Integrable models: from dynamical solutions to string theory

We review the status of integrable models from the point of view of their dynamics and integrability conditions. Some integrable models are discussed in detail. We comment on the use it is made of them in string theory. We also discuss the Bethe Ansatz solution of the SO(6) symmetric Hamiltonian with SO(6) boundary. This work is especially prepared for the seventieth anniversaries of Andr\'{e} Swieca (in memoriam) and Roland K\"{o}berle.Comment: 24 pages, to appear in Brazilian Journal of Physic

Frequency of Rotavirus Infection among Children with Diarrhea in Omdurman Pediatric Hospital, Sudan

Background: Rotaviruses are the major cause of gastroenteritis and  diarrhea in infants and young children worldwide. Basic epidemiological data concerning rotaviruses among infants and children are necessary for health planners and care providers in Sudan.Method: Cross-sectional study was conducted at Omdurman Pediatric Hospital, Sudan to investigate the frequency of rotavirus infection and associated possible risk factors among children. The solid-phase sandwich enzyme-linked immunosorbent assay (ELISA) was used to detect rotavirus antigens. Structured questionnaire was used to gather socio-demographic data.Results: Out of 92 diarrheal cases, 23 were rotavirus-antigen positive (25%). Most of the positive subjects (91.3%) were in children less than 3 years of age and the infection rate decreased with the increasing age (p>.05). Children infected with rotaviruses were more likely to have  vomiting (82.6%) (p > 0.05) and fairly low frequency of fever (60.9%) (p > 0.05). Out of the 23 rotavirus positive subjects, 13 (30.2%) were  breast-fed, 6 (25%) were both breast and bottle-fed and 4 (16.6%) were neither breast nor bottle-fed (p > 0.05). Furthermore, the antibiotic treated children revealed the highest percentage of rotavirus antigen (26.9%) compared to the non-treated children (14.3%).Conclusion: Rotavirus frequency was 25% among children less than 5 years. Rotavirus vaccine, routine and proper diagnosis of rotavirus infection in children with acute diarrhea help to determine appropriate treatment, prevents the unnecessary use of antibiotics and minimizes the spread of the disease among susceptible children in Sudan.Keywords: Rotavirus, Antigens, Gastroenteritis, Diarrhea, Infants, Children

The classical origin of quantum affine algebra in squashed sigma models

We consider a quantum affine algebra realized in two-dimensional non-linear sigma models with target space three-dimensional squashed sphere. Its affine generators are explicitly constructed and the Poisson brackets are computed. The defining relations of quantum affine algebra in the sense of the Drinfeld first realization are satisfied at classical level. The relation to the Drinfeld second realization is also discussed including higher conserved charges. Finally we comment on a semiclassical limit of quantum affine algebra at quantum level.Comment: 25 pages, 2 figure

On the classical equivalence of monodromy matrices in squashed sigma model

We proceed to study the hybrid integrable structure in two-dimensional non-linear sigma models with target space three-dimensional squashed spheres. A quantum affine algebra and a pair of Yangian algebras are realized in the sigma models and, according to them, there are two descriptions to describe the classical dynamics 1) the trigonometric description and 2) the rational description, respectively. For every description, a Lax pair is constructed and the associated monodromy matrix is also constructed. In this paper we show the gauge-equivalence of the monodromy matrices in the trigonometric and rational description under a certain relation between spectral parameters and the rescalings of sl(2) generators.Comment: 32pages, 3figures, references added, introduction and discussion sections revise

Are isomeric alkenes used in species recognition among neo-tropical stingless bees (Melipona spp)

The majority of our understanding of the role of cuticular hydrocarbons (CHC) in recognition is based largely on temperate ant species and honey bees. The stingless bees remain relatively poorly studied, despite being the largest group of eusocial bees, comprising more than 400 species in some 60 genera. The Meliponini and Apini diverged between 80-130 Myr B.P. so the evolutionary trajectories that shaped the chemical communication systems in ants, honeybees and stingless bees may be very different. Therefore, the main aim of this study was to study if a unique species CHC signal existed in Neotropical stingless bees, as shown for many temperate species, and if so what compounds are involved. This was achieved by collecting CHC data from 24 colonies belonging to six species of Melipona from North-eastern Brazil and comparing this new data with all previously published CHC studies on Melipona. We found that each of the eleven Melipona species studied so far each produced a unique species CHC signal based around their alkene isomer production. A remarkable number of alkene isomers, up to 25 in M. asilvai, indicated the diversification of alkene positional isomers among the stingless bees. The only other group to have really diversified in alkene isomer production are the primitively eusocial Bumblebees (Bombus spp), which are the sister group of the stingless bees. Furthermore, among the eleven Neotropical Melipona species we could detect no effect of the environment on the proportion of alkane production as has been suggested for some other species

Entomological aspects and the role of human behaviour in malaria transmission in a highland region of the Republic of Yemen

© 2016 Al-Eryani et al. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/ publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. The attached file is the published version of the article

Acceptance and Hesitancy Towards Covid-19 Vaccination Among Dialysis Patients in a Dialysis Center in Khartoum in 2022

Ayah Isam Abdalla, Amna Mutasim Elazrag, Siralkhatim Mohammed, Hassan Hassan Faculty of Medicine, University of Khartoum, Khartoum, SudanCorrespondence: Amna Mutasim Elazrag, University of Khartoum, Faculty of Medicine, Al-Qasr Avenue, Box 11111, Khartoum, Sudan, Tel +249999566300, Email [email protected]: COVID-19, a highly infectious virus, poses significant risks, particularly for immuno-compromised individuals. Vaccination remains a key preventive measure, yet acceptance rates vary among populations globally.Objective: This study aims to assess COVID-19 vaccine acceptance and hesitancy among dialysis patients atDr. Salma Center for Dialysis in 2022, highlighting the primary reasons for hesitancy within this vulnerable group.Methods: A descriptive cross-sectional study was conducted at Dr. Salma Center in Khartoum, Sudan, in 2022. A systematic random sampling method was employed to select participants, who were interviewed using a structured questionnaire.Results: Of a sample of 137 patients, 125 completed the questionnaire with 91.2% response rate. Approximately half of the respondents reported vaccine hesitancy 50%, with 77% acknowledging the severity of COVID-19 but only 53% advised vaccination among their peers. Primary concerns included vaccine side effects 24.8% and mistrust of production companies 10.4%. No significant associations were found between vaccine hesitancy and demographic factors.Conclusion: The study reveals a notable prevalence of COVID-19 vaccine hesitancy among dialysis patients at Dr. Salma Center in Khartoum, 2022. Addressing this hesitancy requires concerted efforts to bridge the trust gap between patients and healthcare systems, coupled with targeted awareness campaigns to correct misinformation and reinforce confidence in vaccines.Keywords: covid-19, SARS-COV-22, vaccine hesitancy, dialysis, ESK

SPARC 2017 retrospect & prospects : Salford postgraduate annual research conference book of abstracts

Welcome to the Book of Abstracts for the 2017 SPARC conference. This year we not only celebrate the work of our PGRs but also the 50th anniversary of Salford as a University, which makes this year’s conference extra special. Once again we have received a tremendous contribution from our postgraduate research community; with over 130 presenters, the conference truly showcases a vibrant PGR community at Salford. These abstracts provide a taster of the research strengths of their works, and provide delegates with a reference point for networking and initiating critical debate. With such wide-ranging topics being showcased, we encourage you to exploit this great opportunity to engage with researchers working in different subject areas to your own. To meet global challenges, high impact research inevitably requires interdisciplinary collaboration. This is recognised by all major research funders. Therefore engaging with the work of others and forging collaborations across subject areas is an essential skill for the next generation of researchers