2,939 research outputs found

    Trichome Development in \u3ci\u3eArabidopsis thaliana\u3c/i\u3e. II. lsolation and Complementation of the \u3ci\u3eGLABROUS1\u3c/i\u3e Gene

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    We are using the formation of trichomes in Arabidopsis thaliana as a model system to study gene expression during cellular differentiation. To initiate the molecular characterization of this system, we tagged and isolated a gene that is specifically required for the development of the specialized trichome cell. We confirmed the identity of this gene, GLABROUS1 (GL1), by complementation. These results demonstrate that a crucial gene in a plant developmental pathway can be successfully identified by complementation

    Progress toward a Soft X-ray Polarimeter

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    We are developing instrumentation for a telescope design capable of measuring linear X-ray polarization over a broad-band using conventional spectroscopic optics. Multilayer-coated mirrors are key to this approach, being used as Bragg reflectors at the Brewster angle. By laterally grading the multilayer mirrors and matching to the dispersion of a spectrometer, one may take advantage of high multilayer reflectivities and achieve modulation factors over 50% over the entire 0.2-0.8 keV band. We present progress on laboratory work to demonstrate the capabilities of an existing laterally graded multilayer coated mirror pair. We also present plans for a suborbital rocket experiment designed to detect a polarization level of 12-17% for an active galactic nucleus in the 0.1-1.0 keV band.Comment: 11 pages, 12 figures, to appear in the proceedings of the SPIE, volume 8861, on Optics for EUV, X-Ray, and Gamma-Ray Astronom

    Stereochemical control of the DNA binding affinity, sequence specificity, and orientation preference of chiral hairpin polyamides in the minor groove

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    Three-ring polyamides containing pyrrole (Py) and imidazole (Im) amino acids covalently coupled by γ-aminobutyric acid (γ) form six-ring hairpins that recognize five-base-pair sequences in the minor groove of DNA. Selective chiral substitution of the ``gamma-turn'' enhances the properties of polyamide hairpins with regard to DNA affinity and sequence specificity. Polyamides of core sequence composition ImPyPy-γ-PyPyPy which differ by selective stereochemical substitution of the prochiral alpha-position in the γ-turn were prepared. The DNA binding properties of two enantiomeric polyamides were analyzed by footprinting and affinity cleavage on a DNA fragment containing two match sites (5'-TGTTA-3' and 5'-ACATT-3') and one 5'-TGTCA-3' mismatch site. Quantitative footprint titrations demonstrate that replacement of γ-aminobutyric acid by (R)-2,4-diaminobutyric acid enhances DNA binding affinity for the 5'-TGTTA-3' match site 13-fold (K_a = 3.8 x 10^9 M-1). The enhanced affinity is achieved without a compromise in sequence selectivity, which in fact increases and is found to be 100-fold higher relative to binding at a single base pair mismatch sequence, 5'-TGTCA-3'. An (S)-2,4-diaminobutyric acid linked hairpin binds with 170-fold reduced affinity relative to the R-enantiomer and only 5-fold sequence specificity versus a 5'-ACATT-3' reversed orientation site. These effects are modulated by acetylation of the chiral amine substituents. This study identifies structural elements which should facilitate the design of new hairpin polyamides with improved DNA binding affinity, sequence specificity, and orientational selectivity

    A survey of X-ray emission from 100 kpc radio jets

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    We have completed a Chandra snapshot survey of 54 radio jets that are extended on arcsec scales. These are associated with flat spectrum radio quasars spanning a redshift range z=0.3 to 2.1. X-ray emission is detected from the jet of approximately 60% of the sample objects. We assume minimum energy and apply conditions consistent with the original Felten-Morrison calculations in order to estimate the Lorentz factors and the apparent Doppler factors. This allows estimates of the enthalpy fluxes, which turn out to be comparable to the radiative luminosities.Comment: Conference Proceedings IAU Symposium No. 313, Extragalactic jets from every angle, pp. 219-224, 4 figure

    Pelaksanaan Fungsi Aparat Pengawas Intern Pemerintah (Apip) Untuk Menunjang Tingkat Kewajaran Laporan Keuangan Pemerintah Kota Manado

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    Internal Audit is the whole process of audit activities, the Review, evaluation, monitoring and supervisory activities other against the implementation of tasks and functions of the organization in order to provide reasonable assurance that the activities have been carried out in accordance with the benchmarks that have been set effectively and efficiently for the benefit of the leadership to Realize good governance.Accountability and transparency in the new government could be achieved if all levels of leadership controlling activities on the overall activities in their respective agencies . Internal control system ( SPI ) is a process that is integral to the actions and activities carried out continuously by the management and all employees to provide reasonable assurance on the achievement of organizational goals through effective and efficient , the reliability of financial reporting , the safeguarding of state assets, and compliance with legislation. To strengthen and support the effectiveness of internal control over the SPI made ​​implementation of tasks and functions of government agencies including state audits carried out by the internal control official Government ( APIP ) .The auditor\u27s responsibility to detect fraud or irregularity embodied in the planning and execution to obtain reasonable assurance about whether the financial statements have been prepared in accordance with established standards.The purpose of this study was to analyze the functions of Government Internal Supervisory Apparatus (APIP) / Internal Auditor in supporting reasonable levels of Local Government Finance Report Manado City. Respondents were selected are few skilled examiner at the office of the Inspectorate of Manado. Approach Using Qualitative methods Ethnography.APIP functions that work well to prevent fraud , to produce valuable output to be input to the external auditor , the executive and the legislature to improve financial management and accountability in the area of ​​the future . Eksternal Auditor may use the results from the monitoring APIP mainly reviews the financial statements of the government , supporting the management of local government in implementing the recommendations and improvements Internal control system . APIP professional and independent encourage increased transparency and accountability in financial management to improve the fairness of the financial statements
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