61 research outputs found

    TAO: Techniques for algorithm-level obfuscation during high-level synthesis

    Get PDF
    Intellectual Property (IP) theft costs semiconductor design companies billions of dollars every year. Unauthorized IP copies start from reverse engineering the given chip. Existing techniques to protect against IP theft aim to hide the IC's functionality, but focus on manipulating the HDL descriptions. We propose TAO as a comprehensive solution based on high-level synthesis to raise the abstraction level and apply algorithmic obfuscation automatically. TAO includes several transformations that make the component hard to reverse engineer during chip fabrication, while a key is later inserted to unlock the functionality. Finally, this is a promising approach to obfuscate large-scale designs despite the hardware overhead needed to implement the obfuscation

    Vegetation management with fire modifies peatland soil thermal regime

    Get PDF
    Vegetation removal with fire can alter the thermal regime of the land surface, leading to significant changes in biogeochemistry (e.g. carbon cycling) and soil hydrology. In the UK, large expanses of carbon-rich upland environments are managed to encourage increased abundance of red grouse (Lagopus lagopus scotica) by rotational burning of shrub vegetation. To date, though, there has not been any consideration of whether prescribed vegetation burning on peatlands modifies the thermal regime of the soil mass in the years after fire. In this study thermal regime was monitored across 12 burned peatland soil plots over an 18-month period, with the aim of (i) quantifying thermal dynamics between burned plots of different ages (from <2 to 15+years post burning), and (ii) developing statistical models to determine the magnitude of thermal change caused by vegetation management. Compared to plots burned 15+years previously, plots recently burned (<2-4 years) showed higher mean, maximum and range of soil temperatures, and lower minima. Statistical models (generalised least square regression) were developed to predict daily mean and maximum soil temperature in plots burned 15+years prior to the study. These models were then applied to predict temperatures of plots burned 2, 4 and 7 years previously, with significant deviations from predicted temperatures illustrating the magnitude of burn management effects. Temperatures measured in soil plots burned <2 years previously showed significant statistical disturbances from model predictions, reaching+6.2°C for daily mean temperatures and+19.6°C for daily maxima. Soil temperatures in plots burnt 7 years previously were most similar to plots burned 15+years ago indicating the potential for soil temperatures to recover as vegetation regrows. Our findings that prescribed peatland vegetation burning alters soil thermal regime should provide an impetus for further research to understand the consequences of thermal regime change for carbon processing and release, and hydrological processes, in these peatlands

    Whole-genome sequencing reveals host factors underlying critical COVID-19

    Get PDF
    Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2–4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

    Whole-genome sequencing reveals host factors underlying critical COVID-19

    Get PDF
    Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

    Elevated plasma free cortisol concentrations and ratios are associated with increased mortality even in the presence of statin therapy in patients with severe sepsis

    No full text
    Dissociation between plasma-free cortisol and total cortisol profiles exists in critical illness. Data on plasma-free cortisol are based on either calculated values or immunoassay-based measurements. Both have significant limitations. Statins have been advocated as a therapy in sepsis. Whether they impact on plasma cortisol through inhibition of cholesterol synthesis is unclear.In patients enrolled into a randomized trial of statins in sepsis (n = 250), we examined the association of mass spectrometry measured plasma-free cortisol, plasma-free cortisol/plasma total cortisol ratios, and outcome and the impact of concomitant statin therapy on cortisol profiles in 80 steroid naïve patients.Two hundred twenty serial measurements of plasma-free cortisol, plasma total cortisol, and interleukin-6 were collected from 80 patients (43 placebo and 37 statins). Data from 10 volunteers were used as controls.Data are presented as median and interquartile range. Compared with controls, in severe sepsis, baseline plasma total cortisol was elevated two-fold (463 nmol/L [284-742 nmol/L] vs 245 nmol/L [200-299 nmol/L], p < 0.001), plasma-free cortisol 20-fold (75 nmol/L [20-151 nmol/L] vs 5 nmol/L [5-7 nmol/L], p < 0.001), and plasma-free cortisol/plasma total cortisol ratio six-fold (0.15 vs 0.02, p = 0.058). Baseline interleukin-6 was elevated at 121 pg/mL (65-611 pg/mL). In severe sepsis, there were no differences in plasma total cortisol (p = 0.66), plasma-free cortisol (p = 0.77), and interleukin-6 (p = 0.29) between statins and placebo groups. Plasma-free cortisol, plasma total cortisol, and plasma-free cortisol/plasma total cortisol were positively correlated with interleukin-6 (p = 0.0001, p < 0.0004, and p < 0.001, respectively) and day 90 mortality (p = 0.03, p = 0.03, and p = 0.058, respectively). Elevated plasma-free cortisol/plasma total cortisol ratios were associated with increased length of stay (p = 0.04). Baseline plasma-free cortisol, plasma total cortisol, and plasma-free cortisol/plasma total cortisol ratios were higher in nonsurvivors as compared with survivors (174 nmol/L [77-329 nmol/L] vs 57 nmol/L [17-122 nmol/L], p = 0.016; 890 nmol/L [333-1,430 nmol/L] vs 408 nmol/L [269-681 nmol/L], p = 0.035; and 0.19 [0.13-0.29] vs 0.14 [0.07-0.20]; p = 0.054, respectively).In severe sepsis, plasma-free cortisol increase is 10-fold greater than that of plasma total cortisol. Both are similarly associated with inflammatory response and mortality. Elevated plasma-free cortisol/plasma total cortisol ratios were associated with increased length of stay. Statin therapy does not influence the plasma cortisol profiles in patients with severe sepsis

    The impact of subterranean termite activity on water infiltration and topsoil properties in Burkina Faso

    No full text
    Few quantitative experimental studies have been carried out on the influence of subterranean termite activity on the water infiltration capacity of crusted soils in the semi-arid Sahelian region. These studies found increased infiltration rates on soils that were affected by foraging galleries of subterranean termites. In this paper, remarkable results are presented from crusted agricultural fields in the Sanmatenga region in Burkina Faso with clear termite activity compared to reference fields without termite activity. Fine-scale rainfall experiments were carried out and general topsoil (upper 5 cm) characteristics were measured. Infiltration rates were found to be significantly slower on plots affected by subterranean termite activity. These results are contradictory to the findings reported in general literature. On the basis of topsoil property measurements, the reduced infiltration rates cannot be indisputably explained, and we suggest that the main responsible factor for a reduction of infiltration was related to differences in topsoil surface (upper 3 mm) properties. Two hypotheses are formulated in an attempt to explain the reduced water infiltration rates on termite plots
    • …
    corecore