Search results for "SAMPLE"
showing 10 items of 2270 documents
Can Applications Designed to Evaluate Visual Function Be Used in Different iPads?
2018
SIGNIFICANCE: Apple devices could be suitable for vision tests, provided that the test has been correctly adapted to the device, after considering the spatial and colorimetric characterization of the screen. PURPOSE: The majority of vision applications has not been developed by vision or colorimetry experts and suffers from conceptual and design errors that may lead average users to an erroneous assessment of their visual capabilities. The reliability of vision tests depends on the accurate generation of the necessary visual stimuli in a particular device. Our aim was to ascertain whether a given color test, designed for a colorimetrically characterized device, might be used in another simi…
A Probabilistic Classification Procedure Based on Response Time Analysis Towards a Quick Pre-Diagnosis of Student's Attention Deficit
2019
[EN] A classification methodology based on an experimental study is proposed towards a fast pre-diagnosis of attention deficit. Our sample consisted of school-aged children between 8 and 12 years from Valencia, Spain. The study was based on the response time (RT) to visual stimuli in computerized tasks. The process of answering consecutive questions usually follows an ex-Gaussian distribution of the RTs. Specifically, we seek to propose a simple automatic classification scheme of children based on the most recent evidence of the relationship between RTs and ADHD. Specifically, the prevalence percentage and reported evidence for RTs in relation to ADHD or to attention deficit symptoms were t…
Attempt to Construct a Scale for the Measurement of the Effect of Suggestion on Perception1
1975
A scale based on experimental methods has been prepared for measuring the effects of indirect suggestion upon perception. Three categories are included: (1) distorting the interpretation of presented stimuli, (2) inducing sense-impressions in the absence of adequate stimuli, and (3) producing insensitivity to stimuli that are objectively present. Test situations were designed for tactual, auditory, and visual perception. The scale was tested on a sample of 112 students from the 11th and 12th grades of a large city high school (58 girls and 54 boys). Most of the item intercorrelations were positive and many significantly so. Eliminating the 9 lowest items of 21 left 12 for a reduced matrix,…
Intraoperative alteration of the total clearance of ascorbic acid in plasma
2003
Ascorbic acid (AA) is an important antioxidant in the plasma and has the tendency to postoperatively reduced values. This could be caused by an increased antioxidative activity of AA as a radical scavenger since operations are a well-known scenario of oxidative stress with increased radical production. There is some evidence for an intraoperative onset of oxidative stress which could be related to an increased antioxidative activity of AA. Therefore, the total clearance (Cltot) of AA was calculated pre- and intraoperatively in 20 neurosurgical patients. At both times plasma samples were taken before, and 15, 30, 60 and 120 minutes after an iv. AA-bolus of 4 mg/kg AA/body weight. Cltot of AA…
A new FESEM procedure for assessment of XRD microstructural data of kaolinites
2007
Abstract A sample preparation method for FESEM microstructural analysis of sheet silicates using oriented aggregates on metallic strips parallel to the electronic beam is described. The method allows the easy measurement of thickness of kaolinite crystallites. The results have been compared to the apparent crystallite size measured by XRD The performed measurements for a set of selected kaolinites are in the range 15–60 nm and show a good correlation with XRD crystallite thickness (in the range 11–48 nm) obtained by the Voigt function method.
Comparison of distance covered in paddle in the serve team according to performance level
2013
Although paddle is the second most practiced sport in Spain, the scientific knowledge about the players' work-load is still very low. The serve is a critical situation because the team has the opportunity to start the point attacking by approaching the net straight after the serve. However, the distance covered by the serve team still has not been studied in padel. OBJECTIVE: This study aimed to analyse the distance covered by the serve team according performance level. It was hypothesized that the server would cover more distance than his partner due to the approach to the net after the serve. Moreover, it also was hypothesized that the difference between serve and partner would be greater…
Plant Productivity Dispersion and the College Premium: Evidence from the United States 1977-1997
2015
For the United States in 1987-2014, I document at business cycle frequencies that the high-skill workers’ employer size wage premium is high (low) in times of low (high) unemployment relative to that of the low-skill workers. Specifically, the differential employer size wage premium between high-skill and low-skill workers has an unconditional correlation of -0.4 with the unemployment rate, and varies by about 6 percent over the business cycle. The skill premium itself does not exhibit a clear business cycle pattern over the sample period.
Bleach interference in forensic luminol tests on porous surfaces: more about the drying time effect.
2009
As criminals try to avoid leaving clues at the scene of a crime, bloodstains are often washed away, but fortunately for investigators, they are difficult to eliminate completely. Porous surfaces easily retain blood traces, which are sometimes invisible to the naked eye. The reagent of choice for detecting latent blood traces on all types of surfaces is luminol, but its main disadvantage is a high degree of sensitivity to oxidising contaminants in the blood sample. If household bleach is used to clean bloodstains, presumptive tests are invalidated. Hypochlorites, however, are known to be unstable and deteriorate over time, and this feature could be of help in preventing household bleach-indu…
Absorption characteristics, major elements and chl a content of samples from Pond 19 at Zackenberg, NE Greenland
2012
1. Shallow arctic lakes and ponds have simple and short food webs, but large uncertainties remain about benthic-pelagic links in these systems. We tested whether organic matter of benthic origin supports zooplankton biomass in a pond in NE Greenland, using stable isotope analysis of carbon and nitrogen in the pond itself and in a 13C-enrichment enclosure experiment. In the latter, we manipulated the carbon isotope signature of benthic algae to enhance its isotopic discrimination from other potential food sources for zooplankton. 2. The cladoceran Daphnia middendorffiana responded to the 13C-enrichment of benthic mats with progressively increasing d13C values, suggesting benthic feeding. Sta…
Gully Erosion Susceptibility Mapping Using Multivariate Adaptive Regression Splines—Replications and Sample Size Scenarios
2019
Soil erosion is a serious problem affecting numerous countries, especially, gully erosion. In the current research, GIS techniques and MARS (Multivariate Adaptive Regression Splines) algorithm were considered to evaluate gully erosion susceptibility mapping among others. The study was conducted in a specific section of the Gorganroud Watershed in Golestan Province (Northern Iran), covering 2142.64 km2 which is intensely influenced by gully erosion. First, Google Earth images, field surveys, and national reports were used to provide a gully-hedcut evaluation map consisting of 307 gully-hedcut points. Eighteen gully erosion conditioning factors including significant geoenvironmental and morph…