Dynamical models for sand ripples beneath surface waves

We introduce order parameter models for describing the dynamics of sand ripple patterns under oscillatory flow. A crucial ingredient of these models is the mass transport between adjacent ripples, which we obtain from detailed numerical simulations for a range of ripple sizes. Using this mass transport function, our models predict the existence of a stable band of wavenumbers limited by secondary instabilities. Small ripples coarsen in our models and this process leads to a sharply selected final wavenumber, in agreement with experimental observations.Comment: 9 pages. Shortened version of previous submissio

Pivoting Health Promotional Efforts Among Fathers

The ideas of “father” and “family” as they are traditionally defined may possibly limit the effectiveness of parenting interventions among certain groups of contemporary fathers. Strongly held normative beliefs portraying men as daft caregivers and/or characterizing most families as traditional with mother serving as primary caregiver may not be appropriately addressing the needs of many modern American families. Each father has his unique needs and sets of skills that must be taken into consideration when developing health outreach programs. Essentially, effective parenting curriculum should be tailored to specific types of fathers. Health promotion and health education professionals need to become aware of these newly emerging fathers in order to create more relevant and effective educational programs. This discussion is an attempt to bring awareness to this issue and help facilitate a transition from a singular approach to fatherhood outreach rooted in traditional characterizations of “family” and “father” to a more diverse, multifactorial approach addressing more unique populations of fathers, hereby called Generation F. A pedagogical guideline to assist in developing more effective interventions targeting fathers is presented