Ultra-compact radio sources: angular-size/redshift data

A compilation of angular-size/redshift data for ultra-compact radio sources is presented, which data derive from a 2.29 GHz VLBI survey undertaken by Preston et al. The sample has formed the basis of a number of investigations, which attempt to determine cosmological parameters from the angular-size/redshift diagram. Full details of the sample are not in the public domain, which omission is rectified here

Effects of the New Cooperative Medical Scheme on village doctor’s prescribing behaviour in Shandong Province

Objective: To assess the effects of China’s new community health insurance, the New Cooperative Medical Scheme (NCMS), on village doctors’ prescribing behaviour. NCMS began in 2003. Method, In 2005 we conducted a quasi-experimental case-control study in Shandong Province, and collected information from 2,271 patient visits in 30 village health stations. Results, NCMS has adversely influenced prescribing behaviour of village doctors. Average number of drugs prescribed, percentage of prescriptions containing antibiotics, number of antibiotics per prescription, percentage of patients given injections, and average per prescription cost were consistently higher in NCMS village health stations than non-NCMS. Within NCMS villages, prescribing behaviour towards insured patients was significantly different to the uninsured. Conclusion, Over-prescribing is common in villages with and without health insurance, with grave concerns for service quality and drug-use safety. Policy implications are NCMS should be redesigned to exert more influence on health providers, with incentives for cost containment and service quality. Stricter regulatory environment for prescriptions is necessary to counter irrational drug-use and ensure people’s access to effective care at reasonable cost.

MDMP: Managed Data Message Passing

MDMP is a new parallel programming approach that aims to provide users with an easy way to add parallelism to programs, optimise the message passing costs of traditional scientific simulation algorithms, and enable existing MPI-based parallel programs to be optimised and extended without requiring the whole code to be re-written from scratch. MDMP utilises a directives based approach to enable users to specify what communications should take place in the code, and then implements those communications for the user in an optimal manner using both the information provided by the user and data collected from instrumenting the code and gathering information on the data to be communicated. This work will present the basic concepts and functionality of MDMP and discuss the performance that can be achieved using our prototype implementation of MDMP on some model scientific simulation applications.Comment: Submitted to SC13, 10 pages, 5 figure

DAOS as HPC Storage: Exploring Interfaces

This work in progress paper outlines research looking at the performance impact of using different storage interfaces to access the high performance object store DAOS. We demonstrate that using DAOS through a FUSE based filesystem interface can provide high performance, but there are impacts when choosing what I/O library or interface to utilises, with HDF5 exhibiting the highest impact. However, this varied depending on what type of I/O operations were undertaken

Optimised hybrid parallelisation of a CFD code on Many Core architectures

COSA is a novel CFD system based on the compressible Navier-Stokes model for unsteady aerodynamics and aeroelasticity of fixed structures, rotary wings and turbomachinery blades. It includes a steady, time domain, and harmonic balance flow solver. COSA has primarily been parallelised using MPI, but there is also a hybrid parallelisation that adds OpenMP functionality to the MPI parallelisation to enable larger number of cores to be utilised for a given simulation as the MPI parallelisation is limited to the number of geometric partitions (or blocks) in the simulation, or to exploit multi-threaded hardware where appropriate. This paper outlines the work undertaken to optimise these two parallelisation strategies, improving the efficiency of both and therefore reducing the computational time required to compute simulations. We also analyse the power consumption of the code on a range of leading HPC systems to further understand the performance of the code.Comment: Submitted to the SC13 conference, 10 pages with 8 figure

Coupling a radial model of the Darcy-Forchheimer equation with a regional groundwater model to simulate drawdown at supply boreholes

Assessing the short and long-term risks to a groundwater source is a critical part of water resource management. In the UK, public water supply companies apply the term Deployable Output (DO) to describe the yield of a groundwater source under drought conditions. DO is constrained by the physical properties of an aquifer and operational factors such as licence conditions, water quality, and pumping and treatment capacity. A robust assessment of groundwater DO should be informed by numerical modeling. This requires the groundwater level in a supply borehole to be accurately simulated within its regional hydrogeological context. A 3D radial flow model of the Darcy-Forchheimer equation is presented for simulating drawdown at a borehole. The Darcy-Forchheimer Radial Flow Model (DFRFM) represents linear and non-linear flows around the borehole; confined and unconfined conditions; vertical heterogeneity in the aquifer and borehole storage. The DFRFM is coupled with a regional groundwater model which represents the large-scale groundwater system, including lateral and vertical aquifer heterogeneity, rivers, and spatially varying recharge. The model has been applied to a supply borehole located in the dual permeability Chalk aquifer, which forms the principal aquifer in the UK and provides 40-70% of the total public water supply in southern and eastern England. The application demonstrates the potential for the coupled model to be used to inform DO assessments and to assess the long-term risk to sources under climate change scenarios

Emissions and energy efficiency on large-scale high performance computing facilities: ARCHER2 UK national supercomputing service case study

Large supercomputing facilities are critical to research in many areas that impact on decisions such as how to address the current climate emergency. For example, climate modelling, renewable energy facility design and new battery technologies. However, these systems themselves are a source of large amounts of emissions due to the embodied emissions associated with their construction, transport, and decommissioning; and the power consumption associated with running the facility. Recently, the UK National Supercomputing Service, ARCHER2, has been analysing the impact of the facility in terms of energy and emissions. Based on this work, we have made changes to the operation of the service that give a cumulative saving of more than 20% in power draw of the computational resources with all application benchmarks showing reduced power to solution. In this paper, we describe our analysis and the changes made to the operation of the service to improve its energy efficiency, and thereby reduce its climate impacts

Mold diseases of chickens and turkeys

Cover title.Includes bibliographical references

Vegetation dieback as a proxy for temperature within a wet pyroclastic density current: A novel experiment and observations from the 6th of August 2012 Tongariro eruption

The 6th of August 2012 eruption of Te Maari (Mt Tongariro, New Zealand) generated wet pyroclastic density currents (PDCs) which caused widespread dieback of vegetation (singed, brown foliage) in their path. An absence of significant charcoal formation suggests that PDC temperatures were mostly below 250 °C. Textural evidence for liquid water being present in the matrices during emplacement (vesicles) suggests that temperatures were b100 °C. We determined a probable minimum PDC temperature using an experiment replicating the critical temperatures required to induce foliar browning in seven species affected by the eruption. In locations where all species exhibited browned foliage (or were defoliated), temperatures were probably ≥64 °C assuming a PDC duration of 60 s. In the more distal areas, where only the most susceptible species were browned while others remained healthy and unaffected, temperatures were probably around 51–58 °C. These results have relevance to volcanic hazard mitigation and risk assessment, especially on the popular Tongariro Alpine Crossing