Search

Your search keyword '"Donahue, James L."' showing total 15 results
Start Over Author "Donahue, James L."
15 results on '"Donahue, James L."'

1. Nonlinear social evolution and the emergence of collective action

Author

Allen, Benjamin, Khwaja, Abdur-Rahman, Donahue, James L., Lattanzio, Cassidy, Dementieva, Yulia A., and Sample, Christine

Subjects
Quantitative Biology - Populations and Evolution, 92D15, 91A22
Abstract

Organisms from microbes to humans engage in a variety of social behaviors, which affect fitness in complex, often nonlinear ways. The question of how these behaviors evolve has consequences ranging from antibiotic resistance to human origins. However, evolution with nonlinear social interactions is challenging to model mathematically, especially in combination with spatial, group, and/or kin assortment. We derive a mathematical condition for natural selection with synergistic interactions among any number of individuals. This result applies to populations with arbitrary (but fixed) spatial or network structure, group subdivision, and/or mating patterns. In this condition, nonlinear fitness effects are ascribed to collectives, and weighted by a new measure of collective relatedness. For weak selection, this condition can be systematically evaluated by computing branch lengths of ancestral trees. We apply this condition to pairwise games between diploid relatives, and to dilemmas of collective help or harm among siblings and on spatial networks. Our work provides a rigorous basis for extending the notion of ``actor", in the study of social evolution, from individuals to collectives., Comment: 12 page main text, with 72 page Supplementary Information. Published in PNAS Nexus. Previously posted as a preprint entitled "Natural selection for collective action"

Published
2023
Full Text
View/download PDF

3. Natural selection for collective action

Author

Allen, Benjamin, Khwaja, Abdur-Rahman, Donahue, James L., Lattanzio, Cassidy, Dementieva, Yulia A., and Sample, Christine

Subjects
92D15, 91A22, FOS: Biological sciences, Populations and Evolution (q-bio.PE), Quantitative Biology - Populations and Evolution
Abstract

Collective action -- behavior that arises from the combined actions of multiple individuals -- is observed across living beings. The question of how and why collective action evolves has profound implications for behavioral ecology, multicellularity, and human society. Collective action is challenging to model mathematically, due to nonlinear fitness effects and the consequences of spatial, group, and/or family relationships. We derive a simple condition for collective action to be favored by natural selection. A collective's effect on the fitness of each individual is weighted by the relatedness between them, using a new measure of collective relatedness. If selection is weak, this condition can be evaluated using coalescent theory. More generally, our result applies to any synergistic social behavior, in spatial, group, and/or family-structured populations. We use this result to obtain conditions for the evolution of collective help among diploid siblings, subcommunities of a network, and hyperedges of a hypergraph. We also obtain a condition for which of two strategies is favored in a game between siblings, cousins, or other relatives. Our work provides a rigorous basis for extending the notion of ``actor", in the study of social behavior, from individuals to collectives., Comment: 86 pages, 9 figures

Published
2023
Full Text
View/download PDF

7. A comparative analysis of international encryption policies en route to a domestic solution

Author

Donahue, James L., Huntley, Wade, Simeral, Robert, and National Security Affairs (NSA)

Subjects
lawful hacking, cell phone, China, device encryption, data at rest, Fourth Amendment, going dark, exceptional access, Israel, encryption
Abstract

This thesis examines the encryption policies of Israel and China in an effort to determine whether their respective approaches effectively and reasonably address the issue of law enforcement access to encrypted devices in the United States. The proliferation of encrypted devices poses a growing challenge to law enforcement agencies in their efforts to gather evidence. Meanwhile, an ongoing debate, decades in the making, persists between those arguing for and against easing the means by which the government accesses these encrypted devices. Using qualitative analysis, the thesis assesses the encryption policies of Israel and China in terms of legality, cost, political acceptance, and potential for success in their application within the United States. Based on this analysis, this thesis recommends policymakers give consideration to a solution that resembles Israel’s approach. The characteristics of this model include creating, under existing laws, a centralized forensic laboratory supported by a network of examiners located across the country working to gain access to encrypted devices through vulnerabilities. These efforts would be bolstered by relationships with the private sector and academia. Tailoring the U.S. device encryption approach to be more consistent in structure with that of Israel has the potential to bring the United States closer to a viable domestic solution. http://archive.org/details/acomparativenaly1094558291 Assistant to the Special Agent in Charge, United States Secret Service, Richmond Field Office, Richmond, Virginia Approved for public release; distribution is unlimited.

Published
2018

9. A comparative analysis of international encryption policies en route to a domestic solution

Author

Huntley, Wade, Simeral, Robert, National Security Affairs (NSA), Donahue, James L., Huntley, Wade, Simeral, Robert, National Security Affairs (NSA), and Donahue, James L.

Abstract

This thesis examines the encryption policies of Israel and China in an effort to determine whether their respective approaches effectively and reasonably address the issue of law enforcement access to encrypted devices in the United States. The proliferation of encrypted devices poses a growing challenge to law enforcement agencies in their efforts to gather evidence. Meanwhile, an ongoing debate, decades in the making, persists between those arguing for and against easing the means by which the government accesses these encrypted devices. Using qualitative analysis, the thesis assesses the encryption policies of Israel and China in terms of legality, cost, political acceptance, and potential for success in their application within the United States. Based on this analysis, this thesis recommends policymakers give consideration to a solution that resembles Israel’s approach. The characteristics of this model include creating, under existing laws, a centralized forensic laboratory supported by a network of examiners located across the country working to gain access to encrypted devices through vulnerabilities. These efforts would be bolstered by relationships with the private sector and academia. Tailoring the U.S. device encryption approach to be more consistent in structure with that of Israel has the potential to bring the United States closer to a viable domestic solution.

Published
2018

10. Clinical evaluation of resin-bonded bridges: a retrospective study.

Author

Olin, Paul S., Hill, Elaine M. E., and Donahue, James L.

Subjects
BRIDGES (Dentistry), DENTAL resins, DENTAL bonding, DENTAL fillings, DENTAL arch, PROSTHODONTICS, PERIODONTAL splints, DENTISTRY, DENTAL enamel
Abstract

Eight-five patients with a total of 103 resin-bonded bridges placed by practitioners at the University of Minnesota School of Dentistry between 1982 and 1989 were recalled for a clinical evaluation of their restorations. Tissue condition, patient satisfaction, bridge failures by location and by sex of patient, and average length of service for both successful and failed bridges were recorded. After an average service of 3.25 years, 12.6% of the fixed partial dentures had debonded. Debondings occurred most frequently in the mandibular arch. Failures occurred more frequently in men than in women, and prostheses with more than two retainers had twice the probability for problems. [ABSTRACT FROM AUTHOR]

Published
1991

14. A comparative analysis of international encryption policies en route to a domestic solution

Author

Huntley, Wade, Simeral, Robert, National Security Affairs (NSA), Donahue, James L., Huntley, Wade, Simeral, Robert, National Security Affairs (NSA), and Donahue, James L.

Abstract

This thesis examines the encryption policies of Israel and China in an effort to determine whether their respective approaches effectively and reasonably address the issue of law enforcement access to encrypted devices in the United States. The proliferation of encrypted devices poses a growing challenge to law enforcement agencies in their efforts to gather evidence. Meanwhile, an ongoing debate, decades in the making, persists between those arguing for and against easing the means by which the government accesses these encrypted devices. Using qualitative analysis, the thesis assesses the encryption policies of Israel and China in terms of legality, cost, political acceptance, and potential for success in their application within the United States. Based on this analysis, this thesis recommends policymakers give consideration to a solution that resembles Israel’s approach. The characteristics of this model include creating, under existing laws, a centralized forensic laboratory supported by a network of examiners located across the country working to gain access to encrypted devices through vulnerabilities. These efforts would be bolstered by relationships with the private sector and academia. Tailoring the U.S. device encryption approach to be more consistent in structure with that of Israel has the potential to bring the United States closer to a viable domestic solution., http://archive.org/details/acomparativenaly1094558291, Assistant to the Special Agent in Charge, United States Secret Service, Richmond Field Office, Richmond, Virginia, Approved for public release; distribution is unlimited.

15. The Effects of Aging and Endurance Exercise on Cardiovascular Performance in Healthy Elderly: A Review of the Literature.

Author

Cherubini A, Donahue JL, Lowenthal DT, Mecocci P, Meuleman JR, Maggio D, and Senin U

Abstract

CV performance declines over time in healthy elderly subjects due to aging, as well as declining physical activity. Recent studies with older, often sedentary individuals, demonstrate that aerobic endurance exercise may improve several measures of CV function. Although further research is needed to characterize the CV effects of exercise, particularly in elderly women and the oldest old population, aerobic endurance exercise should be advocated in the healthy elderly.

Published
1998

Catalog

Books, media, physical & digital resources
See catalog results