Chemical profiling of different hashish seizures by gas chromatography-mass spectrometry and statistical methodology: a case report

Limited information is available regarding the methodology required to characterize hashish seizures for assessing the presence or the absence of a chemical link between two seizures. This casework report presents the methodology applied for assessing that two different police seizures were coming from the same block before this latter one was split. The chemical signature was extracted using GC-MS analysis and the implemented methodology consists in a study of intra- and inter-variability distributions based on the measurement of the chemical profiles similarity using a number of hashish seizures and the calculation of the Pearson correlation coefficient. Different statistical scenarios (i.e., a combination of data pretreatment techniques and selection of target compounds) were tested to find the most discriminating one. Seven compounds showing high discrimination capabilities were selected on which a specific statistical data pretreatment was applied. Based on the results, the statistical model built for comparing the hashish seizures leads to low error rates. Therefore, the implemented methodology is suitable for the chemical profiling of hashish seizures.

Health literacy and substance use in young Swiss men.

OBJECTIVES: The purpose of the present study was to describe health literacy and its association with substance use among young men. METHODS: The present study was part of the Cohort Study on Substance Use Risk Factors that included 11,930 Swiss males participating in initial screening from August 2010 to July 2011. Self-completed questionnaires covered use of three substances and three components of health literacy. RESULTS: Roughly 22 % reported having searched the Internet for health information and 16 % for information on substances over the past 12 months. At-risk and not at-risk users of alcohol (adjusted odds ratio (AOR) = 2.50 and 1.46), tobacco (AOR = 2.51 and 1.79) and cannabis (AOR = 4.86 and 3.53) searched for information about substances significantly more often via the Internet than abstainers. Furthermore, at-risk users reported better knowledge of risks associated with substance use and a marginally better ability to understand health information than abstainers. CONCLUSIONS: Substance users appear to be more informed and knowledgeable about the risks of substance use than non-users. Consequently, interventions that focus only on information provision may be of limited benefit for preventing substance use.

Illicit drug profiling, reflection on statistical comparisons

This paper presents reflexions about statistical considerations on illicit drug profiling and more specifically about the calculation of threshold for determining of the seizure are linked or not. The specific case of heroin and cocaine profiling is presented with the necessary details on the target profiling variables (major alkaloids) selected and the analytical method used. Statistical approach to compare illicit drug seizures is also presented with the introduction of different scenarios dealing with different data pre-treatment or transformation of variables.The main aim consists to demonstrate the influence of data pre-treatment on the statistical outputs. A thorough study of the evolution of the true positive rate (TP) and the false positive rate (FP) in heroin and cocaine comparison is then proposed to investigate this specific topic and to demonstrate that there is no universal approach available and that the calculations have to be revaluate for each new specific application.

Children Order Statistical Bulletin 2005 (PDF 278 KB)

Statistical information based on the Children Order returns for NI up to 31st March 2005

Statistical evaluation of the influence of writing postures on on-line signatures. Study of the impact of time.

The aim of this study is to investigate the influence of unusual writing positions on a person's signature, in comparison to a standard writing position. Ten writers were asked to sign their signature six times, in each of four different writing positions, including the standard one. In order to take into consideration the effect of the day-to-day variation, this same process was repeated over 12 sessions, giving a total of 288 signatures per subject. The signatures were collected simultaneously in an off-line and on-line acquisition mode, using an interactive tablet and a ballpoint pen. Unidimensional variables (height to width ratio; time with or without in air displacement) and time-dependent variables (pressure; X and Y coordinates; altitude and azimuth angles) were extracted from each signature. For the unidimensional variables, the position effect was assessed through ANOVA and Dunnett contrast tests. Concerning the time-dependent variables, the signatures were compared by using dynamic time warping, and the position effect was evaluated through classification by linear discriminant analysis. Both of these variables provided similar results: no general tendency regarding the position factor could be highlighted. The influence of the position factor varies according to the subject as well as the variable studied. The impact of the session factor was shown to cover the impact that could be ascribed to the writing position factor. Indeed, the day-to-day variation has a greater effect than the position factor on the studied signature variables. The results of this study suggest guidelines for best practice in the area of signature comparisons and demonstrate the importance of a signature collection procedure covering an adequate number of sampling sessions, with a sufficient number of samples per session.

Health and Social Care in Northern Ireland: A statistical Profile

2002 edition

Statistical tests for scaling in the inter-event times of earthquakes in California

We explore in depth the validity of a recently proposed scaling law for earthquake inter-event time distributions in the case of the Southern California, using the waveform cross-correlation catalog of Shearer et al. Two statistical tests are used: on the one hand, the standard two-sample Kolmogorov-Smirnov test is in agreement with the scaling of the distributions. On the other hand, the one-sample Kolmogorov-Smirnov statistic complemented with Monte Carlo simulation of the inter-event times, as done by Clauset et al., supports the validity of the gamma distribution as a simple model of the scaling function appearing on the scaling law, for rescaled inter-event times above 0.01, except for the largest data set (magnitude greater than 2). A discussion of these results is provided.

Diagnostic and statistical manual of mental disorders : DSM-IV-TR.

Since the "DSM-IV(R)" was published in 1994, we've seen many advances in our knowledge of psychiatric illness. This "Text Revision" incorporates information culled from a comprehensive literature review of research about mental disorders published since "DSM-IV(R)" was completed in 1994. Updated information is included about the associated features, culture, age, and gender features, prevalence, course, and familial pattern of mental disorders. The "DSM-IV-TR(R)" brings this essential diagnostic tool up-to-date, to promote effective diagnosis, treatment, and quality of care. Now you can get all the essential diagnostic information you rely on from the "DSM-IV(R)" along with important updates not found in the 1994 edition. Stay current with important updates to the "DSM-IV-TR(R)": Benefit from new research into Schizophrenia, Asperger's Disorder, and other conditions Utilize additional information about the epidemiology and other facets of DSM conditions Update ICD-9-CM codes implemented since 1994 (including Conduct Disorder, Dementia, Somatoform Disorders) DSM-IV-TR(R), the handheld version of the "Diagnostic and Statistical Manual of Mental Disorders, "Fourth Edition, Text Revision, is now available for both Palm OS and PocketPC handhelds. This Text Revision incorporates information culled from a comprehensive literature review of research about mental disorders and includes associated features, culture, age, and gender features, prevalence, course, and familial pattern of mental disorders.This resource was contributed by The National Documentation Centre on Drug Use.

Indexes and boundaries for "quantitative significance" in statistical decisions.

Boundaries for delta, representing a "quantitatively significant" or "substantively impressive" distinction, have not been established, analogous to the boundary of alpha, usually set at 0.05, for the stochastic or probabilistic component of "statistical significance". To determine what boundaries are being used for the "quantitative" decisions, we reviewed pertinent articles in three general medical journals. For each contrast of two means, contrast of two rates, or correlation coefficient, we noted the investigators' decisions about stochastic significance, stated in P values or confidence intervals, and about quantitative significance, indicated by interpretive comments. The boundaries between impressive and unimpressive distinctions were best formed by a ratio of greater than or equal to 1.2 for the smaller to the larger mean in 546 comparisons, by a standardized increment of greater than or equal to 0.28 and odds ratio of greater than or equal to 2.2 in 392 comparisons of two rates; and by an r value of greater than or equal to 0.32 in 154 correlation coefficients. Additional boundaries were also identified for "substantially" and "highly" significant quantitative distinctions. Although the proposed boundaries should be kept flexible, indexes and boundaries for decisions about "quantitative significance" are particularly useful when a value of delta must be chosen for calculating sample size before the research is done, and when the "statistical significance" of completed research is appraised for its quantitative as well as stochastic components.

Literacy and Numeracy Learning for Life

Literacy and Numeracy for Learning and Life is the national strategy to improve literacy and numeracy standards among children and young people in the education system. This strategy seeks to address significant concerns about how well our young people are developing the literacy and numeracy skills that they will need to participate fully in the education system, to live satisfying and rewarding lives, and to participate as active and informed citizens in our society.

Literacy and Numeracy Learning for Life - Summary

In July 2011 the Minister for education launched Literacy and Numeracy for Learning and Life – the national strategy to improve literacy and numeracy among children and young people. The strategy was developed following an extensive consultation process and contributions from individuals, schools, groups and organisations. This leaflet gives a flavour of the key parts of the Strategy with access to the full document on the Department’s website.

Review of ALCES funded Adult Literacy Provision

Following the publication of the International Adult Literacy Survey (IALS), the White Paper on Adult Education set targets for the participation of adults with low levels of literacy and numeracy in VEC provision. These participation targets have been attained. It is not known if the skill levels of the Irish population have changed since 1995 but the publication of the results of the OECD’s Programme for the International Assessment of Adult Competencies (PIAAC) in October 2013 will provide this information. The Skills Strategy and other Government policy statements relating to activation measures propose that an additional 500,000 individuals within the workforce need to progress by at least one level on the National Framework of Qualifications (NFQ) by 2020. While no new overall strategy for the development of Adult Literacy in Ireland has been devised since the publication of the White Paper in 2000, there have been a number of specific initiatives taken by Government which complement the initial provision framework (Intensive Literacy (ITABE), DEIS Family Literacy, projects focused on the workplace). Blended and distance learning initiatives have also been supported. These issues should inform the development of any new Adult Literacy strategy by SOLAS.