Lake restoration in terms of ecological resilience: a numerical study of biomanipulations under bistable conditions

An abstract version of the comprehensive aquatic simulation model (CASM) is found to exhibit bistability under intermediate loading of nutrient input, supporting the alternative-stable-states theory and field observations for shallow lakes. Our simulations of biomanipulations under the bistable conditions reveal that a reduction in the abundance of zooplanktivorous fish cannot switch the system from a turbid to a clear state. Rather, a direct reduction of phytoplankton and detritus was found to be most effective to make this switch in the present model. These results imply that multiple manipulations may be effective for practical restorations of lakes. We discuss the present results of biomanipulations in terms of ecological resilience in multivariable systems or natural systems.

Simplification of structured population dynamics in complex ecological communities

Goldstone's idea of slow dynamics resulting from spontaneously broken symmetries is applied to Hubbell's neutral hypothesis of community dynamics, to efficiently simplify stage-structured multi-species models-introducing the quasi-neutral approximation (QNA). Rather than assuming population-dynamical neutrality in the QNA, deviations from ideal neutrality, thought to be small, drive dynamics. The QNA is systematically derived to first and second order in a two-scale singular perturbation expansion. The total reproductive value of species, as computed from the effective life-history parameters resulting from the non-linear interactions with the surrounding community, emerges as the new dynamic variables in this aggregated description. Using a simple stage-structured community-assembly model, the QNA is demonstrated to accurately reproduce population dynamics in large, complex communities. Further, the utility of the QNA in building intuition for management problems is illustrated by estimating the responses of a fish stock to harvesting and variations in fecundity.

Protracted rainfall decreases temperature within leatherback turtle (Dermochelys coriacea) clutches in Grenada, West Indies: Ecological implications for a species displaying temperature dependent sex determination

Protracted or intense rainfall may affect the reproductive success of reptilian species on a number of levels ranging from the availability of prey, the integrity of the nesting site and the subsequent survivability of offspring. For sea turtles (a species displaying temperature sex determination) nesting throughout the tropics and subtropics, rainfall has previously been shown to influence the development environment of clutches; in its extreme resulting in high levels of egg or hatchling mortality. Yet when compared to other abiotic variables affecting clutch success, rainfall has received relatively little attention. We therefore examined how fluctuations in local rainfall at a tropical nesting site for leatherback turtles (Dermochelys coriacea) affected the nest environment. Temperature data loggers placed within clutches (n = 8) revealed that protracted rainfall had a marked cooling effect on nests, so that seasonally improbable male-producing temperatures (

Judicial Rehabilitation and the ‘Clean Bill of Health’ in Criminal Justice.

Drawing on an important survey of European and Australian policies toward ‘judicial rehabilitation,’ this article makes the following arguments. First, the rehabilitation movement should return to the origins of the word ‘rehabilitation’ and focus at least as much on efforts to remove and relieve ex-prisoner stigma as on treatment and reform efforts. There will be no ‘rehabilitation revolution’ without this. Second, these efforts should involve active, not passive redemption. Rehabilitation processes that require almost a decade or more of ‘crime-free’ behaviour before forgiving an individual for his or her crimes are just and fair, but they miss the point of rehabilitation. Policies should encourage, support and facilitate good behaviour and not just reward it in retrospect. Third, rehabilitation should not just be done, but be ‘seen to be done,’ ideally in a ritualised format. This sends an important message to the individual and wider society. Finally, I argue that it may be better to forgive than forget past crimes. That is, rather than burying past crimes as if they never happened, states should instead acknowledge and formally recognise that people can change, that good people can do bad things, and that all individuals should be able to move on from past convictions.

Correctable visual impairment in stroke rehabilitation patients

Background: after stroke, visual impairment may exacerbate the impact of other impairments on overall disability and negatively influence rehabilitation.