458 research outputs found

    Introduction:navigating secrecy in security research

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    This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book offers a rich set of analyses of the challenges of secrecy in security research, and sets out practical ways to navigate, encircle and work with secrecy. It aims to offer not just a conceptual reflection on the dynamics of secrecy, but also practical, hands-on methodological guidance for qualitative fieldwork in the security domain. The book describes new ways of conceptualising secrecy in relation to fieldwork, by understanding secrecy as more than a barrier to be overcome. It shows how secrecy itself can be made productive to the analysis: mapping secrecies and sensitivities in the field can itself be revealing; navigating obfuscation is co-productive of research design and data. The book focuses on reconceptualising secrecy as a complex practice and mode of power

    Construction of probabilistic event trees for eruption forecasting at Sinabung volcano, Indonesia 2013-14

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    Eruptions of Sinabung volcano, Indonesia have been ongoing since 2013. Since that time, the character of eruptions has changed, from phreatic to phreatomagmatic to magmatic explosive eruptions, and from production of a lava dome that collapsed to a subsequent thick lava flow that slowly ceased to be active, and later, to a new lava dome. As the eruption progressed, event trees were constructed to forecast eruptive behavior six times, with forecast windows that ranged from 2. weeks to 1. year: November 7-10, December 12-14, and December 27, 2013; and January 9-10, May 13, and October 7, 2014. These event trees were successful in helping to frame the forecast scenarios, to collate current monitoring information, and to document outstanding questions and unknowns. The highest probability forecasts closely matched outcomes of eruption size (including extrusion of the first dome), production of pyroclastic density currents, and pyroclastic density current runout distances. Events assigned low probabilities also occurred, including total collapse of the lava dome in January 2014 and production of a small blast pyroclastic density current in February 2014

    Volcano dome dynamics at Mount St. Helens:Deformation and intermittent subsidence monitored by seismicity and camera imagery pixel offsets

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    The surface deformation field measured at volcanic domes provides insights into the effects of magmatic processes, gravity-and gas-driven processes, and the development and distribution of internal dome structures. Here we study short-term dome deformation associated with earthquakes at Mount St. Helens, recorded by a permanent optical camera and seismic monitoring network. We use Digital Image Correlation (DIC) to compute the displacement field between successive images and compare the results to the occurrence and characteristics of seismic events during a 6 week period of dome growth in 2006. The results reveal that dome growth at Mount St. Helens was repeatedly interrupted by short-term meter-scale downward displacements at the dome surface, which were associated in time with low-frequency, large-magnitude seismic events followed by a tremor-like signal. The tremor was only recorded by the seismic stations closest to the dome. We find a correlation between the magnitudes of the camera-derived displacements and the spectral amplitudes of the associated tremor. We use the DIC results from two cameras and a high-resolution topographic model to derive full 3-D displacement maps, which reveals internal dome structures and the effect of the seismic activity on daily surface velocities. We postulate that the tremor is recording the gravity-driven response of the upper dome due to mechanical collapse or depressurization and fault-controlled slumping. Our results highlight the different scales and structural expressions during growth and disintegration of lava domes and the relationships between seismic and deformation signals

    Omega-3 fatty acids correlate with gut microbiome diversity and production of N-carbamylglutamate in middle aged and elderly women

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    Omega-3 fatty acids may influence human physiological parameters in part by affecting the gut microbiome. The aim of this study was to investigate the links between omega-3 fatty acids, gut microbiome diversity and composition and faecal metabolomic profiles in middle aged and elderly women. We analysed data from 876 twins with 16S microbiome data and DHA, total omega-3, and other circulating fatty acids. Estimated food intake of omega-3 fatty acids were obtained from food frequency questionnaires. Both total omega-3and DHA serum levels were significantly correlated with microbiome alpha diversity (Shannon index) after adjusting for confounders (DHA Beta(SE) = 0.13(0.04), P = 0.0006 total omega-3: 0.13(0.04), P = 0.001). These associations remained significant after adjusting for dietary fibre intake. We found even stronger associations between DHA and 38 operational taxonomic units (OTUs), the strongest ones being with OTUs from the Lachnospiraceae family (Beta(SE) = 0.13(0.03), P = 8 × 10-7). Some of the associations with gut bacterial OTUs appear to be mediated by the abundance of the faecal metabolite N-carbamylglutamate. Our data indicate a link between omega-3 circulating levels/intake and microbiome composition independent of dietary fibre intake, particularly with bacteria of the Lachnospiraceae family. These data suggest the potential use of omega-3 supplementation to improve the microbiome composition

    Metabolomic Profiling of Long-Term Weight Change:Role of Oxidative Stress and Urate Levels in Weight Gain

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    OBJECTIVE: To investigate the association between long-term weight change and blood metabolites. METHODS: Change in BMI over 8.6 ± 3.79 years was assessed in 3,176 females from the TwinsUK cohort (age range: 18.3-79.6, baseline BMI: 25.11 ± 4.35) measured for 280 metabolites at follow-up. Statistically significant metabolites (adjusting for covariates) were included in a multivariable least absolute shrinkage and selection operator (LASSO) model. Findings were replicated in the Cooperative Health Research in the Region of Augsburg (KORA) study (n = 1,760; age range: 25-70, baseline BMI: 27.72 ± 4.53). The study examined whether the metabolites identified could prospectively predict weight change in KORA and in the Prostate, Lung, Colorectal, and Ovarian Cancer (PLCO) study (n = 471; age range: 55-74, baseline BMI: 27.24 ± 5.37). RESULTS: Thirty metabolites were significantly associated with change in BMI per year in TwinsUK using Bonferroni correction. Four were independently associated with weight change in the multivariable LASSO model and replicated in KORA: namely, urate (meta-analysis β [95% CI] = 0.05 [0.040 to 0.063]; P = 1.37 × 10-19 ), gamma-glutamyl valine (β [95% CI] = 0.06 [0.046 to 0.070]; P = 1.23 × 10-20 ), butyrylcarnitine (β [95% CI] = 0.04 [0.028 to 0.051]; P = 6.72 × 10-12 ), and 3-phenylpropionate (β [95% CI] = -0.03 [-0.041 to -0.019]; P = 9.8 × 10-8 ), all involved in oxidative stress. Higher levels of urate at baseline were associated with weight gain in KORA and PLCO. CONCLUSIONS: Metabolites linked to higher oxidative stress are associated with increased long-term weight gain

    Intramedullary nail fixation versus locking plate fixation for adults with a fracture of the distal tibia : the UK FixDT RCT

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    Background The best treatment for fractures of the distal tibia remains controversial. Most of these fractures require surgical fixation, but the outcomes are unpredictable and complications are common. Objectives To assess disability, quality of life, complications and resource use in patients treated with intramedullary (IM) nail fixation versus locking plate fixation in the 12 months following a fracture of the distal tibia. Design This was a multicentre randomised trial. Setting The trial was conducted in 28 UK acute trauma centres from April 2013 to final follow-up in February 2017. Participants In total, 321 adult patients were recruited. Participants were excluded if they had open fractures, fractures involving the ankle joint, contraindication to nailing or inability to complete questionnaires. Interventions IM nail fixation (n = 161), in which a metal rod is inserted into the hollow centre of the tibia, versus locking plate fixation (n = 160), in which a plate is attached to the surface of the tibia with fixed-angle screws. Main outcome measures The primary outcome measure was the Disability Rating Index (DRI) score, which ranges from 0 points (no disability) to 100 points (complete disability), at 6 months with a minimum clinically important difference of 8 points. The DRI score was also collected at 3 and 12 months. The secondary outcomes were the Olerud–Molander Ankle Score (OMAS), quality of life as measured using EuroQol-5 Dimensions (EQ-5D), complications such as infection, and further surgery. Resource use was collected to inform the health economic evaluation. Results Participants had a mean age of 45 years (standard deviation 16.2 years), were predominantly male (61%, 197/321) and had experienced traumatic injury after a fall (69%, 223/321). There was no statistically significant difference in DRI score at 6 months [IM nail fixation group, mean 29.8 points, 95% confidence interval (CI) 26.1 to 33.7 points; locking plate group, mean 33.8 points, 95% CI 29.7 to 37.9 points; adjusted difference, 4.0 points, 95% CI –1.0 to 9.0 points; p = 0.11]. There was a statistically significant difference in DRI score at 3 months in favour of IM nail fixation (IM nail fixation group, mean 44.2 points, 95% CI 40.8 to 47.6 points; locking plate group, mean 52.6 points, 95% CI 49.3 to 55.9 points; adjusted difference 8.8 points, 95% CI 4.3 to 13.2 points; p < 0.001), but not at 12 months (IM nail fixation group, mean 23.1 points, 95% CI 18.9 to 27.2 points; locking plate group, 24.0 points, 95% CI 19.7 to 28.3 points; adjusted difference 1.9 points, 95% CI –3.2 to 6.9 points; p = 0.47). Secondary outcomes showed the same pattern, including a statistically significant difference in mean OMAS and EQ-5D scores at 3 and 6 months in favour of IM nail fixation. There were no statistically significant differences in complications, including the number of postoperative infections (13% in the locking plate group and 9% in the IM nail fixation group). Further surgery was more common in the locking plate group (12% in locking plate group and 8% in IM nail fixation group at 12 months). The economic evaluation showed that IM nail fixation provided a slightly higher quality of life in the 12 months after injury and at lower cost and, therefore, it was cost-effective compared with locking plate fixation. The probability of cost-effectiveness for IM nail fixation exceeded 90%, regardless of the value of the cost-effectiveness threshold. Limitations As wound dressings after surgery are clearly visible, it was not possible to blind the patients to their treatment allocation. This evidence does not apply to intra-articular (pilon) fractures of the distal tibia. Conclusions Among adults with an acute fracture of the distal tibia who were randomised to IM nail fixation or locking plate fixation, there were similar disability ratings at 6 months. However, recovery across all outcomes was faster in the IM nail fixation group and costs were lower
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