Search results for "ample"
showing 10 items of 2398 documents
Accuracy of ASTER Level-2 thermal-infrared Standard Products of an agricultural area in Spain
2007
Abstract The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) collects five-channel thermal-infrared images that are calibrated, corrected for atmospheric effects, and then converted to land surface temperature and emissivity products by the ASTER Temperature/Emissivity Separation (TES) algorithm. TES scales low- and high-contrast surfaces differently, and has been validated over water (low contrast) and rock (high contrast). Performance of TES over agricultural areas, however, has not been evaluated specifically. To address this issue, field measurements of “ground truth” were made over bare soil in addition to green grass, alfalfa and corn, at an agricultural researc…
Design Issues and Sample Size when Exposure Measurement is Inaccurate
2001
AbstractMeasurement error often leads to biased estimates and incorrect tests in epidemiological studies. These problems can be corrected by design modifications which allow for refined statistical models, or in some situations by adjusted sample sizes to compensate a power reduction. The design options are mainly an additional replication or internal validation study. Sample size calculations for these designs are more complex, since usually there is no unique design solution to obtain a prespecified power. Thus, additionally to a power requirement, an optimal design should also fulfill the criteria of minimizing overall costs. In this review corresponding strategies and formulae are descr…
Drop-on-demand sample introduction system coupled with the flowing atmospheric-pressure afterglow for direct molecular analysis of complex liquid mic…
2012
One of the fastest developing fields in analytical spectrochemistry in recent years is ambient desorption/ionization mass spectrometry (ADI-MS). This burgeoning interest has been due to the demonstrated advantages of the method: simple mass spectra, little or no sample preparation, and applicability to samples in the solid, liquid, or gaseous state. One such ADI-MS source, the flowing atmospheric-pressure afterglow (FAPA), is capable of direct analysis of solids just by aiming the source at the solid surface and sampling the produced ions into a mass spectrometer. However, direct introduction of significant volumes of liquid samples into this source has not been possible, as solvent loads c…
Gel Electrophoresis Coupled to Inductively Coupled Plasma−Mass Spectrometry Using Species-Specific Isotope Dilution for Iodide and Iodate Determinati…
2007
In this paper, we present an online coupling of gel electrophoresis (GE) and inductively coupled plasma-mass spectrometry (ICP-MS) for the determination of iodine species (iodide and iodate) in liquid (seawater) and aerosol samples. For the first time, this approach is applied to the analysis of small molecules, and initial systematic investigations revealed that the migration behavior as well as the detection sensitivity strongly depends on the matrix (e.g., high concentrations of chloride). These effects could consequently affect the accuracy of analytical results, so that they need to be considered for the analysis of real samples. The technique used for quantification is species-specifi…
Affective temperaments in tango dancers.
2015
Background: Links between affective temperaments and folk culture have been infrequently explored systematically. Creativity and personality and temperament studies, conversely, have reported several associations. Tango is one of the most typical Argentinean folk dance-musical repertoires. The main purpose of this study is to compare affective temperaments between Argentinean professional tango dancers and the general population. Methods: TEMPS-A was administered to a sample of 63 professional tango dancers and 63 comparison subjects from the general population who did not practice tango. Subscale median scores and total median scores with non-parametric statistics were analyzed. Results: M…
Determination of aflatoxins in peanuts by matrix solid-phase dispersion and liquid chromatography
2003
A new method based on matrix solid-phase dispersion (MSPD) extraction was studied to determine aflatoxin B1, B2, G1 and G2 from peanuts. Optimization of different parameters, such as type of solid supports for matrix dispersion and elution solvents were carried out. The method used 2 g of peanut sample, 2 g of C18 bonded silica as MSPD sorbent and acetonitrile as eluting solvent. Recoveries of each aflatoxin spiked to peanut samples at 2.5 ng/g (5 ng/g for aflatoxin G2) level were between 78 and 86% with relative standard deviations ranging from 4 to 7%. The limits of quantification ranged from 0.125 to 2.5 ng/g for the four studied aflatoxins using liquid chromatography (LC) with fluoresce…
Occurrence of aflatoxins in feedstuff, sheep milk and dairy products in Western Sicily
2003
Samples of feedstuffs (15), milk (40), and cheese (30) coming from sheep and dairy farms (23) or market in WesternSicily were analyzed for their respective content of aflatoxin B1 (AFB1) and M1 (AFM1) to evidence any possible indirectmycotoxin contamination risk to the consumer. Analyses using HPLC and fluorescence detection were performed afterimmunoaffinity column sample extraction and cleanup; AFM1 was detected in 30% of the milk samples at levels rangingfrom 4 to 23 ng/l and in 13% of the cheeses from 21 to 101 ng/kg; in the feed the AFB1 ranged from None of the contaminated samples exceeded the legal limits set down by the European Union for milk (50 ng/l) and feed(5 μg/kg ), or tha…
MYCOTOXINS | Detection and Analysis by Classical Techniques
2014
This article is a revision of the previous edition article by Imad Ali Ahmed, volume 2, pp. 1526–1532, © 1999, Elsevier Ltd.
Cyberbullying: diferencias en función del sexo y curso académico
2019
El cyberbullying es un problema grave y transcultural. Los estudios por lo que se refiere a la diferencia en cuanto al género y la edad de víctimas y agresores son inconsistentes. En este contexto, los objetivos del presente estudio fueron analizar si existen diferencias en la cibervictimización y ciberagresión en función del sexo (chicos y chicas), y el curso académico (1º, 2º, 3º, y 4º de la ESO). Participaron 660 adolescentes pertenecientes a cuatro institutos públicos de edades comprendidas entre los 12 y los 18 años. Los resultados muestran que no existen diferencias significativas entre chicos y chicas ni en la cibervictimización, ni en la ciberagresión. Respecto al curso académico, n…
Jerarquización y preferencia de valores en los estudiantes de secundaria = Hierarchial structuring and preference of values in the students of second…
2014
This article describes a study of the values and variables that influence hierarchical structuring in secondary school students. The main objectives are to determine which are the preferred values and to compare in what manner gender and age are related to the values of adolescents. The study is conducted with a sample (n=114) of male and female secondary school students, between 14 and 18 years old. The results show that the two variables (gender and age) are related to the subject’s values. Girls prefer final values, more abstract and internalized values; opposite to the instrumental, more egocentric and material values, preferred by boys. Regarding age influence, as they grow older, adol…