Miracle-dz/UniFAR-FTUs huggingface dataset:
Regions where transient signals are influenced between a source and receiver

At infinite frequency, the only place that a medium can influence the waveform of a received signal that is emitted from a source is along one or more infinitesimally thin ray paths. For any transient signal at finite frequencies, an exact method is developed to compute the regions in a medium that significantly influence the received signal for any specified window of signal travel time. This window is sometimes chosen to surround a peak. Results at finite frequencies differ from those at infinite frequency because of diffraction. The method has its foundation in the integral theorem of Helmholtz and Kirchhoff. Part of the method involves a filter that yields an imperfect but apparently useful picture of influential regions in the presence of interfering waves. The method is useful for quantifying differences between the region of influence and a ray, and for identifying regions in which medium fluctuations significantly influence signal aberrations at a receiver. Four principal results are found at low frequencies. They are: 1) For propagation in homogeneous media, a significant portion of the received signal is influenced by waves that traverse paths that are approximately integer and half-integer numbers of cycles greater than the straight path between source and receiver. Such paths are called ‘constructive and destructive paths of influence’, respectively. They correspond to edge-diffracted rays for the geometrical theory of diffraction. 2) For reflection from a flat interface in an otherwise homogeneous medium, the received signal is significantly influenced by constructive and destructive paths of influence whose angles of incidence and reflection differ (non-specular reflection). 3) For acoustic propagation centered at 100 Hz in an oceanic acoustic waveguide, the region of influence markedly departs from a ray path, particularly near the reflective ocean surface. The influential region is flat for O(10) km instead of O(1) km for a ray. 4) The first Fresnel zone is an inappropriate scale to characterize the region of influence for transient signals near a steep ray in inhomogeneous media, as assumed by at least one scattering theory. Modification of that theory may yield a better fit with data.
A hybrid nudging‐ensemble Kalman filter approach to data assimilation in WRF/DART

A hybrid nudging‐ensemble Kalman filter (HNEnKF), previously tested in the Lorenz three‐variable model and a two‐dimensional shallow‐water model, is now explored in WRF/DART with real observations using a Cross Appalachian Tracer Experiment case from September 1983 (CAPTEX‐83). The HNEnKF, effectively combining observation nudging and the ensemble Kalman filter (EnKF), achieves a more gradual data assimilation and greatly reduces the insertion noise compared to the EnKF.
Fracture Nucleation in Single-Wall Carbon Nanotubes Under Tension: A Continuum Analysis Incorporating Interatomic Potentials

Carbon nanotubes show great promise for applications ranging from nanocomposites, nanoelectronic components, nanosensors, to nanoscale mechanical probes. These materials exhibit very attractive mechanical properties with extraordinarily high stiffness and strength, and are of great interest to researchers from both atomistic and continuum points of view. In this paper, we intend to develop a continuum theory of fracture nucleation in single-walled carbon nanotubes by incorporating interatomic potentials between carbon atoms into a continuum constitutive model for the nanotube wall. In this theory, the fracture nucleation is viewed as a bifurcation instability of a homogeneously deformed nanotube at a critical strain. An eigenvalue problem is set up to determine the onset of fracture, with results in good agreement with those from atomistic studies. ©2002 ASME
The 2017 human monkeypox outbreak in Nigeria—Report of outbreak experience and response in the Niger Delta University Teaching Hospital, Bayelsa State, Nigeria

Background In September 2017, Nigeria experienced a large outbreak of human monkeypox (HMPX). In this study, we report the outbreak experience and response in the Niger Delta University Teaching Hospital (NDUTH), Bayelsa state, where the index case and majority of suspected cases were reported. Methods In a cross-sectional study between September 25th and 31st December 2017, we reviewed the clinical and laboratory characteristics of all suspected and confirmed cases of HMPX seen at the NDUTH and appraised the plans, activities and challenges of the hospital in response to the outbreak based on documented observations of the hospital’s infection control committee (IPC). Monkeypox cases were defined using the interim national guidelines as provided by the Nigerian Centre for Disease Control (NCDC). Results Of 38 suspected cases of HMPX, 18(47.4%) were laboratory confirmed, 3(7.9%) were probable, while 17 (18.4%) did not fit the case definition for HMPX. Majority of the confirmed/probable cases were adults (80.9%) and males (80.9%). There was concomitant chicken pox, syphilis and HIV-1 infections in two confirmed cases and a case of nosocomial infection in one healthcare worker (HCW). The hospital established a make-shift isolation ward for case management, constituted a HMPX response team and provided IPC resources. At the outset, some HCWs were reluctant to participate in the outbreak and others avoided suspected patients. Some patients and their family members experienced stigma and discrimination and there were cases of refusal of isolation. Repeated trainings and collaborative efforts by all stakeholders addressed some of these challenges and eventually led to successful containment of the outbreak. Conclusion While the 2017 outbreak of human monkeypox in Nigeria was contained, our report reveals gaps in outbreak response that could serve as lessons to other hospitals to strengthen epidemic preparedness and response activities in the hospital setting.
ON THE DETERMINATION OF THE NUMBER OF REGIMES IN MARKOV‐SWITCHING AUTOREGRESSIVE MODELS

Abstract. Dynamic models with parameters that are allowed to depend on the state of a hidden Markov chain have become a popular tool for modelling time series subject to changes in regime. An important question that arises in applications involving such models is how to determine the number of states required for the model to be an adequate characterization of the observed data. In this paper, we investigate the properties of alternative procedures that can be used to determine the state dimension of a Markov‐switching autoregressive model. These include procedures that exploit the ARMA representation which Markov‐switching processes admit, as well as procedures that are based on optimization of complexity‐penalized likelihood measures. Our Monte Carlo analysis reveals that such procedures estimate the state dimension correctly, provided that the parameter changes are not too small and the hidden Markov chain is fairly persistent. The use of the various methods is also illustrated by means of empirical examples.
Modeling ocean‐bottom reflection loss measurements with the plane‐wave reflection coefficient

Ocean‐bottom reflection loss has been measured at an abyssal plain site in the northeast Pacific Ocean. The layer of unconsolidated sediment at this site is thin (less than 200 m), and the near‐surface sediments are composed of strongly reflecting sandy turbidites. In consequence, the surficial sediments and the relatively shallow substrate must be accounted for in describing the bottom loss measurements. The bottom loss has been modeled in this paper using the plane‐wave reflection coefficient calculated for a geoacoustic model of the bottom developed from seismic profiling experiments carried out at the site. In the model the sediment column is described by fluid layers with a relatively small value of attenuation and a large value of sound‐speed gradient in the surficial layer, and the substrate is assumed to be a solid. The bottom loss measurements are presented in 1/3 octave bands at 40, 80, and 160 Hz. The results are well‐modeled at small grazing angles (θ≤20°) where the interaction is confined to the surficial sediments. At larger grazing angles the importance of including a solid substrate is demonstrated.
Evaluation of efflux pump inhibitory activity of some plant extracts and using them as adjuvants to potentiate the inhibitory activity of some antibiotics against Staphylococcus aureus

Background: Antibiotic-resistant pathogens became a real global threat to human and animal health. This needs to concentrate the efforts to minimize and control these organisms. Efflux pumps are considered one of the important strategies used by bacteria to exclude harmful materials from the cell. Inhibition of these pumps can be an active strategy against multidrug resistance pathogens. There are two sources of efflux pump inhibitors that can be used, chemical and natural inhibitors. The chemical origin efflux pump inhibitors have many toxic side effects while the natural origin is characterized by a wide margin of safety for the host cell. Aim: In this study, the ability of some plant extracts like (propolis show rosemary, clove, capsaicin, and cumin) to potentiate the inhibitory activity of some antibiotics such as (ciprofloxacin, erythromycin, gentamycin, tetracycline, and ampicillin) against Staphylococcus aureus pathogen were tested. Methods: Efflux pump inhibitory activity of the selected plant extracts was tested using an ethidium bromide (EtBr) accumulation assay. Results: The results have shown that Propolis has a significant synergistic effect in combination with ciprofloxacin, erythromycin, and gentamycin. While it has no effect with tetracycline or ampicillin. Also, no synergic effect was noticed in a combination of the minimum inhibitory concentration for the selected plant extracts (rosemary, clove, capsaicin, and cumin) with any of the tested antibiotics. Interestingly, according to the results of the EtBr accumulation assay, Propolis has potent inhibitory activity against the S. aureus (MRS usa300) pump system. Conclusion: This study suggests that Propolis might act as a resistance breaker that is able to restore the activity of ciprofloxacin, erythromycin, and gentamycin against S. aureus strains, in case of the efflux-mediated antimicrobial resistance mechanisms.
Prevalence of Exfoliative Syndrome in Patients Scheduled for Cataract Surgery: A Review of 110 Cases

Background: Capsular pseudoexfoliation syndrome (CEP) is an age-related systemic disorder of unknown etiology defined by the abnormal production and deposition of pseudoexfoliative fibrillar material both in the anterior segment and in several extraocular tissues [1, 2]. CEP is associated with the development of glaucoma, cataract and zonular instability. It is also responsible for specific surgical complications. Hence the interest to evaluate the prevalence of exfoliative syndrome in patients scheduled for cataract surgery and to shed light on its clinical and surgical particularities. Patients and methods: This is a retrospective, descriptive study involving 110 patients, admitted for cataract surgery, in the adult ophthalmology department, Hospital 20 August in Casablanca, from January 1, 2021 to January 2022. Patients underwent extraction by phacoemulsification or manual extraction with placement of an intraocular implant. Results: This study included 110 patients. The mean age was 66.67 years with a slight predominance of the female gender at 56% versus 44%. The percentage of PEC increases with age. Mean intraocular pressure was significantly higher in eyes with PES than in those without PES. The presence of PES increases the risk of intraoperative and postoperative complications, regardless of the surgical technique, regarding zonular rupture and vitreous exit. Conclusion: The exfoliative syndrome remains a frequent pathology in elderly subjects with cataracts, whose prevalence increases significantly over the age of 60. Its presence constitutes an important risk factor for primary open-angle glaucoma and increases the risk of intraoperative complications during cataract surgery, regardless of the technique used. The key points in surgery are the surgeon's experience and good dilatation.
The mini-QSO's contribution to cosmic reionization

By employing an improved simulation of the evolution of black holes (BHs) based on the merger tree of dark matter halos, we explore the relationship between the central BH mass M bh and velocity dispersion σ * at high redshift z ≥ 6 and quantify the mini-QSO's (with BH mass M = 200 - 105 M ⊙ ) contribution to cosmic reionization. The simulation demonstrates how seed BHs migrate onto the M BH -σ * relation by merging with each other and accreting gas at z ≥ 6: 1. The correlation between BHs and their host halos increases as the BHs grow; 2. The slope, i.e. Φ = d log( M bh )/d log(σ * ) in the relationship, is insensitive to the redshift at z > 6. In agreement with previous work, we find that mini-QSOs' ionizing capability to the Universe lies in the range ~ 25% - 50% if early miniquasars have extremely high duty cycles, i.e. P ( z > 6) ~ 0.9 - 1.
Taylor dispersion in porous media. Determination of the dispersion tensor

In homogeneous porous media, the analytical expression of the dispersion tensor D* can be calculated by the method of moments and by a multiple scale expansion; the symmetric component of this tensor is identical in both cases. Numerically, D* can be computed by two methods, namely the B equation and random walks. The porous media are modeled as being spatially periodic; D* is determined as a function of the Peclet number for four types of unit cells: deterministic, fractal, random, and reconstructed. A systematic comparison is made with existing numerical and experimental data. The long time behavior, and its Gaussian limit, is documented.
Rank-Based Analysis of the Heteroscedastic Linear Model

Abstract Heteroscedasticity often causes problems in the analysis of linear models. Frequently for such cases, scale is a function of the response. Here, for such models, a methodology is presented based on well-known rank-based procedures. The procedure is iterative. Using the residuals from an initial R estimate of the regression coefficients, scale is estimated by inverting a linear rank test for scale. This in turn leads to a weighted R estimate of the regression coefficients and then to a final estimate of scale. Asymptotic linearity results for these estimates are derived, from which their asymptotic distribution is obtained. The weighted R estimate has the same asymptotic distribution as the optimal (known scale) R estimate; hence it is efficiently robust. Consistent estimates of the standard errors of the R estimates of scale and the regression coefficients are determined. Based on these results, a complete inference for the regression coefficients and the scale parameter is realized, including a .
The matrix pencil method for two-dimensional direction of arrival estimation employing an L-shaped array

An algorithm to estimate angles of arrival (azimuth and elevation) and polarization associated with narrow-band plane waves is presented. Electromagnetic energy is assumed to be collected by an L-shaped array of small crossed dipoles. The estimation of the directions of arrival is based on the matrix pencil method, whereas polarization is obtained via a least squares problem.
Should I use digital storytelling in my future classroom? Why or why not? Investigating pre-service math teachers’ acceptance of digital storytelling

The purpose of this study is to investigate digital storytelling based on the technology acceptance model. For this aim, the study was conducted as a case study with the participation of 52 pre-service mathematics teachers. The findings firstly showed that most of the pre-service teachers’ perceived ease of use was high as they consider digital storytelling contributed to the learning environment and their professional development. It was additionally observed in participant responses that their usefulness perceptions are high. Consequently, most pre-service teachers intend to use digital storytelling in their future teaching practices. It was finally revealed that some of the pre-service teachers stated their intention of their students’ participation in the digital storytelling process, while others expressed their intention of bringing their own digital stories to the classroom as educational material.
What Possibilities, Problems and Barriers Do Patients, Suffering from Severe Mental Illness or Alcohol Use Disorder, Perceive Towards Lifestyle Changes or Treatment Seeking to Prevent Cardiovascular Health Problems

Patients suffering from either severe mental illness or alcohol use disorder thus lose 13 to 30 years of life expectancy. The leading cause of death is insufficient detection, diagnoses and treatment of cardiovascular disease. Several interventions aimed at reducing the risk of cardiovascular disease have been developed and tested in randomized controlled trial studies. The interventions tested so far has not shown to have a long-term impact on the health of these patients. Only a few studies have investigated this particular patient group’s perspectives and recommendations on how to prevent and treat risk factors for cardiovascular disease. The aim of this study was to learn about the patients’ perception of physical health problems, have them identify potential barriers for lack of treatment and prevention of cardiovascular disease, and to obtain knowledge for future interventions. The study was designed as a qualitative study and consisted of semi-structured interviews with patients. Two main themes, motivation and continuity/flexibility, and a number of subthemes were identified. Patients wanted healthcare professionals to be more aware of somatic health and that physical health could be better integrated into psychiatry and in the alcohol treatment facility and the possibility of flexible courses adapted to the individual patient.
An inequality of Araki-Lieb-Thirring (von Neumann algebra case)

For a trace τ on a semifinite von Neumann algebra we will prove τ((b 1/2 ab 1/2 ) rp )≤τ((b r/2 a r b r/2 ) p ). Here, r≥1, p>0, and a, b are positive operators
New sociable numbers

An exhaustive search has yielded new sociable groups; one of order 9, two of order 8, and the others of order 4. For each natural number n, we write s(n) = C(n) n for the number of its divisors excluding itself. If this function is iterated by s +1 (n) =s(s(n)), it defines the so-called aliquot sequence of n: s0(n), sl (n), s2(n), . , starting with s0(n) n. If the sequence for a given n is bounded, either it ends at 0 (since s(0) is undefined), or it becomes periodic. If it is constant, it has reached a perfect number. If it is alternating, it represents a pair of amicable numbers, or in general produces after k iterations a cycle s k+ (n), s k+2(n), . , s k+t(n) of minimal length t, which forms a sociable group of order t. There is a concise historical survey on the search for perfect numbers in [1], and thousands of amicable pairs are known today [2], but much less is known about groups of higher order. At the beginning of this century, the first two examples, order 5 and order 28, were found by Poulet [3]. In 1969 and 1970, Borho [41 and Cohen [5] discovered some of order 4. This work was extended some years later by Devitt et al. [6] and Root [7], who found five further groups of order 4. In order to find more examples, I initiated a search for sociable numbers on several computers. Testing the first t iterates of each number n, I used about 10000 cpu hours on HP320/HP330 computers. limit of n max order of t 5 10 50 5 . 105 40 5 *l106 30 5 *107 20 5 . 108 10 5 *109 30* Received November 30, 1989. 1980 Mathematics Subject Classification (1985 Revision). Primary 1 lA25.
A Rare Presentation of Gastrointestinal Stromal Tumor Causing Gastroduodenal Intussusception

Adult intussusception is exceedingly rare and most commonly occurs in the stomach or ileum. It is less common for adult intussusception to be classified as gastroduodenal, which also carries a higher mortality rate. Adult intussusception usually warrants surgical intervention as the underlying cause is often malignancy. However, rarely, the etiology is a gastrointestinal stromal tumor (GIST). Here, we present the case of a patient who presented with abdominal pain, vomiting, and hemorrhagic shock and was diagnosed with gastroduodenal intussusception secondary to a gastric GIST.
Spectral variations in the low-mass X-ray binary 4U 0614+09

We report the X-ray spectra of a binary 4U 0614+09 observed with EXOSAT on five different occasions in 1984 and 1986. In four observations in 1984, the source intensity was 'low' compared to its intensity in the 1986 observation. The source was steady on timescales of 10 to 1000 s in each of the 1984 observations but highly variable during the 1986 variations. The best-fit spectral models for the continuum are a blackbody spectrum plus an emission from a Comptonized region. In addition, a component due to reflection from a cold disk around the source was needed as an absorbiton edge due to cold or ionized iron was seen near 7 keV with good significance in most of the spectra, particularly in the 'low' state. The relation of the hardness ratios with intensity follow the behavior seen in the 'Atoll' sources. We have studied the behavior of the hardness ratios with the variations in the parameters of the best-fit spectral models. Most of the variability is associated with the blackbody component thought to arise from the boundary layer on the surface of the neutron star. During the 'high' state in 1986, the blackbody temperature is higher, its size smaller, and its contribution significantly greater than in the 'low' state. The other notable difference between the two states is the lower opacity in the Comptonized region, and a significantly higher absorption in the 'high' state. A weak line emission (equivalent width = 10 to 40 eV) is detected during the 'high' state. The line energy lies between 6 and 7 keV wh ich implies its origin from ionized iron.
Dependence of dynamic shear modulus of uniform sands on stress level and density

The first part of this study is a description and analysis of experimental investigations conducted to determine the nonlinear stress–strain behaviors of uniform sands when subjected to cyclic loadings at small strain levels. A series of torsional shear tests are performed under undrained conditions to analyze the variations in the stress–strain properties of saturated uniform sands consolidated to specified confining stresses and with certain relative densities. The role of effective confining pressure on the cyclic properties of isotropically consolidated sands is also considered. The second part of the study uses nonlinear multiple regression, neural network, and adaptive neuro-fuzzy inference methodologies to identify the complex mappings that range from void ratio and confining pressure input spaces to dynamic shear modulus output space. Test results and model comparisons are presented and evaluated in detail.