908 research outputs found
Simulation of pesticide concentrations in groundwater using Agricultural Drainage and Pesticide Transport (ADAPT) model
A water quality model for subirrigation and subsurface drainage, ADAPT (Agricultural Drainage And Pesticide Transport), was tested with field data collected under various water table management practices near Ames, IA. Atrazine and alachlor concentrations at various soil depths for water table depths of 30, 60, and 90 cm were simulated using ADAPT model for corn growing seasons of 1989 through 1991. Daily pesticide concentrations in groundwater predicted by the model were compared with available observed data for the same site. Predicted values of atrazine and alachlor concentrations in groundwater decreased when shallow water table depths were maintained in the lysimeters. Similar trends were noticed with the observed data. Reasonable agreement was obtained between the observed and predicted values of atrazine and alachlor for 1989 to 1991. However, in few cases, results showed a wide variation between observed and predicted values. Because no observed data was available for pesticide concentrations in the unsaturated zone, predicted results could not be compared. Based on our investigation, it appears that ADAPT may be used for predicting subsurface water quality under water table management practices; however, further validation is necessary with more field observed data from similar studies before wider application of this model is made
An examination of the association between seeing smoking in films and tobacco use in young adults in the west of Scotland: cross-sectional study
The objective is to examine the association between the amount of smoking seen in films and current smoking in young adults living in the west of Scotland in the UK. Cross-sectional analyses (using multivariable logistic regression) of data collected at age 19 (2002ā04) from a longitudinal cohort originally surveyed at age 11 (1994ā95) were conducted. The main outcome measure is smoking at age 19. No association was found between the number of occurrences of smoking estimated to have been seen in films (film smoking exposure) and current (or ever) smoking in young adults. This lack of association was unaffected by adjustment for predictors of smoking, including education, risk-taking orientation and smoking among peers. There was no association between film smoking exposure and smoking behaviour for any covariate-defined subgroup. Associations have been found between film smoking exposure and smoking initiation in younger adolescents in the United States. In this study, conducted in Scotland, no similar association was seen, suggesting that there may be age or cultural limitations on the effects of film smoking exposure on smoking. The lack of association could be due to methodological issues or greater sophistication of older adolescents and young adults in interpreting media images or the greater ubiquity of real-life smoking instances in Scotland. If the latter, film smoking exposure could become a more important risk factor for smoking uptake and maintenants in older adolescents following the recent ban on smoking in public places in Scotland
Terrace channel design using the spatially varied flow and tractive force theories
Digitized 2007 AES.Includes bibliographical references (pages 31-32)
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Global Gene Expression Analysis Identifies Age-Related Differences in Knee Joint Transcriptome during the Development of Post-Traumatic Osteoarthritis in Mice.
Aging and injury are two major risk factors for osteoarthritis (OA). Yet, very little is known about how aging and injury interact and contribute to OA pathogenesis. In the present study, we examined age- and injury-related molecular changes in mouse knee joints that could contribute to OA. Using RNA-seq, first we profiled the knee joint transcriptome of 10-week-old, 62-week-old, and 95-week-old mice and found that the expression of several inflammatory-response related genes increased as a result of aging, whereas the expression of several genes involved in cartilage metabolism decreased with age. To determine how aging impacts post-traumatic arthritis (PTOA) development, the right knee joints of 10-week-old and 62-week-old mice were injured using a non-invasive tibial compression injury model and injury-induced structural and molecular changes were assessed. At six-week post-injury, 62-week-old mice displayed significantly more cartilage degeneration and osteophyte formation compared with young mice. Although both age groups elicited similar transcriptional responses to injury, 62-week-old mice had higher activation of inflammatory cytokines than 10-week-old mice, whereas cartilage/bone metabolism genes had higher expression in 10-week-old mice, suggesting that the differential expression of these genes might contribute to the differences in PTOA severity observed between these age groups
Intersected EMG heatmaps and deep learning based gesture recognition
Hand gesture recognition in myoelectric based prosthetic devices is a key challenge to offering effective solutions to hand/lower arm amputees. A novel hand gesture recognition methodology that employs the difference of EMG energy heatmaps as the input of a specific designed deep learning neural network is presented. Experimental results using data from real amputees indicate that the proposed design achieves 94.31% as average accuracy with best accuracy rate of 98.96%. A comparison of experimental results between the proposed novel hand gesture recognition methodology and other similar approaches indicates the superior effectiveness of the new design
Static Friction between Elastic Solids due to Random Asperities
Several workers have established that the Larkin domains for two three
dimensional nonmetallic elastic solids in contact with each other at a
disordered interface are enormously large. This implies that there should be
negligible static friction per unit area in the macroscopic solid limit.
The present work argues that the fluctuations in the heights of the random
asperities at the interface that occur in the Greenwood-Williamson model can
account for static friction.Comment: Contains some improvements in the treatment of the subjec
A well-separated pairs decomposition algorithm for k-d trees implemented on multi-core architectures
Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.Variations of k-d trees represent a fundamental data structure used in Computational Geometry with numerous applications in science. For example particle track tting in the software of the LHC experiments, and in simulations of N-body systems in the study of dynamics of interacting galaxies, particle beam physics, and molecular dynamics in biochemistry. The many-body tree methods devised by Barnes and Hutt in the 1980s and the Fast Multipole Method introduced in 1987 by Greengard and Rokhlin use variants of k-d trees to reduce the computation time upper bounds to O(n log n) and even O(n) from O(n2). We present an algorithm that uses the principle of well-separated pairs decomposition to always produce compressed trees in O(n log n) work. We present and evaluate parallel implementations for the algorithm that can take advantage of multi-core architectures.The Science and Technology Facilities Council, UK
Extracardiac 18F-florbetapir imaging in patients with systemic amyloidosis: more than hearts and minds
PURPOSE: 18F-Florbetapir has been reported to show cardiac uptake in patients with systemic light-chain amyloidosis (AL). This study systematically assessed uptake of 18F-florbetapir in patients with proven systemic amyloidosis at sites outside the heart. METHODS: Seventeen patients with proven cardiac amyloidosis underwent 18F-florbetapir PET/CT imaging, 15 with AL and 2 with transthyretin amyloidosis (ATTR). Three patients had repeat scans. All patients had protocolized assessment at the UK National Amyloidosis Centre including imaging with 123I-serum amyloid P component (SAP). 18F-Florbetapir images were assessed for areas of increased tracer accumulation and time-uptake curves in terms of standardized uptake values (SUVmean) were produced. RESULTS: All 17 patients showed 18F-florbetapir uptake at one or more extracardiac sites. Uptake was seen in the spleen in 6 patients (35%; 6 of 9, 67%, with splenic involvement on 123I-SAP scintigraphy), in the fat in 11 (65%), in the tongue in 8 (47%), in the parotids in 8 (47%), in the masticatory muscles in 7 (41%), in the lungs in 3 (18%), and in the kidney in 2 (12%) on the late half-body images.Ā The 18F-florbetapir spleen retention index (SRI) was calculated. SRI >0.045 had 100% sensitivity/sensitivity (in relation to 123I-SAP splenic uptake, the current standard) in detecting splenic amyloid on dynamic imaging and a sensitivity of 66.7% and a specificity of 100% on the late half-body images. Intense lung uptake was seen in three patients, one of whom had lung interstitial infiltration suggestive of amyloid deposition on previous high-resolution CT. Repeat imaging showed a stable appearance in all three patients suggesting no early impact of treatment response. CONCLUSION: 18F-Florbetapir PET/CT is a promising tool for the detection of extracardiac sites of amyloid deposition. The combination of uptake in the heart and uptake in the spleen on 18F-florbetapir PET/CT, a hallmark of AL, suggests that this tracer holds promise as a screening tool for AL
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