Rumination in bipolar disorder: evidence for an unquiet mind

Depression in bipolar disorder has long been thought to be a state characterized by mental inactivity. However, recent research demonstrates that patients with bipolar disorder engage in rumination, a form of self-focused repetitive cognitive activity, in depressed as well as in manic states. While rumination has long been associated with depressed states in major depressive disorder, the finding that patients with bipolar disorder ruminate in manic states is unique to bipolar disorder and challenges explanations put forward for why people ruminate. We review the research on rumination in bipolar disorder and propose that rumination in bipolar disorder, in both manic and depressed states, reflects executive dysfunction. We also review the neurobiology of bipolar disorder and recent neuroimaging studies of rumination, which is consistent with our hypothesis that the tendency to ruminate reflects executive dysfunction in bipolar disorder. Finally, we relate the neurobiology of rumination to the neurobiology of emotion regulation, which is disrupted in bipolar disorder

A Sensor for Embedded Stress Measure of Concrete: Testing and Material Heterogeneity Issues

Concrete is well known to be a heterogeneous material that is usually considered homogeneous only referring to a scale of several centimetres. This characteristic makes measuring stresses inside concrete a particularly difficult task. Strains can be measured using several well-known devices. Nevertheless, it is almost impossible to derive a correct estimation of the stress within a concrete structure starting from strain measures as the modulus of elasticity is variable and unknown and creep strains superimpose elastic ones. A preliminary experimental campaign performed to test a stress sensor with the dimensions of a coin to be embedded in concrete is described in the present paper. The effects external applied load are measured comparing the results of short-term loading test performed directly on the sensor and on concrete specimens