144 research outputs found
Cutaneous Ulcerations as the Presenting Sign of Acute Aortic Occlusion
This is a report of a case of acute aortic occlusion (AAO) in a 46-year-old woman who presented with confluent and coalescing punched-out ulcerations on the bilateral medial buttocks and abdominal ulcerations. This case highlights how AAO, although rare, should be considered in patients with cardiovascular risk factors presenting with acute lower extremity pain and new-onset cutaneous ulcerations of the perineum and/or abdomen
ElAM: A computer program for the analysis and representation of anisotropic elastic properties
Copyright © 2010 Elsevier. NOTICE: this is the author’s version of a work that was accepted for publication in Computer Physics Communications. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Computer Physics Communications, Volume 181, Issue 12 (2010), DOI: 10.1016/j.cpc.2010.08.033The continuum theory of elasticity has been used for more than a century and has applications in many fields of science and engineering. It is very robust, well understood and mathematically elegant. In the isotropic case elastic properties are easily represented, but for non-isotropic materials, even in the simple cubic symmetry, it can be difficult to visualise how properties such as Young's modulus or Poisson's ratio vary with stress/strain orientation. The ElAM (Elastic Anisotropy Measures) code carries out the required tensorial operations (inversion, rotation, diagonalisation) and creates 3D models of an elastic property's anisotropy. It can also produce 2D cuts in any given plane, compute averages following diverse schemes and query a database of elastic constants to support meta-analyses.
Program summary
Program title: ElAM1.0
Catalogue identifier: AEHB_v1_0
Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEHB_v1_0.html
Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland
Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html
No. of lines in distributed program, including test data, etc.: 43 848
No. of bytes in distributed program, including test data, etc.: 2 498 882
Distribution format: tar.gz
Programming language: Fortran90
Computer: Any
Operating system: Linux, Windows (XP, Vista)
RAM: Depends chiefly on the size of the arrays representing elastic properties in 3D
Classification: 7.7
Nature of problem: Representation of elastic moduli and ratios, and of wave velocities, in 3D; automatic discovery of unusual elastic properties.
Solution method: Stiffness matrix (6×6)(6×6) inversion and conversion to compliance tensor (3×3×3×3)(3×3×3×3), tensor rotation, dynamic matrix diagonalisation, simple optimisation, postscript and VRML output preparation.
Running time: Dependent on angular accuracy and size of elastic constant database (from a few seconds to a few hours). The tests provided take from a few seconds for test0 to approximately 1 hour for test4
Simulation of greenhouse gases following land-use change to bioenergy crops using the ECOSSE model : a comparison between site measurements and model predictions
This work contributes to the ELUM (Ecosystem Land Use Modelling & Soil Carbon GHG Flux Trial) project, which was commissioned and funded by the Energy Technologies Institute (ETI). We acknowledge the E-OBS data set from the EU-FP6 project ENSEMBLES (http://ensembles-eu.metoffice.com) and the data providers in the ECA&D project (http://www.ecad.eu).Peer reviewedPublisher PD
Brillouin scattering study on the single-crystal elastic properties of natrolite and analcime zeolites
Copyright © 2005 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Journal of Applied Physics 98 (2005) and may be found at http://link.aip.org/link/?jap/98/053508The Brillouin light-scattering technique was used to investigate the single-crystal elastic properties of two aluminosilicate zeolites, natrolite (NAT) and analcime (ANA), at ambient conditions. An inversion of the acoustic velocity data results in the full set of elastic stiffness moduli (Cij's) for both materials. From the single-crystal moduli the aggregate adiabatic bulk moduli (Ks), shear moduli (G), and Poisson's ratios (v) were found to be Ks=48.5(1.0) GPa, G=31.6(1.0) GPa, and v =0.232(5) for NAT, and Ks=59.8(1.2) GPa, G=32.1(1.0) GPa, and v=0.272(5) for ANA (Voigt-Reuss-Hill averages). The bulk and shear moduli of both zeolites are relatively low compared with those of densely packed aluminosilicates, reflecting an open framework structure of (Al,SiO4) tetrahedra which is easily deformed by bending the Si–O–Al angles. As expected for a less dense crystal, NAT is softer and more compressible than ANA. An evaluation of the directional Young's moduli shows that the compressibility of NAT is nearly uniform along the [100] and [010] axes, while [001] is stiffer, in agreement with previous compression studies. We do not find experimental evidence of negative Poisson's ratios for NAT zeolites as predicted by recent theoretical calculations
A well-conserved Plasmodium falciparum var gene shows an unusual stage-specific transcript pattern
The var multicopy gene family encodes Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) variant antigens, which, through their ability to adhere to a variety of host receptors, are thought to be important virulence factors. The predominant expression of a single cytoadherent PfEMP1 type on an infected red blood cell, and the switching between different PfEMP1 types to evade host protective antibody responses, are processes thought to be controlled at the transcriptional level. Contradictory data have been published on the timing of var gene transcription. Reverse transcription-polymerase chain reaction (RT-PCR) data suggested that transcription of the predominant var gene occurs in the later (pigmented trophozoite) stages, whereas Northern blot data indicated such transcripts only in early (ring) stages. We investigated this discrepancy by Northern blot, with probes covering a diverse var gene repertoire. We confirm that almost all var transcript types were detected only in ring stages. However, one type, the well-conserved varCSA transcript, was present constitutively in different laboratory parasites and does not appear to undergo antigenic variation. Although varCSA has been shown to encode a chondroitin sulphate A (CSA)-binding PfEMP1, we find that the presence of full-length varCSA transcripts does not correlate with the CSA-binding phenotype
Patterns of gene recombination shape var gene repertoires in Plasmodium falciparum: comparisons of geographically diverse isolates
BACKGROUND: Var genes encode a family of virulence factors known as PfEMP1 (Plasmodium falciparum erythrocyte membrane protein 1) which are responsible for both antigenic variation and cytoadherence of infected erythrocytes. Although these molecules play a central role in malaria pathogenesis, the mechanisms generating variant antigen diversification are poorly understood. To investigate var gene evolution, we compared the variant antigen repertoires from three geographically diverse parasite isolates: the 3D7 genome reference isolate; the recently sequenced HB3 isolate; and the IT4/25/5 (IT4) parasite isolate which retains the capacity to cytoadhere in vitro and in vivo. RESULTS: These comparisons revealed that only two var genes (var1csa and var2csa) are conserved in all three isolates and one var gene (Type 3 var) has homologs in IT4 and 3D7. While the remaining 50 plus genes in each isolate are highly divergent most can be classified into the three previously defined major groups (A, B, and C) on the basis of 5' flanking sequence and chromosome location. Repertoire-wide sequence comparisons suggest that the conserved homologs are evolving separately from other var genes and that genes in group A have diverged from other groups. CONCLUSION: These findings support the existence of a var gene recombination hierarchy that restricts recombination possibilities and has a central role in the functional and immunological adaptation of var genes
The MidPIC study : midwives’ knowledge, perspectives and learning needs regarding preconception and interconception care
Preconception and interconception care improves health outcomes of women and communities. Little is known about how prepared and willing Australian midwives are to provide preconception and interconception care. The aim of this study was to explore midwives’ knowledge, perspectives and learning needs, and barriers and enablers to delivering preconception and interconception care. We conducted a cross-sectional exploratory study of midwives working in any Australian maternity setting. An online survey measured midwives’ self-rated knowledge; education needs and preferences; attitudes towards pre and interconception care; and views on barriers, enablers; and, future service and workforce planning. Quantitative data were analysed descriptively and demographic characteristics (e.g., years of experience, model of care) associated with knowledge and attitudes regarding pre- and interconception care were examined using univariate logistic regression analysis. Qualitative data were captured through open-ended questions and analysed using inductive content analysis. We collected responses from (n = 338) midwives working across all models of care (full survey completion rate 96%). Most participants (n = 290; 85%) rated their overall knowledge about pre and interconception health as excellent, above average or average. Participants with over 11 years of experience were more likely to report above average to excellent knowledge (OR 3.11; 95% CI 1.09, 8.85). Online e-learning was the most preferred format for education on this topic (n = 244; 72%). Most (n = 257; 76%) reported interest in providing pre and interconception care more regularly and that this is within the midwifery scope of practice (n = 292; 87%). Low prioritisation in service planning was the most frequently selected barrier to providing preconception and interconception care, whereas continuity models and hybrid child health settings were reported as enablers of pre and interconception care provision. Findings revealed that midwives are prepared and willing to provide preconception and interconception care. Pre and post registration professional development; service and funding reform; and policy development are critical to enable Australian midwives’ provision of pre and interconception care
Ship-based contributions to global ocean, weather, and climate observing systems
The role ships play in atmospheric, oceanic, and biogeochemical observations is described with a focus on measurements made within 100 m of the ocean surface. Ships include merchant and research vessels, cruise liners and ferries, fishing vessels, coast guard, military, and other government-operated ships, yachts, and a growing fleet of automated surface vessels. The present capabilities of ships to measure essential climate/ocean variables and the requirements from a broad community to address operational, commercial, and scientific needs are described. Following the guidance from the OceanObs'19 organizing committee, the authors provide a vision to expand observations needed from ships to understand and forecast the exchanges across the ocean-atmosphere interface. The vision addresses (1) recruiting vessels to improve both spatial and temporal sampling, (2) conducting multi-variate sampling on ships, (3) raising technology readiness levels of automated shipboard sensors and ship-to-shore data communications, (4) advancing quality evaluation of observations, and (5) developing a unified data management approach for observations and metadata that meets the needs of a diverse user community. Recommendations are made focusing on integrating private and autonomous vessels into the observing system, investing in sensor and communications technology development, developing an integrated data management structure that includes all types of ships, and moving towards a quality evaluation process that will result in a subset of ships being defined as mobile reference ships that will support climate studies. We envision a future where commercial, research, and privately-owned vessels are making multivariate observations using a combination of automated and human-observed measurements. All data and metadata will be documented, tracked, evaluated, distributed, and archived to benefit users of marine data. This vision looks at ships as a holistic network, not a set of disparate commercial, research, and/or third-party activities working in isolation, to bring these communities together for the mutual benefit of all
Impact of a referral management “gateway” on the quality of referral letters; a retrospective time series cross sectional review
Background
Referral management centres (RMC) for elective referrals are designed to facilitate the primary to secondary care referral path, by improving quality of referrals and easing pressures on finite secondary care services, without inadvertently compromising patient care.
This study aimed to evaluate whether the introduction of a RMC which includes triage and feedback improved the quality of elective outpatient referral letters.
Methods
Retrospective, time-series, cross-sectional review involving 47 general practices in one primary care trust (PCT) in South-East England. Comparison of a random sample of referral letters at baseline (n = 301) and after seven months of referral management (n = 280). Letters were assessed for inclusion of four core pieces of information which are used locally to monitor referral quality (blood pressure, body mass index, past medical history, medication history) and against research-based quality criteria for referral letters (provision of clinical information and clarity of reason for referral).
Results
Following introduction of the RMC, the proportion of letters containing each of the core items increased compared to baseline. Statistically significant increases in the recording of ‘past medical history’ (from 71% to 84%, p < 0.001) and ‘medication history’ (78% to 87%, p = 0.006) were observed. Forty four percent of letters met the research-based quality criteria at baseline but there was no significant change in quality of referral letters judged on these criteria across the two time periods.
Conclusion
Introduction of RMC has improved the inclusion of past medical history and medication history in referral letters, but not other measures of quality. In approximately half of letters there remains room for further improvement
Mapping infectious disease hospital surge threats to lessons learnt in Singapore: a systems analysis and development of a framework to inform how to DECIDE on planning and response strategies.
BACKGROUND: Hospital usage and service demand during an Infectious Disease (ID) outbreak can tax the health system in different ways. Herein we conceptualize hospital surge elements, and lessons learnt from such events, to help build appropriately matched responses to future ID surge threats. METHODS: We used the Interpretive Descriptive qualitative approach. Interviews (n = 35) were conducted with governance and public health specialists; hospital based staff; and General Practitioners. Key policy literature in tandem with the interview data were used to iteratively generate a Hospital ID Surge framework. We anchored our narrative account within this framework, which is used to structure our analysis. RESULTS: A spectrum of surge threats from combinations of capacity (for crowding) and capability (for treatment complexity) demands were identified. Starting with the Pyramid scenario, or an influx of high screening rates flooding Emergency Departments, alongside fewer and manageable admissions; the Reverse-Pyramid occurs when few cases are screened and admitted but those that are, are complex; during a 'Black' scenario, the system is overburdened by both crowding and complexity. The Singapore hospital system is highly adapted to crowding, functioning remarkably well at constant near-full capacity in Peacetime and resilient to Endemic surges. We catalogue 26 strategies from lessons learnt relating to staffing, space, supplies and systems, crystalizing institutional memory. The DECIDE model advocates linking these strategies to types of surge threats and offers a step-by-step guide for coordinating outbreak planning and response. CONCLUSIONS: Lack of a shared definition and decision making of surge threats had rendered the procedures somewhat duplicative. This burden was paradoxically exacerbated by a health system that highly prizes planning and forward thinking, but worked largely in silo until an ID crisis hit. Many such lessons can be put into play to further strengthen our current hospital governance and adapted to more diverse settings
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