Dynamics of a deformable self-propelled domain

We investigate the dynamical coupling between the motion and the deformation of a single self-propelled domain based on two different model systems in two dimensions. One is represented by the set of ordinary differential equations for the center of gravity and two tensor variables characterizing deformations. The other is an active cell model which has an internal mechanism of motility and is represented by the partial differential equation for deformations. Numerical simulations show a rich variety of dynamics, some of which are common to the two model systems. The origin of the similarity and the difference is discussed.Comment: 6 pages, 6 figure

Social Norms and Fundraising: The Trade-Off Between Enhanced Donations and Donor Identity Esteem

peerreview_statement: The publishing and review policy for this title is described in its Aims & Scope. aims_and_scope_url: http://www.tandfonline.com/action/journalInformation?show=aimsScope&journalCode=wnon2

A frequentist framework of inductive reasoning

Reacting against the limitation of statistics to decision procedures, R. A. Fisher proposed for inductive reasoning the use of the fiducial distribution, a parameter-space distribution of epistemological probability transferred directly from limiting relative frequencies rather than computed according to the Bayes update rule. The proposal is developed as follows using the confidence measure of a scalar parameter of interest. (With the restriction to one-dimensional parameter space, a confidence measure is essentially a fiducial probability distribution free of complications involving ancillary statistics.) A betting game establishes a sense in which confidence measures are the only reliable inferential probability distributions. The equality between the probabilities encoded in a confidence measure and the coverage rates of the corresponding confidence intervals ensures that the measure's rule for assigning confidence levels to hypotheses is uniquely minimax in the game. Although a confidence measure can be computed without any prior distribution, previous knowledge can be incorporated into confidence-based reasoning. To adjust a p-value or confidence interval for prior information, the confidence measure from the observed data can be combined with one or more independent confidence measures representing previous agent opinion. (The former confidence measure may correspond to a posterior distribution with frequentist matching of coverage probabilities.) The representation of subjective knowledge in terms of confidence measures rather than prior probability distributions preserves approximate frequentist validity.Comment: major revisio

Time and Financial Transfers Within and Beyond the Family

Research on time and financial transfers is often conducted along two distinct lines—transfers within the family and transfers beyond the family—without considering the fact that these transfers are actually interrelated. Using longitudinal data from the Health and Retirement Study (HRS), this article investigates the links between the two groups of transfers. Transfers within and beyond the family were found to be complements. Income and wealth are strong predictors of financial transfers. Black and Hispanic families lag systematically in the generosity to help the people both within and beyond their families.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43105/1/10834_2006_Article_9013.pd

The ethics of entrepreneurial philanthropy

A salient if under researched feature of the new age of global inequalities is the rise to prominence of entrepreneurial philanthropy, the pursuit of transformational social goals through philanthropic investment in projects animated by entrepreneurial principles. Super-wealthy entrepreneurs in this way extend their suzerainty from the domain of the economic to the domains of the social and political. We explore the ethics and ethical implications of entrepreneurialphilanthropy through systematic comparison with what we call customaryphilanthropy, which preferences support for established institutions and social practices. We analyse the ethical statements made at interview by 24 elite UK philanthropists, 12 customary and 12 entrepreneurial, to reveal the co-existence of two ethically charged narratives of elite philanthropic motivations, each instrumental in maintaining the established socio-economic order. We conclude that entrepreneurial philanthropy, as an ostensibly efficacious instrument of social justice, is ethically flawed by its unremitting impulse toward ideological purity

Business elites and the field of power in France

Bourdieu’s construct of the field of power has received relatively little attention despite its novelty and theoretical potential. This paper explores the meaning and implications of the construct, and integrates it into a wider conception of the formation and functioning of elites at the highest level in society. Drawing on an extensive dataset profiling the careers of members of the French business elite, it compares and contrasts those who enter the field of power with those who fail to qualify for membership, exploring why some succeed as hyper-agents while others do not. The alliance of social origin and educational attainment, class and meritocracy, emerges as particularly compelling. The field of power is shown to be relatively variegated and fluid, connecting agents from different life worlds. Methodologically, this paper connects biographical data of top French directors with the field of power in France in a novel way, while presenting an operationalization of Bourdieu’s concept of the field of power as applied to the French elite

Bayesian calibration, validation and uncertainty quantification for predictive modelling of tumour growth: a tutorial

In this work we present a pedagogical tumour growth example, in which we apply calibration and validation techniques to an uncertain, Gompertzian model of tumour spheroid growth. The key contribution of this article is the discussion and application of these methods (that are not commonly employed in the field of cancer modelling) in the context of a simple model, whose deterministic analogue is widely known within the community. In the course of the example we calibrate the model against experimental data that is subject to measurement errors, and then validate the resulting uncertain model predictions. We then analyse the sensitivity of the model predictions to the underlying measurement model. Finally, we propose an elementary learning approach for tuning a threshold parameter in the validation procedure in order to maximize predictive accuracy of our validated model