No abstract

Conventional dynamic light scattering (DLS) using a CCD camera as optical area detector (here we called Image Dynamic Light Scattering method, for the data acquired by images ) has been developed successfully. We present a model experiment in a micro-channel to study flowing Brownian motion systems of polystyrene latex particles by using Image Dynamic Light Scattering method (IDLS). The modified correlation function proposed by Chowdhury et al, which is applied to the analysis of extracting the size and velocity of laminar flowing particulate dispersions, is used in the paper to obtain the particle size from the scattered light signals. The new method allows for much shorter measurement time compared to conventional DLS. As the inversion algorithm of polydisperse system is yet very complex, the measurement of the paper is for monodisperse polystyrene latex particles.

No abstract

An important aspect of biological intelligence is the ability of quick task switching. Such ability may be realized through a neural system equipped with functionally specialized modules subserving each task. The orbitofrontal cortex (OFC) harbors a persistent circuit supporting economic decisions under different contexts. To examine the specialization of this circuit, we contrasted the coding of the same neurons in the OFC of rhesus monkeys under economic choice (EC) and single-attribute choice (SC). In EC, OFC neurons largely encoded offer value, chosen value and choice outcome in goods space. Strikingly, these neurons were tuned out in SC while a complementary set of neurons encoded SC-related variables in a spatial reference frame. Moreover, in EC, neurons encoding the same value-related variable are anatomically clustered and the noise correlation among these neurons dropped significantly when the animal switched from EC to SC, suggesting altered functional organization. Thus, specialized modules in the OFC may support cognitive flexibility in choice.

No abstract