Estimating the Population Dynamics of Coho Salmon (Oncorhynchus kisutch) Using Pooled Time-Series and Cross-Sectional Data

1985 ◽  
Vol 42 (3) ◽  
pp. 459-467 ◽  
Author(s):  
James L. Anderson ◽  
James E. Wilen
Keyword(s):  
Time Series ◽  
Population Dynamics ◽  
River Flow ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Cross Sectional ◽  
Factors Affecting ◽  
River Region ◽  
Parent Stock ◽  
Pooled Time Series

The population dynamics of natural and hatchery coho salmon (Oncorhynchus kisutch) were estimated for three regions, (1) Washington coastal, (2) Columbia River region, and (3) Oregon/California coastal, using pooled time-series and cross-sectional data. Two functional forms were compared: the Beverton–Holt and Ricker models. Both models yielded very similar results. In both cases, we found that the natural coho stock recruitment is significantly affected by parent stock level (positive), parent stock density (negative), river flow (positive), and hatchery smolt release (negative). The significant factors affecting hatchery coho salmon were smolt release level (positive), smolt release density (negative), and upwelling (positive).

Free Traders and Drug Smugglers: The Effects of Trade Openness on States' Ability to Combat Drug Trafficking

2009 ◽  
Vol 51 (2) ◽  
pp. 117-145 ◽  
Author(s):  
Horace A. Bartilow ◽  
Kihong Eom
Keyword(s):  
Time Series ◽  
Statistical Model ◽  
Drug Trafficking ◽  
Trade Openness ◽  
Cross Sectional ◽  
Theoretical Literature ◽  
Openness To Trade ◽  
Pooled Time Series

AbstractThe theoretical literature presents conflicting expectations about the effects of trade openness on the ability of states to interdict drug trafficking. One view expects that trade openness will undermine drug interdiction; a second argues the opposite; a third argues that trade openness does not necessarily affect drug interdiction. This article assesses empirically the effects of trade openness on drug interdiction for countries in the Americas using a pooled time-series cross-sectional statistical model. It finds that trade openness decreases the interdiction capabilities of states in drug-consuming countries while increasing those of states in drug-producing countries. Greater openness to trade does not have a consistently significant effect on the interdiction capabilities of states in drug transit countries.

Metrics and sampling designs for detecting trends in the distribution of spawning Pacific salmon (Oncorhynchus spp.)

2012 ◽  
Vol 69 (4) ◽  
pp. 681-694 ◽  
Author(s):  
Stephanie J. Peacock ◽  
Carrie A. Holt
Keyword(s):  
Population Dynamics ◽  
Environmental Variability ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Oncorhynchus Kisutch ◽  
Sensitivity Analyses ◽  
Observation Error ◽  
Simulated Population ◽  
Age At Maturity ◽  
Status Assessment

The distribution of individuals among populations and in space may contribute to their resilience under environmental variability. Changes in distribution may indicate the loss of genetically distinct subpopulations, the deterioration of habitat capacity, or both. The distribution of Pacific salmon ( Oncorhynchus  spp.) among spawning locations has recently been recognized as an important component of status assessment by USA and Canadian management agencies, but metrics of spawning distribution have not been rigorously evaluated. We evaluated three metrics of spawning distribution and four sampling designs for their ability to detect simulated contractions in the production of coho salmon ( Oncorhynchus kisutch ). We simulated population dynamics at 100 sites using a spawner–recruit model that incorporated natural variability in recruitment, age-at-maturity, dispersal, and measurement error in observations of abundance. Sensitivity analyses revealed that high observation error and straying of spawners from their natal streams may mask changes in distribution. Furthermore, monitoring only sites with high spawner abundance, as is often practiced, failed to capture the simulated contraction of production, emphasizing the importance of matching monitoring programs with assessment objectives.

Corn Acreage Response‐Function Estimation with Pooled Time‐Series and Cross‐Sectional Data

1979 ◽  
Vol 61 (3) ◽  
pp. 551-553 ◽  
Author(s):  
James K. Whittaker ◽  
Robert L. Bancroft
Keyword(s):  
Time Series ◽  
Response Function ◽  
Function Estimation ◽  
Cross Sectional ◽  
Response Function Estimation ◽  
Pooled Time Series

The Factors Affecting Airspace Capacity in Europe: A Cross-Sectional Time-Series Analysis Using Simulated Controller Workload Data

2004 ◽  
Vol 57 (3) ◽  
pp. 385-405 ◽  
Author(s):  
Arnab Majumdar ◽  
Washington Y. Ochieng ◽  
Gérard McAuley ◽  
Jean Michel Lenzi ◽  
Catalin Lepadatu
Keyword(s):  
Time Series ◽  
Time Series Analysis ◽  
Capacity Planning ◽  
Air Traffic ◽  
Parameter Estimates ◽  
Peak Period ◽  
Cross Sectional ◽  
Factors Affecting ◽  
Series Analysis ◽  
Centre Region

Air traffic in Europe is increasing at a rapid rate and traffic patterns no longer display pronounced daily peaks but instead exhibit peak spreading. Airspace capacity planning can no longer be for the peak period but must consider the whole day. En route airspace capacity in the high density European air traffic network is determined by controller workload. Controller workload is primarily affected by the features of the air traffic and ATC sector. This paper considers the air traffic and ATC sector factors that affect controller workload throughout the whole day. A simulation study using the widely used Reorganized ATC Mathematical Simulator (RAMS) model of air traffic controller workload is conducted for the Central European Air Traffic Services (CEATS) Upper Area Control Centre region of Europe. A cross-sectional time series analysis of the simulation output is conducted with corrections for temporal autocorrelation in the data. The results indicate that a subset of traffic and sector variables and their parameter estimates can be used to predict controller workload in any sector of the CEATS region in any given hour.

Spatial and temporal factors affecting survival in coho salmon (Oncorhynchus kisutch) in the Pacific Northwest

1998 ◽  
Vol 55 (9) ◽  
pp. 2067-2077 ◽  
Author(s):  
Claribel Coronado ◽  
Ray Hilborn
Keyword(s):  
British Columbia ◽  
Pacific Northwest ◽  
Coho Salmon ◽  
Survival Rates ◽  
Oncorhynchus Kisutch ◽  
Dominant Factor ◽  
Spatial And Temporal Patterns ◽  
Factors Affecting ◽  
The Pacific ◽  
Ocean Conditions

Survival rates for coho salmon (Oncorhynchus kisutch) were estimated for all coded wire tag release groups in the Pacific Northwest between 1971 and 1990. The spatial and temporal patterns show considerable geographic variation, with most regions south of northern British Columbia showing declining survival since 1983, while northern areas have shown increasing survival during that period. The number of years of operation explained very little of the variation in survival, and many hatcheries showed major increases in survival after several years of operation. Survival of marked wild fish generally showed the same trend as hatchery fish. We conclude that the dominant factor affecting coho salmon survival since the 1970s is ocean conditions and that there are major geographic differences in the pattern of ocean conditions. The decline in survival seen in British Columbia and south over the last decade suggests that a major reduction in exploitation rates is necessary to maintain the populations.

Three-Dimensional Prey Reaction Field of the Juvenile Coho Salmon (Oncorhynchus kisutch)

1984 ◽  
Vol 41 (8) ◽  
pp. 1176-1182 ◽  
Author(s):  
Robert L. Dunbrack ◽  
Lawrence M. Dill
Keyword(s):  
Feeding Behaviour ◽  
Coho Salmon ◽  
Three Dimensional ◽  
Oncorhynchus Kisutch ◽  
Cross Sectional ◽  
Simple Method ◽  
Reaction Field ◽  
Scanning Area ◽  
In The Wild ◽  
Distribution Of Points

Filmed observations of the feeding behaviour of juvenile coho salmon (Oncorhynchus kisutch) cruising in a large aquarium were used to determine the three-dimensional shape of their reaction field, and to estimate the cross-sectional area of the effective volume searched for prey (scanning area). Reaction distance was greatest above the horizontal visual plane and ahead of the transverse visual plane, and this corresponds to the feeding behaviour of fish observed in the wild. The scanning area for a given size of prey was obtained by plotting all captures as projections on the transverse plane. This distribution of points was then divided into a series of concentric bands characterized by prey attack probabilities, which were then used as weighting factors in the final calculation of the scanning area. Our results and techniques are discussed in relation to previous studies of fish reaction fields, and a simple method of estimating scanning area for salmonids is suggested.

Applying time series models with spatial correlation to identify the scale of variation in habitat metrics related to threatened coho salmon (Oncorhynchus kisutch) in the Pacific Northwest

2012 ◽  
Vol 69 (11) ◽  
pp. 1773-1782 ◽  
Author(s):  
Eric J. Ward ◽  
George R. Pess ◽  
Kara Anlauf-Dunn ◽  
Chris E. Jordan
Keyword(s):  
Time Series ◽  
Spatial Correlation ◽  
Pacific Northwest ◽  
Coho Salmon ◽  
Spatial Scales ◽  
Oncorhynchus Kisutch ◽  
Fine Sediment ◽  
Environmental Stochasticity ◽  
Observation Error ◽  
Data Set

Trend analyses are common in the analysis of fisheries data, yet the majority of them ignore either observation error or spatial correlation. In this analysis, we applied a novel hierarchical Bayesian state-space time series model with spatial correlation to a 12-year data set of habitat variables related to coho salmon ( Oncorhynchus kisutch ) in coastal Oregon, USA. This model allowed us to estimate the degree of spatial correlation separately for each habitat variable and the importance of observation error relative to environmental stochasticity. This framework allows us to identify variables that would benefit from additional sampling and variables where sampling could be reduced. Of the eight variables included in our analysis, we found three metrics related to habitat quality correlated at large spatial scales (gradient, fine sediment, shade cover). Variables with higher observation error (pools, active channel width, fine sediment) could be made more precise with more repeat visits. Our spatio-temporal model is flexible and extendable to virtually any spatially explicit monitoring data set, even with large amounts of missing data and no repeated observations. Potential extensions include fisheries catch data, abiotic indicators, invasive species, or species of conservation concern.

Application of cross-sectional time series modeling for the prediction of energy expenditure from heart rate and accelerometry

2008 ◽  
Vol 104 (6) ◽  
pp. 1665-1673 ◽  
Author(s):  
Issa Zakeri ◽  
Anne L. Adolph ◽  
Maurice R. Puyau ◽  
Firoz A. Vohra ◽  
Nancy F. Butte
Keyword(s):  
Heart Rate ◽  
Time Series ◽  
Energy Expenditure ◽  
Children And Adolescents ◽  
Dynamic Models ◽  
Specific Model ◽  
Accurate Estimation ◽  
Cross Sectional ◽  
Factors Affecting ◽  
Random Slopes

Accurate estimation of energy expenditure (EE) in children and adolescents is required for a better understanding of physiological, behavioral, and environmental factors affecting energy balance. Cross-sectional time series (CSTS) models, which account for correlation structure of repeated observations on the same individual, may be advantageous for prediction of EE. CSTS models for prediction of minute-by-minute EE and, hence, total EE (TEE) from heart rate (HR), physical activity (PA) measured by accelerometry, and observable subject variables were developed in 109 children and adolescents by use of Actiheart and 24-h room respiration calorimetry. CSTS models based on HR, PA, time-invariant covariates, and interactions were developed. These dynamic models involve lagged and lead values of HR and lagged values of PA for better description of the series of minute-by-minute EE. CSTS models with random intercepts and random slopes were investigated. For comparison, likelihood ratio tests were used. Log likelihood increased substantially when random slopes for HR and PA were added. The population-specific model uses HR and 1- and 2-min lagged and lead values of HR, HR2, and PA and 1- and 2-min lagged values of PA, PA2, age, age2, sex, weight, height, minimum HR, sitting HR, HR × height, HR × weight, HR × age, PA × weight, and PA × sex interactions ( P < 0.001). Prediction error for TEE was 0.9 ± 10.3% (mean ± SD). Errors were not correlated with age, weight, height, or body mass index. CSTS modeling provides a useful predictive model for EE and, hence, TEE in children and adolescents on the basis of HR and PA and other observable explanatory subject characteristics of age, sex, weight, and height.

Corporatism in Decline?

1992 ◽  
Vol 25 (2) ◽  
pp. 139-168 ◽  
Author(s):  
MARKUS M. L. CREPAZ
Keyword(s):  
Economic Growth ◽  
Time Series ◽  
Growth Rates ◽  
Macroeconomic Performance ◽  
Cross Sectional ◽  
Cross Sectional Analysis ◽  
Industrial Disputes ◽  
Sectional Analysis ◽  
Economic Growth Rates ◽  
Pooled Time Series

During the 1970s and early 1980s most studies on corporatism indicated that corporatist policies led to lower unemployment and inflation and higher economic growth rates. In the mid- and late 1980s, however, voices claiming that corporatism is in “decline” became more and more frequent although hardly any empirical examinations were undertaken. The purpose of this study is to estimate empirically the influence of corporatist arrangements on macroeconomic performance and industrial disputes in the 1980s as compared with the 1970s and 1960s. This pooled time-series/cross-sectional analysis provides evidence that corporatist policies have not lost their capacity to achieve the desired macroeconomic goals in the 1980s; in addition, corporatism significantly reduces the number of working days lost. However, no evidence was found that corporatism leads to increased economic growth. There is evidence that economic growth is adversely affected by government outlays.

The Dynamics of Orangeism in Scotland

2006 ◽  
Vol 30 (2) ◽  
pp. 263-292
Author(s):  
Eric Kaufmann
Keyword(s):  
Social Capital ◽  
Time Series ◽  
Voluntary Associations ◽  
Economic Structure ◽  
Cross Sectional ◽  
Competing Hypotheses ◽  
Sectional Model ◽  
Pooled Time Series ◽  
Orange Order ◽  
Intermediate Role

Like other voluntary associations, fraternities such as the Orange Order underpin political cleavages. The membership dynamics behind such associations are less clear. Rival theories attribute membership fluctuations alternatively to changes in social capital, economic structure, culture, or events. This article uses a pooled time-series cross sectional model to evaluate competing hypotheses for the period since 1860. Results suggest that membership was linked to longer-term shifts in ethnic boundaries rather than structural or social capital variables, with events playing an intermediate role. Scottish Protestant mobilization against Catholics was less important than Irish Protestant ethnicity, but both were key. Finally, the order has been numerically weaker than many believe; hence its inability—even during the apex of its influence—to shape Tory policy.

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