164 research outputs found

    Data remanence and digital forensic investigation for CUDA Graphics Processing Units

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    This paper investigates the practicality of memory attacks on commercial Graphics Processing Units (GPUs). With recent advances in the performance and viability of using GPUs for various highly-parallelised data processing tasks, a number of security challenges are raised. Unscrupulous software running subsequently on the same GPU, either by the same user, or another user, in a multi-user system, may be able to gain access to the contents of the GPU memory. This contains data from previous program executions. In certain use-cases, where the GPU is used to offload intensive parallel processing such as pattern matching for an intrusion detection system, financial systems, or cryptographic algorithms, it may be possible for the GPU memory to contain privileged data, which would ordinarily be inaccessible to an unprivileged application running on the host computer. With GPUs potentially yielding access to confidential information, existing research in the field is built upon, to investigate the practicality of extracting data from global, shared and texture memory, and retrieving this data for further analysis. These techniques are also implemented on various GPUs using three different Nvidia CUDA versions. A novel methodology for digital forensic examination of GPU memory for remanent data is then proposed, along with some suggestions and considerations towards countermeasures and anti-forensic technique

    Inverse modelling for predicting both water and nitrate movement in a structured-clay soil (Red Ferrosol)

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    Soil physical parameter calculation by inverse modelling provides an indirect way of estimating the unsaturated hydraulic properties of soils. However many measurements are needed to provide sufficient data to determine unknown parameters. The objective of this research was to assess the use of unsaturated water flow and solute transport experiments, in horizontal packed soil columns, to estimate the parameters that govern water flow and solute transport. The derived parameters are then used to predict water infiltration and solute migration in a repacked soil wedge. Horizontal columns packed with Red Ferrosol were used in a nitrate diffusion experiment to estimate either three or six parameters of the van Genuchten–Mualem equation while keeping residual and saturated water content, and saturated hydraulic conductivity fixed to independently measured values. These parameters were calculated using the inverse optimisation routines in Hydrus 1D. Nitrate concentrations measured along the horizontal soil columns were used to independently determine the Langmuir adsorption isotherm. The soil hydraulic properties described by the van Genuchten–Mualem equation, and the NO3– adsorption isotherm, were then used to predict water and NO3– distributions from a point-source in two 3D flow scenarios. The use of horizontal columns of repacked soil and inverse modelling to quantify the soil water retention curve was found to be a simple and effective method for determining soil hydraulic properties of Red Ferrosols. These generated parameters supported subsequent testing of interactive flow and reactive transport processes under dynamic flow conditions

    Evidence that Differences in Fructosamine-3-Kinase Activity May be Associated with the Glycation Gap in Human Diabetes

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    The phenomenon of a discrepancy between glycated haemoglobin levels and other indicators of average glycaemia may be due to many factors but can be measured as the glycation gap (GGap). This GGap is associated with differences in complications in patients with diabetes and may possibly be explained by dissimilarities in deglycation in turn leading to altered production of Advanced Glycation End (AGE) products. We hypothesised that variations in the level of the deglycating enzyme Fructosamine-3-kinase (FN3K) might be associated with the GGap. We measured erythrocyte FN3K concentrations and enzyme activity in a population dichotomised for a large positive or negative GGap. FN3K protein was higher and we found a striking 3-fold greater activity (323%) at any given FN3K protein level in the erythrocytes of the negative compared with positive GGap groups. This was associated with lower AGE levels in the negative GGap group (79%), lower pro-inflammatory adipokines (Leptin/Adiponectin ratio) (73%) and much lower pro-thrombotic PAI-1 levels (19%). We conclude that FN3K may play a key role in the GGap and thus diabetes complications such that FN3K may be potential predictor of the risk of diabetes complications. Pharmacological modifications of its activity may provide a novel approach to their prevention

    Using a knowledge exchange event to assess study participants’ attitudes to research in a rapidly evolving research context

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    Grant information: DJP, IJD and AMM are supported by Wellcome Trust Grant 104036. IJD, DJP, JPB and AMM, IB, EJK and SFW are supported by MRC Mental Health Data Pathfinder Grant MC_PC_17209. AMM and SML are supported by MRC Grant MC_PC_MR/R01910X/1. AMM is supported by MRC Grant MR/S035818/1. Theirworld Edinburgh Birth Cohort is funded by the charity Theirworld (www.theirworld.org), and is undertaken in the MRC Centre for Reproductive Health, which is funded by MRC Centre Grant (G1002033). CB and DJP are supported by Health Data Research UK, an initiative funded by UK Research and Innovation, Department of Health and Social Care (England) and the devolved administrations, and leading medical research charities.Peer reviewedPublisher PD

    Tale proteins bind to both active and inactive chromatin

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    TALE (transcription activator-like effector) proteins can be tailored to bind to any DNA sequence of choice and thus are of immense utility for genome editing and the specific delivery of transcription activators. However, to perform these functions, they need to occupy their sites in chromatin. In the present study, we have systematically assessed TALE binding to chromatin substrates and find that in vitro TALEs bind to their target site on nucleosomes at the more accessible entry/exit sites, but not at the nucleosome dyad. We show further that in vivo TALEs bind to transcriptionally repressed chromatin and that transcription increases binding by only 2-fold. These data therefore imply that TALEs are likely to bind to their target in vivo even at inactive loci

    Soil respiratory quotient determined via barometric process separation combined with nitrogen-15 labeling

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    The barometric process separation (BaPS) and Âč⁔N dilution techniques were used to determine gross nitrification rates on the same soil cores from an old grassland soil. The BaPS-technique separates the O₂ consumption into that from nitrification and that from soil organic matter (SOM) respiration. The most sensitive parameter for the calculations via the BaPS technique is the respiratory quotient (RQ = ∆CO₂/∆O₂) for SOM turnover (RQSOM). Combining both methods (BaPS–Âč⁔N ) allowed the determination of the RQSOM. The RQ value determined in such a way is adjusted for the influence of nitrification and denitrification, which are both characterized by totally different RQ values. The results for the grassland soil showed that 6 to 10% of O₂ was consumed by nitrification when incubated at 20°C and 0.49 g H₂O g⁻Âč soil. A set of BaPS measurements with the same soil at various temperature and moisture contents showed that up to 49% of the total O₂ consumption was due to nitrification. The calculated RQSOM values via the BaPS–Âč⁔N technique presented here are more closely associated with the overall SOM turnover than the usual net RQ reported in the literature. Furthermore, the RQSOM value provides an overall indication of the decomposability and chemical characteristics of the respired organic material. Hence, it has the potential to serve as a single state index for SOM quality and therefore be a useful index for SOM turnover models based on substrate quality

    The Maia detector array and x-ray fluorescence imaging system: Locating rare precious metal phases in complex samples

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    X-ray fluorescence images acquired using the Maia large solid-angle detector array and integrated real-time processor on the X-ray Fluorescence Microscopy (XFM) beamline at the Australian Synchrotron capture fine detail in complex natural samples with images beyond 100M pixels. Quantitative methods permit real-time display of deconvoluted element images and for the acquisition of large area XFM images and 3D datasets for fluorescence tomography and chemical state (XANES) imaging. This paper outlines the Maia system and analytical methods and describes the use of the large detector array, with a wide range of X-ray take-off angles, to provide sensitivity to the depth of features, which is used to provide an imaging depth contrast and to determine the depth of rare precious metal particles in complex geological samples. © 2013 SPIE

    Defects in the acid phosphatase ACPT cause recessive hypoplastic amelogenesis imperfecta

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    We identified two homozygous missense variants (c.428C>T, p.(T143M) and c.746C>T, p.(P249L)) in ACPT, the gene encoding Acid Phosphatase, Testicular, which segregate with hypoplastic Amelogenesis imperfecta (AI) in two unrelated families. ACPT is reported to play a role in odontoblast differentiation and mineralisation by supplying phosphate during dentine formation. Analysis by computerised tomography and scanning electron microscopy of a primary molar tooth from an individual homozygous for the c.746C>T variant, revealed an enamel layer that was hypoplastic but mineralised with prismatic architecture. These findings implicate variants in ACPT as a cause of early failure of amelogenesis during the secretory phase

    Discarded livers tested by normothermic machine perfusion in the VITTAL trial:Secondary end points and 5-year outcomes

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    Normothermic machine perfusion (NMP) enables pretransplant assessment of high-risk donor livers. The VITTAL trial demonstrated that 71% of the currently discarded organs could be transplanted with 100% 90-day patient and graft survivals. Here, we report secondary end points and 5-year outcomes of this prospective, open-label, phase 2 adaptive single-arm study. The patient and graft survivals at 60 months were 82% and 72%, respectively. Four patients lost their graft due to nonanastomotic biliary strictures, one caused by hepatic artery thrombosis in a liver donated following brain death, and 3 in elderly livers donated after circulatory death (DCD), which all clinically manifested within 6 months after transplantation. There were no late graft losses for other reasons. All the 4 patients who died during the study follow-up had functioning grafts. Nonanastomotic biliary strictures developed in donated after circulatory death livers that failed to produce bile with pH &gt;7.65 and bicarbonate levels &gt;25 mmol/L. Histological assessment in these livers revealed high bile duct injury scores characterized by arterial medial necrosis. The quality of life at 6 months significantly improved in all but 4 patients suffering from nonanastomotic biliary strictures. This first report of long-term outcomes of high-risk livers assessed by normothermic machine perfusion demonstrated excellent 5-year survival without adverse effects in all organs functioning beyond 1 year (ClinicalTrials.gov number NCT02740608).</p

    Development of a Core Outcome Set for effectiveness trials aimed at optimising prescribing in older adults in care homes

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    Background: Prescribing medicines for older adults in care homes is known to be sub-optimal. Whilst trials testing interventions to optimise prescribing in this setting have been published, heterogeneity in outcome reporting has hindered comparison of interventions, thus limiting evidence synthesis. The aim of this study was to develop a core outcome set (COS), a list of outcomes which should be measured and reported, as a minimum, for all effectiveness trials involving optimising prescribing in care homes. The COS was developed as part of the Care Homes Independent Pharmacist Prescribing Study (CHIPPS). Methods: A long-list of outcomes was identified through a review of published literature and stakeholder input. Outcomes were reviewed and refined prior to entering a two-round online Delphi exercise and then distributed via a web link to the CHIPPS Management Team, a multidisciplinary team including pharmacists, doctors and Patient Public Involvement representatives (amongst others), who comprised the Delphi panel. The Delphi panellists (n = 19) rated the importance of outcomes on a 9-point Likert scale from 1 (not important) to 9 (critically important). Consensus for an outcome being included in the COS was defined as ≄70% participants scoring 7–9 and <15% scoring 1–3. Exclusion was defined as ≄70% scoring 1–3 and <15% 7–9. Individual and group scores were fed back to participants alongside the second questionnaire round, which included outcomes for which no consensus had been achieved. Results: A long-list of 63 potential outcomes was identified. Refinement of this long-list of outcomes resulted in 29 outcomes, which were included in the Delphi questionnaire (round 1). Following both rounds of the Delphi exercise, 13 outcomes (organised into seven overarching domains: medication appropriateness, adverse drug events, prescribing errors, falls, quality of life, all-cause mortality and admissions to hospital (and associated costs)) met the criteria for inclusion in the final COS. Conclusions: We have developed a COS for effectiveness trials aimed at optimising prescribing in older adults in care homes using robust methodology. Widespread adoption of this COS will facilitate evidence synthesis between trials. Future work should focus on evaluating appropriate tools for these key outcomes to further reduce heterogeneity in outcome measurement in this context
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