4,017 research outputs found

    SCAFFOLDING FOR IMPACT: ACTIVE LEARNING IN FORENSIC EDUCATION

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    Forensic science programs attract students from a range of scientific disciplines including chemistry, biology, psychology and engineering. At the tertiary level, these students are expected to demonstrate a mastery of forensic principles with the ability to apply them in practice. However, there has been little investigation of effective pedagogical approaches to achieve these outcomes in forensic education. Active learning has long been recognised within other scientific disciplines as an effective means of promoting mastery, motivation, and higher-order thinking skills. Despite this, active learning has yet to be systematically evaluated within a forensic context. This project applied a mixed methods approach to evaluate how active learning strategies influence students’ academic achievement and attitudes towards learning in an introductory forensic science unit. The outcomes and implications of these results will be discussed in relation to establishing scholarly practices for forensic education and training

    Design of LabVIEW®-based software for the control of sequential injection analysis instrumentation for the determination of morphine

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    LabVIEW®-based software for the automation of a sequential injection analysis instrument for the determination of morphine is presented. Detection was based on its chemiluminescence reaction with acidic potassium permanganate in the presence of sodium polyphosphate. The calibration function approximated linearity (range 5 × 10-10 to 5 × 10-6 M) with a line of best fit of y=1.05x+8.9164 (R2 =0.9959), where y is the log10 signal (mV) and x is the log10 morphine concentration (M). Precision, as measured by relative standard deviation, was 0.7% for five replicate analyses of morphine standard (5 × 10-8 M). The limit of detection (3σ) was determined as 5 × 10-11 M morphine

    Assessing a novel contact heater as a new method of recovering explosives traces from porous surfaces

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    It can be very challenging to recover explosives traces from porous surfaces, such as clothing and car seats, compared to non-porous surfaces. The contact heater has been developed as a novel instrument designed to recover explosives traces from porous surfaces. Samples are taken by heating and drawing air across a surface, with the air flowing through a sampling cartridge containing adsorbent polymer beads, which act to trap any recovered explosive material. Any collected explosive can then be eluted from this cartridge using a solvent, prior to analysis. This paper outlines work performed to evaluate the usefulness of the contact heater with regards to the recovery of explosives traces from porous materials. Ethylene glycol dinitrate (EGDN) and triacetone triperoxide (TATP) were chosen as two representative explosives for this study. Quantification was performed using GC–MS for EGDN and LC–MS/MS for TATP. Different sampling temperatures, sampling times and elution solvents were investigated. Recovery was trialled from leather, carpet and denim. Recoveries of up to 71% were obtained following optimisation. It was also possible to recover TATP from fabrics exposed to TATP vapour in a vapour-laden jar up to two hours after exposure. The contact heater therefore appears to be a very useful tool for the recovery of explosives traces from porous materials

    Characterization of Automotive Paint Clear Coats by Ultraviolet Absorption Microspectrophotometry with Subsequent Chemometric Analysis

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    Clear coats have been a staple in automobile paints for almost thirty years and are of forensic interest when comparing transferred and native paints. However, the ultraviolet (UV) absorbers in these paint layers are not typically characterized using UV microspectrophotometry, nor are the results studied using multivariate statistical methods. In this study, measurements were carried out by UV microspectrophotometry on 71 samples from American and Australian automobiles, with subsequent chemometric analysis of the absorbance spectra. Sample preparation proved to be vital in obtaining accurate absorbance spectra and a method involving peeling the clear coat layer and not using a mounting medium was preferred. Agglomerative hierarchical clustering indicated three main groups of spectra, corresponding to spectra with one, two, and three maxima. Principal components analysis confirmed this clustering and the factor loadings indicated that a substantial proportion of the variance in the data set originated from specific spectral regions (230–265 nm, 275–285 nm, and 300–370 nm). The three classes were well differentiated using discriminant analysis, where the cross-validation accuracy was 91.6% and the external validation accuracy was 81.1%. However, results showed no correlation between the make, model, and year of the automobiles

    A regional coupled approach to water cycle prediction during winter 2013/14 in the United Kingdom

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    A regional coupled approach to water cycle prediction is demonstrated for the 4-month period from November 2013 to February 2014. This provides the first multi-component analysis of precipitation, soil moisture, river flow and coastal ocean simulations produced by an atmosphere-land-ocean coupled system focussed on the United Kingdom (UK), running with horizontal grid spacing of around 1.5 km across all components. The Unified Model atmosphere component, in which convection is explicitly simulated, reproduces the observed UK rainfall accumulation (r2 of 0.95 for water day accumulation), but there is a notable bias in its spatial distribution—too dry over western upland areas and too wet further east. The JULES land surface model soil moisture state is shown to be in broad agreement with a limited number of cosmic-ray neutron probe observations. A comparison of observed and simulated river flow shows the coupled system is useful for predicting broad scale features, such as distinguishing high and low flow regions and times during the period of interest but are less accurate than optimized hydrological models. The impact of simulated river discharge on NEMO model simulations of coastal ocean state is explored in the coupled modelling framework, with comparisons provided relative to experiments using climatological river input and no river input around the UK coasts. Results show that the freshwater flux around the UK contributes of order 0.2 psu to the mean surface salinity, and comparisons to profile observations give evidence of an improved vertical structure when applying simulated flows. This study represents the first assessment of the coupled system performance from a hydrological perspective, with priorities for future model developments and challenges for evaluation of such systems discussed

    Modular finite <i>W</i>-algebras

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    Abstract Let k{\mathbb{k}} be an algebraically closed field of characteristic p &gt; 0 and let G be a connected reductive algebraic group over k{\mathbb{k}}. Under some standard hypothesis on G, we give a direct approach to the finite W-algebra U(g,e)U(\mathfrak{g},e) associated to a nilpotent element e∈g=Lie Ge \in \mathfrak{g} = \textrm{Lie}\ G. We prove a PBW theorem and deduce a number of consequences, then move on to define and study the p-centre of U(g,e)U(\mathfrak{g},e), which allows us to define reduced finite W-algebras Uη(g,e)U_{\eta}(\mathfrak{g},e) and we verify that they coincide with those previously appearing in the work of Premet. Finally, we prove a modular version of Skryabin’s equivalence of categories, generalizing recent work of the second author.</jats:p

    Fluid/solid transition in a hard-core system

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    We prove that a system of particles in the plane, interacting only with a certain hard-core constraint, undergoes a fluid/solid phase transition

    The Species Effect:Differential Sphingosine-1-Phosphate Responses in the Bone in Human Versus Mouse

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    he deterioration of osteoblast-led bone formation and the upregulation of osteoclast-regulated bone resorption are the primary causes of bone diseases, including osteoporosis. Numerous circulating factors play a role in bone homeostasis by regulating osteoblast and osteoclast activity, including the sphingolipid—sphingosine-1-phosphate (S1P). However, to date no comprehensive studies have investigated the impact of S1P activity on human and murine osteoblasts and osteoclasts. We observed species-specific responses to S1P in both osteoblasts and osteoclasts, where S1P stimulated human osteoblast mineralisation and reduced human pre-osteoclast differentiation and mineral resorption, thereby favouring bone formation. The opposite was true for murine osteoblasts and osteoclasts, resulting in more mineral resorption and less mineral deposition. Species-specific differences in osteoblast responses to S1P were potentially explained by differential expression of S1P receptor 1. By contrast, human and murine osteoclasts expressed comparable levels of S1P receptors but showed differential expression patterns of the two sphingosine kinase enzymes responsible for S1P production. Ultimately, we reveal that murine models may not accurately represent how human bone cells will respond to S1P, and thus are not a suitable model for exploring S1P physiology or potential therapeutic agents

    ATR-FTIR Spectroscopic Studies of Polymer-Based Identification Cards

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    Counterfeit production of polymer identity cards poses a significant economic cost to society and a threat to national security. Identifying these counterfeits is a challenge for ‘frontline’ personnel who lack training in specialised document examination. This study investigates the use of attenuated total reflectance Fourier Transform infrared (ATR-FTIR) spectroscopy with chemometrics as a potential approach to assessing polymer card authenticity. In situ analysis of several cards found that differentiation could be achieved based on the core polymer composition. A chemometric model was thus built for three driver’s licence series produced in Western Australia and tested using a separate set of seven licences. The majority of test samples were correctly matched to the series of issue, with atypical samples recognisable based on their discriminant values. Synchrotron FTIR imaging revealed that differentiation between each series was possibly related to the adhesive used between the core layers. The approach presented in this work has the potential to be developed as a rapid screening method to identify suspect polymer cards warranting further examination
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