4,217 research outputs found
Competing epidemics on complex networks
Human diseases spread over networks of contacts between individuals and a
substantial body of recent research has focused on the dynamics of the
spreading process. Here we examine a model of two competing diseases spreading
over the same network at the same time, where infection with either disease
gives an individual subsequent immunity to both. Using a combination of
analytic and numerical methods, we derive the phase diagram of the system and
estimates of the expected final numbers of individuals infected with each
disease. The system shows an unusual dynamical transition between dominance of
one disease and dominance of the other as a function of their relative rates of
growth. Close to this transition the final outcomes show strong dependence on
stochastic fluctuations in the early stages of growth, dependence that
decreases with increasing network size, but does so sufficiently slowly as
still to be easily visible in systems with millions or billions of individuals.
In most regions of the phase diagram we find that one disease eventually
dominates while the other reaches only a vanishing fraction of the network, but
the system also displays a significant coexistence regime in which both
diseases reach epidemic proportions and infect an extensive fraction of the
network.Comment: 14 pages, 5 figure
POTENTIAL EFFECTS OF SUBSIDIZED LIVESTOCK INSURANCE ON LIVESTOCK PRODUCTION
Recent legislation has cleared the way for subsidized livestock price insurance. Such programs could increase production. Expected feeder cattle prices with and without subsidized insurance will be analyzed using E-V and Stochastic Dominance. Results will highlight the potential effects of the program on marketing risk and production decisions.Livestock Production/Industries, Risk and Uncertainty,
Bedrock Geology of Cedar County, Iowa Final Phase: Bedrock Geologic Map of Cedar County 1:100,000
https://ir.uiowa.edu/igs_ofm/1060/thumbnail.jp
Vortex Formation by Interference of Multiple Trapped Bose-Einstein Condensates
We report observations of vortex formation as a result of merging together
multiple Rb Bose-Einstein condensates (BECs) in a confining potential.
In this experiment, a trapping potential is partitioned into three sections by
a barrier, enabling the simultaneous formation of three independent,
uncorrelated condensates. The three condensates then merge together into one
BEC, either by removal of the barrier, or during the final stages of
evaporative cooling if the barrier energy is low enough; both processes can
naturally produce vortices within the trapped BEC. We interpret the vortex
formation mechanism as originating in interference between the initially
independent condensates, with indeterminate relative phases between the three
initial condensates and the condensate merging rate playing critical roles in
the probability of observing vortices in the final, single BEC.Comment: 5 pages, 3 figure
Theoretical and Practical Capacities of Transit Modes
The transporting capacities of diffÂerent transit modes are often discussed, but values quoted for different modes vary widely because of differing assumpÂtions. This paper presents the basic theory of capacity and gives explanation of and insight to three aspects which must be carefully considered in capacity analysis: Way capacity and station capacity of transit modes usually vary greatly;
Capacity must be considered together\u27 with service quality, primarily operÂating safety and speed; and
There is a considerable difference b-tween theoretical and practical ·capacities of modes: the latter are important for design.
Bedrock geology of southeast Iowa, Digital geologic map of Iowa, Phase 7: Southeast Iowa
https://ir.uiowa.edu/igs_ofm/1032/thumbnail.jp
Homophobia and Sport Experience: A Survey of College Students
Athlete (n = 246) and nonathlete (n = 135) students (381 total) from a mid-sized, rural university completed the Attitudes Towards lesbians and Gay Men Scale (ATLG; Herek, 1984). Average ratings for attitudes toward and perceptions of gay men and lesbians ranged from negative to mixed. Females scored significantly lower on homophobia than males, while athletes rated sigriificantly higher on homophobia than nonathletes. The results suggest that athletes, at least those from primarily rural areas, have less tolerance for lesbians and gay men than nonathletes. Results and implications for counselors are discussed in the context of the conservatism of athletics, sport as an arena of masculinity, heterosexism, lack of knowledge about lesbians and gay men, and other sociocultural influences
Knowledge of AIDS and Risky Sexual Behaviors among Athletes
This research investigated sexual behaviors and AIDS knowledge for 381 students, athletes (n=246) and nonathletes (n=135), at a rural university. Nonathletes and athletes scored similarly on an AIDS knowledge test, but differed in reported risky sexual behavior. Athletes reported more behavioral changes after Magic Johnson's HIV-related retirement, but they still reported having more sexual partners per year than did nonathletes. The groups did not differ in condom use. By engaging in such risky behaviors, athletes may be more susceptible to sexually transmitted diseases like AIDS. Athletes (and nonathletes) continue to engage in unsafe sexual behaviors even while in possession of adequate knowledge of the risks. These results support previous research that has found that knowledge is not a valid predictor of sexual behavior (Ehde et al., 1995; Hays & Hays, 1992, Walters, 1992). Implications for athletic counselors were discussed
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