Transverse expansion of hot magnetized Bjorken flow in heavy ion collisions

We argue that the existence of an inhomogeneous external magnetic field can lead to radial flow in transverse plane. Our aim is to show how the introduction of a magnetic field generalizes the Bjorken flow. We investigate the effect of an inhomogeneous weak external magnetic field on the transverse expansion of in-viscid fluid created in high energy nuclear collisions. In order to simplify our calculation and compare with Gubser model, we consider the fluid under investigation to be produced in central collisions, at small impact parameter; azimuthal symmetry has been considered. In our model, we assume an inhomogeneous external magnetic field following the power-law decay in proper time and having radial inhomogeneity perpendicular to the radial velocity of the in-viscid fluid in the transverse plane; then the space time evolution of the transverse expansion of the fluid is obtained. We also show how the existence of an inhomogeneous external magnetic field modifies the energy density. Finally we use the solutions for the transverse velocity and energy density in the presence of a weak magnetic field, to estimate the transverse momentum spectrum of protons and pions emerging from the Magneto-hydrodynamic solutions

Non-relativistic approximate numerical ideal-magneto hydrodynamics of (1+1) D transverse flow in Bjorken scenario

In this study, we investigate the impact of the magnetic field on the evolution of the transverse flow of QGP matter in the magneto-hydrodynamic (MHD) framework. We assume that the magnetic field is perpendicular to the reaction plane and then we solve the coupled Maxwell and conservation equations in (1+1D) transverse flow, within the Bjorken scenario. We consider a QGP with infinite electrical conductivity. First, the magnetic effects on the QGP medium at mid-rapidity are investigated at leading order; then the time and space dependence of the energy density, velocity and magnetic field in the transverse plane of the ideal magnetized hot plasma are obtained

Transverse and non-boost longitudinal expansion of (2+1)dimensional relativistic ideal-hydrodynamics flow in heavy ion collisions

This study investigates the evolution of quark gluon plasma (QGP) within a generalized Bjorken flow framework. The medium under consideration is assumed to possess a finite transverse size and to expand both radially and along the beam axis. However, we assume that the boost invariance of longitudinal expansion is broken. To be more specific, we generalize the Bjorken solution to include the acceleration and transverse expansion of the fluid. We analytically study the (2 + 1) dimensional longitudinal acceleration expansion of hot and dense quark matter, applying a perturbation approach to solve the relativistic hydrodynamics equations. This procedure enables us to obtain exact algebraic expressions for fluid velocities and energy densities in both transverse and longitudinal directions. To simplify our calculations, we assume that the fluid is produced in central collisions, and therefore, we consider azimuthal symmetry. We compare the radial velocity and correction energy density with those obtained from the Gubser model. Furthermore, we determine the fluid's acceleration parameter and longitudinal correction energy density, which exhibits a Gaussian distribution

Detection of the efflux-mediated erythromycin resistance transposon in streptococcus pneumoniae

Background: The present analysis focuses on phenotypic and genotypic characterizations of efflux-mediated erythromycin resistance in Streptococcus pneumoniae due to an increase in macrolide resistance in S. pneumoniae worldwide. Methods: We investigated the prevalence of efflux-mediated erythromycin resistance and its relevant genetic elements from 186 specimens of S. pneumonia isolated from clinical and normal flora from Tehran, Iran. The presence of erythromycin resistance genes was tested by PCR with two sets of primers, specific for erm(B) and mef(A/E), and their genetic elements with tetM, xis, and int genes. Isolates were typed with the BOX PCR method and tested for resistance to six antibiotics. Results: Antibiotic susceptibility tests revealed that 100 and 47 isolates were resistant to tetracycline and erythromycin, respectively. The erythromycin and clindamycin double-disc diffusion test for macrolide-lincosamide-streptograminB (MLSB) resistance phenotype showed 74 (84) isolates with the constitutive MLSB phenotype and the remaining with the M phenotype. BOX PCR demonstrated the presence of 7 types in pneumococci with the M phenotype. Fourteen (16) isolates with the M phenotype harbored mef(A/E), tetM, xis, and int genes. Conclusion: The present results suggest dissemination of polyclonal groups of S. pneumoniae with the M phenotype carrying resistance genes attributed to transposon 2009. © The Korean Society for Laboratory Medicine

Determination of characteristics of erythromycin resistant Streptococcus pneumoniae with preferred PCV usage in Iran

Amongst 100 Streptococcus pneumoniae isolated from clinical cases and nasopharynx of healthy individuals, 60 erythromycin resistant strains were isolated and characterized using MLST, PFGE, transposon analysis and Quellung reaction. Most of the S. pneumoniae erythromycin resistant (80) were found to be attributable to the ermB-edncoded ribosome methylase activity which differs from the dominant mechanism of macrolide resistance seen in North America. The most predominant transposons were; Tn 1545/6003(27), Tn6002 (22), Tn2009 (20), Tn2010 (17). Number of the clinical isolates carrying Tn2010 was more significant than the normal flora. The serotypes found were; 14 (33), 3 (22), 23F (15), 19F (15), 19A (7), 6A (3), 9V (3) and 6B (2). The most prevalent serotypes among the clinical (n = 28) and normal flora (n = 32) isolates were serotypes 14 (46) and 3 (31), respectively. The most prevalent vaccine serotypes amongst the clinical isolates and the healthy individuals were pneumococcal conjugate vaccines (PCV) 13 and PCV10, respectively. PFGE revealed 34 pulsotypes with 9 common and 25 single types. Significant number of the normal isolates belonged to CT5 and CT6. On the other hand, significant number of clinical isolates belonged to CT8 as compared to the normal flora isolates. MLST showed 2 dominant sequence types. ST3130 (23) and ST180 (22) were the most predominant sequence types in the clinical and normal isolates, respectively. There was no significant difference in other sequence types between clinical and normal flora isolates. Three polyclonal complexes including Sweden15A -25, Spain23F-1 and Spain9V-3 constituted 58 of the isolates. Our results suggest that the genetic diversity and transposon distribution were high among S. pneumoniae, particularly in the isolates containing erm(B) and double antibiotic resistant genes (erm/mef). The results presented here could influence the change in the current vaccination practices in Iran which currently calls for vaccination with PCV7 or PCV10. � 2016 Talebi et al.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

dy of P53 gene mutations in promoter and exons 2-4 and 9-11 in patient with gastric cancer by PCR-SSCP in Chaharmahal Va Bakhtiari province

Background: Gastric cancer is one of the most important diseases and after lung cancer, is the second cause of cancer death worldwide. Genetic factors including oncogenes and tumor suppressor genes are always contributed in progression of this cancer. The P53 tumor suppressor gene has a broad role in genomic stability and DNA repair. The aim of this study was to determine the P53 gene mutations in gastric cancer specimens in Chaharmahal Va Bakhtiari Province. Methods: In this descriptive-lab based study, we investigated the promoter, exons 2-4 and 9-11 of P53 gene mutations in 38 paraffin embedded gastric cancer specimens. DNA was extracted following the standard phenol chloroform protocol. The P53 gene mutations were determined using PCR-SSCP procedure. Results: Our study revealed no P53 gene mutation in promoter and exons 2-4 and 9-11 in the gastric cancer subjects studied. Conclusion: While P53 gene mutations have been reported as the most frequent genetic alterations and are found in about 50% of the human malignancies, no mutation was detected in this study. The reason may be due to small sample size or mutations on other genes or epigenetic factors

Emerging technologies in emergency situations (guest editorial)

While scholars have identified the coordination mechanisms needed to provide a synchronised response to emergency situations such as natural disasters (Holguín‐Veras et al., 2012; Oloruntoba & Gray, 2006; van Wassenhove, 2006), the processes required to deploy emerging technologies during such situations had received limited attention (Dubey et al., 2020; Queiroz et al., 2020; Remko, 2020). Moreover, while recent scholarly work has considered the importance of organisational and dynamic capabilities in developing industry 4.0 technologies (Roscoe et al., 2019; Xu et al., 2018), the significance of fostering capabilities for the deployment of emerging technologies in emergency situations is under-researched (de Giovanni, 2019; Koh et al., 2019; Sarkis, 2012). More specifically, the scale of disruption caused by COVID-19 has amplified the challenges presented by natural and man-made disasters, increasing the need for new strategies, capabilities, and creativity in responding to emergency situations (Ivanov, 2020; Remko, 2020; Schleper et al., 2021). The aim of this special issue is to understand how organizations and their supply chain partners can build the capabilities and coordination mechanisms required to deploy and utilise emerging technologies in emergency situations. The special issue intends to stimulate a debate among academic scholars, practitioners, and government representatives on the latest advances in emerging technologies and their application in the context of natural and man-made disasters as well as disease outbreaks such as COVID-19

Mutations in GJB2 as Major Causes of Autosomal Recessive Non-Syndromic Hearing Loss: First Report of c.299-300delAT Mutation in Kurdish Population of Iran

Background and Objectives: : Autosomal recessive non-syndromic hearing loss (ARNSHL) with genetic origin is common (1/2000 births). ARNSHL can be associated with mutations in gap junction protein beta 2 (GJB2). To this end, this cohort investigation aimed to find the contribution of GJB2 gene mutations with the genotype-phenotype correlations in 45 ARNSHL cases in the Kurdish population. Subjects and Methods: : Genomic DNA was extracted from a total of 45 ARNSHL families. The linkage analysis with 3 short tandem repeat markers linked to GJB2 was performed on 45 ARNSHL families. Only 9 of these families were linked to the DFNB1 locus. All the 45 families who took part were sequenced for confirmation linkage analysis (to perform a large project). Results: : A total of three different mutations were determined. Two of which [c.35delG and c.-23+1G>A (IVS1+1G>A)] were previously reported but (c.299-300delAT) mutation was novel in the Kurdish population. The homozygous pathogenic mutations of GJB2 gene was observed in nine out of the 45 families (20%), also heterozygous genotype (c.35delG/N)+(c.-23+1G>A/c.-23+1G>A) were observed in 4/45 families (8.8%). The degree of hearing loss (HL) in patients with other mutations was less severe than patients with c.35delG homozygous mutation (p<0.001). Conclusions: : Our data suggest that GJB2 mutations constitute 20% of the etiology of ARNSHL in Iran; moreover, the c.35delG mutation is the most common HL cause in the Kurdish population. Therefore, these mutations should be included in the molecular testing of HL in this populatio