Miracle-dz/UniFAR-FTUs huggingface dataset:
Lensing by Kerr black holes. I. General lens equation and magnification formula

We develop a unified, analytic framework for gravitational lensing by Kerr black holes. In this first paper, we present a new, general lens equation and magnification formula governing lensing by a compact object. Our lens equation assumes that the source and observer are in the asymptotically flat region and does not require a small angle approximation. Furthermore, it takes into account the displacement that occurs when the light ray's tangent lines at the source and observer do not meet on the lens plane. We then explore our lens equation in the case when the compact object is a Kerr black hole. Specifically, we give an explicit expression for the displacement when the observer is in the equatorial plane of the Kerr black hole as well as for the case of spherical symmetry.
Graph Neural Networks for Link Prediction with Subgraph Sketching

Many Graph Neural Networks (GNNs) perform poorly compared to simple heuristics on Link Prediction (LP) tasks. This is due to limitations in expressive power such as the inability to count triangles (the backbone of most LP heuristics) and because they can not distinguish automorphic nodes (those having identical structural roles). Both expressiveness issues can be alleviated by learning link (rather than node) representations and incorporating structural features such as triangle counts. Since explicit link representations are often prohibitively expensive, recent works resorted to subgraph-based methods, which have achieved state-of-the-art performance for LP, but suffer from poor efficiency due to high levels of redundancy between subgraphs. We analyze the components of subgraph GNN (SGNN) methods for link prediction. Based on our analysis, we propose a novel full-graph GNN called ELPH (Efficient Link Prediction with Hashing) that passes subgraph sketches as messages to approximate the key components of SGNNs without explicit subgraph construction. ELPH is provably more expressive than Message Passing GNNs (MPNNs). It outperforms existing SGNN models on many standard LP benchmarks while being orders of magnitude faster. However, it shares the common GNN limitation that it is only efficient when the dataset fits in GPU memory. Accordingly, we develop a highly scalable model, called BUDDY, which uses feature precomputation to circumvent this limitation without sacrificing predictive performance. Our experiments show that BUDDY also outperforms SGNNs on standard LP benchmarks while being highly scalable and faster than ELPH.
Application-Driven AI Paradigm for Human Action Recognition

Human action recognition in computer vision has been widely studied in recent years. However, most algorithms consider only certain action specially with even high computational cost. That is not suitable for practical applications with multiple actions to be identified with low computational cost. To meet various application scenarios, this paper presents a unified human action recognition framework composed of two modules, i.e., multi-form human detection and corresponding action classification. Among them, an open-source dataset is constructed to train a multi-form human detection model that distinguishes a human being's whole body, upper body or part body, and the followed action classification model is adopted to recognize such action as falling, sleeping or on-duty, etc. Some experimental results show that the unified framework is effective for various application scenarios. It is expected to be a new application-driven AI paradigm for human action recognition.
Exploring P versus NP

In this article, we discuss the question of whether P equals NP, we do not follow the line of research of many researchers, which is to try to find such a problem Q, and the problem Q belongs to the class of NP-complete, if the problem Q is proved to belong to P, then P and NP are the same, if the problem Q is proved not to belong to P, then P and NP are separated. Our research strategy in this article: Select a problem S of EXP-complete and reduce it to a problem of NP in polynomial time, then S belongs to NP, so EXP = NP, and then from the well-known P neq NP, derive P neq NP.
The AI Triplet: Computational, Conceptual, and Mathematical Knowledge in AI Education

Efforts to enhance education and broaden participation in AI will benefit from a systematic understanding of the competencies underlying AI expertise. In this paper, we observe that AI expertise requires integrating computational, conceptual, and mathematical knowledge and representations. We call this the ``AI triplet,'' similar in spirit to the ``chemistry triplet'' that has heavily influenced the past four decades of chemistry education research. We describe a theoretical foundation for this triplet and show how it maps onto two sample AI topics: tree search and gradient descent. Finally, just as the chemistry triplet has impacted chemistry education in concrete ways, we suggest two initial hypotheses for how the AI triplet might impact AI education: 1) how we can help AI students gain proficiency in moving between the corners of the triplet; and 2) how all corners of the AI triplet highlight the need for supporting students' spatial cognitive skills.
A Parameter-free and Projection-free Restarting Level Set Method for Adaptive Constrained Convex Optimization Under the Error Bound Condition

Recent efforts to accelerate first-order methods have focused on convex optimization problems that satisfy a geometric property known as error-bound condition, which covers a broad class of problems, including piece-wise linear programs and strongly convex programs. Parameter-free first-order methods that employ projection-free updates have the potential to broaden the benefit of acceleration. Such a method has been developed for unconstrained convex optimization but is lacking for general constrained convex optimization. We propose a parameter-free level-set method for the latter constrained case based on projection-free subgradient decent that exhibits accelerated convergence for problems that satisfy an error-bound condition. Our method maintains a separate copy of the level-set sub-problem for each level parameter value and restarts the computation of these copies based on objective function progress. Applying such a restarting scheme in a level-set context is novel and results in an algorithm that dynamically adapts the precision of each copy. This property is key to extending prior restarting methods based on static precision that have been proposed for unconstrained convex optimization to handle constraints. We report promising numerical performance relative to benchmark methods.
Arrays of optical vortices formed by 'fork' holograms

Singular light beams with optical vortices (OVs) are often generated by means of thin binary gratings with groove bifurcation ('fork' holograms), which produce a set of diffracted beams with different OV charges. Though a single separate beam is usually employed and studied, here we consider a whole set of diffracted OV beams which, under certain conditions, are involved in efficient mutual interference to form a characteristic pattern where the ring-like structure of separate OV beams is replaced by a series of bright and dark lines between the adjacent diffraction orders. This pattern, which is well developed for high diffraction orders, reflects the main spatial properties of the diffracted beams as well as those of a 'fork' grating used for their generation. In particular, this confirms a theoretical model for the diffracted beams, a so-called Kummer beam model, and enables one to determine the sign and the absolute value of the phase singularity embedded in the hologram.
CV1 in the globular cluster M 22: confirming its nature through X-ray observations and optical spectroscopy

Context. Observations of cataclysmic variables in globular cluster s appear to show a dearth of outbursts compared to those observed in the field. A number of explanations have been proposed, inclu ding low mass-transfer rates and/or moderate magnetic fields implying higher mass white dwarfs than the average observed in the fiel d. Alternatively this apparent dearth may be simply a selection bias. Aims. We examine multi-wavelength data of a new cataclysmic variable, CV1, in the globular cluster M 22 to try to constrain its period and magnetic nature, with an aim at understanding whether globular cluster cataclysmic variables are intrinsic ally different from those observed in the field. Methods. We use the sub-arcsecond resolution of the Chandra ACIS-S to identify the X-ray counterpart to CV1 and analyse the X-ray spectrum to determine the spectral model that best describes this source. We also examine the low resolution optical spectrum ◦ ′ ′′ ′′
Association Between Inflammatory Cytokines, Executive Function, and Substance Use in Patients With Opioid Use Disorder and Amphetamine-Type Stimulants Use Disorder

Abstract Background Long-term opioid and amphetamine-type stimulants (ATS) abuse may affect immunological function and impair executive function. We aimed to determine whether biomarkers of inflammation and executive function were associated with substance use in individuals with opioid use disorder (OUD) and ATS use disorder (ATSUD). The interactions between these biomarkers were also explored. Methods We assessed plasma cytokines [tumor necrosis factor (TNF)-α, C-reactive protein (CRP), interleukin (IL)-8, IL-6, transforming growth factor (TGF)-β1, brain-derived neurotrophic factor (BDNF), and executive function in terms of the Wisconsin Card Sorting Test (WCST) and Continuous Performance Test (CPT) in OUD and ATSUD patients and healthy controls (HC). OUD and ATSUD patients were followed for 12 weeks, and their urine morphine and amphetamine tests, cytokine levels, and executive function were repeatedly measured. Results We enrolled 483 patients and 145 HC. Plasma TNF-α, CRP, IL-8, IL-6, and BDNF levels and most subscale scores on the WCST and CPT significantly differed between OUD and ATSUD patients and HC. Increased TNF-α levels and more perseveration error on the WCST were significantly associated with more urine drug-positive results and less abstinence. Plasma IL-6 and CRP levels were significantly negatively correlated with WCST and CPT performance. Conclusion OUD and ATSUD patients had more inflammation and worse executive function than HC. Inflammatory markers and WCST performance were associated with their urinary drug results, and higher inflammation was associated with poor executive function. Studies on regulating the inflammatory process and enhancing executive function in OUD and ATSUD are warranted.
Boundary behavior of automorphic forms and transitivity for the modular group

Introduction This paper deals with a method of analyzing the boundary behavior (for nontangential approach) of the modulus of certain meromorphic automorphic forms on the modular group. The method is also applied to questions of transitivity for the modular group. The idea of the method may be simply stated: the line {zlz= + iy, y>0} (or a Stolz angle about it)may be decomposed into a series of intervals each one of which is "essentially". mapped into the standard fundamental region for the modular group by a specific transformation. Both the decomposition and the accompanying transforma-tions are given in terms ofthe continued fraction representation of Computa-tions involving boundary values and transitivity are thus made more tractable; in the first instance using the functional equation, and in the second, certain geometric and measure theoretic considerations.
The effect of heat stress on the epidermal growth factor (EGF)-mediated intracellular signaling, and changes cell behavior on swine testicular cell

Abstract At present, high environmental temperature is the main factor endangering animal production, growth and development. Therefore, the harmful effects of heat stress led by hot environment on livestock have attracted much attention. In this work, the cellar property and signaling property of epidermal growth factor (EGF) below heat stress remains unclear in swine testicular cells. Here, the effect of heat stress on EGF-induced intracellular signaling and cell behavior was explored in the ST (a porcine testis cell line). A series of experiments were done to study the cellular behavior and signaling properties of EGF under heat stress. It can be discovered which high ambient temperature changed the cellular characteristics of EGF/EGFR. The eventuates displayed when cells were exposed to thermal environment, EGF/EGFR basically did not internalize, mainly gathered on the cell membrane. Our group also researched the effect of EGF’s signaling properties, and the results showed that the ability of EGF to activate EGFR-mediated intracellular signaling decreased significantly under heat stress. Finally, this study illustrated that EGF’s cell behavior and signaling profile are obviously altered, indicating that heat stress seriously affected the biological activity of EGF/EGFR, which establish a solid foundation for studying the effect of the EGF on testicular tissue under heat environment.
WATER AND METHANOL MASER ACTIVITIES IN THE NGC 2024 FIR 6 REGION

The NGC 2024 FIR 6 region was observed in the water maser line at 22 GHz and the methanol class I maser lines at 44, 95, and 133 GHz. The water maser spectra displayed several velocity components and month-scale time variabilities. Most of the velocity components may be associated with FIR 6n, while one component was associated with FIR 4. A typical lifetime of the water maser velocity components is about eight months. The components showed velocity fluctuations with a typical drift rate of about 0.01 km s−1 day−1. The methanol class I masers were detected toward FIR 6. The methanol emission is confined within a narrow range around the systemic velocity of the FIR 6 cloud core. The methanol masers suggest the existence of shocks driven by either the expanding H ii region of FIR 6c or the outflow of FIR 6n.
Comparison of plasma and CSF biomarkers in predicting cognitive decline

Concentrations of amyloid‐β peptides (Aβ42/Aβ40) and neurofilament light (NfL) can be measured in plasma or cerebrospinal fluid (CSF) and are associated with Alzheimer’s disease brain pathology and cognitive impairment. This study directly compared plasma and CSF measures of Aβ42/Aβ40 and NfL as predictors of cognitive decline.
Geospatial insights into the controls of microbialite formation at Laguna Negra, Argentina

Microbialites provide a record of the interaction of microorganisms with their environment constituting a record of microbial life and environments through geologic time. Our capacity to interpret this record is limited by an incomplete understanding of the microbial, geochemical, and physical processes that influence microbialite formation and morphogenesis. The modern system Laguna Negra in Catamarca Province, Argentina contains microbialites in a zone of carbonate precipitation associated with physico‐chemical gradients and variable microbial community structure, making it an ideal location to study how these processes interact to drive microbialite formation. In this study, we investigated the geospatial relationships between carbonate morphology, geochemistry, and microbial community at the macro‐ (decimeter) to mega‐ (meter) scale by combining high‐resolution imagery with field observations. We mapped the distribution of carbonate morphologies and allochtonously‐derived volcaniclasts and correlated these with sedimentary matrices and geochemical parameters. Our work shows that the macroscale distribution of different carbonate morphologies spatially correlates with microbial mat distributions—a result consistent with previous microscale observations. Specifically, microbialitic carbonate morphologies more commonly occur associated with microbial mats while abiotically derived carbonate morphologies were less commonly associated with microbial mats. Spatial variability in the size and abundance of mineralized structures was also observed, however, the processes controlling this variability remains unclear and likely represent a combination of microbial, geochemical, and physical processes. Likewise, the processes controlling the spatial distribution of microbial mats at Laguna Negra are also unresolved. Our results suggest that in addition to the physical drivers observed in other modern environments, variability in the spatial distribution of microbialites and other carbonate morphologies at the macro‐ to megascale can be controlled by microbial processes. Overall, this study provides insight into the interpretation of microbialite occurrence and distributions in the geologic record and highlights the utility of geospatial statistics to probe the controls of microbialite formation in other environments.
RADIAL ANGULAR MOMENTUM TRANSFER AND MAGNETIC BARRIER FOR SHORT-TYPE GAMMA-RAY-BURST CENTRAL ENGINE ACTIVITY

Soft extended emission (EE) following initial hard spikes up to 100 s was observed with Swift/BAT for about half of known short-type gamma-ray bursts (SGRBs). This challenges the conversional central engine models of SGRBs, i.e., compact star merger models. In the framework of black-hole–neutron-star merger models, we study the roles of radial angular momentum transfer in the disk and the magnetic barrier around the black hole in the activity of SGRB central engines. We show that radial angular momentum transfer may significantly prolong the lifetime of the accretion process, which may be divided into multiple episodes by the magnetic barrier. Our numerical calculations based on models of neutrino-dominated accretion flows suggest that disk mass is critical for producing the observed EE. In the case of the mass being ∼0.8 M☉, our model can reproduce the observed timescale and luminosity of both the main and the EE episodes in a reasonable parameter set. The predicted luminosity of the EE component is lower than the observed EE within about one order of magnitude and the timescale is shorter than 20 s if the disk mass is ∼0.2 M☉. Swift/BAT-like instruments may be not sensitive enough to detect the EE component in this case. We argue that the EE component could be a probe for the merger process and disk formation for compact star mergers.
AMI Large Array radio continuum observations of Spitzer c2d small clouds and cores

We perform deep 1.8 cm radio continuum imaging towards thirteen protostellar regions selected from the Spitzer c2d small clouds and cores programme at high resolution (25 00 ) in order to detect and quantify the cm‐wave emission from deeply embedded young protostars. Within these regions we detect fifteen compact radio sources which we identify as radio protostars including two probable new detections. The sample is in general of low bolometric luminosity and contains several of the newly detected VeLLO sources. We determine the 1.8 cm radio luminosity to bolometric luminosity correlation, Lrad − Lbol, for the sample and discuss the nature of the radio emission in terms of the available sources of ionized gas. We also investigate the Lrad− LIR correlation and suggest that radio flux density may be used as a proxy for the internal luminosity of low luminosity protostars.
Population Gradients in the SDSS Galaxy Catalog. The role of merging

We investigate the role of the environment on the colour and stellar population gradients in a local sample of ~3500 central and ~1150 satellite SDSS early-type galaxies (ETGs). The environment is parameterized in terms of the number of satellite galaxies, N_gal in each group. For central galaxies, we find that both optical colour and mass-to-light (M/L) ratio gradients are shallower in central galaxies residing in denser environments (higher N_gal). This trend is driven by metallicity gradients, while age gradients appear to be less dependent on the environment and to have a larger scatter. On the other hand, satellites do not show any differences in terms of the environment. The same results are found if galaxies are classified by central age, and both central and satellite galaxies have shallower gradients if they are older and steeper gradients if younger, satellites being independent of ages. In central galaxies, we show that the observed trends can be explained with the occurrence of dry mergings, which are more numerous in denser environments and producing shallower colour gradients because of more uniform metallicity distributions due to the mixing of stellar populations, while no final clues about merging occurrence can be obtained for satellites. Finally we discuss all systematics on stellar population fitting and their impact on the final results.
Changes in Hungarian academic psychology after the end of “people's democracy”

Abstract The paper surveys the last 30 years of Hungarian academic psychology. Around 1989–1990, the time of the great social changes Hungarian psychology was rather Westernized, but still a relatively small scientific field and applied profession. The opening and liberalization of politics made psychology in Hungary a booming profession and a rich research field. Education of psychologists was spreading, and becoming more Westernized in textbook usage and reading materials. Entrance numbers at two universities with 80 students were replaced by 2010 by 6 university programs and about 8000 incoming students. The training system is a Bologna type BA + MA + PhD system, The educational booming has its own problems. As all university subjects, psychology training is also underfinanced, with high teaching loads and a move by university management towards applied areas, neglecting basic research. The research activity is characterized by a fivefold increase of English language publications coming from Hungary over a 20 years period. University research was strengthened, and competitive grant systems were introduced, whth good success aretes by psychologists. Here again, managerial thinking questions many aspects of basic research and liberalized science management. These factors are peculiar to psychology, but they do have an impact on it. The paper gives some details about one chapter of academic psychology, cognitive psychology. Institutionally, support by the Soros foundation in the 90s for the university cognitive programs had as one consequence that three departments of cognition are active in Budapest today. Another aspect of insitutional development was the series of multidisciplinary conferences in Hungary (MAKOG), and Hungarian involvement in international graduate training programs in cognitive science. The most successful cognitive group, at Central European University (5 ERC grants, publications in leading journals) is recently chased out of Hungary by anti‐Western and antiliberal legal moves. This would certainly have a detrimental effect on Hungarian cognitive psychology for quite a time.