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As the main contribution of this article, we establish an option on a credit spread under a stochastic interest rate. The intense volatilities in financial markets cause interest rates to change greatly; thus, we consider a jump term in addition to a diffusion term in our interest rate model. However, this decision leads us to a partial integral differential equation. Since the integral part might bring some difficulties, we put forward a fairly new numerical scheme based on the alternating direction implicit method. In the remainder of the article, we discuss consistency, stability, and convergence of the proposed approach. As the final step, with the help of the MATLAB program, we provide numerical results of implementing our method on the governing equation.

Introduction Fractional Differential Calculus (FDC) began in the 17th century and its initial discussions were related to the works of Leibniz, Lagrange, Abel and others. In recent decades, the fractional differential equations have been considered in different fields such as fluid flow, electromagnetics, engineering, economics and finance. In the early 1970s, Black and Scholes introduced their famous model for pricing option. This model is one of the most popular models in the financial market and plays an important role in determining the price of a high-risk asset in financial modeling field. In this equation, researchers seek to obtain the option value by numerical or analytical methods or to extract new pricing models that reflect the real financial market. The Black-Scholes equation is based on some assumptions which caused constraints in the market. Some advanced models such as jump-diffusion, stochastic interest rate, and stochastic volatility models have been proposed to remove these constraints. Wang and Meng (2010) show that the distribution of stock returns have long-range dependence property which is not consistent with the classical Black -Scholes equation assumptions. This led us to use the ​​fractional modeling in this paper which is derived by applying the fractional specifications of stock market suggesting by Mandelbrot (1963). So, in this paper, we reach to the fractional Black-Scholes model by replacing fractional Brownian motion instead of standard Brownian motion in the classical Black-Scholes equation. The fractional Black-Scholes equation gives better solutions than classical Black-Scholes model to our data which their distribution of stock price depend on long-range. So, in this paper, we solve the fractional Black- Scholes equation and use the combination of radial basis functions and finite difference methods to solve the fractional Black-Scholes equation. This method is flexible because it does not depend on the position of points, and in comparison with other methods, it has a short run time in high dimensions. Material and methods In this paper, we reach to the fractional Black-Scholes equation by using the fractional underlying asset that follows the fractional Brownian motion. The model represents the price behavior of an European option. It is based on the stochastic behavior of underlying asset which is priced by fractional models. We also apply the radial basis function method to solve this model. In this method, we do not necessarily need to have points with equal distances and the convergence rate can be exponential. Therefore, this method can provide more acceptable solutions than the other numerical methods. It should be noted that the fractional derivative of the pricing function is approximated by the Caputo fractional derivative. The stability of the proposed method has also been studied. Results and discussion In this paper, we provide the numerical results for the fractional Black-Scholes equation on real data of the coin option by radial basis function method. We receive the data of working days from 95/10/01 to 96/01/06 from Tehran Stock Exchange website by Excel software and uploaded them to MATLAB software format. The parameters required by the model are also estimated by using data. We obtain option price for different α by using these parameters and present the results in figures. Figures show that if the price of the underlying asset is lower than the exercise price, the option price decreases by the increasing of the fractional order (α), which means that if the holder chooses not to exercise the contract, he will incur less loss. Increasing α plays an important role in decreasing option price, if the option price decreases, the increasing α will make the purchaser incur less loss. On the other hand, when α increases, if the underlying asset price is above the strike price, the call option price increases, and the holder will make a gain by exercising it. We also predict the price of the coin for the next 5 days by different α. The results are presented in a table and are compared with real price of the market, which show that the method is efficient and the fractional Black-Scholes equation has better performance than the classical Black-Scholes equation. Conclusion The purpose of this paper is to model the fractional Black -Scholes equation and to solve it by radial basis function method. First we modeled the fractional Black-Scholes equation by using fractional underlying asset and then we solved this equation by radial basis function method. Finally, the efficiency of this method is shown by using the real data of the coin option. The numerical results present that the method is efficient, and the fractional Black-Scholes equation performs better than the classical Black- Scholes equation .The existence of α in the fractional Black -Scholes equation has drawn the prices closer to the real price../files/site1/files/64/11.pdf

Introducción. La Organización Mundial de la Salud (OMS) recomienda la realización de estudios representativos a nivel nacional para estimar la prevalencia de la resistencia pre- tratamiento del VIH a los antirretrovirales (PDR) para evaluar la efectividad de las terapias de primera línea. El objetivo del presente estudio fue determinar la prevalencia de PDR en adultos cubanos infectados por el VIH-1. Métodos. Se determinó la resistencia del VIH a los antirretrovirales a 610 pacientes cubanos en dos períodos de tiempo (469 pacientes entre 2009-2016 y 141 pacientes durante la encuesta nacional de PDR del VIH-1 efectuada durante el año 2017, según las recomendaciones emitidas por la OMS). Resultados y Discusión. En el período 2009-2016, el 19 % de los pacientes presentaron virus con alguna mutación aso- ciada a la PDR del VIH-1 a los antirretrovirales (10,4 % a algún inhibidor de la transcriptasa inversa análogo de nucleósidos (ITIAN), 12,8 % a algún inhibidor de la transcriptasa inversa no análogo de nucleósidos (ITINAN), 2,8 % a algún inhibidor de proteasa (IP). En el año 2017, la prevalencia de PDR fue de 29,8 % (95 %, IC 22,3-38,1). La prevalencia fue de 10,6 % (95 %, IC 6,07-16,9) para algún ITIAN, 23,4 % (95 %, IC 16,7-31,3) para algún ITINAN y 1,4 % (95 %, IC 0,17-5,03) para algún IP. Se concluyó que los valores por encima del 10 % en la prevalencia de la PDR a los ITINAN evidencia el comprometimiento de la primera línea de terapia antirretro- viral empleada en Cuba y la necesidad de buscar nuevas opciones de tratamiento.

This paper considers the vehicle control process in emergency lane change (ELC). The control method is divided into two parts: before crossing the obstacle and after crossing it. The first part is done by a feed-forward controller inspired by the driver's behavior pattern in the ELC maneuver. This controller is compensated by a neural network system and two proportional-integral (PI) and proportional-derivative (PD) controllers, which correct the output of the feed-forward controller to follow the path more accurately. The second part consists of two PD controllers responsible for controlling and steering the vehicle in the main path after crossing the obstacle. The main novelty of the proposed method is that the computational burden is low because of using a feed-forward controller, which is the main source of the calculation's burden. So as a result, the controller system can cover the ELC maneuver in under 2 seconds in various lateral displacements to bypass the obstacle and prevent collisions. The co-simulations are performed in CarSim software and MATLAB/Simulink, which shows that the control system can appropriately steer the vehicle and follow the desired at different speeds, in the presence of road friction and parameter uncertainty. [ABSTRACT FROM AUTHOR]

Copyright of Mendive - Revista de Educacion is the property of Universidad de Pinar del Rio and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: The presence of antiretroviral-resistant human immunodeficiency virus (HIV)-1 genetic variants in patients with late presentation to health care may impact the success of antiretroviral therapy (ART), costs of care, and potential HIV transmission. Aim: To determine the prevalence of pre-treatment HIV-1 drug resistance to antiretrovirals (pre-treatment HIV-1 drug resistance (PDR)) in Cuban patients classified as late presenters (LPs). Methods: A retrospective cross-sectional study was carried out on 255 HIV-positive Cubans classified as LP (CD4+ T cell count ≤ 350 cells/mm3) and included in PDR surveillance studies in Cuba during the period 2009--2020. The viral subtype and the genotypic profile of antiretroviral resistance were analyzed. Some clinical and epidemiological variables were evaluated. Results: 83.2% of the patients were male and 65.9% were men who had sex with other men. The average age was 31 years. 40% of the individuals studied had advanced disease (CD4+ T cell count ≤200 cells/mm3). The predominant genetic variants were subtype B (29.4%); CRF20, 23, 24_BG (24.3%), and CRF19_cpx (22.4%). The prevalence of pre-treatment HIV-1 drug resistance (PDR) was 21.2% (95%, CI 16.3-26.7). The prevalence was 8.2% (95%, CI 5.3-11.9) for any nucleoside reverse transcriptase inhibitor (NRTI), 15.1% (95%, CI 11.2-19.7) for any non-NRTI (NNRTI), and 2.1% (95%, CI 0.75-4.41) for any protease inhibitor (PI). 9.25% of the LPs with PDR died a year after diagnosis of the HIV infection. The most frequent mutations were K103N (6.7%), G190A (4.7%), and M184V (4.3%). The treatment will not be effective in 17.3% of patients who start therapy with the NRTI + NNRTI combinations. Conclusion: The high PDR values in LPs show the need to enhance genotypic studies of HIV resistance in this population at the time of diagnosis of the infection, since the success of first-line ART may be compromised and influence compliance with the global goals set forth by United nations acquired immunodeficiency syndrome for the year 2030. [ABSTRACT FROM AUTHOR]

Context: The implementation of a strategy of Integrated Pest Management is based on characterization of pests and crops, and the relationships existing between the two. Objective: To determine the structure, abundance, and relative frequency of phytophagous insects associated to bean variety Bat-304. Methods: Research took place on San Miguel Farm, Jaruco, Mayabeque, at two different sowing times: On September 5, 2015 (early), and February 18, 2016 (late). Overall, six samplings were made 15 days after sowing, at a weekly rate. Samples were collected from 15 plants at random, double diagonal, for which a leaf was taken from each level, (higher, middle, lower). The samples taken were analyzed at the Entomology Laboratory of the Faculty of Agronomy, Agrarian University of Havana, for quantification and identification of several species. Results: The phytophagous insects detected were, Empoasca kraemeri Ross and Moore; Bemisia tabaci Gennadius; Liriomyza trifolii Burgess; Thrips palmi Karny; Diabrotica balteata Leconte and Cerotoma ruficornis Olivier.). T. palmi was very abundant during the two sowing times, whereas L. trifolii was not as abundant in either time. E. kraemeri and B. tabaco were variably abundant at each sowing time. Conclusions: Phytophagous insects kraemeri; B. tabaci; L. trifolii, and T. palmi, were very abundant at the two sowing times. A greater biological diversity was observed in sowing time 1 (early), whereas dominance was higher during sowing time 2 (late).

Crude oil commercial stocks are one of the main components of the oil market, and its fluctuations are important in the analysis of the oil market. The purpose of this study is to investigate the unprecedented accumulation of crude oil commercial stocks according to structural shocks and convenience yield, since the onset of crude oil prices decline. In this study, the effect of structural shocks on fluctuations of crude oil commercial stocks was analyzed in the form of a structural vector auto regression model (SVAR) over the period from 2006 to 2016. Also, for the first time, convenience yield is calculated using the inverse problem method. This paper has two innovations. First, it is the first time that convenience yield is calculated in the oil market using the inverse problem method. Second, for the first time, the dynamics of crude oil commercial stocks are analyzed expanding Killian’s SVAR Model (2009).The results show that from late 2014 onwards, mostly crude oil supply shocks and crude oil inventory demand shocks have contributed to oil commercial accumulation. Also results show that WTI futures term structure (spread) has been in contango based on the negative net convenience yield since October 2014 and has led to accumulating more crude oil commercial stocks with speculative purposes.

Employing various mathematical tools in machine learning is crucial since it may enhance the learning problem's efficiency. Dynamic systems are among the most effective tools. In this study, an effort is made to examine a kind of machine learning from the perspective of a dynamic system, i.e., we apply it to learning problems whose input data is a time series. Using the discretization approach and radial basis functions, a new data set is created to adapt the data to a dynamic system framework. A discrete dynamic system is modeled as a matrix that, when multiplied by the data of each time, yields the data of the next time, or, in other words, can be used to predict the future value based on the present data, and the gradient descent technique was used to train this matrix. Eventually, using Python software, the efficacy of this approach relative to other machine learning techniques, such as neural networks, was analyzed. [ABSTRACT FROM AUTHOR]

Background & Objective: Oxidative stress is associated with the pathology of various neuropsychiatric disorders, such as depression and anxiety. The aim of the study was to examine the impacts of the lavender aqueous extract (LAE) on the levels of oxidative stress markers in an animal model with chronic mild stress induced depression. Materials & Methods: 36 adult male Sprague-Dawley rats were haphazardly split into 6 groups (n=6). Rats in the test groups were put through five weeks of chronic mild stress. The sucrose preference test (SPT) confirmed depressive-like behaviors in the rats. Rats in both unstressed and stressed control groups received LAE (200 or 400 mg/kg) and distilled water respectively. The specific activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (Gpx), malondialdehyde (MDA) and as well as the total content of glutathione (GSH) were examined in the serum, liver and prefrontal cortex (PFC) using colorimetric assays. Results: The stress group experienced a significantly decreased level of GSH, SOD, GR, Gpx and CAT, and a statistically considerable augment in MDA level in in the serum, PFC and liver p<0.05. LAE at both doses significantly reversed the depression-caused oxidative stress markers in all the studied tissues. No significant difference was observed between the two used dosages of LAE. Conclusion: LAE is able to ameliorate depression-induced pathology possibly through anti-oxidant activity. [ABSTRACT FROM AUTHOR]

Copyright of Acta Médica del Centro is the property of Hospital Provincial Universitario Clinico Quirurgico Arnaldo Milian Castro and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Médica del Centro is the property of Hospital Provincial Universitario Clinico Quirurgico Arnaldo Milian Castro and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Recent decade was undoubtedly a uniqe one for the banking and financial sector in Iranian economy. Stock market index was breaking records now and then, new credit institutions were established one after another, and different banks were competing in raising their interest rates of deposits. Put this story alongside an unprecedented bubble in construction sector in years 2006 and 2007, and we can realize that real sectors of the economy, specially industry and agriculture, were in what circumstances. Whatever is our definition of development and whatever is our index for measuring it, we cannot deny the fact that the reliable development is the one which is balanced and can cause growth in all sectors in a homogeneous and proportional way. One of important factors in analysing the situation of these sectors, is the credit ranking and grading that they have been able to get based on their performance from banking and financial system. Therefore, measuring credit risk in these sectors can make a good impression on their performance for policy-makers in each sector and economist involved with the issue. In this paper, we are going to calculate and analyze credit risk in different sectors of Iranian economy, namely “industry”, “agriculture” and “services and housing” sectors by analysing companies accepted in Stock Exchange and OTC markets. Some of the results of this study are high volatility and declining credit risk in industry sector, high and growing volatility in services and housing sector, and low volatility but very high average and declining trend in agriculture sector.

Objetivo: Establecer la utilidad de las aberraciones anteriores y posteriores en niños para detección del queratocono, mediante imágenes de Scheimpflug con el Pentacam® de Oculus Método: Se realizó un estudio retrospectivo comparativo observacional a niños entre 5 y 15 años. Un grupo con córneas sanas y otro con queratocono en estadio 1 y 2. Se estudió: defecto refractivo esférico, defecto cilíndrico, AVMC, queratometría máxima, mínima y media, astigmatismo topográfico y aberraciones anteriores y posteriores. Se aplicó la prueba t de Student no pareada y la prueba de Mann-Whitney cuando no fue posible usar la anterior. Resultados: En casi todas las aberraciones de la superficie anterior excepto el coma primario y secundario horizontal, existían diferencias significativas entre los grupos. En superficie corneal posterior se hallaron diferencias significativas entre los grupos en: el coma vertical primario, aberración esférica primaria, coma y coma-like RMS. En niños con córneas sanas en superficie posterior se hallaron cifras significativas de coma vertical, aberración esférica, coma y coma-like RMS. Entre la superficie corneal anterior y posterior con queratocono se encontraron diferencias en el coma vertical, coma-RMS y coma-like RMS. Conclusiones: Las mediciones de las aberraciones de la superficie anterior medidas por imágenes de Sheimpflug son útiles en la detección precoz de queratocono en niños. Las aberraciones de superficie posterior corneal no son útiles ya que no están acordes a las propiedades ópticas de la córnea.

Objetivo: Determinar la repercusión de la agudeza visual mejor corregida (AVMC) en la calidad de vida relativa a visión (CVRV) de pacientes ancianos operados de catarata mediante facoemulsificación. Método: Se realizó un estudio cuantitativo prospectivo, de pacientes adultos mayores, con diagnóstico de catarata senil. Se utilizó la prueba de independencia de Chi-cuadrado para determinar relación entre las variables. Resultados: La AVMC predominante fue buena, con una ganancia de 5 líneas de la Cartilla de Snellen. Después de la cirugía de catarata, el mayor porcentaje de los pacientes consideraba tener una muy buena CVRV. Se relacionaron los cuestionarios de CVRV VisQoL-15 y el índice de Katz con la AVMC postoperatoria respectivamente, y ambas relaciones resultaron estadísticamente significativas. La mayoría de nuestros pacientes ancianos estaban satisfechos con el resultado visual obtenido luego de la cirugía y la mayoría se correspondían con pacientes con una buena AVMC en el ojo operado. Conclusiones: La facoemulsificación con implante de lente intraocular es un método efectivo y seguro para mejorar la CVRV en ancianos y su capacidad funcional y el índice de función visual VisQoL-15 constituye un instrumento útil de medición de CVRV en adultos mayores después de cirugía de catarata. La satisfacción de los pacientes con sus resultados visuales estaba estrechamente vinculada con AVMC postoperatorias buenas.

Copyright of MediSur is the property of Centro Provincial de Informacion de Ciencias Medicas de Cinfuegos and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: To examine the effect of quercetin on stereological parameters and autophagy-related genes in ovaries of polycystic ovary syndrome (PCOS) rats. Methods: Fifty female Sprague-Dawley rats were randomly divided into five groups: the control group, the ethanol group, the quercetin group (15 mg/kg/day), the PCOS group, as well as the PCOS + quercetin group. After the induction of PCOS, quercetin was administered orally for 30 days. Histological, stereological and real-time PCR analyses were carried out to evaluate the effect of quercetin on PCOS rats. Results: Stereological analysis revealed that quercetin significantly increased the number of ovarian follicles and the volume of corpus luteum and induced a significant decrease in atretic follicles in comparison to the PCOS group. In addition, quercetin markedly increased mTOR gene expression while decreasing Beclin-1 and LC3 gene expression. Conclusions: Quercetin strongly modulates the expression of ovarian autophagy-related genes and stereological parameters in PCOS rats. Therefore, it can be considered as an ameliorative component for ovarian follicular impairments. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Ciencias Médicas de Pinar del Río is the property of Editorial Ciencias Medicas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of TE & ET: Revista Iberoamericana de Tecnología en Educación y Educación en Tecnología is the property of School of Computer Science, La Pata University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)