scholarly journals THE RATE OF OVULATION IN THE DOMESTIC FOWL DURING THE PULLET YEAR

1921 ◽  
Vol 3 (4) ◽  
pp. 431-437 ◽  
Author(s):  
Samuel Brody
Keyword(s):  
Chemical Reaction ◽  
Domestic Fowl ◽  
Autocatalytic Reaction ◽  
Limiting Factor ◽  
Rate Of Growth

The rate of ovulation of the domestic fowl may be expressed by the equation of an autocatalytic chemical reaction. This is not surprising in view of the fact that the rate of growth may also be expressed by such an equation, and that the rate of ovulation is probably an index of the growth of the eggs. This brings the phenomenon of ovulation in the hen under the general subject of growth, and substantiates the generality and the probability of the hypothesis that growth, or at any rate the limiting factor of growth, is an autocatalytic reaction.

Implications of rRNA Operon Copy Number and Ribosome Content in the Marine Oligotrophic Ultramicrobacterium Sphingomonassp. Strain RB2256

1998 ◽  
Vol 64 (11) ◽  
pp. 4433-4438 ◽  
Author(s):  
Fitri Fegatella ◽  
Julianne Lim ◽  
Staffan Kjelleberg ◽  
Ricardo Cavicchioli
Keyword(s):  
Growth Rate ◽  
Copy Number ◽  
Heterotrophic Bacteria ◽  
Single Copy ◽  
Rrna Operon ◽  
Limiting Factor ◽  
E Coli ◽  
Rate Of Growth ◽  
Rates Of Growth ◽  
Low Rate

ABSTRACT Sphingomonas sp. strain RB2256 is a representative of the dominant class of ultramicrobacteria that are present in marine oligotrophic waters. In this study we examined the rRNA copy number and ribosome content of RB2256 to identify factors that may be associated with the relatively low rate of growth exhibited by the organism. It was found that RB2256 contains a single copy of the rRNA operon, in contrast to Vibrio spp., which contain more than eight copies. The maximum number of ribosomes per cell was observed during mid-log phase; however, this maximum content was low compared to those of faster-growing, heterotrophic bacteria (approximately 8% of the maximum ribosome content of Escherichia coli with a growth rate of 1.5 h−1). The low number of ribosomes per cell appears to correlate with the low rate of growth (0.16 to 0.18 h−1) and the presence of a single copy of the rRNA operon. However, on the basis of cell volume, RB2256 appears to have a higher concentration of ribosomes than E. coli (approximately double that of E. coli with a growth rate of 1.5 h−1). Ribosome numbers reached maximum levels during mid-log-phase growth but decreased rapidly to 10% of maximum during late log phase through 7 days of starvation. The cells in late log phase and at the onset of starvation displayed an immediate response to a sudden addition of excess glucose (3 mM). This result demonstrates that a ribosome content 10% of maximum is sufficient to allow cells to immediately respond to nutrient upshift and achieve maximum rates of growth. These data indicate that the bulk of the ribosome pool is not required for protein synthesis and that ribosomes are not the limiting factor contributing to a low rate of growth. Our findings show that the regulation of ribosome content, the number of ribosomes per cell, and growth rate responses in RB2256 are fundamentally different from those characteristics in fast-growing heterotrophs like E. coliand that they may be characteristics typical of oligotrophic ultramicrobacteria.

Computational Study of Traveling Wave Solutions of Isothermal Chemical Systems

2016 ◽  
Vol 19 (5) ◽  
pp. 1461-1472 ◽  
Author(s):  
Yuanwei Qi ◽  
Yi Zhu
Keyword(s):  
Chemical Reaction ◽  
Traveling Waves ◽  
Flow Reactor ◽  
Computational Study ◽  
Chemical Species ◽  
Traveling Wave Solutions ◽  
Reaction Diffusion ◽  
Autocatalytic Reaction ◽  
Reaction Diffusion Systems ◽  
Diffusion Systems

AbstractThis article studies propagating traveling waves in a class of reaction-diffusion systems which model isothermal autocatalytic chemical reactions as well as microbial growth and competition in a flow reactor. In the context of isothermal autocatalytic systems, two different cases will be studied. The first is autocatalytic chemical reaction of order m without decay. The second is chemical reaction of order m with a decay of order n, where m and n are positive integers and m>n≥1. A typical system in autocatalysis is A+2B→3B and B→C involving two chemical species, a reactant A and an auto-catalyst B and C an inert chemical species.The numerical computation gives more accurate estimates on minimum speed of traveling waves for autocatalytic reaction without decay, providing useful insight in the study of stability of traveling waves.For autocatalytic reaction of order m = 2 with linear decay n = 1, which has a particular important role in chemical waves, it is shown numerically that there exist multiple traveling waves with 1, 2 and 3 peaks with certain choices of parameters.

scholarly journals THE RATE OF GROWTH OF THE DOMESTIC FOWL

1921 ◽  
Vol 3 (6) ◽  
pp. 765-770 ◽  
Author(s):  
Samuel Brody
Keyword(s):  
Guinea Pig ◽  
Domestic Fowl ◽  
Growth Period ◽  
Rate Of Growth ◽  
Monomolecular Reaction

This paper points out the fact that the growth period of the domestic fowl is analogous to that of the mammal, being composed of three, or perhaps four, cycles; two of these cycles are postembryonic with maxima at about 8 and 18 weeks varying somewhat with the breed and two or at least one, are embryonic with maxima at 11 to 12 and 15 to 16 days of age. Hatching occurs during the first part of the second or third cycle resembling in this respect the guinea pig rather than the mouse. The velocity curves of each of these cycles are similar to and can be represented by the equation of an autocatalytic monomolecular reaction.

scholarly journals THE RATE OF GROWTH OF THE DAIRY COW

1923 ◽  
Vol 5 (4) ◽  
pp. 445-449 ◽  
Author(s):  
Samuel Brody ◽  
Arthur C. Ragsdale ◽  
Charles W. Turner
Keyword(s):  
Chemical Reaction ◽  
Dairy Cow ◽  
Rate Of Growth ◽  
Entire Duration

An extensive amount of data is presented on the growth in weight of the dairy cow from 2 to 17 years of age, covering practically the entire duration of life. The data show that after the age of 2 years the rate of growth declines in a non-cyclic manner. The course of decline in growth follows the course of decline of a monomolecular chemical reaction; that is, the percentage decline in growth with age is constant.

Nutritive value of the protein of white and wholemeal bread in relation to the growth of rats

1956 ◽  
Vol 145 (919) ◽  
pp. 270-279 ◽  
Keyword(s):  
Amino Acid ◽  
Essential Amino Acid ◽  
Nutritive Value ◽  
Limiting Factor ◽  
Lysine Content ◽  
White Bread ◽  
Rate Of Growth ◽  
Weanling Rats ◽  
The Difference ◽  
Wholemeal Bread

The comparative value of the protein of wholemeal bread and white bread, in promoting the growth of young rats of both sexes, has been re-examined. With weanling rats the results confirmed previous observations, made by other workers, that the protein of wholemeal bread promotes a better rate of growth than that of white bread. This difference in the rate of growth was also observed when the diets contained 4% skim milk powder and 10% potato powder. With older rats (starting about 5 to 6 weeks afterweanling) the difference in rate of growth, on the diets containing wholemeal bread com pared with those containing white bread, was not so pronounced with male rats and was insignificant with females. Following these observations the lysine content of the wholemeal and white-bread diets was determined using the analytical technique of Moore & Stein (1951) with an ion-exchange resin. With these data as a basis the lysine content of the white-bread diets was raised to that of the wholemeal diets by the addition of L-lysine. The rate of growth of male weanling rats on the supplemented white-bread diet was then no longer inferior to that observed with the wholemeal diet. In further experiments the lysine content of both the white-bread and wholemeal diets was raised to about 1%, so that lysine was no longer the limiting factor in either. Male weanling rats grew equally well on both these supplemented diets. Once the lysine requirement was satisfied there was no evidence of any other essential amino-acid being a limiting factor in the white-bread diets, compared with the wholemeal. It is concluded, first, that the difference in the nutritive value of the protein of wholemeal bread and that of white bread (as measured by the rate of growth of the weanling rat) is due to the higher lysine content of the wholemeal bread. Secondly, that the weanling rat is extremely sensitive to small changes in the lysine concentration in diets when the content of this essential amino-acid is in the range 0·3 to 0·5%.

scholarly journals THE RATE OF GROWTH OF THE DAIRY COW

1923 ◽  
Vol 6 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Samuel Brody ◽  
Arthur C. Ragsdale ◽  
Charles W. Turner
Keyword(s):  
Body Weight ◽  
Chemical Reaction ◽  
Dairy Cow ◽  
Good Measure ◽  
Milk Secretion ◽  
Velocity Constant ◽  
Rate Of Growth ◽  
Maximum Body

It is shown that from 2 years, the age when milk secretion usually begins, to 9 years, the age of maximum body weight, the increase of milk secretion with age follows the course of growth in body weight— both can be accurately represented by the equation of a monomolecular chemical reaction having a velocity constant of approximately the same numerical value. While increase in milk secretion and increase in body weight with age follow the same course, it is shown that increasing body weight contributes only about 20 per cent to increasing milk secretion with age. The fact that milk secretion and body weight follow the same course, even though they are largely independent of each other indicates that increase in body weight is a good measure of growth of the dairy cow; this fact also shows that the increase of milk secretion with age may be used as a measure of growth. The fact that milk secretion, like body weight, follows the course of a chemical reaction, adds further support to the theory that growth is limited by a chemical reaction.

scholarly journals Inheritance of Rate of Growth in Domestic Fowl

1934 ◽  
Vol 13 (6) ◽  
pp. 348-352 ◽  
Author(s):  
V.S. Asmundson ◽  
I. Michael Lerner
Keyword(s):  
Domestic Fowl ◽  
Rate Of Growth

scholarly journals THE RATE OF SENESCENCE OF THE DOMESTIC FOWL AS MEASURED BY THE DECLINE IN EGG PRODUCTION WITH AGE

1923 ◽  
Vol 6 (1) ◽  
pp. 41-45 ◽  
Author(s):  
Samuel Brody ◽  
Earl W. Henderson ◽  
H. L. Kempster
Keyword(s):  
Chemical Reaction ◽  
Domestic Fowl ◽  
Egg Production ◽  
Physicochemical Process ◽  
Exponential Law ◽  
The Law ◽  
Constant Percentage

Data are presented showing that the course of decline of egg production with age in the domestic fowl from the time laying begins up to and including 8 years follows an exponential law, that is, each year's egg production is a constant percentage of the preceding year's production (88 per cent in the group of fowl studied). Since the exponential law is the same as the law of monomolecular change in chemistry, and since the course of egg production with age may be taken as an index of the course of senescence of organs, or tissues limiting egg production, it is suggested that this exponential law of egg production substantiates the idea that senescence is a physicochemical process the course of which is limited by a chemical reaction. It is shown that the exhaustion of the oocytes is not likely to be the factor limiting the course of egg production.

scholarly journals Inheritance of Rate of Growth in Domestic Fowl

1933 ◽  
Vol 12 (4) ◽  
pp. 250-255 ◽  
Author(s):  
V.S. Asmundson ◽  
I. Michael Lerner
Keyword(s):  
Domestic Fowl ◽  
Rate Of Growth
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