Evaluación de propiedades psicométricas para identificar trastornos por ingesta de alcohol en una universidad de Chimborazo / Evaluation of psychometric properties to identify alcohol intake disorders at a university in Chimborazo

INTRODUCCIÓN. El alcohol es la sustancia psicoactiva con más alto índice de con-sumo a nivel mundial, una de las formas de evaluación de esta problemática es por medio del Alcohol Use Disorders Identification Test. OBJETIVO. Evaluar las pro-piedades psicométricas del cuestionario en una universidad de Chimborazo. MATE-RIALES Y MÉTODOS. Estudio observacional, prospectivo, con una población de 2 064 adultos jóvenes, y muestra de 978 universitarios. El muestreo aplicado fue no probabilístico intencional, en la Universidad Nacional de Chimborazo, periodo abril a diciembre del año 2018. Se realizó análisis de confiabilidad y de validez del Alcohol Use Disorders Identification Test de la Organización Mundial de la Salud por medio del método Delphi. RESULTADOS. La investigación se desarrolló con una muestra no clínica, el 72,8% (712; 978) correspondió a género femenino; las edades com-prendidas entre 18 y 34 años con una X= 21,16. La confiabilidad se aplicó el patrón de referencia del análisis de fiabilidad y validez el α=0,831. Un análisis factorial con-firmatorio de la prueba Kaiser, Meyer y Olkin y prueba de Bartlett= 0,898 y una signifi-cación de p= 0,00. CONCLUSIÓN. Los resultados psicométricos permitieron concluir que el instrumento fue válido y confiable para evaluar consumo perjudicial de alcohol en un contexto propio universitario.

INTRODUCTION. Alcohol is the psychoactive substance with the highest rate of consumption worldwide, one of the forms of evaluation of this problem is through the Alcohol Use Disorders Identification Test. OBJECTIVE. To evaluate the psycho-metric properties of the questionnaire at a University in Chimborazo. MATERIALS AND METHODS. Observational, prospective study, with a population of 2 064 young adults, and a sample of 978 university students. The sampling applied was intentional non-probabilistic, at the National University of Chimborazo, period april to december 2018. Reliability and validity analyses of the World Health Organization's Alcohol Use Disorders Identification Test were performed using the Delphi method. RESULTS. The research was developed with a non-clinical sample, 72,8% (712; 978) corres-ponded to female; ages between 18 and 34 years old with an X= 21,16. Confidence was applied to the reference pattern of the reliability and validity analysis of α=0,831. A confirmatory factorial analysis of the Kaiser, Meyer and Olkin test and Bartlett test= 0,898 and a significance of p=0,00. CONCLUSION. The psychometric results allow us to conclude that the instrument is valid and reliable to evaluate harmful alcohol consumption in its own university context.

Classification of Coffee Beans by GC-C-IRMS, GC-MS, and (1)H-NMR.

In a previous work using (1)H-NMR we reported encouraging steps towards the construction of a robust expert system for the discrimination of coffees from Colombia versus nearby countries (Brazil and Peru), to assist the recent protected geographical indication granted to Colombian coffee in 2007. This system relies on fingerprints acquired on a 400 MHz magnet and is thus well suited for small scale random screening of samples obtained at resellers or coffee shops. However, this approach cannot easily be implemented at harbour's installations, due to the elevated operational costs of cryogenic magnets. This limitation implies shipping the samples to the NMR laboratory, making the overall approach slower and thereby more expensive and less attractive for large scale screening at harbours. In this work, we report on our attempt to obtain comparable classification results using alternative techniques that have been reported promising as an alternative to NMR: GC-MS and GC-C-IRMS. Although statistically significant information could be obtained by all three methods, the results show that the quality of the classifiers depends mainly on the number of variables included in the analysis; hence NMR provides an advantage since more molecules are detected to obtain a model with better predictions.

Combining Internet monitoring processes, packaging and isotopic analyses to determine the market structure: example of Gamma Butyrolactone.

The Internet is becoming more and more popular among drug users. The use of websites and forums to obtain illicit drugs and relevant information about the means of consumption is a growing phenomenon mainly for new synthetic drugs. Gamma Butyrolactone (GBL), a chemical precursor of Gamma Hydroxy Butyric acid (GHB), is used as a "club drug" and also in drug facilitated sexual assaults. Its market takes place mainly on the Internet through online websites but the structure of the market remains unknown. This research aims to combine digital, physical and chemical information to help understand the distribution routes and the structure of the GBL market. Based on an Internet monitoring process, thirty-nine websites selling GBL, mainly in the Netherlands, were detected between January 2010 and December 2011. Seventeen websites were categorized into six groups based on digital traces (e.g. IP addresses and contact information). In parallel, twenty-five bulk GBL specimens were purchased from sixteen websites for packaging comparisons and carbon isotopic measurements. Packaging information showed a high correlation with digital data confirming the links previously established whereas chemical information revealed undetected links and provided complementary information. Indeed, while digital and packaging data give relevant information about the retailers, the supply routes and the distribution close to the consumer, the carbon isotopic data provides upstream information about the production level and in particular the synthesis pathways and the chemical precursors. A three-level structured market has been thereby identified with a production level mainly located in China and in Germany, an online distribution level mainly hosted in the Netherlands and the customers who order on the Internet.

On the use of IRMS in forensic science: proposals for a methodological approach.

The flourishing number of publications on the use of isotope ratio mass spectrometry (IRMS) in forensic science denotes the enthusiasm and the attraction generated by this technology. IRMS has demonstrated its potential to distinguish chemically identical compounds coming from different sources. Despite the numerous applications of IRMS to a wide range of forensic materials, its implementation in a forensic framework is less straightforward than it appears. In addition, each laboratory has developed its own strategy of analysis on calibration, sequence design, standards utilisation and data treatment without a clear consensus. Through the experience acquired from research undertaken in different forensic fields, we propose a methodological framework of the whole process using IRMS methods. We emphasize the importance of considering isotopic results as part of a whole approach, when applying this technology to a particular forensic issue. The process is divided into six different steps, which should be considered for a thoughtful and relevant application. The dissection of this process into fundamental steps, further detailed, enables a better understanding of the essential, though not exhaustive, factors that have to be considered in order to obtain results of quality and sufficiently robust to proceed to retrospective analyses or interlaboratory comparisons.

Potential of IRMS technology for tracing gamma-butyrolactone (GBL).

Popularity of gamma-hydroxybutyric acid (GHB) is fairly stable among drug users, while the consumption of its chemical precursor, gamma-butyrolactone (GBL), is a growing phenomenon. Although conventional analytical methods allow to detect this substance in various matrices, linking a trace and a source is still a difficult challenge. However, as several synthesis pathways and chemical precursors exist for the production of GBL, its carbon isotopic signature may vary extensively. For that purpose, a method has been developed to determine the carbon isotopes content of GBL by means of gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). The delta(13)C-values of 19 bulk samples purchased worldwide were in the range from -23.1 to -45.8 per thousand (SD<0.3 per thousand). Furthermore, testing on the purification of GBL by distillation has not been found to be consistent with such a large range of delta(13)C-values, which are likely to result from the isotopic composition of the organic precursors used to produce GBL together with the kinetic isotope effect associated with the synthesis routes. Finally, inter- and intra-variability measurements of the delta(13)C-values demonstrated the high potential of IRMS for discriminating between seizures of GBL and for source determination.