Micromechanics of Single Supercoiled DNA Molecules

Abstract. The theory of the mechanical response of single DNA molecules un-der stretching and twisting stresses is reviewed. Using established results for the the semiflexible polymer including the effect of torsional stress, and for the free energy of plectonemic supercoils, a theory of coexisting plectonemic and extended DNA is con-structed and shown to produce phenomena observed experimentally. Analytical results for DNA extension and torque are presented, and effects of anharmonicities in the plec-tonemic free energy are described. An application of the theory to the problem of torsional-stress-induced cruciform extrusion is also discussed. Key words. DNA, molecular biology, statistical mechanics, polymer physics. AMS(MOS) subject classifications. 82D60, 92C05, 92C40

The Influence of Dormitory Architecture On Resident Behavior

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66943/2/10.1177_001391657300500402.pd

Program planners' perspectives of promotora

OBJECTIVE: Program planners work with promotoras (the Spanish term for female community health workers) to reduce health disparities among underserved populations. Based on the Role-Outcomes Linkage Evaluation Model for Community Health Workers (ROLES) conceptual model, we explored how program planners conceptualized the promotora role and the approaches and strategies they used to recruit, select, and sustain promotoras. DESIGN: We conducted semi-structured, in-depth interviews with a purposive convenience sample of 24 program planners, program coordinators, promotora recruiters, research principal investigators, and other individuals who worked closely with promotoras on United States-based health programs for Hispanic women (ages 18 and older). RESULTS: Planners conceptualized the promotora role based on their personal experiences and their understanding of the underlying philosophical tenets of the promotora approach. Recruitment and selection methods reflected planners’ conceptualizations and experiences of promotoras as paid staff or volunteers. Participants described a variety of program planning and implementation methods. They focused on sustainability of the programs, the intended health behavior changes or activities, and the individual promotoras. CONCLUSION: To strengthen health programs employing the promotora delivery model, job descriptions should delineate role expectations and boundaries and better guide promotora evaluations. We suggest including additional components such as information on funding sources, program type and delivery, and sustainability outcomes to enhance the ROLES conceptual model. The expanded model can be used to guide program planners in the planning, implementing, and evaluating of promotora health programs

An application of philosophy in software modelling and future information systems development

The influence of mainstream philosophy on conceptual modelling and on modelling language development has historically been arcane or, at best, not recognized, whilst modellers might in fact implicitly espouse one particular philosophical tenet. This paper describes and discusses philosophical stances applied to conceptual modeling in order to make such influences explicit so that we, as conceptual modellers, can take the next step. © 2013 Springer-Verlag