140 research outputs found
The impact of sedentary and physical activity behavior on frailty in middle-aged and older adults
No full textPlease see attached file.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
A Volumetric Proof of the Log-Concavity of the Characteristic Polynomial of Matroids
No full textThis thesis presents a novel proof of the Heron–Rota–Welsh conjecture using a volume theoretic approach. Originating in the 1950's, the conjecture proposes that the coefficients of the characteristic polynomial of a matroid exhibit the property of log-concavity. A complete proof for all matroids was found only in 2018, when Jun Huh, in collaboration with Karim Adiprasito and Eric Katz, achieved this milestone by developing the theory of combinatorial Hodge theory. We review the link between the combinatorial data of matroids, algebraic objects known as Chow rings, and geometric objects called Bergman fans, and then outline the recent work of Dustin Ross, Anastasia Nathanson, Lauren Nowak, and the author on the theory of normal complexes of fans and their volumetric properties. Our main result stems from showing that the Bergman fans of matroids meet criteria such that the (extended) mixed volumes of their normal complexes obey the Alexandrov–Fenchel inequality, yielding log-concave sequences. We hope this demonstrates that the theory of normal complexes is a tool able to tackle modern problems in mathematics
Influences of host community characteristics on Borrelia burgdorferi infection prevalence in Blacklegged ticks
No full textLyme disease is a major vector-borne bacterial disease in the USA. The disease is caused by Borrelia burgdorferi, and transmitted among hosts and humans, primarily by blacklegged ticks (Ixodes scapularis). The ~25 B. burgdorferi genotypes, based on genotypic variation of their outer surface protein C (ospC), can be phenotypically separated as strains that primarily cause human diseases – human invasive strains (HIS) – or those that rarely do – and are non-randomly associated with host species. The goal of this study was to examine the extent to which phenotypic outcomes of B. burgdorferi could be explained by the host communities fed upon by blacklegged ticks. In 2006 and 2009, we determined the host community composition based on abundance estimates of the vertebrate hosts, and collected host-seeking nymphal ticks in 2007 and 2010 to determine the ospC genotypes within infected ticks. We regressed instances of B. burgdorferi phenotypes on site-specific characteristics of host communities by constructing Bayesian hierarchical models that properly handled missing data. The models provided quantitative support for the relevance of host composition on Lyme disease risk pertaining to B. burgdorferi prevalence (i.e., overall nymphal infection prevalence, or NIPAll) and HIS prevalence among the infected ticks (NIPHIS). In 2006, we found positive associations of the relative abundances of mice, of chipmunks, and of shrews with NIPAll. We also found positive associations of NIPHIS with shrews, and with host community diversity (H’), but negative associations with mice, and with chipmunks. In 2009, the relative abundance of mice showed a positive association with NIPAll, whereas the relative abundance of shrews and of H’ showed a negative association. With NIPHIS, only H’ showed a positive association, whereas the relative abundances of mice, of chipmunks, and of shrews, had negative associations. Our study highlights the variability between two years in the effects of host composition on B. burgdorferi genotypes. More importantly, our results highlight how disease risk inference, based on the role of host community, changes when we examine risk overall or at the phenotypic level. Long-term studies will be necessary to detect any consistent effects of host community composition on genotypic variation in the Lyme disease spirochetes
Supplemental material2 - Supplemental material for Building and Maintaining a Citizen Science Network With Fishermen and Fishing Communities Post Deepwater Horizon Oil Disaster Using a CBPR Approach
No full textSupplemental material, Supplemental material2 for Building and Maintaining a Citizen Science Network With Fishermen and Fishing Communities Post Deepwater Horizon Oil Disaster Using a CBPR Approach by Academic Authors: John Sullivan, Sharon Croisant, Marilyn Howarth, Gilbert T. Rowe, Harshica Fernando, Amanda Phillips-Savoy, Dan Jackson, John Prochaska, Ghulam A. S. Ansari, Trevor M. Penning, Cornelis Elferink and Community Partner Authors: Louisiana Environmental Action Network, United Houma Nation, Bayou Interfaith Shared Community Organizing, Dustin Nguyen-Vietnamese Community Partner, Center for Environmental & Economic Justice, and Alabama Fisheries CooperativeProject Community Scientist Author: Wlima Subra in NEW SOLUTIONS: A Journal of Environmental and Occupational Health Policy</p
Supplemental material1 - Supplemental material for Building and Maintaining a Citizen Science Network With Fishermen and Fishing Communities Post Deepwater Horizon Oil Disaster Using a CBPR Approach
No full textSupplemental material, Supplemental material1 for Building and Maintaining a Citizen Science Network With Fishermen and Fishing Communities Post Deepwater Horizon Oil Disaster Using a CBPR Approach by Academic Authors: John Sullivan, Sharon Croisant, Marilyn Howarth, Gilbert T. Rowe, Harshica Fernando, Amanda Phillips-Savoy, Dan Jackson, John Prochaska, Ghulam A. S. Ansari, Trevor M. Penning, Cornelis Elferink and Community Partner Authors: Louisiana Environmental Action Network, United Houma Nation, Bayou Interfaith Shared Community Organizing, Dustin Nguyen-Vietnamese Community Partner, Center for Environmental & Economic Justice, and Alabama Fisheries CooperativeProject Community Scientist Author: Wlima Subra in NEW SOLUTIONS: A Journal of Environmental and Occupational Health Policy</p
Supplemental material4 - Supplemental material for Building and Maintaining a Citizen Science Network With Fishermen and Fishing Communities Post Deepwater Horizon Oil Disaster Using a CBPR Approach
No full textSupplemental material, Supplemental material4 for Building and Maintaining a Citizen Science Network With Fishermen and Fishing Communities Post Deepwater Horizon Oil Disaster Using a CBPR Approach by Academic Authors: John Sullivan, Sharon Croisant, Marilyn Howarth, Gilbert T. Rowe, Harshica Fernando, Amanda Phillips-Savoy, Dan Jackson, John Prochaska, Ghulam A. S. Ansari, Trevor M. Penning, Cornelis Elferink and Community Partner Authors: Louisiana Environmental Action Network, United Houma Nation, Bayou Interfaith Shared Community Organizing, Dustin Nguyen-Vietnamese Community Partner, Center for Environmental & Economic Justice, and Alabama Fisheries CooperativeProject Community Scientist Author: Wlima Subra in NEW SOLUTIONS: A Journal of Environmental and Occupational Health Policy</p
Supplemental material3 - Supplemental material for Building and Maintaining a Citizen Science Network With Fishermen and Fishing Communities Post Deepwater Horizon Oil Disaster Using a CBPR Approach
No full textSupplemental material, Supplemental material3 for Building and Maintaining a Citizen Science Network With Fishermen and Fishing Communities Post Deepwater Horizon Oil Disaster Using a CBPR Approach by Academic Authors: John Sullivan, Sharon Croisant, Marilyn Howarth, Gilbert T. Rowe, Harshica Fernando, Amanda Phillips-Savoy, Dan Jackson, John Prochaska, Ghulam A. S. Ansari, Trevor M. Penning, Cornelis Elferink and Community Partner Authors: Louisiana Environmental Action Network, United Houma Nation, Bayou Interfaith Shared Community Organizing, Dustin Nguyen-Vietnamese Community Partner, Center for Environmental & Economic Justice, and Alabama Fisheries CooperativeProject Community Scientist Author: Wlima Subra in NEW SOLUTIONS: A Journal of Environmental and Occupational Health Policy</p
Contribution of individual and cumulative frailty-related health deficits on cardiac rehabilitation completion
No full textAbstract Background Despite the high burden of frailty among cardiac rehabilitation (CR) participants, it is unclear which frailty-related deficits are related to program completion. Methods Data from a single-centre exercise- and education-based CR program were included. A frailty index (FI) based on 25 health deficits was constructed. Logistic regression was used to estimate the odds of CR completion based on the presence of individual FI items. The odds of completion for cumulative deficits related to biomarkers, body composition, quality of life, as well as a composite of traditional and non-traditional cardiovascular risk factor domains were examined. Results A total of 3,756 individuals were included in analyses. Eight of 25 FI variables were positively associated with program completion while 8 others were negatively associated with completion. The variable with the strongest positive association was the food frequency questionnaire score (OR 1.27 (95% CI 1.14, 1.41), whereas the deficit with strongest negative association was a decline in health over the last year (OR 0.74 (95% CI 0.58, 0.93). An increased number of cardiovascular deficits were associated with an increased odds of CR completion (OR per 1 deficit increase 1.16 (95% CI 1.11, 1.22)). A higher number of traditional CR deficits were predictive of CR completion (OR 1.22 (95% CI 1.16, 1.29)), but non-traditional measures predicted non-completion (OR 0.95 (95% CI 0.92, 0.97)). Conclusion A greater number of non-traditional cardiovascular deficits was associated with non-completion. These data should be used to implement intervention to patients who are most vulnerable to drop out to maximize retention
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