518 research outputs found

    Small loop spaces and covering theory of non-homotopically Hausdorff spaces

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    In this paper we devote to spaces that are not homotopically hausdorff and study their covering spaces. We introduce the notion of small covering and prove that every small covering of XX is the universal covering in categorical sense. Also, we introduce the notion of semi-locally small loop space which is the necessary and sufficient condition for existence of universal cover for non-homotopically hausdorff spaces, equivalently existence of small covering spaces. Also, we prove that for semi-locally small loop spaces, XX is a small loop space if and only if every cover of XX is trivial if and only if π1top(X)\pi_1^{top}(X) is an indiscrete topological group.Comment: 7 page

    Spanier spaces and covering theory of non-homotopically path Hausdorff spaces

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    H. Fischer et al. (Topology and its Application, 158 (2011) 397-408.) introduced the Spanier group of a based space (X,x)(X,x) which is denoted by \psp. By a Spanier space we mean a space XX such that \psp=\pi_1(X,x), for every x∈Xx\in X. In this paper, first we give an example of Spanier spaces. Then we study the influence of the Spanier group on covering theory and introduce Spanier coverings which are universal coverings in the categorical sense. Second, we give a necessary and sufficient condition for the existence of Spanier coverings for non-homotopically path Hausdorff spaces. Finally, we study the topological properties of Spanier groups and find out a criteria for the Hausdorffness of topological fundamental groups.Comment: 14 pages, 2 figures. arXiv admin note: text overlap with arXiv:1102.0993 by other author

    On locally 1-connectedness of quotient spaces and its applications to fundamental groups

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    Let XX be a locally 1-connected metric space and A1,A2,...,AnA_1,A_2,...,A_n be connected, locally path connected and compact pairwise disjoint subspaces of XX. In this paper, we show that the quotient space X/(A1,A2,...,An)X/(A_1,A_2,...,A_n) obtained from XX by collapsing each of the sets AiA_i's to a point, is also locally 1-connected. Moreover, we prove that the induced continuous homomorphism of quasitopological fundamental groups is surjective. Finally, we give some applications to find out some properties of the fundamental group of the quotient space X/(A1,A2,...,An)X/(A_1,A_2,...,A_n).Comment: 11 page

    Effects of deoxynivalenol and deepoxy-deoxynivalenol on bovine ovarian theca cell function

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    La mycotoxine dĂ©oxynivalĂ©nol (DON) et son mĂ©tabolite dĂ©Ă©poxy-dĂ©oxynivalenol (DOM-1) ont des effets significatifs sur la modification de la fonction des cellules thĂšcales de l’ovaire bovin. L'objectif de cette Ă©tude Ă©tait d'identifier les diffĂ©rentes voies de signalisation impliquĂ©es dans le mĂ©canisme d'action de DON et DOM-1 par la spectromĂ©trie de masse. MĂ©thodes: Les cellules thĂ©cales de l'ovaire bovin ont Ă©tĂ© rĂ©coltĂ©es Ă  partir des vaches adultes, indĂ©pendamment du stade du cycle Ɠstral, et ont Ă©tĂ© cultivĂ©es Ă  une densitĂ© de 500000 cellules viables dans 1 ml de milieu de McCoy pendant 5 jours. Les cellules ont ensuite Ă©tĂ© traitĂ©es au jour 5 de la culture avec 1 ng/ml de DON ou DOM-1 pendant 30 minutes et des Ă©chantillons cellulaires de protĂ©ins totales ont Ă©tĂ© prĂ©parĂ©s pour spectromĂ©trie de masse. RĂ©sultats: la spectromĂ©trie de masse a montrĂ© que DON et DOM-1 induisent une surexpression simultanĂ©e de ERK1/2, MAPK14 (p38alpha) et MAPK13 (p38delta). La spectromĂ©trie de masse a Ă©galement indiquĂ© que 94 peptides ont Ă©tĂ© surexprimĂ©s tels que GNGT1, EDN1 et YWHAB. Ils rĂ©gulent la plupart des voies de prolifĂ©ration des cellules et sont impliquĂ©s dans la biosynthĂšse des lipides et des glucides. NĂ©anmoins, 255 peptides ont Ă©tĂ© rĂ©gulĂ©s Ă  la baisse, tels que CALR3, PTGES3, RAD21, ACVR2B et TGFBR1 dont leurs activitĂ©s sont principalement l'activation ou la dĂ©sactivation des processus apoptotiques, et le mĂ©tabolisme du glucose et de la choline. Nos rĂ©sultats montrent que DON et DOM-1, Ă  une dose de 1 ng/ml, ont le potentiel de stimuler la surexpression de MAPK distinctes et rĂ©guler nĂ©gativement les voies de signalisation spĂ©cifiques qui stimulent la prolifĂ©ration les cellules de la thĂšque de l’ovaire de bovin.The mycotoxin deoxynivalenol (DON) and its metabolite deepoxy-DOM-1 have significant effects on bovine ovarian theca cell function. The objective of this study was to identify different signaling pathways involved in the mechanism of action of DON and DOM-1 by mass spectrometry. Methods: bovine ovarian theca cells were harvested from adult cows independently of the stage of the estrous cycle, and were cultured at a density of 500000 viable cells in 1 ml McCoy’s medium for 5 days. The cells were then treated on day 5 of culture with 1 ng/mL DON or DOM-1 for 30 minutes and total cell protein was collected for mass spectrometry. Results from mass spectrometry showed that both DON and DOM-1 induce simultaneous upregulation of ERK1/2 , MAPK14 (p38alpha) and MAPK13 (p38delta). Mass spectrometry also indicated that 94 peptides such as GNGT1, EDN1 and YWHAB were upregulated. They mostly regulate cell proliferation pathways and are involved in biosynthesis of lipid and carbohydrates. Nevertheless, 255 peptides such as CALR3, PTGES3, RAD21, ACVR2B and TGFBR1 were downregulated whose activities are mainly activation or deactivation of apoptotic processes, and glucose and choline metabolism. Our findings show that both DON and DOM-1 at least at a low dose (1 ng/ml) have the potential to stimulate upregulation of distinct MAPKs and downregulate specific signaling pathways that stimulate bovine ovarian theca cell proliferation

    Fibrous Dysplasia of the Orbit in a 5-Year-Old Girl

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    Purpose: The aim of the present study was to describe a case oforbital fibrous dysplasia in a very young child.Case report: A 5-year-old girl presented with unilateral, painless,slowly progressive proptosis of the left eye and inferotemporalglobe displacement from about 1 year ago. The visual acuity inboth eyes was 20/20. The general physical examination was normal.Computed tomography (CT scan) revealed thickening and deformityof the orbital walls. Lateral orbitotomy and biopsy were performedand were compatible with fibrous dysplasia.Conclusion:   Craniofacial fibrous dysplasia usually occurs in thesecond decade of life, but it can also rarely present in the earlyyears of life. Therefore, fibrous dysplasia should be considered asa differential diagnosis of proptosis or globe displacement in theearly years of life.Keywords: Fibrous; Dysplasia; Orbit; Child; Iran
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