Epidemic threshold and control in a dynamic network

In this paper we present a model describing susceptible-infected-susceptible-type epidemics spreading on a dynamic contact network with random link activation and deletion where link activation can be locally constrained. We use and adapt an improved effective degree compartmental modeling framework recently proposed by Lindquist et al. [ J. Math Biol. 62 143 (2010)] and Marceau et al. [ Phys. Rev. E 82 036116 (2010)]. The resulting set of ordinary differential equations (ODEs) is solved numerically, and results are compared to those obtained using individual-based stochastic network simulation. We show that the ODEs display excellent agreement with simulation for the evolution of both the disease and the network and are able to accurately capture the epidemic threshold for a wide range of parameters. We also present an analytical R0 calculation for the dynamic network model and show that, depending on the relative time scales of the network evolution and disease transmission, two limiting cases are recovered: (i) the static network case when network evolution is slow and (ii) homogeneous random mixing when the network evolution is rapid. We also use our threshold calculation to highlight the dangers of relying on local stability analysis when predicting epidemic outbreaks on evolving networks

Orbital Variability in the Eclipsing Pulsar Binary PSR B1957+20

We have conducted timing observations of the eclipsing millisecond binary pulsar PSR~B1957+20, extending the span of data on this pulsar to more than five years. During this time the orbital period of the system has varied by roughly $\Delta P_b/P_b = 1.6 \times 10^{-7}$, changing quadratically with time and displaying an orbital period second derivative $\ddot P_b = (1.43 \pm 0.08) \times 10^{-18}\,$s$^{-1}$. The previous measurement of a large negative orbital period derivative reflected only the short-term behavior of the system during the early observations; the orbital period derivative is now positive and increasing rapidly. If, as we suspect, the PSR~B1957+20 system is undergoing quasi-cyclic orbital period variations similar to those found in other close binaries such as Algol and RS CVn, then the $0.025\,M{_\odot}$ companion to PSR~B1957+20 is most likely non-degenerate, convective, and magnetically active.Comment: 9 pages, 3 figures, LaTeX, submitted ApJL 13 Dec. 1993, arz-00

A sore red eye with systemic involvement

The study of happiness has long been a playground for philosophical speculation. By lack of empirical measures of happiness, it was not possible to check propositions about the matter. In the late 20th century, survey-research methods introduced by the social sciences have brought a break-through. Dependable measures of happiness have developed, by means of which a significant body of knowledge has evolved

A Spectacle and Nothing Strange

Working through methods of abstraction and comedic mimicry I choreograph awkwardly balanced sculpture with objects of adornment as a means to defuse personal sensitivities surrounding my experiences of gender, desire, and home. The research that follows is concerned with the adjacent, the in between, above and underneath, because I feel that this kind of looking means that you are, to some degree, aware of what lies at the edges. Maybe this is what Gertrude Stein means to act as though there is no use in a center—because this concerns a way of relating, though there are many things in the room. ‘A spectacle and nothing strange’ is an arrangement of gestures, of made difference, of kinships, of orientations and possible futures, sustained tension, coded adornment, big dyke energy, shifts in hardness, leaning softness, much more than flowers, ...and in any case there is sweetness and some of that

Attachment Styles as Moderator Between Stress and Emotional Eating in Adolescent Girls: A Research Proposal

Emotional eating is an important precursor of weight gain and obesity among adolescent girls (Halberstadt et al., 2016). Researchers have defined emotional eating as individuals’ eating behaviors in response to the positive or negative emotions they endure (Bongers & Jansen, 2016). In past studies, stress has been found to be an important indicator of emotional eating in adolescent girls (Corsica, Hood, Katterman, Kleinman, & Ivan, 2014). However, not all girls who experience stress will engage in emotional eating. The stress-diathesis model suggests that certain traits of vulnerability may predispose some individuals towards mental health problems (e.g., eating disorders) in response to stress (MacNeil, Esposito-Smythers, Mehlenbeck, & Weismore, 2012). One of the important traits that may moderate the effect of stress on mental health problems is attachment styles (Chow & Ruhl, 2014). Attachment styles are defined as the internalized mental representations of individuals’ key attachment figures (e.g., mothers; Cooper, Shaver, & Collins, 1998). Attachment styles are measured by the dimensions of anxiety (e.g., fear of being abandoned by others) and avoidance (e.g., fear of being too close to others). Combining the stress-diathesis model and attachment theory, the current study aims to investigate whether adolescent girls’ attachment security within close relationships moderates the link between experiences of stress and emotional eating. Specifically, it is hypothesized that girls who are low in attachment security engage in more emotional eating when under stress. In contrast, it is hypothesized that girls who are high in attachment security engage in less emotional eating, regardless of their stress levels. To test the hypothesis, data will be drawn from archival data including 100 adolescent girls between 11 and 18 years old. Participants answered questionnaires on stress attachment security to their parents and whether they engaged in emotional eating. Moderation hypothesis will be examined with multiple regression implemented in R