Search results for " sample"
showing 10 items of 456 documents
Dog-bite-related attacks: A new forensic approach
2020
Dog attacks today represent a health hazard considering that prevention strategies have not always been successful. The identification of the dog that attacked the victim is necessary, considering the civil or criminal consequences for the animal's owner. An accurate scene analysis must be performed collecting a series of important information.Forensic investigations in dog attacks involve different methods, such as the evaluating of the canine Short Tandem Repeat (STR) typing in saliva traces on wounds or bite mark analysis, however, these techniques cannot always be applied. The effort to find new methods to identify the dog that attacked the victim represents a very interesting field for…
Revenue models, in-app purchase, and the app performance: Evidence from Apple's App Store and Google Play
2016
The effect of revenue models on app performance depends on the app store.The effect of in-app purchase on app performance depends on the app store.Paid, freemium and in-purchase models are shown to be effective in app store.Freemium and in-app purchase models are shown to be less effective in Google Play.App category influences the effects of both revenue models and in-app purchase. In this paper, we empirically examine how the revenue model (paid, free, or freemium) adopted for a given app affects the app revenue performance as measured by the app daily revenue rank. We also study the impact of in-app purchase on this measure of performance. Moreover, we study how such relationships are co…
Sample Preparation to Determine Pharmaceutical and Personal Care Products in an All-Water Matrix: Solid Phase Extraction
2020
© 2020 by the authors.
Automatic regrouping of strata in the goodness-of-fit chi-square test
2019
Pearson’s chi-square test is widely employed in social and health sciences to analyze categorical data and contingency tables. For the test to be valid, the sample size must be large enough to provide a minimum number of expected elements per category. This paper develops functions for regrouping strata automatically no matter where they are located, thus enabling the goodness-of-fit test to be performed within an iterative procedure. The functions are written in Excel VBA (Visual Basic for Applications) and in Mathematica. The usefulness and performance of these functions is illustrated by means of a simulation study and the application to different datasets. Finally, the iterative use of …
Utility of the Mantel-Haenszel Procedure for Detecting Differential Item Functioning in Small Samples
2004
Sample-size restrictions limit the contingency table approaches based on asymptotic distributions, such as the Mantel-Haenszel (MH) procedure, for detecting differential item functioning (DIF) in many practical applications. Within this framework, the present study investigated the power and Type I error performance of empirical and inferential criteria for DIF detection in small samples. Sample sizes (50/50, 100/50, 200/50, and 100/100 for the reference and focal groups, respectively), ability distributions (equal and unequal), and amount of DIF (moderate and high) were manipulated. The results show the advantages of employing theMHchi-square statistic using high levels of significance (•…
Planktonic foraminifera in ODP Hole 160-963A
2006
New faunal and floral records from Ocean Drilling Project Hole 963A, resolved at ?80-year spacing, provide evidence of suborbital scale climate variability in the central Mediterranean Sea throughout Marine Isotope Stage (MIS) 5. Cold events in the central Mediterranean Sea, indicated by low abundances of warm species and high abundances of cold species, are also evident in a planktonic foraminifera paleoclimatic curve. They have been linked to NGRIP Greenland ice core “C” events and appear correlative with similar sub-millennial climate fluctuations identified in the North Atlantic region and in the Alboran Basin (Westernmost Mediterranean). Low-resolution benthic and planktonic Oxygen Iso…
Long- and short-term in vitro D-dimer stability measured with INNOVANCE D-Dimer.
2009
Summary In vitro D-dimer stability in plasma is widely assumed, but has not yet been documented by systematic studies using samples covering a wide range of D-dimer. We investigated the short- and long-term stability of D-dimer in clinical citrated plasma samples with normal and pathological levels. The short-term stability was analysed by measuring D-dimer fresh, after storage of plasma for 4 hours at room temperature (RT) and after an additional 24 h storage at +2 to +8°C (n=40). Long-term stability samples (n=40) were measured fresh and after storage for 19, 25 and 36 months at ≤-60°C. The effect of repeated freezing was analysed by measuring samples (n=50) fresh and after four consecuti…
Supported liquid membrane extraction with single hollow fiber for the analysis of fluoroquinolones from environmental surface water samples
2010
Abstract In this work, the simple analytical method for the determination of four fluoroquinolone antibiotics: ciprofloxacin, enrofloxacin, norfloxacin and danofloxacin, in environmental surface water samples is described. Sample pretreatment step was performed by the application of a technique based on supported liquid membrane extraction with the configuration of single hollow fiber (HF-SLM). The HPLC system with diode array detection was used for final analysis of studied analytes. Various parameters affecting the extraction efficiency during HF-SLM enrichment, such as type of membrane diluent, pH of donor (sample) and acceptor phases, as well as an enrichment time and salt content of sa…
Osseointegration of miniscrews: a histomorphometric evaluation.
2007
SUMMARY Mini-implants and miniscrews are commonly used in orthodontics to provide additional temporary intraoral anchorage. Partial osseointegration represents a distinct advantage in orthodontic applications, allowing effective anchorage to be combined with easy insertion and removal. This article reports the histomorphometric fi ndings of the osseointegration of bracket screw bone anchors (BSBAs). In an experimental animal study, four BSBAs were inserted in the alveolar process of the lower jaw in each of fi ve male beagle dogs, aged 6.5 months from the same mother. Eleven screws were lost during the study, nine of them due to lack of primary stability. One screw was removed at the end of…
Familia, profesorado e iguales: claves para el apoyo a las víctimas de acoso escolar
2011
ResumenEl objetivo del presente estudio fue analizar las diferencias en ajuste psicológico en víctimas de acoso escolar en función de la calidad de sus relaciones con padres, profesores e iguales. En concreto, se compararon cuatro indicadores de ajuste psicológico (autoestima, ánimo depresivo, soledad y percepción de estrés) en víctimas con buena o mala comunicación con la madre, buena o mala comunicación con el padre, alta o baja percepción de ayuda del profesor, y alta o baja identificación con su grupo de iguales. La muestra inicial estuvo compuesta por 1795 adolescentes, entre 11 y 18 años (M=14.2, DT=1.68). Los resultados indicaron que las víctimas que mantenían mejores relaciones soci…