A Genetic Algorithm for Optimal Design of Model Output Following Control

ＡＧｅｎｅｔｉｃＡｌｇｏｒｉｔｈｍｆｏｒＯｐｔｉｍａｌＤｅｓｉｇｎｏｆＭｏｄｅｌＯｕｔｐｕｔＦｏｌｌｏｗｉｎｇＣｏｎｔｒｏｌ￥ＺＨＡＮＧＸｉａｏｊｕｎ；ＹＡＭＡＮＥＹｕｚｏ（ＡｓｈｉｋａｇａＩｎｓｔｉｔｕｔｅｏｆＴｅｃｈｎｏｌｏｇｙ，Ａｓｈｉｋａｇａ...     

Heat activation of TRPM5 underlies thermal sensitivity of sweet taste

TRPM5, a cation channel of the TRP superfamily, is highly expressed in taste buds of the tongue, where it has a key role in the perception of sweet, umami and bitter tastes. Activation of TRPM5 occurs downstream of the activation of G-protein-coupled taste receptors and is proposed to generate a depolarizing potential in the taste receptor cells. Factors that modulate TRPM5 activity are therefore expected to influence taste. Here we show that TRPM5 is a highly temperature-sensitive, heat-activated channel: inward TRPM5 currents increase steeply at temperatures between 15 and 35 degrees C. TRPM4, a close homologue of TRPM5, shows similar temperature sensitivity. Heat activation is due to a temperature-dependent shift of the activation curve, in analogy to other thermosensitive TRP channels. Moreover, we show that increasing temperature between 15 and 35 degrees C markedly enhances the gustatory nerve response to sweet compounds in wild-type but not in Trpm5 knockout mice. The strong temperature sensitivity of TRPM5 may underlie known effects of temperature on perceived taste in humans, including enhanced sweetness perception at high temperatures and 'thermal taste', the phenomenon whereby heating or cooling of the tongue evoke sensations of taste in the absence of tastants.     

A Robust Model Following Control for Plant withUncertain Parameters Based on Genetic Algorithm

1IntroductionModelfollowingcontrolsystemaredesignedtomaketheoutputsoftheplanthavingdesiredperformance.Thegeneralstepsofcontrolsystemdesignare:thefirstistomodeltheplants,andthencontrolschemesaredesignedbasedonthereferencemodel.However,forarealcontrolledplantthereedestsomedifficultiestodevelopanexactmodelsuchasobtainingtheaccuratesystemparameters.Someparametersaretime-varyingandfunctionsofthesystemstates.Whenwedesignacontrolsystem,theseuncertaintieshavetobeconsidered.Therearemanyresearchreports…     

Neuroscience: rewiring the adult brain

Any analysis of plastic reorganization at a neuronal locus needs a veridical measure of changes in the functional output--that is, spiking responses of the neurons in question. In a study of the effect of retinal lesions on adult primary visual cortex (V1), Smirnakis et al. propose that there is no cortical reorganization. Their results are based, however, on BOLD (blood-oxygen-level-dependent) fMRI (functional magnetic resonance imaging), which provides an unreliable gauge of spiking activity. We therefore question their criterion for lack of plasticity, particularly in the light of the large body of earlier work that demonstrates cortical plasticity.