scholarly journals Growth Rates, Growth Models and Future Projections of Sorghum in Telangana State

2020 ◽  
Vol 9 (12) ◽  
pp. 2514-2524
Author(s):  
R. Srinivas ◽  
D. Srinivasa Chary
Keyword(s):  
Growth Rates ◽  
Growth Models ◽  
Future Projections ◽  
Telangana State

Dynamic Predictive Model for Growth of Bacillus cereus from Spores in Cooked Beans

2017 ◽  
Vol 81 (2) ◽  
pp. 308-315 ◽  
Author(s):  
Vijay K. Juneja ◽  
Abhinav Mishra ◽  
Abani K. Pradhan
Keyword(s):  
Bacillus Cereus ◽  
Growth Rates ◽  
Linear Models ◽  
Growth Models ◽  
Maximum Growth ◽  
Effect Of Temperature ◽  
Coefficient Of Determination ◽  
Growth Data ◽  
Three Phase ◽  
Primary Model

ABSTRACT Kinetic growth data for Bacillus cereus grown from spores were collected in cooked beans under several isothermal conditions (10 to 49°C). Samples were inoculated with approximately 2 log CFU/g heat-shocked (80°C for 10 min) spores and stored at isothermal temperatures. B. cereus populations were determined at appropriate intervals by plating on mannitol–egg yolk–polymyxin agar and incubating at 30°C for 24 h. Data were fitted into Baranyi, Huang, modified Gompertz, and three-phase linear primary growth models. All four models were fitted to the experimental growth data collected at 13 to 46°C. Performances of these models were evaluated based on accuracy and bias factors, the coefficient of determination (R2), and the root mean square error. Based on these criteria, the Baranyi model best described the growth data, followed by the Huang, modified Gompertz, and three-phase linear models. The maximum growth rates of each primary model were fitted as a function of temperature using the modified Ratkowsky model. The high R2 values (0.95 to 0.98) indicate that the modified Ratkowsky model can be used to describe the effect of temperature on the growth rates for all four primary models. The acceptable prediction zone (APZ) approach also was used for validation of the model with observed data collected during single and two-step dynamic cooling temperature protocols. When the predictions using the Baranyi model were compared with the observed data using the APZ analysis, all 24 observations for the exponential single rate cooling were within the APZ, which was set between −0.5 and 1 log CFU/g; 26 of 28 predictions for the two-step cooling profiles also were within the APZ limits. The developed dynamic model can be used to predict potential B. cereus growth from spores in beans under various temperature conditions or during extended chilling of cooked beans.

scholarly journals Mask mandate and use efficacy for COVID-19 containment in US States

2021 ◽  
pp. 55
Author(s):  
◽  
Keyword(s):  
United States ◽  
Growth Rates ◽  
Growth Models ◽  
Maximum Growth ◽  
The United States ◽  
Us States ◽  
Control And Prevention ◽  
Total Growth ◽  
Lower Maximum ◽  
Lower Infection

Background: COVID-19 pandemic mitigation requires evidence-based strategies. Because COVID-19 can spread via respired droplets, most US states mandated mask use in public settings. Randomized control trials have not clearly demonstrated mask efficacy against respiratory viruses, and observational studies conflict on whether mask use predicts lower infection rates. We hypothesized that statewide mask mandates and mask use were associated with lower COVID-19 case growth rates in the United States. Methods: We calculated total COVID-19 case growth and mask use for the continental United States with data from the Centers for Disease Control and Prevention and Institute for Health Metrics and Evaluation. We estimated post-mask mandate case growth in non-mandate states using median issuance dates of neighboring states with mandates. Results: Earlier mask mandates were not associated with lower total cases or lower maximum growth rates. Earlier mandates were weakly associated with lower minimum COVID-19 growth rates. Mask use predicted lower minimum but not lower maximum growth rates. Growth rates and total growth were comparable between US states in the first and last mask use quintiles during the Fall-Winter wave. These observations persisted for both natural logarithmic and fold growth models and when adjusting for differences in US state population density. Conclusions: We did not observe association between mask mandates or use and reduced COVID-19 spread in US states. COVID-19 mitigation requires further research and use of existing efficacious strategies, most notably vaccination.

Statistical Initiation and Crack Growth Models for Stress Corrosion Cracking

2007 ◽  
Author(s):  
W. J. Shack ◽  
O. K. Chopra
Keyword(s):  
Stress Corrosion ◽  
Crack Growth ◽  
Growth Rates ◽  
Field Data ◽  
Growth Models ◽  
Statistical Distributions ◽  
Parametric Dependencies ◽  
Component Failure Rates ◽  
The Times ◽  
Crack Growth Rates

Statistical distributions of initiation times and crack growth rates are needed for probabilistic fracture mechanics models. Times to failure in laboratory tests on small specimens are about a factor of 1000 shorter than the times to failure of comparably sized “specimens” in the field would have to be in order to get realistic component failure rates. Thus while specimen tests are useful in identifying parametric dependencies, it is unlikely that they can be used directly to develop initiation models for field components without using field data. A scaling approach is proposed to provide a method for pooling data from different size components and for extrapolating experience from one set of components to another set. Estimates of statistical distributions for initiation of stress corrosion cracks are developed from field data for BWR pipe cracking and CRDM cracking. Estimates of statistical distributions of crack growth rates are developed by combining phenomenological models for crack growth rates with expert judgment on the range of input parameters to those models.

Differences in growth rates between habitats of South-east Australian snapper (Chrysophrys auratus)

1989 ◽  
Vol 40 (6) ◽  
pp. 703 ◽  
Author(s):  
RICC Francis ◽  
RH Winstanley
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Growth Models ◽  
Annual Growth ◽  
Positive Bias ◽  
Movement Data ◽  
Length Measurements ◽  
Length Increment

Data on recaptured fish from two tagging experiments on south-east Australian snapper, Chrysophrys auratus, were analysed: 198 fish released in several Victorian locations between 1956 and 1962, and 118 fish released in Port Phillip Bay in 1971 and 1972. Movement data from both experiments were used to classify the fish into habitats (oceanic and bay) and stocks (western and eastern). Length increment data from the earlier experiment indicate that the major growth-rate differences in south-east Australian snapper lie within the western stock (between oceanic and bay habitats) rather than between stocks as suggested by an earlier analysis of the same data. The annual growth rates of 20-30-cm snapper in Port Phillip Bay and Western Port are 17-20% higher than for fish in the ocean. Oceanic growth rates in the western stock appear to be lower than those in the eastern stock. Procedural differences in length measurements at tagging and recapture can introduce a net bias in the length increment that, if ignored (as is conventional in tagging growth models), will bias growth rate estimates. In the earlier tagging experiment, this is shown to have caused a 10% positive bias in growth rate estimates.

Comparison of size-at-age of larval Atlantic cod (Gadus morhua) from different populations based on size- and temperature-dependent growth models

2005 ◽  
Vol 62 (5) ◽  
pp. 1037-1052 ◽  
Author(s):  
A Folkvord
Keyword(s):  
Growth Rates ◽  
Laboratory Experiments ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Growth Models ◽  
Larval Growth ◽  
Growth Potential ◽  
Temperature History ◽  
Temperature Dependent ◽  
Dependent Growth

This study presents the first intraspecific evaluation of larval growth performance across several different experimental scales, environments, and regions of a marine fish species. Size- and temperature-dependent growth models for larval and early juvenile Atlantic cod (Gadus morhua) are developed based on selected laboratory experiments with cod fed in excess. Observed sizes-at-age of cod from several experiments and stocks are compared with predictions from the models using initial size and ambient temperature history as inputs. Comparisons with results from other laboratory experiments reveal that the model predictions represent relatively high growth rates. Results from enclosure experiments under controlled seminatural conditions generally provide growth rates similar to those predicted from the models. The models therefore produce suitable reference growth predictions against which field-based growth estimates can be compared. These comparisons suggest that surviving cod larvae in the sea typically grow at rates close to their size- and temperature-dependent capacity. This suggests that climatic influences will strongly affect the year-to-year variations in growth of cod during their early life history owing to their markedly temperature-dependent growth potential.

scholarly journals Estimation of Staphylococcus aureus Growth Parameters from Turbidity Data: Characterization of Strain Variation and Comparison of Methods

2006 ◽  
Vol 72 (7) ◽  
pp. 4862-4870 ◽  
Author(s):  
R. Lindqvist
Keyword(s):  
Staphylococcus Aureus ◽  
Growth Rates ◽  
Growth Parameters ◽  
Growth Models ◽  
Viable Count ◽  
Detection Methods ◽  
Accurate Estimation ◽  
Data Set ◽  
Time To Detection ◽  
Strain Variability

ABSTRACT Turbidity methods offer possibilities for generating data required for addressing microorganism variability in risk modeling given that the results of these methods correspond to those of viable count methods. The objectives of this study were to identify the best approach for determining growth parameters based on turbidity data and use of a Bioscreen instrument and to characterize variability in growth parameters of 34 Staphylococcus aureus strains of different biotypes isolated from broiler carcasses. Growth parameters were estimated by fitting primary growth models to turbidity growth curves or to detection times of serially diluted cultures either directly or by using an analysis of variance (ANOVA) approach. The maximum specific growth rates in chicken broth at 17°C estimated by time to detection methods were in good agreement with viable count estimates, whereas growth models (exponential and Richards) underestimated growth rates. Time to detection methods were selected for strain characterization. The variation of growth parameters among strains was best described by either the logistic or lognormal distribution, but definitive conclusions require a larger data set. The distribution of the physiological state parameter ranged from 0.01 to 0.92 and was not significantly different from a normal distribution. Strain variability was important, and the coefficient of variation of growth parameters was up to six times larger among strains than within strains. It is suggested to apply a time to detection (ANOVA) approach using turbidity measurements for convenient and accurate estimation of growth parameters. The results emphasize the need to consider implications of strain variability for predictive modeling and risk assessment.

Slow and unsteady: growth of the Australian eastern long-necked turtle near the southern end of its natural range

2018 ◽  
Vol 66 (1) ◽  
pp. 77 ◽  
Author(s):  
Bruce C. Chessman
Keyword(s):  
Growth Rates ◽  
Growth Models ◽  
Logistic Models ◽  
Individual Growth ◽  
Freshwater Turtles ◽  
Turtle Species ◽  
Adult Growth ◽  
Eastern Australia ◽  
Natural Range ◽  
Chelodina Longicollis

Knowledge of growth rates and maturation times of freshwater turtles is important in assessing population viability. I analysed growth of Australian eastern long-necked turtles (Chelodina longicollis) from individual capture–recapture records spanning periods of up to 17 years for a population in Gippsland, Victoria, close to the high-latitude end of the species’ natural range. Juvenile growth was rapid and similar among individuals but adult growth was usually slow, highly variable among individuals and erratic within individuals over time. In addition, asymptotic body lengths were disparate among individuals for both males and females. Von Bertalanffy growth models fitted separately to males plus unsexed juveniles and females plus unsexed juveniles performed better than logistic models but tended to underestimate growth rates for very small and very large turtles and overestimate growth for medium-sized individuals. Sexual maturity was estimated to be achieved at 10 years in males and 16 years in females, which is late compared with most estimates for other populations of C. longicollis and for other turtle species in south-eastern Australia. The high variability of individual growth in this population makes age estimation from body size unreliable beyond the first few years of life.

scholarly journals A review of crack growth models for near-neutral pH stress corrosion cracking on oil and gas pipelines

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Haotian Sun ◽  
Wenxing Zhou ◽  
Jidong Kang
Keyword(s):  
Stress Corrosion ◽  
Crack Growth ◽  
Stress Corrosion Cracking ◽  
Growth Rates ◽  
Oil And Gas ◽  
Predictive Accuracy ◽  
Growth Models ◽  
Oil And Gas Pipelines ◽  
S Model ◽  
Crack Growth Rates

AbstractThis paper presents a review of four existing growth models for near-neutral pH stress corrosion cracking (NNpHSCC) defects on buried oil and gas pipelines: Chen et al.’s model, two models developed at the Southwest Research Institute (SwRI) and Xing et al.’s model. All four models consider corrosion fatigue enhanced by hydrogen embrittlement as the main growth mechanism for NNpHSCC. The predictive accuracy of these growth models is investigated based on 39 crack growth rates obtained from full-scale tests conducted at the CanmetMATERIALS of Natural Resources Canada of pipe specimens that are in contact with NNpH soils and subjected to cyclic internal pressures. The comparison of the observed and predicted crack growth rates indicates that the hydrogen-enhanced decohesion (HEDE) component of Xing et al.’s model leads to on average reasonably accurate predictions with the corresponding mean and coefficient of variation (COV) of the observed-to-predicted ratios being 1.06 and 61.2%, respectively. The predictive accuracy of the other three models are markedly poorer. The analysis results suggest that further research is needed to improve existing growth models or develop new growth models to facilitate the pipeline integrity management practice with respect to NNpHSCC.

scholarly journals An Overview of Population Growth Trends of Nepal

2015 ◽  
Vol 19 (1) ◽  
pp. 57-61 ◽  
Author(s):  
Laxman Kumar Regmi
Keyword(s):  
Population Growth ◽  
Growth Model ◽  
Growth Rates ◽  
Exponential Growth ◽  
Rural Areas ◽  
Population Change ◽  
Population Policy ◽  
Growth Models ◽  
Growth Trends ◽  
Time Period

This paper aims to estimate population growth rates of Nepal and also to estimate required time period for doubling population. For this, arithmetic, geometric and exponential growth models are applied. The data are taken from the recent national censuses of Nepal. Population growth trends were 2.10% in 1971, 2.60% in 1981, 2.10% in 1991, 2.25% in 2001 and 1.35% annually in 2011. The trends of urban populations were about 4% in 1971, 6% in 1981, 9% in 1991, 14% in 2001 and 17% in 2011. The population density rose from 79 in 1971 to 181 in 2011. Urban growth rate was 7% whereas it was 2% for rural areas. The population change was found to be 40% in urban whereas 11% in rural areas during 2001-2011. However, overall change was found to be 14% during 2001-2011. The estimated growth rates were found to be 1.44%, 1.35% and 1.35% by using arithmetic, geometric and exponential respectively. The estimated time period for doubling populations was found to be 67 year by arithmetic growth model and 50 years by geometric and exponential growth model. The findings of this paper may help policy-makers and planners for designing population policy of Nepal.Journal of Institute of Science and Technology, 2014, 19(1): 52-61

Sign in / Sign up

Export Citation Format

Share Document