355 research outputs found

    Energy Forecasting for Event Venues: Big Data and Prediction Accuracy

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    Advances in sensor technologies and the proliferation of smart meters have resulted in an explosion of energy-related data sets. These Big Data have created opportunities for development of new energy services and a promise of better energy management and conservation. Sensor-based energy forecasting has been researched in the context of office buildings, schools, and residential buildings. This paper investigates sensor-based forecasting in the context of event-organizing venues, which present an especially difficult scenario due to large variations in consumption caused by the hosted events. Moreover, the significance of the data set size, specifically the impact of temporal granularity, on energy prediction accuracy is explored. Two machine-learning approaches, neural networks (NN) and support vector regression (SVR), were considered together with three data granularities: daily, hourly, and 15 minutes. The approach has been applied to a large entertainment venue located in Ontario, Canada. Daily data intervals resulted in higher consumption prediction accuracy than hourly or 15-min readings, which can be explained by the inability of the hourly and 15-min models to capture random variations. With daily data, the NN model achieved better accuracy than the SVR; however, with hourly and 15-min data, there was no definitive dominance of one approach over another. Accuracy of daily peak demand prediction was significantly higher than accuracy of consumption prediction

    Infected Necrosis in Severe Pancreatitis - Combined Nonsurgical Multi-Drainage with Directed Transabdominal High-Volume Lavage in Critically Ill Patients

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    Background: Infection of pancreatic necrosis is a life-threatening complication during the course of acute pancreatitis. In critically ill patients, surgical or extended endoscopic interventions are associated with high morbidity and mortality. Minimally invasive procedures on the other hand are often insufficient in patients suffering from large necrotic areas containing solid or purulent material. We present a strategy combining percutaneous and transgastric drainage with continuous high-volume lavage for treatment of extended necroses and liquid collections in a series of patients with severe acute pancreatitis. Patients and Methods: Seven consecutive patients with severe acute pancreatitis and large confluent infected pancreatic necrosis were enrolled. In all cases, the first therapeutic procedure was placement of a CT-guided drainage catheter into the fluid collection surrounding peripancreatic necrosis. Thereafter, a second endosonographically guided drainage was inserted via the gastric or the duodenal wall. After communication between the separate drains had been proven, an external to internal directed high-volume lavage with a daily volume of 500 ml up to 2,000 ml was started. Results: In all patients, pancreatic necrosis/liquid collections could be resolved completely by the presented regime. No patient died in the course of our study. After initiation of the directed high-volume lavage, there was a significant clinical improvement in all patients. Double drainage was performed for a median of 101 days, high-volume lavage for a median of 41 days. Several endoscopic interventions for stent replacement were required (median 8). Complications such as bleeding or perforation could be managed endoscopically, and no subsequent surgical therapy was necessary. All patients could be dismissed from the hospital after a median duration of 78 days. Conclusion: This approach of combined percutaneous/endoscopic drainage with high-volume lavage shows promising results in critically ill patients with extended infected pancreatic necrosis and high risk of surgical intervention. Neither surgical nor endoscopic necrosectomy was necessary in any of our patients. Copyright (C) 2009 S. Karger AG, Basel and IA

    Subseafloor microbial communities in hydrogen-rich vent fluids from hydrothermal systems along the Mid-Cayman Rise

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    © The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Environmental Microbiology 18 (2016): 1970–1987, doi:10.1111/1462-2920.13173.Warm fluids emanating from hydrothermal vents can be used as windows into the rocky subseafloor habitat and its resident microbial community. Two new vent systems on the Mid-Cayman Rise each exhibits novel geologic settings and distinctively hydrogen-rich vent fluid compositions. We have determined and compared the chemistry, potential energy yielding reactions, abundance, community composition, diversity, and function of microbes in venting fluids from both sites: Piccard, the world's deepest vent site, hosted in mafic rocks; and Von Damm, an adjacent, ultramafic-influenced system. Von Damm hosted a wider diversity of lineages and metabolisms in comparison to Piccard, consistent with thermodynamic models that predict more numerous energy sources at ultramafic systems. There was little overlap in the phylotypes found at each site, although similar and dominant hydrogen-utilizing genera were present at both. Despite the differences in community structure, depth, geology, and fluid chemistry, energetic modelling and metagenomic analysis indicate near functional equivalence between Von Damm and Piccard, likely driven by the high hydrogen concentrations and elevated temperatures at both sites. Results are compared with hydrothermal sites worldwide to provide a global perspective on the distinctiveness of these newly discovered sites and the interplay among rocks, fluid composition and life in the subseafloor.National Aeronautics and Space Administration Grant Number: NNX09AB756; Alfred P. Sloan Foundation; NSF Grant Number: OCE10618

    Chemistry of hot springs along the Eastern Lau Spreading Center

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    Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Geochimica et Cosmochimica Acta 75 (2011): 1013-1038, doi:10.1016/j.gca.2010.12.008.The Eastern Lau Spreading Center (ELSC) is the southernmost part of the back-arc spreading axis in the Lau Basin, west of the Tonga trench and the active Tofua volcanic arc. Over its 397-km length it exhibits large and systematic changes in spreading rate, magmatic/tectonic processes, and proximity to the volcanic arc. In 2005 we collected 81 samples of vent water from six hydrothermal fields along the ELSC. The chemistry of these waters varies both within and between vent fields, in response to changes in substrate composition, temperature and pressure, pH, water/rock ratio, and input from magmatic gases and subducted sediment. Hot-spring temperatures range from 229Âș to 363ÂșC at the five northernmost fields, with a general decrease to the south that is reversed at the Mariner field. The southernmost field, Vai Lili, emitted water at up to 334°C in 1989 but had a maximum venting temperature of only 121ÂșC in 2005, due to waning activity and admixture of bottom seawater into the subseafloor plumbing system. Chloride varies both within fields and from one field to another, from a low of 528 mmol/kg to a high of 656 mmol/kg, and may be enriched by phase separation and/or leaching of Cl from the rock. Concentrations of the soluble elements K, Rb, Cs, and B likewise increase southward as the volcanic substrate becomes more silica-rich, especially on the Valu Fa Ridge. Iodine and ÎŽ7Li increase southward, and ÎŽ11B decreases as B increases, apparently in response to increased input from subducted sediment as the arc is approached. Species that decrease southward as temperature falls are Si, H2S, Li, Na/Cl, Fe, Mn, and 87Sr/86Sr, whereas pH, alkalinity, Ca, and Sr increase. Oxygen isotopes indicate a higher water/rock ratio in the three systems on Valu Fa Ridge, consistent with higher porosity in more felsic volcanic rocks. Vent waters at the Mariner vent field on the Valu Fa Ridge are significantly hotter, more acid and metal-rich, less saline, and richer in dissolved gases and other volatiles, including H2S, CO2, and F, than the other vent fields, consistent with input of magmatic gases. The large variations in geologic and geophysical parameters produced by back-arc spreading along the ELSC, which exceed those along mid-ocean ridge spreading axes, produce similar large variations in the composition of vent waters, and thus provide new insights into the processes that control the chemistry of submarine hot springs.We thank the U.S. National Science Foundation and its RIDGE 2000 Program for funding this study via grants OCE0241826 (to MJM), OCE0242902 (to PJM), OCE0241796 (to JSS, MKT), and OCE0242088 (to CGW), as well as the Deep Ocean Exploration Institute at WHOI (to GP, ER)

    Effect of Cyclooxygenase(COX)-1 and COX-2 inhibition on furosemide-induced renal responses and isoform immunolocalization in the healthy cat kidney

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    BACKGROUND: The role of cyclooxygenase(COX)-1 and COX-2 in the saluretic and renin-angiotensin responses to loop diuretics in the cat is unknown. We propose in vivo characterisation of isoform roles in a furosemide model by administering non-steroidal anti-inflammatory drugs (NSAIDs) with differing selectivity profiles: robenacoxib (COX-2 selective) and ketoprofen (COX-1 selective). RESULTS: In this four period crossover study, we compared the effect of four treatments: placebo, robenacoxib once or twice daily and ketoprofen once daily concomitantly with furosemide in seven healthy cats. For each period, urine and blood samples were collected at baseline and within 48 h of treatment starting. Plasma renin activity (PRA), plasma and urinary aldosterone concentrations, glomerular filtration rate (GFR) and 24 h urinary volumes, electrolytes and eicosanoids (PGE(2), 6-keto-PGF1(α,) TxB(2)), renal injury biomarker excretions [N-acetyl-beta-D-glucosaminidase (NAG) and Gamma-Glutamyltransferase] were measured. Urine volume (24 h) and urinary sodium, chloride and calcium excretions increased from baseline with all treatments. Plasma creatinine increased with all treatments except placebo, whereas GFR was significantly decreased from baseline only with ketoprofen. PRA increased significantly with placebo and once daily robenacoxib and the increase was significantly higher with placebo compared to ketoprofen (10.5 ± 4.4 vs 4.9 ± 5.0 ng ml(−1) h(−1)). Urinary aldosterone excretion increased with all treatments but this increase was inhibited by 75 % with ketoprofen and 65 % with once daily robenacoxib compared to placebo. Urinary PGE(2) excretion decreased with all treatments and excretion was significantly lower with ketoprofen compared to placebo. Urinary TxB(2) excretion was significantly increased from baseline only with placebo. NAG increased from baseline with all treatments. Immunohistochemistry on post-mortem renal specimens, obtained from a different group of cats that died naturally of non-renal causes, suggested constitutive COX-1 and COX-2 co-localization in many renal structures including the macula densa (MD). CONCLUSIONS: These data suggest that both COX-1 and COX-2 could generate the signal from the MD to the renin secreting cells in cats exposed to furosemide. Co-localization of COX isoenzymes in MD cells supports the functional data reported here. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12917-015-0598-z) contains supplementary material, which is available to authorized users

    Prospective assessment of patient-reported outcomes and estradiol and drug concentrations in patients experiencing toxicity from adjuvant aromatase inhibitors

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    PURPOSE: Aromatase inhibitors (AI), which decrease circulating estradiol concentrations in post-menopausal women, are associated with toxicities that limit adherence. Approximately one-third of patients will tolerate a different AI after not tolerating the first. We report the effect of crossover from exemestane to letrozole or vice versa on patient-reported outcomes (PROs) and whether the success of crossover is due to lack of estrogen suppression. METHODS: Post-menopausal women enrolled on a prospective trial initiating AI therapy for early-stage breast cancer were randomized to exemestane or letrozole. Those that discontinued for intolerance were offered protocol-directed crossover to the other AI after a washout period. Changes in PROs, including pain [Visual Analog Scale (VAS)] and functional status [Health Assessment Questionnaire (HAQ)], were compared after 3 months on the first versus the second AI. Estradiol and drug concentrations were measured. RESULTS: Eighty-three patients participated in the crossover protocol, of whom 91.3% reported improvement in symptoms prior to starting the second AI. Functional status worsened less after 3 months with the second AI (HAQ mean change AI #1: 0.2 [SD 0.41] vs. AI #2: -0.05 [SD 0.36]; p = 0.001); change in pain scores was similar between the first and second AI (VAS mean change AI #1: 0.8 [SD 2.7] vs. AI #2: -0.2 [SD 2.8]; p = 0.19). No statistical differences in estradiol or drug concentrations were found between those that continued or discontinued AI after crossover. CONCLUSIONS: Although all AIs act via the same mechanism, a subset of patients intolerant to one AI report improved PROs with a different one. The mechanism of this tolerance remains unknown, but does not appear to be due to non-adherence to, or insufficient estrogen suppression by, the second AI

    New Opportunities and Untapped Scientific Potential in the Abyssal Ocean

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    The abyssal ocean covers more than half of the Earth’s surface, yet remains understudied and underappreciated. In this Perspectives article, we mark the occasion of the Deep Submergence Vehicle Alvin’s increased depth range (from 4500 to 6500 m) to highlight the scientific potential of the abyssal seafloor. From a geologic perspective, ultra-slow spreading mid-ocean ridges, Petit Spot volcanism, transform faults, and subduction zones put the full life cycle of oceanic crust on display in the abyss, revealing constructive and destructive forces over wide ranges in time and space. Geochemically, the abyssal pressure regime influences the solubility of constituents such as silica and carbonate, and extremely high-temperature fluid-rock reactions in the shallow subsurface lead to distinctive and potentially unique geochemical profiles. Microbial residents range from low-abundance, low-energy communities on the abyssal plains to fast growing thermophiles at hydrothermal vents. Given its spatial extent and position as an intermediate zone between coastal and deep hadal settings, the abyss represents a lynchpin in global-scale processes such as nutrient and energy flux, population structure, and biogeographic diversity. Taken together, the abyssal ocean contributes critical ecosystem services while facing acute and diffuse anthropogenic threats from deep-sea mining, pollution, and climate change

    Diverse styles of submarine venting on the ultraslow spreading Mid-Cayman Rise

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    Author Posting. © The Authors, 2010. This is the author's version of the work. It is posted here by permission of National Academy of Sciences for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences of the United States of America 107 (2010): 14020-14025, doi:10.1073/pnas.1009205107.Thirty years after the first discovery of high-temperature submarine venting, the vast majority of the global Mid Ocean Ridge remains unexplored for hydrothermal activity. Of particular interest are the world’s ultra-slow spreading ridges which were the last to be demonstrated to host high-temperature venting, but may host systems particularly relevant to pre-biotic chemistry and the origins of life. Here we report first evidence for diverse and very deep hydrothermal vents along the ~110 km long, ultra-slow spreading Mid-Cayman Rise. Our data indicate that the Mid- Cayman Rise hosts at least three discrete hydrothermal sites, each representing a different type of water-rock interaction, including both mafic and ultra-mafic systems and, at ~5000 m, the deepest known hydrothermal vent. Although submarine hydrothermal circulation, in which seawater percolates through and reacts with host lithologies, occurs on all mid-ocean ridges, the diversity of vent-types identified here and their relative geographic isolation make the Mid-Cayman Rise unique in the oceans. These new sites offer prospects for: an expanded range of vent-fluid compositions; varieties of abiotic organic chemical synthesis and extremophile microorganisms; and unparalleled faunal biodiversity - all in close proximity.This research was funded through NASA (ASTEP) and WHOI (Ocean Ridge Initiative)
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