scholarly journals Genetic Evaluation of Stillbirth in United States Holsteins Using a Sire-Maternal Grandsire Threshold Model

2007 ◽  
Vol 90 (5) ◽  
pp. 2480-2488 ◽  
Author(s):  
J.B. Cole ◽  
G.R. Wiggans ◽  
P.M. VanRaden
Keyword(s):  
United States ◽  
Threshold Model ◽  
Genetic Evaluation ◽  
Maternal Grandsire

scholarly journals WHEN DO CITIZENS TAKE COSTLY ACTION AGAINST GOVERNMENT CORRUPTION? EVIDENCE FROM EXPERIMENTS IN AUSTRALIA, SINGAPORE, AND THE UNITED STATES

2017 ◽  
Vol 17 (1) ◽  
pp. 119-136 ◽  
Author(s):  
O. Fiona Yap
Keyword(s):  
United States ◽  
Collective Action ◽  
Threshold Model ◽  
The United States ◽  
Empirical Literature ◽  
Theoretical Argument ◽  
Policy Debates ◽  
Government Corruption ◽  
Survey Experiments ◽  
Stag Hunt Game

AbstractWhen do citizens take costly collective action against government corruption? When citizens act in concert, their demands are credible and not easily discounted by governments, which should be more likely to respond. In this study, we use the stag-hunt game, supplemented by Granovetter's threshold model of collective action, to investigate the conditions under which citizens coordinate to collectively act against government corruption. We use survey experiments in laboratory settings in Australia, Singapore, and the United States. The results show several conditions motivate participants to pursue collective action; using the wellspring of the theoretical argument, they clarify that information that others pursue collective action, together with clear mutual benefits as measured by rewards, are primary motivators of the individual's choice. Correspondingly, other considerations, including initial costs or final potential penalties, do not bear on the individual's choice. The findings have implications not only for the empirical literature on policy but also for policy debates on how to control it.

scholarly journals Threshold models for the determination of genetic variability among reproductive traits in Nellore cattle

2020 ◽  
Vol 55 ◽  
Author(s):  
Leonardo Martin Nieto ◽  
Luiz Otávio Campos da Silva ◽  
Antônio do Nascimento Ferreira Rosa
Keyword(s):  
Genetic Variability ◽  
Threshold Model ◽  
Reproductive Traits ◽  
Threshold Models ◽  
Multiple Trait ◽  
Bayesian Procedures ◽  
Nellore Cattle ◽  
Heritability Estimates ◽  
Maternal Grandsire

Abstract: The objective of this work was to evaluate the potential of different threshold models to determine the genetic variability in Nellore cattle, with basis on the heritability estimates for the traits stayability (STA) and first calving probability at 36 months of age (CP36). Data came from the Nellore herds participating in the animal breeding program of the Embrapa-Geneplus partnership. Binomial and multi-threshold models were defined for the STA and CP36 traits. Heritability estimates were obtained following Bayesian procedures in the Multiple-trait Gibbs Sampler for Animal Models (MTGSAM) software, using a sire-maternal grandsire model. The heritability estimates, provided by the binary and alternative models, were, respectively, 0.08 and 0.12 for STA and 0.17 and 0.12 for CP36. The multi-threshold model can efficiently detect the genetic variability for stayability, but not for probability of calving for 36-month-old cows.

Some factors affecting the estimation of genetic parameters for cattle dystocia under a threshold model

1991 ◽  
Vol 53 (2) ◽  
pp. 151-156 ◽  
Author(s):  
E. J. Manfredi ◽  
M. San Cristobal ◽  
J. L. Foulley
Keyword(s):  
Maternal Effects ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
Threshold Model ◽  
Genetic Parameter ◽  
Random Effect ◽  
Large Data ◽  
Marginal Maximum Likelihood ◽  
Factors Affecting ◽  
Maternal Grandsire

AbstractGenetic parameters for dystocia in the Main-Anjou breed were estimated. Data consisted of 28 178 birth records collected between 1978 and 1989 in 995 herds, with 161, 71 and 12 415 sires, maternal grandsires and dams, respectively, represented. Original scores (1 through 5) were collapsed in order to set two dystocia definitions: dystocia 1 (scores 1+2 v. 3+4+5) and dystocia 2 (scores 1 v. 2+3+4+5). Four models were proposed for genetic parameter estimation: (1) fixed effects plus sire effects; (2) model 1 plus maternal grandsire effect; (3) model 2 plus dam within maternal grandsire effects; (4) same as model 3 but a random effect ‘herds’ replaced a fixed effect ‘regions’. Two methods of fitting models were applied: marginal maximum likelihood and the ‘tilde-hat’ approach. Estimates of genetic parameters by the two methods were similar. Models ignoring maternal effects overestimated the heritability of direct effects especially in the case of dystocia 2. Dystocia definition was responsible for the greatest difference among estimated genetic parameters. Possible reasons for this are discussed. When analysing large data sets, it is recommended judiciously to collapse dystocia categories and to apply approximate statistical procedures to complete models including maternal effects.

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