Miracle-dz/UniFAR-FTUs huggingface dataset:
PM2.5 exposures increased for the majority of Indians and a third of the global population during COVID-19 lockdowns: a residential biomass burning and environmental justice perspective

In response to the emergence of COVID-19 during Spring 2020, many countries implemented nationwide lockdowns and mandatory stay-at-home orders, which resulted in historically clean ambient air quality. However, in many parts of the world, biomass burning for cooking is a common activity, and in India specifically, it has been implicated as the leading contributor to indoor and ambient PM2.5, and its activity was not stopped and likely increased during lockdowns. Here, we first estimate baseline and lockdown PM2.5 exposures specific to India using new, nationwide time-use survey data coupled with fine-scale PM2.5 estimates within various microenvironments. We then extend this framework to estimate the population globally that will have experienced higher PM2.5 exposures during lockdowns, due both to an increase in residential biomass burning activity as well as the entire day being spent in the more-polluted home environment for biomass fuel using households. Sixty five percent of Indians, the percent that uses biomass fuels for cooking, were exposed to higher PM2.5 levels during the lockdown compared to their modeled baseline exposures, with the average modeled exposure increasing by 13% (95% distribution: 8–26) (from 116 (82–157) to 131 (104–170) μg m−3). We further leverage this exposure framework to present India’s most comprehensive, to date, PM2.5 exposure disparity and environmental justice assessment; although women were still exposed to the highest levels of PM2.5 during the lockdown (from 135 (91–191) μg m−3 baseline to 147 (106–200) μg m−3 during the lockdown; 8.8% (5–18) increase), the demographic groups that experienced the highest exposure increases were working-age men and school-age children, whose average modeled exposures increased by 24% (18–48) (from 88 (63–118) to 108 (94–139) μg m−3) and 18% (8–31) (from 98 (75–134) to 115 (98–145) μg m−3), respectively. Globally, we conservatively estimate that 34.5% (21–51) of the global population observed increased PM2.5 exposures during COVID-19 lockdowns, concentrated in low-income regions with high biomass usage. There have been a number of clean-cooking initiatives introduced in India and throughout the world to replace biomass cookstoves, but the finding that PM2.5 exposures increased for the majority of Indians and a third of the global population—driven largely by residential biomass burning for cooking—during a period of historically clean ambient air quality, re-emphasizes the urgent need to further address clean cooking interventions to reduce PM2.5 exposures and in turn improve health outcomes.
Conceptual design and simulation of a water Cherenkov muon veto for the XENON1T experiment

XENON is a dark matter direct detection project, consisting of a time projection chamber (TPC) filled with liquid xenon as detection medium. The construction of the next generation detector, XENON1T, is presently taking place at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy. It aims at a sensitivity to spin-independent cross sections of 2 · 10-47 c 2 for WIMP masses around 50 GeV2, which requires a background reduction by two orders of magnitude compared to XENON100, the current generation detector. An active system that is able to tag muons and muon-induced backgrounds is critical for this goal. A water Cherenkov detector of ∼ 10 m height and diameter has been therefore developed, equipped with 8 inch photomultipliers and cladded by a reflective foil. We present the design and optimization study for this detector, which has been carried out with a series of Monte Carlo simulations. The muon veto will reach very high detection efficiencies for muons (>99.5%) and showers of secondary particles from muon interactions in the rock (>70%). Similar efficiencies will be obtained for XENONnT, the upgrade of XENON1T, which will later improve the WIMP sensitivity by another order of magnitude. With the Cherenkov water shield studied here, the background from muon-induced neutrons in XENON1T is negligible.
21-cm signature of the first sources in the Universe: prospects of detection with SKA

Currently several low-frequency experiments are being planned to study the nature of the first stars using the redshifted 21-cm signal from the cosmic dawn and epoch of reionization. Using a one-dimensional radiative transfer code, we model the 21-cm signal pattern around the early sources for different source models, i.e., the metal-free Population III (PopIII) stars, primordial galaxies consisting of Population II (PopII) stars, mini-QSOs and high-mass X-ray binaries (HMXBs). We investigate the detectability of these sources by comparing the 21-cm visibility signal with the system noise appropriate for a telescope like the SKA1-low. Upon integrating the visibility around a typical source over all baselines and over a frequency interval of 16 MHz, we find that it will be possible to make a $\sim 9-\sigma$ detection of the isolated sources like PopII galaxies, mini-QSOs and HMXBs at $z \sim 15$ with the SKA1-low in 1000 hours. The exact value of the signal to noise ratio (SNR) will depend on the source properties, in particular on the mass and age of the source and the escape fraction of ionizing photons. The predicted SNR decreases with increasing redshift. We provide simple scaling laws to estimate the SNR for different values of the parameters which characterize the source and the surrounding medium. We also argue that it will be possible to achieve a SNR $\sim 9$ even in the presence of the astrophysical foregrounds by subtracting out the frequency-independent component of the observed signal. These calculations will be useful in planning 21-cm observations to detect the first sources.
Hydropower in the News: how Journalists do (not) Cover the Environmental and Socioeconomic Costs of Dams in Brazil

ABSTRACT Despite massive environmental impacts and socioeconomic risks, hydropower dams continue to be widely adopted and unquestioned in developing countries. This study analyzes two decades of mainstream media coverage of dams in Brazil, where two-thirds of energy consumption comes from hydropower. Through a content analysis of news articles published by the largest outlets in the country, we found coverage has relied on official and construction companies’ voices and focused on economic progress, bureaucracy, corruption, and partisan politics. News rarely covered the socio-environmental risks and impacts caused by dams or questioned the country’s reliance on hydropower. Overall, newspapers presented dams as highly necessary projects for national progress, conforming to a modernization-oriented mindset prevalent in newsrooms when it comes to coverage about energy. As a result, journalism has contributed to the invisibility of the struggles faced by people and the environment directly impacted by hydropower dams.
The unbearable (technical) unreliability of automated facial emotion recognition

Emotion recognition, and in particular acial emotion recognition (FER), is among the most controversial applications of machine learning, not least because of its ethical implications for human subjects. In this article, we address the controversial conjecture that machines can read emotions from our facial expressions by asking whether this task can be performed reliably. This means, rather than considering the potential harms or scientific soundness of facial emotion recognition systems, focusing on the reliability of the ground truths used to develop emotion recognition systems, assessing how well different human observers agree on the emotions they detect in subjects’ faces. Additionally, we discuss the extent to which sharing context can help observers agree on the emotions they perceive on subjects’ faces. Briefly, we demonstrate that when large and heterogeneous samples of observers are involved, the task of emotion detection from static images crumbles into inconsistency. We thus reveal that any endeavour to understand human behaviour from large sets of labelled patterns is over-ambitious, even if it were technically feasible. We conclude that we cannot speak of actual accuracy for facial emotion recognition systems for any practical purposes.
Lessons from supersymmetry: "Instead-of-Confinement" Mechanism

We review physical scenarios in different vacua of N=2 supersymmetric QCD deformed by the mass term \mu for the adjoint matter. This deformation breaks supersymmetry down to N=1 and, at large \mu, the theory flows to N=1 SQCD. We focus on dynamical scenarios which can serve as prototypes of what we observe in real-world QCD. The so-called r=N vacuum is especially promising in this perspective. In this vacuum an "instead-of-confinement" phase was identified previously, which is qualitatively close to the conventional QCD confinement: the quarks and gauge bosons screened at weak coupling, at strong coupling evolve into monopole-antimonopole pairs confined by non-Abelian strings. We review genesis of this picture.
UHECR bounds on Lorentz violation in the photon sector

The aim of this brief review is to present a case study of how astrophysics data can be used to get bounds on Lorentz-violating parameters. For this purpose, a particularly simple Lorentz-violating modification of the Maxwell theory of photons is considered, which maintains gauge invariance, CPT, and renormalization. With a standard spin-one-half Dirac particle minimally coupled to this nonstandard photon, the resulting modified-quantum-electrodynamics model involves nineteen dimensionless "deformation parameters. " Ten of these parameters lead to birefringence and are already tightly constrained by astrophysics. New bounds on the remaining nine nonbirefringent parameters have been obtained from the inferred absence of vacuum Cherenkov radiation in ultrahigh-energy-cosmic-ray (UHECR) events. The resulting astrophysics bounds improve considerably upon current laboratory bounds and the implications of this "null experiment" may be profound, both for elementary particle physics and cosmology.
Epidemiological profile of the level of physical activity of undergraduate and postgraduate university professors

OBJECTIVE: To verify the anthropometric, professional, pain and physical activity characteristics of university professors working in undergraduate and graduate courses: a pilot study. METHODS: Twenty teachers from a Higher Education Institution were evaluated, which were divided into two groups: group of undergraduate teachers (GPG, n = 10); group of postgraduate teachers (GPPG, n = 10). The assessment process was divided into: step 1, anthropometric and professional characterization; step 2, assessment of pain / discomfort using the Nordic questionnaire and step 3, assessment of the physical activity level, using the questionnaire: International Physical Activity Questionnaire-IPAC. RESULTS: The GPPG showed 90% for females, 70% of whom were married with overweight BMI. Teaching time was 10 years. The practice of physical activity was 30 to 60 minutes. Hypercholesterolemia was found in 90% of cases. Discomfort remained at 90% in the lower back. The IPAC was 20% sedentary. In GPG, on the other hand, 80% can be observed for females, 70% single with 90% overweight. The teaching time was 10 years. Physical activity was 10 to 15 minutes. The prevalent disease was hypercholesterolemia. Discomfort was 90% in the lumbar region and 80% in the neck and shoulder. The IPAC was 60% sedentary. CONCLUSION: It can be concluded that undergraduate teachers have more neck and shoulder pain, are overweight with a higher level of physical inactivity while graduate teachers have more lumbar pain with ideal weight and greater practice of physical activity.
NON-NEUTRALIZED ELECTRIC CURRENT PATTERNS IN SOLAR ACTIVE REGIONS: ORIGIN OF THE SHEAR-GENERATING LORENTZ FORCE

Using solar vector magnetograms of the highest available spatial resolution and signal-to-noise ratio, we perform a detailed study of electric current patterns in two solar active regions (ARs): a flaring/eruptive and a flare-quiet one. We aim to determine whether ARs inject non-neutralized (net) electric currents in the solar atmosphere, responding to a debate initiated nearly two decades ago that remains inconclusive. We find that well-formed, intense magnetic polarity inversion lines (PILs) within ARs are the only photospheric magnetic structures that support significant net current. More intense PILs seem to imply stronger non-neutralized current patterns per polarity. This finding revises previous works that claim frequent injections of intense non-neutralized currents by most ARs appearing in the solar disk but also works that altogether rule out injection of non-neutralized currents. In agreement with previous studies, we also find that magnetically isolated ARs remain globally current-balanced. In addition, we confirm and quantify the preference of a given magnetic polarity to follow a given sense of electric currents, indicating a dominant sense of twist in ARs. This coherence effect is more pronounced in more compact ARs with stronger PILs and must be of sub-photospheric origin. Our results yield a natural explanation of the Lorentz force, invariably generating velocity and magnetic shear along strong PILs, thus setting a physical context for the observed pre-eruption evolution in solar ARs.
Structure formation in inhomogeneous Early Dark Energy models

We study the impact of Early Dark Energy fluctuations in the linear and non-linear regimes of structure formation. In these models the energy density of dark energy is non-negligible at high redshifts and the fluctuations in the dark energy component can have the same order of magnitude of dark matter fluctuations. Since two basic approximations usually taken in the standard scenario of quintessence models, that both dark energy density during the matter dominated period and dark energy fluctuations on small scales are negligible, are not valid in such models, we first study approximate analytical solutions for dark matter and dark energy perturbations in the linear regime. This study is helpful to find consistent initial conditions for the system of equations and to analytically understand the effects of Early Dark Energy and its fluctuations, which are also verified numerically. In the linear regime we compute the matter growth and variation of the gravitational potential associated with the Integrated Sachs-Wolf effect, showing that these observables present important modifications due to Early Dark Energy fluctuations, though making them more similar to the ΛCDM model. We also make use of the Spherical Collapse model to study the influence of Early Dark Energy fluctuations in the nonlinear regime of structure formation, especially on δc parameter, and their contribution to the halo mass, which we show can be of the order of 10%. We finally compute how the number density of halos is modified in comparison to the ΛCDM model and address the problem of how to correct the mass function in order to take into account the contribution of clustered dark energy. We conclude that the inhomogeneous Early Dark Energy models are more similar to the ΛCDM model than its homogeneous counterparts.
PERSPECTIVES ON INTRACLUSTER ENRICHMENT AND THE STELLAR INITIAL MASS FUNCTION IN ELLIPTICAL GALAXIES

Stars formed in galaxy cluster potential wells must be responsible for the high level of enrichment measured in the intracluster medium (ICM); however, there is increasing tension between this truism and the parsimonious assumption that the stars in the generally old population studied optically in cluster galaxies emerged from the same formation sites at the same epochs. We construct a phenomenological cluster enrichment model to demonstrate that ICM elemental abundances are underestimated by a factor >2 for standard assumptions about the stellar population—a discrepancy we call the “cluster elemental abundance paradox. ” Recent evidence of an elliptical galaxy initial mass function (IMF) skewed to low masses deepens the paradox. We quantify the adjustments to the star formation efficiency and IMF, and Type Ia supernovae (SNIa) production efficiency, required to resolve this while being consistent with the observed ICM abundance pattern. The necessary enhancement in metal enrichment may, in principle, originate in the observed stellar population if a larger fraction of stars in the supernova-progenitor mass range form from an IMF that is either bottom-light or top-heavy, with the latter in some conflict with observed ICM abundance ratios. Other alternatives that imply more modest revisions to the IMF, mass return and remnant fractions, and primordial fraction, posit an increase in the fraction of 3–8 M☉ stars that explode as SNIa or assume that there are more stars than conventionally thought—although the latter implies a high star formation efficiency. We discuss the feasibility of these various solutions and the implications for the diversity of star formation in the universe, the process of elliptical galaxy formation, and the origin of this “hidden” source of ICM metal enrichment.
PLANETARY AND OTHER SHORT BINARY MICROLENSING EVENTS FROM THE MOA SHORT-EVENT ANALYSIS

We present the analysis of four candidate short-duration binary microlensing events from the 2006–2007 MOA Project short-event analysis. These events were discovered as a by-product of an analysis designed to find short-timescale single-lens events that may be due to free-floating planets. Three of these events are determined to be microlensing events, while the fourth is most likely caused by stellar variability. For each of the three microlensing events, the signal is almost entirely due to a brief caustic feature with little or no lensing attributable mainly to the lens primary. One of these events, MOA-bin-1, is due to a planet, and it is the first example of a planetary event in which the stellar host is only detected through binary microlensing effects. The mass ratio and separation are q = (4.9 ± 1.4) × 10−3 and s = 2.10 ± 0.05, respectively. A Bayesian analysis based on a standard Galactic model indicates that the planet, MOA-bin-1Lb, has a mass of mp = 3.7 ± 2.1 MJup and orbits a star of at a semimajor axis of AU. This is one of the most massive and widest separation planets found by microlensing. The scarcity of such wide-separation planets also has implications for interpretation of the isolated planetary mass objects found by this analysis. If we assume that we have been able to detect wide-separation planets with an efficiency at least as high as that for isolated planets, then we can set limits on the distribution of planets in wide orbits. In particular, if the entire isolated planet sample found by Sumi et al. consists of planets bound in wide orbits around stars, we find that it is likely that the median orbital semimajor axis is >30 AU.
CHEMICAL EVOLUTION OF THE LARGE MAGELLANIC CLOUD

We adopt a new chemical evolution model for the Large Magellanic Cloud (LMC) and thereby investigate its past star formation and chemical enrichment histories. The delay time distribution of Type Ia supernovae recently revealed by Type Ia supernova surveys is incorporated self-consistently into the new model. The principle results are summarized as follows. The present gas mass fraction and stellar metallicity as well as the higher [Ba/Fe] in metal-poor stars at [Fe/H] < −1.5 can be more self-consistently explained by models with steeper initial mass functions. The observed higher [Mg/Fe] (⩾0.3) at [Fe/H] ∼ −0.6 and higher [Ba/Fe] (>0.5) at [Fe/H] ∼ −0.3 could be due to significantly enhanced star formation about 2 Gyr ago. The observed overall [Ca/Fe]–[Fe/H] relation and remarkably low [Ca/Fe] (< − 0.2) at [Fe/H] > −0.6 are consistent with models with short-delay supernova Ia and with the more efficient loss of Ca possibly caused by an explosion mechanism of Type II supernovae. Although the metallicity distribution functions do not show double peaks in the models with a starburst about 2 Gyr ago, they show characteristic double peaks in the models with double starbursts ∼200 Myr and ∼2 Gyr ago. The observed apparent dip of [Fe/H] around ∼1.5 Gyr ago in the age–metallicity relation can be reproduced by models in which a large amount (∼109 M☉) of metal-poor ([Fe/H] < −1) gas can be accreted onto the LMC.
Non‐universality of halo profiles and implications for dark matter experiments

We explore the cosmological halo-to-halo scatter of the distribution of mass within dark matter haloes utilizing a well-resolved statistical sample of clusters from the cosmological Millennium Simulation. We find that at any radius, the spherically averaged dark matter density of a halo (corresponding to the ‘smooth component’) and its logarithmic slope are well described by a Gaussian probability distribution. At small radii (within the scale radius), the density distribution is fully determined by the measured Gaussian distribution in halo concentrations. The variance in the radial distribution of mass in dark matter haloes is important for the interpretation of direct and indirect dark matter detection efforts. The scatter in mass profiles imparts approximately a 25 per cent cosmological uncertainty in the dark matter density at the Solar neighbourhood and a factor of ∼3 uncertainty in the expected Galactic dark matter annihilation flux. The aggregate effect of halo-to-halo profile scatter leads to a small (few per cent) enhancement in dark matter annihilation background if the Gaussian concentration distribution holds for all halo masses versus a 10 per cent enhancement under the assumption of a lognormal concentration distribution. The Gaussian nature of the cluster profile scatter implies that the technique of ‘stacking’ haloes to improve signal-to-noise ratio should not suffer from bias.
Thermalisation of a quantum system from first principles

Why is thermalisation a universal phenomenon? How does a quantum system reach thermodynamical equilibrium? These questions are not new, dating even from the very birth of quantum theory and have been the subject of a renewed interest over the two last decades (see for instance the review in Eisert et al, Nature Physics 2015). In this work, we propose a universal model demonstrating that thermalisation of a small quantum system is an emergent property of the unitary evolution under a Schrodinger equation of a larger composite system, whose initial state can be arbitrary. We show that the origin of universality lies in the phenomenon of 'measure concentration', which provides self-averaging properties for the reduced density matrix characterizing the state of the small subsystem. Using our framework, we focus on the asymptotic state at long times and consider its stationary properties. In typical macroscopic conditions, we recover the canonical state and the Boltzmann distribution well known from statistical thermodynamics. This findings lead us to propose an alternative and more general definition of the canonical partition function which also allow us to describe non thermal stationary states.