Non-Gaussian fluctuations in stochastic models with absorbing barriers

The dynamics of a one-dimensional stochastic model is studied in presence of an absorbing boundary. The distribution of fluctuations is analytically characterized within the generalized van Kampen expansion, accounting for higher order corrections beyond the conventional Gaussian approximation. The theory is shown to successfully capture the non Gaussian traits of the sought distribution returning an excellent agreement with the simulations, for {\it all times} and arbitrarily {\it close} to the absorbing barrier. At large times, a compact analytical solution for the distribution of fluctuations is also obtained, bridging the gap with previous investigations, within the van Kampen picture and without resorting to alternative strategies, as elsewhere hypothesized.Comment: 2 figures, submitted to Phys. Rev. Let

Can a microscopic stochastic model explain the emergence of pain cycles in patients?

A stochastic model is here introduced to investigate the molecular mechanisms which trigger the perception of pain. The action of analgesic drug compounds is discussed in a dynamical context, where the competition with inactive species is explicitly accounted for. Finite size effects inevitably perturb the mean-field dynamics: Oscillations in the amount of bound receptors spontaneously manifest, driven by the noise which is intrinsic to the system under scrutiny. These effects are investigated both numerically, via stochastic simulations and analytically, through a large-size expansion. The claim that our findings could provide a consistent interpretative framework to explain the emergence of cyclic behaviors in response to analgesic treatments, is substantiated.Comment: J. Stat. Mech. (Proceedings UPON2008

Partnerships in Service Learning and Civic Engagement

Developing campus-community partnerships is a core element of well-designed and effective civic engagement, including service learning and participatory action research. A structural model, SOFAR, is presented that differentiates campus into administrators, faculty, and students, and that differentiates community into organizational staff and residents (or clients, consumers, advocates). Partnerships are presented as being a subset of relationships between persons. The quality of these dyadic relationships is analyzed in terms of the degree to which the interactions possess closeness, equity, and integrity, and the degree to which the outcomes of those interactions are exploitive, transactional, or transformational. Implications are then offered for how this analysis can improve practice and research

Status of Simulation-Based Training in Departments of Surgery in the United States

Background: Surgical simulation is particularly attractive because it allows training in a safe, controlled, and standardized environment. However, the status of surgical simulation among Departments of Surgery (DoS) in the United States is unknown. The objective of this study was to characterize the status of simulation-based training in DoS in the United States. Materials and methods: A Qualtrics online survey was sent to 177 chairs of DoS in the United States in March 2018 regarding the utilization of surgical simulation in their department. Questions in the survey were focused on simulation capacities and activities as well as chairs' perception of the value and purpose of simulation. Results: A total of 87 of 177 chairs responded to the survey (49% response rate). Most programs had either 20-50 trainees (42 of 87; 48%) or more than 50 trainees (37 of 87; 43%). Most chairs reported having a simulation center in their institution (85 of 87; 98%) or department (60 of 86; 70%) with a formal simulation curriculum for their trainees (83 of 87; 95%). Ninety percent (78 of 87) of DoS had protected time for simulation education for their residents, with most residents engaging in activities weekly or monthly (65 of 85; 76%). Although most chairs felt simulation improves patient safety (72 of 84; 86%) and is useful for practicing surgeons (68 of 84; 81%), only 40% reported that faculty use simulation to maintain technical skills and only 17% reported that faculty use simulation to address high complication rates. Conclusions: The vast majority of the DoS in the United States have established simulation activities for their trainees. However, engagement of faculty in simulation to maintain or improve their skills remains low