916 research outputs found

    Maximal left ideals of the Banach algebra of bounded operators on a Banach space

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    We address the following two questions regarding the maximal left ideals of the Banach algebra B(E)\mathscr{B}(E) of bounded operators acting on an infinite-dimensional Banach pace EE: (Q1) Does B(E)\mathscr{B}(E) always contain a maximal left ideal which is not finitely generated? (Q2) Is every finitely-generated, maximal left ideal of B(E)\mathscr{B}(E) necessarily of the form \{T\in\mathscr{B}(E): Tx = 0\} (*) for some non-zero xEx\in E? Since the two-sided ideal F(E)\mathscr{F}(E) of finite-rank operators is not contained in any of the maximal left ideals given by (*), a positive answer to the second question would imply a positive answer to the first. Our main results are: (i) Question (Q1) has a positive answer for most (possibly all) infinite-dimensional Banach spaces; (ii) Question (Q2) has a positive answer if and only if no finitely-generated, maximal left ideal of B(E)\mathscr{B}(E) contains F(E)\mathscr{F}(E); (iii) the answer to Question (Q2) is positive for many, but not all, Banach spaces.Comment: to appear in Studia Mathematic

    Impact of the density of the mould powder on thickness of the layer of liquid slag in the continuous caster mould

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    The paper presents results of measurements of the thickness of liquid slag layer in concast mould for pulverized, granulated or formed mould powder. The thickest layer of liquid slag was obtained for formed powders

    Development of Green Pavement for Reducing Oxides of Nitrogen (NOx) in the Ambient Air

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    The transportation sector is the biggest contributor to air pollution in Indonesia, especially in metropolitan cities. Gases such as oxides of nitrogen (NOx) are produced during the combustion of fossil fuels in the internal combustion of vehicle engines. Oxides of nitrogen such as nitric oxide (NO) and nitrogen dioxide (NO2) are important air pollutants, because they cause significant harm to human health and play an important role in being precursors of other dangerous pollutants such as photochemical smog. One of the simple ways to reduce NOx concentrations is utilizing a catalytic process involving UV light and semiconductor particles such as TiO2. Illuminated TiO2 UV light is capable of producing an electron (e-) and hole (h-) pair, which initiates a chemical reaction that alters the NOx to become NO3- or NO2-. A field scale paving block reactor coated with TiO2 placed by the roadside was exposed to UV light using various exposure times. The results showed that the sample with a composition of 200 g/m2 TiO2 was capable of adsorbing NOx gas at an average rate of 0.0046 mg/m2/minute. Additional costs due to TiO2 coating for every square meter of paving are IDR 13,180

    3-manifold invariants and periodicity of homology spheres

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    We show how the periodicity of a homology sphere is reflected in the Reshetikhin-Turaev-Witten invariants of the manifold. These yield a criterion for the periodicity of a homology sphere.Comment: Published by Algebraic and Geometric Topology at http://www.maths.warwick.ac.uk/agt/AGTVol2/agt-2-34.abs.htm

    Staphylococcus pseudintermedius Sbi paralogs inhibit complement and bind IgM, IgG Fc and Fab

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    The success of staphylococci as pathogens has been attributed, in part, to their ability to evade their hosts’ immune systems. Although the proteins involved in evasion have been extensively studied in staphylococci affecting humans little characterization has been done with Staphylococcus pseudintermedius, an important cause of pyoderma in dogs. Staphylococcus aureus binder of immunoglobulin (Sbi) interferes with innate immune recognition by interacting with multiple host proteins. In this study, a S. pseudintermedius gene that shares 38% similarity to S. aureus Sbi was cloned from S. pseudintermedius strains representative of major clonal lineages bearing two paralogs of the protein. Binding of immunoglobulins and Fab and Fc fragments as well as interaction with complement was measured. S. pseudintermedius Sbi protein bound IgG from multiple species and canine complement C3, neutralized complement activity and bound to canine IgM and B cells. Evidence from this work suggests Sbi may play an important role in S. pseudintermedius immune evasion

    Prominin-1+/CD133+ bone marrow-derived heart-resident cells suppress experimental autoimmune myocarditis

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    AIMS: Experimental autoimmune myocarditis (EAM) is a CD4(+) T cell-mediated mouse model of inflammatory heart disease. Tissue-resident bone marrow-derived cells adopt different cellular phenotypes depending on the local milieu. We expanded a specific population of bone marrow-derived prominin-1-expressing progenitor cells (PPC) from healthy heart tissue, analysed their plasticity, and evaluated their capacity to protect mice from EAM and heart failure. METHODS AND RESULTS: PPC were expanded from healthy mouse hearts. Analysis of CD45.1/CD45.2 chimera mice confirmed bone marrow origin of PPC. Depending on in vitro culture conditions, PPC differentiated into macrophages, dendritic cells, or cardiomyocyte-like cells. In vivo, PPC acquired a cardiac phenotype after direct injection into healthy hearts. Intravenous injection of PPC into myosin alpha heavy chain/complete Freund's adjuvant (MyHC-alpha/CFA)-immunized BALB/c mice resulted in heart-specific homing and differentiation into the macrophage phenotype. Histology revealed reduced severity scores for PPC-treated mice compared with control animals [treated with phosphate-buffered saline (PBS) or crude bone marrow at day 21 after MyHC-alpha/CFA immunization]. Echocardiography showed preserved fractional shortening and velocity of circumferential shortening in PPC but not PBS-treated MyHC-alpha/CFA-immunized mice. In vitro and in vivo data suggested that interferon-gamma signalling on PPC was critical for nitric oxide-mediated suppression of heart-specific CD4(+) T cells. Accordingly, PPC from interferon-gamma receptor-deficient mice failed to protect MyHC-alpha/CFA-immunized mice from EAM. CONCLUSION: Prominin-1-expressing, heart-resident, bone marrow-derived cells combine high plasticity, T cell-suppressing capacity, and anti-inflammatory in vivo effect

    Innovation in metallurgical waste management

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    In the paper was presented innovative solutions of sludge and dust management generated by metallurgical enterprises. These solutions are as follows: usage of steelmaking dust in production of decorative glassware and deoiling of metallurgical sludge useful in producing of iron-bearing briquette for electric arc furnaces (EAF). The influence of the aforementioned technologies on the environment was also discussed
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