Miracle-dz/UniFAR-FTUs huggingface dataset:
A new validation scheme for the evaluation of multiparameter fields

On the basis of an extended cluster analysis algorithm, we present a new validation method for the evaluation of simulation experiments characterized by more than one parameter. This method allows the assessment of any parameter combination in space and time. As an example for the effectiveness of the algorithm, the results of two regional climate model runs and observational data have been tested and interpreted.
Effects of Caloric Restriction on Spatial Object Recognition Memory, Hippocampal Neuron Loss and Neuroinflammation in Aged Rats

Age-related neurobiological changes significantly affect hippocampal structure and function, such that the main cognitive impairments associated with aging are related to the integrity of this brain structure, including the deterioration in spatial object recognition (SOR) memory. Previous studies have shown that intrinsic factors such as neuroinflammation, as well as lifestyle factors such as diet, can affect aging-associated brain functions and cognitive performance. In this regard, caloric restriction (CR) produces beneficial effects on health and life expectancy, although its ability to slow down age-dependent effects on cognitive decline and hippocampus (HPC) functioning remains unclear. Therefore, we set out to evaluate the effects of CR on SOR memory in aged male Wistar rats, as well as those on hippocampal neuron loss, neurogenesis and inflammation. The data show that CR in aged rats attenuates the decline in SOR memory, age-associated hippocampal neuron loss, and age-dependent microglial activation. Furthermore, we found a significant reduction in neurogenesis in the dentate gyrus of the old animals relative to adult rats. These findings support the positive effect of CR on SOR memory, suggesting that it dampens hippocampal neuronal loss and reduces proinflammatory activity.
Adaptive Approach for Boundary Effects Reduction in Rotating Machine Signals Analysis

Boundary effects are caused by incomplete data in the boundary regions when the analysis window gets closer to the edge of a signal. Various extension schemes have been developed to handle the boundaries of finite length signals to reduce the boundary effects. Zero padding, periodic extension, and symmetric extension are some basic extension methods. However, these solutions have drawbacks. In this paper, we consider the problem of handling the boundary effects due to improper extension methods in the wavelet transform for the application of fault diagnosis of rotating machine. An extension algorithm based on curve fitting with properties that make it more suitable for boundary effects reduction is presented. This extension algorithm could preserve the time-varying characteristics of the signals and be effective to reduce distortions appearing at the boundary. Then, an interpolation approach is used in the boundary effects region to further alleviate the distortions. Procedures for realization of these two algorithms and relative issues are presented. Several experimental tests show that the proposed algorithms are efficient to alleviate the boundary effects in comparison to the existing extension methods.
Strings from gravity

The quantum properties of black holes are compared with those of elementary and composite particles. As argued before by this author, it is desirable to search for a theory of black holes in which quantum mechanical "information" is not drained away by the horizon, but such a theory requires a drastically new approach in formulating general coordinate transformations with horizons in a quantum theory. It is subsequently shown that a closed string with string tension T = 1/8πG reproduces in a remarkable way the horizon fluctuations so that a new geometric interpretation of strings is suggested.
Rapamycin Alleviates Protein Aggregates, Reduces Neuroinflammation, and Rescues Demyelination in Globoid Cell Leukodystrophy

We have shown in vivo and in vitro previously that psychosine causes dysfunction of autophagy and the ubiquitin-proteasome system underlying the pathogenesis of globoid cell leukodystrophy (GLD), a devastating lysosomal storage disease complicated by global demyelination. Here, we investigated the therapeutic efficacy of the mTOR inhibitor rapamycin in twitcher mice, a murine model of infantile GLD, in biochemical, histochemical, and clinical aspects. Administration of rapamycin to twitcher mice inhibited mTOR signaling in the brains, and significantly reduced the accumulation of insoluble ubiquitinated protein and the formation of ubiquitin aggregates. The astrocytes and microglia reactivity were attenuated in that reactive astrocytes, ameboid microglia, and globoid cells were reduced in the brains of rapamycin-treated twitcher mice. Furthermore, rapamycin improved the cortical myelination, neurite density, and rescued the network complexity in the cortex of twitcher mice. The therapeutic action of rapamycin on the pathology of the twitcher mice’s brains prolonged the longevity of treated twitcher mice. Overall, these findings validate the therapeutic efficacy of rapamycin and highlight enhancing degradation of aggregates as a therapeutic strategy to modulate neuroinflammation, demyelination, and disease progression of GLD and other leukodystrophies associated with intracellular aggregates.
Probing the homogeneity of the isotopic composition and molar mass of the ‘Avogadro’-crystal

Improved measurements on silicon crystal samples highly enriched in the 28Si isotope (known as ‘Si28’ or AVO28 crystal material) have been carried out at PTB to investigate local isotopic variations in the original crystal. This material was used for the determination of the Avogadro constant NA and therefore plays an important role in the upcoming redefinition of the SI units kilogram and mole, using fundamental constants. Subsamples of the original crystal have been extensively studied over the past few years at the National Research Council (NRC, Canada), the National Metrology Institute of Japan (NMIJ, Japan), the National Institute of Standards and Technology (NIST, USA), the National Institute of Metrology (NIM, People’s Republic of China), and multiple times at PTB. In this study, four to five discrete, but adjacent samples were taken from three distinct axial positions of the crystal to obtain a more systematic and comprehensive understanding of the distribution of the isotopic composition and molar mass throughout the crystal. Moreover, improved state-of-the-art techniques in the experimental measurements as well as the evaluation approach and the determination of the calibration factors were utilized. The average molar mass of the measured samples is M = 27.976 970 12(12) g mol−1 with a relative combined uncertainty uc,rel(M) = 4.4 ×10−9. This value is in astounding agreement with the values of single samples measured and published by NIST, NMIJ, and PTB. With respect to the associated uncertainties, no significant variations in the molar mass and the isotopic composition as a function of the sample position in the boule were observed and thus could not be traced back to an inherent property of the crystal. This means that the crystal is not only ‘homogeneous’ with respect to molar mass but also has predominantly homogeneous distribution of the three stable Si isotopes.
Image reconstruction from partial pseudo polar Fourier sampling based on alternating direction total variation minimization

Linear scan Computed Tomography (LCT) has emerged as a promising technique in fields like industrial scanning and security inspection due to its straight-line source trajectory and high scanning speed. However, in practical applications of LCT, the ordinary algorithms suffer from serious artifacts owing to the limited-angle and insufficient data. In this paper, a new method which reconstructs image from partial Fourier data sampled in pseudo polar grid based on alternating direction anisometric total variation minimization has been proposed. The main idea is to reform the image reconstruction problem into solving an under-determined linear equation, and then reconstruct image by applying the popular total variation (TV) minimization to reform an unconstraint optimization by means of augmented Lagrange method and using the alternating minimization method of multiplier (ADMM) which contributes to the fast convergence. The proposed method is practical in the large-scale task of reconstruction due to its algorithmic simplicity and computational efficiency and reconstructs better images. The results of the numerical simulations and pseudo real data reconstructions from the linear scan validate that the proposed method is both efficient and accurate.
Evidence for vhe gamma-ray emission from the distant bl lac pg 1553+113

The high-frequency peaked BL Lac PG 1553+113 was observed in 2005 with the H.E. S.S. stereoscopic array of imaging atmospheric-Cherenkov telescopes in Namibia. Using the H.E. S.S. standard analysis, an excess was measured at the 4.0 sigma level in these observations (7.6 hours live time). Three alternative, lower-threshold analyses yield >5 sigma excesses. The observed integral flux above 200 GeV is (4.8 +/- 1.3_{stat} +/- 1.0_{syst}) x10^{-12} cm^{-2} s^{-1}, and shows no evidence for variability. The measured energy spectrum is characterized by a very soft power law (photon index of Gamma=4.0 +/- 0.6). Although the redshift of PG 1553+113 is unknown, there are strong indications that it is greater than z=0.25 and possibly larger than z=0.78. The observed spectrum is interpreted in the context of VHE gamma-ray absorption by the Extragalactic Background Light, and is used to place an upper limit on the redshift of z<0.74.
Academic Writing of Saudi Graduate Students: Issues and Improvements

This study investigates research writing difficulties encountered by Saudi graduate students at a Saudi university and seeks to offer interventional guidelines accordingly. A fuller understanding of these difficulties will contribute to the development of instruction aimed at improving students’ research writing skills. The main question this study addresses is this: What are the major academic writing problems facing Saudi graduate students? The investigation used an explanatory sequential mixed methods approach involving 87 participants at the University of Jeddah, Saudi Arabia. The data were collected through a 20-item Likert scale questionnaire completed online by 85 Saudi graduate students (37 males, 48 females; 69 majoring in English, 16 majoring in other subjects) and semi-structured interviews conducted with two faculty members. The quantitative data were analyzed statistically using the Statistical Package for Social Sciences (SPSS), and the qualitative data were analyzed thematically. Results revealed that most students experienced difficulties related to language, argumentation, and research-article genre when composing research reports in English. Both the participating students and teachers thought the most serious academic writing challenges for Saudi graduate students were presenting complex information in clear sentences and building strong arguments. In contrast, the least problematic task was finding and documenting sources. Regarding evaluating sources, writing Literature reviews, and using technical vocabulary, most students were unsure of their abilities. Besides, English majors and other majors had similar perceptions of difficulties in three out of four significant aspects of research writing. As far as documenting sources is concerned, the perception varied significantly between the English-major and other-major students. The findings of the present study can assist stakeholders in identifying instructional needs in research writing in the Saudi Arabian context, and our guidelines will make research writing less difficult for Saudi students.
Direct Methods for Solving Singular Nonlinear Equations

A class of Newton-type methods for computing singular points with corank > 1 and index > 0 is presented. The idea is to use a generalized Sherman- Morrison formula to define a regularizing perturbation of the Newton-increment formula. The quadratic convergence of the process is preserved. The proposed approach may be linked to tensor methods, bordered Jacobian techniques, and numerical Liapunov-Schmidt reduction.
Simple solutions for hyperbolic and related position fixes

Navigation fixed from range differences to three stations and an additional piece of information are investigated. It is shown that if the additional information is the navigator altitude, or the range difference to a fourth station, the computation of the navigation fix is reduced to finding the roots of a quadratic. If the additional information is the range to another station, or that the navigator is on the Earth ellipsoid, the fix can be obtained by solving a quartic. By emphasizing the underlying geometric interpretations, these fixes and their simple solutions are made clear. The derivations also show that the same solution algorithms are applicable if the basic navigation measurements are range sums instead of range differences. >
Near-Inertial Oscillations of Geophysical Surface Frontal Currents

Intrinsic oscillations of stable geophysical surface frontal currents of the unsteady, nonlinear, reduced-gravity shallow-water equations on an f plane are investigated analytically and numerically. For frictional (Rayleigh) currents characterized by linear horizontal velocity components and parabolic cross sections, the primitive equations are reduced to a set of coupled nonlinear ordinary differential equations. In the inviscid case, two periodic analytical solutions of the nonlinear problem describing 1) the inertially reversing horizontal displacement of a surface frontal current having a fixed parabolic cross section and 2) the cross-front pulsation of a coastal current emerging from a motionless surface frontal layer are presented. In a linear and in a weakly nonlinear context, analytical expressions for field oscillations and their frequency shift relative to the inertial frequency are presented. For the fully nonlinear problem, solutions referring to a surface frontal coastal current are obtained analytically and numerically. These solutions show that the currents oscillate always superinertially, the frequency and the amplitude of their oscillations depending on the magnitude of the initial disturbance and on the squared current Rossby number. In a linear framework, it is shown that disturbances superimposed on the surface frontal current are standing waves within the bounded region, the frequencies of which are inertial/ superinertial for the first mode/higher modes. In the same frame, a zeroth mode, which could be interpreted as the superposition of an inertial wave on a background vorticity field, would formally yield subinertial frequencies. For surface frontal currents affected by Rayleigh friction, it is shown that the magnitude of the mean current decays according to a power law and that the oscillations decay faster, because this decay follows an exponential law. Implications of the intrinsic oscillations and of their rapid dissipation for the near-inertial motion in an active ambient ocean are discussed.
Initial Response of Pentaerythritol Tetranitrate (PETN) under the Coupling Effect of Preheating, Shock and Defect via the Molecular Dynamics Simulations with the Multiscale Shock Technique Method

The initial response of PETN under the coupling of preheating, impact and defects was simulated by Multiscale Shock Technique (MSST) method and molecular dynamics. The temperature change of PETN during impact compression can be divided into three stages: (1) the elastoplastic change of the system caused by initial compression; (2) part of PETN decomposes and releases energy to raise temperature; (3) a secondary chemical reaction occurs, resulting in rapid temperature rise. Under the given conditions, a higher initial preheating temperature will lead to faster decomposition of PETN; The existence of defects will accelerate the decomposition of PETN molecules; Coupling the highest preheating temperature with defects will lead to the fastest decomposition of PETN molecules, while in the defect-free PETN system with a preheating temperature of 300 K, the decomposition of PETN molecules is the slowest. For the case of Us = 8 km·s−1, the effect of defects on the initial PETN reaction is greater than the initial preheating temperature; When the impact velocity is greater than 9 km·s−1, the impact velocity is an important factor affecting the decomposition of PETN molecules. For Us = 10 km·s−1, NO2 is the main initial product in the defective PETN crystal, while in the perfect PETN crystal, it is the combination of NO2 and HONO. The chemical reaction kinetics analysis shows that the preheating temperature and defects will accelerate the decomposition of PETN. The higher the preheating temperature, the faster the decomposition of PETN. For the case of Us = 7 km·s−1, 8 km·s−1 and 9 km·s−1, the existence of defects will increase the decomposition rate by more than 50% regardless of the initial preheating temperature. In the case of Us = 10 km·s−1, the improvement of decomposition rate by defects is not as significant as the initial preheating temperature.
Watch-Type Dual-Mode Wearable Health Device

Wearable devices can be found as numerous types of health devices ranging from monitoring hazardous environments to detecting physiological signals. Its utilities have also shown encouraging improvements toward personalized healthcare. Thus, many kinds of wearable health devices (WHD) have been reported and developed. Those reports highlight their efficiency in monitoring harmful environmental factors and various diseases for diagnostic and treatment purposes. This paper proposes a watch-type of dual-mode WHD that can perform gaseous phase detection to monitor dangerous environmental situations such as bad air quality and aqueous phase detection to measure physiological signals from human sweat or blood. The proposed system was fabricated on a printed circuit board and its size is 3 cm × 3 cm which is suitable as a wearable device. It also consumes very low power and has capabilities of wired/wireless charging and wired/wireless communication. Furthermore, customized windows and Android applications have been developed to visualize obtained data in a user’s computer or smartphone. The system was tested both electrically and chemically and showed promising results as the WHD.
Influence of a piezoelectric field on the electron distribution in a double GaN/Al0.14Ga0.86N heterojunction

C–V profiling of Al0.14Ga0. 86N/GaN heterojunctions was performed. It was found that a heterojunction with the Al0.14Ga0. 86N layer on top increases the electron concentration at the Al0.14Ga0. 86N/GaN interface, while the reversed structure with the GaN layer on top decreases it. In accordance with this result, an Al0.14Ga0. 86N/GaN double heterojunction was found to experience a strongly asymmetric electron distribution with an enhancement of the electron concentration at the interface closest to the sample surface. This effect is attributed to the presence of a piezoelectric field redistributing the electrons in the heterostructure.
Intra-Class Universal Adversarial Attacks on Deep Learning-Based Modulation Classifiers

Most existing adversarial attack methods generally rely on ideal assumptions, which is unreasonable for practical applications. In this letter, a practical threat model which utilizes adversarial attacks for anti-eavesdropping is proposed and a physical intra-class universal adversarial perturbation (IC-UAP) crafting method against DL-based wireless signal classifiers is then presented. First, an IC-UAP algorithm is proposed based on the threat model to craft a stronger UAP attack against the samples in a given class from a batch of samples in the class. Then, we develop a physical attack algorithm based on the IC-UAP method, in which perturbations are optimized under random shifting to enhance the robustness of IC-UAPs against the unsynchronization between adversarial attacks and attacked signals. Finally, the numerical results corroborate the effectiveness of the proposed approach based on the benchmark dataset.
On the robust estimation of cumulants

Robust estimation of location algorithms are employed to estimate the third order cumulants of various lags from simulated signals representing the zero mean Uniform and Gaussian distributions (as examples of symmetric distributions). It is demonstrated that the biweight, wave, and median estimators provide consistent cumulant estimates of less variance than the (most common) mean estimator. This solves the problem with regard to symmetric distributions as these robust estimators have been designed for symmetric distribution. When these are applied to asymmetric distributions, biweight and wave estimators appear to give encouraging results. Further work with the particular emphasis on the estimation from asymmetric distributions is under way. <<ETX>>
Variants of chi-square for 2 × 2 contingency tables

Four variants of the chi-square statistic are evaluated in terms of their adequacy as tests of association in 2 × 2 contingency tables. When both sets of marginal totals are fixed in advance, none of these variants is wholly satisfactory, even with moderately large samples. When one set of marginal totals is fixed in advance while the other is free to vary, or when neither set of marginal totals is fixed in advance, a variant of chi-square proposed by Upton (1982) is to be preferred both theoretically and in practice. The variant proposed by Yates (1934) which incorporates a correction for continuity and which is often recommended in statistics textbooks is theoretically unsound, shows an extremely conservative bias, and lacks sufficient power.
Bandwidth Tunable and Compact Band-Pass Filter (BPF) Using Complementary Split Ring Resonators (CSRRS) on Substrate Integrated Waveguide (SIW)

In this paper, we present a novel bandwidth tunable bandpass filter (BPF) loaded by complementary split ring resonators (CSRRs). On substrate integrated waveguide (SIW), the CSRRs are modeled and deployed to implement BPFs with tunable bandwidth capability. The microwave tunable circuits are designed in order to observe the various coupling coefficients and external quality factors by changing the orientations of the CSRRs. Four different configurations of filters are proposed and fabricated. These structures provide compact size as well as high frequency selectivity due to the use of the subwavelength resonators preserving sharp rejection and an evanescent wave propagation mode below the waveguide cutoff. Attractive performances of tunable BPFs are validated theoretically and experimentally.
Heparin in Acid and Alkaline Environments—A Study of the Correlations between Hydrodynamic Properties and Desulphation

This work evaluated the hydrodynamic properties of heparin hydrolysed at temperatures ranging from 40 °C to 80 °C in buffered acid and alkaline environments. The correlation between hydrodynamic parameters led to the conclusion that polymer conformational changes appeared to be minimal until chain depolymerisation, initiated at pH 1 and 80 °C. However, the synergy of conformational changes, even if minimal, and sulphate loss observed at pH 1, pH 3 and pH 12 (various temperatures) resulted in a loss of the antifactor Xa activity. Therefore, the ‘contribution’ of conformational changes should be added to the generally recognized effect of desulphation towards the activity of heparin. This is of significance as the processing of medical heparin is complex, and requires adjustment of several physical and chemical factors, including pH and temperature.