A phenolic–taxometric study of Medicago (Leguminosae)

1982 ◽  
Vol 60 (12) ◽  
pp. 2477-2495 ◽  
Author(s):  
D. Classen ◽  
C. Nozzolillo ◽  
E. Small

Phenolics from dried leaf tissue of 47 species of Medicago were examined using two-dimensional chromatography on polyamide plates. A few samples from the closely related genera Melilotus and Trigonella were also studied. Compounds tentatively identified as cyanidin, quercetin, kaempferol, luteolin, apigenin, chrysoeriol, tricin, and coumestrol were found. Proanthocyanidins were not detected in the leaf tissue of any of the species. Apigenin was found in all species of Medicago except M. cretacea but not in the one species of Melilotus or the two of Trigonella studied. Two additional compounds as yet unidentified were also restricted to Medicago. All of the phenolics were detected as aglycones with the possible exceptions of glucuronides and C-glycosides which are strongly resistant to hydrolysis. Data for the phenolic compounds were subjected to numerical taxonomic analysis. The single species of Melilotus and the two species of Trigonella were dramatically different from Medicago in their phenolic composition. A number of controversial species placed in Medicago by some taxonomists, and in Trigonella by others, proved to have phenolic profiles much like Medicago and quite unlike the species of Trigonella examined. The annual species comprising subgenus Spirocarpos, which are morphologically distinct from the remaining species of Medicago, were not clearly distinguishable from the other species collectively on the basis of phenolic chemistry. However, within subgenus Spirocarpos the most sharply distinguished subgroup on morphological criteria, section Pachyspirae, tended to be different chemically from the remaining species of the subgenus. When the species of Medicago except for subgenus Spirocarpos were analysed separately, it was found that the two major phylads of these tended to be distinguishable chemically. These included a group of perennials (subgenus Medicago section Falcago) and a group of peculiar species (subgenus Orbicularia) tending morphologically towards the genus Trigonella). Appreciable intraspecific diversity was found for phenolic chemistry but significantly less than interspecific variation. In a few cases species which are quite similar morphologically diverged chemically, most notably the two species of subgenus Lupularia.

1979 ◽  
Author(s):  
R. Kotitschke ◽  
J. Scharrer

F.VIII R:Ag was determined by quantitative immunelectrophoresis (I.E.) with a prefabricated system. The prefabricated system consists of a monospecific f.VIII rabbit antiserum in agarose on a plastic plate for the one and two dimensional immunelectrophoresis. The lognormal distribution of the f.VIII R:Ag concentration in the normal population was confirmed (for n=70 the f.VIII R:Ag in % of normal is = 95.4 ± 31.9). Among the normal population there was no significant difference between blood donors (one blood donation in 8 weeks; for n=43 the f.VIII R:Ag in % of normal is = 95.9 ± 34.0) and non blood donors (n=27;f.VIII R:Ag = 94.6 ± 28.4 %). The f.VIII R:Ag concentration in acute hepatitis B ranged from normal to raised values (for n=10, a factor of 1.8 times of normal was found) and was normal again after health recovery (n=10, the factor was 1.0). in chronic hepatitis the f.VIII R:Ag concentration was raised in the majority of the cases (for n=10, the factor was 3.8). Out of 22 carrier sera 20 showed reduced, 2 elevated levels of the f.VIII R:Ag concentration. in 5 sera no f.VIII R:Ag could be demonstrated. The f.VIII R:Ag concentration was normal for n=10, reduced for n=20 and elevated for n=6 in non A-non B hepatitis (n=36). Contrary to results found in the literature no difference in the electrophoretic mobility of the f.VIII R:Ag was found between hepatitis patients sera and normal sera.


Author(s):  
Geoffrey Hellman ◽  
Stewart Shapiro

This chapter develops a Euclidean, two-dimensional, regions-based theory. As with the semi-Aristotelian account in Chapter 2, the goal here is to recover the now orthodox Dedekind–Cantor continuum on a point-free basis. The chapter derives the Archimedean property for a class of readily postulated orientations of certain special regions, what are called “generalized quadrilaterals” (intended as parallelograms), by which the entire space is covered. Then the chapter generalizes this to arbitrary orientations, and then establishes an isomorphism between the space and the usual point-based one. As in the one-dimensional case, this is done on the basis of axioms which contain no explicit “extremal clause”, and we have no axiom of induction other than ordinary numerical (mathematical) induction.


Mathematics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 531
Author(s):  
Pedro Pablo Ortega Palencia ◽  
Ruben Dario Ortiz Ortiz ◽  
Ana Magnolia Marin Ramirez

In this article, a simple expression for the center of mass of a system of material points in a two-dimensional surface of Gaussian constant negative curvature is given. By using the basic techniques of geometry, we obtained an expression in intrinsic coordinates, and we showed how this extends the definition for the Euclidean case. The argument is constructive and serves to define the center of mass of a system of particles on the one-dimensional hyperbolic sphere LR1.


2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Ashoke Sen

Abstract In a recent paper, Balthazar, Rodriguez and Yin found remarkable agreement between the one instanton contribution to the scattering amplitudes of two dimensional string theory and those in the matrix model to the first subleading order. The comparison was carried out numerically by analytically continuing the external energies to imaginary values, since for real energies the string theory result diverges. We use insights from string field theory to give finite expressions for the string theory amplitudes for real energies. We also show analytically that the imaginary parts of the string theory amplitudes computed this way reproduce the full matrix model results for general scattering amplitudes involving multiple closed strings.


2002 ◽  
Vol 12 (03n04) ◽  
pp. 341-358
Author(s):  
KRISHNA M. KAVI ◽  
DINESH P. MEHTA

This paper presents two algorithms for mutual exclusion on optical bus architectures including the folded one-dimensional bus, the one-dimensional array with pipelined buses (1D APPB), and the two-dimensional array with pipelined buses (2D APPB). The first algorithm guarantees mutual exclusion, while the second guarantees both mutual exclusion and fairness. Both algorithms exploit the predictability of propagation delays in optical buses.


2007 ◽  
Vol 21 (02n03) ◽  
pp. 139-154 ◽  
Author(s):  
J. H. ASAD

A first-order differential equation of Green's function, at the origin G(0), for the one-dimensional lattice is derived by simple recurrence relation. Green's function at site (m) is then calculated in terms of G(0). A simple recurrence relation connecting the lattice Green's function at the site (m, n) and the first derivative of the lattice Green's function at the site (m ± 1, n) is presented for the two-dimensional lattice, a differential equation of second order in G(0, 0) is obtained. By making use of the latter recurrence relation, lattice Green's function at an arbitrary site is obtained in closed form. Finally, the phase shift and scattering cross-section are evaluated analytically and numerically for one- and two-impurities.


1994 ◽  
Vol 262 (2) ◽  
pp. 173-184 ◽  
Author(s):  
Tadasu Urashima ◽  
William A. Bubb ◽  
Michael Messer ◽  
Yuhnagi Tsuji ◽  
Yasuko Taneda

Author(s):  
Yuri M. Laevsky ◽  
Tatyana A. Nosova

AbstractA multidimensional model of filtration gas combustion is presented. The model is based on the system of conservation laws of ‘temperature – heat flow’, ‘mass–diffusive flow’ types with introducing the concept of total enthalpy flow. Results of numerical experiments are presented for the one- and two-dimensional problems for different conditions and parameters.


Author(s):  
Bharti bharti ◽  
Debabrata Deb

We use molecular dynamics simulations to investigate the ordering phenomena in two-dimensional (2D) liquid crystals over the one-dimensional periodic substrate (1DPS). We have used Gay-Berne (GB) potential to model the...


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