Miracle-dz/UniFAR-FTUs huggingface dataset:
ON UNDERSTANDING THE NATURE OF COLLISIONS OF CORONAL MASS EJECTIONS OBSERVED BY STEREO

We attempt to understand the collision characteristics of two coronal mass ejections (CMEs) launched successively from the Sun on 2013 October 25. The estimated kinematics, from three-dimensional (3D) reconstruction techniques applied to observations of CMEs by the SECCHI/Coronagraphic (COR) and Heliospheric Imagers, reveal their collision around 37 from the Sun. In the analysis, we take into account the propagation and expansion speeds, impact direction, and angular size as well as the masses of the CMEs. These parameters are derived from imaging observations, but may suffer from large uncertainties. Therefore, by adopting head-on as well as oblique collision scenarios, we have quantified the range of uncertainties involved in the calculation of the coefficient of restitution for expanding magnetized plasmoids. We show that the large expansion speed of the following CME compared with that of the preceding CME results in a higher probability of super-elastic collision. We also infer that a relative approaching speed of the CMEs lower than the sum of their expansion speeds increases the chance of a super-elastic collision. The analysis under reasonable errors in the observed parameters of the CME reveals a larger probability of occurrence of an inelastic collision for the selected CMEs. We suggest that the collision nature of two CMEs should be discussed in 3D, and the calculated value of the coefficient of restitution may suffer from a large uncertainty.
Line-driven winds and the UV turnover in AGN accretion discs

AGN SEDs generally show a turnover at lambda 1000A, implying a maximal accretion disc (AD) temperature of T_max~50,000K. Massive O stars display a similar T_max, associated with a sharp rise in a line driven mass loss Mdot_wind with increasing surface temperature. AGN AD are also characterized by similar surface gravity to massive O stars. The Mdot_wind of O stars reaches ~10^-5 Msun/year. Since the surface area of AGN AD can be 10^6 larger, the implied Mdot_wind in AGN AD can reach the accretion rate Mdot. A rise to Mdot_wind Mdot towards the AD center may therefore set a similar cap of T_max~50,000K. To explore this idea, we solve the radial structure of an AD with a mass loss term, and calculate the implied AD emission using the mass loss term derived from observations of O stars. We find that Mdot_wind becomes comparable to Mdot typically at a few 10s of GM/c^2. Thus, the standard thin AD solution is effectively truncated well outside the innermost stable orbit. The calculated AD SED shows the observed turnover at lambda~1000A, which is weakly dependent on the AGN luminosity and black hole mass. The AD SED is generally independent of the black hole spin, due to the large truncation radius. However, a cold AD (low Mdot, high black hole mass) is predicted to be windless, and thus its SED should be sensitive to the black hole spin. The accreted gas may form a hot thick disc with a low radiative efficiency inside the truncation radius, or a strong line driven outflow, depending on its ionization state.
The D-material universe

In a previous publication by some of the authors (N.E.M., M.S. and M.F.Y.), we have argued that the ``D-material universe'', that is a model of a brane world propagating in a higher-dimensional bulk populated by collections of D-particle stringy defects, provides a model for the growth of large-scale structure in the universe via the vector field in its spectrum. The latter corresponds to D-particle recoil velocity excitations as a result of the interactions of the defects with stringy matter and radiation on the brane world. In this article, we first elaborate further on the results of the previous study on the galactic growth era and analyse the circumstances under which the D-particle recoil velocity fluid may ``mimic'' dark matter in galaxies. A lensing phenomenology is also presented for some samples of galaxies, which previously were known to provide tension for modified gravity (TeVeS) models. The current model is found in agreement with these lensing data. Then we discuss a cosmic evolution for the D-material universe by analysing the conditions under which the late eras of this universe associated with large-scale structure are connected to early epochs, where inflation takes place. It is shown that inflation is induced by dense populations of D-particles in the early universe, with the rôle of the inflaton field played by the condensate of the D-particle recoil-velocity fields under their interaction with relativistic stringy matter, only for sufficiently large brane tensions and low string mass scales compared to the Hubble scale. On the other hand, for large string scales, where the recoil-velocity condensate fields are weak, inflation cannot be driven by the D-particle defects alone. In such cases inflation may be driven by dilaton (or other moduli) fields in the underlying string theory.
Health and the intention to retire: exploring the moderating effects of human resources practices

Abstract Although health is among the strongest predictors of retirement timing, organizational effects on this relationship are largely unknown. Based on the theory of work adjustment and socioemotional selectivity theory, this study explores the role of human resources practices in the relation between older employees’ health and retirement intentions—specifically, their preferred retirement age and their intention to engage in late-career employment after being eligible for pension. Three groups of practices are distinguished: individual development practices (e.g. life-long learning and career development), practices tailoring the transition to retirement (e.g. phased retirement), and practices allowing to continue working in later life (e.g. individualized employment forms). We tested our model with multilevel data from 556 older employees and 661 managers from 101 organizations. Results suggest that healthy employees intend to retire later, if individual development practices are stronger pronounced in the organization. In addition, the positive relation between health and the intention to engage in late-career employment was stronger in organizations that provide more opportunities to continue working. Our findings contribute to a better understanding of retirement intentions and offer practical implications to shape later-life work to the benefit of both organizations and employees.
Unified Dark Matter scalar field models with fast transition

We investigate the general properties of Unified Dark Matter (UDM) scalar field models with Lagrangians with a non-canonical kinetic term, looking specifically for models that can produce a fast transition between an early Einstein-de Sitter CDM-like era and a later Dark Energy like phase, similarly to the barotropic fluid UDM models in JCAP01(2010)014. However, while the background evolution can be very similar in the two cases, the perturbations are naturally adiabatic in fluid models, while in the scalar field case they are necessarily non-adiabatic. The new approach to building UDM Lagrangians proposed here allows to escape the common problem of the fine-tuning of the parameters which plague many UDM models. We analyse the properties of perturbations in our model, focusing on the the evolution of the effective speed of sound and that of the Jeans length. With this insight, we can set theoretical constraints on the parameters of the model, predicting sufficient conditions for the model to be viable. An interesting feature of our models is that what can be interpreted as wDE can be < −1 without violating the null energy conditions.
Geography Matters: Explaining Education Inequalities of Latvian Children in England

This article explores the issue of “geography of education” focusing on the pivotal contribution of place to one’s education. The geographic location of schools and the administrative organisation of local authorities that are responsible for state schools in England create sociospatial inequalities that are associated with individual life‐course trajectories and can contribute to the intergenerational transfer of disadvantage. This article focuses on Latvian migrant families for whom better status often can be achieved through being included in the education system of the country. Therefore, the educational achievement of the children who speak Latvian at home but live and attend schools in England is the main focus of this article. The academic attainment of these children is well below not only the national average across all levels of compulsory education but also compared to both monolingual English speakers and all pupils speaking English as an additional language. The article provides evidence that in addition to the sociodemographic individual and family‐level factors geography also plays a significant role in explaining the educational achievement gaps. As the descriptive quantitative analysis of the geographical and educational data indicates, Latvian children are disproportionally present in local authorities where there is a relatively high proportion of low‐quality schools, a higher‐than‐average proportion of individuals with low qualifications and those in low‐qualified jobs.
AOX1a Expression in Arabidopsis thaliana Affects the State of Chloroplast Photoprotective Systems under Moderately High Light Conditions

Alternative oxidase (AOX) in the mitochondrial electron transport chain is considered important for sustaining photosynthesis under high light conditions. Here, we examined the effects of the AOX pathway on the state of chloroplast photoprotective systems. Arabidopsis thaliana plants (4 weeks old), comprising three genotypes (wild type [WT], overexpressing [XX-2] and antisense [AS-12] lines for AOX1a), were exposed to moderately high light conditions (MHL, 400 μmol m−2 s−1) in a short-term experiment (8 h). After 8 h of MHL, the WT and XX-2 plants showed stable non-photochemical quenching (qN) and violaxanthin cycle activity. Antisense plants displayed the lowest level of qN and a lower de-epoxidation state (DEPS) relative to plants of the same line after 4–6 h MHL, as well as compared to WT and XX-2 plants after 8 h MHL. The decline in DEPS in AS-12 plants was attributed to an insufficient violaxanthin de-epoxidase activity, which in turn was associated with a decrease in reduced ascorbate levels in the chloroplasts and leaves. Simultaneously, gene expression and the activity of ascorbate peroxidase in the antisense line increased after 8 h of MHL, supporting the compensatory effect of the antioxidant system when AOX1a expression is suppressed. This study emphasizes the role played by AOX in modulating the photoprotection processes and in the maintenance of relationships between mitochondria and chloroplasts by influencing ascorbate content.
Quasideterminant solutions of the generalized Heisenberg magnet model

In this paper we present the Darboux transformation for the generalized Heisenberg magnet (GHM) model based on the general linear Lie group GL(n) and construct multi-soliton solutions in terms of quasideterminants. Further we relate the quasideterminant multi-soliton solutions obtained by means of Darboux transformation with those obtained by the dressing method. We also discuss the model based on the Lie group SU(n) and obtain explicit soliton solutions of the model based on SU(2).
Identifying and analyzing effects of interdependencies on construction contractor payment risks

Literature suggests that interdependencies may expose construction contractors to payment risks. However, prior research has tended to assume a disconnected perspective, which ignores the interdependence effect. To bridge this gap, a network of incompatible practices was built using judgments from subject matter experts in payment dispute cases in Kenya. After that, social network analysis (SNA) techniques such as Eigenvector and Lambda partitioning were used to analyze it. Ten interdependencies that expose contractors to payment risk were identified. The interdependence between the payment upon verified performance and the failure to match the work done with the amounts paid initiates and transmits most of these risks. In line with the power-law principle, fewer than 20% initiate and transmit more than 80% of the risks. This study demonstrates how economizing strategies can influence the choice of practices, complement blockchain decentralization measures, and improve the analysis of payment dispute cases.
MODELING VERY LONG BASELINE INTERFEROMETRIC IMAGES WITH THE CROSS-ENTROPY GLOBAL OPTIMIZATION TECHNIQUE

We present a new technique for obtaining model fittings to very long baseline interferometric images of astrophysical jets. The method minimizes a performance function proportional to the sum of the squared difference between the model and observed images. The model image is constructed by summing Ns elliptical Gaussian sources characterized by six parameters: two-dimensional peak position, peak intensity, eccentricity, amplitude, and orientation angle of the major axis. We present results for the fitting of two main benchmark jets: the first constructed from three individual Gaussian sources, the second formed by five Gaussian sources. Both jets were analyzed by our cross-entropy technique in finite and infinite signal-to-noise regimes, the background noise chosen to mimic that found in interferometric radio maps. Those images were constructed to simulate most of the conditions encountered in interferometric images of active galactic nuclei. We show that the cross-entropy technique is capable of recovering the parameters of the sources with a similar accuracy to that obtained from the very traditional Astronomical Image Processing System Package task IMFIT when the image is relatively simple (e.g., few components). For more complex interferometric maps, our method displays superior performance in recovering the parameters of the jet components. Our methodology is also able to show quantitatively the number of individual components present in an image. An additional application of the cross-entropy technique to a real image of a BL Lac object is shown and discussed. Our results indicate that our cross-entropy model-fitting technique must be used in situations involving the analysis of complex emission regions having more than three sources, even though it is substantially slower than current model-fitting tasks (at least 10,000 times slower for a single processor, depending on the number of sources to be optimized). As in the case of any model fitting performed in the image plane, caution is required in analyzing images constructed from a poorly sampled (u, v) plane.
Disk transport rates from Ti isotopic signatures of refractory inclusions

The early solar system was a dynamic period during which the formation of early solids set into motion the process of planet building. Although both astrophysical observations and theoretical modeling demonstrate the presence of widespread transport of material, we lack concrete quantitative constraints on timings, distances, and mechanisms thereof. To trace these transport processes, one needs objects of known early formation times and these objects would need to be distributed throughout parent bodies with known accretion times and distances. Generally, these criteria are met by “regular” (i.e., non–fractionated and unidentified nuclear and excluding hibonite‐rich) Ca‐Al‐rich inclusions (CAIs) as these objects formed very early and close to the young Sun and contain distinctive nucleosynthetic isotope anomalies that permit provenance tracing. However, nucleosynthetic isotopic signatures of such refractory inclusions have so far primarily been analyzed in chondritic meteorites that formed within ~4 AU from the Sun. Here, we investigate Ti isotopic signatures of four refractory inclusions from the ungrouped carbonaceous chondrite WIS 91600 that was previously suggested to have formed beyond ~10 AU from the Sun. We show that these inclusions exhibit correlated excesses in 50Ti and 46Ti and lack large Ti isotopic anomalies that would otherwise be indicative of more enigmatic refractory materials with unknown formation ages. Instead, these isotope systematics suggest the inclusions to be genetically related to regular CAIs commonly found in other chondrites that have a broadly known formation region and age. Collectively, this implies that a common population of CAIs was distributed over the inner ~10 AU within ~3.5 Myr, yielding an average (minimum) speed for the transport of millimeter‐scale material in the early solar system of ~1 cm s−1.
TIMASSS: the IRAS16293-2422 millimeter and submillimeter spectral survey: tentative detection of deuterated methyl formate (DCOOCH3)

Context. High deuterium fractionation is observed in various types of environments such as prestellar cores, hot cores, and hot corinos. It has proven to be an efficient probe for studying the physical and chemical conditions of these environments. The study of the deuteration of different molecules helps us to understand their formation. This is especially interesting for complex molecules like methanol and bigger molecules for which it may allow differentiation of gas-phase and solid-state formation pathways. Aims. Methanol exhibits a high deuterium fractionation in hot corinos. Since CH 3 OH is thought to be a precursor of methyl formate we expect that deuterated methyl formate is produced in such environments. We searched for the singly-deuterated isotopologue of methyl formate, DCOOCH 3 , in IRAS 16293-2422, a hot corino well-known for its high degree of methanol deuteration. Methods. We used the IRAM/JCMT unbiased spectral survey of IRAS 16293-2422, which allowed us to search for the DCOOCH 3 rotational transitions within the survey spectral range (80-280 GHz, 328-366 GHz). The expected emission of deuterated methyl formate is modelled at LTE and compared with the observations. Results. We have tentatively detected DCOOCH 3 in the protostar IRAS 16293-2422. We assign eight lines detected in the IRAM survey to DCOOCH3. Three of these lines are affected by blending problems, and one is affected by calibration uncertainties; nevertheless, the LTE emission model is compatible with the observations. A simple LTE modelling of the two cores in IRAS 16293-2422, based on a previous interferometric study of HCOOCH 3 , allows us to estimate the amount of DCOOCH 3 in IRAS 16293-2422. Adopting an excitation temperature of 100 K and a source size of 2"and 1"5 for the A and B cores, respectively, we find that N A,DCOOCH3 = N B,DCOOCH3 ∼6 × 10 14 cm ―2 . The derived deuterium fractionation is ∼ 15%, consistent with values for other deuterated species in this source and much greater than expected from the deuterium cosmic abundance. Conclusions. If its tentative detection is confirmed, DCOOCH 3 should now be considered in theoretical models that study complex molecule formation and their deuteration mechanisms. Experimental work is also needed to investigate the different chemical routes leading to the formation of deuterated methyl formate.
AN EMPIRICAL CONNECTION BETWEEN THE ULTRAVIOLET COLOR OF EARLY-TYPE GALAXIES AND THE STELLAR INITIAL MASS FUNCTION

Using new UV magnitudes for a sample of early-type galaxies (ETGs) with published stellar mass-to-light ratios, ϒ*, we find a correlation between UV color and ϒ* that is tighter than those previously identified between ϒ* and either the central stellar velocity dispersion, metallicity, or alpha enhancement. The sense of the correlation is that galaxies with larger ϒ* are bluer in the UV. We conjecture that differences in the lower mass end of the stellar initial mass function (IMF) are related to the nature of the extreme horizontal branch populations that are generally responsible for the UV flux in ETGs. If so, then UV color can be used to identify ETGs with particular IMF properties and to estimate ϒ*.
On the continued fraction expansion of absolutely normal numbers

We construct an absolutely normal number whose continued fraction expansion is normal in the sense that it contains all finite patterns of partial quotients with the expected asymptotic frequency as given by the Gauss-Kuzmin measure. The construction is based on ideas of Sierpinski and uses a large deviations theorem for sums of mixing random variables.
Theory of interfacial plasmon-phonon scattering in supported graphene

One of the factors limiting electron mobility in supported graphene is remote phonon scattering. We formulate the theory of the coupling between graphene plasmon and substrate surface polar phonon (SPP) modes, and find that it leads to the formation of interfacial plasmon-phonon (IPP) modes, from which the phenomena of dynamic anti-screening and screening of remote phonons emerge. The remote phonon-limited mobilities for SiO$_{2}$, HfO$_{2}$, h-BN and Al$_{2}$O$_{3}$ substrates are computed using our theory. We find that h-BN yields the highest peak mobility, but in the practically useful high-density range the mobility in HfO$_{2}$-supported graphene is high, despite the fact that HfO$_{2}$ is a high-$\kappa$ dielectric with low-frequency modes. Our theory predicts that the strong temperature dependence of the total mobility effectively vanishes at very high carrier concentrations. The effects of polycrystallinity on IPP scattering are also discussed.
A measure on the set of compact Friedmann–Lemaître–Robertson–Walker models

Compact, flat Friedmann–Lemaître–Robertson–Walker (FLRW) models have recently regained interest as a good fit to the observed cosmic microwave background temperature fluctuations. However, it is generally thought that a globally, exactly flat FLRW model is theoretically improbable. Here, in order to obtain a probability space on the set F of compact, comoving, 3-spatial sections of FLRW models, a physically motivated hypothesis is proposed, using the density parameter Ω as a derived rather than fundamental parameter. We assume that the processes that select the 3-manifold also select a global mass-energy and a Hubble parameter. The requirement that the local and global values of Ω are equal implies a range in Ω that consists of a single real value for any 3-manifold. Thus, the obvious measure over F is the discrete measure. Hence, if the global mass-energy and Hubble parameter are a function of 3-manifold choice among compact FLRW models, then probability spaces parametrized by Ω do not, in general, give a zero probability of a flat model. Alternatively, parametrization by a spatial size parameter, the injectivity radius rinj, suggests the Lebesgue measure. In this case, the probability space over the injectivity radius implies that flat models occur almost surely (a.s.), in the sense of probability theory, and non-flat models a.s. do not occur.