The Experts below are selected from a list of 3957 Experts worldwide ranked by ideXlab platform
Paul A. Garrity - One of the best experts on this subject based on the ideXlab platform.
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an internal thermal Sensor controlling temperature preference in drosophila
Nature, 2008Co-Authors: Fumika N. Hamada, Mark Rosenzweig, Kyeongjin Kang, Antonio Ghezzi, Stefan R. Pulver, Timothy J Jegla, Paul A. GarrityAbstract:In large animals the Sensors used to monitor environmental temperature are found at the periphery of the body, and the prevailing wisdom has been that their location in small animals would be the same. For instance it was assumed that insects would sense ambient temperature via their antennae. But a surprise finding in Drosophila has identified the large heat-responsive neurons that detect ambient temperature, and they are located internally, in the brain. The four anterior cell neurons respond to warmth by activating dTrpA1 ion channels, presumably alerting the fly to seek more hospitable climes. These channels are potential targets for the disruption of thermal preference behaviours in insect pests and disease vectors. It is shown here that flies sense ambient warmth not via their antennae, but rather by a small set of neurons in the brain. These 'AC' neurons in Drosophila are sensitive to warmth due to the expression of the warmth-activated ion channel dTrpA1. Animals from flies to humans are able to distinguish subtle gradations in temperature and show strong temperature preferences1,2,3,4. Animals move to environments of optimal temperature and some manipulate the temperature of their surroundings, as humans do using clothing and shelter. Despite the ubiquitous influence of environmental temperature on animal behaviour, the neural circuits and strategies through which animals select a preferred temperature remain largely unknown. Here we identify a small set of warmth-activated anterior cell (AC) neurons located in the Drosophila brain, the function of which is critical for preferred temperature selection. AC neuron activation occurs just above the fly’s preferred temperature and depends on dTrpA1, an ion channel that functions as a Molecular Sensor of warmth. Flies that selectively express dTrpA1 in the AC neurons select normal temperatures, whereas flies in which dTrpA1 function is reduced or eliminated choose warmer temperatures. This internal warmth-sensing pathway promotes avoidance of slightly elevated temperatures and acts together with a distinct pathway for cold avoidance to set the fly’s preferred temperature. Thus, flies select a preferred temperature by using a thermal sensing pathway tuned to trigger avoidance of temperatures that deviate even slightly from the preferred temperature. This provides a potentially general strategy for robustly selecting a narrow temperature range optimal for survival.
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An internal thermal Sensor controlling temperature preference in Drosophila
Nature, 2008Co-Authors: Fumika N. Hamada, Mark Rosenzweig, Kyeongjin Kang, Antonio Ghezzi, Stefan R. Pulver, Timothy J Jegla, Paul A. GarrityAbstract:Animals from flies to humans are able to distinguish subtle gradations in temperature and show strong temperature preferences. Animals move to environments of optimal temperature and some manipulate the temperature of their surroundings, as humans do using clothing and shelter. Despite the ubiquitous influence of environmental temperature on animal behaviour, the neural circuits and strategies through which animals select a preferred temperature remain largely unknown. Here we identify a small set of warmth-activated anterior cell (AC) neurons located in the Drosophila brain, the function of which is critical for preferred temperature selection. AC neuron activation occurs just above the fly's preferred temperature and depends on dTrpA1, an ion channel that functions as a Molecular Sensor of warmth. Flies that selectively express dTrpA1 in the AC neurons select normal temperatures, whereas flies in which dTrpA1 function is reduced or eliminated choose warmer temperatures. This internal warmth-sensing pathway promotes avoidance of slightly elevated temperatures and acts together with a distinct pathway for cold avoidance to set the fly's preferred temperature. Thus, flies select a preferred temperature by using a thermal sensing pathway tuned to trigger avoidance of temperatures that deviate even slightly from the preferred temperature. This provides a potentially general strategy for robustly selecting a narrow temperature range optimal for survival.
Ozgur B. Akan - One of the best experts on this subject based on the ideXlab platform.
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Coverage and throughput analysis for FRET-based mobile Molecular Sensor/actor nanonetworks
Nano Communication Networks, 2014Co-Authors: Murat Kuscu, Ozgur B. AkanAbstract:Abstract Nanonetworks are envisaged to expand the capabilities of single nanomachines by enabling collaboration through communication between them. Forster Resonance Energy Transfer (FRET) observed among fluorescent molecules is a promising means of high-rate and reliable information transfer between single fluorophore-based nanoscale Molecular machines. Recent theoretical studies have underlined its practicality for mobile ad hoc nanonetworks consisting of functionalized fluorescent molecules. In this study, we focus on the spatial characteristics of FRET-Based Mobile Molecular Sensor/Actor Nanonetworks (FRET-MSAN) by investigating the network performance in terms of communication coverage, network throughput and information propagation rate through extensive Monte Carlo simulations. The effect of fundamental system parameters related to FRET and to the mobility of the network nodes on the network performance is revealed. The results of the simulations indicate that the throughput and propagation rate as a function of distance from the information source are well-fitted by exponential curves. We also observe that the impact of FRET mechanism suppresses the effect of Brownian motion of network nodes on the exciton mobility.
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A Communication Theoretical Analysis of FRET-Based Mobile Ad Hoc Molecular Nanonetworks
IEEE Transactions on NanoBioscience, 2014Co-Authors: Murat Kuscu, Ozgur B. AkanAbstract:Nanonetworks refer to a group of nanosized machines with very basic operational capabilities communicating to each other in order to accomplish more complex tasks such as in-body drug delivery, or chemical defense. Realizing reliable and high-rate communication between these nanomachines is a fundamental problem for the practicality of these nanonetworks. Recently, we have proposed a Molecular communication method based on Förster Resonance Energy Transfer (FRET) which is a nonradiative excited state energy transfer phenomenon observed among fluorescent molecules, i.e., fluorophores. We have modeled the FRET-based communication channel considering the fluorophores as single-Molecular immobile nanomachines, and shown its reliability at high rates, and practicality at the current stage of nanotechnology. In this study, for the first time in the literature, we investigate the network of mobile nanomachines communicating through FRET. We introduce two novel mobile Molecular nanonetworks: FRET-based mobile Molecular Sensor/actor nanonetwork (FRET-MSAN) which is a distributed system of mobile fluorophores acting as Sensor or actor node; and FRET-based mobile ad hoc Molecular nanonetwork (FRET-MAMNET) which consists of fluorophore-based nanotransmitter, nanoreceivers and nanorelays. We model the single message propagation based on birth-death processes with continuous time Markov chains. We evaluate the performance of FRET-MSAN and FRET-MAMNET in terms of successful transmission probability and mean extinction time of the messages, system throughput, channel capacity and achievable communication rates.
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FRET-based mobile Molecular nanonetworks
2013 12th Annual Mediterranean Ad Hoc Networking Workshop (MED-HOC-NET), 2013Co-Authors: Murat Kuscu, Ozgur B. AkanAbstract:Nanonetworks refer to a group of nano-sized machines with very basic operational capabilities communicating to each other in order to accomplish more complex tasks such as in-body drug delivery, or chemical defense. Realizing reliable and high-rate communication between these nanomachines is a fundamental problem for the practicality of these nanonetworks. Recently, we have proposed a Molecular communication method based on Förster resonance energy transfer (FRET) which is a nonradiative excited state energy transfer phenomenon observed among fluorescent molecules, i.e., fluorophores. We have modeled the FRET-based communication channel considering the fluorophores as single-Molecular immobile nanomachines, and shown its reliability at high rates, and practicality at the current stage of nanotechnology. In this study, we focus on network of mobile nanomachines communicating through FRET. We introduce two novel mobile Molecular nanonetworks: FRET-based mobile Molecular Sensor/actor nanonetwork (FRET-MSAN) which is a distributed system of mobile fluorophores acting as Sensor or actor node; and FRET-based mobile ad hoc Molecular nanonetwork (FRET-MAMNET) which consists of fluorophore-based nanotransmitter, nanoreceivers and nanorelays. We model the single message propagation exploiting the SIR model of epidemics. We derive closed form expressions for the probability of the actor nodes to detect a message generated on the Sensor nodes in FRET-MSAN, and for the average detection time of the transmitted message by the nanoreceivers in FRET-MAMNET. We numerically evaluate the performance of these networks in terms of reliability and transmission delay for varying number of nanonodes and varying size of nanomachines, as well as, for several FRET-related parameters.
Fumika N. Hamada - One of the best experts on this subject based on the ideXlab platform.
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an internal thermal Sensor controlling temperature preference in drosophila
Nature, 2008Co-Authors: Fumika N. Hamada, Mark Rosenzweig, Kyeongjin Kang, Antonio Ghezzi, Stefan R. Pulver, Timothy J Jegla, Paul A. GarrityAbstract:In large animals the Sensors used to monitor environmental temperature are found at the periphery of the body, and the prevailing wisdom has been that their location in small animals would be the same. For instance it was assumed that insects would sense ambient temperature via their antennae. But a surprise finding in Drosophila has identified the large heat-responsive neurons that detect ambient temperature, and they are located internally, in the brain. The four anterior cell neurons respond to warmth by activating dTrpA1 ion channels, presumably alerting the fly to seek more hospitable climes. These channels are potential targets for the disruption of thermal preference behaviours in insect pests and disease vectors. It is shown here that flies sense ambient warmth not via their antennae, but rather by a small set of neurons in the brain. These 'AC' neurons in Drosophila are sensitive to warmth due to the expression of the warmth-activated ion channel dTrpA1. Animals from flies to humans are able to distinguish subtle gradations in temperature and show strong temperature preferences1,2,3,4. Animals move to environments of optimal temperature and some manipulate the temperature of their surroundings, as humans do using clothing and shelter. Despite the ubiquitous influence of environmental temperature on animal behaviour, the neural circuits and strategies through which animals select a preferred temperature remain largely unknown. Here we identify a small set of warmth-activated anterior cell (AC) neurons located in the Drosophila brain, the function of which is critical for preferred temperature selection. AC neuron activation occurs just above the fly’s preferred temperature and depends on dTrpA1, an ion channel that functions as a Molecular Sensor of warmth. Flies that selectively express dTrpA1 in the AC neurons select normal temperatures, whereas flies in which dTrpA1 function is reduced or eliminated choose warmer temperatures. This internal warmth-sensing pathway promotes avoidance of slightly elevated temperatures and acts together with a distinct pathway for cold avoidance to set the fly’s preferred temperature. Thus, flies select a preferred temperature by using a thermal sensing pathway tuned to trigger avoidance of temperatures that deviate even slightly from the preferred temperature. This provides a potentially general strategy for robustly selecting a narrow temperature range optimal for survival.
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An internal thermal Sensor controlling temperature preference in Drosophila
Nature, 2008Co-Authors: Fumika N. Hamada, Mark Rosenzweig, Kyeongjin Kang, Antonio Ghezzi, Stefan R. Pulver, Timothy J Jegla, Paul A. GarrityAbstract:Animals from flies to humans are able to distinguish subtle gradations in temperature and show strong temperature preferences. Animals move to environments of optimal temperature and some manipulate the temperature of their surroundings, as humans do using clothing and shelter. Despite the ubiquitous influence of environmental temperature on animal behaviour, the neural circuits and strategies through which animals select a preferred temperature remain largely unknown. Here we identify a small set of warmth-activated anterior cell (AC) neurons located in the Drosophila brain, the function of which is critical for preferred temperature selection. AC neuron activation occurs just above the fly's preferred temperature and depends on dTrpA1, an ion channel that functions as a Molecular Sensor of warmth. Flies that selectively express dTrpA1 in the AC neurons select normal temperatures, whereas flies in which dTrpA1 function is reduced or eliminated choose warmer temperatures. This internal warmth-sensing pathway promotes avoidance of slightly elevated temperatures and acts together with a distinct pathway for cold avoidance to set the fly's preferred temperature. Thus, flies select a preferred temperature by using a thermal sensing pathway tuned to trigger avoidance of temperatures that deviate even slightly from the preferred temperature. This provides a potentially general strategy for robustly selecting a narrow temperature range optimal for survival.
Bernard Valeur - One of the best experts on this subject based on the ideXlab platform.
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Rhod-5N as a Fluorescent Molecular Sensor of Cadmium(II) Ion
Journal of Fluorescence, 2008Co-Authors: Mathieu Soibinet, Vincent Souchon, Isabelle Leray, Bernard ValeurAbstract:The photophysical and complexing properties of Rhod-5N (commercially available) in MOPS buffer are reported. This fluorescent Molecular Sensor consists of a BAPTA chelating moiety bound to a rhodamine fluorophore. Its fluorescence quantum yield is low and a drastic enhancement of fluorescence intensity upon cation binding was observed. Special attention was paid to the complexation with Cd2+, a well known toxic metal ion. Possible interference with other metal ions (Na+, K+, Mg2+, Ca2+, Zn2+, Pb2+) was examined. Rhod-5N was found to be highly selective of Cd2+ over those interfering cations except Pb2+. The limit of detection is 3.1 μg l−1.
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selective detection of cesium by a water soluble fluorescent Molecular Sensor based on a calix 4 arene bis crown 6 ether
Chemical Communications, 2006Co-Authors: Vincent Souchon, Isabelle Leray, Bernard ValeurAbstract:A tetrasulfonated calixarene with two appended crowns, each including a dioxycoumarin fluorophore, is highly soluble in water and shows excellent selectivity for cesium ions.
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A highly sensitive and selective fluorescent Molecular Sensor for Pb(II) based on a calix[4]arene bearing four dansyl groups
Chemical Communications, 2003Co-Authors: Rémi Métivier, Isabelle Leray, Bernard ValeurAbstract:A new fluorescent Molecular Sensor based on a calix[4]arene bearing four dansyl groups exhibits very efficient binding in acetonitrile–water for lead and the changes of emission properties allows a detection limit of 4 µg L−1.
Murat Kuscu - One of the best experts on this subject based on the ideXlab platform.
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Coverage and throughput analysis for FRET-based mobile Molecular Sensor/actor nanonetworks
Nano Communication Networks, 2014Co-Authors: Murat Kuscu, Ozgur B. AkanAbstract:Abstract Nanonetworks are envisaged to expand the capabilities of single nanomachines by enabling collaboration through communication between them. Forster Resonance Energy Transfer (FRET) observed among fluorescent molecules is a promising means of high-rate and reliable information transfer between single fluorophore-based nanoscale Molecular machines. Recent theoretical studies have underlined its practicality for mobile ad hoc nanonetworks consisting of functionalized fluorescent molecules. In this study, we focus on the spatial characteristics of FRET-Based Mobile Molecular Sensor/Actor Nanonetworks (FRET-MSAN) by investigating the network performance in terms of communication coverage, network throughput and information propagation rate through extensive Monte Carlo simulations. The effect of fundamental system parameters related to FRET and to the mobility of the network nodes on the network performance is revealed. The results of the simulations indicate that the throughput and propagation rate as a function of distance from the information source are well-fitted by exponential curves. We also observe that the impact of FRET mechanism suppresses the effect of Brownian motion of network nodes on the exciton mobility.
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A Communication Theoretical Analysis of FRET-Based Mobile Ad Hoc Molecular Nanonetworks
IEEE Transactions on NanoBioscience, 2014Co-Authors: Murat Kuscu, Ozgur B. AkanAbstract:Nanonetworks refer to a group of nanosized machines with very basic operational capabilities communicating to each other in order to accomplish more complex tasks such as in-body drug delivery, or chemical defense. Realizing reliable and high-rate communication between these nanomachines is a fundamental problem for the practicality of these nanonetworks. Recently, we have proposed a Molecular communication method based on Förster Resonance Energy Transfer (FRET) which is a nonradiative excited state energy transfer phenomenon observed among fluorescent molecules, i.e., fluorophores. We have modeled the FRET-based communication channel considering the fluorophores as single-Molecular immobile nanomachines, and shown its reliability at high rates, and practicality at the current stage of nanotechnology. In this study, for the first time in the literature, we investigate the network of mobile nanomachines communicating through FRET. We introduce two novel mobile Molecular nanonetworks: FRET-based mobile Molecular Sensor/actor nanonetwork (FRET-MSAN) which is a distributed system of mobile fluorophores acting as Sensor or actor node; and FRET-based mobile ad hoc Molecular nanonetwork (FRET-MAMNET) which consists of fluorophore-based nanotransmitter, nanoreceivers and nanorelays. We model the single message propagation based on birth-death processes with continuous time Markov chains. We evaluate the performance of FRET-MSAN and FRET-MAMNET in terms of successful transmission probability and mean extinction time of the messages, system throughput, channel capacity and achievable communication rates.
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FRET-based mobile Molecular nanonetworks
2013 12th Annual Mediterranean Ad Hoc Networking Workshop (MED-HOC-NET), 2013Co-Authors: Murat Kuscu, Ozgur B. AkanAbstract:Nanonetworks refer to a group of nano-sized machines with very basic operational capabilities communicating to each other in order to accomplish more complex tasks such as in-body drug delivery, or chemical defense. Realizing reliable and high-rate communication between these nanomachines is a fundamental problem for the practicality of these nanonetworks. Recently, we have proposed a Molecular communication method based on Förster resonance energy transfer (FRET) which is a nonradiative excited state energy transfer phenomenon observed among fluorescent molecules, i.e., fluorophores. We have modeled the FRET-based communication channel considering the fluorophores as single-Molecular immobile nanomachines, and shown its reliability at high rates, and practicality at the current stage of nanotechnology. In this study, we focus on network of mobile nanomachines communicating through FRET. We introduce two novel mobile Molecular nanonetworks: FRET-based mobile Molecular Sensor/actor nanonetwork (FRET-MSAN) which is a distributed system of mobile fluorophores acting as Sensor or actor node; and FRET-based mobile ad hoc Molecular nanonetwork (FRET-MAMNET) which consists of fluorophore-based nanotransmitter, nanoreceivers and nanorelays. We model the single message propagation exploiting the SIR model of epidemics. We derive closed form expressions for the probability of the actor nodes to detect a message generated on the Sensor nodes in FRET-MSAN, and for the average detection time of the transmitted message by the nanoreceivers in FRET-MAMNET. We numerically evaluate the performance of these networks in terms of reliability and transmission delay for varying number of nanonodes and varying size of nanomachines, as well as, for several FRET-related parameters.