A local view of cancer

Research on solid tumors has had limited emphasis on interactions between transformed cells and their neighbors within the epithelium. Leung and Brugge (2012) use cultured breast cancer acini to demonstrate the importance of local interactions between normal and transformed epithelial cells, with important implications for our understanding of epithelial cancers.     

A metabolic view of amphibian local community structure: the role of activation energy

In the context of the metabolic theory of ecology (MTE), the activation energy (E) reflects the temperature dependence of metabolism and organism performance in different activities, such as calling behavior. In this contribution we test the role of temperature in affecting local amphibian community structure, particularly the number of species engaged in calling behavior across a temperature gradient. Toward this aim, we compiled phenological calling activity for 52 Neotropical anuran communities. For each community we estimated the activation energy of calling behavior (E), finding values significantly higher than previous reports. A wide range of methodological issues with the potential to produce overestimated E‐values were shown to have no significant effect on reported E‐values, supporting a biological interpretation of their high values and of geographic trends. Further, a path analysis related variation in E among communities with communities’ phylogenetic structure, local environmental conditions, richness, and seasonality. The decrease of activation energy at higher latitudes and less productive environments suggests that amphibians’ activity could become more dependent of internal individuals’ resources once external sources are reduced. The increase in phylogenetic attraction with latitude points to a rise in the role of niche conservatism and community filtering operating over conserved traits. Finally, flexibility in activation energy related to amphibians’ calling could be an important and poorly recognized determinant of their thermal dependence. The temporal structuring of amphians’ communities was related here with the interplay between ecological and evolutionary processes operating at different scales. Our results support the view of activation energy as an important parameter of biodiversity organization, which unravels the effects of ecological and evolutionary processes on biodiversity structure and function.     

Clathrin: A good view of a shapely leg

The crystal structure of an amino-terminal fragment of the clathrin heavy chain has recently been determined, revealing a globular β-propeller domain attached by an α-zig-zag connecting rod to the heavy chain's distal segment. The structure sheds interesting new light on the design features of this versatile protein.     

Pursuing conception: a physician's experience with in-vitro fertilization.

Infertility is a common problem. Approximately one in seven North American couples will experience it, either by being unable to conceive after a year of trying or by experiencing recurrent miscarriages. A family physician outlines her experiences when being treated for infertility by in-vitro fertilization and embryo transfer.