1,678 research outputs found

    Compressing Inertial Motion Data in Wireless Sensing Systems ā€“ An Initial Experiment

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    The use of wireless inertial motion sensors, such as accelerometers, for supporting medical care and sportā€™s training, has been under investigation in recent years. As the number of sensors (or their sampling rates) increases, compressing data at source(s) (i.e. at the sensors), i.e. reducing the quantity of data that needs to be transmitted between the on-body sensors and the remote repository, would be essential especially in a bandwidth-limited wireless environment. This paper presents a set of compression experiment results on a set of inertial motion data collected during running exercises. As a starting point, we selected a set of common compression algorithms to experiment with. Our results show that, conventional lossy compression algorithms would achieve a desirable compression ratio with an acceptable time delay. The results also show that the quality of the decompressed data is within acceptable range

    The Endogenous Cannabinoid Anandamide Inhibits Cromakalim-Activated K+ Currents in Follicle-Enclosed Xenopus Oocytes

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    The effect of the endogenous cannabinoid anandamide on K+ currents activated by the ATP-sensitive potassium (KATP) channel opener cromakalim was investigated in follicle-enclosed Xenopus oocytes using the two-electrode voltage-clamp technique. Anandamide (1ā€“90 Ī¼M) reversibly inhibited cromakalim-induced K+ currents, with an IC50 value of 8.1 Ā± 2 Ī¼M. Inhibition was noncompetitive and independent of membrane potential. Coapplication of anandamide with the cannabinoid type 1 (CB1) receptor antagonist N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboximide hydrochloride (SR 141716A) (1 Ī¼M), the CB2 receptor antagonist N-[(1S)endo-1,3,3-trimethyl bicyclo heptan-2-yl]-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-pyrazole-3-carboxamide (SR144528) (1 Ī¼M), or pertussis toxin (5 Ī¼g/ml) did not alter the inhibitory effect of anandamide, suggesting that known cannabinoid receptors are not involved in anandamide inhibition of K+ currents. Similarly, neither the amidohydrolase inhibitor phenylmethylsulfonyl fluoride (0.2 mM) nor the cyclooxygenase inhibitor indomethacin (5 Ī¼M) affected anandamide inhibition of K+ currents, suggesting that the effects of anandamide are not mediated by its metabolic products. In radioligand binding studies, anandamide inhibited the specific binding of the KATP ligand [3H]glibenclamide in the oocyte microsomal fractions, with an IC50 value of 6.3 Ā± 0.4 Ī¼M. Gonadotropin-induced oocyte maturation and the cromakalim-acceleration of progesterone-induced oocyte maturation were significantly inhibited in the presence of 10 Ī¼M anandamide. Collectively, these results indicate that cromakalim-activated K+ currents in follicular cells of Xenopus oocytes are modulated by anandamide via a cannabinoid receptor-independent mechanism and that the inhibition of these channels by anandamide alters the responsiveness of oocytes to gonadotropin and progesterone

    Investigating the Lagged Relationship between Smap Soil Moisture and Live Fuel Moisture in California, USA

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    Live fuel moisture (LFM), defined as the ratio between water in the fresh biomass out of the dry biomass, is a vital measurement of vegetation water content and flammability. In this study, we investigated the dynamics of in-situ measurement of LFM at all the active sites in California, USA and revealed the difference between evergreen forest and shrub/scrub, the two dominant land cover types in California\u27s fire-prone regions. We found that LFM of evergreen forest responses to soil moisture increase later than shrub/scrub, due to a later occurrence of major precipitation, a lower air temperature, and the different plant physiology. The comparison between SMAP L-band radiometer soil moisture and LFM showed that the lag between the rise in soil moisture and the response from LFM was much longer in evergreen forest. Compared with the evergreen forest, LFM of shrub/scrub was more sensitive to the inter-annual variability of soil moisture due to plant physiology and air temperature

    The Nonpsychoactive Cannabinoid Cannabidiol Inhibits 5-Hydroxytryptamine3A Receptor-Mediated Currents in Xenopus laevis Oocytes

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    The effect of the plant-derived nonpsychotropic cannabinoid, cannabidiol (CBD), on the function of hydroxytryptamine (5-HT)3A receptors expressed in Xenopus laevis oocytes was investigated using two-electrode voltage-clamp techniques. CBD reversibly inhibited 5-HT (1 Ī¼M)-evoked currents in a concentration-dependent manner (IC50 = 0.6 Ī¼M). CBD (1 Ī¼M) did not alter specific binding of the 5-HT3A antagonist [3H]3-(5-methyl-1H-imidazol-4-yl)-1-(1-methylindol-3-yl)propan-1-one (GR65630), in oocytes expressing 5-HT3A receptors. In the presence of 1 Ī¼M CBD, the maximal 5-HT-induced currents were also inhibited. The EC50 values were 1.2 and 1.4 Ī¼M, in the absence and presence of CBD, indicating that CBD acts as a noncompetitive antagonist of 5-HT3 receptors. Neither intracellular BAPTA injection nor pertussis toxin pretreatment (5 Ī¼g/ml) altered the CBD-evoked inhibition of 5-HT-induced currents. CBD inhibition was inversely correlated with 5-HT3A expression levels and mean 5-HT3 receptor current density. Pretreatment with actinomycin D, which inhibits protein transcription, decreased the mean 5-HT3 receptor current density and increased the magnitude of CBD inhibition. These data demonstrate that CBD is an allosteric inhibitor of 5-HT3 receptors expressed in X. laevis oocytes. They further suggest that allosteric inhibition of 5-HT3 receptors by CBD may contribute to its physiological roles in the modulation of nociception and emesis

    Cholecystokinin B-type Receptors Mediate a G-Protein-Dependent Depolarizing Action of Sulphated Cholecystokinin Ocatapeptide (CCK-8s) on Rodent Neonatal Spinal Ventral Horn Neurons

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    Reports of cholecystokinin (CCK) binding and expression of CCK receptors in neonatal rodent spinal cord suggest that CCK may influence neuronal excitability. In patch-clamp recordings from 19/21 ventral horn motoneurons in neonatal (PN 5ā€“12 days) rat spinal cord slices, we noted a slowly rising and prolonged membrane depolarization induced by bath-applied sulfated CCK octapeptide (CCK-8s; 1 Ī¼M), blockable by the CCKB receptor antagonist L-365,260 (1 Ī¼M). Responses to nonsulfated CCK-8 or CCK-4 were significantly weaker. Under voltage clamp (VH āˆ’65 mV), 22/24 motoneurons displayed a CCK-8s-induced tetrodotoxin-resistant inward current [peak: āˆ’136 Ā± 28 pA] with a similar time course, mediated via reduction in a potassium conductance. In 29/31 unidentified neurons, CCK-8s induced a significantly smaller inward current (peak: āˆ’42.8 Ā± 5.6 pA), and I-V plots revealed either membrane conductance decrease with net inward current reversal at 101.3 Ā± 4.4 mV (n = 16), membrane conductance increase with net current reversing at 36.1 Ā± 3.8 mV (n = 4), or parallel shift (n = 9). Intracellular GTP-Ī³-S significantly prolonged the effect of CCK-8s (n = 6), whereas GDP-Ī²-S significantly reduced the CCK-8s response (n = 6). Peak inward currents were significantly reduced after 5-min perfusion with N-ethylmaleimide. In isolated neonatal mouse spinal cord preparations, CCK-8s (30ā€“300 nM) increased the amplitude and discharge of spontaneous depolarizations recorded from lumbosacral ventral roots. These observations imply functional postsynaptic G-protein-coupled CCKB receptors are prevalent in neonatal rodent spinal cord

    Cellular and molecular targets of menthol actions

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    Ā© 2017 Oz, El Nebrisi, Yang, Howarth and Al Kury. Menthol belongs to monoterpene class of a structurally diverse group of phytochemicals found in plant-derived essential oils. Menthol is widely used in pharmaceuticals, confectionary, oral hygiene products, pesticides, cosmetics, and as a flavoring agent. In addition, menthol is known to have antioxidant, anti-inflammatory, and analgesic effects. Recently, there has been renewed awareness in comprehending the biological and pharmacological effects of menthol. TRP channels have been demonstrated to mediate the cooling actions of menthol. There has been new evidence demonstrating that menthol can significantly influence the functional characteristics of a number of different kinds of ligand and voltage-gated ion channels, indicating that at least some of the biological and pharmacological effects of menthol can be mediated by alterations in cellular excitability. In this article, we examine the results of earlier studies on the actions of menthol with voltage and ligand-gated ion channels

    Inhibition of Human Ī±7 Nicotinic Acetylcholine Receptors by Cyclic Monoterpene Carveol

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    Cyclic monoterpenes are a group of phytochemicals with antinociceptive, local anesthetic, and anti-inflammatory actions. Effects of cyclic monoterpenes including vanilin, pulegone, eugenole, carvone, carvacrol, carveol, thymol, thymoquinone, menthone, and limonene were investigated on the functional properties of the cloned Ī±7 subunit of the human nicotinic acetylcholine receptor expressed in Xenopus oocytes. Monoterpenes inhibited the Ī±7 nicotinic acetylcholine receptor in the order carveol\u3ethymoquinone\u3ecarvacrol\u3ementhone\u3ethymol\u3elimonene\u3eeugenole\u3epulegoneā‰„carvoneā‰„vanilin. Among the monoterpenes, carveol showed the highest potency on acetylcholine-induced responses, with IC50 of 8.3 ĀµM. Carveol-induced inhibition was independent of the membrane potential and could not be reversed by increasing the concentration of acetylcholine. In line with functional experiments, docking studies indicated that cyclic monoterpenes such as carveol may interact with an allosteric site located in the Ī±7 transmembrane domain. Our results indicate that cyclic monoterpenes inhibit the function of human Ī±7 nicotinic acetylcholine receptors, with varying potencies

    Nuclear Stopping as A Probe to In-medium Nucleon-nucleon Cross Section in Intermediate Energy Heavy Ion Collisions

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    Using an isospin-dependent quantum molecular dynamics, nuclear stopping in intermediate heavy ion collisions has been studied. The calculation has been done for colliding systems with different neutron-proton ratios in beam energy ranging from 15MeV/u to 150MeV/u. It is found that, in the energy region from above Fermi energy to 150MeV/u, nuclear stopping is very sensitive to the isospin dependence of in-medium nucleon-nucleon cross section, but insensitive to symmetry potential. From this investigation, we propose that nuclear stopping can be used as a new probe to extract the information on the isospin dependence of in-medium nucleon-nucleon cross section in intermediate energy heavy ion collisions
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