Miracle-dz/UniFAR-FTUs huggingface dataset:
Generalized adaptive smoothing for multiscale edge detection

Discontinuity preserving smoothing for edge detection is receiving more attention because of the fact that it does not suffer the disadvantage of linear filtering which smooth edges as well as noise. Adaptive smoothing is basically a discontinuity preserving smoothing scheme which preserves edges with gradient magnitude greater the preset threshold value. However, it suffers a leaking effect in its long term iterative behavior. The propagation of smoothing in the low contrast area will sometimes affect the preservation of high contrast edges. This paper proposes a remedy for adaptive smoothing which includes the original image in the iteration process. It provides not only a more stable iterative behavior, but also introduces a new scaling parameter which facilitates multiple scale processing. The study of iterative behavior of the proposed generalized adaptive smoothing as well as automatic selection of the number of iterations is presented.
Characterization of bolting behaviour in garlic (Allium sativum) using SNP

The present research was conducted to evaluate the bolting (incomplete bolters and non-bolters) behaviour in garlic (Allium sativum L.) accessions collected from different geographical areas. A total of 96 genotypes collected from different sources were used for genotype sequencing to identify SNP but only 73 genotypes among them showed good amplification. A primer (AsLFY) was designed by using reference of already designed gene specific primer (gALFY-2) by Rotem et al. (2007). After amplification, sequencing of these 73 genotypes was done; SNP (CCGTCG) was at 301 bp from initiation codon, i.e. G for non-bolters genotypes and A for incomplete bolter genotypes. Thus, the identified SNP would help in detecting incomplete bolter and non-bolter genotypes at seedling stage which can be useful for garlic breeding programmes.
Association between Genetically Proxied Inhibition of HMG-CoA Reductase and Age at Onset of Huntington’s Disease

Background: Previous studies have found that statins may play a potential role in the age at onset (AAO) of Huntington’s disease (HD). We performed this Mendelian randomization (MR) study to assess the association between genetically proxied inhibition of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and low-density lipoprotein (LDL) cholesterol with age at onset of HD. Methods: Single-nucleotide polymorphisms (SNPs) in HMG-CoA reductase associated with LDL cholesterol in a genome-wide association study (GWAS) analysis were used. The summary data of residual AAO of HD were obtained from a GWAS meta-analysis (n = 9064 HD patients). MR estimates representing lifelong inhibition of drug targets were generated using random-effects inverse-variance weighted analysis. Results: Genetically proxied plasma LDL cholesterol (β = 0.039, 95% CI = −0.454 to 0.531) and HMG-CoA reductase inhibition equivalent to a 1 mmol/L (38.7 mg/dL) reduction in LDL cholesterol (β = −2.228, 95% CI = −4.830 to 0.374) were not associated with age at onset of HD. Conclusion: The plasma LDL cholesterol levels and the reduction of plasma LDL cholesterol levels by the inhibition of HMG-CoA reductase (i.e., statins) were not associated with the age of HD onset.
High-Resolution Near-Infrared Imaging and Polarimetry of Four Proto-Planetary Nebulae

High-resolution near-infrared Hubble Space Telescope (HST) NICMOS (F160W, F222M) images and polarization (2 μm) observations were made of four bipolar proto–planetary nebulae (PPNs): IRAS 17150-3224, 17441-2411, 17245-3951, and 16594-4656. The first three of these are viewed nearly edge-on, and for the first time the central stars in them are seen. Color maps reveal a reddened torus between the bipolr lobes in the edge-on cases, with bluer lobes. The polarization values are high, with maximum values ranging from 40% to 80%. The polarization patterns are basically centrosymmetric, with some deviations in the low-polarization equatorial regions. For IRAS 17150-3224, circumstellar arcs are seen at 1.6 μm, along with a newly discovered loop in the equatorial region. Bright caps are seen at the end of the lobes, indicating that they are not open-ended. A distinct point-symmetric pattern is seen in the strengths of the polarization vectors, especially in IRAS 17150-3224. HST NICMOS observations provide a valuable complement to the WFPC2 visible images in deriving the basic structure of bipolar PPNs.
Primordial black holes under the double inflationary power spectrum

Recently, it has been shown that the primordial black holes (PBHs) produced by near critical collapse in the expanding universe have a scaling mass relation similar to that of black holes produced in asymptotically flat spacetime. Distinct from PBHs formed with mass about the horizon mass (Type I), the PBHs with the scaling relation (Type II) can be created with a range of masses at a given formation time. In general, only the case in which the PBH formation is concentrated at one epoch has been considered. However, it is expected that PBH formation is possible over a broad range of epochs if the density fluctuation has a rather large amplitude and smooth scale dependence. In this paper, we study the PBH formation for both types assuming the power spectrum of double inflationary models in which the small scale fluctuations could have large amplitudes independent of the CMBR anisotropy. The mass spectrum of Type II PBHs is newly constructed without limiting the PBH formation period. The double inflationary power spectrum is assumed to be of double simple power-law which are smoothly connected. Under the assumed power spectrum, the accumulation of small PBHs formed at later times is important and the mass range is significantly broadened for both Types. The PBH mass spectra are far smoother than the observed MACHO spectrum due to our assumption of a smooth spectrum. In order to fit the observation, a more spiky spectrum is required.
Magnetic field strengths in the hotspots of 3C 33 and 111

We report on ROSAT HRI observations of the nearby powerful radio galaxies 3C33 and 3C111, which both have detected optical hot spots. We find nuclear X-ray sources in both objects, but no X-ray emission from the hot spots. This confirms the presence of a high-energy cutoff in the spectrum of synchrotron-emitting electrons. Since these electrons necessarily scatter the synchrotron photons by the inverse-Compton process, our upper limits on the X-ray fluxes of the hot spots allow us to set lower limits of a few nanotesla on their magnetic flux density, close to or greater than the fields implied by equipartition of energy between radiating particles and magnetic field.
Optical, Near-IR, and X-Ray Observations of SN 2015J and Its Host Galaxy

SN 2015J was discovered on 2015 April 27th and is classified as an SN IIn. At first, it appeared to be an orphan SN candidate, i.e., without any clear identification of its host galaxy. Here, we present an analysis of the observations carried out by the VLT 8 m class telescope with the FORS2 camera in the R band and the Magellan telescope (6.5 m) equipped with the IMACS Short-Camera (V and I filters) and the FourStar camera (Ks filter). We show that SN 2015J resides in what appears to be a very compact galaxy, establishing a relation between the SN event and its natural host. We also present and discuss archival and new X-ray data centered on SN 2015J. At the time of the supernova explosion, Swift/XRT observations were made and a weak X-ray source was detected at the location of SN 2015J. Almost one year later, the same source was unambiguously identified during serendipitous observations by Swift/XRT and XMM-Newton, clearly showing an enhancement of the 0.3–10 keV band flux by a factor with respect to the initial state. Swift/XRT observations show that the source is still active in the X-rays at a level of counts s−1. The unabsorbed X-ray luminosity derived from the XMM-Newton slew and SWIFT observations, erg s−1, places SN 2015J among the brightest young supernovae in X-rays.
Activity Analyses for Solar-type Stars Observed with Kepler. II. Magnetic Feature versus Flare Activity

The light curves of solar-type stars present both periodic fluctuation and flare spikes. The gradual periodic fluctuation is interpreted as the rotational modulation of magnetic features on the stellar surface and is used to deduce magnetic feature activity properties. The flare spikes in light curves are used to derive flare activity properties. In this paper, we analyze the light curve data of three solar-type stars (KIC 6034120, KIC 3118883, and KIC 10528093) observed with Kepler space telescope and investigate the relationship between their magnetic feature activities and flare activities. The analysis shows that: (1) both the magnetic feature activity and the flare activity exhibit long-term variations as the Sun does; (2) unlike the Sun, the long-term variations of magnetic feature activity and flare activity are not in phase with each other; (3) the analysis of star KIC 6034120 suggests that the long-term variations of magnetic feature activity and flare activity have a similar cycle length. Our analysis and results indicate that the magnetic features that dominate rotational modulation and the flares possibly have different source regions, although they may be influenced by the magnetic field generated through a same dynamo process.
Triplet superconductivity in quasi-one-dimensional systems

We study a Hubbard Hamiltonian, including a quite general nearest-neighbor interaction, parametrized by repulsion V, exchange interactions ${J}_{z}{,J}_{\ensuremath{\perp}},$ bond-charge interaction X, and hopping of pairs W. The case of correlated hopping, in which the hopping between nearest neighbors depends upon the occupation of the two sites involved, is also described by the model for sufficiently weak interactions. We study the model in one dimension with usual continuum-limit field theory techniques, and determine the phase diagram. For arbitrary filling, we find a very simple necessary condition for the existence of dominant triplet superconducting correlations at large distance in the spin SU(2) symmetric case: $4V+Jl0. $ In the correlated-hopping model, the three-body interaction should be negative for positive V. We also compare the predictions of this weak-coupling treatment with numerical exact results for the correlated-hopping model obtained by diagonalizing small chains and using a Berry phase to determine the opening of the spin gap.
Order determination and parameter estimation of multicomponent polynomial phase signals

AM-FM signals whose phases are polynomial functions of time are encountered in many communication and signal processing applications such as synthetic aperture radar (SAR) imaging, speech processing and mobile communications. This paper addresses the issue of parameter estimation of multicomponent polynomial phase signals (MC-PPS) embedded in noise. We focus on analyzing a general class of MC-PPS in the sense that we allow the components to have drastically different amplitudes and unknown phase orders and that we do not assume knowledge of the number of components. We show how existing techniques are inadequate in providing reliable estimates for such a broad class of MC-PPS, unless the components have similar amplitudes and the number of components and their phase orders are known. We then present a simple yet effective algorithm that obviates these stringent assumptions and uses a product high-order ambiguity function to estimate all the parameters in the MC-PPS. Numerical simulations are carried out that clearly illustrate the advantage of the proposed algorithm over existing techniques.
Electrochemical Sensor for the Determination of Methylthiouracil in Meat Samples

Two analytical methods based on miniaturized electrochemical sensors, voltammetric and amperometric sensors, have been developed for the determination of 6-methyl-2-thiouracil (MTU) in meat consumption samples (beef liver and foie). A multivariate approach has been considered to optimize the experimental procedure including extraction and electrochemical detection. Under optimal conditions and at a typical working potential of 1.55 V (vs Ag pseudo-reference electrode), response is linear in the range 0 to 20 µg L−1 MTU concentration range. The empirical limit of detection is 0.13 µg L−1, lower than the maximum concentration established by legislation. The electrochemical methods have been used to analyze MTU-spiked meat samples, and recovery values varying between 85 and 95% with coefficients of variation <30%. The analytical methods developed with the miniaturized electrochemical sensors can successfully determine the concentration of MTU in real meat samples with high accuracy, being the results obtained similar to those provided by other methods such as UV-Vis spectrophotometry. Finally, the degree of sustainability of the electrochemical sensors-based developed method has been quantified by means of the Analytical Eco-Scale.
RCW 36 in the Vela Molecular Ridge: Evidence for high-mass star-cluster formation triggered by cloud-cloud collision

A collision between two molecular clouds is one possible candidate for high-mass star formation. The HII region RCW 36, located in the Vela molecular ridge, contains a young star cluster with two O-type stars. We present new CO observations of RCW 36 with NANTEN2, Mopra, and ASTE using $^{12}$CO($J$ = 1-0, 2-1, 3-2) and $^{13}$CO($J$ = 2-1) line emissions. We have discovered two molecular clouds lying at the velocities $V_\mathrm{LSR} \sim$5.5 and 9 km s$^{-1}$. Both clouds are likely to be physically associated with the star cluster, as verified by the good spatial correspondence among the two clouds, infrared filaments, and the star cluster. We also found a high intensity ratio of $\sim$0.6-1.2 for CO $J$ = 3-2 / 1-0 toward both clouds, indicating that the gas temperature has been increased due to heating by the O-type stars. We propose that the O-type stars in RCW 36 were formed by a collision between the two clouds, with a relative velocity separation of 5 km s$^{-1}$. The complementary spatial distributions and the velocity separation of the two clouds are in good agreement with observational signatures expected for O-type star formation triggered by a cloud-cloud collision. We also found a displacement between the complementary spatial distributions of the two clouds, which we estimate to be 0.3 pc assuming the collision angle to be 45$^{\circ}$ relative to the line-of-sight. We estimate the collision timescale to be $\sim$10$^5$ yr. It is probable that the cluster age by Ellerbroek et al. (2013b) is dominated by the low-mass members which were not formed under the triggering by cloud-cloud collision, and that the O-type stars in the center of the cluster are explained by the collisional triggering independently from the low-mass star formation.
Data-driven fault detection of a 10 MW floating offshore wind turbine benchmark using kernel canonical variate analysis

Floating offshore wind turbines (FOWTs) can harvest more wind energy in deep water. However, due to their complex mechanical structure and harsh working conditions, various sensors, actuators, and components of FOWTs can malfunction and fail. To avoid serious accidents and reduce operation and maintenance costs, fault detection plays a critical role in wind-energy engineering, particularly for offshore wind energy. Because of complex characteristics, such as dynamics and nonlinearity, an accurate mathematical model cannot be easily obtained from first principles for FOWTs. In this paper, a new data-driven fault-detection method based on kernel canonical variable analysis (KCVA) is proposed for FOWTs. In the proposed method, the collected measurements are first augmented into time-lagged variables to capture the dynamics of FOWTs. The time-lagged variables are then mapped to a high-dimensional feature space to extract nonlinear features. Specifically, canonical variable analysis (CVA) is carried out to explore the correlations in high-dimensional feature space. For fault detection, two monitoring indexes including T 2 and squared prediction error ( SPE ) statistics are established. To verify the performance of the proposed KCVA-based fault-detection method, experiments on a high-fidelity FOWT benchmark, which was created from the National Renewable Energy Laboratory Fatigue, Aerodynamics, Structures, and Turbulence v8.0 simulator, were carried out. The results show the capability and efficiency of the proposed KCVA-based fault-detection method in comparison with other related methods.
Does CEO openness matter when explaining firm internationalization decisions: evidence from China

PurposeThe impact of executive characteristics on firm internationalization has already been extensively explored. However, relatively few studies have examined the critical role of chief executive officer (CEO) personality attributes, and especially CEO openness, in firm internationalization. This research aims to deepen the understanding of firm internationalization, by exploring whether and when CEO openness influences firm internationalization.Design/methodology/approachA sample of private high-tech listed firms in China is used, with data from 2004 to 2020.FindingsBased on upper echelons theory, this study theorizes and finds that CEO openness will positively influence firm internationalization. Further, based on the behavioral theory of the firm, this study finds that the performance aspiration gap weakens the positive effect of CEO openness on firm internationalization, but also finds that the potential slack strengthens this effect.Originality/valueFirst, the study reinterprets firm internationalization strategies from the perspective of CEO openness, a personality attribute; CEO openness is an important but so far rarely discussed topic in the field of international business. Second, for the first time, problemistic search and slack search into a research framework are introduced to explore the relationship between CEO characteristics and firm internationalization. This approach can further define the boundary conditions under which CEOs can project their values, preferences and personalities into the process of formulating and implementing a firm's internationalization strategy.
Constraining the population of intermediate-mass black holes by gamma-ray data of the Fornax cluster

Recent studies of merging black holes suggest that the cosmological mass fraction of primordial black holes (PBHs) is not completely negligible. The mass of a PBH can be as massive as an intermediate mass black hole (IMBH). In this article, we assume that dark matter particles are thermal relic particles and they can self-annihilate. The dark matter around an IMBH may have formed a density spike so that the rate of dark matter annihilation would be greatly enhanced. Using the gamma-ray data of the Fornax cluster and assuming merging events in the cluster are not important, we show that the amount of IMBHs (including PBHs) is very sub-dominant compared with the amount of baryons and dark matter. The upper limit on the IMBH-to-baryon ratio is $\sim 7\times 10^{-4}$ for $m_{\rm DM} \le 10$ TeV.
Using the Bootstrap as an Aid in Choosing the Approximate Representation for Vector Time Series

In this article, a procedure is presented to use the bootstrap in choosing the best approximation in terms of forecasting performance for the equivalent state-space representation of a vector autoregressive model. It is found that the proposed procedure, which uses each approximant's forecasting performance, can enhance considerably an approach based simply on the estimated Hankel singular values.
The X-ray spectrum of the atoll source 4U 1608—52

The transient atoll source 4U 1608−52 was extensively observed by the Rossi X-ray Timing Explorer (RXTE) during its 1998 outburst. We analyse its X-ray spectra as a function of inferred accretion rate from both the 1998 outburst and the 1996 and 1998 non-outburst data. We can fit all the spectra by a model in which seed photons from the neutron star surface are Comptonized in a boundary layer. The Comptonized emission illuminates the accretion disc surface, producing an ionized, relativistically broadened reflection signature, while the direct emission from the accretion disc can also be seen. The evolution of the source can be explained if the main parameter driving the spectral evolution is the average mass accretion rate, which determines the truncation radius of the inner accretion disc. At low mass accretion rates, in the island state, the disc truncates before reaching the neutron star surface and the inner accretion flow/boundary layer is mostly optically thin. The disc emission is at too low a temperature to be observed in the RXTE spectra, but some of the seed photons from the neutron star can be seen directly through the mostly optically thin boundary layer. At higher mass accretion rates, in the banana state, the disc moves in and the boundary layer becomes much more optically thick so its temperature drops. The disc can then be seen directly, but the seed photons from the neutron star surface cannot, as they are buried beneath the increasingly optically thick boundary layer.
Vitamin D Deficiency and COVID-19: A Biological Database Study on Pathways and Gene-Disease Associations

Vitamin D (VD) is a fat-soluble vitamin, and pivotal for maintaining health. Several genetic markers have been related to a deficient VD status; these markers could confer an increased risk to develop osteoporosis and other chronic diseases. A VD deficiency could also be a determinant of a severe COVID-19 disease. This study aimed to interrogate genetic/biological databases on the biological implications of a VD deficiency and its association with diseases, to further explore its link with COVID-19. The genetic variants of both a VD deficiency and COVID-19 were identified in the genome-wide association studies (GWAS) catalog and other sources. We conducted enrichment analyses (considering corrected p-values < 0.05 as statistically significant) of the pathways, and gene-disease associations using tools, such as FUMA, REVIGO, DAVID and DisGeNET, and databases, such as the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO). There were 26 and 46 genes associated with a VD deficiency and COVID-19, respectively. However, there were no genes shared between the two. Genes related to a VD deficiency were involved in the metabolism of carbohydrates, retinol, drugs and xenobiotics, and were associated with the metabolic syndrome and related factors (obesity, hypertension and diabetes mellitus), as well as with neoplasms. There were few enriched pathways and disease connections for the COVID-19-related genes, among which some of the aforementioned comorbidities were also present. In conclusion, genetic factors that influence the VD levels in the body are most prominently associated with nutritional and metabolic diseases. A VD deficiency in high-risk populations could be therefore relevant in a severe COVID-19, underlining the need to examine whether a VD supplementation could reduce the severity of this disease.