1,182 research outputs found

    The algebraic hyperstructure of elementary particles in physical theory

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    Algebraic hyperstructures represent a natural extension of classical algebraic structures. In a classical algebraic structure, the composition of two elements is an element, while in an algebraic hyperstructure, the composition of two elements is a set. Algebraic hyperstructure theory has a multiplicity of applications to other disciplines. The main purpose of this paper is to provide examples of hyperstructures associated with elementary particles in physical theory.Comment: 13 page

    Features of childhood acute myeloid leukemia in Iran: A report from double center study

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    Acute Myeloblastic Leukemia is one of the important malignancies in children. For better managing the prognosis of this disease, there should be enough information about common features of this malignancy. The aim of this study was to evaluate these common features in children with Acute Myeloblastic Leukemia. A total of 104 eligible children less than 15-year-old have been referred from 2007-2011 to two referral centers for childhood malignancies. Basic epidemiological information recorded in checklists for each individual. Analyzes have been done by SPSS version 22. Out of patients, 57 cases were males (54.8). The male/female ratio was 1.2. The mean age of patients was 6.5 ± 4.3 years. The majority subtypes of patients were M3, M4, non-M3, and M2, respectively. The common molecular abnormalities were t (15;17) and inv (16). Of patients, 19.2 had an early relapse. The mean age of relapse in patients was 6.7 ± 3.9 years. Sixty patients (57.7) were alive, and 44 cases (42.3) died during or after therapy. The three years overall survival rate of patients was 42 in this study. According to our data, AML has the same frequency as compared with data from developing countries. But different epidemiological characteristic was a lower rate of three years overall survival in patients. These data may serve the health authorities for more effective environmental and preventive measurements, purposeful allocation of resources for facilitating upto-date diagnostic and treatment modalities, psychological support programs for respective family members and educational purposes. © 2015 Tehran University of Medical Sciences. All rights reserved

    Molecular Epidemiology of Cryptosporidiosis in Iranian Children, Tehran, Iran

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    Background: Cryptosporidium is a worldwide protozoan parasite and one of the most common causes of infection and diarrhea in humans and cattle. The aim of the present study was determina­tion of subtypes of Cryptosporidium among children with diarrhea in Tehran by se­quence analysis of the highly polymorphic 60-kDa glycoprotein (GP60) gene.Methods: Fecal samples were collected from 794 diarrheic children. Initial identification of Crypto­spo­ridium was carried out on stool samples by Ziehl-Neelsen acid-fast staining method. DNA was extracted from positive microscopically samples and Cryptosporidium genotypes and subtypes were determined, accordingly."nResults: Out of 794 collected samples, 19 (2.40 %) were positive for Cryptosporidium oocysts. Sequences analysis of GP60 gene showed that 17 (89.47 %) of the positive isolates were Crypto­spori­dium parvum and 2 (10.52 %) were C. hominis. All subtypes of C. parvum isolates belonged to allele families IIa (6/17) and IId (11/17). The most common allele in all 17 isolates belonged to IId A20G1a (41.18%). A22G1 (IF) subtype was detected in two C. hominis isolates of the chil­dren."nConclusion: The predominancy of C. parvum species (specially, IId A20G1a sub­type) in current study underlines the importance of zoonotic Cryptosporidium transmission in Iran

    The ortho-to-para ratio of ammonia in the L1157 outflow

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    We have measured the ortho-to-para ratio of ammonia in the blueshifted gas of the L1157 outflow by observing the six metastable inversion lines from (J, K) = (1, 1) to (6, 6). The highly excited (5, 5) and (6, 6) lines were first detected in the low-mass star forming regions. The rotational temperature derived from the ratio of four transition lines from (3, 3) to (6, 6) is 130-140 K, suggesting that the blueshifted gas is heated by a factor of ~10 as compared to the quiescent gas. The ortho-to-para ratio of the NH3 molecules in the blueshifted gas is estimated to be 1.3--1.7, which is higher than the statistical equilibrium value. This ratio provides us with evidence that the NH3 molecules have been evaporated from dust grains with the formation temperature between 18 and 25 K. It is most likely that the NH3 molecules on dust grains have been released into the gas phase through the passage of strong shock waves produced by the outflow. Such a scenario is supported by the fact that the ammonia abundance in the blueshifted gas is enhanced by a factor of ~5 with respect to the dense quiescent gas.Comment: 16 pages, including 3 PS figures. To appear in the ApJ (Letters). aastex macro

    Non-negative data-driven mapping of structural connections with application to the neonatal brain

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    © 2020 Mapping connections in the neonatal brain can provide insight into the crucial early stages of neurodevelopment that shape brain organisation and lay the foundations for cognition and behaviour. Diffusion MRI and tractography provide unique opportunities for such explorations, through estimation of white matter bundles and brain connectivity. Atlas-based tractography protocols, i.e. a priori defined sets of masks and logical operations in a template space, have been commonly used in the adult brain to drive such explorations. However, rapid growth and maturation of the brain during early development make it challenging to ensure correspondence and validity of such atlas-based tractography approaches in the developing brain. An alternative can be provided by data-driven methods, which do not depend on predefined regions of interest. Here, we develop a novel data-driven framework to extract white matter bundles and their associated grey matter networks from neonatal tractography data, based on non-negative matrix factorisation that is inherently suited to the non-negative nature of structural connectivity data. We also develop a non-negative dual regression framework to map group-level components to individual subjects. Using in-silico simulations, we evaluate the accuracy of our approach in extracting connectivity components and compare with an alternative data-driven method, independent component analysis. We apply non-negative matrix factorisation to whole-brain connectivity obtained from publicly available datasets from the Developing Human Connectome Project, yielding grey matter components and their corresponding white matter bundles. We assess the validity and interpretability of these components against traditional tractography results and grey matter networks obtained from resting-state fMRI in the same subjects. We subsequently use them to generate a parcellation of the neonatal cortex using data from 323 new-born babies and we assess the robustness and reproducibility of this connectivity-driven parcellation

    Non-negative data-driven mapping of structural connections with application to the neonatal brain

    Get PDF
    Mapping connections in the neonatal brain can provide insight into the crucial early stages of neurodevelopment that shape brain organisation and lay the foundations for cognition and behaviour. Diffusion MRI and tractography provide unique opportunities for such explorations, through estimation of white matter bundles and brain connectivity. Atlas-based tractography protocols, i.e. a priori defined sets of masks and logical operations in a template space, have been commonly used in the adult brain to drive such explorations. However, rapid growth and maturation of the brain during early development make it challenging to ensure correspondence and validity of such atlas-based tractography approaches in the developing brain. An alternative can be provided by data-driven methods, which do not depend on predefined regions of interest. Here, we develop a novel data-driven framework to extract white matter bundles and their associated grey matter networks from neonatal tractography data, based on non-negative matrix factorisation that is inherently suited to the non-negative nature of structural connectivity data. We also develop a non-negative dual regression framework to map group-level components to individual subjects. Using in-silico simulations, we evaluate the accuracy of our approach in extracting connectivity components and compare with an alternative data-driven method, independent component analysis. We apply non-negative matrix factorisation to whole-brain connectivity obtained from publicly available datasets from the Developing Human Connectome Project, yielding grey matter components and their corresponding white matter bundles. We assess the validity and interpretability of these components against traditional tractography results and grey matter networks obtained from resting-state fMRI in the same subjects. We subsequently use them to generate a parcellation of the neonatal cortex using data from 323 new-born babies and we assess the robustness and reproducibility of this connectivity-driven parcellation

    A geometric morphometric study on geographical Iranian populations of the pod borer, Helicoverpa armigera (Lepidoptera: Noctuidae)

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    Multivariate analyses of the morphological variation in five geographical populations of the pod borer, Helicoverpa armigera (Hübner), was performed using 15 and 12 landmarks selected from the fore- and hindwings respectively. Using their geometric morphometric characters (26 in the forewings and 20 in the hindwings), 287 and 277 images of fore- and hindwings were made respectively. Analyses of size showed the wings of the females are bigger than those of the males (forewing: F = 3.98, P = 0.047; hindwing: F = 14.62, P = 0.000) on populations tested. The discriminant function analysis (DFA) of fore- and hindwings differentiated five geographical populations with 86.1% and 69.3%, respectively. The multivariate analysis of variance (MANOVA) of shape variables in fore- and hindwings indicated significant differences among populations as well as sexes (at least for one of the shape variables). Sex interaction within the populations was significant in fore- and hindwings, particularly based on the hindwing landmarks. The relative warp analysis (RWA) showed well-supported discrimination between sexes. The results showed significant difference between the sexes and also within the populations

    Variability in gene cassette patterns of class 1 and 2 integrons associated with multi drug resistance patterns in Staphylococcus aureus clinical isolates in Tehran-Iran

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    Background: To investigate antibiotic resistance, the occurrence and distribution of class 1 and 2 integrons in multidrug- resistant Staphylococcus aureus isolates from hospitals in Tehran, Iran. The isolates were examined for susceptibility to antimicrobial agents. The mecA gene, class 1 and 2 integrons were detected by PCR. Integrase positive strains were further analysed for the presence of resistance gene cassettes using specific primers and were sequenced. Results: Among 139S.aureus isolates, 109 (78.4 ) and 112 (80.5 ) strains were considered as multidrug resistant and mecA positive, respectively. Class 1 integrons and internal variable regions were found in 72.6 (101/139) and 97 (98/101) and class 2 integrons and variable regions also in 35.2 (49/139) and 65.3 (32/49) of S.aureus clinical isolates, respectively. Twelve distinct cassette arrays were found, containing genes encoding resistance to β-lactams, aminoglycosides, streptothricin, trimethoprim, chloramphenicol,a putative glucose dehydrogenase precursor and a protein with unknown function. Gene cassette arrays aadB, aadA2 and dhfrA1-sat2-aadA1 were common in S.aureus isolates. We detected a completely new gene cassettes which contained aadB, oxa2, aacA4, orfD-aacA4-catB8, aadB-catB3, orfD-aacA4 and aadB-aadA1-cmlA6 of class 1 and dhfrA1-sat2-aadA1, dhfrA11, dhfrA1-sat2 of class 2 integrons. Conclusions: This is the first study to report carriage of class 1 and 2 integrons and associated gene cassettes among in S.aureus isolates from Iran. © 2015 Mostafa et al
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