Despite promising steps towards the elimination of hepatitis C virus (HCV) in the UK, several indicators provide a cause for concern for future disease burden. We aimed to improve understanding of geographical variation in HCV-related severe liver disease and historic risk factor prevalence among clinic attendees in England and Scotland. We used metadata from 3829 HCV-positive patients consecutively enrolled into HCV Research UK from 48 hospital centres in England and Scotland during 2012–2014. Employing mixed-effects statistical modelling, several independent risk factors were identified: age 46–59 y (ORadj 3.06) and ≥60 y (ORadj 5.64) relative to <46 y, male relative to female sex (ORadj 1.58), high BMI (ORadj 1.73) and obesity (ORadj 2.81) relative to normal BMI, diabetes relative to no diabetes (ORadj 2.75), infection with HCV genotype (GT)-3 relative to GT-1 (ORadj 1.75), route of infection through blood products relative to injecting drug use (ORadj 1.40), and lower odds were associated with black ethnicity (ORadj 0.31) relative to white ethnicity. A small proportion of unexplained variation was attributed to differences between hospital centres and local health authorities. Our study provides a baseline measure of historic risk factor prevalence and potential geographical variation in healthcare provision, to support ongoing monitoring of HCV-related disease burden and the design of risk prevention measures.

Glen’s flow law is a well-established general law for steady-state glacier ice deformation, and many laboratory tests and field measurements have been undertaken which have shown the generality of the law to be correct. In Nature, ice deformation is the response of the glacier/ice sheet to the applied self-weight stress of the ice mass (i.e. ice thickness, gravity and ice density) which produces a stress gradient within the ice column. Detailed experimental analyses of ice samples in the laboratory have until now only been undertaken using uniform stress fields in uniaxial or triaxial tests. Obviously the best method for investigating ice in the laboratory would be if stress gradients similar to those found in Nature could be replicated. In the following paper we describe the physical modelling of two (laboratory-prepared) isotropic, polycrystalline ice models (0.75 × 0.25 × 0.18 m) at enhanced gravity levels (80g) in a geotechnical beam centrifuge. Steel plate was placed on top of the ice model, replicating an overburden of approximately 36 m of ice (at 80g). Thus we were able to model the deformation of the lower 14 m of an ice mass approximately 50 m thick. Models are confined laterally by the Perspex strongbox walls, preventing lateral extension within the sample during testing. Models are unconfined on their downslope ends, rendering longitudinal stresses negligible. Deformation can therefore be treated as simple shear. Samples are instrumented with displacement markers and thermocouples. Values for A and n in the flow law derived from the experiments are reasonable and indicate the potential of this method for ice-deformation studies.

Obsidian hydration dating of volcanic events had been compared with ages of the same events determined by the 14C and K — Ar methods at several localities. The localities, ranging in age from 1200 to over 1 million yr, include Newberry Craters, Oregon; Coso Hot Springs, California; Salton Sea, California; Yellowstone National Park, Wyoming; and Mineral Range, Utah. In most cases the agreement is quite good. A number of factors including volcanic glass composition and exposuretemperature history must be known in order to relate hydration thickness to age. The effect of composition can be determined from chemical analysis or the refractive index of the glass. Exposure-temperature history requires a number of considerations enumerated in this paper.