scholarly journals Responses in population growth and reproduction of the freshwater rotiferBrachionus calyciflorusto microcystin-LR at different temperatures

2012 ◽  
Vol 48 (4) ◽  
pp. 383-390 ◽  
Author(s):  
Lin Huang ◽  
Yilong Xi ◽  
Xiaoping Xu ◽  
Xinli Wen
Keyword(s):  
Population Growth ◽  
Different Temperatures ◽  
Growth And Reproduction

Effects of the antibiotic tetracycline on the reproduction, growth and population growth rate of the nematode Caenorhabditis elegans

Nematology ◽  
2014 ◽  
Vol 16 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Matthew Vangheel ◽  
Walter Traunspurger ◽  
Nicole Spann
Keyword(s):  
Growth Rate ◽  
Caenorhabditis Elegans ◽  
Population Growth ◽  
Surface Waters ◽  
Population Growth Rate ◽  
Significant Risk ◽  
Protein Synthesis Inhibitors ◽  
Natural Systems ◽  
C Elegans ◽  
Growth And Reproduction

The antibiotic tetracycline (TC) has been reported in natural systems, a consequence of its abundant usage in farming. TCs are protein synthesis inhibitors that are effective against bacteria but adverse effects on non-target organisms, whilst less well understood, have also been demonstrated. This study is the first investigation into the effects of this common antibiotic on the growth, reproduction and population growth rate (PGR) of the nematode Caenorhabditis elegans. All toxicological endpoints were shown to be affected negatively. TC concentrations as low as 5 mg l−1 (5 ppm) significantly reduced growth and reproduction, and even lower concentrations (3 mg l−1 or 3 ppm) significantly decreased the PGR. These levels are much higher than the TC concentrations detected in surface waters, sediments and soils (0.005-300 ppb). However, although the antibiotic might not pose a direct significant risk to nematodes in the natural environment, its use in RNAi experiments involving C. elegans may cause unwanted effects that influence interpretations of the results.

Population Growth and Reproduction in Sub-Saharan Africa: Technical Analyses of Fertility and Its Consequences.

1991 ◽  
Vol 17 (2) ◽  
pp. 351
Author(s):  
[Geoffrey McNicoll] ◽  
George T. F. Acsadi ◽  
Gwendolyn Johnson-Acsadi ◽  
Rodolfo A. Bulatao
Keyword(s):  
Population Growth ◽  
Sub Saharan Africa ◽  
Sub Saharan ◽  
Growth And Reproduction

Estimation of population growth for two species of lady beetles (Coleoptera: Coccinellidae) under different temperatures

2021 ◽  
pp. 1-16
Author(s):  
Cynara Moura de Oliveira ◽  
Christian Sherley Araújo da Silva Torres ◽  
Jorge Braz Torres ◽  
Géssica dos Santos Silva
Keyword(s):  
Population Growth ◽  
Lady Beetles ◽  
Different Temperatures

Sensitivity and elasticity analysis of Tetranychus urticae Koch population parameters: Consequences for pest management 

2020 ◽  
Vol 25 (2) ◽  
pp. 268-284
Author(s):  
Alireza Nemati ◽  
Elham Riahi ◽  
Saadollah Houshmand
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Matrix Models ◽  
Survival Rates ◽  
Demographic Variables ◽  
Adult Survival ◽  
Egg Survival ◽  
Horticultural Crops ◽  
Structured Matrix ◽  
Different Temperatures

Sensitivity and elasticity analyses quantify the effect of an absolute and proportional change in demographic variables on population growth rate (λ), respectively. The methods are used to identify the variable(s) that have the largest influence on λ. Tetranychus urticae Koch is one of the most polyphagous tetranychid mites which has been collected from plenty plant species including agricultural and horticultural crops. In this study, sensitivity and elasticity analyses were used to investigate the effects of various demographic variables on λ at five different temperatures (15, 20, 25, 30 and 35 °C), using both age- and stage-structured matrix models. Considering the sensitivity of λ to age-dependent fecundity rates (fx), it was found that starting oviposition one day earlier was associated with the highest sensitivity compared to the other age classes, irrespective of temperature. Besides, results from both age- and stage-structured matrix models indicated that λ is more sensitive to changes in survival rates than in fecundity rates at all temperatures. Furthermore, female individuals at the ages of 46, 23, 14, 11 and 7 days had the highest contribution to population growth in comparison with other ages, when reared at the above-mentioned temperatures, respectively. Also, the sensitivity of λ to the changes in survival of adults was higher than in other stages. Besides, the elasticity to fecundity rate at the age of first reproduction was considerably higher than those associated with the age of last reproduction. The survival rates (si) generally exhibited a higher elasticity than the transition rates (gi). Overall, adult survival had the highest influence on λ followed by immature survival, egg survival, and female fecundity. Consequently, management efforts that aim at decreasing adult survival are likely to yield the best results with regard to reducing the growth rate of T. urticae.

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