Problems in botany, by W. L. Eikenberry.

Eikenberry, W. L.

doi:10.5962/bhl.title.20944

Cited by 5 publications

(5 citation statements)

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“…The sucrose was purified essentially as described by Eikenberry e t a / . [29]. It was stirred with 1 g/l bentonite (Roth, West Germany) to remove any ribonuclease contamination, and passed over a column of Dowex 1 (Serva, Heidelberg) to remove metal ions.…”

Section: Prepurution Of 16-s R N a And Its Complex With Protein S4mentioning

confidence: 99%

Small-Angle X-Ray Studies on the Structure of 16-S Ribosomal RNA and of a Complex of Ribosomal Protein S4 and 16-S Ribosomal RNA from Escherichia coli

Folkhard¹,

Pilz²,

Kratky³

et al. 1975

Eur J Biochem

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1 6 4 ribosomal RNA and a complex of ribosomal protein S4 and 1 6 4 rRNA were studied in solution by small-angle X-ray scattering. Concentration series of the 16-S rRNA and the S4 . 16-SrRNA complex were measured in 37.5 mM Tris-HC1 buffer pH 7.4 at 5 "C.The following data were determined. The radii of gyration for the 16-S rRNA and S4 . 16-S-rRNA complex were R = 17.6 f 0.4 nm and 17.5 L 0.6 nm, respectively. The two respective values of the radii of gyration of the cross-section were Rq,l = 8.42 f 0.1 nm and 8.33 & 0.3nm, and R4,2 = 0.988 -t 0.03nm and 0.996 -t 0.03nm. The largest diameters of the 16-S RNA and S4 . 16-S-RNA complex were L = 61.8 & 1 nm and 60.0 1 nm, respectively. Volumes of V = 1570 f 60 nm3 were found for both particles. In the Tris buffer used, no significant differences were found between the scattering curves of 16-S rRNA and the S4 . 16-S-rRNA complex.A model equivalent in scattering properties to the RNA and complex is a flat elliptical cylinder with the following dimensions : large axis 61.7 nm, small axis 35.4 nm and height 2 nm. The theoretical scattering curve fits the experimental one as long as the shape of the measured curve is due only to the overall shape of the particle. A model equivalent in scattering over the whole measured angular range is one built up from a large number of spheres that simulate the known substructure of the RNA. The outer dimensions of this model correspond to those of the flat elliptical cylinder.16-S rRNA constitutes 60 -65 % dry weight of the 30-S subunit of the Escherichia coli ribosome. It forms a framework for the assembly of 21 different proteins [1,2]. The primary and secondary structure of 16-S rRNA have been extensively studied [3]. Investigations on the secondary structure of rRNA in solution and within the 30-S subunit indicate that it is unchanged. The main characteristic feature of this secondary structure is that about two thirds of the nucleotides are hydrogen-bonded between RNA strands that are antiparallel, resulting in a number of short hairpin-like double-helical regions of maximum length 7 nm [4-91.Although several studies have been performed on the shape and size of ribosomes and their subunits [lo-161, similar studies have not been performed on the 1 6 3 RNA. In the work described here we have determined by small-angle X-ray scattering some important structural parameters for the 16-S RNA. For the first investigations relatively low salt conditions were selected sufficient to maintain the secondary

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Section: Prepurution Of 16-s R N a And Its Complex With Protein S4mentioning

confidence: 99%

Small-Angle X-Ray Studies on the Structure of 16-S Ribosomal RNA and of a Complex of Ribosomal Protein S4 and 16-S Ribosomal RNA from Escherichia coli

Folkhard¹,

Pilz²,

Kratky³

et al. 1975

Eur J Biochem

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“…OPA will be commissioned and take first light at San Diego State University's Mount Laguna Observatory in southern California. OPA is the prototype of what will eventually be a larger PolyOculus array equivalent to a 5-m (or potentially larger) telescope described in the PolyOculus white papers [1,2]. OPA will have all seven telescopes mounted together in an enclosure with proper separation to avoid mechanical collisions.…”

Section: Opa Instrument Updatesmentioning

confidence: 99%

OPA! The Original PolyOculus Array: a status update

Moraitis,

Eikenberry,

Law

et al. 2023

UV/Optical/IR Space Telescopes and Instruments: Innovative Technologies and Concepts XI

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The PolyOculus technology, developed by CREOL's Astrophonics group, creates a large-area-equivalent telescope using fiber optics and a photonic lantern to link several semi-autonomous, small, inexpensive, commercial-off-theshelf telescopes. The Original PolyOculus Array, OPA, will use seven, Celestron 11" telescopes with iOptron centralbalanced equatorial mounts (CEM 70) to create a ~0.75m equivalent optical telescope for spectroscopic follow up observations of astronomical events. This telescope array will include 7 acquisition and guiding systems (one per telescope) to appropriately center and finely focus objects in the telescopes' field of view along with an atmospheric dispersion corrector for each unit. That light will then be sent through single, multimode, optical fibers (one fiber per telescope) and to a photonic lantern where the light from all seven telescopes will be combined then sent to a spectrograph. The photonic lantern has demonstrated over 91% efficiency in combined optical light. The Original PolyOculus Array will be commissioned and operated at Mount Laguna Observatory in southern California. OPA will be the prototype to an eventual, more numerous PolyOculus driven array and other future PolyOculus arrays with different applications.

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“…Since the absolute K band magnitudes of the extrinsic S stars are about -5.7 (van Eck et al 1998), they should have apparent magnitudes of roughly 14 at the distance of the Galactic Center, assuming a distance of 8 kpc, and 5 magnitudes of extinction -these sources should be detectable as S stars in surveys of the Galactic Center, e.g. with FLAMINGOS-2 (Eikenberry 2008).…”

Section: Following a Suggestion Bymentioning

confidence: 99%

Destruction of wide binary stars in low-mass elliptical galaxies: implications for initial mass function estimates

Maccarone¹

2014

Monthly Notices of the Royal Astronomical Society: Letters

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We discuss the effects of destruction of wide binaries in the nuclei of the lower mass giant elliptical galaxies. We show that the numbers of barium stars and extrinsic S stars should be dramatically reduced in these galaxies compared to what is seen in the largest elliptical galaxies. Given that the extrinsic S stars show strong Wing-Ford band and Na I D absorption, we argue that the recent claims of different initial mass functions from the most massive elliptical galaxies versus lower mass ellipticals may be the result of extrinsic S stars, rather than bottom-heavy initial mass function.

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Problems in botany, by W. L. Eikenberry.

Cited by 5 publications

References 0 publications

Small-Angle X-Ray Studies on the Structure of 16-S Ribosomal RNA and of a Complex of Ribosomal Protein S4 and 16-S Ribosomal RNA from Escherichia coli

Small-Angle X-Ray Studies on the Structure of 16-S Ribosomal RNA and of a Complex of Ribosomal Protein S4 and 16-S Ribosomal RNA from Escherichia coli

OPA! The Original PolyOculus Array: a status update

Destruction of wide binary stars in low-mass elliptical galaxies: implications for initial mass function estimates

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