Miracle-dz/UniFAR-FTUs huggingface dataset:
MINING THE SLOAN DIGITAL SKY SURVEY IN SEARCH OF EXTREMELY α-POOR STARS IN THE GALAXY

As we know, the majority of metal-poor Galactic halo stars appear to have chemical abundances that were enhanced by α-elements (e.g., O, Mg, Si, Ca, and Ti) during the early stage of the Galaxy. Observed metal-poor halo stars preserved this pattern by exhibiting abundance ratios [α/Fe] ∼+0.4. A few striking exceptions that show severe departures from the general enhanced α-element chemical abundance trends of the halo have been discovered in recent years. They possess relatively low [α/Fe] compared to other comparable-metallicity stars, with abundance ratios over 0.5 dex lower. These stars may have a different chemical enrichment history from the majority of the halo. Similarly, low-α abundances are also displayed by satellite dwarf spheroidal (dSph) galaxies. We present a method to select extremely α-poor (EAP) stars from the SDSS/SEGUE survey. The method consists of a two-step approach. In the first step, we select suspected metal-poor ([Fe/H] <−0.5) and α-poor ([Mg/Fe] <0) stars as our targets. In the second step, we determine [Mg/Fe] from low-resolution (R = 2000) stellar spectra for our targets and select stars with [Mg/Fe] <−0.1 as candidate EAP stars. In a sample of 40,000 stars with atmospheric parameters in the range of Teff = [4500, 7000] K, log g = [1.0, 5.0], and [Fe/H] = [−4.0, +0.5], 14 candidate stars were identified. Three of these stars are found to have already been confirmed by other research.
Far-field pattern determination from the near-field amplitude on two surfaces

The possibility of determining the far field of radiating systems by measuring only the near-field amplitude is investigated. The main difficulties of the problem are examined in some detail and a new near-field/far-field transformation technique is developed, based on the measurement of the near-field amplitude over two surfaces surrounding the antenna under test. The accuracy of the far-field reconstruction results are related both to the distance between such surfaces and to some a priori information concerning the near-field phase and/or the radiating system. The information on the radiating system allows relaxation of the need for any information on the near-field phase provided that the distance between the measurement surfaces is high enough. Conversely, the knowledge of a more or less corrupted near-field phase allows reduction of such distances without affecting the accuracy of the far-field reconstruction. Numerical examples validating the effectiveness of the developed algorithm are provided for the planar scanning case. >
Gauss–Newton and full Newton methods in frequency–space seismic waveform inversion

SUMMARY By specifying a discrete matrix formulation for the frequency^space modelling problem for linear partial diierential equations (‘FDM’ methods), it is possible to derive a matrix formalism for standard iterative non-linear inverse methods, such as the gradient (steepest descent) method, the Gauss^Newton method and the full Newton method. We obtain expressions for each of these methods directly from the discrete FDM method, and we refer to this approach as frequency-domain inversion (FDI). The FDI methods are based on simple notions of matrix algebra, but are nevertheless very general. The FDI methods only require that the original partial diierential equations can be expressed as a discrete boundary-value problem (that is as a matrix problem). Simple algebraic manipulation of the FDI expressions allows us to compute the gradient of the mis¢t function using only three forward modelling steps (one to compute the residuals, one to backpropagate the residuals, and a ¢nal computation to compute a step length). This result is exactly analogous to earlier backpropagation methods derived using methods of functional analysis for continuous problems. Following from the simplicity of this result, we give FDI expressions for the approximate Hessian matrix used in the Gauss^Newton method, and the full Hessian matrix used in the full Newton method. In a new development, we show that the additional term in the exact Hessian, ignored in the Gauss^Newton method, can be e⁄ciently computed using a backpropagation approach similar to that used to compute the gradient vector. The additional term in the Hessian predicts the degradation of linearized inversions due to the presence of ¢rst-order multiples (such as free-surface multiples in seismic data). Another interpretation is that this term predicts changes in the gradient vector due to second-order non-linear eiects. In a numerical test, the Gauss^Newton and full Newton methods prove eiective in helping to solve the di⁄cult non-linear problem of extracting a smooth background velocity model from surface seismic-re£ection data.
Imaging performance of multi-etalon bidimensional spectrometers

Aims. In recent years, several new solar and nighttime panoramic spectrometers based on Fabry-Perot interferometers have been successfully developed. In this paper we evaluate the imaging performance of the two types of mountings that have been adopted, telecentric and classic, in particular trying to understand which one might be more suitable for future large-aperture solar telescopes. Methods. Numerical code was written to simulate the behavior of such spectrometers, on the basis of the theory of Fourier optics. This code was used to simulate different instrument configurations and was tested on previous results obtained either analytically or numerically by other authors. Results. Calculations of the system MTF and Strehl ratios show that both mountings may perform very close to theoretical expectations. However, gap irregularities in the interferometers may alter the optical quality of the monochromatic images. In the case of the classical mounting in a collimated beam, it is possible to partially compensate for the resulting errors in the wavefront emerging from the interferometers with a suitable phase plate. We also performed an observational test of the optical quality delivered by the IBIS interferometer installed at the Dunn Solar Telescope of the National Solar Observatory, with the results substantially confirming the calculations. Conclusions. It follows from our results that both mountings may be efficiently used for solar bidimensional spectroscopy. The final choice depends on the tradeoff between factors such as image quality, field of view, and acceptable wavelength shift.
Agnotology: learning from mistakes

Abstract. Replication is an important part of science, and by repeating past analyses, we show that a number of papers in the scientific literature contain severe methodological flaws which can easily be identified through simple tests and demonstrations. In many cases, shortcomings are related to a lack of robustness, leading to results that are not universally valid but rather an artifact of a particular experimental set-up. Some examples presented here have ignored data that do not fit the conclusions, and in several other cases, inappropriate statistical methods have been adopted or conclusions have been based on misconceived physics. These papers may serve as educational case studies for why certain analytical approaches sometimes are unsuitable in providing reliable answers. They also highlight the merit of replication. A lack of common replication has repercussions for the quality of the scientific literature, and may be a reason why some controversial questions remain unanswered even when ignorance could be reduced. Agnotology is the study of such ignorance. A free and open-source software is provided for demonstration purposes.
Pharmacological Activities of Mogrol: Potential Phytochemical against Different Diseases

Recently, mogrol has emerged as an important therapeutic candidate with multiple potential pharmacological properties, including neuroprotective, anticancer, anti-inflammatory, antiobesity, antidiabetes, and exerting a protective effect on different organs such as the lungs, bone, brain, and colon. Pharmacokinetic studies also highlighted the potential of mogrol as a therapeutic. Studies were also conducted to design and synthesize the analogs of mogrol to achieve better activities against different diseases. The literature also highlighted the possible molecular mechanism behind pharmacological activities, which suggested the role of several important targets, including AMPK, TNF-α, and NF-κB. These important mogrol targets were verified in different studies, indicating the possible role of mogrol in other associated diseases. Still, the compilation of pharmacological properties, possible molecular mechanisms, and important targets of the mogrol is missing in the literature. The current study not only provides the compilation of information regarding pharmacological activities but also highlights the current gaps and suggests the precise direction for the development of mogrol as a therapeutic against different diseases.
Infrared spectropolarimetry of the Galactic Centre: magnetic alignment in the discrete sources

On presente les resultats d'observations spectropolarimetriques 8−13 μm des sources du centre galactique. Toutes les sources presentent une polarisation interstellaire due a l'absoption par des grains de silicate alignes et ces grains semblent etre spatialement separes sur la ligne de visee de ceux qui provoquent la polarisation aux plus courtes longueurs d'onde. On discute de l'origine de l'alignement des grains
Low-luminosity AGNs

Context. We propose that low-luminosity AGNs (LLAGNs), or some of them, are sources extracting their energy from the black hole rotation by the Blandford-Znajek mechanism. Aims. It is shown that almost all energy of the black hole rotation is converted to relativistic protons in a jet. Owing to the high magnetic-field magnitude near the black hole, required for the Blandford-Znajek mechanism, electrons are not strongly accelerated because of their high synchrotron losses. Conversely, protons gain energies on the order of (10 4 −10 5 )mpc 2 when crossing the light cylinder surface. Protons are also accelerated in a disk by 2D turbulent motion of the disk matter. Methods. We calculate the luminosity of the synchrotron radiation by fast protons in the disk, the frequencies of this radiation being in the infrared band, and the luminosities corresponding to LLAGNs. We measure the very high energy (VHE) radiation luminosities from the disk and the jet, finding that VHE radiation is produced by collisions of accelerated protons with surrounding matter. Results. We predict a correlation between the infrared luminosity LIR and the VHE luminosity LVHE of the disk, LVHE ∝ L 1/2 IR M 3/2 , where M is the mass of a black hole. Two low-luminosity sources Sgr A* and M 87, for which luminosities LIR and LVHE are known, appear to follow this scheme. Conclusions. The discovery of new bright VHE sources from LLAGNs could confirm our hypotheses that they are energy sources powered by the Blandford-Znajek mechanism.
High-order velocity structure functions in turbulent shear flows

Measurements are presented of the velocity structure function on the axis of a turbulent jet at Reynolds numbers Rλ ≤ 852 and in a turbulent duct flow at Rλ = 515. Moments of the structure function up to the eighteenth order were calculated, primarily with a view to establish accurately the dependence on the order of the inertial range power-law exponent and to draw conclusions about the distribution of energy transfer in the inertial range. Adequate definition of the probability density of the structure function was achieved only for moments of order n ≤ 10. It is shown, however, that, although the values of moments of n > 10 diverges from their true values, the dependence of the moment of the structure function on the separation r is still given to a fair accuracy for moments up to n ≈ 18. The results demonstrate that the inertial-range power-law exponent is closely approximated by a quadratic dependence on the power which for lower-order moments (n [lsim ] 12) would be consistent with a lognormal distribution. Higher-order moments diverge, however, from a lognormal distribution, which gives weight to Mandelbrot's (1971) conjecture that ‘Kolmogorov's third hypothesis’ is untenable in the strict sense. The intermittency parameter μ, appearing in the power-law exponent, has been determined from sixth-order moments 〈(δμ)6〉 ∼ r2−μ to be μ = 0.2 ± 0.05. This value coincides with that determined from non-centred dissipation correlations measured in identical conditions.
Automatic Ionospheric Weather Monitoring With DPS‐4D Ionosonde and ARTIST‐5 Autoscaler: System Performance at a Mid‐Latitude Observatory

The performance of the digital ionospheric sounder at the mid‐latitude site of Dourbes, Belgium (4.6°E, 50.1°N) is evaluated and detailed here in terms of its capability to deliver ionograms of good quality at different sounding rates together with the quality of the automated scaling of ionospheric characteristics done by the dedicated computer software. The instrument is a Lowell Digisonde‐4D, also known as the Digital Portable Sounder 4D (DPS‐4D), equipped with the latest version 5 of the autoscaling software, Automatic Real‐Time Ionogram Scaler with True height. A thorough statistical analysis has been carried out of the automatic processing and scaling of the key ionospheric characteristics: critical frequencies, virtual heights, maximum usable frequency, and propagation factor. This analysis is based on the manually scaled hourly values of the above‐mentioned characteristics for the time period since the installation of the DPS‐4D in April 2011. Based on the analysis, the error bounds (with 95% probability) have been determined for each characteristic. Results are expected to be of particular interest to researchers, developers and users of the great variety of ionosphere/space weather monitoring services worldwide.
A nomogram for predicting risk of death during hospitalization in elderly patients with Alzheimer's disease at the time of admission

Background and objectives Elderly patients with Alzheimer's disease (AD) often have multiple underlying disorders that lead to frequent hospital admissions and are associated with adverse outcomes such as in-hospital mortality. The aim of our study was to develop a nomogram to be used at hospital admission for predicting the risk of death in patients with AD during hospitalization. Methods We established a prediction model based on a dataset of 328 patients hospitalized with AD -who were admitted and discharged from January 2015 to December 2020. A multivariate logistic regression analysis method combined with a minimum absolute contraction and selection operator regression model was used to establish the prediction model. The identification, calibration, and clinical usefulness of the predictive model were evaluated using the C-index, calibration diagram, and decision curve analysis. Internal validation was evaluated using bootstrapping. Results The independent risk factors included in our nomogram were diabetes, coronary heart disease (CHD), heart failure, hypotension, chronic obstructive pulmonary disease (COPD), cerebral infarction, chronic kidney disease (CKD), anemia, activities of daily living (ADL) and systolic blood pressure (SBP). The C-index and AUC of the model were both 0.954 (95% CI: 0.929–0.978), suggesting that the model had accurate discrimination ability and calibration. Internal validation achieved a good C-index of 0.940. Conclusion The nomogram including the comorbidities (i.e., diabetes, CHD, heart failure, hypotension, COPD, cerebral infarction, anemia and CKD), ADL and SBP can be conveniently used to facilitate individualized identification of risk of death during hospitalization in patients with AD.
Singularity Structure of Third‐Order Dynamical Systems. I

A general third‐order dynamical system with polynomial right‐hand sides of finite degrees in the dependent variables is analyzed to unravel the singularity structure of its solutions about a movable singular point. To that end, the system is first transformed to a second‐order Briot–Bouquet system and a third auxiliary equation via a transformation, similar to one used earlier by R. A. Smith in 1973–1974 for a general second‐order dynamical system. This transformation imposes some constraints on the coefficients appearing in the general third‐order system. The known results for the second‐order Briot–Bouquet system are used to explicitly write out Laurent or psi‐series solutions of the general third‐order system about a movable singularity. The convergence of the relevant series solutions in a deleted neighborhood of the singularity is ensured. The theory developed here is illustrated with the help of the May–Leonard system.
Large Eddy Simulation of Dust Devils in a Diurnally-Evolving Convective Mixed Layer

Formation of dust devils in diurnally-evolving convective mixed layers is studied by means of a large eddy simulation. It is found that a weaker general wind and a stronger surface heat flux for which cellular convection rather than roll convection prevails are favorable for the formation of dust devils. The simulation results show that when the general wind is weak, the maximum vertical vorticity in the convective mixed layer is a monotonically increasing function of w * , where w * is the convective velocity scale for a convective mixed layer. Therefore, dust devils occur most frequently in the early afternoon when the heat flux is large and the convective mixed layer grows to a significant height. The simulated dust devils are found to have a horizontal length scale comparable with observed larger dust devils. They have either one-celled or two-celled structure. Some of them have a one-celled structure initially, but later evolve into a two-celled structure.
To What Extent are Japanese University Students Successful in Motivating Themselves to Learn English through Project-based Language Education? An Assessment of Students after Two Years of PBL-based English Language Education

The objective of this study is to evaluate the efficacy of project-based learning (PBL) methods in teaching English at the Japanese university level from the perspective of motivational research. The case study focuses on the Project-based English Program (PEP) at a large private university in Japan, examining whether the program not only enhances English proficiency, but also motivates students to a higher level of self-determination. By analyzing these outcomes, this paper discusses the added value of PBL-based English education in terms of its effectiveness in motivating students. The analysis reveals that PEP has improved the English proficiency of the participants over the two-year curriculum, and that in terms of motivation, PEP has been successful to some extent in cultivating identified regulation, a relatively high level of self-determination among extrinsic motivation for English language learning. The results also indicate that the group tended to develop intrinsic motivation, a motivation with an even higher level of self-determination, suggesting that PBL-style classes are effective in facilitating the acquisition of high self-determined motivation. However, the results for stimulation, one aspect of intrinsic motivation, tended to show almost no acquisition, and the results for introjected regulation, an extrinsic motivation, were also scattered, suggesting that learners may retain some hesitation, conflict, and stress according to motivation theory. These findings can be utilized to improve educational programs in the future.
Log-Linear Randomized-Response Models Taking Self-Protective Response Behavior Into Account

Randomized response (RR) is an interview technique designed to eliminate response bias when sensitive questions are asked. In RR the answer depends partly on the true status of the respondent and partly on the outcome of a randomizing device. Although RR elicits more honest answers than direct questions do, it is susceptible to self-protective response behavior; that is, the respondent gives an evasive answer irrespective of the outcome of the randomizing device. The authors present a log-linear RR model that accounts for this kind of self-protection (SP). The main results of this SP model are estimates of (1) the probability of SP, (2) the log-linear parameters describing the associations between the sensitive characteristics, and (3) the prevalence of the sensitive characteristics that are corrected for SP. The model is illustrated with two examples from a Dutch survey measuring noncompliance with social welfare rules.
A Data-Driven Control-Policy-Based Driving Safety Analysis System for Autonomous Vehicles

An autonomous vehicle (AV) is a combination of subsystems, measuring its driving environments with different sensors (e.g., camera, RADAR, and LiDAR) in real time. AVs follow their control policies and make real-time control decisions based on sensor measurements to ensure driving safety. Control policies in an AV are usually implemented with codes and not open to the public and drivers, which results in people’s strong concerns about driving safety. In this article, we propose a data-driven control policy-based driving safety analysis system (PoSa) to analyze the driving safety of a target AV. In PoSa, we first build a data-driven control policy extraction method to extract control policies of a target AV based on its historical driving data. Then, we develop a hazard driving scenario identification method to identify possible hazard driving scenarios of a target AV by executing the extracted control policies under different driving scenarios. Finally, we use vehicle driving data from one industry-standard AV platform (Baidu Apollo) to evaluate PoSa’s hazard driving scenario identification performance. We compared its identification results with Baidu AV accident reports from California DMV and the hazard driving scenario identification results cover as many as 89% hazard driving scenarios in the Baidu AV accident report, which demonstrates that PoSa has good performance on identifying hazard driving scenarios and its identification results can be used to optimize control policies for driving safety improvement.
Metabolome-Based Classification of Snake Venoms by Bioinformatic Tools

Snakebite is considered a neglected tropical disease, and it is one of the most intricate ones. The variability found in snake venom is what makes it immensely complex to study. These variations are present both in the big and the small molecules found in snake venom. This study focused on examining the variability found in the venom’s small molecules (i.e., mass range of 100–1000 Da) between two main families of venomous snakes—Elapidae and Viperidae—managing to create a model able to classify unknown samples by means of specific features, which can be extracted from their LC–MS data and output in a comprehensive list. The developed model also allowed further insight into the composition of snake venom by highlighting the most relevant metabolites of each group by clustering similarly composed venoms. The model was created by means of support vector machines and used 20 features, which were merged into 10 principal components. All samples from the first and second validation data subsets were correctly classified. Biological hypotheses relevant to the variation regarding the metabolites that were identified are also given.