285 research outputs found

    All Through the Love of You!

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    https://digitalcommons.library.umaine.edu/mmb-vp/3933/thumbnail.jp

    Passage Re-Ranking in Live QA NLP Pipelines with BERT

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    Passage ranking and document ranking are two common tasks in NLP. Many state of the art pipelines use BM25 to retrieve passages. The top results of this ranking are then re-ranked using a BERT transformer trained on the MS MARCO Passage data set. This system and variations have proved highly effective. In addition, questions and answers using BERT are also well explored topics. However, these systems are fundamentally limited by speed and resource consumption requirements. Given an arbitrary corpus and a collection of pre-trained models, we would like to prove that it is possible to create a live Question Answering machine without fine tuning for a particular topic. In particular, we employ a BERT re-ranker to find the first acceptable fit to pass to our QA transformer. This approach is fundamentally different from past research in that it is focused on first fit and not best fit. The goal of this research is to allow anyone to employ off the shelf components to create an effective, interactive question answering system

    Flexible, High-Speed, Small Satellite Production

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    Planet’s first mission is to image the entire land mass of the Earth every day in an effort to make global change visible, accessible, and actionable. To do this, Planet designs and builds highly capable Earth-imaging satellites and today operates the largest Earth-imaging fleet in history. To support this mission, Planet had to develop an adaptable concurrent product development cycle associated with a unique assembly and manufacturing line to support the quick production and delivery of satellites. This paper introduces how Planet achieved that objective by building multiple spacecraft design iterations concurrently and how Planet orchestrates a production line for speed, flexibility, and high throughput of satellite delivery in just over a few weeks

    Lactate-proton co-transport and its contribution to interstitial acidification during hypoxia in isolated rat spinal roots

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    Exposure of nervous tissue to hypoxia results in interstitial acidification. There is evidence for concomitant decrease in extracellular pH to the increase in tissue lactate. In the present study, we used double-barrelled pH-sensitive microelectrodes to investigate the link between lactate transport and acid-base homeostasis in isolated rat spinal roots. Addition of different organic anions to the bathing solution at constant bath pH caused transient alkaline shifts in extracellular pH; withdrawal of these compounds resulted in transient acid shifts in extracellular pH. With high anion concentrations (30 mM), the largest changes in extracellular pH were observed with propionate >l-lactate ≈ pyruvate >62; 2-hydroxy-2-methylpropionate. Changes in extracellular pH induced by 10 mMl- andd-lactate were of similar size. Lactate transport inhibitors α-cyano-4-hydroxycinnamic acid and 4,4′-dibenzamidostilbene-2,2′-disulphonic acid significantly reducedl-lactate-induced extracellular pH shifts without affecting propionate-induced changes in extracellular pH. Hypoxia produced an extracellular acidification that was strongly reduced in the presence of α-cyano-4-hydroxycinnamic acid and 4,4′-dibenzamidostilbene-2,2′-disulphonic acid. In contrast, amiloride and 4,4′-di-isothiocyanostilbene-2,2′-disulphonate were without effect on hypoxia-induced acid shifts. The results indicate the presence of a lactate-proton co-transporter in rat peripheral nerves. This transport system and not Na+/H+ or C1−/HCO−3 exchange seems to be the dominant mechanism responsible for interstitial acidification during nerve hypoxia

    [11C]flumazenil Binding Is Increased in a Dose-Dependent Manner with Tiagabine-Induced Elevations in GABA Levels

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    Evidence indicates that synchronization of cortical activity at gamma-band frequencies, mediated through GABA-A receptors, is important for perceptual/cognitive processes. To study GABA signaling in vivo, we recently used a novel positron emission tomography (PET) paradigm measuring the change in binding of the benzodiazepine (BDZ) site radiotracer [11C]flumazenil associated with increases in extracellular GABA induced via GABA membrane transporter (GAT1) blockade with tiagabine. GAT1 blockade resulted in significant increases in [11C]flumazenil binding potential (BPND) over baseline in the major functional domains of the cortex, consistent with preclinical studies showing that increased GABA levels enhance the affinity of GABA-A receptors for BDZ ligands. In the current study we sought to replicate our previous results and to further validate this approach by demonstrating that the magnitude of increase in [11C]flumazenil binding observed with PET is directly correlated with tiagabine dose. [11C]flumazenil distribution volume (VT) was measured in 18 healthy volunteers before and after GAT1 blockade with tiagabine. Two dose groups were studied (n = 9 per group; Group I: tiagabine 0.15 mg/kg; Group II: tiagabine 0.25 mg/kg). GAT1 blockade resulted in increases in mean (± SD) [11C]flumazenil VT in Group II in association cortices (6.8±0.8 mL g−1 vs. 7.3±0.4 mL g−1;p = 0.03), sensory cortices (6.7±0.8 mL g−1 vs. 7.3±0.5 mL g−1;p = 0.02) and limbic regions (5.2±0.6 mL g−1 vs. 5.7±0.3 mL g−1;p = 0.03). No change was observed at the low dose (Group I). Increased orbital frontal cortex binding of [11C]flumazenil in Group II correlated with the ability to entrain cortical networks (r = 0.67, p = 0.05) measured via EEG during a cognitive control task. These data provide a replication of our previous study demonstrating the ability to measure in vivo, with PET, acute shifts in extracellular GABA

    Photometric Calibration of the Swift Ultraviolet/Optical Telescope

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    We present the photometric calibration of the Swift UltraViolet/Optical Telescope (UVOT) which includes: optimum photometric and background apertures, effective area curves, colour transformations, conversion factors for count rates to flux, and the photometric zero points (which are accurate to better than 4 per cent) for each of the seven UVOT broadband filters. The calibration was performed with observations of standard stars and standard star fields that represent a wide range of spectral star types. The calibration results include the position dependent uniformity, and instrument response over the 1600-8000A operational range. Because the UVOT is a photon counting instrument, we also discuss the effect of coincidence loss on the calibration results. We provide practical guidelines for using the calibration in UVOT data analysis. The results presented here supersede previous calibration results.Comment: Minor improvements after referees report. Accepted for publication in MNRA

    Paper II: Calibration of the Swift ultraviolet/optical telescope

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    The Ultraviolet/Optical Telescope (UVOT) is one of three instruments onboard the Swift observatory. The photometric calibration has been published, and this paper follows up with details on other aspects of the calibration including a measurement of the point spread function with an assessment of the orbital variation and the effect on photometry. A correction for large scale variations in sensitivity over the field of view is described, as well as a model of the coincidence loss which is used to assess the coincidence correction in extended regions. We have provided a correction for the detector distortion and measured the resulting internal astrometric accuracy of the UVOT, also giving the absolute accuracy with respect to the International Celestial Reference System. We have compiled statistics on the background count rates, and discuss the sources of the background, including instrumental scattered light. In each case we describe any impact on UVOT measurements, whether any correction is applied in the standard pipeline data processing or whether further steps are recommended.Comment: Accepted for publication in MNRAS. 15 pages, 21 figures, 4 table

    Salbutamol for analgesia in renal colic : study protocol for a prospective, randomised, placebo-controlled phase II trial (SARC)

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    Background Renal colic is the pain experienced by a patient when a renal calculus (kidney stone) causes partial or complete obstruction of part of the renal outflow tract. The standard analgesic regimes for renal colic are often ineffective; in some studies, less than half of patients achieve complete pain relief, and a large proportion of patients require rescue analgesia within 4 h. Current analgesic regimes are also associated with significant side effects including nausea, vomiting, drowsiness and respiratory depression. It has been hypothesised that beta adrenoreceptor agonists, such as salbutamol, may reduce the pain of renal colic. They have been shown to impact a number of factors that target the physiological causes of pain in renal colic (ureteric spasm and increased peristalsis, increased pressure at the renal pelvis and prostaglandin release with inflammation). There is biological plausibility and a body of evidence sufficient to suggest that this novel treatment for the pain of renal colic should be taken to a phase II clinical trial. The aim of this trial is to test whether salbutamol is an efficacious analgesic adjunct when added to the standard analgesic regime for patients presenting to the ED with subsequently confirmed renal colic. Methods A phase II, randomised, placebo-controlled trial will be performed in an acute NHS Trust in the East Midlands. Patients presenting to the emergency department with pain requiring IV analgesia and working diagnosis of renal colic will be randomised to receive standard analgesia ± a single intravenous injection of Salbutamol. Secondary study objectives will explore the feasibility of conducting a larger, phase III trial. Discussion The trial will provide important information about the efficacy of salbutamol as an analgesic adjunct in renal colic. It will also guide the development of a definitive phase III trial to test the cost and clinical effectiveness of salbutamol as an analgesic adjunct in renal colic. Salbutamol benefits from widespread use across the health service for multiple indications, extensive staff familiarity and a good side effect profile; therefore, its potential use for pain relief may have significant benefits for patient care. Trial registration ISRCTN Registry ISRCTN14552440. Registered on 22 July 201
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