Decisions and disease: a mechanism for the evolution of cooperation

In numerous contexts, individuals may decide whether they take actions to mitigate the spread of disease, or not. Mitigating the spread of disease requires an individual to change their routine behaviours to benefit others, resulting in a 'disease dilemma' similar to the seminal prisoner's dilemma. In the classical prisoner's dilemma, evolutionary game dynamics predict that all individuals evolve to 'defect.' We have discovered that when the rate of cooperation within a population is directly linked to the rate of spread of the disease, cooperation evolves under certain conditions. For diseases which do not confer immunity to recovered individuals, if the time scale at which individuals receive information is sufficiently rapid compared to the time scale at which the disease spreads, then cooperation emerges. Moreover, in the limit as mitigation measures become increasingly effective, the disease can be controlled, and the rate of infections tends to zero. Our model is based on theoretical mathematics and therefore unconstrained to any single context. For example, the disease spreading model considered here could also be used to describe social and group dynamics. In this sense, we may have discovered a fundamental and novel mechanism for the evolution of cooperation in a broad sense

Floating Widgets: Interaction with Acoustically-Levitated Widgets

Acoustic levitation enables new types of human-computer interface, where the content that users interact with is made up from small objects held in mid-air. We show that acoustically-levitated objects can form mid-air widgets that respond to interaction. Users can interact with them using in-air hand gestures. Sound and widget movement are used as feedback about the interaction

Does the regulation of manure land application work against agglomeration economies? Theory and evidence from the French hog sector

The well-known increase in the geographical concentration of hog production suggests the presence of agglomeration economies related to spatial spillovers and inter-dependencies among industries. In this paper, we examine whether the restrictions on land application of manure may weaken productivity gains arising from the agglomeration process. We develop a model of production showing the ambiguous spatial effect of land availability and the restriction on the manure application rate. Indeed, while the regulation of manure application triggers dispersion when manure is applied to land as a crop nutrient, it also prompts farmer to adopt manure treatment that favors agglomeration of hog production. Estimations of a reduced form of the spatial model with a spatial HAC procedure applied to data for French hog production for 1988 and 2000 confirm the ambiguous effect of land limitations induced by the restrictions on manure application. It does not prevent spatial concentration of hog production, and even boosts the role played by spatial spillovers in the agglomeration process.hog production, land availability, manure application regulation, agglomeration economies, spatial econometrics

Movers and Shakers in the Library Publishing World Highlight their Roles: Interviews with Print and Electronic Journal Editors - A Comparison

Abstract This paper reports the interviews of five Emerald Group and three electronic journal editors. Several topics were discussed, including the definition of a peer reviewed journal article, the role of the editor, the work involved in editing, the role of the editorial board, ways to get on the editorial board, the acceptance rate of the journal, and topics of interest for future publication. The experience provided insight into the working mechanisms of journal publishing and clearly showed that there are many similarities among the editors’ roles, relationships, workloads, and understanding of the peer review concept, no matter which format is considered

Estuarine Suspended Sediment Loads and Sediment Budgets in Tributaries of Chesapeake Bay Phase 1: York, Patuxent, and Potomac Rivers

Understanding the sources and sinks of suspended sediment in Chesapeake Bay tributaries is an important contribution to quantifying the Bay sediment budget, as well as an aid to management strategies. The purpose of the project was to identify estuarine sediment transport processes and estimate sediment loads and sediment budgets for the major tributaries of the Bay. The first phase included the York River, Va. and the Patuxent River, Md. Sediment transport processes, sediment loads, and a partial budget also were developed for the Potomac River, Md. The results of this study represent the most comprehensive calculations to date of sediment loads for Bay tributaries. The three rivers exhibit different magnitudes and transport directions of sediment loads at individual stations. Average sediment loads for the rivers as a whole show the York, Patuxent, and Potomac all importing sediment. Sediment budgets for the York and Patuxent show a sediment loss that is unaccounted for; i.e. more sediment is needed from sources, or sinks are too large. The York River is highly energetic, moving large amounts of sediment within the estuary. The Patuxent River is less energetic but more variable in redistributing sediment. Important future work for a more comprehensive understanding of suspended sediment transport in the Chesapeake Bay includes completion of the sediment budget for the Potomac River and calculation of estuarine transport processes, sediment loads, and sediment budgets for the James and Rappahannock Rivers, Va

Categorization of shellfish TMDL sites Final Report

There were two important goals for this project, including the assembly and compilation of digital data for the Coastal Plain and tidal waters of Virginia, and the categorization of the Division of Shellfish Sanitation (DSS) shellfish growing areas to determine if some are similar enough for water quality models to be effectively transferred from the modeled growing areas to other areas. This report summarizes the data and statistical analyses and discusses the results. Note: The digital data has a very fine resolution. The maps displayed in this report cannot convey this information on 8.5x11 paper. All digital data layers (shape files and grids), digital maps (jpgs), data files (excel files) and a digital copy of this report (pdf format) are included on 3 cdroms that accompany this report. The cdroms include a text file (called Readme.txt) that provides an explanation of each of the data layers and pertinent information in the tables contained in the data layers

Evolution of Tidal Marsh Distribution under Accelerating Sea Level Rise

Tidal marshes are important ecological systems that are responding to sea level rise-driven changes in tidal regimes. Human development along the coastline creates barriers to marsh migration, moderating tidal marsh distributions. This study shows that in the Chesapeake Bay, USA an estuarine system with geographic and development variability, overall estuarine tidal marshes are projected to decline by approximately half over the next century. Tidal freshwater and oligohaline habitats, which are found in the upper reaches of the estuary and are typically backed by high elevation shorelines are particularly vulnerable. Due to their geological setting, losses of large extents of tidal freshwater habitat seem inevitable under sea level rise. However, in the meso/poly/euhaline zones that (in passive margin estuaries) are typically low relief areas, tidal marshes are capable of undergoing expansion. These areas should be prime management targets to maximize future tidal marsh extent. Redirecting new development to areas above 3 m in elevation and actively removing impervious surfaces as they become tidally inundated results in the maximum sustainability of natural coastal habitats. Under increasing sea levels and flooding, the future of tidal marshes will rely heavily on the policy decisions made, and the balance of human and natural landscapes in the consideration of future development

L’intervention auprès de jeunes mères et de leur enfant : perspective de la théorie de l’attachement

The children of adolescent mothers are among those presenting the highest level of psychosocial risk, compromising their socio-emotional development on a number of levels. Several intervention strategies have been designed to address some of the problems that characterize these mother-infant dyads. While these strategies have proven to be beneficial to young mothers, relatively little impact has been found on the level of infant and child development. The purpose of this article is to address the issue of intervention aimed at adolescent mothers and their infant, and underline that the relational dimension, while absent from most intervention programs, is necessary to our understanding of the problems presented by these dyads. An intervention program, currently undergoing evaluation, is described having as a main objective the improvement of the early mother-infant relationship. Attachment theory is presented as an organizing construct. Characteristics of the intervention, as well as the evaluation strategy, are described

Prioritizing the protection and creation of natural and naturebased features for coastal resilience using a GIS-based ranking framework – an exportable approach

Increasing the preservation and creation of natural and nature-based features (NNBF), like wetlands, living shorelines, beaches, dunes and other natural features to improve community resilience in the face of increasing coastal flooding may be achieved by highlighting the locally relevant benefits that these features can provide. Here we present a novel application of the least-cost geospatial modeling approach to generate inundation pathways that highlight landscape connections between NNBF and vulnerable infrastructure. Inundation pathways are then used to inform a ranking framework that assesses NNBF based on their provision of benefits and services to vulnerable infrastructure and for the broader community including 1) the flooding mitigation potential of NNBF, 2) the relative impact of those NNBF on local infrastructure, and 3) co-benefits for the broader community linked to incentive programs like nutrient reduction crediting and the Federal Emergency Management Agency’s Community Rating System. Inundation pathways are also used to identify locations lacking in benefits from NNBF as target areas for NNBF restoration or creation. This approach, applied here for coastal Virginia, with project outputs available via an interactive map viewer1, can be customized for application in any community to identify high-priority NNBF that are particularly beneficial for preservation and to identify target areas for new or restored features