Experiences in the Use of Guided Ultrasonic Waves to Scan Structures

The use of guided ultrasonic waves to rapidly interrogate large structures is a topic that is currently receiving considerable attention. The purpose of this paper, and the companion paper by Alers [1], is to briefly review some past experience that may not be readily available to current researchers since many of the results were not presented in archival publications. The work described in this paper was conducted in the context of exploring applications of electromagnetic-acoustic transducers (EMATs) [2,3] as a part of the NDE effort at the Rockwell International Science Center in the period 1970–1980. In addition to the author, others playing key roles in various parts of this effort included G. A. Alers, R. K. Elsley, C. M. Fortunko, M.W. Mahoney and C. F. Vasile. The companion paper by Alers includes subsequent developments at the private company, Magnasonics, Inc. as well as more recent work at the National Institute of Standards and Technology. Although EMAT’s were used in all of this work as the sensors to excite and detect the guided ultrasonic modes, the basic ideas apply to the use of guided modes excited by any kind of sensor to scan structures

The Elastic Compliance of Imperfect Interfaces: Review and Relationship to Ultrasonic Scattering

When a tensile load is applied to an elastic solid with an imperfect interface containing cracks or voids, the farfield displacement that would occur in the absence of the interface will be increased by localized deformations [1]. This extra extension can be modeled as the response of two half-spaces connected by a distributed spring. The spring stiffness per unit area, K, is a function of the topography of the partially contacting surfaces

A global assessment of the impact of climate change on water scarcity

This paper presents a global scale assessment of the impact of climate change on water scarcity. Patterns of climate change from 21 Global Climate Models (GCMs) under four SRES scenarios are applied to a global hydrological model to estimate water resources across 1339 watersheds. The Water Crowding Index (WCI) and the Water Stress Index (WSI) are used to calculate exposure to increases and decreases in global water scarcity due to climate change. 1.6 (WCI) and 2.4 (WSI) billion people are estimated to be currently living within watersheds exposed to water scarcity. Using the WCI, by 2050 under the A1B scenario, 0.5 to 3.1 billion people are exposed to an increase in water scarcity due to climate change (range across 21 GCMs). This represents a higher upper-estimate than previous assessments because scenarios are constructed from a wider range of GCMs. A substantial proportion of the uncertainty in the global-scale effect of climate change on water scarcity is due to uncertainty in the estimates for South Asia and East Asia. Sensitivity to the WCI and WSI thresholds that define water scarcity can be comparable to the sensitivity to climate change pattern. More of the world will see an increase in exposure to water scarcity than a decrease due to climate change but this is not consistent across all climate change patterns. Additionally, investigation of the effects of a set of prescribed global mean temperature change scenarios show rapid increases in water scarcity due to climate change across many regions of the globe, up to 2°C, followed by stabilisation to 4°C

A case study and critical assessment in calculating power usage effectiveness for a data centre

Metrics commonly used to assess the energy efficiency of data centres are analysed through performing and critiquing a case study calculation of energy efficiency. Specifically, the metric Power Usage Effectiveness (PUE), which has become a de facto standard within the data centre industry, will be assessed. This is achieved by using open source specifications for a data centre in Prineville, Oregon, USA provided by the Open Compute Project launched by the social networking company Facebook. The usefulness of the PUE metric to the IT industry is critically assessed and it is found that whilst it is important for encouraging lower energy consumption in data centres, it does not represent an unambiguous measure of energy efficiency

Study protocol: a randomised controlled trial investigating the effect of exercise training on peripheral blood gene expression in patients with stable angina

Background: Exercise training has been shown to reduce angina and promote collateral vessel development in patients with coronary artery disease. However, the mechanism whereby exercise exerts these beneficial effects is unclear. There has been increasing interest in the use of whole genome peripheral blood gene expression in a wide range of conditions to attempt to identify both novel mechanisms of disease and transcriptional biomarkers. This protocol describes a study in which we will assess the effect of a structured exercise programme on peripheral blood gene expression in patients with stable angina, and correlate this with changes in angina level, anxiety, depression, and exercise capacity. Methods/Design: Sixty patients with stable angina will be recruited and randomised 1: 1 to exercise training or conventional care. Patients randomised to exercise training will attend an exercise physiology laboratory up to three times weekly for supervised aerobic interval training sessions of one hour in total duration. Patients will undergo assessments of angina, anxiety, depression, and peripheral blood gene expression at baseline, after six and twelve weeks of training, and twelve weeks after formal exercise training ceases. Discussion: This study will provide comprehensive data on the effect of exercise training on peripheral blood gene expression in patients with angina. By correlating this with improvement in angina status we will identify candidate peripheral blood transcriptional markers predictive of improvements in angina level in response to exercise training

Results of a randomized, double-blind phase II clinical trial of NY-ESO-1 vaccine with ISCOMATRIX adjuvant versus ISCOMATRIX alone in participants with high-risk resected melanoma.

BACKGROUND: To compare the clinical efficacy of New York Esophageal squamous cell carcinoma-1 (NY-ESO-1) vaccine with ISCOMATRIX adjuvant versus ISCOMATRIX alone in a randomized, double-blind phase II study in participants with fully resected melanoma at high risk of recurrence. METHODS: Participants with resected stage IIc, IIIb, IIIc and IV melanoma expressing NY-ESO-1 were randomized to treatment with three doses of NY-ESO-1/ISCOMATRIX or ISCOMATRIX adjuvant administered intramuscularly at 4-week intervals, followed by a further dose at 6 months. Primary endpoint was the proportion free of relapse at 18 months in the intention-to-treat (ITT) population and two per-protocol populations. Secondary endpoints included relapse-free survival (RFS) and overall survival (OS), safety and NY-ESO-1 immunity. RESULTS: The ITT population comprised 110 participants, with 56 randomized to NY-ESO-1/ISCOMATRIX and 54 to ISCOMATRIX alone. No significant toxicities were observed. There were no differences between the study arms in relapses at 18 months or for median time to relapse; 139 vs 176 days (p=0.296), or relapse rate, 27 (48.2%) vs 26 (48.1%) (HR 0.913; 95% CI 0.402 to 2.231), respectively. RFS and OS were similar between the study arms. Vaccine recipients developed strong positive antibody responses to NY-ESO-1 (p≤0.0001) and NY-ESO-1-specific CD4+ and CD8+ responses. Biopsies following relapse did not demonstrate differences in NY-ESO-1 expression between the study populations although an exploratory study demonstrated reduced (NY-ESO-1)+/Human Leukocyte Antigen (HLA) class I+ double-positive cells in biopsies from vaccine recipients performed on relapse in 19 participants. CONCLUSIONS: The vaccine was well tolerated, however, despite inducing antigen-specific immunity, it did not affect survival endpoints. Immune escape through the downregulation of NY-ESO-1 and/or HLA class I molecules on tumor may have contributed to relapse

The JCMT Legacy Survey of the Gould Belt: Mapping 13CO and C 18O in Orion A

The Gould Belt Legacy Survey will map star-forming regions within 500 pc, using Heterodyne Array Receiver Programme (HARP), Submillimetre Common-User Bolometer Array 2 (SCUBA-2) and Polarimeter 2 (POL-2) on the James Clerk Maxwell Telescope (JCMT). This paper describes HARP observations of the J= 3 → 2 transitions of 13CO and C18O towards Orion A. The 15 arcsec resolution observations cover 5 pc of the Orion filament, including OMC 1 (including BN–KL and Orion bar), OMC 2/3 and OMC 4, and allow a comparative study of the molecular gas properties throughout the star-forming cloud. The filament shows a velocity gradient of ∼1 km s−1 pc−1 between OMC 1, 2 and 3, and high-velocity emission is detected in both isotopologues. The Orion Nebula and Bar have the largest masses and linewidths, and dominate the mass and energetics of the high-velocity material. Compact, spatially resolved emission from CH3CN, 13CH3OH, SO, HCOOCH3, CH3CHO and CH3OCHO is detected towards the Orion Hot Core. The cloud is warm, with a median excitation temperature of ∼24 K; the Orion Bar has the highest excitation temperature gas, at >80 K. The C18O excitation temperature correlates well with the dust temperature (to within 40 per cent). The C18O emission is optically thin, and the 13CO emission is marginally optically thick; despite its high mass, OMC 1 shows the lowest opacities. A virial analysis indicates that Orion A is too massive for thermal or turbulent support, but is consistent with a model of a filamentary cloud that is threaded by helical magnetic fields. The variation of physical conditions across the cloud is reflected in the physical characteristics of the dust cores. We find similar core properties between starless and protostellar cores, but variations in core properties with position in the filament. The OMC 1 cores have the highest velocity dispersions and masses, followed by OMC 2/3 and OMC 4. The differing fragmentation of these cores may explain why OMC 1 has formed clusters of high-mass stars, whereas OMC 4 produces fewer, predominantly low-mass stars