Miracle-dz/UniFAR-FTUs huggingface dataset:
A fractional-order model of HIV infection： Numerical solution and comparisons with data of patients

In this paper, a fractional-order model which describes the human immunodeficiency type-1 virus (HIV-1) infection is presented. Numerical solutions are obtained using a generalized Euler method (GEM) to handle the fractional derivatives. The fractional derivatives are described in the Caputo sense. We show that the model established in this paper possesses non-negative solutions. Comparisons between the results of the fractional-order model, the results of the integer model and the measured real data obtained from 10 patients during primary HIV-1 infection are presented. These comparisons show that the results of the fractional-order model give predictions to the plasma virus load of the patients better than those of the integer model.
An optimal test design to evaluate the ability of an examinee by using the stress–strength model

Although the item response theory (IRT) has been widely used to test systems such as the Test of English as a Foreign Language (TOEFL), it is not well known to teachers of mathematics in universities and colleges. The superiority of the IRT over the classical test method is also valid in mathematics in universities and high schools. Since the number of problems in mathematics to be tested in a short time period is strictly limited, particularly in universities, an accurate and efficient method to evaluate the abilities of students is strongly required. In this paper, we propose to use the stress–strength model to estimate the students’ abilities. To perform the optimal test, the up-and-down method by Dixon and Mood [W.J. Dixon and A.M. Mood, A method for obtaining and analyzing sensitivity data, J. Am. Statist. Assoc. 54 (1948), pp. 109–126] is incorporated. Then, the proposed model becomes a generalized test model that includes the stratified adaptive test method by Weiss and the up-and-down method [D.J. Weiss, The stratified adaptive computerized ability test, Research Report 73-3, Psychometric Methods Program, Department of Psychology, University of Minnesota, 1973].
Anisotropic Magnetic Field Dependence of the Zero-Bias Anomaly on In-Plane Oriented [100] Y_{1}Ba_{2}Cu_{3}O_{7-x}/In Tunnel Junctions

Tunneling spectroscopy was performed on in-plane oriented [100] Y1Ba2Cu3O7-x/In tunnel junctions. Splitting of the zero-bias conductance peak at zero magnetic field was observed below 6 K. The splitting increases initially at the rate of 1.3mV/T when the field is applied along the [001] direction, and at a rate of 0.09mV/T and 0.11mV/T when applied parallel to the [010] and [100] directions, respectively. In the [001] direction, at 4.2 K, a sharp transition is seen at a field of about 0.8 T, from a rapid to a slow increase of the splitting. In that orientation, the splitting shows a large magnetic hysteresis.
Dynamics of cascaded resonant radiations in a dispersion-varying optical fiber

Temporal solitons propagating in the vicinity of a zero-dispersion wavelength in an optical fiber emit phase-matched resonant radiations (RRs) as a result of perturbations due to higher-order dispersion effects. These RRs propagate linearly and they usually rapidly spread out in time, thus having a very low peak power. Here, we show that the use of an engineered dispersion-varying optical fiber allows us to induce a completely new dynamics, in which a new physical mechanism—cascade of RRs—is discovered. It is explained by the fact that the RR is temporally recompressed thanks to the change of dispersion sign induced by the varying geometry along the fiber. In addition, we report the experimental evidence of physical processes that had remained unobserved experimentally so far, such as the emission of multiple RRs from a single soliton and the generation of a 500 nm continuum exclusively composed of polychromatic RRs.
Constructing Research Questions: Doing Interesting Research

Research Questions: A Core Ingredient in Developing Interesting Theories The Context of Constructing and Formulating Research Questions Gap-Spotting: The Prevalent Way of Constructing Research Questions in Social Science A Critical Evaluation of Gap-Spotting Research: Does It Lead to Interesting Theories? Problematization as a Methodology for Generating Research Questions Applying the Problematization Methodology in Practice Why Does Gap-Spotting Dominate When It Reduces the Chance to Create Interesting Theories? Constructing Interesting Research Questions: Problematization and Beyond
A matrix method for elastic wave problems

The solution to problems of elastic wave propagation in multilayered media, in which each layer is homogeneous and where the ensemble of layers has physical properties that vary only with one coordinate, may be given as the quotient of products of matrices. In the case of SH waves, the matrices are of order two; in the case of P-SV waves the matrices are of order four. The individual matrix elements are themselves determinants of order two or four in the two cases. The solution is obtained by means of Laplace's development by minors.
Exploring Black Hole Dynamics

This thesis explores the evolution of different types of black holes, and the ways in which black hole dynamics can be used to answer questions about other physical systems. We first investigate the differences in observable gravitational effects between a four-dimensional Randall-Sundrum (RS) braneworld universe compared to a universe without the extra dimension, by considering a black hole solution to the braneworld model that is localized on the brane. When the brane has a negative cosmological constant, then for a certain range of parameters for the black hole, the intersection of the black hole with the brane approximates a Banados-Teitelboim-Zanelli (BTZ) black hole on the brane with corrections that fall off exponentially outside the horizon. We compute the quasinormal modes of the braneworld black hole, and compare them to the known quasinormal modes of the three-dimensional BTZ black hole. We find that there are two distinct regions for the braneworld black hole solutions that are reflected in the dependence of the quasinormal modes on the black hole mass. The imaginary parts ωI of the quasinormal modes display phenomenological similarities to the quasinormal modes of the three-dimensional BTZ black hole, indicating that nonlinear gravitational effects may not be enough to distinguish between a lower-dimensional theory and a theory derived from a higher-dimensional braneworld. Secondly, we consider the evolution of non-extremal black holes in N = 2, d = 4 supergravity, and investigate how such black holes might evolve over time if perturbed away from extremality. We study this problem in the probe limit by finding tunneling amplitudes for a Dirac field in a single-centered background, which gives the decay rates for the emission of charged probe black holes from the central black hole. We find that there is no minimum to the potential for the probe particles at a finite distance from the central black hole, so any probes that are emitted escape to infinity. If the central black hole is BPS in the extremal limit, then the potential is flat and so there is no barrier to the emission of probes. If the central black hole is non-BPS in the extremal limit, then there is a barrier to emission and we compute the decay rate, which depends both on the charge of the central black hole and the charges of the emitted black holes. Finally, we consider the possibility that an extremal black hole, the end-point of the evolution of a non-extremal black hole through evaporation, may itself split into a multi-centered black hole solution through quantum tunneling, via a gravitational instanton analogous to the instanton for the symmetric double well in elementary quantum mechanics. We find a gravitational instanton that connects two vacuum states: one state corresponding to a single-centered extremal Reissner-Nordstrom (ERN) black hole configuration, and another state corresponding to a multi-centered ERN configuration. We evaluate the Euclidean action for this instanton and find that the amplitude for the tunneling process is equal to half the difference in entropy between the initial and final configurations.
Emergence of cooperation, network formation and selection of interactions

We propose a model of emergence of cooperation in evolutionary games that high- lights the role of network formation and effect of network structure. In line with empirical data, the model proposes a mechanism that explains the persistence of heterogeneous types (heterogeneity in rules for changing behavior) within a population, and in particular the sustainability of altruism (presence of unconditional cooperators) even in case of strong social dilemma. This explanation constitutes an alternative to the choice and refusal mechanism that is often presented as an explanation for cooperation on dynamic networks. We also exhibit a minimal set of strategies for emergence of cooperation (altruists, reciprocators and selfish agents) and sketch a two steps scenario for this emergence. We adopt an hybrid methodology with both analytical and computational insights.
Resonance-frequency based electrical impedance spectroscopy and its detection sensitivity to breast lesions

Electrical impedance spectroscopy (EIS) has been investigated and emerged as a potential non-invasive, low cost, and convenient tool for prescreening and detecting breast abnormalities that could lead to developing breast cancers. However, the performance of conventional EIS is unacceptable in clinical practice. In our laboratory, we developed a new EIS approach based on resonance frequency measurements. This system relies on parameters generated by resonating breast capacitance with a fixed inductor in six different directions using the nipple as a reference electrode. The system detects breast tissue abnormalities due to capacitance changes caused by angiogenesis. Although preliminary testing results from a prospective clinical study were encouraging, we found that detection results were not robust. One of the primary reasons is that the measured EIS signals, in particular, resonance frequencies vary with lesion-depth. Using circuit theory we investigated and derived analytical expressions between the sensitivity of capacitance changes and parallel resistances to pathologies with respect to distances of the lesions from the nipple electrode. The resistance shorts the measured EIS signal thereby decreasing amplitudes of waveforms at resonance frequency. The theoretical analysis is consistent with our experimental observation, which provides valuable data and guidelines for us to develop and construct a new resonance-frequency based EIS system using a lumped parameter (resistance and multi-layer capacitance) based breast model, resulting in an optimal electrical circuit for future studies.
A P HYLOGENETIC S TUDY OF THE C ONCEPT OF C ELESTIAL O RB M

This paper presents a phylogenetic study of the concept of orb from its rise to its abandonment. While a heavy load of literature is dedicated to the introduction and abandonment of the concept, there are few systematic studies on the semantic components of this concept in the Islamic tradition of astronomy. We will investigate conceptual articulation among Arab astronomers by distinguishing the astronomical and philosophical understandings of the concept. While the former mainly focuses on the empirical evidence, the latter emphasizes causal and physical role of the concept’s referent. Such a distinction enables us to characterize some key conceptual components of the concept of orb. Among other components articulated by the Arab astronomers, the hardness of orbs, led Tycho Brahe and his fellow astronomers to abandon the concept.
Multilayer configuration for experiments of spin precession induced by a dc current

Until now, most predictions about spin precession induced by a CPP dc current have concerned a simple “asymmetric” configuration consisting of a free magnetic layer and of a thicker pinned magnetic layer. In the present work, we propose a different configuration where the precessing free magnetic layer is sandwiched between two thicker pinned magnetic layers having opposite magnetizations. In this “antisymmetric” configuration, the spin current and accumulation arising from expansion/contraction are nearly three times as large as in the asymmetric configuration, for given current and layer thickness. Moreover, both interfaces of the free magnetic layer are now active to generate drive torques. This should result in a reduction of the critical current density needed for spin oscillations, by a factor of about six.
Coupling of gas chromatography and molecular beam/mass spectrometry analytical techniques: Application to flame structure study

A new experimental technique coupling both molecular beam and mass spectrometry (MBMS) and gas chromatography (GC) is developed to improve the analysis of low pressure reactive systems using a probe sampling procedure. The sensitivity of gas chromatography is greatly enhanced by using a compression procedure for the samples before injection into the chromatograph, and its selectivity allows one to separate isomers and to study very complex mixtures. By contrast MBMS is well suited to atoms and radical species detection. Moreover, the temperature dependence of the fragmentation pattern of heavy hydrocarbons during MBMS ionization is pointed out and it can be resolved alternatively by GC calibration. The complementarity of these two analytical techniques is demonstrated in the case of low pressure natural gas flames study.
Orders of accumulation of entropy and random subshifts of finite type

Title of dissertation: ORDERS OF ACCUMULATION OF ENTROPY AND RANDOM SUBSHIFTS OF FINITE TYPE Kevin McGoff, Doctor of Philosophy, 2011 Dissertation directed by: Professor Mike Boyle Department of Mathematics The first portion of this dissertation concerns orders of accumulation of entropy. For a continuous map T of a compact metrizable space X with finite topological entropy, the order of accumulation of entropy of T is a countable ordinal that arises in the context of entropy structure and symbolic extensions. We show that every countable ordinal is realized as the order of accumulation of some dynamical system. Our proof relies on the functional analysis of metrizable Choquet simplices and a realization theorem of Downarowicz and Serafin. Further, ifM is a metrizable Choquet simplex, we bound the ordinals that appear as the order of accumulation of entropy of a dynamical system whose simplex of invariant measures is affinely homeomorphic to M . These bounds are given in terms of the Cantor-Bendixson rank of ex(M), the closure of the extreme points of M , and the relative CantorBendixson rank of ex(M) with respect to ex(M). We also address the optimality of these bounds. Given any compact manifoldM and any countable ordinal α, we also construct a continuous, surjective self-map of M having order of accumulation of entropy α. If the dimension of M is at least 2, then the map can be chosen to be a homeomorphism. The realization theorem of Downarowicz and Serafin produces dynamical systems on the Cantor set; by contrast, our constructions work on any manifold and provide a more direct dynamical method of obtaining systems with prescribed entropy properties. Next we consider random subshifts of finite type. Let X be an irreducible shift of finite type (SFT) of positive entropy, and let Bn(X) be its set of words of length n. Define a random subset ω of Bn(X) by independently choosing each word from Bn(X) with some probability α. Let Xω be the (random) SFT built from the set ω. For each 0 ≤ α ≤ 1 and n tending to infinity, we compute the limit of the likelihood that Xω is empty, as well as the limiting distribution of entropy for Xω. For α near 1 and n tending to infinity, we show that the likelihood that Xω contains a unique irreducible component of positive entropy converges exponentially to 1. These results are obtained by studying certain sequences of random directed graphs. This version of “random SFT” differs significantly from a previous notion by the same name, which has appeared in the context of random dynamical systems and bundled dynamical systems. ORDERS OF ACCUMULATION OF ENTROPY AND RANDOM SUBSHIFTS OF FINITE TYPE
Efficiency droop in InGaN/GaN blue light-emitting diodes: Physical mechanisms and remedies

Physical mechanisms causing the efficiency droop in InGaN/GaN blue light-emitting diodes and remedies proposed for droop mitigation are classified and reviewed. Droop mechanisms taken into consideration are Auger recombination, reduced active volume effects, carrier delocalization, and carrier leakage. The latter can in turn be promoted by polarization charges, inefficient hole injection, asymmetry between electron and hole densities and transport properties, lateral current crowding, quantum-well overfly by ballistic electrons, defect-related tunneling, and saturation of radiative recombination. Reviewed droop remedies include increasing the thickness or number of the quantum wells, improving the lateral current uniformity, engineering the quantum barriers (including multi-layer and graded quantum barriers), using insertion or injection layers, engineering the electron-blocking layer (EBL) (including InAlN, graded, polarization-doped, and superlattice EBL), exploiting reversed polarization (by either inv.
Linear polarization of astronomical masers and magnetic fields

The ability of magnetic fields to cause high linear polarization in the radiation emitted by astronomical masers is examined. Because substantial linear polarization is a common feature of the circumstellar SiO masers and because their emitted power indicates masing under saturated conditions, the constraints provided by the SiO masers in late-type giants are emphasized.
Using smartphone-GPS data to quantify human activity in green spaces

Cities are growing in density and coverage globally, increasing the value of green spaces for human health and well-being. Understanding the interactions between people and green spaces is also critical for biological conservation and sustainable development. However, quantifying green space use is particularly challenging. We used an activity index of anonymized GPS data from smart devices provided by Mapbox (www.mapbox.com) to characterize human activity in green spaces in the Greater Toronto Area, Canada. The goals of our study were to describe i) a methodological example of how anonymized GPS data could be used for human-nature research and ii) associations between park features and human activity. We describe some of the challenges and solutions with using this activity index, especially in the context of green spaces and biodiversity monitoring. We found the activity index was strongly correlated with visitation records (i.e., park reservations) and that these data are useful to identify high or low-usage areas within green spaces. Parks with a more extensive trail network typically experienced higher visitation rates and a substantial proportion of activity remained on trails. We identified certain land covers that were more frequently associated with human presence, such as rock formations, and find a relationship between human activity and tree composition. Our study demonstrates that anonymized GPS data from smart devices are a powerful tool for spatially quantifying human activity in green spaces. These could help to minimize trade-offs in the management of green spaces for human use and biological conservation will continue to be a significant challenge over the coming decades because of accelerating urbanization coupled with population growth. Importantly, we include a series of recommendations when using activity indexes for managing green spaces that can assist with biomonitoring and supporting sustainable human use.
Productivity and Efficiency of a Department Resident Aesthetic Plastic Surgery Clinic

Abstract Background There has been increasing demand for aesthetic surgery procedures in the United States, highlighting the critical importance of the competence of plastic surgery residents and rigorous methods of aesthetic surgery training. Objectives The objective of this study was to review procedures and outcomes from our plastic surgery resident aesthetic clinic. Outcomes and costs were compared to national averages and reports from the literature. Methods A retrospective chart review identified all adult patients who presented to the Resident Aesthetic Surgery Clinic at NYU Langone Health in 2021. Patient demographics, comorbidities, procedural data, postoperative complications, revisions, and surgeon fees were compiled. A brief confidence survey was distributed to participating residents before and after their clinic rotation. Data were analyzed using IBM SPSS software (Armonk, NY). Results In 2021, 144/379 consultations led to an operation (38.0% conversion rate), resulting in 420 distinct surgical procedures. The majority (53.3%) of procedures involved the head and neck. Complication and revision rates were 5.5% and 1.0%, respectively, with surgeon fees consistently below the national average. Residents reported being significantly more confident performing face lifts, rhinoplasties, and aesthetic surgery in general following their clinic rotation. Conclusions These data represent the largest annual reported study of plastic surgery resident aesthetic procedures and outcomes, demonstrating the high volume and productivity of the NYU Resident Aesthetic Surgery Clinic. These results further support resident aesthetic clinics as a robust training modality. Level of Evidence: 4
Special Collection: World-Scale Ecology and Management of Fall Armyworm (Spodoptera frugiperda) What Defines a Host? Oviposition Behavior and Larval Performance of Spodoptera frugiperda (Lepidoptera: Noctuidae) on Five Putative Host Plants

When an invasive species first breaches quarantine and establishes in yet another country, it invariably causes consternation for growers, in part because of incomplete understanding of the plants that are at risk. The Fall Armyworm, Spodoptera frugiperda (J.E. Smith) is the most recent example in Australia. The number of plants that this polyphagous noctuid is reported to attack is vast, including many crop species. Consequently, initial reactions from grower industry groups that perceived themselves at risk were to demand emergency use of insecticides. Yet the field evidence suggests that many crops might not be at risk and since S. frugiperda arrived in Australia, maize crops have suffered most damage, followed by sorghum. We question the accuracy of some of the claims of reported host plants of S. frugiperda and report experiments that compared oviposition behavior, neonate silking behavior, and larval performance on five crops: the known hosts maize and sorghum, and the putative hosts cotton, peanut, and pigeon pea. Maize ranked highest in all preference and performance measures, followed by sorghum and peanut, with pigeon pea and cotton ranking lowest. Although S. frugiperda can survive, develop, and pupate on the crop species we examined, cotton and pigeon pea are not preferred by the pest in either the larval or adult stages. We suggest that before a plant is listed as a host for a given insect that the evidence should be fully reported and carefully evaluated. Collecting an immature insect from a plant does not make that plant a host!