1,486 research outputs found

    Introduction of isotope ratio mass spectrometry (IRMS) for the forensic analysis of explosives

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    University of Technology, Sydney. Faculty of Science.The key role of a forensic scientist is to assist in determining whether a crime has been committed and, if so, assist in the identification of the offender. It is a commonly held belief that a particular item can be conclusively linked to a specific person, place or object. Unfortunately, this is often not an achievable outcome. An evaluation was undertaken to determine if isotope ratio mass spectrometry (IRMS) could assist in the investigation of complex forensic cases by providing a level of discrimination not achievable utilising traditional forensic techniques. The focus of the research was on ammonium nitrate (AN), a common oxidiser used in improvised explosive mixtures. A secondary objective was to adapt the methods and protocols developed for AN for the analysis of other threat explosives, namely triacetone triperoxide (TATP) and pentaerythritol tetranitrate (PETN). The potential of IRMS was demonstrated through the successful development and validation of a method for the measurement of bulk nitrogen isotope ratios in AN samples and the subsequent development of an AN classification scheme based on nitrogen stable isotopes to assist in determining the potential manufacturer (in the case of an Australian source). Although the discrimination was limited, the classification scheme could be used as an investigative aid. A comparison of nitrogen isotope ratios from intact AN prill samples with those from post-blast AN prill residues highlighted that the nitrogen isotopic composition of the prills is not maintained; hence, this is a limitation of the technique for explosives analysis. Combining oxygen and hydrogen stable isotope ratios permitted the differentiation of AN prills from three different Australian manufacturers. Groups corresponding to source were also identified in the overseas AN prill samples. When these values were combined with the nitrogen isotope values, there was some level of discrimination (within the scope of the samples analysed) between prills manufactured in Australia and those manufactured overseas. The IRMS procedures developed through this research were successfully applied to the analysis of both TATP and PETN. Preliminary results of a limited sample set demonstrated that TATP sources may be discriminated utilising carbon and hydrogen isotopes alone, and in combination with oxygen isotopes. Preliminary results for PETN samples demonstrated that different sources can be discriminated based on carbon and nitrogen isotope ratios. A laboratory inter-comparison for carbon and nitrogen bulk stable isotope ratios across seven Australian and New Zealand IRMS laboratories was conducted and provides an initial snapshot of the potential for traceability. A Microsoft Access 2.0 database was developed for the IRMS data and its successful operation demonstrated. This research highlights the significant value of IRMS in complex forensic investigations, particularly with respect to explosives analysis. Further research is justified to continue the path towards broader forensic casework application of the technique

    The suitcase, the samurai sword and the pumpkin: Asian crime and news media treatment

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    In 2005 and 2007, two high profile crimes were reported in the New Zealand media. The first case involved the murder of a young Chinese student, Wan Biao, whose dismembered body was discovered in a suitcase. The second case involved domestic violence in which a Chinese man murdered his wife and fled the scene with their young daughter - who the press later dubbed 'Pumpkin' when she was found abandoned in Melbourne, Australia. The authors discuss how news and current affairs programmes decontextualise 'Asian' stories to portray a clear divide between the 'New Zealand' public and the separate 'Asian other'. Asians are portrayed as a homogenous group and the media fails to distinguish between Asians as victims of crimes as a separate category to Asians as perpetrators of crimes. This may have consequences for the New Zealand Asian communities and the wider New Zealand society as a whole

    An inexact dual logarithmic barrier method for solving sparse semidefinite programs

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    A dual logarithmic barrier method for solving large, sparse semidefinite programs is proposed in this paper. The method avoids any explicit use of the primal variable X and therefore is well-suited to problems with a sparse dual matrix S. It relies on inexact Newton steps in dual space which are computed by the conjugate gradient method applied to the Schur complement of the reduced KKT system. The method may take advantage of low-rank representations of matrices Ai to perform implicit matrix-vector products with the Schur complement matrix and to compute only specific parts of this matrix. This allows the construction of the partial Cholesky factorization of the Schur complement matrix which serves as a good preconditioner for it and permits the method to be run in a matrix-free scheme. Convergence properties of the method are studied and a polynomial complexity result is extended to the case when inexact Newton steps are employed. A Matlab-based implementation is developed and preliminary computational results of applying the method to maximum cut and matrix completion problems are reported

    Neuromodulation and the role of electrodiagnostic techniques

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    Electrodiagnostic techniques have been utilized in surgery since the early 1960s. These techniques have been primarily used in neurosurgery; however, with the introduction of neuromodulation for voiding dysfunction, these techniques have now found their way into the field of female pelvic medicine. This article will review techniques applicable to evaluate pelvic floor function as it relates to neuromodulation. It will also review the literature describing how these techniques are used to help determine appropriate candidates as well as improve surgical outcomes. A PubMed search was conducted using the terms neuromodulation, Interstim, electrodiagnosis, electrodiagnostic techniques, electromyography with limits to the pelvic floor, and voiding dysfunction. Eight articles and three abstracts were found that directly related to the use of electrodiagnostic techniques as they apply to neuromodulation. Electrodiagnostic techniques may play a role in helping predict appropriate candidates for neuromodulation as well as improve surgical outcomes

    Yours ever (well, maybe): Studies and signposts in letter writing

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    Electronic mail and other digital communications technologies seemingly threaten to end the era of handwritten and typed letters, now affectionately seen as part of snail mail. In this essay, I analyze a group of popular and scholarly studies about letter writing-including examples of pundits critiquing the use of e-mail, etiquette manuals advising why the handwritten letter still possesses value, historians and literary scholars studying the role of letters in the past and what it tells us about our present attitudes about digital communications technologies, and futurists predicting how we will function as personal archivists maintaining every document including e-mail. These are useful guideposts for archivists, providing both a sense of the present and the past in the role, value and nature of letters and their successors. They also provide insights into how such documents should be studied, expanding our gaze beyond the particular letters, to the tools used to create them and the traditions dictating their form and function. We also can discern a role for archivists, both for contributing to the literature about documents and in using these studies and commentaries, suggesting not a new disciplinary realm but opportunities for new interdisciplinary work. Examining a documentary form makes us more sensitive to both the innovations and traditions as it shifts from the analog to the digital; we can learn not to be caught up in hysteria or nostalgia about one form over another and archivists can learn about what they might expect in their labors to document society and its institutions. At one time, paper was part of an innovative technology, with roles very similar to the Internet and e-mail today. It may be that the shifts are far less revolutionary than is often assumed. Reading such works also suggests, finally, that archivists ought to rethink how they view their own knowledge and how it is constructed and used. © 2010 Springer Science+Business Media B.V

    Relationship Between Non-Hodgkin's Lymphoma and Blood Levels of Epstein-Barr Virus in Children in North-Western Tanzania: A Case Control Study.

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    Non-Hodgkin's Lymphomas (NHL) are common in African children, with endemic Burkitt's lymphoma (BL) being the most common subtype. While the role of Epstein-Barr Virus (EBV) in endemic BL is known, no data are available about clinical presentations of NHL subtypes and their relationship to Human Immunodeficiency Virus (HIV) infection and Epstein Barr Virus (EBV) load in peripheral blood of children in north-western, Tanzania. A matched case control study of NHL subtypes was performed in children under 15 years of age and their respective controls admitted to Bugando Medical Centre, Sengerema and Shirati district designated hospitals in north-western, Tanzania, between September 2010 and April 2011. Peripheral blood samples were collected on Whatman 903 filter papers and EBV DNA levels were estimated by multiplex real-time PCR. Clinical and laboratory data were collected using a structured data collection tool and analysed using chi-square, Fisher and Wilcoxon rank sum tests where appropriate. The association between NHL and detection of EBV in peripheral blood was assessed using conditional logistic regression model and presented as odds ratios (OR) and 95% confidence intervals (CI). A total of 35 NHL cases and 70 controls matched for age and sex were enrolled. Of NHLs, 32 had BL with equal distribution between jaw and abdominal tumour, 2 had large B cell lymphoma (DLBCL) and 1 had NHL-not otherwise specified (NHL-NOS). Central nervous system (CNS) presentation occurred only in 1 BL patient; 19 NHLs had stage I and II of disease. Only 1 NHL was found to be HIV-seropositive. Twenty-one of 35 (60%) NHL and 21 of 70 (30%) controls had detectable EBV in peripheral blood (OR = 4.77, 95% CI 1.71 - 13.33, p = 0.003). In addition, levels of EBV in blood were significantly higher in NHL cases than in controls (p = 0.024). BL is the most common childhood NHL subtype in north-western Tanzania. NHLs are not associated with HIV infection, but are strongly associated with EBV load in peripheral blood. The findings suggest that high levels of EBV in blood might have diagnostic and prognostic relevance in African children

    Automatic contour propagation using deformable image registration to determine delivered dose to spinal cord in head-and-neck cancer radiotherapy.

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    To determine delivered dose to the spinal cord, a technique has been developed to propagate manual contours from kilovoltage computed-tomography (kVCT) scans for treatment planning to megavoltage computed-tomography (MVCT) guidance scans. The technique uses the Elastix software to perform intensity-based deformable image registration of each kVCT scan to the associated MVCT scans. The registration transform is then applied to contours of the spinal cord drawn manually on the kVCT scan, to obtain contour positions on the MVCT scans. Different registration strategies have been investigated, with performance evaluated by comparing the resulting auto-contours with manual contours, drawn by oncologists. The comparison metrics include the conformity index (CI), and the distance between centres (DBC). With optimised registration, auto-contours generally agree well with manual contours. Considering all 30 MVCT scans for each of three patients, the median CI is [Formula: see text], and the median DBC is ([Formula: see text]) mm. An intra-observer comparison for the same scans gives a median CI of [Formula: see text] and a DBC of ([Formula: see text]) mm. Good levels of conformity are also obtained when auto-contours are compared with manual contours from one observer for a single MVCT scan for each of 30 patients, and when they are compared with manual contours from six observers for two MVCT scans for each of three patients. Using the auto-contours to estimate organ position at treatment time, a preliminary study of 33 patients who underwent radiotherapy for head-and-neck cancers indicates good agreement between planned and delivered dose to the spinal cord.CRUK, Singapore Government, Addenbrooke's Charitable Trust, Cambridge Biomedical Research Centr

    A ‘quiet revolution’? The impact of Training Schools on initial teacher training partnerships

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    This paper discusses the impact on initial teacher training of a new policy initiative in England: the introduction of Training Schools. First, the Training School project is set in context by exploring the evolution of a partnership approach to initial teacher training in England. Ways in which Training Schools represent a break with established practice are considered together with their implications for the dominant mode of partnership led by higher education institutions (HEIs). The capacity of Training Schools to achieve their own policy objectives is examined, especially their efficacy as a strategy for managing innovation and the dissemination of innovation. The paper ends by focusing on a particular Training School project which has adopted an unusual approach to its work and enquires whether this alternative approach could offer a more profitable way forward. During the course of the paper, five different models of partnership are considered: collaborative, complementary, HEI-led, school-led and partnership within a partnership

    Health-Related Quality of Life and Experiences of Sarcoma Patients during the COVID-19 Pandemic

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    Sarcomas are rare cancers with a spectrum of clinical needs and outcomes. We investigated care experiences and health-related quality of life (HRQoL) in sarcoma patients during the COVID-19 pandemic. Patients with appointments during the first two months of the UK lockdown were invited to complete a survey. Questions included views on care modifications, COVID-19 worry and psychosocial impact, and EORTC-QLQ-C30 items. 350 patients completed the survey; median age 58 (16–92) years. Care modifications included telemedicine (74%) and postponement of appointments (34%), scans (34%) or treatment (10%). Most felt the quality of care was not affected (72%), however, social life (87%) and emotional wellbeing (41%) were affected. Worry about COVID-19 infection was moderately high (mean 5.8/10) and significantly related to higher cancer-related worry; associated with lower emotional functioning irrespective of treatment intent. Curative patients (44%) with low resilient coping scores had significantly higher COVID-19 worry. Patients who did not know their treatment intent (22%) had significantly higher COVID-19 worry and insomnia. In summary, care experiences were generally positive; however, cancer-related worry, low resilient coping and uncertainty about treatment intent were associated with COVID-19 worry. These patients may benefit from additional psychological support during the pandemic and beyond
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