scholarly journals A simplified age-stage model for copepod population dynamics

2008 ◽  
Vol 360 ◽  
pp. 179-187 ◽  
Author(s):  
Q Hu ◽  
CS Davis ◽  
CM Petrik
Keyword(s):  
Population Dynamics ◽  
Stage Model ◽  
Copepod Population

Modeling population dynamics and nonstationary processes of difficult-to-age fishery species with a hierarchical Bayesian two-stage model

2019 ◽  
Vol 76 (12) ◽  
pp. 2199-2214 ◽  
Author(s):  
Yan Li ◽  
Laura M. Lee ◽  
Jason Rock
Keyword(s):  
North Carolina ◽  
Population Dynamics ◽  
Natural Mortality ◽  
Hierarchical Bayesian ◽  
Stage Model ◽  
Survey Analysis ◽  
Two Stage ◽  
The North ◽  
Fishery Species

Modeling population dynamics and establishing a comprehensive population assessment for fishery species that are difficult to age have been challenging. Determination of age for such species is still an unresolved issue or is at best uncertain. Catch-survey analysis does not require full age information but can still provide a comprehensive population assessment. It was extended to incorporate multiple surveys and multiple sources of uncertainties within the statistical catch-at-age framework in the applications to crustaceans. Here, we further generalize and extend the multiple survey catch-survey analysis into a hierarchical Bayesian two-stage model by applying the hierarchical Bayesian approach. The hierarchical Bayesian approach can sufficiently incorporate uncertainty and expert opinions in parameter estimation. We developed a series of models with different assumptions for natural mortality and catchability, including nonstationary (i.e., time-varying) assumptions. We evaluated model robustness to these assumptions and compared population dynamics estimates and population status determination. We demonstrated the application of the hierarchical Bayesian two-stage model using the North Carolina blue crab (Callinectes sapidus) example. In this example, estimation of population size and fishing mortality and determination of population status were robust to the natural mortality and catchability assumptions. The North Carolina blue crab population is less likely to have nonstationary catchability or nonstationary natural mortality. Its natural mortality is more likely to vary by stage than by sex or over time.

Influence of LAS on marine calanoid copepod population dynamics and potential reproduction

2003 ◽  
Vol 63 (4) ◽  
pp. 405-416 ◽  
Author(s):  
Kirsten Christoffersen ◽  
Benni W. Hansen ◽  
Liselotte S. Johansson ◽  
Elisabeth Krog
Keyword(s):  
Population Dynamics ◽  
Calanoid Copepod ◽  
Copepod Population

scholarly journals Estimation techniques used in studies of copepod population dynamics — A review of underlying assumptions

Sarsia ◽  
1997 ◽  
Vol 82 (4) ◽  
pp. 279-296 ◽  
Author(s):  
Dag L. Aksnes ◽  
Charles B. Miller ◽  
Mark D. Ohman ◽  
Simon N. Wood
Keyword(s):  
Population Dynamics ◽  
Estimation Techniques ◽  
Copepod Population

The Solution Strategy as an Indicator of the Developmental Stage of Preschool Children’s Mental-Rotation Ability

2010 ◽  
Vol 31 (2) ◽  
pp. 95-100 ◽  
Author(s):  
Claudia Quaiser-Pohl ◽  
Anna M. Rohe ◽  
Tobias Amberger
Keyword(s):  
Preschool Children ◽  
Mental Rotation ◽  
Latent Class ◽  
Preschool Age ◽  
Stage Model ◽  
Solution Strategy ◽  
Thinking Aloud ◽  
Transition Analysis ◽  
Solution Strategies ◽  
Close Relationship

The solution strategies of preschool children solving mental-rotation tasks were analyzed in two studies. In the first study n = 111 preschool children had to demonstrate their solution strategy in the Picture Rotation Test (PRT) items by thinking aloud; seven different strategies were identified. In the second study these strategies were confirmed by latent class analysis (LCA) with the PRT data of n = 565 preschool children. In addition, a close relationship was found between the solution strategy and children’s age. Results point to a stage model for the development of mental-rotation ability as measured by the PRT, going from inappropriate strategies like guessing or comparing details, to semiappropriate approaches like choosing the stimulus with the smallest angle discrepancy, to a holistic or analytic strategy. A latent transition analysis (LTA) revealed that the ability to mentally rotate objects can be influenced by training in the preschool age.

Timing of repeated movements: Test of a two-stage model

1997 ◽  
Author(s):  
Saul Sternberg ◽  
Teresa Pantzer
Keyword(s):  
Stage Model ◽  
Two Stage
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