based force assessments appear safe and may be useful in the assessment of functional strength in patients with acute, non-specific LBP.
Safety and Efficacy of Three Variants of Canaloplasty with Phacoemulsification to Treat Open-Angle Glaucoma and Cataract: 12-Month Follow-Up

Background: A single-center prospective randomized observational study to compare three types of canaloplasty, i.e., ab externo (ABeC), minicanaloplasty (miniABeC) and ab interno, (ABiC) combined with cataract surgery in primary open-angle glaucoma (POAG) patients over 12 months. Methods: 48 POAG patients underwent one of three canaloplasty procedures: ABeC (16 eyes), miniABeC (16 eyes) or ABiC (16 eyes) or combined with phacoemulsification. Patients were assessed at baseline, at day 0–1–7 and at month 1–3–6–12. Successful treatment was defined as unmedicated IOP reduction ≥20%. Complete surgical success was defined as an IOP ≤ 15 mmHg without medications, and a qualified surgical success as IOP ≤ 15 mmHg with or without medications. Results: Pre-washout IOP median values (mmHg) were 17 (ABeC), 18 (miniABeC) and 17 (AbiC) and decreased at 12-month follow up postoperatively to 13 (p = 0.005), 13 (p = 0.004) and 14 (p = 0.008), respectively—successful treatment was achieved in approximately 100% of patients for ABeC and in 93.8% for both miniABeC and AbiC groups. Preoperatively, the median number of medications was 2.0 (range 1–3) (ABeC), 2.0 (1–3) (miniABeC) and 2.0 (0–4) (ABiC); 12-month post-operatively, all medications were withdrawn except in two patients (followed miniABeC and AbiC). Conclusions: The three variants of canaloplasty significantly reduced IOP and the number of medications in patients with mild to moderate POAG and gave no significant complications.
Low-Loss Ultrasound Transmission Through Waveguide From Double Parabolic Reflectors (DPLUS) for Thermal Ablation

In this paper, to advance acoustic waveguide transducers towards practical thermal ablation applications, we studied DPLUS (double parabolic reflectors wave-guided ultrasonic transducer) with a 1-m long (0.6-mm radius) and low-loss fused quartz thin waveguide working at the optimal frequency of 2.2 MHz, and the thermal effects to the tissue under different ultrasound exposure time. The measured vibration attenuation coefficient of the fused quartz thin waveguide is $\sim 0.0123$ dB/MHz/cm, and such low-loss characteristic is one of the keys of the studied DPLUS for realizing thermal ablation. Under the transmitted axial vibration velocity amplitude $v_{\mathrm {max}}$ at the thin waveguide tip of 1 m/s and the ultrasound exposure time of 1 s, 5 s, 10 s, 20 s, the measured temperature rises in the chicken breast tissue showed good agreements with the simulation results. Lesions were observed in the tissue under the exposure of 10 s, 20 s, and 30 s. The lesion size increases with the exposure time but the measured axial and lateral widths of the lesions were smaller than 2 mm. The presented results in this paper showed that thermal ablation was achieved by a m-range long thin-waveguide DPLUS which becomes an important progress of DPLUS towards practical MIT applications.
Matchings, coverings, and Castelnuovo-Mumford regularity

We show that the co-chordal cover number of a graph G gives an upper bound for the Castelnuovo-Mumford regularity of the associated edge ideal. Several known combinatorial upper bounds of regularity for edge ideals are then easy consequences of covering results from graph theory, and we derive new upper bounds by looking at additional covering results.
Antibacterial Properties of Polyphenols: Characterization and QSAR (Quantitative Structure–Activity Relationship) Models

Besides their established antioxidant activity, many phenolic compounds may exhibit significant antibacterial activity. Here, the effect of a large dataset of 35 polyphenols on the growth of 6 foodborne pathogenic or food-spoiling bacterial strains, three Gram-positive ones (Staphylococcus aureus, Bacillus subtilis, and Listeria monocytogenes) and three Gram-negative ones (Escherichia coli, Pseudomonas aeruginosa, and Salmonella Enteritidis), have been characterized. As expected, the effects of phenolic compounds were highly heterogeneous ranging from bacterial growth stimulation to antibacterial activity and depended on bacterial strains. The effect on bacterial growth of each of the polyphenols was expressed as relative Bacterial Load Difference (BLD) between a culture with and without (control) polyphenols at a 1 g L−1 concentration after 24 h incubation at 37°C. Reliable Quantitative Structure-Activity Relationship (QSAR) models were developed (regardless of polyphenol class or the mechanism of action involved) to predict BLD for E. coli, S. Enteritidis, S. aureus, and B. subtilis, unlike for L. monocytogenes and P. aeruginosa. L. monocytogenes was generally sensitive to polyphenols whereas P. aeruginosa was not. No satisfactory models predicting the BLD of P. aeruginosa and L. monocytogenes were obtained due to their specific and quite constant behavior toward polyphenols. The main descriptors involved in reliable QSAR models were the lipophilicity and the electronic and charge properties of the polyphenols. The models developed for the two Gram-negative bacteria (E. coli, S. Enteritidis) were comparable suggesting similar mechanisms of toxic action. This was not clearly observed for the two Gram-positive bacteria (S. aureus and B. subtilis). Interestingly, a preliminary evaluation by Microbial Adhesion To Solvents (MATS) measurements of surface properties of the two Gram-negative bacteria for which QSAR models were based on similar physico-chemical descriptors, revealed that MATS results were also quite similar. Moreover, the MATS results of the two Gram-positive bacterial strains S. aureus and B. subtilis for which QSARs were not based on similar physico-chemical descriptors also strongly differed. These observations suggest that the antibacterial activity of most of polyphenols likely depends on interactions between polyphenols and bacterial cells surface, although the surface properties of the bacterial strains should be further investigated with other techniques than MATS.