19,395 research outputs found

    Primary Care Validation of a Single-Question Alcohol Screening Test

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    BACKGROUND Unhealthy alcohol use is prevalent but under-diagnosed in primary care settings. OBJECTIVE To validate, in primary care, a single-item screening test for unhealthy alcohol use recommended by the National Institute on Alcohol Abuse and Alcoholism (NIAAA). DESIGN Cross-sectional study. PARTICIPANTS Adult English-speaking patients recruited from primary care waiting rooms. MEASUREMENTS Participants were asked the single screening question, "How many times in the past year have you had X or more drinks in a day?", where X is 5 for men and 4 for women, and a response of >1 is considered positive. Unhealthy alcohol use was defined as the presence of an alcohol use disorder, as determined by a standardized diagnostic interview, or risky consumption, as determined using a validated 30-day calendar method. MAIN RESULTS Of 394 eligible primary care patients, 286 (73%) completed the interview. The single-question screen was 81.8% sensitive (95% confidence interval (CI) 72.5% to 88.5%) and 79.3% specific (95% CI 73.1% to 84.4%) for the detection of unhealthy alcohol use. It was slightly more sensitive (87.9%, 95% CI 72.7% to 95.2%) but was less specific (66.8%, 95% CI 60.8% to 72.3%) for the detection of a current alcohol use disorder. Test characteristics were similar to that of a commonly used three-item screen, and were affected very little by subject demographic characteristics. CONCLUSIONS. The single screening question recommended by the NIAAA accurately identified unhealthy alcohol use in this sample of primary care patients. These findings support the use of this brief screen in primary care.National Institute on Alcohol Abuse and Alcoholism (R01-AA010870

    An assessment of the mantle and slab components in the magmas of an oceanic arc volcano: Raoul Volcano, Kermadec arc

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    Raoul Volcano occupies a simple oceanic subduction setting in the northern part of the Kermadec arc on the Pacific–Australian convergent plate boundary. The primary inputs to the magmatic system that feeds the volcano are a subduction component derived from the subducting old Pacific oceanic lithosphere and its veneer of pelagic sediment, and the overlying peridotitic mantle wedge. Conservative trace elements that are very incompatible during mantle melting are relatively depleted in Raoul lavas indicating a source that has been depleted during an earlier melting event. Major element co-variations indicate magma genesis by 25% near fractional melting of a mantle source that is weakly depleted (2% melt extraction) relative to a fertile MORB source. An important influence on the composition of the mantle component is progressive melt extraction coupled with minimal advection of fresh material into the sub-arc zone followed by melt extraction from a melting column beneath the spreading centre of an adjacent back arc basin. High field strength element and rare earth element systematics indicate involvement of a subduction-related component of constant composition. Two fluid components can be distinguished, one enriched in large ion lithophile elements inferred to be an aqueous fluid that is continuously added to the ascending melt column and the other a less mobile fluid that transfers Th. A homogeneous subduction-related component of constant composition and magnitude arises if the slab-derived flux migrates from the slab–mantle interface to the sub-arc melting column by repeated episodes of amphibole formation and decomposition its composition is then governed by the distribution coefficients of pyroxene and its magnitude by the degree of amphibole saturation of mantle peridotite. The results from Raoul Volcano are comparable to those from other oceanic subduction-related arcs such as South Sandwich and Marianas suggesting that this is a general model for oceanic arcs

    Laser-boosted lightcraft technology demonstrator

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    The detailed description and performance analysis of a 1.4 meter diameter Lightcraft Technology Demonstator (LTD) is presented. The launch system employs a 100 MW-class ground-based laser to transmit power directly to an advanced combined-cycle engine that propels the 120 kg LTD to orbit - with a mass ratio of two. The single-stage-to-orbit (SSTO) LTD machine then becomes an autonomous sensor satellite that can deliver precise, high quality information typical of today's large orbital platforms. The dominant motivation behind this study is to provide an example of how laser propulsion and its low launch costs can induce a comparable order-of-magnitude reduction in sensor satellite packaging costs. The issue is simply one of production technology for future, survivable SSTO aerospace vehicles that intimately share both laser propulsion engine and satellite functional hardware

    Investigations of the Low Temperature Combustion Regions and Emissions Characteristics of Aerospace F24 in a Constant Volume Combustion Chamber and a Common Rail Direct Injection Ci Engine

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    A study was conducted to investigate the low temperature combustion (LTC) regions of aerospace F24 and ULSD in the static setting of a CVCC and the dynamic setting of a CRDI research engine. This research is conducted to reduce in-cylinder emissions by understanding and implementing a technique to achieve an extended LTC. Emissions data for this study were collected during the operation of the CRDI research engine with a MKS 2030 FTIR and an AVL Microsoot 483. The parameters researched within the static setting of the CVCC included the determinations of the cool flames and NTC regions within the LTHR region. Investigations using the CRDI research engine included eight trials. These trials consisted of a baseline for each directly injected fuel, a trial with 0.24 bar of boosted intake air, a trial with 20% of recirculated exhaust gas, and finally a trial with PFI injections of a low reactivity bio-alcohol, n-butanol, during the intake stroke to cool the combustion chamber. PFI parameters also include additions of 0.24 bar of boost, 10% recirculated exhaust gas, and a pilot direct injection 60° BTDC. The low reactivity PFI fuel is utilized to facilitate an extended LTC. The CVCC results concluded with F24 and ULSD obtaining equal values for peak pressure and peak temperature, with the values of 42.3 bar and 1837.5 K, respectively. F24 maintained a longer period of cool flame formations and overall LTHR with values of 1.6ms and 1.96ms, respectively. The mass fraction burned results of ULSD within both the CVCC and dynamic setting of the CRDI research engine yielded better efficiency than F24 in nearly all trials. The trials implementing a LTC method within the CRDI research engine, was found to extend the low temperature combustion region of both F24 and ULSD. PFI trials reduced ignition delay by approx. 3 CAD and massively reduced soot emissions of ULSD and F24 by 9.9 and 2.5 times, respectively, compared to ULSD at baseline parameters. This reduction of soot was the greatest in-cylinder emissions reduction in the entire study. ULSD performed better overall in gaseous emissions outputs

    INVESTIGATIONS OF THE NEGATIVE TEMPERATURE COEFFICIENT REGION OF SUSTAINABLE AVIATION FUELS FOR MITIGATION OF GLOBAL WARMING

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    An investigation was led to determine the correlations between the durations of Ignition Delay (ID), Combustion Delay (CD), Derived Cetane Number (DCN), Negative Temperature Coefficient (NTC), Low-Temperature Heat Release (LTHR) regions, ringing intensity, and precent mass burn, and the effect of blending the Fischer-Tropsch (F-T) synthetic aerospace fuel (SAF), iso-paraffinic kerosene (IPK), with petroleum derived Jet-A aerospace fuel on these regions. Neat blends of Jet-A and IPK and three by mass blends of the fuels will be researched. These blends include mass percentages of 75%Jet-A and 25%IPK (75Jet-A25IPK), 50%Jet-A 50%IPK (50Jet-A50IPK), and 25%Jet-A 75%IPK (25Jet-A75IPK). The study will utilize a PAC CID 510 constant volume combustion chamber (CVCC) using the ASTM D7668-14.a standard. It was discovered that blends containing more by mass amounts of IPK had exponentially larger ID and CD, thus causing the DCN of the fuel blends to exponentially decrease. IPK also influenced the LTHR and NTC regions heavily as the fuel blends that contained larger amounts of IPK had a profound increase in the duration of both regions. Additionally, the blends that contained 50% or more by mass amounts of IPK had little to no ringing events occurring after HTHR, indicating a greater combustion stability. Finally, it was found that the energy released during the LTHR region of all the blended fuel’s burn was larger than that of the neat blends. This is due to IPK causing an extended LTHR region, while the Jet-A present in the fuel is releasing more energy during the extended LTHR duration

    The Impact of Vein Mechanical Compliance on Arteriovenous Fistula Outcomes

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    © 2016 Elsevier Inc. Background Arteriovenous fistulae (AVFs) are the preferred access for hemodialysis but suffer a high early failure rate. The aim of this study was to determine how venous distensibility, as measured in vitro, relates to early outcomes of AVF formed with the sampled vein. Methods Ethical approval was obtained for all aspects of this study. During AVF formation a circumferential segment of the target vein was sampled. Mechanical stress testing of the venous segments was undertaken using a dynamic mechanical analyzer, with progressive stress loading at 2 N/min to a maximum of 10 N or until sample disruption. Stress-strain curves were obtained for vein samples and Young's modulus (YM) calculated. Duplex assessment of the fistulae was undertaken at 30 days. Results Thirty patients consented to participate with 29 samples obtained for analysis. Statistical comparison of YM demonstrated no relationship with common cardiovascular risk factors or dialysis status. Subject age greater than 65 was the only patient factor which showed a significant difference in YM (P = 0.05). Furthermore, a negative correlation was confirmed between age and YM (Pearson's r = -0.465, P < 0.05). Nine of the 29 subjects suffered an early AVF failure. Mann-Whitney U testing for differences in distribution reported that YM was significantly higher in those fistulas which failed (P < 0.005). Conclusions Reduced venous compliance appears to result in higher failure rates of AVFs. With the advancement of clinical tools such as speckle tracing ultrasound identification of vessel compliance in vivo may produce valuable additional information for clinicians planning AVF surgery

    Taxation of forest land in South Missouri

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    This bulletin is a report on Department of Forestry Research Project 124, 'Timber Economics'--P. [2].Digitized 2007 AES.Includes bibliographical references (page 36)

    Marketing farm woodlot products in Franklin, Osage, and Gasconade counties

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    Caption title.Includes bibliographical references

    Alginate hydrogel has a negative impact on in vitro collagen 1 deposition by fibroblasts

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    Hydrogels have been widely investigated as 3D culture substrates because of their reported structural similarity to the extracellular matrix (ECM). Limited ECM deposition, however, occurs within these materials, so the resulting “tissues” bear little resemblance to those found in the body. Here matrix deposition by fibroblasts encapsulated within a calcium alginate (Ca-alg) hydrogel was investigated. Although the cells transcribed mRNA for coll Iα over a period of 3 weeks, very little collagen protein deposition was observed within the gel by histology or immunohistochemistry (IHC). Although molecular diffusion demonstrated charge dependency, this did not prevent the flux of both positively and negative charged amino acids through the gel, suggesting that the absence of ECM could not be attributed to substrate limitation. The flux of protein, however, was charge-dependent as proteins with a net negative charge passed quickly through the Ca-alg into the medium. The minimal collagen deposition within the Ca-alg was attributed to a combination of rapid movement of negatively charged procollagen through the gel and steric hindrance of fibril formation
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