scholarly journals Kinetics of continuous growth cultures using the logistic growth curve

1976 ◽  
Vol 18 (7) ◽  
pp. 1029-1032 ◽  
Author(s):  
Enrique J. La Motta
Keyword(s):  
Growth Curve ◽  
Logistic Growth ◽  
Continuous Growth ◽  
Kinetics Of

Responses of Subterranean Clover Communities to Temperature. I. Dry Matter Production and Plant Morphogenesis

1976 ◽  
Vol 3 (4) ◽  
pp. 527 ◽  
Author(s):  
S Fukai ◽  
JH Silsbury
Keyword(s):  
Leaf Area ◽  
Growth Curve ◽  
Dry Matter ◽  
Subterranean Clover ◽  
Experimental Period ◽  
Main Stem ◽  
Logistic Growth ◽  
Similar Time ◽  
Plant Parts ◽  
Leaf Appearance

Subterranean clover communities were grown in temperature-controlled naturally lit glasshouses at 15, 20, 25 and 30�C. Dry matter yield, leaf area and the distribution of dry matter between plant parts were determined at about 14-day intervals for up to 130 days from planting. Leaf appearance, leaf death, leaf number and growth of laterals were observed for individual plants in the community over a similar time period. A logistic growth curve was found for each temperature and crop growth rate calculated from the equation fitted for each growth curve. The optimum temperature for growth was relatively high (20-25°C) when plants were young, but decreased during growth so that after 100 days total dry matter was inversely related to temperature over the range 15-30°C. Both the rate of leaf appearance and the rate of leaf death on the main stem were constant at each temperature during the experimental period and were directly related to temperature. The number of leaves per unit ground area was determined mainly by the rates of leaf appearance and leaf death on the main stem, since the contribution of laterals was small. The proportion of stem and petiole to total dry matter increased, and that of green leaf lamina decreased, with increase in total dry matter. Neither was markedly affected by temperature. An inverse relationship between specific leaf area and temperature resulted in a lower ratio of leaf area to total dry matter at 15°C compared with that at 20, 25 or 30°C.

Determinants of diversity in higher taxonomic categories

Paleobiology ◽  
1980 ◽  
Vol 6 (4) ◽  
pp. 444-450 ◽  
Author(s):  
James W. Valentine
Keyword(s):  
Species Richness ◽  
New Species ◽  
Growth Curve ◽  
High Frequency ◽  
Maximum Level ◽  
Logistic Growth ◽  
Higher Taxa ◽  
Equilibrium Level ◽  
Higher Categories ◽  
Taxonomic Categories

It is often assumed that, if a few species are introduced into a relatively empty environment, the subsequent diversification will take the form of a logistic growth curve, rising to an equilibrium level of species richness. The diversifications of taxa in higher categories commonly resemble logistic curves, although there are no well-defined theoretical bases for such a resemblance.A model of diversification of taxa in higher categories is based on the notion that many taxa originate rapidly. Relatively small changes leading to new species occur at a high frequency, while larger changes leading to progressively higher taxa occur with progressive rarity. During diversification in an empty environment, few large changes will occur before the environment is filled. The rate of filling, relative to the rate of production of higher taxa, determines the richness of taxa in higher categories and gives the diversification curves a logistic appearance although the maximum level achieved is not an equilibrium. Subsequently, opportunities for diversification will generally lead only to the appearance of taxa in progressively lower categories.

Evaluation of production and kinetics parameters of rare sugar (D-tagatose) using biocatalyst Arthrobacter globiformis

2016 ◽  
Vol 27 (1) ◽  
pp. 71-78 ◽  
Author(s):  
Jayamuthunagai Jayaraman ◽  
Pennathur Gautam
Keyword(s):  
Wild Strain ◽  
Gluconobacter Oxydans ◽  
Acetic Acid Bacteria ◽  
Inoculum Size ◽  
Logistic Growth ◽  
Biomass Estimation ◽  
Arthrobacter Globiformis ◽  
Kinetics Parameters ◽  
Content Type ◽  
Kinetics Of

Purpose – Dulcitol (Galactitol) is a sugar alcohol which is produced by redox reaction of galactose. It has been reported that the D-tagatose can be produced from dulcitol (D-galactitol) via the oxidation reaction by the acetic acid bacteria such as Arthobacter globiformis, Gluconobacter oxydans. The D-tagatose sugar is a ketohexose monosaccharide sweetener, which is an isomer of D-galactose. D-tagatose is rarely found in nature and it can be utilized in many ways particular in prebiotic property. The purpose of this paper is to speak about the production and kinetics of D-tagatose from dulcitol using a wild strain of Arthobacter globiformis MTCC 944. Design/methodology/approach – The wild strain Arthobacter globiformis was procured from Microbial Type Culture Collection, Chandigarh and was grown in slants (Dulcitol of 2 percent (w/v)) by sub culturing for every two weeks until transferred to production medium containing 10 percent (w/v) of dulcitol operating aerobically at 25°C and 180 rpm. Biomass estimation was carried out taking samples periodically and measuring its OD value using spectronic-20D spectrophotometer at 600 nm. Kinetics of biomass was determined using Logistic growth kinetic model and that of D-tagatose production was estimated using Leudking-Piret model. Findings – The maximum production of D-tagatose (3.82 g/L) was obtained at the initial dulcitol concentration of 20 g/L and at a pH of 6.0 and temperature of 25°C. Effect of inoculum size on the fermentation of D-tagatose was studied. Threefold increases in yield of tagatose was achieved at the higher inoculum concentration of 24 percent v/v. Originality/value – The strain Arthrobacter globiformis, selected for the production of D-tagatose is not much investigated strain. Dulcitol, the substrate chosen for the study is less expensive when compare with galactose which is largely used by the investigators.

Bacterial growth in space flight: logistic growth curve parameters for Escherichia coli and Bacillus subtilis

1999 ◽  
Vol 51 (2) ◽  
pp. 229-234 ◽  
Author(s):  
M. A. Kacena ◽  
G. A. Merrell ◽  
B. Manfredi ◽  
E. E. Smith ◽  
D. M. Klaus ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Bacterial Growth ◽  
Growth Curve ◽  
Space Flight ◽  
Logistic Growth

scholarly journals Association mining based approach to analyze COVID-19 response and case growth in the United States

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Satya Katragadda ◽  
Raju Gottumukkala ◽  
Ravi Teja Bhupatiraju ◽  
Azmyin Md. Kamal ◽  
Vijay Raghavan ◽  
...  
Keyword(s):  
United States ◽  
Data Mining ◽  
Growth Curve ◽  
Face Mask ◽  
The United States ◽  
Quality Data ◽  
Logistic Growth ◽  
Association Mining ◽  
Rule Mining ◽  
The Common

AbstractContaining the COVID-19 pandemic while balancing the economy has proven to be quite a challenge for the world. We still have limited understanding of which combination of policies have been most effective in flattening the curve; given the challenges of the dynamic and evolving nature of the pandemic, lack of quality data etc. This paper introduces a novel data mining-based approach to understand the effects of different non-pharmaceutical interventions in containing the COVID-19 infection rate. We used the association rule mining approach to perform descriptive data mining on publicly available data for 50 states in the United States to understand the similarity and differences among various policies and underlying conditions that led to transitions between different infection growth curve phases. We used a multi-peak logistic growth model to label the different phases of infection growth curve. The common trends in the data were analyzed with respect to lockdowns, face mask mandates, mobility, and infection growth. We observed that face mask mandates combined with mobility reduction through moderate stay-at-home orders were most effective in reducing the number of COVID-19 cases across various states.

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