Implementation of novel sensors on underwater gliders

Around a quarter of global anthropogenic carbon emissions have been absorbed by the ocean. Underwater gliders have been identified as important tools for gathering information related to climate change and ocean acidification processes. The REP14 -MED experiment involved the deployment of eleven gliders in the northwestern Mediterranean Sea; one of these had an experimental ion sensitive field effect transistor (ISFET) sensor attached. A comparison between pH observed by the glider and ship during the deployment indicated problems with the sensor accuracy and stability. Sunlight caused an apparent sensor pH decrease of up to 0.1 close to the surface around local noon. The pH corrected for drift, temperature, and pressure is presented with other ocean variables measured by the glider. The timing of the phytoplankton spring bloom in the northwestern Mediterranean Sea varies year-on-year. A glider with an ISFET pH sensor was deployed close to the BOUSSOLE mooring site. This deployment offered a second opportunity to test the ISFET sensor with improvements. Similarly to during the REP14 -MED experiment, ISFET pH measurements were corrected for drift, temperature and pressure effects. Measurements at the BOUSSOLE mooring indicated that the spring bloom started around March 19. Mean net community production (N) rates were estimated from the glider dissolved oxygen concentrations, as well as glider and buoy dissolved inorganic carbon concentrations derived using other parameters. N ranged between -82±317 mmol m-2 d-1 and 460±870 mmol m-2 d-1. Horizontal spatial scales of variability highlight physical and biogeochemical processes, and are useful for designing ocean observing systems. Spatial scales of variability were estimated from semivariograms using glider measurements. Spatial scales of variability were mostly small at depths affected by biology, and large at depths affected by largescale processes, such as weather, although this was not true in every case. Some direction-dependency was found, which may be related to ocean currents, or the density of glider meridional measurements. keywords: pH sensor; underwater gliders; biogeochemistry; net community production; spatial scales; northwestern Mediterranean Se

In-line measurement of the surface texture of rolls using long slender piezoresistive microprobes

Long slender piezoresistive silicon microprobes are a new type of sensor for measurement of surface roughness. Their advantage is the ability to measure at speeds of up to 15 mm/s, which is much faster than conventional stylus probes. The drawbacks are their small measurement range and tendency to break easily when deflected by more than the allowed range of 1 mm. In this article, previously developed microprobes were tested in the laboratory to evaluate their metrological properties, then tested under industrial conditions. There are several industrial measurement applications in which microprobes are useful. Measurement of the roughness of paper machine rolls was selected for testing in this study. The integration of a microprobe into an existing roll measurement device is presented together with the measurement results. The results are promising, indicating that measurements using a microprobe can give useful data on the grinding process

Synthesis and activity of a novel Autotaxin inhibitor-Icodextrin conjugate

© Copyright 2018 American Chemical Society. Autotaxin is an extracellular phospholipase D that catalyses the hydrolysis of lysophosphatidyl choline (LPC) to generate the bioactive lipid lysophosphatidic acid (LPA). Autotaxin has been implicated in many pathological processes relevant to cancer. Intraperitoneal administration of an autotaxin inhibitor may benefit patients with ovarian cancer, however low molecular mass compounds are known to be rapidly cleared from the peritoneal cavity. Icodextrin is a polymer that is already in clinical use because it is slowly eliminated from the peritoneal cavity. Herein we report conjugation of the autotaxin inhibitor HA-155 to icodextrin. The conjugate inhibits autotaxin activity (IC50 = 0.86 ± 0.13 μg mL-1) and reduces cell migration. Conjugation of the inhibitor increased its solubility, decreased its membrane permeability and improved its intraperitoneal retention in mice. These observations demonstrate the first application of icodextrin as a covalently-bonded drug delivery platform with potential use in the treatment of ovarian cancer

Working with Gravitational-Wave sky localizations: new methods and implementations

International audience; The era of multi-messenger astrophysics with Gravitational Waves (GW) requires the exploration and development of suitable methods and tools for real-time analysis as well as post-processing activities. The irregular and complex shapes of the GW sky localizations represent a new challenge for observational astronomers, who need to work with fast tiling, catalog queries, transient localizations, visibility and sky map comparisons. Here we show how gravitational-wave sky maps can be easily and efficiently visualized and processed using Multi-Order Coverage (MOC) maps. These maps are based on HEALPix sky tessellation which uses both Python language and the recent implementation in Aladin Desktop/Lite. In addition to this, we describe a specific interactive script, named GWsky, that we developed to effectively tile the sky localization of a gravitational-wave event providing accurate telescope pointings. We also show applications of these methods and tools for educational purposes in Virtual Reality Apps, high resolution images, and basic sonification of the GW sky maps.Finally, we describe possible evolutions of such implementations when three or more ground-based interferometers will be involved in a gravitational-wave source localization (i.e. Virgo,LIGO–Hanford, LIGO–Livingston, KAGRA, LIGO–India) with a corresponding increase of the sky map resolution

High-resolution observations in the Western Mediterranean Sea: The REP14-MED experiment

The observational part of the REP14-MED experiment was conducted in June 2014 in the Sardo-Balearic Sea west of Sardinia Island (Western Mediterranean Sea). Two research vessels collected high-resolution oceanographic data by means of hydrographic casts, towed systems, and underway measurements. In addition, a vast amount of data was provided by a fleet of 11 gliders, time series were available from moored instruments, and information on Lagrangian flow patterns were obtained from surface drifters and one profiling float. The spatial resolution of the observations encompasses a spectrum over four orders of magnitude from O(101 m) to O(105 m), and the time series from the moored instruments cover a spectral range of five orders from O(101 s) to O(106 s). The objective of this article is to provide an overview of the huge data set which is utilized by various ongoing studies, focusing on (i) sub-mesoscale and mesoscale pattern analyses, (ii) operational forecasting in terms of the development and assessment of sampling strategies, assimilation methods, and model validation, (iii) modeling the variability of the ocean, and (iv) testing of new payloads for gliders

VHEE FLASH sparing effect measured at CLEAR, CERN with DNA damage of pBR322 plasmid as a biological endpoint

Ultra-high dose rate (UHDR) irradiation has been shown to have a sparing effect on healthy tissue, an effect known as ‘FLASH’. This effect has been studied across several radiation modalities, including photons, protons and clinical energy electrons, however, very little data is available for the effect of FLASH with Very High Energy Electrons (VHEE). pBR322 plasmid DNA was used as a biological model to measure DNA damage in response to Very High Energy Electron (VHEE) irradiation at conventional (0.08 Gy/s), intermediate (96 Gy/s) and ultra-high dose rates (UHDR, (2 × 109 Gy/s) at the CERN Linear Electron Accelerator (CLEAR) user facility. UHDRs were used to determine if the biological FLASH effect could be measured in the plasmid model, within a hydroxyl scavenging environment. Two different concentrations of the hydroxyl radical scavenger Tris were used in the plasmid environment to alter the proportions of indirect damage, and to replicate a cellular scavenging capacity. Indirect damage refers to the interaction of ionising radiation with molecules and species to generate reactive species which can then attack DNA. UHDR irradiated plasmid was shown to have significantly reduced amounts of damage in comparison to conventionally irradiated, where single strand breaks (SSBs) was used as the biological endpoint. This was the case for both hydroxyl scavenging capacities. A reduced electron energy within the VHEE range was also determined to increase the DNA damage to pBR322 plasmid. Results indicate that the pBR322 plasmid model can be successfully used to explore and test the effect of UHDR regimes on DNA damage. This is the first study to report FLASH sparing with VHEE, with induced damage to pBR322 plasmid DNA as the biological endpoint. UHDR irradiated plasmid had reduced amounts of DNA single-strand breaks (SSBs) in comparison with conventional dose rates. The magnitude of the FLASH sparing was a 27% reduction in SSB frequency in a 10 mM Tris environment and a 16% reduction in a 100 mM Tris environment

Traveling slippery patches produce thickness-scale folds in ice sheets

Large, complex stratigraphic folds that rise as high as 60% of the local ice thickness have been observed in ice sheets on Antarctica and Greenland. Here we show that ice deformation caused by heterogeneous and time-variable basal sliding can produce the observed structures. We do this using a thermomechanical ice sheet model in which sliding occurs when the base approaches the melting point and slippery patches develop. These slippery patches emerge and travel downstream because of a feedback between ice deformation, vertical flow, and temperature. Our model produces the largest overturned structures, comparable to observations, when the patches move at about the ice column velocity. We conclude that the history of basal slip conditions is recorded in the ice sheet strata. These basal conditions appear to be dynamic and heterogeneous even in the slow-flowing interior regions of large ice sheets