7 research outputs found

    On shape dependence of holographic entanglement entropy in AdS4/CFT3 with Lifshitz scaling and hyperscaling violation

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    We study the divergent terms and the finite term in the expansion of the holographic entanglement entropy as the ultraviolet cutoff vanishes for smooth spatial regions having arbitrary shape, when the gravitational background is a four dimensional asymptotically Lifshitz spacetime with hyperscaling violation, in a certain range of the hyperscaling parameter. Both static and time dependent backgrounds are considered. For the coefficients of the divergent terms and for the finite term, analytic expressions valid for any smooth entangling curve are obtained. The analytic results for the finite terms are checked through a numerical analysis focussed on disks and ellipses

    Optical switching between long-lived states of opsin transmembrane voltage sensors

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    Opsin-based transmembrane voltage sensors (OTVSs) are membrane proteins increasingly used in optogenetic applications to measure voltage changes across cellular membranes. In order to better understand the photophysical properties of OTVSs, we used a combination of UV-Vis absorption, fluorescence and FT-Raman spectroscopy to characterize QuasAr2 and NovArch, two closely related mutants derived from the proton pump archaerhodopsin-3 (AR3). We find both QuasAr2 and NovArch can be optically cycled repeatedly between O-like and M-like states using 5-min exposure to red (660 nm) and near-UV (405 nm) light. Longer red-light exposure resulted in the formation of a long-lived photoproduct similar to pink membrane, previously found to be a photoproduct of the BR O intermediate with a 9-cis retinylidene chromophore configuration. However, unlike QuasAr2 whose O-like state is stable in the dark, NovArch exhibits an O-like state which slowly partially decays in the dark to a stable M-like form with a deprotonated Schiff base and a 13-cis,15-anti retinylidene chromophore configuration. These results reveal a previously unknown complexity in the photochemistry of OTVSs including the ability to optically switch between different long-lived states. The possible molecular basis of these newly discovered properties along with potential optogenetic and biotechnological applications are discussed.Solid state NMR/Biophysical Organic Chemistr

    Delimitazione di aree boschive montane percorse dal fuoco mediante immagini satellitari ad alta risoluzione geometrica

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    Abstract: In this paper we present a remote sensing technique, based on very high spatial resolution Quickbird satellite data, aimed to map burnt forested areas located in alpine environment hit by winter fires occurred in Lombardia Region in the 2005 year. Quickbird satellite images have a spatial resolution of 2.5 m and are characterized by 4 spectral bands covering the regions of blue, green, red and near infrared. Burnt areas were automatically extracted by using an object oriented classification combined with a connectivity algorithm developed with the aim to join burnt isolates pixel with the main body of the area hit by fire. The proposed algorithm is based on the exploitation of a Gaussian function that produces a degree of membership to be burnt for every pixel not classified as burnt by means of the preliminary automatic classification. The membership function is established on the base of the spatial distance and it decrease according the full width at half maximum of the Gaussian function. The produced maps have been compared with the burnt area boundaries obtained by means of field survey based on GPS measurements; this allowed us to estimate the goodness of the proposed method. The comparison between the results produced by the connectivity algorithm and the reference measured in ground showed high degrees of accuracy with errors ranging from 3 to 20%

    Delineation of burnt mountain forest areas by high-resolution satellite images

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