Miracle-dz/UniFAR-FTUs huggingface dataset:
Homogeneous continua in Euclidean $(n+1)$-space which contain an $n$-cube are $n$-manifolds

Let X be a homogeneous continuum and let En be Euclidean n-space. We prove that if X is properly contained in a connected (n + 1)manifold, then X contains no n-dimensional umbrella (i.e. a set homeomorphic to the set {(xl,., Xn+l) e En+: X12 + xn2+l < I and xn+X < 0 and either x = =n = 0 or Xn+1 = 0}) . Combining this fact with an earlier result of the author we conclude that if X lies in En+l and topologically contains En , then X is an n-manifold. The main purpose of this paper is to prove the following theorem. 1. Theorem. Each homogeneous proper subcontinuum of a connected (n + 1)manifold contains no n-dimensional umbrella. The results of this paper are related to two classical results: the first one of S. Mazurkiewicz [M], and, the second one of R. H. Bing [B]. Namely, with the help of the result of [P], we give a full generalization of the result of [B] to all finite-dimensional cases (Theorem 7 below, and also, the statement formulated in the title). As it was emphasized in [P], the theorem of [B] may be obtained by combining two other theorems: 10 each homogeneous locally connected nondegenerate plane continuum is a simple closed curve (this is the result of [M]), 20 each homogeneous plane continuum that contains an arc is locally connected (this is the step really done in [B]), and thus 30 each homogeneous plane continuum that contains an arc is a simple closed curve. (Bing's proof did not follow this scheme.) One can easily observe that Theorem 1 implies the result of [M] (for n = 1). Thus this paper generalizes step 10. Step 20 has already been extended in [P] to all finite-dimensional cases. Therefore we get Theorem 7 as a generalization of step 30 . Finally, let us stress the fact that, similarly as in [P], the e-push property (Theorem 4) plays a crucial role in the argument of the proof of Theorem 1. Probably, this is the real reason that the results of [P] and of this paper have not been earlier found. Received by the editors June 9, 1987 and, in revised form, June 1, 1988. 1980 Mathematics Subject Classification (1985 Revision). Primary 54F20; Secondary 54C25.
The effects of shadowing on modelling forward radar propagation over a rough sea surface

In order to accurately predict the effects of ocean roughness on forward radar propagation, it is important to incorporate the relevant physical scattering mechanisms. Shadowing is one such mechanism that is particularly important for low-grazing incidence yet it is often not taken into account. One broad class of approximations defines a roughness reduction factor in terms of an ensemble average over surface heights of a Rayleigh phase factor. The widely used Ament approximation and Miller–Brown approximation are two examples from this class of approximations that do not incorporate shadowing. In this paper, we use this class of approximations to develop a ‘shadowed’ approximation that implements a probability density function (PDF) for a rough sea surface illuminated at grazing incidence. A rigorous method of moments calculation is used to compare and quantitatively assess the accuracy of the Ament, Miller–Brown, and shadowed approximations at horizontal polarization. It is shown that the shadowed approximation yields significantly more accurate results than either the Ament or Miller–Brown approximation. In addition, these three approximations are compared with experimental data and it is shown that the shadowed approximation is in good agreement with the data. Finally, numerical curve fitting is used to develop a simple analytical expression for a roughness reduction factor that incorporates shadowing.
Anodal online transcranial direct current stimulation facilitates visual motion perceptual learning

Visual perceptual learning (VPL) has great potential implications for clinical populations, but adequate improvement often takes weeks to months to obtain; therefore, practical applications of VPL are limited. Strategies that enhance visual performance acquisition make great practical sense. Transcranial direct current stimulation (tDCS) could be beneficial to VPL, but thus far, the results are inconsistent. The current study had two objectives: (1) to investigate the effect of anodal tDCS on VPL and (2) to determine whether the timing sequence of anodal tDCS and training influences VPL. Anodal tDCS was applied on the left human middle temporal (hMT+) during training on a coherent motion discrimination task (online), anodal tDCS was also applied before training (offline) and sham tDCS was applied during training (sham). The coherent thresholds were measured without stimulation before, 2 days after and 1 month after training. All participants trained for five consecutive days. Anodal tDCS resulted in more performance improvement when applied during daily training but not when applied before training. Additionally, neither within‐session improvement nor between‐session improvement differed among the online, offline and sham tDCS conditions. These findings contribute to the development of efficient stimulation protocols and a deep understanding of the mechanisms underlying the effect of tDCS on VPL.
Operation features of a longitudinal-capacitive-discharge-pumped CuBr laser

The frequency and energy characteristics of a capacitive-discharge-pumped CuBr laser are investigated. Processes proceeding in the discharge circuit of lasers pumped in this way, in particular, pumped without an external storage capacitor are analysed. It is shown that, depending on the pumping circuit, laser levels are excited either during the charge current flow or during the discharge of electrode capacitances. The differences in the influence of the active HBr addition on the characteristics of the discharge and lasing compared to the case of a usual repetitively pulsed high-current discharge with internal electrodes are established.
Association of the Laminated Vertical Ozone Structure with the Lower-Stratospheric Circulation.

Abstract In this study the examination of the role of the atmospheric circulation in the lower stratosphere in relation to the laminated structure of ozone in the subtropical atmosphere is attempted. This analysis is based on the vertical ozone profile data collected by balloon-borne sondes released at Athens, Greece (38°N, 24°E). From the 29 ozone soundings performed during the winter 1991/92 in the framework of both the European Arctic Stratospheric Ozone Experiment (EASOE) and the Tropospheric Ozone Research (TOR), it is shown that the lamination phenomenon in ozone profiles, especially in the lower stratosphere, was very frequently present. Furthermore, a characteristic minimum of ozone partial pressure at the height region of 1417 km has also been detected. The occurrence of the laminated ozone structure as well as the appearance of the characteristic ozone minimum, correlated with the general circulation, leads to the following results: (a) The laminated ozone profiles are associated with the north.
A Critical Appraisal of the Most Recent Investigations on the Hepatoprotective Action of Brazilian Plants

Conventional treatments for liver diseases are often burdened by side effects caused by chemicals. For minimizing this problem, the search for medicines based on natural products has increased. The objective of this review was to collect data on the potential hepatoprotective activity of plants of the Brazilian native flora. Special attention was given to the modes of extraction, activity indicators, and identification of the active compounds. The databases were Science direct, Pubmed, and Google Academic. Inclusion criteria were: (a) plants native to Brazil; (b) studies carried out during the last 15 years; (c) high-quality research. A fair number of communications met these criteria. Various parts of plants can be used, e.g., fruit peels, seeds, stem barks, and leaves. An outstanding characteristic of the active extracts is that they were mostly obtained from plant parts with low commercial potential, i.e., by-products or bio-residues. The hepatoprotective activities are exerted by constituents such as flavonoids, phenolic acids, vitamin C, phytosterols, and fructose poly- and oligosaccharides. Several Brazilian plants present excellent perspectives for the obtainment of hepatoprotective formulations. Very important is the economical perspective for the rural producers which may eventually increase their revenue by selling increasingly valued raw materials which otherwise would be wasted.
Torsional stability of carbon nanotubes filled with copper atoms

Carbon nanotubes (CNTs) are frequently used as torsional devices in nanoelectromechanical systems; thus it is necessary to gain a thorough understanding of the mechanical behavior of tubes under torsion. In this paper, molecular dynamics simulations are carried out to investigate the torsional buckling of single-walled CNTs completely filled with copper atoms. Results show that, due to metal filling, the torsional rigidity of tubes can be dramatically enhanced and the critical torsional angles of filled tubes can be 2–4 times as high as those of empty ones. Furthermore, due to structural asymmetry in chiral metal-filled tubes, there exists a dependence of the torsional behavior on loading directions. The torsional response of metal-filled tubes is dependent on both tube chirality and loading direction. The microstructure of metal atoms may have a strong influence on the mechanical deformation of metal-filled tubes. These results can provide useful guidelines on the application of CNTs as torsional devices, especially in the case where high torsional stability is required.
Modeling Latent Information in Voting Data with Dirichlet Process Priors

We apply a specialized Bayesian method that helps us deal with the methodological challenge of unobserved heterogeneity among immigrant voters. Our approach is based on generalized linear mixed Dirichlet models (GLMDMs) where random effects are specified semiparametrically using a Dirichlet process mixture prior that has been shown to account for unobserved grouping in the data. Such models are drawn from Bayesian nonparametrics to help overcome objections handling latent effects with strongly informed prior distributions. Using 2009 German voting data of immigrants, we show that for difficult problems of missing key covariates and unexplained heterogeneity this approach provides (1) overall improved model fit, (2) smaller standard errors on average, and (3) less bias from omitted variables. As a result, the GLMDM changed our substantive understanding of the factors affecting immigrants' turnout and vote choice. Once we account for unobserved heterogeneity among immigrant voters, whether a voter belongs to the first immigrant generation or not is much less important than the extant literature suggests. When looking at vote choice, we also found that an immigrant's degree of structural integration does not affect the vote in favor of the CDU/CSU, a party that is traditionally associated with restrictive immigration policy.
Is bitcoin a diversifier, hedge or safe haven for traditional and alternate asset classes?

Abstract Given the skyrocketing returns earned by bitcoin, it has received widespread attention as an investment asset. The shocks experienced by stock and bond markets over time and especially during the COVID-19 pandemic has led to an evaluation of bitcoin as a wealth protection asset, a role that gold has played until now. The current paper tests the hedging and safe haven properties of bitcoin in a broad portfolio of both developed and emerging markets stocks, bonds and real estate over a period of 10 years and during COVID-19 pandemic. Using a DCC-GARCH method, the study finds weak hedge and safe haven benefits of bitcoin. The results of the study establish that there is still a long way to go before bitcoin displays a strong safe haven behavior. However, there is a need for portfolio managers to become more cognizant about bitcoin given its potential to protect their portfolios.
Competing geometric and inertial effects on local flow structure in thick gravity-driven fluid films

The formation and presence of eddies within thick gravity-driven free-surface film flow over a corrugated substrate are considered, with the governing equations solved semianalytically using a complex variable method for Stokes flow and numerically via a full finite element formulation for the more general problem when inertia is significant. The effect of varying geometry (involving changes in the film thickness or the amplitude and wavelength of the substrate) and inertia is explored separately. For Stokes-like flow and varying geometry, excellent agreement is found between prediction and existing flow visualizations and measured eddy center locations associated with the switch from attached to locally detached flow. It is argued that an appropriate measure of the influence of inertia at the substrate is in terms of a local Reynolds number based on the characteristic corrugation length scale. Since, for small local Reynolds numbers, the local flow structure there becomes effectively decoupled from the i.
Forming electrical interconnections through semiconductor wafers

To fabricate electrical interconnections through a semiconductor wafer, an array of holes is laser drilled in the wafer and then a conductor is formed in the holes. Six techniques, including capillary wetting, wedge extrusion, wire insertion, electroless plating, electroforming, and double‐sided sputtering and through‐hole electroplating were used to form conductors in the array of laser‐drilled holes in silicon‐on‐sapphire (SOS) wafers. These techniques are described, and their respective strengths and weaknesses discussed and compared.
COBE Differential Microwave Radiometers - Preliminary systematic error analysis

The Differential Microwave Radiometers (DMR) instrument aboard the Cosmic Background Explorer (COBE) maps the full microwave sky in order to measure the large-angular-scale anisotropy of the cosmic microwave background radiation. Solar system foreground sources, instrumental effects, as well as data recovery and processing, can combine to create statistically significant artifacts in the analyzed data. We discuss the techniques available for the identification and subtraction of these effects from the DMR data and present preliminary limits on their magnitude in the DMR 1 yr maps (Smoot et al. 1992)
Calibration de modèles financiers par minimisation d'entropie relative et modèles avec sauts

Le smile de volatilite implicite observe sur les marches d'options traduit l'insuffisance du modele de Black et Scholes. Avec la necessite d'elaborer un modele d'actif financier plus satisfaisant, vient celle de sa calibration, objet de cette these. La calibration de modeles financiers par minimisation de lentropie relative a ete proposee recemment dans le cadre de la methode de Monte Carlo. On a etudie la convergence et la stabilite de cette methode et on a etendu les resultats a des criteres plus generaux que lentropie relative. La prise en compte des contraintes sur le sous-jacent assurant labsence dopportunite darbitrage a ete abordee sous langle dun probleme de moments. Dans la seconde partie, on a considere un modele simple du phenomene de krach en introduisant en particulier des sauts dans la volatilite du sous-jacent. On a calcule le risque quadratique et effectue un developpement approche du smile utile pour la calibration. Finalement, dans la troisieme partie, on utilise lentropie relative pour calibrer lintensite des sauts dun modele de diffusion avec sauts et volatilite locale. La stabilite de la methode a ete prouvee grâce a des techniques de controle optimal ainsi quau theoreme des fonctions implicites.
The impact of sequential versus simultaneous media exposure on online advertising effectiveness

ABSTRACT Nowadays there is an increasing trend in simultaneous rather than sequential multiple media consumption. At the same time a significant rise in media exposure is recorded, even though the amount of time people spend on media remains constant. The present study examines the effects of sequential versus simultaneous exposure to ads for the same brand on TV and the internet on consumers’ attention to, comprehension of, and attitude toward a banner ad through the mediating effect of cognitive load. An experiment with 291 participants showed that sequential rather than simultaneous media exposure leads to more favorable banner ad attitudes via lower cognitive load, increased attention, and higher subjective comprehension. In sequential media consumption, participants processed the banner ads more systematically and deliberately compared to the simultaneous scenario. Significant implications for the effectiveness of multimedia advertising campaigns are highlighted.
Interpretation of Very High Activation Energies and Frequency Factors in TL as Being Due to Competition Between Centres

Very high values, considered to be physically impossible, were reported for the activation energy E and the frequency factor s in some thermoluminescence (TL) peaks. In particular, peak 5 of LiF:Mg,Ti was reported to have E = 2.0-2.2 eV and s = 10 20 -10 22 s -1 . If a peak shape method or curve fitting of a TL peak is utilised, there is an inverse relation between the width and the activation energy. Thus, if for a given TL peak, competition causes a narrowing of the peak, the effective activation energy is larger than expected. This, in turn, will cause the effective s to be significantly larger than the original one. In this study a model of one trap and three centres is considered, and the relevant simultaneous differential equations solved. Concentrating on the second peak, which looks like a first order peak and is very narrow, results in E = 2.1 eV and s = 8X10 20 s -1 , for original parameter of E = 1.2 eV and s = 2.5 x 10 11 s -1 .
Synthesis and Reactions of 3-Halogenated 2-CF3-Indoles

Halogenation of 2-trifluoromethylindole afforded 3-chloro-, 3-bromo- and 3-iodo derivatives in up to 98% yield. Methyl-, benzyl- and tosyl-groups can be installed at the nitrogen atom of prepared indoles in high yields by base catalyzed reaction with the corresponding alkylating (sulfonylating) reagents. A high synthetic utility of the prepared haloindoles in the reaction with various nucleophilies was shown. The reaction with 4-methylthiophenol and copper cyanide afforded the corresponding sulfides and nitriles in high yield. Palladium catalyzed cross-coupling with phenyl boronic acid and phenylacetylene gave the corresponding 3-phenyl-2-CF3-indoles and acetylenic derivatives in 72–98% yield.
Evaluation of polysomnography findings in children with genetic skeletal disorders

Children with genetic skeletal disorders have variable conditions that can lead to sleep‐disordered breathing, and polysomnography is the gold standard for diagnosing this condition. We aimed to review polysomnography findings, to assess the severity of sleep apnea, and to investigate the clinical variables predictive of sleep‐disordered breathing in these patients. We retrospectively collected the medical records of patients with genetic skeletal disorders who underwent polysomnography for 5 years. Twenty‐seven children with various genetic skeletal disorders, including achondroplasia (14), Crouzon syndrome (3), acromesomelic dysplasia Maroteaux type (3), Apert syndrome (2), osteopetrosis (1), Jeune dysplasia (1), Desbuquois dysplasia (1), acrodysostosis (1), and spondyloepiphyseal dysplasia (1) were enrolled. The median age at the first polysomnography was 58 (1st–3rd quartile: 31–113) months. The overall sleep‐disordered breathing results were: 19 (70.3%) had obstructive sleep apneas (OSA) (4 mild, 6 moderate, 9 severe), 2 (7.4%) had central apneas, 4 (14.8%) had nocturnal hypoventilation. There was a significant correlation between non‐ambulatory status with both total AHI and OSA (p < 0.001, rho: −0.66/p = 0.04, rho: 0.38, respectively). Nine patients received positive airway pressure titration, and the oAHI values of all returned to the normal range. These patients were started with positive airway pressure treatment. Our cohort showed that the majority of the patients with skeletal dysplasia had sleep apnea syndrome characterised mainly by OSA, highlighting the importance of polysomnography screening for sleep disorders. Positive airway pressure therapy represents an effective treatment for sleep‐disordered breathing in those patients.
Sharing Traffic Priorities via Cyber–Physical–Social Intelligence: A Lane-Free Autonomous Intersection Management Method in Metaverse

Replacing traffic signals with roadside vehicle-to-infrastructure systems in the era of connected and autonomous vehicles (CAVs) is promising. Managing CAVs in a signal-free intersection, known as autonomous intersection management (AIM), controls the driving behavior of each intersection-traverse CAV to maximize the throughput. Although AIM improves the gross throughput, the fairness of each individual vehicle in its right of way is not seriously considered. This study sets up an AIM system in the cyber–physical–social space to trade traverse priorities quantitatively and fairly. To that end, one needs an AIM method that is optimal and stable, otherwise no convincing trades of traverse priorities could be made. This study proposes a near-optimal lane-free AIM method based on numerical optimal control, wherein log-exp functions are deployed to convexify nondifferentiable collision-avoidance constraints. Besides that, a parameterized social force model (SFM) is proposed to provide a tunable initial guess for numerical optimal control. By tuning the urgency weights in SFM, one may get cooperative trajectories in different homotopy classes, which are further utilized to decide the amount of virtual currency to reward those CAVs who tend to share their traverse priorities. The overall method improves the traverse throughput with individual fairness respected. In experiencing this system, passengers learn how to behave with politeness when they drive manually. Experiments show the efficiency and robustness of the AIM method and also show the efficacy of the overall priority-sharing system.
Non-Cognitive Factors Affecting Mathematics Performance Using Structural Equation Modeling: Basis for a Mathematics Learning Intervention Framework

The study was conducted to determine the non-cognitive factors affecting the mathematics performance of Bachelor of Secondary Education students using Structural Equation Modeling as a basis for the formulation of a proposed Mathematics Learning Intervention Framework. This study employed a descriptive-correlational method. A total of 266 pre-service teachers participated and answered the survey questionnaires through complete enumeration sampling. The results revealed that self-efficacy, study strategies, teacher support, and involvement directly affect the mathematics performance of the BSED major in mathematics students. In addition to this, the Mathematics Learning Intervention Framework was crafted highlighting self-efficacy, study strategies for math class, teacher support, and involvement factors to improve students' mathematics performance.