Changes in leucyl, seryl, and tyrosyl tRNAs in aging soybean cotyledons

1974 ◽  
Vol 52 (12) ◽  
pp. 2499-2504 ◽  
Author(s):  
D. T. N. Pillay ◽  
Joe H. Cherry
Keyword(s):  
Cytokinin Activity ◽  
Naturally Occurring ◽  
Storage Products ◽  
Quantitative Changes ◽  
Relationship Of ◽  
The Relationship

Application of different concentrations of the naturally occurring cytokinin zeatin 6(4-hydroxy-3-methyl trans-2-butenylamino)purine caused changes in one or more species of tRNAs. With the depletion of storage products from senescing cotyledons quantitative changes in tRNAleu1, 5, 6, tRNAser1–3, and tRNAtyr1–4 were observed. Higher concentrations of zeatin applied as a single spray did not produce significant changes either in the cotyledon or the hypocotyl. The relationship of cytokinin activity to senescing soybean cotyledons is discussed.

scholarly journals Adopting a Practical Statistical Approach for Evaluating Assay Agreement in Drug Discovery

2005 ◽  
Vol 10 (5) ◽  
pp. 508-516 ◽  
Author(s):  
Dongyu Sun ◽  
Adrian Whitty ◽  
James Papadatos ◽  
Miki Newman ◽  
Jason Donnelly ◽  
...  
Keyword(s):  
Drug Discovery ◽  
High Throughput Screening ◽  
Statistical Approach ◽  
Data Sets ◽  
Detection Technology ◽  
Quantitative Changes ◽  
Relationship Of ◽  
The Relationship ◽  
Data Equivalence ◽  
Assay Conditions

The authors assess the equivalence of 2 assays and put forward a general approach for assay agreement analysis that can be applied during drug discovery. Data sets generated by different assays are routinely compared to each other during the process of drug discovery. For a given target, the assays used for high-throughput screening and structure-activity relationship studies willmost likely differ in their assay reagents, assay conditions, and/or detection technology, whichmakes the interpretation of data between assays difficult, particularly as most assays are used to measure quantitative changes in compound potency against the target. To better quantify the relationship of data sets from different assays for the same target, the authors evaluated the agreement between results generated by 2 different assays that measure the activity of compounds against the same protein, ALK5. The authors showthat the agreement between data sets can be quantified using correlation and Bland-Altman plots, and the precision of the assays can be used to define the expectations of agreement between 2 assays. They propose a scheme for addressing issues of assay data equivalence, which can be applied to address questions of how data sets compare during the lead identification and lead optimization processes in which assays are frequently added and changed.

The Relationship of Vehicle to Target Organ Toxicology Induced by the Naturally Occurring Nitrile 1-Cyano-2-hydroxy-3-butene

1989 ◽  
Vol 12 (3) ◽  
pp. 377-385
Author(s):  
MATTHEW A WALLIG ◽  
DANIEL H GOULD ◽  
JAN VAN STEENHOUSE ◽  
MARTIN J FETTMAN ◽  
CALVIN C WILLHITE
Keyword(s):  
Target Organ ◽  
Naturally Occurring ◽  
Relationship Of ◽  
The Relationship

Relationships among 2:1 layer silicates

1969 ◽  
Vol 37 (286) ◽  
pp. 206-209 ◽  
Author(s):  
E. J. W. Whittaker
Keyword(s):  
Charge Balance ◽  
Layer Silicates ◽  
Naturally Occurring ◽  
Relationship Of ◽  
The Relationship ◽  
The Ideal

SummaryThe relationships between the 2:1 layer silicates are discussed in terms of the charge balance between the ions occupying X, Y, and Z sites. This brings out the relationship of glauconite to the illites, and clarifies the reason for the ideal occupancy of the Y sites in montmorillonite. It not only shows hectorite, saponite, and sauconite to be tri-octahedral smectites, but also shows vermiculite to be a tri-octahedral analogue of the illites. Apparently anomalous differences in permitted compositions of the di-octahedral and tri-octahedral micas are explained in terms of mismatch between the tetrahedral and octahedral layers, and it is shown that ephesite is to be regarded as a tri-octahedral common mica, not an analogue of margarite. Anandite is the nearest known naturally occurring equivalent to a tri-octahedral analogue of margarite, but the true analogue is a barium magnesium mica synthesized by Frondel and Ito.

Chromatographic Analysis of Rubber Compounding Ingredients and Their Identification in Vulcanizates

1948 ◽  
Vol 21 (1) ◽  
pp. 195-219 ◽  
Author(s):  
L. J. Bellamy ◽  
J. H. Lawrie ◽  
E. W. S. Press
Keyword(s):  
Degradation Products ◽  
Chemical Methods ◽  
Naturally Occurring ◽  
Single Chemical ◽  
Coloring Matter ◽  
Relationship Of ◽  
Acetone Extracts ◽  
The Relationship ◽  
Subsequent Identification ◽  
Complex Subject

Abstract The work is still in a preliminary stage, but sufficient has now been done to demonstrate the applicability of chromatographic methods to rubber analysis. The acetone extracts of vulcanizates are complex mixtures not readily amenable to analysis by normal chemical methods. By the use of this elegant technique, however, it has been possible to effect the efficient separation of wax, fat acids, accelerators, and antioxidants, not only from each other but also from naturally occurring coloring matter and from degradation products. The subsequent identification of the main fractions is then a relatively simple matter, as tests such as the cobalt oleate reaction for accelerators and the spot reactions for antioxidants can be applied without interference from any other components. The elegance of the method is further demonstrated by the fact that it can be used in the identification of components present in much smaller quantities than are detectable by other chemical methods. The accelerators and antioxidants studied so far are rather limited in number, but cover the main classes of these materials, and the method should, therefore, be applicable to the analysis of a number of technical vulcanizates, and the authors have, in fact, already made use of it with some success for this purpose. It is noteworthy that the adsorption and elution processes are quantitative, and that the whole of the material put on to a column can, therefore, be recovered from the various fractions. This, therefore, offers the possibility of quantitative work on such problems as the rate of consumption of accelerators during cure or the relationship of antioxidant content to behavior on aging. Such work would necessarily be restricted to experiments using pure accelerators and pure antioxidants which are single chemical entities. In this connection the degradation products obtained from mixes accelerated with T.M.T. or M.B.T.S. or D.P.G. are of interest both in the actual isolation of the components in question and in partial confirmation of the work of others in this field. A much more intensive study of the degradation products of each accelerator in mixes cured to varying degrees may well throw more light on the complex subject of accelerators. Although, therefore, the authors have been able to show the utility of chromatography for their own particular analytical problems, it is likely, ultimately, to be of great value in the exploration of some of the fundamental problems of rubber chemistry.

THE C3-ACTIVATOR SYSTEM: AN ALTERNATE PATHWAY OF COMPLEMENT ACTIVATION

1971 ◽  
Vol 134 (3) ◽  
pp. 90-108 ◽  
Author(s):  
Otto Götze ◽  
Hans J. Müller-Eberhard
Keyword(s):  
Molecular Weight ◽  
Complement Activation ◽  
Activation Mechanism ◽  
E Coli ◽  
Clinical Observations ◽  
Naturally Occurring ◽  
Acidic Peptide ◽  
Relationship Of ◽  
The Relationship ◽  
Activator System

Evidence has accumulated indicating the existence of a second complement activation mechanism which is functionally analogous to C1, C2, and C4. The noncomplement protein C3PA, previously recognized through its ability to form a complex enzyme with a protein from cobra venom, appears to be the precursor of the C4,2 analogue. It is a thermolabile ß-globulin with a molecular weight of 80,000. When serum is treated with naturally occurring plant or bacterial polysaccharides, the C3PA is cleaved into at least two fragments, one having the electrophoretic mobility of a γ-globulin and a molecular weight of 60,000, and the other being an acidic peptide with a molecular weight of 20,000. The larger fragment has the ability to cleave C3 into C3a and C3b and is therefore called C3 activator. It arises from the action of an as yet unidentified serum enzyme upon the C3PA, which is tentatively called C3PA convertase. In addition to endotoxins, yeast cell walls, inulin, and agar, aggregates of immunoglobulins were found to be activating substances, including human IgA, guinea pig γ1, and duck antibody. Serum depleted of C3PA had reduced E. coli bactericidal and increased hemolytic activity. The relationship of the C3-activator system to experimental and clinical observations has been discussed.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

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