Search results for " Sampling"
showing 10 items of 375 documents
SENSORY EVALUATION AND SUITABILITY FOR FRESH-CUT PRODUCE OF WHITE PEACH [PRUNUS PERSICA (L.) BATSCH] 'SETTEMBRINA DI BIVONA'
2015
âSettembrina di Bivonaâ peaches were cut into slices to assess their suitability as fresh-cut produce. Untreated (control) and treated with calcium lactate fresh cut slices were closed in plastic boxes for 24 hours (T1) or five days of storage (T2) at 5°C, and then placed at 20°C to assess consumersâ liking. Soluble solids content, titratable acidity, firmness and pH were measured. A sample of n = 750 consumers was selected taking into consideration three variables: age (from 25 to 55 years old), professional status (employed) and aptitude to buy fresh-cut fruit for personal use. A systematic sampling was used, with a detection point based in a properly selected supermarket during t…
Caries prevalence in children from Valencia (Spain) using ICDAS II criteria, 2010
2014
Objectives: To assess the oral health status of the child population and its evolution over the 2004-2010 period. Study Design: A descriptive cross-sectional study of the entire schoolchild population of the Valencia region of Spain was conducted using cluster sampling. Seventy schools were selected. The sample size was 1373 pupils, aged 6, 12 and 15 years. The children were examined in November and December 2010, at their schools, by 6 examiners calibrated in the ICDAS II method. The descriptive statistics, comparison of means and comparison of proportions (p0) was 30% in primary dentition at 6 years and 37.7% and 43.6% in permanent dentition at 12 and 15 years respectively. At 6, 12 and 1…
Effects of alertness management training on sleepiness among long-haul truck drivers : a randomized controlled trial
2018
Education is a frequently recommended remedy for driver sleepiness in occupational settings, although not many studies have examined its usefulness. To date, there are no previous on-road randomized controlled trials investigating the benefits of training on sleepiness among employees working in road transport. To examine the effects of an educational intervention on long-haul truck drivers' sleepiness at the wheel, amount of sleep between work shifts, and use of efficient sleepiness countermeasures (SCM) in association with night and non-night shift, a total of 53 truck drivers operating from southern Finland were allocated into an intervention and a control group using a stratified random…
Predicting the bioaccumulation of polyaromatic hydrocarbons and polychlorinated biphenyls in benthic animals in sediments
2016
There were two main objectives in this study. The first was to compare the accuracy of different prediction methods for the chemical concentrations of polyaromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in the organism, based on the measured chemical concentrations existing in sediment dry matter or pore water. The predicted tissue concentrations were compared to the measured ones after 28-day laboratory test using oligochaeta worms (Lumbriculus variegatus). The second objective was to compare the bioaccumulation of PAHs and PCBs in the laboratory test with the in situ bioaccumulation of these compounds. Using the traditional organic carbon-water partitioning model, tissue…
Biodeterioration
2022
The biodeterioration of organic and inorganic materials, as well as polymers, is a complex of alteration processes induced by the growing and metabolic activity of organisms. It can be recognized on monuments, wall paintings, stone, wood, paper, vegetal/animal fibers, and parchment artworks. As defined by Hueck, 1968, biodeterioration is “any undesirable change in the properties of a material caused by the vital activities of organisms”; this definition is accepted as the meaning of the phenomenon. Both macroorganisms (such as animals, plants, and mosses) and microorganisms (such as autotrophic or heterotrophic bacteria, microfungi, cyanobacteria, algae, and lichens) represent the triggers …
Biopsy vs. brushing: comparison of two sampling methods for the detection of HPV-DNA in squamous cell carcinoma of the oral cavity
2012
Background: HR HPV infection was proposed as aetiological factor of oral squamous cell carcinomas (OSCC). HPV frequency in OSCC is highly variable, due to the discrepancy in oral sampling procedures, HPV testing methods and inclusion criteria regarding tumour site (strictly oral cavity vs. nearby structures). Our aim was to compare HPV DNA frequency and type-specific distribution in paired cytological and histological samples of SCC strictly located in oral cavity. The correlation between HPV detection rate by each method of sampling and demographical, behavioural and clinical-pathological variables was also examined. Patients and methods: HPV DNA was detected in brushed cells and formalin-…
The Tax Justice Network-Africa v Cabinet Secretary for National Treasury & 2 Others: A Big Win for Tax Justice Activism?
2019
This paper develops an optimization model for selecting a large subsample that improves the representativeness of a simple random sample previously obtained from a population larger than the population of interest. The problem formulation involves convex mixed-integer nonlinear programming (convex MINLP) and is therefore NP-hard. However, the solution is found by maximizing the “constant of proportionality” – in other words, maximizing the size of the subsample taken from a stratified random sample with proportional allocation – and restricting it to a p-value high enough to achieve a good fit to the population of interest using Pearson’s chi-square goodness-of-fit test. The beauty of the m…
On the stability and ergodicity of adaptive scaling Metropolis algorithms
2011
The stability and ergodicity properties of two adaptive random walk Metropolis algorithms are considered. The both algorithms adjust the scaling of the proposal distribution continuously based on the observed acceptance probability. Unlike the previously proposed forms of the algorithms, the adapted scaling parameter is not constrained within a predefined compact interval. The first algorithm is based on scale adaptation only, while the second one incorporates also covariance adaptation. A strong law of large numbers is shown to hold assuming that the target density is smooth enough and has either compact support or super-exponentially decaying tails.
Attitudes and perceptions of faculty members in the process adopting innovation: The OpenCourseWare initiative at the University of Valencia, Spain
2014
The OpenCourseWare project, an open learning resource repository, was established at the University of Valencia between 2008 and2009. It initially consisted of only 10 subjects, none of which was in the field of Health Sciences. The objective of this research was toinvestigate the attitudes and perceptions of faculty members in the field of Health Sciences with regard to the project to identify strategies to increase its use and expand its coverage. We applied Rogers’ innovation-diffusion theory along with a qualitative approach using theoretical sampling, semi-structured interviews and open coding. The results indicate the existence of two categories of faculty members. In the first group,…
Confidence bands for Horvitz-Thompson estimators using sampled noisy functional data
2013
When collections of functional data are too large to be exhaustively observed, survey sampling techniques provide an effective way to estimate global quantities such as the population mean function. Assuming functional data are collected from a finite population according to a probabilistic sampling scheme, with the measurements being discrete in time and noisy, we propose to first smooth the sampled trajectories with local polynomials and then estimate the mean function with a Horvitz-Thompson estimator. Under mild conditions on the population size, observation times, regularity of the trajectories, sampling scheme, and smoothing bandwidth, we prove a Central Limit theorem in the space of …