183 research outputs found

    The standard cohomology of regular Courant algebroids

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    For any regular Courant algebroid EE over a smooth manifold MM with characteristic distribution FF and ample Lie algebroid AEA_E, we prove that there exists a canonical homological vector field on the graded manifold AE[1]βŠ•(TM/F)βˆ—[2]A_E[1] \oplus (TM/F)^\ast[2] such that the associated dg manifold ME\mathcal{M}_E, which we call the minimal model of the Courant algebroid EE, encodes all cohomological data of EE. Thereby, the standard cohomology Hstβ‘βˆ™(E)H^\bullet_{\operatorname{st}}(E) of EE can be identified with the cohomology Hβˆ™(ME)H^\bullet(\mathcal{M}_E) of the function space on ME\mathcal{M}_E. To compute it, we find a natural transgression map [d_T] \colon H^{\bullet}_{\operatorname{CE}}\big(A_E; S^{\diamond}(TM/F[-2])\big) \to H^{\bullet+3}_{\CE}\big(A_E; S^{\diamond-1}(TM/F[-2])\big) from which we construct a spectral sequence which converges to Hstβ‘βˆ™(E)H^\bullet_{\operatorname{st}}(E). Moreover, we give applications to generalized exact Courant algebroids and those arising from regular Lie algebroids .Comment: 41 pages; the main body is rewritten; typos remove

    DIFFERENTIAL RESPONSES OF PHOTOSYSTEM II ACTIVITY TO PHOTOOXIDATION IN RED AND GREEN TISSUES OF AMARANTHUS TRICOLOR LEAVES

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    In order to study the antioxidative potential of amaranthine and its relationships with photoprotection, changes of PS II activity of red and green tissue in the same edible amaranth leaf were compared under photooxidation treatment induced by MV (methy

    Bismuth-doped zinc aluminosilicate glasses and glass-ceramics with ultra-broadband infrared luminescence

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    Abstract Broadband infrared luminescence covering the optical telecommunication wavelength region of O, E and S bands was observed from bismuth-doped zinc aluminosilicate glasses and glass-ceramics. The spectroscopic properties of the glasses and glass-ceramics depend on the thermal-treatment history. With the appearance of gahnite (ZnAl 2 O 4 ) crystalline phase, the fluorescent peak moves to longer wavelength, but the fluorescent intensity decreases. The $1300 nm fluorescence with a FWHM larger than 250 nm and a lifetime longer than 600 ls possesses these optical materials with potential applications in laser devices and broadband amplifiers. The broad infrared luminescence from the bismuth-doped zinc aluminosilicate glasses and glass-ceramics might be from BiO or bismuth clusters rather than from Bi 5+ and Bi 3+

    LRRK2 in Parkinson's disease and dementia with Lewy bodies

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    BACKGROUND: Mutations in LRRK2 encoding leucine-rich repeat kinase 2 are thus far the most frequent genetic cause associated with autosomal dominant and idiopathic Parkinson's disease (PD). To examine whether LRRK2 is directly associated with neuropathology of PD and other related disorders, we analyzed LRRK2 in brains of patients affected by PD and dementia with Lewy bodies (DLB) using highly specific antibodies to LRRK2. RESULTS: We demonstrated that anti-LRRK2 antibodies strongly labelled brainstem and cortical Lewy bodies, the pathological hallmarks of PD and DLB, respectively. In addition, anti-LRRK2 also labelled brain vasculature, axons, and neuronal cell bodies. Interestingly, the immunocytochemical profile of LRRK2 varied with different antibodies depending upon specific antigenic sites along the LRRK2 protein. All anti-LRRK2 antibodies tested that were raised against various regions of LRRK2, were found to be immunoreactive to recombinant LRRK2 on Western blots. However, only the antibodies raised against the N-terminal and C-terminal regions of LRRK2, but not the regions containing folded protein domains, were positive in immunolabeling of Lewy bodies, suggesting a differential exposure of specific antigenic sites of LRRK2 on tissue sections. CONCLUSION: We conclude that LRRK2 is a component of Lewy bodies in both PD and DLB, and therefore plays an important role in the Lewy body formation and disease pathogenesis. Information on the cellular localization of LRRK2 under normal and pathological conditions will deepen our understanding of its functions and molecular pathways relevant to the progression of PD and related disorders

    Detection of femtomolar level osteosarcoma-related gene via a chronocoulometric DNA biosensor based on nanostructure gold electrode

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    In this paper, a sensitive chronocoulometric deoxyribonucleic acid (DNA) biosensor based on a nanostructure gold electrode was fabricated for detection of the femtomolar level survivin gene which was correlated with osteosarcoma by using hexaamine-ruthenium III complexes, [Ru(NH3)6]3+, as the electrochemical indicator. The effect of different frequencies on the real surface area of the nanostructure gold electrode obtained by repetitive square-wave oxidation reduction cycle was investigated. At the optimal frequency of 8000 Hz, the real surface of the developed nanostructure gold electrode was about 42.5 times compared with that of the bare planar gold electrode. The capture probe DNA was immobilized on the nanostructure gold electrode and hybridized with target DNA. Electrochemical signals of hexaamine-ruthenium III bound to the anionic phosphate of DNA strands via electrostatic interactions were measured by chronocoulometry before and after hybridization. The increase of the charges of hexaamine-ruthenium III was observed upon hybridization of the probe with target DNA. Results indicate that this DNA biosensor could detect the femtomole (fM) concentration of the DNA target quantitatively in the range of 50 fM to 250 fM; the detection limit of this DNA biosensor was 5.6 fM (signal to noise = 3). This new biosensor exhibits excellent sensitivity and selectivity and has been used for an assay of polymerase chain reaction (PCR) with a satisfactory result
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