6 research outputs found

    Sounding out the river:Seismic and hydroacoustic monitoring of bedload transport

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    Seismological observations provide a non-invasive and continuous means for indirectly measuring fluvial bedload transport. A significant challenge remains in independently characterising the seismic signature of bedload transport from other sources such as turbulence. We present a unique dataset from an alluvial Scottish river, combining seismic data and hydroacoustic measurements, to analyse bedload transport during three high-flow events occurring within the same year. By studying three successive events, we assess the consistency of bedload transport thresholds in response to changing flow conditions and explore the presence of hysteresis in seismic data versus water level as an indicator of coarse bedload transport. Through the use of hydroacoustic data to independently characterise bedload transport, our findings reveal that bedload transport occurred during all three events but that the threshold for entrainment varied. These entrainment thresholds were influenced by antecedent events, with a drop of 15%–20% of the threshold flow depth following the largest of the three events. In agreement with recent studies, we also found that hysteresis in the seismic versus water level data is not sufficient for identifying and analysing bedload transport: Distinct hysteresis was only observed during the largest of the three events despite all events experiencing bedload transport as observed through the independent hydroacoustic data. Our work shows the value in combining independent datasets for long-term monitoring of bedload transport to understand the evolution in the thresholds of bedload motion, providing crucial information for effective river and land-use management in a changing climate with potentially impacted high-flow events

    Optical Tastebuds for Water Quality Testing

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    To achieve the UN Sustainable Development Goal of universal access to clean water and sanitation, we need to rethink centralized water systems with global net-zero carbon and sustainability in mind. One approach is to develop scalable off-grid systems that are reliable and easy to use and maintain. A major challenge for such systems is translating the standard laboratory-based monitoring of centralized systems to a more sustainable and scalable model for regularly and routinely monitoring system outputs, which consist of complex mixtures with varying concentrations of molecules and ions in water. Here, we demonstrate a preliminary sensor that, once fully developed, could allow for point-of-use measurements with a single output to monitor. Rather than developing multiple sensors to monitor the levels of each individual component in the water, our label-free, array-based design mimics the biological system of taste. The sensor is comprised of an array of nano-tastebuds made of tailored plasmonic metasurfaces. The combination of different signals from each nano-tastebud to the same sample yields a unique fingerprint for that sample. Through training, these fingerprints build an identification model. By integrating a fully developed sensor into decentralized water systems, we seek to provide non-expert end-users with an easy-to-read output capable of warning of imminent system failures

    Optical Tastebuds for Water Analysis

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    We demonstrate a preliminary nano-tastebud sensor comprised of tailored plasmonic metasurfaces that, once fully developed, could be integrated into water treatment facilities as an early warning system to warn of imminent system failures

    A cross-reactive plasmonic sensing array for drinking water assessment

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    The continuous monitoring of remote drinking water purification systems is a global challenge with direct consequences for human and environmental health. Here, we utilise a “nano-tastebud” sensor comprised of eight chemically-tailored plasmonic metasurfaces, for testing the composition of drinking water. Through undertaking a full chemometric analysis of the water samples and likely contaminants we were able to optimise the sensor specification to create an array of suitable tastebuds. By generating a unique set of optical responses for each water sample, we show that the array-based sensor can differentiate between untreated influent and treated effluent water with over 95% accuracy in flow and can detect compositional changes in distributed modified tap water. Once fully developed, this system could be integrated into water treatment facilities and distribution systems to monitor for changes in water composition

    Prolactin mediates long-term, seasonal rheostatic regulation of body mass in female mammals

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    A series of well-described anabolic and catabolic neuropeptides are known to provide short-term, homeostatic control of energy balance. The mechanisms that govern long-term, rheostatic control of regulated changes in energy balance are less well characterized. Using the robust and repeatable seasonal changes in body mass observed in Siberian hamsters, this report examined the role of prolactin in providing long-term rheostatic control of body mass and photoinduced changes in organ mass (ie, kidney, brown adipose tissue, uterine, and spleen). Endogenous circannual interval timing was observed after 4 months in a short photoperiod, indicated by a significant increase in body mass and prolactin mRNA expression in the pituitary gland. There was an inverse relationship between body mass and the expression of somatostatin (Sst) and cocaine- and amphetamine-regulated transcript (Cart). Pharmacological inhibition of prolactin release (via bromocriptine injection), reduced body mass of animals maintained in long photoperiods to winter–short photoperiod levels and was associated with a significant increase in hypothalamic Cart expression. Administration of ovine prolactin significantly increased body mass 24 hours after a single injection and the effect persisted after 3 consecutive daily injections. The data indicate that prolactin has pleiotropic effects on homeostatic sensors of energy balance (ie, Cart) and physiological effectors (ie, kidney, BAT). We propose that prolactin release from the pituitary gland acts as an output signal of the hypothalamic rheostat controller to regulate adaptive changes in body mass
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