The influence of environmental spatial structure on the life history traits and diversity of species in a metacommunity

Several models have been proposed to understand how so many species can coexist in ecosystems. Despite evidence showing that natural habitats are often patchy and fragmented, these models rarely take into account environmental spatial structure. In this study we investigated the influence of spatial structure in habitat and disturbance regime upon species' traits and species' coexistence in a metacommunity. We used a population-based model to simulate competing species in spatially explicit landscapes. The species traits we focused on were dispersal ability, competitiveness, reproductive investment and survival rate. Communities were characterized by their species richness and by the four life-history traits averaged over all the surviving species. Our results show that spatial structure and disturbance have a strong influence on the equilibrium life-history traits within a metacommunity. In the absence of disturbance, spatially structured landscapes favour species investing more in reproduction, but less in dispersal and survival. However, this influence is strongly dependent on the disturbance rate, pointing to an important interaction between spatial structure and disturbance. This interaction also plays a role in species coexistence. While spatial structure tends to reduce diversity in the absence of disturbance, the tendency is reversed when disturbance occurs. In conclusion, the spatial structure of communities is an important determinant of their diversity and characteristic traits. These traits are likely to influence important ecological properties such as resistance to invasion or response to climate change, which in turn will determine the fate of ecosystems facing the current global ecological crisis.

Merkel cells and the individuality of friction ridge skin

There is no definite theory yet for the mechanism by which the pattern of epidermal ridges on fingers, palms and soles forming friction ridge skin (FRS) patterns is created. For a long time growth forces in the embryonal epidermis have been believed to be involved in FRS formation. More recent evidence suggests that Merkel cells play an important part in this process as well. Here we suggest a model for the formation of FRS patterns that links Merkel cells to the epidermal stress distribution. The Merkel cells are modeled as agents in an agent based model that move anisotropically where the anisotropy is created by the epidermal stress tensor. As a result ridge patterns are created with pattern defects as they occur in real FRS patterns. As a consequence we suggest why the topology of FRS patterns is indeed unique as the arrangement of pattern defects is sensitive to the initial configuration of Merkel cells.

Nouveau programme de formation en médecine interne générale: implications pour les médecins de premier recours [The new postgraduate training program in general internal medicine: implications for the primary care physician].

The Swiss postgraduate training program in general internal medicine is now designed as a competency-based curriculum. In other words, by the end of their training, the residents should demonstrate a set of predefined competences. Many of those competences have to be learnt in outpatient settings. Thus, the primary care physicians have more than ever an important role to play in educating tomorrows doctors. A competency-based model of training requires a regular assessment of the residents. The mini-CEX (mini-Clinical Evaluation eXercise) is the assessment tool proposed by the Swiss institute for postgraduate and continuing education. The mini-CEX is based on the direct observation of the trainees performing a specific task, as well as on the ensuing feedback. This article aims at introducing our colleagues in charge of residents to the mini-CEX, which is a useful tool promoting the culture of feedback in medical education.

Endeavors Update, Iowa Medicaid Enterprise, April 2013

The Iowa Medicaid Enterprise (IME) is an endeavor, started in 2005, to unite State staff with “best of breed” contractors into a performance-based model for administration of the Medicaid program.

Endeavors Update, Iowa Medicaid Enterprise, December 2012

The Iowa Medicaid Enterprise (IME) is an endeavor, started in 2005, to unite State staff with “best of breed” contractors into a performance-based model for administration of the Medicaid program.

Endeavors Update, Iowa Medicaid Enterprise, December 2013

The Iowa Medicaid Enterprise (IME) is an endeavor, started in 2005, to unite State staff with “best of breed” contractors into a performance-based model for administration of the Medicaid program.

Endeavors Update, Iowa Medicaid Enterprise, February 2013

The Iowa Medicaid Enterprise (IME) is an endeavor, started in 2005, to unite State staff with “best of breed” contractors into a performance-based model for administration of the Medicaid program.

Endeavors Update, Iowa Medicaid Enterprise, February 2014

The Iowa Medicaid Enterprise (IME) is an endeavor, started in 2005, to unite State staff with “best of breed” contractors into a performance-based model for administration of the Medicaid program.

Endeavors Update, Iowa Medicaid Enterprise, January 2013

The Iowa Medicaid Enterprise (IME) is an endeavor, started in 2005, to unite State staff with “best of breed” contractors into a performance-based model for administration of the Medicaid program.

Endeavors Update, Iowa Medicaid Enterprise, January 2014

The Iowa Medicaid Enterprise (IME) is an endeavor, started in 2005, to unite State staff with “best of breed” contractors into a performance-based model for administration of the Medicaid program.

Endeavors Update, Iowa Medicaid Enterprise, July 2013

The Iowa Medicaid Enterprise (IME) is an endeavor, started in 2005, to unite State staff with “best of breed” contractors into a performance-based model for administration of the Medicaid program.

Endeavors Update, Iowa Medicaid Enterprise, June 2013

The Iowa Medicaid Enterprise (IME) is an endeavor, started in 2005, to unite State staff with “best of breed” contractors into a performance-based model for administration of the Medicaid program.

Endeavors Update, Iowa Medicaid Enterprise, March 2014

The Iowa Medicaid Enterprise (IME) is an endeavor, started in 2005, to unite State staff with “best of breed” contractors into a performance-based model for administration of the Medicaid program.

Endeavors Update, Iowa Medicaid Enterprise, May 2013

The Iowa Medicaid Enterprise (IME) is an endeavor, started in 2005, to unite State staff with “best of breed” contractors into a performance-based model for administration of the Medicaid program.

Endeavors Update, Iowa Medicaid Enterprise, November 2012

The Iowa Medicaid Enterprise (IME) is an endeavor, started in 2005, to unite State staff with “best of breed” contractors into a performance-based model for administration of the Medicaid program.