A hybrid functions numerical scheme for fractional optimal control problems: Application to nonanalytic dynamic systems

In this paper, a numerical scheme based on hybrid Chelyshkov functions (HCFs) is presented to solve a class of fractional optimal control problems (FOCPs). To this end, by using the orthogonal Chelyshkov polynomials, the HCFs are constructed and a general formulation for their operational matrix of the fractional integration, in the Riemann–Liouville sense, is derived. This operational matrix together with HCFs are used to reduce the FOCP to a system of algebraic equations, which can be solved by any standard iterative algorithm. Moreover, the application of presented method to the problems with a nonanalytic dynamic system is investigated. Numerical results confirm that the proposed HCFs method can achieve spectral accuracy to approximate the solution of FOCPs

The Motion of a Bead Sliding on a Wire in Fractional Sense

In this study, we consider the motion of a bead sliding on a wire which is bent into a parabola form. We first introduce the classical Lagrangian from the system model under consideration and obtain the classical Euler-Lagrange equation of motion. As the second step, we generalize the classical Lagrangian to the fractional form and derive the fractional Euler-Lagrange equation in terms of the Caputo fractional derivatives. Finally, we provide numerical solution of the latter equation for some fractional orders and initial conditions. The method we used is based on a discretization scheme using a Grünwald-Letnikov approximation for the fractional derivatives. Numerical simulations verify that the proposed approach is efficient and easy to implement

Antimicrobial resistance patterns and phylogenetic analysis of shiga toxin-producing escherichia coli strains from goats using both clermont phylogenetic schemes

Foodborne transmission of Shiga toxin-producing Escherichia coli (STEC) poses a threat to public health. The Clermont typing schemes (previous and revised) have been used widely to phylotype E. coli. The present study was conducted to compare the relationship of the Clermont phylogenetic schemes in STEC strains isolated from goats and antibiotic resistance patterns in the southeast of Iran. Overall 52 strains carrying the stx gene were used for subsequent analysis. All strains were deter-mined by analysing the genomic DNA with a PCR-based method using the two Clermont et al. (2000, 2013) schemes. Extended spectrum beta-lactamase (ESBL) producing strains were confirmed by the double disk-diffusion method. STEC strains were also tested for susceptibility to 20 antimicrobials agents. In the original Clermont method, the prevalent phylogroups were B1 (69.2) and A (28.8). The significant phylogenetic groups of strains according to the revised Clermont method were B1 (82.7), A (13.5) and unknown (3.8). However, STEC strains underwent changes as noted from A to B1 (17.3), B1 to unknown (3.8), B1 to A (1.9) and D to B1 (1.9) groupings. Of the 52 stx-positive strains, two ESBL producing strains were detected. Susceptibility data showed that the most frequent resistance phenotype was related to cefazolin (90.4), streptomycin (88.5), ampicillin (86.5) and oxytetracycline (82.7) respectively. Although the overall frequency of the reassigned phylotypes was not significant, most changes occurred within the A phylotype. Therefore, implementation of the new method on isolates belonging to the A phylotype in the old method seems to be necessary to obtain accurate results. © 2021, Trakia University. All rights reserved

Detection of zoonotic diarrheagenic pathotypes of escherichia coli in healthy household dogs

Background and Objectives: Intestinal pathotypes of Escherichia coli belong to the companion animals may poses potential risk to public health following zoonotic transmission. Therefore, this study was proposed to determine the virulence genes associated to diarrheagenic E. coli strains isolated from healthy pet dogs and their owners in the southeast of Iran, Kerman province. Materials and Methods: Totally 168 E. coli isolates were collected from 49 healthy household dogs and their owners. Seventy isolates were obtained from non-pet owners as control group. Presence or absence of the virulence genes including eae, stx1, stx2, st1, lt1, ipaH, cnf1 and cnf2 were screened by conventional polymerase chain reaction (PCR) and dissemination pattern of the genes were studied among the various hosts. Results: PCR examinations showed that the most frequent virulence gene was ipaH (6.1) in dogs followed by eae in dog owners (6.1) and in controls (8.6). The most frequent pathotypes in dogs, their owners and controls were EIEC (6.1), EHEC (4.08) and EPEC (8.5), respectively. In one of studied houses, both of dog and its owner harbored E. coli strains with same virulence profile (stx1/eae) and pathotype (EHEC). Conclusion: These results collectively indicate that healthy household dogs probably are the mild reservoir of potential virulent E. coli strains with possible active transmission to their contact owner. However, even non-pet owners seemed to be a notable source of intestinal pathotypes, especially EPEC, for their environment. Transmission of E. coli pathotypes may occurs by direct contact with the reservoirs or ingestion of contaminated food. These pathotypes are potentially virulent and creates public health hazards. Further studies are needed for better understanding of dissemination mechanisms of E. coli pathotypes among humans and their pets. © 2020, Tehran University of Medical Sciences. All rights reserved