1,138 research outputs found
Ultrasonic tomographic imaging of defects in industrial materials
Ultrasonic tomography has been fairly widely applied for imaging of inhomogeneities in isotropic materials, particularly in the medical field, however, little success has been made in its application to industrial materials. This is largely due to the complex nature of ultrasonic wave propagation in these anisotropic materials. The three dimensional characteristics of ultrasonic wave propagation in anisotropic materials have been thoroughly studied for single crystals and also studied recently for different composites [1,2,3]. Understanding these characteristics provides the theoretical background for developing appropriate ultrasonic tomographic imaging methods for industrial materials
Remission vs low disease activity: function, quality of life and structural outcomes in the Early Rheumatoid Arthritis Study and Network
Objectives To examine associations between function, quality of life and structural outcomes in patients achieving remission vs low disease activity in early RA. Methods Demographic, clinical and radiographic variables were collected at baseline and then annually from the Early Rheumatoid Arthritis Study (ERAS) and Early Rheumatoid Arthritis Network (ERAN) inception cohorts in routine care from 1986 to 2012. Disease activity was categorized: mean DAS28 score between years 1 and 5: remission [mean remission DAS (mRDAS) <2.6] or low [mean low DAS (mLDAS) 2.6–3.2]; sustained low/remission DAS28 (sLDAS/sRDAS) at years 1 and 2; and sustained Boolean remission (sBR) at years 1 and 2. Changes in HAQ and Short Form 36 Health Survey Questionnaire [SF-36; physical (PCS) and mental (MCS) component score]) and total Sharp van der Heijde (SvdH) scores for each disease activity category were modelled using multi-level models. Covariates included year of onset, age, gender and DMARD use at first visit. Results Of 2701 patients, 562 (21%) were categorized mRDAS, 330 (12%) mLDAS, 279 (10%) sRDAS, 203 (7.5%) sLDAS and 93 (3%) sBR. Patients categorized as mRDAS had increasingly divergent improved HAQ, SF-36 PCS, MCS and total SvdH scores compared with mLDAS (P-values 0.001 to <0.0001, all time points). Patients categorized as sRDAS had better HAQ, SF-36 PCS and MCS scores (P-values 0.05 to <0.0001, all time points) and SvdH scores (P = 0.05, years 3–5) over sLDAS. sBR was associated with better HAQ, and SF-36 PCS and MCS scores over sLDAS (P-values 0.002 to <0.0001, all time points). Conclusion These findings from routine care support ACR/EULAR guidelines that remission is a preferable goal over low disease activity in early RA.Peer reviewedFinal Published versio
Tomographic Reconstruction of Internal Temperature
The development of a sensor to measure internal temperature distributions of hot bodies would significantly improve the productivity and quality of materials processing. The American Iron and Steel Institute (AISI) and the National Bureau of Standards have initiated a joint research program to develop such a sensor for steels capable of generating internal temperature maps with ±10°C accuracy and 20 mm spatial resolution. Numerous applications exist for such a sensor during the processing of steel (and other metals); two of particular importance are in the control of continuous casting and slab reheating1
Quantifying the Erosional Response to Tectonic Forcing: Be10 Catchment Average Erosion Rates from the Taupo Rift, New Zealand.
Conductivity Imaging in Plates Using Current Injection Tomography
The task of reconstructing an unknown distribution of electrical conductivity is widely recognized as a central theoretical problem in eddy-current nondestructive evaluation [1]. Rather than using an eddy-current method, we address this problem using DC injection of current into conductive materials. Experimental methods of the magnetic imaging of injected currents using high-resolution SQUID magnetometers have been described elsewhere [2]. In this paper we describe a tomographic method for using magnetically-imaged, injected currents to reconstruct distributions of electrical conductivity. Much of what we describe should also be applicable to data obtained using uniform colinear eddy currents induced by means of planar sheet inducers [4, 5]
Inflammatory breast carcinoma as a model of accelerated self-metastatic expansion by intravascular growth
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Clinician and patient perspectives on the barriers and facilitators to physical rehabilitation in intensive care: a qualitative interview study
Data availability statement:
No data are available beyond what is reported in this manuscript and the supplemental files due to participant confidentiality requirements.Objectives: The objective of this study is to explore patient, relative/carer and clinician perceptions of barriers to early physical rehabilitation in intensive care units (ICUs) within an associated group of hospitals in the UK and how they can be overcome.
Design: Qualitative study using semi-structured interviews and thematic framework analysis.
Setting: Four ICUs over three hospital sites in London, UK.
Participants: Former ICU patients or their relatives/carers with personal experience of ICU rehabilitation. ICU clinicians, including doctors, nurses, physiotherapists and occupational therapists, involved in the delivery of physical rehabilitation or decisions over its initiation.
Primary and secondary outcomes measures: Views and experiences on the barriers and facilitators to ICU physical rehabilitation.
Results: Interviews were carried out with 11 former patients, 3 family members and 16 clinicians. The themes generated related to: safety and physiological concerns, patient participation and engagement, clinician experience and knowledge, teamwork, equipment and environment and risks and benefits of rehabilitation in intensive care. The overarching theme for overcoming barriers was a change in working model from ICU clinicians having separate responsibilities (a multidisciplinary approach) to one where all parties have a shared aim of providing patient-centred ICU physical rehabilitation (an interdisciplinary approach).
Conclusions: The results have revealed barriers that can be modified to improve rehabilitation delivery in an ICU. Interdisciplinary working could overcome many of these barriers to optimise recovery from critical illness.Clinical Doctoral Research Fellowship, awarded to HRW, (ICA-CDRF-2015-01-026), supported by the National Institute for Health Research (NIHR) and Health Education England. We acknowledge the support of the NIHR Clinical Research Network and infrastructure support for this research was provided by the NIHR Imperial Biomedical Research Centre (BRC). HRW is supported by the NIHR Imperial BRC
Fear and Courage in Children: Two Sides of the Same Coin?
This study further investigated the construct of courage in children. Children aged 8–13 years (n = 51) were interviewed about the most courageous action that they had ever performed during their life, and to retrospectively rate their level of fear and courage experienced during that event. On a separate occasion, children also completed the Courage Measure for Children (CM-C) as an index of children’s general level of personal courage, as well as scales for assessing anxiety symptoms and sensation seeking. Results indicated that almost all children (i.e., 94%) indicated that they had carried out a courageous action at some point during their life, although the levels of fear and courage associated with these acts varied considerably. Further, there was no relation between fear and courage reported for the courageous action, but these variables were significantly correlated with respectively anxiety symptoms and personal courage as indexed by the CM-C. Finally, a significant positive correlation was observed between sensation seeking and personal courage, indicating that children who are more thrill and adventure seeking are generally also more courageous. It is concluded that fear and courage in children are largely unrelated and not just two sides of the same coin. The implications of these results for the etiology and treatment of childhood anxiety problems are discussed
CHERI: A hybrid capability-system architecture for scalable software compartmentalization
CHERI extends a conventional RISC Instruction-
Set Architecture, compiler, and operating system to support
fine-grained, capability-based memory protection to mitigate
memory-related vulnerabilities in C-language TCBs. We describe
how CHERI capabilities can also underpin a hardware-software
object-capability model for application compartmentalization
that can mitigate broader classes of attack. Prototyped as an
extension to the open-source 64-bit BERI RISC FPGA softcore
processor, FreeBSD operating system, and LLVM compiler,
we demonstrate multiple orders-of-magnitude improvement in
scalability, simplified programmability, and resulting tangible
security benefits as compared to compartmentalization based on
pure Memory-Management Unit (MMU) designs. We evaluate
incrementally deployable CHERI-based compartmentalization
using several real-world UNIX libraries and applications.We thank our colleagues Ross Anderson, Ruslan Bukin,
Gregory Chadwick, Steve Hand, Alexandre Joannou, Chris
Kitching, Wojciech Koszek, Bob Laddaga, Patrick Lincoln,
Ilias Marinos, A Theodore Markettos, Ed Maste, Andrew W.
Moore, Alan Mujumdar, Prashanth Mundkur, Colin Rothwell,
Philip Paeps, Jeunese Payne, Hassen Saidi, Howie Shrobe, and
Bjoern Zeeb, our anonymous reviewers, and shepherd Frank
Piessens, for their feedback and assistance. This work is part of
the CTSRD and MRC2 projects sponsored by the Defense Advanced
Research Projects Agency (DARPA) and the Air Force
Research Laboratory (AFRL), under contracts FA8750-10-C-
0237 and FA8750-11-C-0249. The views, opinions, and/or
findings contained in this paper are those of the authors and
should not be interpreted as representing the official views
or policies, either expressed or implied, of the Department
of Defense or the U.S. Government. We acknowledge the EPSRC
REMS Programme Grant [EP/K008528/1], Isaac Newton
Trust, UK Higher Education Innovation Fund (HEIF), Thales
E-Security, and Google, Inc.This is the author accepted manuscript. The final version is available at http://dx.doi.org/10.1109/SP.2015.
Determining Conductivity and Thickness of Continuously Varying Layers on Metals Using Eddy Currents
Modifications to metal surfaces are important for many products; they can improve the interaction of the product with its environment, while retaining the structural properties of the bulk metal. Surface modifications provide properties such as good electrical contact as well as resistance to wear, corrosion and high temperatures. Consequently, it is desirable to develop nondestructive methods for characterizing near-surface properties, such as the electrical conductivity and magnetic permeability. In this paper we present an eddy current method to determine the structure of continuously changing surface layers.</p
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