The surface activity of the phytotoxin cerato-ulmin

1982 ◽  
Vol 60 (8) ◽  
pp. 1414-1422 ◽  
Author(s):  
Paul S. Russo ◽  
Frank D. Blum ◽  
John D. Ipsen ◽  
Yusuf J. Abul-Hajj ◽  
Wilmer G. Miller
Keyword(s):  
Surface Activity ◽  
Aqueous Ethanol ◽  
Vascular System ◽  
Wilt Disease ◽  
Air Bubbles ◽  
Low Concentrations ◽  
Air Water Interface ◽  
Response To Stress ◽  
Relationship Of ◽  
The Relationship

The glycoprotein cerato-ulmin, which shows surface activity at concentrations as low as 30 ng/mL, has been found to stabilize air bubbles, both spheroidal and of unusual morphology, in aqueous and aqueous ethanol solutions. In response to stress on a cerato-ulmin thin film, perhaps a monolayer, at an air–water interface, cylindrical and fibrilliform air bubbles are generated. They may be manipulated by application of tension, pressure, or temperature. The relationship of these observations to elm trees infected with the cerato-ulmin producing fungus Ceratocystis ulmi suggests a mechanism whereby exceedingly low concentrations of cerato-ulmin may be concentrated and delivered to intercellular openings, thereby blocking the vascular system of elm trees. The correctness of this mechanism as a major factor in any tree wilt disease remains to be tested.

VITAMIN B12 AND FOLIC ACID VALUES IN PREMATURE INFANTS

PEDIATRICS ◽  
1972 ◽  
Vol 50 (4) ◽  
pp. 584-589
Author(s):  
Ambadas Pathak ◽  
Herman A. Godwin ◽  
Luis M. Prudent
Keyword(s):  
Folic Acid ◽  
Vitamin B12 ◽  
Premature Infants ◽  
Serum Vitamin ◽  
Serum Folate ◽  
Born Infant ◽  
Low Concentrations ◽  
Folate And Vitamin B12 ◽  
Relationship Of ◽  
The Relationship

The relationship of serum vitamin B12 and folic acid was studied in 24 premature infants. In 14 of the 24, low serum vitamin B12 values were found around 40 days of age. Serum folic acid concentrations were less frequently depressed and were usually associated with normal red cell folate values. No correlation between hematocrits and vitamin B12 or folate levels was found. It is suggested that low concentrations of serum folate and vitamin B12 result from low dietary intake coupled with increased demand by the prematurely born infant.

EVALUATION OF THE VESSEL AGE BY APPLYING THE ACCELERATION PLETHYSMOGRAM ANALYSIS

2021 ◽  
pp. 61-67
Author(s):  
Елизавета Александровна Молчанова ◽  
Петр Вячеславович Лужнов
Keyword(s):  
Blood Vessels ◽  
Pulse Wave ◽  
Vascular System ◽  
Vascular Wall ◽  
Second Derivative ◽  
Contour Analysis ◽  
Physiological Factors ◽  
Vascular Age ◽  
Relationship Of ◽  
The Relationship

В работе приведены понятия жесткости, эластичности и тонуса сосудов, а также же их взаимосвязь с общим состоянием сосудистой стенки. Описан индекс, объединяющий влияние вышеперечисленных факторов на состояние сосудистой системы и дающий представление о возрасте сосудов пациента, а также показана связь этого индекса с возрастом человека. Представлен обзор способов определения возраста сосудов с помощью контурного анализа пульсовой волны. Среди предложенных способов был выделен подход на основе контурного анализа сигнала пульсовой волны, а также ее второй производной. В данном исследовании проводилась разработка алгоритма расчета показателя возраста сосудов (VA), базирующаяся на анализе сигнала и его второй производной. При этом особое внимание уделялось физической интерпретации параметров, входящих в состав расчетной формулы. С помощью представленного алгоритма в группе из трех испытуемых был определен сосудистый возраст. Из анализа полученных результатов было выявлено влияние физиологических факторов на значение возраста сосудов. Предложены методики, позволяющие исключить влияние этих факторов на значения показателя VA и тем самым получить более точные результаты. Также представлены стратегии дальнейшего развития исследований в этом направлении In The paper presents the concepts of rigidity, elasticity and tone of blood vessels, as well as their relationship with the general state of the vascular wall. An index is described that combines the influence of the above factors on the state of the vascular system and gives an idea of the age of the patient's vessels, and also shows the relationship of this index with the age of a person. An overview of the methods for determining the age of blood vessels using the contour analysis of the pulse wave is presented. Among the proposed methods, an approach based on the contour analysis of the pulse wave signal, as well as its second derivative, was singled out. In this study, an algorithm was developed for calculating the indicator of vascular age (VA), based on the analysis of the signal and its second derivative. In this case, special attention was paid to the physical interpretation of the parameters included in the calculation formula. Using the presented algorithm, vascular age was determined in a group of three subjects. From the analysis of the results obtained, the influence of physiological factors on the value of the age of the vessels was revealed. Methods are proposed that allow to exclude the influence of these factors on the values of the VA indicator and thereby obtain more accurate results. Also presented are strategies for the further development of research in this direction

The relationship of social vocalizations to surface behavior and aggression in the Hawaiian humpback whale (Megaptera novaeangliae)

1986 ◽  
Vol 64 (10) ◽  
pp. 2075-2080 ◽  
Author(s):  
Gregory K. Silber
Keyword(s):  
Surface Activity ◽  
Group Size ◽  
Social Dominance ◽  
Humpback Whale ◽  
Megaptera Novaeangliae ◽  
Adult Males ◽  
Surface Behavior ◽  
Relationship Of ◽  
Large Groups ◽  
The Relationship

Humpback whale (Megaptera novaeangliae) social vocalizations (nonsong sounds) were clearly related to whale group size and surface activity. Social sounds occurred almost exclusively in groups containing three or more whales and were rarely heard near single whales, pairs, or cow–calf groups. Large groups (3 to 20 individuals) vocalized at an overall mean rate of 43.1 ± 55.52 sounds per whale/h. Group size changed frequently and a dramatic increase in vocalization rate resulted when a new whale entered a group. Large groups engaged in flurries of surface activity, such as breaching, flipper- and tail-slapping, and underwater bubbling. Aggressive encounters resulted from male–male interaction. Social sounds probably acted to demonstrate aggression or agitation as adult males competed for temporary social dominance within the group and for proximity to the female. Likewise, visual displays may have been used as threats in close quarters and were apparently produced in conjunction with sounds to convey levels of aggression. Although other studies suggested that surface activity increased with group size, I found a negative correlation between activity and group size, both in the group as a whole and per individual. In contrast, social vocalizations per group increased with group size while the vocalization rate per individual did not vary significantly with increasing group size.

The Relationship of Properties of Synthetic Poly(Isoprene) and Natural Rubber in The Factory. The Effect of Non-Rubber Constituents of Natural Rubber

1973 ◽  
Vol 46 (1) ◽  
pp. 47-66 ◽  
Author(s):  
E. C. Gregg ◽  
J. H. Macey
Keyword(s):  
Natural Rubber ◽  
Protein Molecule ◽  
Insoluble Fraction ◽  
Prosthetic Group ◽  
Rubber Material ◽  
Green Strength ◽  
Denatured Protein ◽  
Low Concentrations ◽  
Relationship Of ◽  
The Relationship

Abstract The causes of some of the differences in properties between compounded natural rubber and compounded synthetic poly (isoprene) have been traced to the insoluble non-rubber material in natural rubber. This material is mostly denatured proteins and is responsible for the higher modulus, faster scorch time, higher heat buildup, and higher hot tear strength of natural rubber. These properties may be related to the pigment effect of the denatured protein to act as a reinforcing filler at low concentrations (3–4 per cent by wt) as well as a curing activator. The greater green strength of compounded natural rubber has been related to its more perfect configurational regularity which contributes to faster crystallization. The crystallite concentration increases with increasing stress and the crystallites act like a reversible reinforcing pigment which disappears when the stress is released. The faster plastication rate has been related to the synthetic stabilizers used. Natural rubber hydrocarbon has been shown to be a high molecular lactone arranged in a six membered ring. We speculate natural rubber forms as a prosthetic group connected through a lactone linkage (or the δ-hydroxy acid precursor to the lactone) to a protein molecule in the cell of hevea brasiliensis. It is this structure of a high molecular weight hydrocarbon (natural rubber) attached to a (denatured) protein molecule that accounts for the remarkable dispersability of the insoluble fraction of natural rubber in rubber solvents : the rubber end of the structure tends to dissolve in the rubber solvent while the highly polar, insoluble protein end prevents solution. This structure is the reverse of a micelle in water in principle.

Studies in the Alismataceae. III. Floral anatomy of Ranalisma humile

1973 ◽  
Vol 51 (5) ◽  
pp. 891-897 ◽  
Author(s):  
W. A. Charlton ◽  
A. Ahmed
Keyword(s):  
Vascular System ◽  
Floral Anatomy ◽  
Vascular Anatomy ◽  
Vascular Supply ◽  
Variable Amount ◽  
Peripheral Vascular ◽  
Two Systems ◽  
A Minor ◽  
Relationship Of ◽  
The Relationship

The flower of Ranalisma humile is comparable in morphology to those of other alismads. The vascular anatomy is noteworthy. Flowers of R. humile are provided with a major (central) vascular system supplying androecial and gynoecial vasculature and a variable amount of the sepal and petal vasculature, and a minor (peripheral) system which supplies the rest of the perianth vasculature. There is very little anastomosis between the two systems. It is suggested that the variability of perianth vascular supply reflects variability in timing of differentiation events. The occurrence of an almost independent peripheral vascular system is probably of significance in a consideration of the relationship of Ranalisma humile to other alismads.

scholarly journals Commitment to expression of the metalloendopeptidases, collagenase and stromelysin: relationship of inducing events to changes in cytoskeletal architecture.

1986 ◽  
Vol 102 (3) ◽  
pp. 697-702 ◽  
Author(s):  
Z Werb ◽  
R M Hembry ◽  
G Murphy ◽  
J Aggeler
Keyword(s):  
Cytochalasin B ◽  
Synovial Fibroblasts ◽  
Heterogeneous Population ◽  
Minimum Period ◽  
Low Concentrations ◽  
Relationship Of ◽  
The Relationship ◽  
Rate Limiting ◽  
Dose Dependent Increase ◽  
Dose Dependent

Agents that alter the morphology of rabbit synovial fibroblasts induce synthesis of the metalloendopeptidases, collagenase and stromelysin. We studied the relationship of cytoskeletal changes to the commitment to expression of these metalloendopeptidases. Cells treated with cytochalasin B (CB) or 12-O-tetradecanoylphorbol-13-acetate rounded, and only cells that had lost their stress fibers expressed collagenase and stromelysin, as determined by immunofluorescence. We concentrated on the effects of CB because of its rapid reversibility. When CB was added for 1-24 h, then removed, the cells respread within 30-60 min. The minimum period of CB treatment that committed cells to the subsequent synthesis of collagenase and stromelysin was 3 h. After initial treatment with 2 micrograms/ml CB for 3-24 h, or with various concentrations of CB (0-2 micrograms/ml) for 24 h, both enzyme activity and biosynthesis of the proenzymes showed a graded increase when measured at 24 h. Even after treatment with 2 micrograms/ml CB for only 3 h, greater than 85% of all cells were positive for both collagenase and stromelysin when cells were monitored by immunofluorescence. In contrast, when the dependence of collagenase and stromelysin expression on the inducing concentration of CB was examined, there was a dose-dependent increase in the number of cells positive for collagenase and stromelysin, as determined by immunofluorescence. Thus, at low concentrations of CB (less than 0.5 micrograms/ml), a heterogeneous population response was observed. These results suggest that the commitment of fibroblasts to induction of the metalloproteinases is a stochastic process in which a second signal that correlates with the disruption of the actin cytoskeleton may be rate-limiting for collagenase and stromelysin gene expression.

Surface Activity−Compressibility Relationship of Proteins at the Air−Water Interface

Langmuir ◽  
1999 ◽  
Vol 15 (4) ◽  
pp. 1392-1399 ◽  
Author(s):  
Lev Razumovsky ◽  
Srinivasan Damodaran
Keyword(s):  
Surface Activity ◽  
Water Interface ◽  
Air Water Interface ◽  
Relationship Of

The relationship of fatty acid composition and surface activity of lung extracts

1978 ◽  
Vol 32 (2) ◽  
pp. 195-206 ◽  
Author(s):  
J.M. Burneil ◽  
E.C. Kyriakides ◽  
R.H. Edmonds ◽  
J.A. Balint
Keyword(s):  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Surface Activity ◽  
Acid Composition ◽  
Relationship Of ◽  
The Relationship
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