6,229 research outputs found
Static search games played over graphs and general metric spaces
We define a general game which forms a basis for modelling situations of static search and concealment over regions with spatial structure. The game involves two players, the searching player and the concealing player, and is played over a metric space. Each player simultaneously chooses to deploy at a point in the space; the searching player receiving a payoff of 1 if his opponent lies within a predetermined radius r of his position, the concealing player receiving a payoff of 1 otherwise. The concepts of dominance and equivalence of strategies are examined in the context of this game, before focusing on the more specific case of the game played over a graph. Methods are presented to simplify the analysis of such games, both by means of the iterated elimination of dominated strategies and through consideration of automorphisms of the graph. Lower and upper bounds on the value of the game are presented and optimal mixed strategies are calculated for games played over a particular family of graphs
BEATLES HERITAGE IN LIVERPOOL AND ITS ECONOMIC AND CULTURAL SECTOR IMPACT: A REPORT FOR LIVERPOOL CITY COUNCIL
This report and the underlying research were undertaken by three research institutes based in the University of Liverpool and Liverpool John Moores University: the Institute of Popular Music at the University of Liverpool; the European Institute of Urban Affairs at Liverpool John Moores University; and the Institute of Cultural Capital, a department jointly supported by both universities, established after the 2008 European Capital of Culture. The report is based on interviews with a snowball sample of the Beatles industry in Liverpool across Core, Semiperiphery and Periphery stakeholders. Interviews were supplemented by data from literature, prior work and regional economic data
Variation in movement strategies: Capital versus income migration.
This is the final version. Available from Wiley via the DOI in this record. DATA AVAILABILITY STATEMENT:
Data used to produce Figure 3 were accessed at the online Mendeley
Data repository https://data.mendeley.com/datasets/wkv96vcvnj/1
Lameris (2018b).Animal migrations represent the regular movements of trillions of individuals. The scale of these movements has inspired human intrigue for millennia and has been intensively studied by biologists. This research has highlighted the diversity of migratory strategies seen across and within migratory taxa: while some migrants temporarily express phenotypes dedicated to travel, others show little or no phenotypic flexibility in association with migration. However, a vocabulary for describing these contrasting solutions to the performance trade-offs inherent to the highly dynamic lifestyle of migrants (and strategies intermediate between these two extremes) is currently missing. We propose a taxon-independent organising framework based on energetics, distinguishing between migrants that forage as they travel (income migrants) and those that fuel migration using energy acquired before departure (capital migrants). Not only does our capital:income continuum of migratory energetics account for the variable extent of phenotypic flexibility within and across migrant populations, but it also aligns with theoreticians' treatment of migration and clarifies how migration impacts other phases of the life cycle. As such, it provides a unifying scale and common vacabulary for comparing the migratory strategies of divergent taxa
A spatial model with pulsed releases to compare strategies for the sterile insect technique applied to the mosquito Aedes aegypti
We present a simple mathematical model to replicate the key features of the sterile insect technique (SIT) for controlling pest species, with particular reference to the mosquito Aedes aegypti, the main vector of dengue fever. The model differs from the majority of those studied previously in that it is simultaneously spatially explicit and involves pulsed, rather than continuous, sterile insect releases. The spatially uniform equilibria of the model are identified and analysed. Simulations are performed to analyse the impact of varying the number of release sites, the interval between pulsed releases and the overall volume of sterile insect releases on the effectiveness of SIT programmes.
Results show that, given a fixed volume of available sterile insects, increasing the number of release sites and the frequency of releases increases the effectiveness of SIT programmes. It is also observed that programmes may become completely ineffective if the interval between pulsed releases is greater that a certain threshold value and that, beyond a certain point, increasing the overall volume of sterile insects released does not improve the effectiveness of SIT. It is also noted that insect dispersal drives a rapid recolonisation of areas in which the species has been eradicated and we argue that understanding the density dependent mortality of released insects is necessary to develop efficient, cost-effective SIT programmes
Things change: Women’s and men’s marital disruption dynamics in Italy during a time of social transformations, 1970-2003
We study women’s and men’s marital disruption in Italy between 1970 and 2003. By applying an event-history analysis to the 2003 Italian variant of the Generations and Gender Survey we found that the spread of marital disruption started among middle-highly educated women. Then in recent years it appears that less educated women have also been able to dissolve their unhappy unions. Overall we can see the beginning of a reversed educational gradient from positive to negative. In contrast the trend in men’s marital disruption risk appears as a change over time common to all educational groups, although with persisting educational differentials.determinants, educational differences, event history analysis, gender difference, Italy, marital disruption
Recommended from our members
The association between sleep patterns and obesity in older adults.
BackgroundReduced sleep duration has been increasingly reported to predict obesity. However, timing and regularity of sleep may also be important. In this study, the cross-sectional association between objectively measured sleep patterns and obesity was assessed in two large cohorts of older individuals.MethodsWrist actigraphy was performed in 3053 men (mean age: 76.4 years) participating in the Osteoporotic Fractures in Men Study and 2985 women (mean age: 83.5 years) participating in the Study of Osteoporotic Fractures. Timing and regularity of sleep patterns were assessed across nights, as well as daytime napping.ResultsGreater night-to-night variability in sleep duration and daytime napping were associated with obesity independent of mean nocturnal sleep duration in both men and women. Each 1 h increase in the standard deviation of nocturnal sleep duration increased the odds of obesity 1.63-fold (95% confidence interval: 1.31-2.02) among men and 1.22-fold (95% confidence interval: 1.01-1.47) among women. Each 1 h increase in napping increased the odds of obesity 1.23-fold (95% confidence interval: 1.12-1.37) in men and 1.29-fold (95% confidence interval: 1.17-1.41) in women. In contrast, associations between later sleep timing and night-to-night variability in sleep timing with obesity were less consistent.ConclusionsIn both older men and women, variability in nightly sleep duration and daytime napping were associated with obesity, independent of mean sleep duration. These findings suggest that characteristics of sleep beyond mean sleep duration may have a role in weight homeostasis, highlighting the complex relationship between sleep and metabolism
Brain glucose sensing, glucokinase and neural control of metabolism and islet function.
It is increasingly apparent that the brain plays a central role in metabolic homeostasis, including the maintenance of blood glucose. This is achieved by various efferent pathways from the brain to periphery, which help control hepatic glucose flux and perhaps insulin-stimulated insulin secretion. Also, critically important for the brain given its dependence on a constant supply of glucose as a fuel--emergency counter-regulatory responses are triggered by the brain if blood glucose starts to fall. To exert these control functions, the brain needs to detect rapidly and accurately changes in blood glucose. In this review, we summarize some of the mechanisms postulated to play a role in this and examine the potential role of the low-affinity hexokinase, glucokinase, in the brain as a key part of some of this sensing. We also discuss how these processes may become altered in diabetes and related metabolic diseases.Funding and support from Wellcome Trust, Medical Research Council including the
Cambridge MRC Centre for Study of Obesity and Related Disorders (MRC-CORD), NIHR
Cambridge Biomedical Research Centre, Diabetes UK (RD05/003059) and Yousef Jameel
Fund).This is the final version published version. It first appeared at http://onlinelibrary.wiley.com/doi/10.1111/dom.12334/abstract
BEATLES HERITAGE IN LIVERPOOL AND ITS ECONOMIC AND CULTURAL SECTOR IMPACT: A REPORT FOR LIVERPOOL CITY COUNCIL
This report and the underlying research were undertaken by three research institutes based in the University of Liverpool and Liverpool John Moores University: the Institute of Popular Music at the University of Liverpool; the European Institute of Urban Affairs at Liverpool John Moores University; and the Institute of Cultural Capital, a department jointly supported by both universities, established after the 2008 European Capital of Culture. The report is based on interviews with a snowball sample of the Beatles industry in Liverpool across Core, Semiperiphery and Periphery stakeholders. Interviews were supplemented by data from literature, prior work and regional economic data
- …