Cover Image,Volume 74, Issue 8

The cover image, by Marisa Skaljac et al., is based on the Research Article Fitness costs of infection with Serratia symbiotica are associated with greater susceptibility to insecticides in the pea aphid Acyrthosiphon pisum, DOI: 10.1002/ps.4881 . Image Credit: Marisa Skaljac.

     

Direct atom-resolved imaging of oxides and their grain boundaries

Using high-resolution transmission electron microscopy, we obtained structure images of strontium titanate (SrTiO3) with a clearly resolved oxygen sublattice along different crystallographic directions in the bulklattice and for a Sigma3 tilt grain boundary. Comparison with image simulations showed that the grain boundary contains oxygen vacancies. Measurements of atom displacements near the grain boundary revealed close correspondence with theoretical calculations.     

Regulation of fasted blood glucose by resistin

The association between obesity and diabetes supports an endocrine role for the adipocyte in maintaining glucose homeostasis. Here we report that mice lacking the adipocyte hormone resistin exhibit low blood glucose levels after fasting, due to reduced hepatic glucose production. This is partly mediated by activation of adenosine monophosphate-activated protein kinase and decreased expression of gluconeogenic enzymes in the liver. The data thus support a physiological function for resistin in the maintenance of blood glucose during fasting. Remarkably, lack of resistin diminishes the increase in post-fast blood glucose normally associated with increased weight, suggesting a role for resistin in mediating hyperglycemia associated with obesity.