Miracle-dz/UniFAR-FTUs huggingface dataset:
Nonalcoholic steatohepatitis: An emerging cause of cirrhosis in Colombia

Introduction: Cirrhosis of the liver is a significant cause of morbidity and mortality in Latin America; the increased prevalence of metabolic syndrome in our population could be chan - ging the epidemiological profile of patients with advanced chronic liver disease. Aim: To characterize a group of patients with cirrhosis of the liver at an outpatient hepatology care center in Cartagena de Indias, Colombia, and determine the contribution of nonalcoholic steatohepatitis (NASH) as an etiological factor in this population. Materials and methods: Retrospective, cross-sectional, analytical study. All patients who attended the hepatology fo - llow-up with a diagnosis of cirrhosis of the liver were in the six-monthly follow-up protocol that included screening for hepatocellular carcinoma (HCC) and esophageal varices. Results: 346 patients were included, most were women (54.3 %). The first and second causes of cirrhosis were cryptogenic (35 %) and NASH (30.9 %), respectively, followed by viral hepatitis (17 %) and autoimmune diseases (9 %). Of these patients, 87.4 % were within categories A and B of the Child-Turcotte-Pugh score, and only 12.5 % (33 patients) were in stage C. Also, 60 % had at least one clinical decompensation, 38 % a history of variceal hemorrhage, and 4 % a diagnosis of HCC; 80.6 % of patients with NASH cirrhosis had diabetes, and 46.7 % were overweight. Conclusion: NASH cirrhosis is an emerging cause of advanced chronic liver disease in Colombia.
A constitutive model for cracking of concrete based on the incremental theory of plasticity

A constitutive model based on classical plasticity theory for non‐linear analysis of concrete structures using finite elements is presented. The model uses the typical parameters of non‐associated plasticity theory for frictional materials and a modified Mohr‐Coulomb yield surface is suggested. Onset and amount of cracking at a point are controlled by the values of the effective plastic strain and thus it can be studied by a posteriori postprocessing of numerical results. The accuracy and objectivity of the model is checked out with some examples of application.
Energy level statistics in the transition region between integrability and chaos

A generic one-parameter family of billiards discovered and introduced by Robnik (1983) is used to study the spectral properties of corresponding quantum systems. When the parameter is varied a smooth transition from an integrable system over a typical KAM system to an almost ergodic system can be observed. The authors calculate up to 7600 lowest reliable energy levels. A detailed analysis of the numerical data shows significant deviation from the semiclassical Berry-Robnik formulae for the nearest-neighbour level spacing distribution P(S) except for large level spacings, S>1, which can only be explained by a very slow convergence towards the semiclassical regime where these formulae are predicted to be correct. At small S the power-law level repulsion is clearly observed and a fit by the phenomenological formula by Izrailev (1988,1989) is statistically significant.
Mathematics, Science of Possibility ‐‐ A Critical Review

Summary This paper supports the view that search for the applicative standpoint in mathematical education has yet to be sufficiently exploited. Mathematical propositions are considered to have both an ‘internal’ and ‘external’ role and thus a system of ‘potential models’ is evolved. Despite the stress on the applicative nature of the subject it is argued in conclusion that the position in the body of the paper is compatible with the synthetic apriority of mathematics. * C. P. Ormell, ‘Mathematics, science of possibility’, Int. J. Math. Educ. Sci. Technol. 3, 329‐341 (1972).
QED theory for excitons with microscopic nonlocality

We have constructed QED theory for excitons with microscopic nonlocality or nonlocal susceptibility originating from their center-of-mass motion. The nonlocality must be properly considered in excitons' weak (center-of-mass) confinement regime where the long wavelength approximation is breakdown. This theory keeps good correspondences with its underlying theories, the QED theory for dispersive and absorptive local dielectrics and the microscopic nonlocal theory developed in the semi-classical framework. Our theory provides correlation functions of excitons, which renormalize radiative shift, transition between exciton states via electromagnetic fields, radiative and nonradiative relaxation processes. By using these functions, we can systematically study various nonlinear, dephasing, and emission processes of excitons in weak-confinement to bulk-like systems.
Hubble constant, lensing, and time delay in Te Ve S

Abstract The Hubble constant can be determined from the time delay of gravitationally lensed systems. We adopt Te Ve S as the relativistic version of Modified Newtonian Dynamics to study gravitational lensing phenomena and evaluate the Hubble constant from the derived time-delay formula. We test our method on observed quasar lensing published in the literature. Three candidates are suitable for our study, HE 2149-2745, FBQ J0951+2635, and SBS 0909+532.
Applicability of a Stochastic Model to Nonlinear Shoaling of Surface Waves

This paper examines the applicability of a stochastic model for the propagation of random waves in shallow water including triad near-resonance interactions. The model is derived from evolution equations for complex Fourier amplitudes of fully dispersive multidirectional waves. The closure used in the stochastic equations is adopted from the theory of weak turbulence based on the assumption of quasi-normal sea state. In the model formulation, the second- and third-order wave statistics are formulated by evolution equations for the wave energy spectrum and bispectrum. These equations are implemented numerically, for the case of unidirectional waves, to compute the evolution of the wave energy spectrum and the bispectrum. Experimental measurements for random wave transformation over a shoal (submerged bar) are compared against the numerical-model results. The stochastic model accurately predicted the wave spectra and third-order statistics, in regions where the Ursell number is smaller than 1.5. For larger Ursell-number values, the stochastic model tends to over-estimate the content of high-frequency energy, and the skewness and asymmetry, compared to its deterministic counterpart.
Dual-wavelength distributed feedback laser for the generation of terahertz radiation

The use of terahertz radiation bears great potential for various applications. We propose a method for obtaining terahertz radiation based on frequency difference generation from two-longitudinal-mode emission of monolithic distributed feedback lasers with modulated gratings. The frequency separation of the two dominating longitudinal modes of the proposed device structure can cover a wide range and several structural and operation point parameters can be used for coarse- and fine-tuning. Moreover, the nearly perfect overlapping of the dominant modes' optical field transverse distributions is enabling high-efficiency terahertz generation. The paper presents design formulas, simulation results and discusses the influences of the fabrication inaccuracies on the target frequency separation.
Independent Two-Fields Solution for Full-Potential Unsteady Transonic Flows

The paper introduces a new approach for the numerical solution of full-potential unsteady flows based on an independent approximation of the density and velocity potential fields. The solution procedure relies on an unstructured, node-based, finite volume approximation, with linear shape functions and nonreflecting farfield boundary conditions. An improved upwind density biasing allows us to stabilize the solution in supersonic regions. In view of linearized aeroelastic stability and response analyses, unsteady boundary conditions are accounted for by means of a density flow transpiration. Time marching solutions are dealt using first/second-order implicit schemes, whose unconditional linearized stability properties are demonstrated. A few applications are presented to validate the method.
Trapping and sedimentation of inertial particles in three-dimensional flows in a cylindrical container with exactly counter-rotating lids

Stirring and sedimentation of solid inertial particles in low-Reynolds-number flows has acquired great relevance in multiple environmental, industrial and microfluidic systems, but few detailed numerical studies have focused on chaotically advected experimentally realizable flows. We carry out one-way coupling simulations to study the dynamics of inertial particles in the steady three-dimensional flow in a cylindrical container with exactly counter-rotating lids, which was recently studied by Lackey & Sotiropoulos (Phys. Fluids, vol. 18, 2006, paper no. 053601). We elucidate the rich Lagrangian dynamics of the flow in the vicinity of toroidal invariant regions and show that depending on the Stokes number inertial particles could get trapped for long times in different equilibrium positions inside integrable islands. In the chaotically advected region of the flow the balance between inertia and gravity forces (represented by the settling velocity) can produce a striking fractal sedimentation regime, characterized by a sequence of discrete deposition events of seemingly random number of particles separated by hiatuses of random duration. The resulting staircase-like distribution of the time series of the number of particles in suspension is shown to be a devil's staircase whose fractal dimension is equal to the 0.87 value found in multiple dissipative dynamical systems in nature. Our work sheds new light on the complex mechanisms governing the stirring and deposition of inertial particles and provides new information about the parameters that are relevant in the characterization of particle dynamics in different regions of chaotically advected flows.
Logic-Based Methods for Optimization: Combining Optimization and Constraint Satisfaction

Some Examples The Logic of Propositions The Logic of Discrete Variables The Logic of 0-1 Inequalities Cardinality Clauses Classical Boolean Methods Logic-Based Modeling Logic-Based Branch and Bound Constraint Generation Domain Reduction Constraint Programming Continuous Relaxations Decomposition Methods Branching Rules Relaxation Duality Inference Duality Search Strategies Logic-Based Benders Decomposition Nonserial Dynamic Programming Discrete Relaxations References Index.
Oscillations of a Gas Bubble in Viscoelastic Liquids Subject to Acoustic and Impulsive Pressure Variations

An analysis is presented of the forced oscillations of a gas‐filled bubble at rest in a large body of a linear viscoelastic fluid. Two types of forcing are considered. In the first, oscillations are induced by a pressure surge on the system. For the three‐parameter fluid model employed, numerical computations show that for a given ratio of the fluid's elastic modulus to the pressure surge, the damping of the bubble motion exhibits a maximum as a function of the fluid relaxation time at a value of this parameter equal approximately to one‐fifth the natural period of oscillation. At very high or very low relaxation times, the damping becomes insignificant. As the second type of forced oscillation, we consider the motion induced by the application of ultrasonic waves to the system. Here, damping is found to depend strongly on the product of impressed frequency and fluid relaxation time.
Temperature–Velocity Coupling of the Convective Heat Transfer Sensitivity Analysis

ABSTRACT This article deals with sensitivity studies of the temperature–velocity coupling of convective heat transfer problems with laminar fluid flow. Sensitivity coefficients contain information about the chances of a successful inverse procedure, and they can be used in a number of inverse schemes, i.e., the Levenberg-Marquardt method. Special emphasis is given in this article to the numerical solution of the direct problem, which was obtained by the control-volume finite-element method formulation. This numerical tool was used for the sensitivity coefficients evaluation and can be used for simulation of real measurements in the full inverse algorithm. The algorithm for the sensitivity coefficients evaluation and example distributions of the sensitivity coefficients are given. A proposed full inverse procedure, allowing determination of inflow velocity based on internal temperature measurements, is also included. The inverse method employs the Levenberg-Marquardt method for stabilization purposes.
Evaluation of Artemia sp. (Branchiopoda, Artemiidae) as an alternative prey for laboratory rearing of Tupiocoris cucurbitaceus (Hemiptera: Miridae), a predator of horticultural pests

Tupiocoris cucurbitaceus (Spinola) (Hemiptera: Miridae) is a predator of whiteflies (Hemiptera: Aleyrodidae) present in several American countries. Rearing this bug requires the use of plants as ovipositional substrate and a prey to feed on to complete its development. Artemia sp. (Branchiopoda, Artemiidae) cyst, a crustacean tested for the laboratory rearing of other hemipteran species, could be used as food, being less expensive than the species commonly employed (Sitotroga cerealella [Olivier] [Lepidoptera: Gelechiidae]). The objective of the present study was to determine nymphal developmental time, nymphal mortality, fertility, and sex ratio of T. cucurbitaceus fed on Artemia sp. cysts. Three diets were used during the rearing of three generations: S. cerealella eggs, Artemia sp. cysts and a mix of both species. The nymphal developmental time (11 to 13 days), nymphal mortality (40 to 66 %), and adult fertility (74 to 101 nymphs / female) were similar for all diets. In all cases, the adults showed a high female proportion (0.67-0.97). In conclusion, Artemia sp. cysts are suitable for T. cucurbitaceus laboratory rearing at least for three generations.
Imaging and characterization of activated CO2 species on Ni(110)

By means of a joint experimental and theoretical approach we provide single molecule imaging and characterization of CO2 on Ni(110), chemisorbed with high charge transfer from the substrate in an activated state that plays a crucial role in the hydrogenation process. Low-temperature scanning tunneling microscopy images of single CO2 molecules are combined with ab initio density-functional-theory calculations, where dispersive forces and zero-point energy estimates have been explicitly accounted for. We obtain a detailed characterization of the adsorption geometries and an estimate of the energies corresponding to the different adsorbed states. A consistent picture of CO2 chemisorption on Ni(110) is provided on the basis of the newly available information, yielding a deeper insight into the previously existing spectroscopic and theoretical data.
Coordinated observations of the quiet Sun transition region using SUMER spectra, TRACE images and MDI magnetograms

The relationship between the transition region ultraviolet emission and the underlying magnetic eld is explored through a detailed analysis of SUMER Si iv line proles, TRACE C iv, continuum and 171 A intensities, and MDI high resolution magnetic eld measurements. The observations track a narrow area of quiet Sun near disk center over a period of 3 hours. Highly variable emission is found throughout. The most dramatic line Doppler shift and brightness variations come from a region of complex eld evolution. The brightenings sometimes have faint elongated extensions in the TRACE C iv images. In most events with high Doppler shifts, the Si iv line wing reveals plasma flow 1{2 min before the line core brightens which suggests that plasma acceleration precedes plasma compression and/or heating. Simultaneous measurement of transition region densities using O iv line ratios imply large density fluctuations in the transition region plasma. There is an indication of waves of compression and rarefaction crossing the spectrometer's eld-of-view. The waves' speed across the solar surface is between 20{40 km s 1 , and the compression may be as high as 10. In space-time images density fluctuations are much more prevalent and conspicuous than brightenings. In several cases the waves seem to start at the position of Si iv brightenings.
Passive fiber ring as a device for effective refractive index measurement

Fiber optic rings are used for synchronization of modes and optical pulses shaping in fiber lasers. The resulting pulses are characterized by stable amplitude and reduced chirp. The length of fiber ring is chosen so as to avoid loss of laser light coherence. New application of optical fiber loops is their inclusion in the closed loop during their excitation by laser light modulated by low-frequency signal and middle frequency signal. If loop also includes amplifying fiber which covers losses incurred by couplers will thus be possible evaluated a signal delay in long loop and thus measure the length of fiber. Reverse task is possibility to measure n1eff if we know the length of SM fiber loop. This type of designed fiber optic oscillator consists of single-mode optical fiber SM28e in lengths of order of kilometers. This fiber is connected in a series with erbium doped fiber that covers loop losses. Loop, which acts as an oscillator is excited by DFB lasers both at a wavelength of 1550 nm and at wavelength of 1310 nm. The paper will demonstrated the comparison between active and passive fiber loops and their influence to accuracy of effective refractive index measurement.
Research on Information Process with a Computational Approach to Some Odd-Graceful Trees

Graph labeling theory has important applications in coding theory, communication networks, logistics and other aspects. In Operations Research or Systems Engineering Theory and Methods, one very often use graph colorings/labellings to divide large systems into subsystems. One can use colorings/labellings to distinguish vertices and edges between vertices in order to find fast algorithms to imitate some effective transmissions and communications in information networks. In this paper we present a computational approach to the odd-graceful labelings for some olive trees.
3-D synthetic aperture processing on high-frequency wide-beam microwave systems

The use of High-Frequency MicroWaves (HFMW) for high-resolution imagery has gained interest over the last years. Very promising in-depth applications can be foreseen for composite non-metal, non-polarized materials, widely used in the aeronautic and aerospace industries. Most of these materials present a high transparency in the HFMW range and, therefore, defects, delaminations or occlusions within the material can be located. This property can be exploited by applying 3-D HFMW imaging where conventional focused imaging systems are typically used but a different approach such as Synthetic Aperture (SA) radar can be addressed. This paper will present an end-to-end 3-D imagery system for short-range, non-destructive testing based on a frequency-modulated continuous-wave HFMWsensor operating at 100 GHz, implying no health concerns to the human body as well as relatively low cost and limited power requirements. The sensor scans the material while moving sequentially in every elevation plane following a 2-D grid and uses a significantly wide beam antenna for data acquisition, in contrast to focused systems. Collected data must be coherently combined using a SA algorithm to form focused images. Range-independent, synthetically improved cross-range resolutions are remarkable added values of SA processing. Such algorithms can be found in the literature and operate in the time or frequency domains, being the former computationally impractical and the latter the best option for in-depth 3-D imaging. A balanced trade-off between performance and image focusing quality is investigated for several SA algorithms.
Operational performance of the TIMED Doppler Interferometer (TIDI)

The TIMED Doppler Interferometer (TIDI) is a Fabry-Perot interferometer designed to measure winds in the mesosphere and thermosphere (60-180 km) as part of the TIMED mission. TIDI is a limb viewer and observes emissions from OI 557.7 nm and rotational lines in the O2(0-0) Atmospheric band. Wind measurement accuracies approach 3 ms-1 in the mesosphere and 15 ms-1 in the thermosphere. The TIDI instrument’s performance during the first year and a half of operation is discussed in this paper. Many subsystems are working as designed. The thermal control system is holding the instrument temperatures at their desired set-points. The CCD detector is working as expected with no changes observed in the gain, bias or read noise. The instrument suffers from a light leak that causes the background to be elevated and increases the uncertainty in the wind measurement. Nothing can be done to eliminate this problem but modeling of the background has eliminated any systematic effect. Water outgassing from the spacecraft or instrument has deposited as ice on some part of the optics and reduced the instrument’s sensitivity. This problem has been reduced by two spacecraft rolls which pointed the TIDI radiator to view more of the earth causing the optics to warm up and sublimate much of the ice.
Algebraic deformations and triple cohomology

The fundamental theorems of algebraic deformation theory are shown to hold in the context of enriched triple cohomology. This unifies and generalizes the classical theory. The fundamental results in algebraic deformation theory connect the low order cohomology groups of an algebra A with the existence of deformations of the algebra structure on A. The theory for associative algebras was initiated by Gerstenhaber in [6], where he also outlined techniques applicable to other special cases (see [7]). Here we give a unified treatment of the deformation theories for a broad class of algebra types using the enrichment over the category of coalgebras and triple cohomology (see [1] and [2]). Let R be a commutative ring and let (T, ,u, q) be a triple on the category Mod-R. Recall that a T-algebra structure on an R-module A is given by a map a: A T -* A satisfying the equations: (a)Ta =u -a:AT2--. A, a7 a=id:A -A. (1) Following Gerstenhaber, we would like to investigate when a formal power series a + >2a,x with coefficients in HomR(AT, A) determines a formal T-algebra structure on A (or a T-algebra structure on A [[x]J, see [6]). Direct use of the conditions (1) immediately brings up the problem of the nonadditivity of most triples of interest, e.g. the tensor-algebra triple. To circumvent this problem we must use an additive enrichment of T over the category of R-coalgebras. We shall assume that the algebras for T are definable by a set of finitary multilinear operations (see [1] or [5]) which is the case for most categories of interest, e.g. associative algebras, commutative algebras, Lie algebras, etc. Coalgebras and enrichments. Recall that an R-coalgebra (C, 8, e) is an R-module C equipped with maps 3: C -* C C) C and e: C -* R satisfying the equations 8 (id ? 3) 3 8 (3 0 id), 8 (id 0 e) id 3 8 (e 0 id), and 83 -T = 8 where T is the "twist" isomorphism C 0 C -C 0 C, and the other isomorphisms are the obvious canonical ones. The category of all R-coalgebras and their structure preserving maps will be denoted Coalg. This is cartesian closed and serves as a base category over which most categories of R-algebras are enriched (see [1] or [5]). Received by the editors June 1, 1977 and, in revised form, October 4, 1978. AMS (MOS) subject classifications (1970). Primary 16A58, 18C15, 18D15. 'The author wishes to thank the Forschungsinstitut fur Mathematik of the ETH for their hospitality, and Jon Beck and Michael Barr for suggesting that this work could be done. i 1980 American Mathematical Society 0002-9939/80/0000-01 52/$02.50