132 research outputs found

    A Ground Truth Data Set of Gas Chromatography mass spectrometry (GCMS) Analysed Synthesised Methylenedioxymethylamphetamine (MDMA)

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    An open source format data set of Methylenedioxymethylamphetamine. This data set was derived from a PhD project which involved the repetitive chemical synthesis of a series of methylenedioxymethylamphetamine (MDMA) samples following a series of known synthetic chemical routes. Controlled drug samples are normally chemically analysed to determine their identity and in some cases, their purity. There are also circumstances where a more broad chemical characterisation of drug samples may also be required. This involves investigating the chemical impurities that may be present in a drug sample as a consequence of their synthesis. This ‘impurity or drug profiling’ can be derived from drugs which are synthesised chemically or extracted from plant materials and then modified chemically. Impurity profiling can provide some insight into the synthetic methods used and sometimes the starting chemicals used. We report on the data generated from repetitive (n=18) synthesis of ecstasy (methylenedioxymethylamphetamine or MDMA) made by three different synthetic methods. Each data sample is expressed in multiple formats. Data are made available under a Creative Commons Attribution 4.0 International (CC BY 4.0) license

    Supporting data for “A Systematic Study of the In Vitro Pharmacokinetics and Estimated Human In Vivo Clearance of Indole and Indazole-3-Carboxamide Synthetic Cannabinoid Receptor Agonists Detected on the Illicit Drug Market”

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    This dataset comprises supporting information for the peer-reviewed manuscript: A Systematic Study of the In Vitro Pharmacokinetics and Estimated Human In Vivo Clearance of Indole and Indazole-3-Carboxamide Synthetic Cannabinoid Receptor Agonists Detected on the Illicit Drug Market published in the journal ‘Molecules’

    Delta-9-tetrahydrocannabinol (THC) Measurement Uncertainty Dataset

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    Method validation data generated as part of quantifying the measurement uncertainty of delta-9-tetrahydrocannabinol (THC, the main active ingredient of cannabis) in whole Blood using SPE and LC/MS/MS Key words calibration curve, coverage factor, method validation, method precision, standard solutio

    Comparing Categorical and Probabilistic Fingerprint Evidence

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    Fingerprint examiners traditionally express conclusions in categorical terms, opining that impressions do or do not originate from the same source. Recently, probabilistic conclusions have been proposed, with examiners estimating the probability of a match between recovered and known prints. This study presented a nationally representative sample of jury‐eligible adults with a hypothetical robbery case in which an examiner opined on the likelihood that a defendant\u27s fingerprints matched latent fingerprints in categorical or probabilistic terms. We studied model language developed by the U.S. Defense Forensic Science Center to summarize results of statistical analysis of the similarity between prints. Participant ratings of the likelihood the defendant left prints at the crime scene and committed the crime were similar when exposed to categorical and strong probabilistic match evidence. Participants reduced these likelihoods when exposed to the weaker probabilistic evidence, but did not otherwise discriminate among the prints assigned different match probabilities

    Doing ESRC Data Better: Appendices

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    Appendix 1 Survey responses: tables showing frequency of responses to each of the statements Appendix 2 Survey respondent characteristics Appendix 3 Survey questions Appendix 4 Focus group guiding questions and topic guide

    Doing ESRC Data Better: Appendices

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    Appendix 1 Survey responses: tables showing frequency of responses to each of the statements Appendix 2 Survey respondent characteristics Appendix 3 Survey questions Appendix 4 Focus group guiding questions and topic guide

    Psychometric properties of the Spanish version of the Psychopathy Checklist: Youth Version

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    Acord transformatiu CRUE-CSICThe current study examined the psychometric properties (factor structure, reliability and validity) of the Psychopathy Checklist: Youth Version (PCL:YV; Forth et al., 2003) in Spanish samples of male justice-involved youths between 15 and 22-years old. The PCL:YV was administered to two groups of youths who were incarcerated (n = 62; n = 95) and a sample of youth on probation (n = 122). Confirmatory factor analyses showed acceptable-to-good fit for three- and four-factor models. The four-factor hierarchical model with a second-order higher factor representing the whole psychopathy construct was considered for further analyses. PCL:YV scores showed high internal consistency and inter-rater reliability. Low-to-moderate convergence with other measures of psychopathic traits evinced an adequate convergent validity. Convergent and discriminant validity of the PCL:YV total scores were also confirmed considering several measures of psychopathology and personality traits. Importantly, the differential external correlates of the PCL:YV factors provide support for a multidimensional conceptualization of the psychopathy construct. Altogether, these results reveal adequate psychometric properties of the PCL:YV in Spanish population of justice-involved youths and justifies its use to assess psychopathic traits in this kind of populations

    The transfer of diatoms from freshwater to footwear materials: An experimental study assessing transfer, persistence, and extraction methods for forensic reconstruction

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    In recent years there has been growing interest in environmental forms of trace evidence, and ecological trace evidence collected from footwear has proved valuable within casework. Simultaneously, there has been growing awareness of the need for empirical experimentation to underpin forensic inferences. Diatoms are unicellular algae, and each cell (or ‘frustule’) consists of two valves which are made of silica, a robust material that favours their preservation both in sediments and within forensic scenarios. A series of experiments were carried out to investigate the transfer and persistence of diatoms upon common footwear materials, a recipient surface that has historically been overlooked by studies of persistence. The effectiveness of two novel extraction techniques (jet rinsing, and heating and agitation with distilled water) was compared to the established extraction technique of hydrogen peroxide digestion, for a suite of five common footwear materials: canvas, leather, and ‘suede’ (representing upper materials), and rubber and polyurethane (representing sole materials). It was observed that the novel extraction technique of heating and agitation with distilled water did not extract fewer diatom valves, or cause increased fragmentation of valves, when compared to peroxide digestion, suggesting that the method may be viable where potentially hazardous chemical reactions may be encountered with the peroxide digestion method. Valves could be extracted from all five footwear materials after 3 min of immersion, and more valves were extracted from the rougher, woven upper materials than the smoother sole materials. Canvas yielded the most valves (a mean of 2511/cm2) and polyurethane the fewest (a mean of 15/cm2). The persistence of diatoms on the three upper materials was addressed with a preliminary pilot investigation, with ten intervals sampled between 0 and 168 h. Valves were seen to persist in detectable quantities after 168 h on all three upper materials. However, some samples produced slides with no valves, and the earliest time after which no diatom valves were found was 4 h after the transfer. Analysis of the particle size distributions over time, by image analysis, suggests that the retention of diatoms may be size-selective; after 168 h, no particles larger than 200 μm2 could be found on the samples of canvas, and > 95% of the particles on the samples of suede were less than or equal to 200 μm2. A pilot investigation into the effects of immersion interval was carried out upon samples of canvas. Greater numbers of valves were extracted from the samples with longer immersion intervals, but even after 30 s, > 500 valves could be recovered per cm2, suggesting that footwear may be sampled for diatoms even if the contact with a water body may have been brief. These findings indicate that, if the variability within and between experimental runs can be addressed, there is significant potential for diatoms to be incorporated into the trace analysis of footwear and assist forensic reconstructions
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