Search results for "ample"
showing 10 items of 2398 documents
The role of travel motivations and social media use in consumer interactive behaviour: a uses and gratifications perspective
2020
This paper explores the influence of travel motivations and the gratification provided by social media in consumer stickiness to social media, intention to create user-generated content, and electronic word of mouth (eWOM) review adoption. The study follows a mixed-methods approach. First, a concept mapping study was undertaken to identify the main travel motivations and the gratifications provided by social media when consumers search for information on tourism destinations. A second study using structural equation modelling and SmartPLS 3.2.7 with a sample of 401 heavy users of social media showed the relationships between individual travel motivations and gratifications provided by socia…
A novel approach for analysis of oligonucleotide-cisplatin interactions by continuous elution gel electrophoresis coupled to isotope dilution inducti…
2008
In this work we present a novel approach for in vitro studies of cisplatin interactions with 8-mer oligonucleotides. The approach is based on the recently developed coupling of continuous elution gel electrophoresis (GE) to an inductively coupled plasma-sector field mass spectrometer (ICP-SFMS) with the aim of monitoring the interaction process between this cytostatic drug and the nucleotides. In contrast to existing methods, the electrophoretic separation conditions used here allow both the determination of the reaction kinetics in more detail as well as the observation of dominant intermediates. Two different nucleotides sequences have been investigated for comparison purposes, one contai…
Method development of levoglucosenone analysis by UHPLC-UV-MS in fast pyrolysis samples and aspects of its degradation in aqueous samples
2020
Levoglucosenone ((1S,5R)-6,8-dioxabicyclo[3.2.1]oct-2-en-4-one or LGO; CAS number: 37112-31-5) is an extensively studied biomass based chemical and its potential applications in organic synthesis, as well as in the extraction of various natural substances, have been established; therefore developing dependable, yet fast and simple analytical methods for determining LGO in the products of thermochemical biomass processing is of great importance. In this work different UHPLC methods have been developed and compared for the determination of LGO in wood pyrolysis products. In addition to UV detection, LGO determination conditions by single quadrupole mass spectrometry have been adjusted with an…
Analysis of fumonisins B1, B2 and B3 in corn-based baby food by pressurized liquid extraction and liquid chromatography/tandem mass spectrometry
2008
A sensitive and reliable method using pressurized liquid extraction (PLE) and liquid chromatography (LC)/electrospray ionization (ESI) tandem mass spectrometry with a triple quadrupole (QqQ) analyzer has been developed for the analysis of fumonisin B(1) (FB(1)), fumonisin B(2) (FB(2)) and fumonisin B(3) (FB(3)) in corn-based baby foods. Influence of several extraction parameters that affect PLE efficiency such as temperature, pressure, solvent extraction, number of cycles and dispersant/clean-up agents were studied. The selected PLE operating method was: 3g of sample was packed into 11 ml stainless-steel cell and fumonisins were extracted with methanol at 40 degrees C, 34 atm in one cycle o…
Comparison of various liquid chromatographic methods for the analysis of avermectin residues in citrus fruits.
2001
Abstract Various liquid chromatographic (LC) techniques for analyzing avermectin (Abamectin) were compared after extraction of residues from citrus fruit samples by matrix solid-phase dispersion (MSPD). LC with UV and fluorescence detection were used as also was LC coupled to the mass spectrometer by an electrospray interface. The results obtained by the three methods were compared in terms of sensitivity and selectivity. The combination of MSPD extraction and LC with fluorescence detection have made it possible to quantify 0.5 μg kg −1 of Abamectin in 0.5 g of orange sample, with an overall average recovery of 94%. The procedure provides a simple and sensitive method for monitoring Abamect…
Analysis of meat samples for anabolic steroids residues by liquid chromatography/tandem mass spectrometry.
2007
A rapid, specific and highly sensitive multi-residue method for the determination of anabolic steroid residues in bovine, pork and poultry muscle tissues was developed. The sample preparation involves enzymatic digestion followed by extraction with methanol. The crude extract was cleaned up by solid-phase extraction (SPE) combining C18 and NH2 columns. The detection was carried out by a highly sensitive liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) method using both positive and negative ionization modes. Natural and synthetic steroids covering different polarities could be extracted, concentrated and purified using one single method. Mobile phase com…
Representative major element compositions of clinopyroxenes and phlogopites from ultrapotassic rocks from Nangqian basin (Eastern Tibet)
2020
Representative major element compositions (in wt%) of clinopyroxenes and phlogopites from Nangqian ultrapotassic rocks. In-situ major-element compositions of mineral phases were obtained using the JEOL JXA-8230 Electron Microprobe at ISTerre, University Grenoble Alpes. Analytical conditions were 15 kV accelerating voltage and 12 nA beam current. The ZAF procedure was applied to reduce the raw data. The microprobe was calibrated using natural and synthetic standards. An X-ray element map of a calcite-bearing aggregate was acquired using 15 kV accelerating voltage and 10 nA beam current.
The Italian adaptation and validation of the Adult Sibling Relationship Questionnaire (ASRQ) in Italian emerging adults
2013
The aims of the present study were to provide a contribution to the validation of the Adult Sibling Relationship Questionnaire (ASRQ) (Stocker, Lanthier, & Furman, 1997) with a population of Italian emerging adults. The ASRQ measures individuals’ current perceptions of their own behaviour and feelings toward their sibling, as well as their perceptions of their sibling’s behaviour and feelings toward him or her by assessing fourteen fundamental dimensions (Intimacy; Affection; Emotional Support; Instrumental Support; Knowledge; Similarity; Admiration; Acceptance; Dominance; Competition; Antagonism; Quarrelling; Maternal Rivalry; and Paternal Rivalry), combined in order to form three macro-di…
Sharing economy and dynamic pricing: Is the impact of Airbnb on the hotel industry time-dependent?
2021
Abstract Prior literature has reported significant price and revenue reductions in the hotel industry due to the emergence of Airbnb. Other studies have documented that hotels' price reactions to the penetration of Airbnb depend on their service level, e.g., low/medium-end versus high end. Relying on a large sample from the Italian market, we contribute by showing that the effect of Airbnb on hotels' price decisions does not only depend on incumbents’ quality level, but also on the difference between booking and check-in time. That is, the effect of the penetration of Airbnb on hotels' dynamic price decisions varies over time depending on the core segment hotels target.
Liberal and Conservative Differential Item Functioning Detection Using Mantel-Haenszel and SIBTEST: Implications for Type I and Type II Error Rates
2004
The aim of this work was to determine, in terms of Type I and Type II error rates, the risks of applying various statistical procedures for evaluating differential item functioning. To this end, the authors carried out a simulation study in which the Mantel-Haenszel and SIBTEST procedures were applied in conjunction. The variables manipulated were sample size and distribution of ability between groups. Results indicated that, although there was a high rate of agreement between the procedures, the joint Type I and Type II error rate may vary substantially from that obtained when each of the procedures was applied separately. Furthermore, the authors analyzed empirical data to obtain informat…