Daniel Twedt, Ph.D. (Former Employee)
Science and Products
Filter Total Items: 93
Comparison of algorithms for replacing missing data in discriminant analysis Comparison of algorithms for replacing missing data in discriminant analysis
We examined the impact of different methods for replacing missing data in discriminant analyses conducted on randomly generated samples from multivariate normal and non-normal distributions. The probabilities of correct classification were obtained for these discriminant analyses before and after randomly deleting data as well as after deleted data were replaced using: (1) variable means...
Authors
Daniel J. Twedt, D.S. Gill
Genetic variation in male Yellow-headed Blackbirds from the northern Great Plains Genetic variation in male Yellow-headed Blackbirds from the northern Great Plains
Electrophoretic differences at 15 presumptive loci were used to assess allelic frequencies, heterozygosities, and polymorphism for male Yellow-headed Blackbirds (Xanthocephalus xanthocephalus) collected in east-central Alberta, north-central North Dakota, and east-central South Dakota. Five loci were polymorphic and mean heterozygosities ranged from 0.119 to 0.133. Significant...
Authors
Daniel J. Twedt, William J. Bleier, George M. Linz
Geographic and temporal variation in the diet of Yellow-headed Blackbirds Geographic and temporal variation in the diet of Yellow-headed Blackbirds
Yellow-headed Blackbirds (Xanthocephalus xanthocephalus) are presumed predators of sunflower (Helianthus annuus) in the northern Great Plains. Their esophageal contents varied temporally and among three provinces and three states in relation to regional agricultural bases but males contained more sunflower and small grains than females whereas females contained more weed seeds and...
Authors
Daniel J. Twedt, William J. Bleier, George M. Linz
Science and Products
Filter Total Items: 93
Comparison of algorithms for replacing missing data in discriminant analysis Comparison of algorithms for replacing missing data in discriminant analysis
We examined the impact of different methods for replacing missing data in discriminant analyses conducted on randomly generated samples from multivariate normal and non-normal distributions. The probabilities of correct classification were obtained for these discriminant analyses before and after randomly deleting data as well as after deleted data were replaced using: (1) variable means...
Authors
Daniel J. Twedt, D.S. Gill
Genetic variation in male Yellow-headed Blackbirds from the northern Great Plains Genetic variation in male Yellow-headed Blackbirds from the northern Great Plains
Electrophoretic differences at 15 presumptive loci were used to assess allelic frequencies, heterozygosities, and polymorphism for male Yellow-headed Blackbirds (Xanthocephalus xanthocephalus) collected in east-central Alberta, north-central North Dakota, and east-central South Dakota. Five loci were polymorphic and mean heterozygosities ranged from 0.119 to 0.133. Significant...
Authors
Daniel J. Twedt, William J. Bleier, George M. Linz
Geographic and temporal variation in the diet of Yellow-headed Blackbirds Geographic and temporal variation in the diet of Yellow-headed Blackbirds
Yellow-headed Blackbirds (Xanthocephalus xanthocephalus) are presumed predators of sunflower (Helianthus annuus) in the northern Great Plains. Their esophageal contents varied temporally and among three provinces and three states in relation to regional agricultural bases but males contained more sunflower and small grains than females whereas females contained more weed seeds and...
Authors
Daniel J. Twedt, William J. Bleier, George M. Linz