Miracle-dz/UniFAR-FTUs huggingface dataset:
Reflection and refraction of waves at the interface of an isotropic medium over a highly anisotropic medium

In this paper, we have considered the reflection and refraction of a plane wave at an interface between two half-spaces. The lower half-spaces is composed of highly anisotropic triclinic crystalline material and the upper half-space is homogeneous and isotropic. It has been assumed that due to incidence of a plane quasi-P (qP) wave, three types of waves, namely, quasi-P (qP), quasi-SV (qSV) and quasi-SH (qSH), will be generated in the lower half space whereas P and S waves will be generated in the upper half space. The phase velocities of all the quasi waves have been calculated. It has been assumed that the direction of particle motion is neither parallel nor perpendicular to the direction of propagation. Some specific relations have been established between directions of motion and propagation, respectively. The expressions for reflection coefficients of qP, qSV, qSH and refracted coefficients of P and SV waves are obtained. Results of reflection and refraction coefficients are presented.
A new connectivity model for unmanned aerial vehicle communications and flying height optimization

This paper presents a new connectivity model for unmanned aerial vehicle (UAV) communications. We present closed‐form formulas for the probability of line‐of‐sight as a function of UAV height and distance to a ground based receiver, based on a two‐dimensional model of building and UAV locations. We show that our formulas exactly match Monte‐Carlo simulated values, whereas the existing approach over‐predicts by a factor of 2 to 3. We use the model to optimize the flying height for a UAV deployed as a mobile base station, where the goal is to maximize the number of possible connected users. We observe that the optimal height has a log‐linear characteristic. We use this to present a closed‐form formula for optimal height. We show that our techniques predict the height within 4% of realistic Monte‐Carlo simulations, and significantly outperform existing approaches which are shown to over‐predict by 40%–50%.
Testing homogeneity of the multinomial proportions

Abstract In this article, we investigate some statistical procedures for testing homogeneity in a multinomial population. First we focus on the simpler problem of testing homogeneity in the entire vector of multinomial proportions. When the null hypothesis of uniformity is violated, some of the cell frequencies will tend to be small and some will tend to be large. We propose to investigate the performance of tests based on X(k) = max {X1, . , Xk} or X(1) = min {X1, . , Xk}, which are functions of the minimal sufficient statistics for this problem. The performance of the likelihood ratio test implemented by the asymptotic chi-square distribution and the simulated exact distribution will be compared to a test which is based on the maximum, the minimum, the pair maximum and minimum, the range, and the ratio statistic: X(k)/X(1). We also investigate the more difficult problem of testing homogeneity of a subset of the p-vector. For this problem, we focus only on likelihood ratio tests and investigate two implementations. Simulation studies are presented to evaluate the accuracy of achieving the targeted significance level and to compare the powers of the test statistics mentioned above for a range of alternatives. Based on the numerical results, recommendations are given for employing these testing procedures.
Voltage-Dependent Anion Channel 1 Expression in Oral Malignant and Premalignant Lesions

Background: The voltage-dependent anion channel 1 protein (VDAC1) plays a role in cellular metabolism and survival. It was found to be down or upregulated (overexpressed) in different malignancies but it was never studied in application to oral lesions. The purpose of this study was to retrospectively evaluate the expression of VDAC1 in biopsies of oral premalignant, malignant, and malignancy-neutral lesions and to examine the possible correlations to their clinicopathological parameters. Materials and methods: 103 biopsies including 49 oral squamous cell carcinoma, 33 epithelial dysplasia, and 21 fibrous hyperplasia samples were immunohistochemically stained with anti-VDAC1 antibodies for semi-quantitative evaluation. The antibody detection was performed with 3,3′-diaminobenzidine (DAB). The clinicopathological information was examined for possible correlations with VDAC1. Results: VDAC1 expression was lower in oral squamous cell carcinoma 0.63 ± 0.40 and in oral epithelial dysplasia 0.61 ± 0.36 biopsies compared to fibrous hyperplasia biopsies 1.45 ± 0.28 (p < 0.01 for both; Kruskal–Wallis test). Conclusion: Oral squamous cell carcinoma and epithelial dysplasia tissues demonstrated decreased VDAC1 protein expression if compared to fibrous hyperplasia samples, but were not different from each other, suggesting that the involvement of VDAC1 in oral carcinogenesis is an early stage event, regulating cells to live or die.
Zinc and Strontium-Substituted Bioactive Glass Nanoparticle/Alginate Composites Scaffold for Bone Regeneration

The global population is growing older and entering an aging society. Aging results in severe tissue disorder and organ dysfunction. Bone-related injuries are particularly significant. The need for alternative bone replacement materials for human implants has grown over the past few decades. Alginate has the potential for use as a cell scaffold for bone tissue engineering due to its high bio-compatibility. To improve the bioactivity of alginate scaffolds, zinc- and strontium-containing sol-gel-derived bioactive glass nanoparticles (Zn-Sr-BGNPs) with sizes ranging from 100 to l40 nm were incorporated. Zn-Sr-BGNPs synthesized through the sol-gel process have a high sur-face-to-volume ratio, homogeneity, and purity, resulting in faster degradation. The therapeutic bivalent ions released from Zn-Sr-BGNPs strengthen the cell scaffold and improve the stimulation of the production and development of bone cells. Zn-Sr-BGNPs with different Zn to Si nominal ratios of 0, 1, and 1.5 were mixed with alginate in this research. The ratio of Zn in Zn-Sr-BGNPs and the ratio of Zn-Sr-BGNPs in scaffolds impact the pore size, swelling, and biological properties of synthesized composite scaffolds. The surface area and pore volume of a 1:1 1Zn-Sr-BGNP:Alg composite scaffold were 22.58 m2/g and 0.055 cm3/g, respectively. The incorporation of Zn-Sr-BGNPs improved the mechanical performance of the scaffolds up to 4.73 ± 0.48 MPa. The swelling rate decreased slightly from 2.12 (pure Alg) to 1.50 (1Zn-Sr-BGNP:Alg (1:1)). The 1Zn-Sr-BGNP:Alg (1:1) composite scaffold promoted bioactivity through apatite layer formation, increased bone cell proliferation via the dissolution products released from the scaffold, enhanced calcium deposition, and facilitated cell attachment. Thus, 1Zn-Sr-BGNP:Alg (1:1) composite scaffold is proposed as a possible artificial bone scaffold in bone tissue regeneration.
Generalized quantile regression

Generalized quantile regressions, including the conditional quantiles and expectiles as special cases, are useful alternatives to the conditional means for characterizing a conditional distribution, especially when the interest lies in the tails. We denote vn(x) as the kernel smoothing estimator of the expectile curves. We prove the strong uniform consistency rate of vn(x) under general conditions. Moreover, using strong approximations of the empirical process and extreme value theory, we consider the asymptotic maximal deviation sup06x61 |vn(x)− v(x)|. According to the asymptotic theory, we construct simultaneous confidence bands around the estimated expectile function. We develop a functional data analysis approach to jointly estimate a family of generalized quantile regressions. Our approach assumes that the generalized quantiles share some common features that can be summarized by a small number of principal components functions. The principal components are modeled as spline functions and are estimated by minimizing a penalized asymmetric loss measure. An iteratively reweighted least squares algorithm is developed for computation. While separate estimation of individual generalized quantile regressions usually suffers from large variability due to lack of sufficient data, by borrowing strength across data sets, our joint estimation approach significantly improves the estimation efficiency, which is demonstrated in a simulation study. The proposed method is applied to data from 150 weather stations in China to obtain the generalized quantile curves of the volatility of the temperature at these stations.
Waldsteinia within Geum s.l. (Rosaceae): Main Aspects of Phylogeny and Speciation History

Waldsteinia is a small plant genus inhabiting the temperate regions of the Northern Hemisphere. According to the latest revisions, Waldsteinia is included in Geum. We have obtained a phylogenetic reconstruction based on the nuclear (ITS) and plastid (trnL-trnF) DNA to understand the phylogenetic structure of Waldsteinia and its relationships with other taxa of Geum s.l. Phylogenetic analysis based on the joint ITS + trnL-trnF dataset demonstrated Waldsteinia monophyly. The phylogenetic relationships of Waldsteinia species were better explained by their geographical distribution than their morphology. Hence, Euro-Siberian, Northeast Asian, and North American phylogeographic groups were distinguished, with East Asia having been suggested as the place of Waldsteinia origin. Considering the incongruence in W. geoides (a type species) position on the plastid and nuclear DNA trees, together with the discrepancy between the species morphology and its location on the plastid DNA tree, a hybrid origin was suggested for this species. Despite the fact that the position of W. maximowicziana is still not fully resolved, we support the point of view that claims it should be separated from the W. ternata aggregate (traditionally including W. trifolia, W. ternata s.str., and W. maximowicziana) and considered a separate species. The American W. doniana, W. fragarioides, and W. lobata belong to a single maternal lineage, but the observed genetic differences are too small to serve as a convincing argument for species segregation, so their relationships still remain unresolved.
Assessment of the Potential Role of Selected Single Nucleotide Polymorphisms (SNPs) of Genes Related to the Functioning of Regulatory T Cells in the Pathogenesis of Psoriasis

Recent studies have indicated a key role of the impaired suppressive capacity of regulatory T cells (Tregs) in psoriasis (PsO) pathogenesis. However, the genetic background of Treg dysfunctions remains unknown. The aim of this study was to evaluate the association of PsO development with selected single nucleotide polymorphisms (SNPs) of genes in which protein products play a significant role in the regulation of differentiation and function of Tregs. There were three study groups in our research and each consisted of different unrelated patients and controls: 192 PsO patients and 5605 healthy volunteers in the microarray genotyping group, 150 PsO patients and 173 controls in the ARMS–PCR method group, and 6 PsO patients and 6 healthy volunteers in the expression analysis group. The DNA microarrays analysis (283 SNPs of 57 genes) and ARMS–PCR method (8 SNPs in 7 genes) were used to determine the frequency of occurrence of SNPs in selected genes. The mRNA expression of selected genes was determined in skin samples. There were statistically significant differences in the allele frequencies of four SNPs in three genes (TNF, IL12RB2, and IL12B) between early-onset PsO patients and controls. The lowest p-value was observed for rs3093662 (TNF), and the G allele carriers had a 2.73 times higher risk of developing early-onset PsO. Moreover, the study revealed significant differences in the frequency of SNPs and their influence on PsO development between early- and late-onset PsO. Based on the ARMS–PCR method, the association between some polymorphisms of four genes (IL4, IL10, TGFB1, and STAT3) and the risk of developing PsO was noticed. Psoriatic lesions were characterized with a lower mRNA expression of FOXP3, CTLA4, and IL2, and a higher expression of TNF and IL1A in comparison with unaffected skin. In conclusion, the genetic background associated with properly functioning Tregs seems to play a significant role in PsO pathogenesis and could have diagnostic value.
Performance analysis and design of circular high‐strength concrete‐filled double‐skin aluminum tubular short columns under axial loading

This study investigates the performance and design of high‐strength circular concrete‐filled double‐skin aluminum tubular (CFDAT) columns under axial loading. A new fiber element (FBE) model incorporating a new lateral confinement model is developed that considers the confinement effects and material nonlinearities. A new strength degradation factor is proposed for determining the postpeak behavior of the confined concrete in CFDAT circular columns. Existing experimental results are used to validate the accuracy of the predicted ultimate strength and axial load‐strain ( P−ε ) curves of CFDAT columns under axial loading. A comparison of the predictions of the ultimate strength and P−ε curves of CFDAT columns using the proposed lateral confinement model is made against the prediction using the three‐dimensional finite element modeling and the existing lateral pressure model of CFDAT columns proposed by other researchers. The performance of the CFDAT columns under axial loading is investigated using a detailed parametric study. The accuracy of existing empirical formulas given in various design standards for conventional concrete‐filled steel tubular columns as well as given by another researcher in predicting the ultimate strength of CFDAT columns is examined. Finally, a simple design formula is proposed and validated against the experimental and numerical results obtained from this study. It is found that the proposed FBE model and the simplified model developed in this study can accurately predict the performance of CFDAT columns under axial loading.
Exploring international customers’ luxury service experiences during the COVID-19 pandemic

During the COVID-19 pandemic and the associated strain on consumption activities, demand for luxury hotels has risen steadily as a safe way to enjoy leisure services. This study aims to examine the consequences of congruence and identification. An online survey generating 315 datasets from international customers of luxury hotel services is conducted. Partial least squares structural equation modeling is used to test the hypotheses. The results demonstrate that perceived brand authenticity by customers influences both revisit and word-of-mouth intentions via engagement. Also, brand congruence leads to customer engagement with luxury hotel services and word-of-mouth intention. In contrast, no direct impact of congruence on revisit intention was found. Results regarding the effects of brand authenticity and congruence demonstrate that luxury service brands have the potential to influence customers’ patronage behaviors through different approaches. The findings confirm the importance of engagement with brands in the luxury service setting.
Electron scattering from CO below resonance energy

Absolute differential cross sections for elastic scattering and vibrational excitation of CO by electron impact are presented. The electron collision energy reaches from 1.5 eV down to threshold, the covered angular range lies between 5 degrees and 110 degrees . By comparing the measured angular and energy dependences with theoretical models, contributions of different interactions to the differential cross section are evaluated. For the elastic cross section, the existing value of 0.7 a0 for the scattering length of CO is in agreement with the authors experimental results. Finally, integrated cross sections for the vibrational excitation process are found to differ substantially from electron swarm results.
Optimization of the Crystallization Process of TFA-MOD ErBCO Films on IBAD-Substrate Under Low-Pressure Conditions via DSD Approach

Crystallization in a sub-atmospheric reactor could achieve higher production rate while dramatically reducing the flow rate of high-purity carrier gas. Due to enhanced supersaturation conditions at low total pressure, it is necessary to find the optimum processing window to avoid misoriented growth. This is extensive and incomplete when using one-factor-at-a-time experiments as significant parameters are often correlated. We prepared ErBa<sub>2</sub>Cu<sub>3</sub>O<sub>7-</sub><italic><sub>δ</sub></italic> (ErBCO) films by the TFA-MOD route with low-fluorine solutions on technical IBAD template with CeO<sub>2</sub> top buffer layer in an industrial reel-to-reel furnace. We used a novel design-of-experiment (DOE) technique, the Definitive Screening Design (DSD), to identify significant factors for improving critical temperature and microstructure of the films. Within the investigated range, lower crystallization temperature as well as lower total pressure are beneficial. With the new process window, the self-field critical current density at 77 K was successfully increased from almost zero to 1 MA/cm<sup>2</sup>. This shows that DSD is an attractive approach to optimize the CSD process under low-pressure conditions to enhance the growth rate or possibly achieve a reduction of carrier gas flow rate by a factor <italic>p</italic><sub>tot</sub>/<italic>p</italic><sub>atm</sub> of 3.3 for equal output as the atmospheric reactor. Further improvement of <italic>J</italic><sub>c</sub> is necessary and possible.
The High-Risk Profile of Selective Growth Restriction in Monochorionic Twin Pregnancies

The present review aims to provide a critical appraisal of the sonographic diagnosis and follow-up and to evaluate the optimal clinical management of monochorionic twin pregnancies where one of the twins is complicated by selective fetal growth restriction (sFGR). The classification is based on the umbilical artery (UA) diastolic flow reflecting the outcome. If the sFGR twin has positive diastolic flow (Type I) then the prognosis is good, and it does not require close surveillance. Biweekly or weekly sonographic and Doppler surveillance and fetal monitoring are recommended strategies to detect unpredictable complications in type II and type III forms, which are defined by persistently absent/reverse end-diastolic flow (AREDF) or cyclically intermittent absent/reverse end-diastolic flow (iAREDF) in the umbilical waveforms, respectively. The latest forms are associated with an increased risk of unexpected fetal demise of the smaller twin and 10–20% risk of neurological injury in the larger twin in addition to the overall risk of prematurity. The clinical course can be affected by elective fetal therapy (‘dichorinization’ of the placenta with laser or selective fetal reduction) or elective delivery in the presence of severe fetal deterioration. The prediction of the clinical outcome in complicated cases of type II and III sFGR cases remains elusive. Novel routines in fetal and placental scans in order to predict neurological impairments and unexpected fetal death to optimize the delivery time-point are needed.
Time-Restricted Feeding Modifies the Fecal Lipidome and the Gut Microbiota

Time-restricted feeding (TRF) has been identified as an approach to reduce the risk of obesity-related metabolic diseases. We hypothesize that TRF triggers a change in nutrient (e.g., dietary fat) absorption due to shortened feeding times, which subsequently alters the fecal microbiome and lipidome. In this report, three groups of C57BL/6 mice were fed either a control diet with ad libitum feeding (16% energy from fat) (CTRL-AL), a high-fat diet (48% energy from fat) with ad libitum feeding (HF-AL), or a high-fat diet with time-restricted feeding (HF-TRF) for 12 weeks. No changes in microbiota at the phylum level were detected, but eight taxonomic families were altered by either feeding timing or dietary fat content. The HF-AL diet doubled the total fecal fatty acid content of the CTRL-AL diet, while the HF-TRF doubled the total fecal fatty acid content of the HF-AL diet. Primary fecal bile acids were unaffected by diet. Total short-chain fatty acids were reduced by HF-AL, but this effect was diminished by HF-TRF. Each diet produced distinct relationships between the relative abundance of taxa and fecal lipids. The anti-obesogenic effects of TRF in HF diets are partly due to the increase in fat excretion in the feces. Furthermore, fat content and feeding timing differentially affect the fecal microbiota and the relationship between the microbiota and fecal lipids.
Changes in functional traits and diversity of typical alpine grasslands after a short-term trampling disturbance

Alpine grassland ecosystem supports high diversity of terrestrial flora and fauna species. Despite the ecological importance and economic potential of this unique ecosystem type, it experiences increasing anthropogenic disturbances such as trampling, which impose negative impact on the health and integrity of alpine grasslands. Previous studies of trampling impact on alpine vegetation mainly focus on changes in vegetation cover and taxonomic diversity after trampling disturbance, but rarely test community-level responses of alpine vegetation to trampling from a functional trait perspective. Through the lens of vegetation functional traits, the present study evaluates the impacts of simulated trampling on typical alpine grasslands in Shangri-la, China. The results showed that although increased trampling intensity did not always lead to changes in functional diversity across all three experimental sites, characteristics of community-weighted mean trait values had consistently changed toward plant species with shorter height, reduced leaf area and lower leaf dry matter content, and such strong shifts in functional attributes may further affect ecosystem goods and services provided by alpine grasslands. Therefore, a functional trait approach can help us better understand the mechanisms that drive trait changes, function shifts and vegetation stability following anthropogenic disturbances.
Symmetry, Regression Design, and Sampling Distributions

When values of regressors are symmetrically disposed, many M-estimators in a wide class of models have a reflection property, namely, that as the signs of the coefficients on regressors are reversed, their estimators' sampling distribution is reflected about the origin. When the coefficients are zero, sign reversal can have no effect. So in this case, the sampling distribution of regression coefficient estimators is symmetric about zero, the estimators are median unbiased and, when moments exist, the estimators are exactly uncorrelated with estimators of other parameters. The result is unusual in that it does not require response variates to have symmetric conditional distributions. It demonstrates the potential importance of covariate design in determining the distributions of estimators, and it is useful in designing and interpreting Monte Carlo experiments. The result is illustrated by a Monte Carlo experiment in which maximum likelihood and symmetrically censored least-squares estimators are calculated for small samples from a censored normal linear regression, Tobit, model.