Miracle-dz/UniFAR-FTUs huggingface dataset:
A forest type-specific threshold method for improving forest disturbance and agent attribution mapping

ABSTRACT Detecting forest disturbances and attributing their contributing agents with Landsat time series (LTS) images has advanced substantially in recent years; however, whether different forest types require individual disturbance indices or specific disturbance thresholds to accurately map forest disturbances and their causes over a vast region remains limited known. This study investigated the effectiveness of six spectral indices (SIs) and two threshold methods (a forest-specific threshold and a common threshold) for detecting forest disturbances among four forest types, namely, evergreen broad-leaved forests (EBFs), cold-temperate evergreen needle-leaved forests (CENFs), and subtropical evergreen needle-leaved forests mainly dominated by Pinus yunnanensis (SENF1) or Pinus kesiya (SENF2), across Yunnan Province with the Landsat-based Detection of Trends in Disturbance and Recovery (LandTrendr) algorithm and yearly Landsat time series (LTS) recorded from 1990 to 2020. A random forest (RF) model was applied to classify the forest disturbance agents from aggregated patches of disturbed forest pixels. The results indicated that the normalized burn ratio (NBR) outperformed the five other SIs and achieved consistently high overall accuracies (OAs; 93.04%±0.17% to 96.09%±0.28%) when mapping forest disturbances across all four forest types. The forest-specific NBR disturbance thresholds led to considerable increases in overall (0.14–3.92%), producer (0.25–13.47%) and user accuracies (0.88–3.01%). The total mapped area of disturbed forest was 9831.48 km2 (5.31%), of which approximately 79% occurred in the EBF and SENF1 distribution areas. Forest disturbances were predominantly caused by wildfires in CENF and SENF1 and by commodity-driven plantations in EBF and SENF2; these two agents together contributed approximately 93.15% of the forest disturbances in Yunnan province. These findings highlight that the optimal selection of SIs and forest-specific disturbance thresholds can significantly improve forest disturbance detection performance.
Electromagnetic Waves in Chiral and Bi-Isotropic Media

For scientists, research engineers, physicists and postgraduate students, this work introduces the essential aspects of electromagnetic waves in chiral and bi-isotropic media, to give the practical working knowledge necessary for new application development. It includes sections on effective methods of measurement, how chiral and BI media affect electromagnetic fields and wave propagation, and how to apply the theory to basic problems in waveguide, antenna and scattering analysis.
An unexpected drop in the magnetic field of the X-ray pulsar V0332+53 after the bright outburst occurred in 2015

How the accreted mass settling on the surface of a neutron star affects the topology of the magnetic field and how the secular evolution of the binary system depends on the magnetic field change is still an open issue. We report evidence for a clear drop in the observed magnetic field in the accreting pulsar V0332+53 after undergoing a bright 3-month long X-ray outburst. We determine the field from the position of the fundamental cyclotron line in its X-ray spectrum and relate it to the luminosity. For equal levels of luminosity, in the declining phase we measure a systematically lower value of the cyclotron line energy with respect to the rising phase. This results in a drop of ~1.7 x 10^11 G of the observed field between the onset and the end of the outburst. The settling of the accreted plasma onto the polar cap seems to induce a distortion of the magnetic field lines weakening their intensity along the accretion columns. Therefore the dissipation rate of the magnetic field could be much faster than previously estimated, unless the field is able to restore its original configuration on a time-scale comparable with the outbursts recurrence time.
Valuation of cultural ecosystem services in urban parks with different social contexts in the city of Recife (PE), Brazil

The accelerated process of urbanization of the planet and the significant accumulation of the human population make the existence of green areas in cities more and more necessary. Even so, in developing countries, measuring the cultural benefits generated by these areas is scarce. The insertion of ecosystem services into urban planning is also very infrequent. This work sought to estimate the monetary value of the benefits generated by urban parks in different social contexts in the city of Recife. For this, we used the Contingent Valuation Method (CVM), applying 421 questionnaires in three parks located in neighborhoods with different characteristics. We adopted the Bivariate Probit to analyze the dichotomous questions and calculate the willingness to pay (WTP) estimates. The estimated flow of annual benefits in cultural ecosystem services is calculated based on two scenarios of potential beneficiaries who live between 800 m and 4,800 m from the parks. The results showed that the annual WTP varied between R$ 34 and R$ 87. The user characteristics such as age and sex were significant for the model, while the education level was not. Users with higher income had a higher WTP in absolute terms, while in proportional terms, users with lower income had a higher WTP. In this way, the results seem to demonstrate that the cultural ecosystem services provided by urban parks are more important in less favored social contexts. This factor can support more equitable planning in providing these public spaces.
Gravity waves signatures from anisotropic preinflation

We show that expanding or contracting Kasner universes are unstable due to the amplification of gravitational waves (GW). As an application of this general relativity effect, we consider a preinflationary anisotropic geometry characterized by a Kasner-like expansion, which is driven dynamically towards inflation by a scalar field. We investigate the evolution of linear metric fluctuations around this background, and calculate the amplification of the long-wavelength GW of a certain polarization during the anisotropic expansion (this effect is absent for another GW polarization, and for scalar fluctuations). These GW are superimposed to the usual tensor modes of quantum origin from inflation, and are potentially observable if the total number of inflationary $e$-folds exceeds the minimum required to homogenize the observable universe only by a small margin. Their contribution to the temperature anisotropy angular power spectrum decreases with the multipole $\ensuremath{\ell}$ as ${\ensuremath{\ell}}^{\ensuremath{-}p}$, where $p$ depends on the slope of the initial GW power spectrum. Constraints on the long-wavelength GW can be translated into limits on the total duration of inflation and the initial GW amplitude. The instability of classical GW (and zero-vacuum fluctuations of gravitons) during Kasner-like expansion (or contraction) may have other interesting applications. In particular, if GW become nonlinear, they can significantly alter the geometry before the onset of inflation.
Trapped Radiation Model Uncertainties: Model-Data and Model-Model Comparisons

The standard AP8 and AE8 models for predicting trapped proton and electron environments have been compared with several sets of flight data to evaluate model uncertainties. Model comparisons are made with flux and dose measurements made on various U.S. low-Earth orbit satellites (APEX, CRRES, DMSP. LDEF, NOAA) and Space Shuttle flights, on Russian satellites (Photon-8, Cosmos-1887, Cosmos-2044), and on the Russian Mir space station. This report gives the details of the model-data comparisons -- summary results in terms of empirical model uncertainty factors that can be applied for spacecraft design applications are given in a companion report. The results of model-model comparisons are also presented from standard AP8 and AE8 model predictions compared with the European Space Agency versions of AP8 and AE8 and with Russian trapped radiation models.
Science Impact on Country’s Socio-Economic Development

Studies that address the issues of statistical measurement, algorithms and methods of analysis and assessment of the science impact on country’s socio-economic development are still poorly developed. The degree of research in this area, taking into account the Kazakh specifics, is extremely low. Aim of this study is to research the assessment methods of science impact on the country’s social and economic development and conduct an appropriate assessment using the example of Kazakhstan. The conceptual framework of the methodology is the Impact Assessment Model that assesses the science impact on the development of the country through input (science development) and output (social and economic development) parameters. The information base includes the statistical data from the Bureau of National Statistics for the period from 2011 to 2020. The research results show that the assessment of the science impact can be performed at different levels, as well as different goals, objectives, technological trajectories and economic results that countries strive to achieve. There are index and econometric methods, microeconomic, case studies, patent and bibliometric studies and surveys to assess the science impact. Each has its own advantages and disadvantages. Today the potential of Kazakhstani science has not yet been revealed and the results of scientific research are used not enough in solving applied problems of the social and economic development of Kazakhstan. The scientific results obtained in the research course can be applied in the activities of Kazakhstani Ministries and can be used in the educational process.
Typical density profile for warm dark matter haloes

Using the model for (bottom-up) hierarchical halo growth recently developed by Salvador-Sole et al., we derive the typical spherically averaged density profile for haloes with several relevant masses in the concordant warm dark matter (ΛWDM) cosmology with non-thermal sterile neutrinos of two different masses. The predicted density profiles become flat at small radii, as expected from the effects of the spectrum cut-off. The core cannot be resolved, however, because the non-null particle velocity yields the fragmentation of minimum mass protohaloes in small nodes, which invalidates the model at the corresponding radii.
Large Eddy Simulation for Investigating Coupled Forest Canopy and Turbulence Influences on Atmospheric Chemistry

Exchanges of reactive gases between forests and the atmosphere influence tropospheric chemistry, climate, and ecosystems. Chemistry inside canopies can alter these exchanges yet understanding of the chemistry and processes influencing the chemistry is incomplete. Previous work prioritizes complex chemical mechanisms over micrometeorology in the multilayer models of forests used to understand in‐canopy chemistry and its impacts. Instead, here we use a new simplified chemical mechanism and resolve turbulence in a multilayer canopy model. Specifically, we describe a new version of the National Center for Atmospheric Research large eddy simulation (LES) coupled to both a multilayer canopy model and a chemical mechanism. The mechanism has 41 reactions and 19 gases for ozone, NOx (=NO + NO2), HOx (=OH + HO2), and isoprene chemistry. We evaluate the mechanism against two more complex mechanisms using box modeling. We configure the LES for a temperate deciduous forest and summer midday weak‐wind buoyancy‐forced conditions. The multilayer canopy model necessitates estimates of reactant sources and sinks at each canopy level, and thus we describe multilayer parameterizations for dry deposition and biogenic emissions. For the first time with an LES coupled to both a multilayer canopy and chemistry, we demonstrate variability in chemical reactions due to turbulence‐induced segregation of reactants inside and just above the canopy. For the cases examined here, in‐canopy segregation alters reaction rates that only consider well‐mixed conditions by up to −48% to +23%. For many reactions, segregation is stronger when soil NO emissions reflect the upper bound of observed values for temperate forests.
Radical substance-free phonology and feature learning

Abstract This article argues that phonological features have no substantive properties, instead, segments are assigned features by learning strategies set to the task of devising a computational system for a phonology that is consistent with the requirements of UG. I address two problems for such a substance-free model. The first is the Card-Grammar problem, which has been suggested to argue for universal substantive features, on the premise that, otherwise, language data cannot be stored in a fashion necessary to correct learning errors. The Card Grammar problem disappears, in a suitably modular theory of mind with learned interfaces, where the mind still can retain information not parsed in a particular grammar. The second problem is the need for a demonstration, not just an assertion, that a reasonable theory of grammar and learning which has no access to phonetic substance can yield a coherent system of feature assignments. This is accomplished by modeling the learning of features necessary for the phonology of Kerewe.
SYSTEMATIC STUDY OF GAMMA-RAY-BRIGHT BLAZARS WITH OPTICAL POLARIZATION AND GAMMA-RAY VARIABILITY

Blazars are highly variable active galactic nuclei that emit radiation at all wavelengths from radio to gamma rays. Polarized radiation from blazars is one key piece of evidence for synchrotron radiation at low energies, and it also varies dramatically. The polarization of blazars is of interest for understanding the origin, confinement, and propagation of jets. However, even though numerous measurements have been performed, the mechanisms behind jet creation, composition, and variability are still debated. We performed simultaneous gamma-ray and optical photopolarimetry observations of 45 blazars between 2008 July and 2014 December to investigate the mechanisms of variability and search for a basic relation between the several subclasses of blazars. We identify a correlation between the maximum degree of optical linear polarization and the gamma-ray luminosity or the ratio of gamma-ray to optical fluxes. Since the maximum polarization degree depends on the condition of the magnetic field (chaotic or ordered), this result implies a systematic difference in the intrinsic alignment of magnetic fields in parsec-scale relativistic jets between different types of blazars (flat-spectrum radio quasars vs. BL Lacs) and consequently between different types of radio galaxies (FR I versus FR II).
Disc-oscillation resonance and neutron star QPOs: 3:2 epicyclic orbital model

The high-frequency quasi-periodic oscillations (HF QPOs) that appear in the X-ray fluxes of low-mass X-ray binaries remain an unexplained phenomenon. Among other ideas, it has been suggested that a non-linear resonance between two oscillation modes in an accretion disc orbiting either a black hole or a neutron star plays a role in exciting the observed modulation. Several possible resonances have been discussed. A particular model assumes resonances in which the disc-oscillation modes have the eigenfrequencies equal to the radial and vertical epicyclic frequencies of geodesic orbital motion. This model has been discussed for black hole microquasar sources as well as for a group of neutron star sources. Assuming several neutron (strange) star equations of state and Hartle-Thorne geometry of rotating stars, we briefly compare the frequencies expected from the model to those observed. Our comparison implies that the inferred neutron star radius RNS is larger than the related radius of the marginally stable circular orbit rms for nuclear matter equations of state and spin frequencies up to 800 Hz. For the same range of spin and a strange star (MIT) equation of
Mass loss and expansion of ultra compact dwarf galaxies through gas expulsion and stellar evolution for top‐heavy stellar initial mass functions

The dynamical V-band mass-to-light ratios of ultra compact dwarf galaxies (UCDs) are higher than predicted by simple stellar population models with the canonical stellar initial mass function (IMF). One way to explain this finding is a top-heavy IMF so that the unseen mass is provided by additional remnants of high-mass stars. A possible explanation for why the IMF in UCDs could be top-heavy while this is not the case in less massive stellar systems is that encounters between protostars and stars become probable in forming massive systems. However, the required number of additional stellar remnants proves to be rather high, which raises the question of how their progenitors would affect the early evolution of a UCD. We have therefore calculated the first 200 Myr of the evolution of the UCDs, using the particle-mesh code SUPERBOX. It is assumed that the stellar populations of UCDs were created in an initial starburst, which implies heavy mass loss during the following ≈40 Myr due to primordial gas expulsion and supernova explosions. This mass loss is modelled by reducing the mass of the particles according to tabulated mass-loss histories which account for different IMFs, star formation efficiencies (SFEs), heating efficiencies (HEs), initial masses and initial extensions of the computed UCDs. For each combination of SFE and HE, we find objects that roughly resemble UCDs at the end of the simulation. For low SFEs, the IMF would have to be steeper than in the case of very high SFEs for the models not to expand too much. However, the main conclusion is that the existence of UCDs does not contradict the notion that their stellar populations formed rapidly and with a top-heavy IMF. We find tentative evidence that the UCDs may have had densities as high as 10 8 M ⊙ pc ―3 at birth. This will have to be confirmed by follow-up modelling.
Health-Related Quality of Life of Persons with Diabetic Foot Ulcers in a Cosmopolitan City in Northwestern Nigeria

Background: Diabetic foot ulcer is one of the most serious and disabling complications of diabetes mellitus (DM). It is a major source of morbidity, mortality, and a leading cause of hospitalization. It constitutes a major burden to the patient, family, and health-care system as well as impairs quality of life (QoL). The aim of this study was to determine the QoL of persons with diabetic foot ulcers attending two major hospitals in a cosmopolitan city in northwestern Nigeria. Materials and Methods: We conducted a descriptive cross-sectional study at the diabetes outpatient clinics and wards of two major hospitals in Kano, Northwestern Nigeria. Sociodemographic characteristics, type of DM, duration of DM, and the presence of risk factors for foot ulcers were assessed. The QoL of patients with and without foot ulcer was determined a well-validated questionnaire for chronic diseases, short form 36 (SF 36) health-related QoL questionnaire. Results: We recruited 394 patients with DM (163 males and 231 females) with mean age and duration of DM of 50.8 ± 12.5 years and 7.72 ± 6.65 years, respectively. Ninety-five percent of the study participants had type 2 DM. Foot ulcers were present in 57 (14.5%) study participants. The QoL was generally poor (P < 0.001) in patients with DFU, compared with those without DFU in all domains of the SF 36, that indicated poor QoL in the physical, mental, and emotional well-being of the patients. Conclusion: Diabetic foot ulcers are quite common and impart significantly on the QoL of persons with DM affecting their physical, mental, and emotional well-being. Early detection and management of foot ulcers will reduce the burden of the disease and improve the QoL of affected individuals.
WIDESPREAD PRESENCE OF SHALLOW CUSPS IN THE SURFACE-BRIGHTNESS PROFILE OF GLOBULAR CLUSTERS

Surface-brightness profiles of globular clusters with shallow central cusps (Σ ∼ Rν with −0.3 ≲ ν ≲ −0.05) have been associated by several recent studies with the presence of a central intermediate-mass black hole (IMBH). Such shallow slopes are observed in several globular clusters thanks to the high angular resolution of Hubble Space Telescope (HST) imaging. In this Letter, we evaluate whether shallow cusps are a unique signature of a central IMBH by analyzing a sample of direct N-body simulations of star clusters with and without a central IMBH. We “observe” the simulations as if they were HST images. Shallow cusps are common in our simulation sample: star clusters without an IMBH have ν ≳ −0.3 in the pre-core-collapse and core-collapse phases. Post-core-collapse clusters without an IMBH transition to steeper cusps, −0.7 ≲ ν ≲ −0.4, only if the primordial binary fraction is very small, fbin < 3%, and if there are few stellar-mass BHs remaining. Otherwise ν values overlap the range usually ascribed to the presence of an IMBH throughout the entire duration of the simulations. In addition, measuring ν is intrinsically prone to significant uncertainty, therefore typical measurement errors may lead to ν ⩾ −0.3 even when 〈ν〉 ≲ −0.4. Overall our analysis shows that a shallow cusp is not an unequivocal signature of a central IMBH and casts serious doubts on the usefulness of measuring ν in the context of the hunt for IMBHs in globular clusters.
Velocity Fields in the Solar Photosphere

Large-scale velocity fields in the solar photosphere remain a mystery in spite of many years of intensive studies. In this thesis, the new method of the measurements of the solar photospheric flow fields is proposed. It is based on local correlation tracking algorithm applied to full-disc dopplergrams obtained by Michelson Doppler Images (MDI) on-board the Solar and Heliospheric Observatory (SoHO). The method is tuned and tested on synthetic data, it is shown that the method is capable of measuring of horizontal velocity fields with an accuracy of 15 \mps. It is also shown that the method provides the measurements comparable with time-distance local helioseismology. The method is applied to real data sets. It reproduces well known properties of solar photospheric velocity fields. Moreover, the case studies show an evidence about the influence of the changes in the flow field topology on the stability of the eruptive filament and support the theory of the dynamical disconnection of bipolar sunspots from their magnetic roots. The method has a great perspective in the future use. The meridional flux transportation speed is also studied and it is shown that the direct measurement may differ from time-distance local helioseimology in the areas occupied by the strong magnetic field. This result has an impact to the flux transport dynamo models, which use the meridional speed as the essential observational input parameter.