Asymptotic dynamics of attractive-repulsive swarms

We classify and predict the asymptotic dynamics of a class of swarming models. The model consists of a conservation equation in one dimension describing the movement of a population density field. The velocity is found by convolving the density with a kernel describing attractive-repulsive social interactions. The kernel's first moment and its limiting behavior at the origin determine whether the population asymptotically spreads, contracts, or reaches steady-state. For the spreading case, the dynamics approach those of the porous medium equation. The widening, compactly-supported population has edges that behave like traveling waves whose speed, density and slope we calculate. For the contracting case, the dynamics of the cumulative density approach those of Burgers' equation. We derive an analytical upper bound for the finite blow-up time after which the solution forms one or more $\delta$-functions.Comment: 23 pages, 10 figures; revised version updates the analysis in sec. 2.1 and 2.2, and contains enhanced discussion of the admissible class of social interaction force

MISSION Community Re-Entry for Women (MISSION-CREW) Program Development and Implementation [English and Spanish versions]

A Spanish translation of this publication is available to download under Additional Files below. Describes a study that examined the impact of the MISSION-CREW (Maintaining Independence and Sobriety through Systems Integration, Outreach, and Networking Community Re-Entry for Women) model of care on criminal justice outcomes for women released from MCI-Framingham and South Middlesex Correctional Center (SMCC) in Massachusetts. Originally published as: Research in the Works, Issue 5, 2011

Improving biocontrol using antagonist mixtures with heat and/or sodium bicarbonate to control postharvest decay of apple fruit

Abstract 'Golden Delicious' apples were wound-inoculated with either Colletotrichum acutatum or Penicillium expansum and then treated with various combinations of heat (38 • C) for 4 days, 2% sodium bicarbonate, and two biocontrol agents alone or combined. The fruit were stored for 4 months at 1 • C and then at 20 • C for 2 weeks. Either heat or the antagonists reduced decay caused by C. acutatum, but a combination of the two was required to completely eliminate decay caused by this pathogen in most cases. Sodium bicarbonate alone or in combination with the antagonists had little effect on C. acutatum. The antagonists alone reduced decay caused by P. expansum but tended to be more effective when combined. Sodium bicarbonate increased the effectiveness of decay control by each antagonist alone or in combination. All of the treatments that included heat virtually eliminated decay caused by this pathogen. The proper combination of alternative control measures can provide an effective strategy to reduce postharvest decay of apple fruit. Published by Elsevier B.V

Continuum modeling of the equilibrium and stability of animal flocks

Groups of animals often tend to arrange themselves in flocks that have characteristic spatial attributes and temporal dynamics. Using a dynamic continuum model for a flock of individuals, we find equilibria of finite spatial extent where the density goes continuously to zero at a well-defined flock edge, and we discuss conditions on the model that allow for such solutions. We also demonstrate conditions under which, as the flock size increases, the interior density in our equilibria tends to an approximately uniform value. Motivated by observations of starling flocks that are relatively thin in a direction transverse to the direction of flight, we investigate the stability of infinite, planar-sheet flock equilibria. We find that long- wavelength perturbations along the sheet are unstable for the class of models that we investigate. This has the conjectured consequence that sheet-like flocks of arbitrarily large transverse extent relative to their thickness do not occur. However, we also show that our model admits approximately sheet-like, 'pancake-shaped', three-dimensional ellipsoidal equilibria with definite aspect ratios (transverse length- scale to flock thickness) determined by anisotropic perceptual/response characteristics of the flocking individuals, and we argue that these pancake-like equilibria are stable to the previously mentioned sheet instability.Comment: 37 pages, 8 figure

A qualitative investigation into the impact of domestic abuse on women’s desistance

While criminological literature, criminal justice practice, and to a lesser extent, state policy have acknowledged a link between women’s criminalisation and gendered violence (MoJ, 2018; Österman, 2018; Prison Reform Trust, 2017; Roberts, 2015), there has been much less acknowledgement of the role of historical and contemporaneous experiences of violence in the desistance scripts of criminalised women. Combining findings from two research projects exploring gender and desistance, this article argues that (i) criminalised women’s experiences of gendered violence are such that any exploration of gender and desistance which does not acknowledge this is incomplete, (ii) coercion and control can inform women’s entry into the criminal justice system, (iii) expressions of agency and resistance in abusive interpersonal relationships can also inform women’s offending, yet (iv) women’s experiences of desistance from crime can mask the harm they face in coercive, controlling, and violent relationships. Thus, the article argues for a reframing of desistance from crime as desistance from harm both theoretically and in practice, and considers what this might entail

Phage Therapy and Photodynamic Therapy: Low Environmental Impact Approaches to Inactivate Microorganisms in Fish Farming Plants

Owing to the increasing importance of aquaculture to compensate for the progressive worldwide reduction of natural fish and to the fact that several fish farming plants often suffer from heavy financial losses due to the development of infections caused by microbial pathogens, including multidrug resistant bacteria, more environmentally-friendly strategies to control fish infections are urgently needed to make the aquaculture industry more sustainable. The aim of this review is to briefly present the typical fish farming diseases and their threats and discuss the present state of chemotherapy to inactivate microorganisms in fish farming plants as well as to examine the new environmentally friendly approaches to control fish infection namely phage therapy and photodynamic antimicrobial therapy