376 research outputs found
Measurement of Skin Friction Drag on Hydrophobic Silica Aerogel Surfaces with Potential Application to Technical Swimsuit Design
The goal of this project was to fabricate and test a prototype technical swimsuit (low-drag suit worn by swimmers in their most important races) that utilized the hydrophobic properties of silica aerogels. This process involved coating a preexisting suit with aerogel material and completing the build of the newly redesigned water channel at Union College. To evaluate performance of materials, surface drag testing of airfoils coated in aerogel materials was performed using a dynamometer in the water channel. Several additions were made to the water channel in order to reduce variation in drag results. Variation was successfully decreased from 134% to 8.7%. Results from the aerogel drag testing were compared to similar tests run on airfoils covered in racing suits that are worn by professional swimmers. Drag coefficients ranging from 0.037 to 0.040 were calculated using dynamometer drag readings. Sessile drop tests were performed to measure the contact angle of a drop of water 2 μL on the surface of each material. Contact angles greater than or equal to 135 degrees were found for all items tested. It was found that aerogel coated suits performed comparably to racing suits in drag testing and outperformed racing suits in contact angle testing
Cleveland Opportunity Corridor Project Reader-Friendly Environmental Impact Statement
How do we make technical information understandable and appealing to a non-technical audience? The Cleveland Opportunity Corridor project in Ohio involves building an urban boulevard with traffic signals to connect Cleveland’s interstate system to University Circle—one of the city’s major economic centers and employment hubs. The HNTB Corporation wrote a reader-friendly EIS that is practical, easy to understand, and visually appealing. This presentation outlines the motivation for developing such a document and how to create one
Factors Influencing Largemouth Bass Recruitment: Implications for the Illinois Management and Stocking Program
Annual Progress Report issued August 2002; NOTE: Two different reports numbered 02/06
were issued from the CAE.Report issued on: August 2002INHS Technical Report prepared for Division of Fisheries Illinois Department of Natural
Resource
Survival and Growth of Three Geographically Distinct Stocks of Muskellunge Introduced into Midwestern Reservoirs
Muskellunge Esox masquinongy management programs often rely on stocking to create and maintain populations. In many instances, a native and nearby stocking source is unavailable or a genetically suitable brood source is unclear. Genetic differences among stocks of Muskellunge may influence survival and growth when introduced into novel environments. Consequently, the selection of a suitable brood source can be difficult and possibly critical to the success of Muskellunge stocking programs. We examined differences in long-term survival and growth among introduced Muskellunge stocks from the Ohio and upper Mississippi River drainages and a mixed-origin Illinois broodstock population in three Illinois reservoirs. Catch per unit effort (CPUE) from spring modified-fyke netting suggested that the upper Mississippi River drainage stock at ages 3 and 4 persisted at lower relative abundance compared to conspecifics; however, low lake- and stock-specific catches of older ages precluded robust CPUE comparisons among stocks. Apparent survival, estimated from mark-recapture data with the Cormack-Jolly-Seber open population model, differed among stocks I-year poststocking, with the upper Mississippi River drainage stock exhibiting markedly lower survival compared to conspecifics. Annual variation in survival to age 1.5 was related to water temperature at stocking, fish size at stocking, first winter temperatures, and first summer temperatures. However, survival did not differ among stocks for Muskellunge age 2 and older, indicating that important factors structuring long-term survival exert their effects most strongly in the first year poststocking. Despite overall low survival of Muskellunge from the upper Mississippi River drainage, males that survived exhibited a slight growth advantage compared to conspecifics. No growth advantage was observed for upper Mississippi River drainage stock females. Our findings suggest that stock selection in addition to environmental conditions can influence survival of introduced Muskellunge and subsequent contribution to the fishery
Tinnitus as a Measure of Salicylate Toxicity in the Overdose Setting
Introduction: The development of tinnitus and/or hearing loss (THL) in patients receiving chronic salicylate therapy has been demonstrated. However, to date, little scientific data validates this relationship in the large single overdose setting.Objective: To correlate salicylate levels in patients with the subjective complaint of THL, following an acute salicylate overdose.Methods: A retrospective chart review of cases of acute salicylate toxicity and THL reported to the Illinois Poison Control Center (IPC) from 2001-2002 was performed. Data abstracted included age, gender, ingestion time, salicylate levels, and arterial blood gases.Results: Ninety-nine cases of THL were reviewed and analyzed with mean age of 23.7 years (SD: 10.9), 30.3% male, and 82.2% intentional overdoses. The average dose ingested was 20.0 grams (SD:20.2) and the mean time from ingestion to medical care was 12.4 hours (SD: 11.1). The mean initial ASA level was 48.3 mg/dl (SD: 16.4) with 86.9% having initial level ≥ 30mg/dl and 40.4% ≥ 50 mg/dl. 85.9% of cases presented to the hospital with their ASA level at or past peak. The mean pH was 7.45, pO2 = 108, pCO2 = 28.0, and HCO3 = 19.9.Conclusion: In this limited study, 85.9% of patients presenting with tinnitus and/or hearing loss following a single salicylate ingestion had initial salicylate levels at or past their peak and 86.9% were in the toxic range
Linking modern pollen accumulation rates to biomass: Quantitative vegetation reconstruction in the western Klamath Mountains, NW California, USA
Quantitative reconstructions of vegetation abundance from sediment-derived pollen systems provide unique insights into past ecological conditions. Recently, the use of pollen accumulation rates (PAR, grains cm−2 year−1) has shown promise as a bioproxy for plant abundance. However, successfully reconstructing region-specific vegetation dynamics using PAR requires that accurate assessments of pollen deposition processes be quantitatively linked to spatially-explicit measures of plant abundance. Our study addressed these methodological challenges. Modern PAR and vegetation data were obtained from seven lakes in the western Klamath Mountains, California. To determine how to best calibrate our PAR-biomass model, we first calculated the spatial area of vegetation where vegetation composition and patterning is recorded by changes in the pollen signal using two metrics. These metrics were an assemblage-level relevant source area of pollen (aRSAP) derived from extended R-value analysis (sensu Sugita, 1993) and a taxon-specific relevant source area of pollen (tRSAP) derived from PAR regression (sensu Jackson, 1990). To the best of our knowledge, aRSAP and tRSAP have not been directly compared. We found that the tRSAP estimated a smaller area for some taxa (e.g. a circular area with a 225 m radius for Pinus) than the aRSAP (a circular area with a 625 m radius). We fit linear models to relate PAR values from modern lake sediments with empirical, distance-weighted estimates of aboveground live biomass (AGLdw) for both the aRSAP and tRSAP distances. In both cases, we found that the PARs of major tree taxa – Pseudotsuga, Pinus, Notholithocarpus, and TCT (Taxodiaceae, Cupressaceae, and Taxaceae families) – were statistically significant and reasonably precise estimators of contemporary AGLdw. However, predictions weighted by the distance defined by aRSAP tended to be more precise. The relative root-mean squared error for the aRSAP biomass estimates was 9% compared to 12% for tRSAP. Our results demonstrate that calibrated PAR-biomass relationships provide a robust method to infer changes in past plant biomass
An improved database of coastal flooding in the United Kingdom from 1915 to 2016
Coastal flooding caused by extreme sea levels can produce devastating and wide-ranging consequences. The ‘SurgeWatch’ v1.0 database systematically documents and assesses the consequences of historical coastal flood events around the UK. The original database was inevitably biased due to the inconsistent spatial and temporal coverage of sea-level observations utilised. Therefore, we present an improved version integrating a variety of ‘soft’ data such as journal papers, newspapers, weather reports, and social media. SurgeWatch2.0 identifies 329 coastal flooding events from 1915 to 2016, a more than fivefold increase compared to the 59 events in v1.0. Moreover, each flood event is now ranked using a multi-level categorisation based on inundation, transport disruption, costs, and fatalities: from 1 (Nuisance) to 6 (Disaster). For the 53 most severe events ranked Category 3 and above, an accompanying event description based upon the Source-Pathway-Receptor-Consequence framework was produced. Thus, SurgeWatch v2.0 provides the most comprehensive and coherent historical record of UK coastal flooding. It is designed to be a resource for research, planning, management and education
Spatial and temporal analysis of extreme sea level and storm surge events around the coastline of the UK
In this paper we analyse the spatial footprint and temporal clustering of extreme sea level and skew surge events around the UK coast over the last 100 years (1915-2014). The vast majority of the extreme sea level events are generated by moderate, rather than extreme skew surges, combined with spring astronomical high tides. We distinguish four broad categories of spatial footprints of events and the distinct storm tracks that generated them. There have been rare events when extreme levels have occurred along two unconnected coastal regions during the same storm. The events that occur in closest succession (< 4 days) typically impact different stretches of coastline. The spring/neap tidal cycle prevents successive extreme sea level events from happening within 4-8 days. Finally, the 2013/14 season was highly unusual in the context of the last 100 years from an extreme sea level perspective
Electronic structure and superconductivity of the non-centrosymmetric Sn4As3
CAM and MJN acknowledge studentship funding from EPSRC under Grant no. EP/L015110/1. CMY and PW acknowledge funding through EP/S005005/1. CH acknowledges support by the Austrian Science Fund (FWF) Project No. P32144-N36 and the VSC-3 of the Vienna University of Technology. KSP, VAV, VMP, and AVM acknowledge support of the state assignment of the Ministry of Science and Higher Education of the Russian Federation (Project No. 0023-2019-0005).In a superconductor that lacks inversion symmetry, the spatial part of the Cooper pair wave function has a reduced symmetry, allowing for the mixing of spin-singlet and spin-triplet Cooper pairing channels and thus providing a pathway to a non-trivial superconducting state. Materials with a non-centrosymmetric crystal structure and with strong spin-orbit coupling are a platform to realize these possibilities. Here, we report the synthesis and characterisation of high quality crystals of Sn4As3, with non-centrosymmetric unit cell (R3m). We have characterised the normal and superconducting state using a range of methods. Angle-resolved photoemission spectroscopy shows a multiband Fermi surface and the presence of two surface states, confirmed by Density-functional theory calculations. Specific heat measurements reveal a superconducting critical temperature of Tc ∼ 1.14 K and an upper critical magnetic field of Hc ≈ 7 mT, which are both confirmed by ultra-low temperature scanning tunneling microscopy and spectroscopy. Scanning tunneling spectroscopy shows a fully formed superconducting gap, consistent with conventional s-wave superconductivity.Publisher PDFPeer reviewe
A conditional form of Bruton's tyrosine kinase is sufficient to activate multiple downstream signaling pathways via PLC Gamma 2 in B cells
BACKGROUND: Bruton's tyrosine kinase (Btk) is essential for B cell development and function. Mutations of Btk elicit X-linked agammaglobulinemia in humans and X-linked immunodeficiency in the mouse. Btk has been proposed to participate in B cell antigen receptor-induced signaling events leading to activation of phospholipase C-γ2 (PLCγ2) and calcium mobilization. However it is unclear whether Btk activation is alone sufficient for these signaling events, and whether Btk can activate additional pathways that do not involve PLCγ2. To address such issues we have generated Btk:ER, a conditionally active form of the kinase, and expressed it in the PLCγ2-deficient DT40 B cell line. RESULTS: Activation of Btk:ER was sufficient to induce multiple B cell signaling pathways in PLCγ2-sufficient DT40 cells. These included tyrosine phosphorylation of PLCγ2, mobilization of intracellular calcium, activation of extracellular signal-regulated kinase (ERK) and c-Jun NH(2)-terminal kinase (JNK) mitogen-activated protein kinase (MAPK) pathways, and apoptosis. In DT40 B cells deficient for PLCγ2, Btk:ER activation failed to induce the signaling events described above with the consequence that the cells failed to undergo apoptosis. CONCLUSIONS: These data suggest that Btk:ER regulates downstream signaling pathways primarily via PLCγ2 in B cells. While it is not known whether activated Btk:ER precisely mimics activated Btk, this conditional system will likely facilitate the dissection of the role of Btk and its family members in a variety of biological processes in many different cell types
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