Determination of structural similarity by quantitative comparisons of Wiswesser Line Notation entries

1990 ◽  
Vol 30 (1) ◽  
pp. 73-80 ◽  
Author(s):  
Thomas F. Kaltenbach ◽  
Gary W. Small
Keyword(s):  
Structural Similarity

Determination of the Number of Conserved Chromosomal Segments Between Species

Genetics ◽  
2001 ◽  
Vol 157 (3) ◽  
pp. 1387-1395 ◽  
Author(s):  
Sudhir Kumar ◽  
Sudhindra R Gadagkar ◽  
Alan Filipski ◽  
Xun Gu
Keyword(s):  
Statistical Approach ◽  
Common Ancestor ◽  
Chromosomal Rearrangements ◽  
Structural Similarity ◽  
The Other ◽  
Segment Length ◽  
Human Genomes ◽  
Genomic Divergence ◽  
Human And Mouse

AbstractGenomic divergence between species can be quantified in terms of the number of chromosomal rearrangements that have occurred in the respective genomes following their divergence from a common ancestor. These rearrangements disrupt the structural similarity between genomes, with each rearrangement producing additional, albeit shorter, conserved segments. Here we propose a simple statistical approach on the basis of the distribution of the number of markers in contiguous sets of autosomal markers (CSAMs) to estimate the number of conserved segments. CSAM identification requires information on the relative locations of orthologous markers in one genome and only the chromosome number on which each marker resides in the other genome. We propose a simple mathematical model that can account for the effect of the nonuniformity of the breakpoints and markers on the observed distribution of the number of markers in different conserved segments. Computer simulations show that the number of CSAMs increases linearly with the number of chromosomal rearrangements under a variety of conditions. Using the CSAM approach, the estimate of the number of conserved segments between human and mouse genomes is 529 ± 84, with a mean conserved segment length of 2.8 cM. This length is <40% of that currently accepted for human and mouse genomes. This means that the mouse and human genomes have diverged at a rate of ∼1.15 rearrangements per million years. By contrast, mouse and rat are diverging at a rate of only ∼0.74 rearrangements per million years.

scholarly journals Phytoestrogens in bovine plasma and milk – LC-MS/MS analysis

2010 ◽  
Vol 28 (No. 4) ◽  
pp. 264-274 ◽  
Author(s):  
A. Krajčová ◽  
V. Schulzová ◽  
J. Lojza ◽  
L. Křížová ◽  
J. Hajšlová
Keyword(s):  
Biological Fluids ◽  
Structural Similarity ◽  
Biologically Active ◽  
Feeding Experiment ◽  
Plant Metabolites ◽  
Alternative Source ◽  
Biological Responses ◽  
Bovine Plasma ◽  
The Relationship

Phytoestrogens belong to a group of polyphenolic plant metabolites which induce biological responses, based on their structural similarity to 17β-estradiol. In order to investigate the relationship between the levels of these biologically active compounds and beneficial health effects, it is neccesary to quantify accurately their levels in foods and biological fluids. In this study, HPLC-MS/MS method for the determination of isoflavones genistein, daidzein, and estrogenic metabolite-equol in bovine plasma and milk was optimised and validated. The method allowed low limits of detection: 5, 2.5 and 0.5 ng/ml for genistein, daidzein and equol, respectively, thus enabling to determine the effect of phytoestrogen-rich diet on the concentration of isoflavones and the metabolite in biological fluids of cows. The feeding experiment, carried out with four dairy cows, showed that a soy-based diet significantly increased both plasma and milk contents of biologically potent equol, therefore, the latter commodity could be an alternative source of this estrogenic metabolite, namely for the consumers who are not capable to convert it from the isoflavone precursors consumed in the diet.

Comparison of the neuralized genes of Drosophila virilis and D. melanogaster

Genome ◽  
1994 ◽  
Vol 37 (5) ◽  
pp. 840-847 ◽  
Author(s):  
Lily Zhou ◽  
Gabrielle L. Boulianne
Keyword(s):  
Drosophila Melanogaster ◽  
Cell Fate ◽  
Structural Similarity ◽  
Drosophila Virilis ◽  
Interspecific Comparison ◽  
Functional Regions ◽  
Embryonic Nervous System ◽  
Localization Signal ◽  
Evolutionary Comparison

The neurogenic gene neuralized of Drosophila melanogaster is thought to play a role in the determination of cell fate in the embryonic nervous system as well as other tissues during development. To determine which sequences within the neuralized gene encode functionally important domains, we have initiated an interspecific comparison of the neuralized gene of D. virilis and D. melanogaster. In this study we show that several motifs that we have previously identified in the neuralized protein of D. melanogaster are conserved in D. virilis. These include a putative nuclear localization signal, a homeodomain similarity region, and a zinc finger motif. In contrast, a helix-turn-helix motif with structural similarity to those identified as DNA-binding regions of bacterial repressors is deleted. These results demonstrate that it is possible to identify key functional regions of the neuralized protein by an interspecific comparison.Key words: Drosophila melanogaster, Drosophila virilis, neuralized, nucleotide sequence, evolutionary comparison.

scholarly journals A microtubule RELION-based pipeline for cryo-EM image processing

2019 ◽  
Author(s):  
Alexander D. Cook ◽  
Szymon W. Manka ◽  
Su Wang ◽  
Carolyn A. Moores ◽  
Joseph Atherton
Keyword(s):  
Electron Microscopy ◽  
Image Processing ◽  
Structural Similarity ◽  
Geometric Lattice ◽  
Contrast Transfer Function ◽  
Biologically Relevant ◽  
Cryo Electron Microscopy

AbstractMicrotubules are polar filaments built from αβ-tubulin heterodimers that exhibit a range of architectures in vitro and in vivo. Tubulin heterodimers are arranged helically in the microtubule wall but many physiologically relevant architectures exhibit a break in helical symmetry known as the seam. Noisy 2D cryo-electron microscopy projection images of pseudo-helical microtubules therefore depict distinct but highly similar views owing to the high structural similarity of α- and β-tubulin. The determination of the αβ-tubulin register and seam location during image processing is essential for alignment accuracy that enables determination of biologically relevant structures. Here we present a pipeline designed for image processing and high-resolution reconstruction of cryo-electron microscopy microtubule datasets, based in the popular and user-friendly RELION image-processing package, Microtubule RELION-based Pipeline (MiRP). The pipeline uses a combination of supervised classification and prior knowledge about geometric lattice constraints in microtubules to accurately determine microtubule architecture and seam location. The presented method is fast and semi-automated, producing near-atomic resolution reconstructions with test datasets that contain a range of microtubule architectures and binding proteins.AbbreviationsMiRP, Microtubule RELION-based Pipeline; cryo-EM, cryo-electron microscopy; MT, microtubule; CTF, contrast transfer function; PF, protofilament.

scholarly journals Analytical applications of electrode sensitive to labetalol in pharmaceuticals

2003 ◽  
Vol 1 (3) ◽  
pp. 242-259 ◽  
Author(s):  
Ewa Gorodkiewicz ◽  
Paweł Falkowski ◽  
Anna Sankiewicz ◽  
Zbigniew Figaszewski
Keyword(s):  
Liquid Membrane ◽  
Inorganic Ions ◽  
Structural Similarity ◽  
Protonated Form ◽  
Direct Potentiometry ◽  
Analytical Properties ◽  
Nernstian Slope ◽  
Ph Range ◽  
Influence Of Ph

AbstractThe analytical properties of an ion-selective electrode sensitive to labetalol with a liquid membrane, based on ion-pair complexes with sodium tetraphenylborate (TPB-Na+) are described. The studied electrode can be used for the determination of labetalol hydrochloride as a protonated form of labetalol in pharmaceuticals. The calibration curve, e.g. EMF=f(pCLabHCl) is linear in the range from 10−5 to 10−2 mol L−1 with a correlation coefficient of 0.9992 and slope of 61.13 mV/decade, which is close to the Nernstian slope. The detection limit of the examined electrode is 7.20×10−6 mol L−1. The influence of pH of the tested solutions on the formulation of the electrode is not as considerable since the electrode works correctly in the pH range 3.0–8.0. The main attributes of the developed electrode are: stability, good reproducibility of EMF and short response time, close to 30 seconds depending on labetalol concentration in the solution. The electrode shows good selectivity for many inorganic ions. The selectivity for drug cations is weaker due to the structural similarity of the interfering cations to labetalol. The results of labetalol determination using direct potentiometry in drugs such as Pressocard (Polpharma) and Trandate (GlaxoWellcome) were compatible with the quantity of labetalol declared by the manufacturer, and with parallel UV spectrophotometric and HPLC determinations.

Galactic orbits of stars

1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley
Keyword(s):  
Globular Cluster ◽  
Potential Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Variable Stars ◽  
The Sun ◽  
Proper Motions ◽  
Rr Lyrae ◽  
The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

Distance to SN 1987A and the LMC

1999 ◽  
Vol 190 ◽  
pp. 549-554
Author(s):  
Nino Panagia
Keyword(s):  
Angular Size ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Distance Modulus ◽  
Absolute Size ◽  
Sn 1987A

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.

International determination of the total motion of the pole

1961 ◽  
Vol 13 ◽  
pp. 29-41
Author(s):  
Wm. Markowitz
Keyword(s):  
Secular Motion ◽  
The Future

A symposium on the future of the International Latitude Service (I. L. S.) is to be held in Helsinki in July 1960. My report for the symposium consists of two parts. Part I, denoded (Mk I) was published [1] earlier in 1960 under the title “Latitude and Longitude, and the Secular Motion of the Pole”. Part II is the present paper, denoded (Mk II).

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