5,171 research outputs found
More security or less insecurity
We depart from the conventional quest for ‘Completely Secure Systems’ and ask ‘How can we be more Secure’. We draw heavily from the evolution of the Theory of Justice and the arguments against the institutional approach to Justice. Central to our argument is the identification of redressable insecurity, or weak links. Our contention is that secure systems engineering is not really about building perfectly secure systems but about redressing manifest insecurities.Final Accepted Versio
Discriminating active from latent tuberculosis in patients presenting to community clinics.
BACKGROUND: Because of the high global prevalence of latent TB infection (LTBI), a key challenge in endemic settings is distinguishing patients with active TB from patients with overlapping clinical symptoms without active TB but with co-existing LTBI. Current methods are insufficiently accurate. Plasma proteomic fingerprinting can resolve this difficulty by providing a molecular snapshot defining disease state that can be used to develop point-of-care diagnostics. METHODS: Plasma and clinical data were obtained prospectively from patients attending community TB clinics in Peru and from household contacts. Plasma was subjected to high-throughput proteomic profiling by mass spectrometry. Statistical pattern recognition methods were used to define mass spectral patterns that distinguished patients with active TB from symptomatic controls with or without LTBI. RESULTS: 156 patients with active TB and 110 symptomatic controls (patients with respiratory symptoms without active TB) were investigated. Active TB patients were distinguishable from undifferentiated symptomatic controls with accuracy of 87% (sensitivity 84%, specificity 90%), from symptomatic controls with LTBI (accuracy of 87%, sensitivity 89%, specificity 82%) and from symptomatic controls without LTBI (accuracy 90%, sensitivity 90%, specificity 92%). CONCLUSIONS: We show that active TB can be distinguished accurately from LTBI in symptomatic clinic attenders using a plasma proteomic fingerprint. Translation of biomarkers derived from this study into a robust and affordable point-of-care format will have significant implications for recognition and control of active TB in high prevalence settings
DNMTs are required for delayed genome instability caused by radiation
This is an open-access article licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License. The article may be redistributed, reproduced, and reused for non-commercial purposes, provided the original source is properly cited - Copyright @ 2012 Landes Bioscience.The ability of ionizing radiation to initiate genomic instability has been harnessed in the clinic where the localized delivery of controlled doses of radiation is used to induce cell death in tumor cells. Though very effective as a therapy, tumor relapse can occur in vivo and its appearance has been attributed to the radio-resistance of cells with stem cell-like features. The molecular mechanisms underlying these phenomena are unclear but there is evidence suggesting an inverse correlation between radiation-induced genomic instability and global hypomethylation. To further investigate the relationship between DNA hypomethylation, radiosensitivity and genomic stability in stem-like cells we have studied mouse embryonic stem cells containing differing levels of DNA methylation due to the presence or absence of DNA methyltransferases. Unexpectedly, we found that global levels of methylation do not determine radiosensitivity. In particular, radiation-induced delayed genomic instability was observed at the Hprt gene locus only in wild-type cells. Furthermore, absence of Dnmt1 resulted in a 10-fold increase in de novo Hprt mutation rate, which was unaltered by radiation. Our data indicate that functional DNMTs are required for radiation-induced genomic instability, and that individual DNMTs play distinct roles in genome stability. We propose that DNMTS may contribute to the acquirement of radio-resistance in stem-like cells.This study is funded by NOTE, BBSRC and the Royal Society Dorothy Hodgkin Research Fellowship
Multi-mode Propagation in 2D filters and Metamaterials
Meta-materials are characterised using a modal technique for the analysis of 2N- port two dimensional filter networks. It will be shown that in general, all such networks support N modes of propagation each with different propagation constants unless as with the TEM multi-wire transmission line, the inductance matrix is the inverse of the capacitance matrix. Furthermore a simple equivalent circuit for these 2N port networks is derived, enabling complete network analysis for any combination of modal excitations. An explicit formula is derived for the propagation constants of a quasi lowpass filter. This demonstrates that there are always N modes even when the transverse network is infinite in extent
Whitehead's varnish nasal pack
Whitehead's varnish is a little known but excellent nasal packing agent. We review available literature on the historical aspects and clinical use of Whitehead's varnish. Our personal experience with Whitehead's varnish is described, and we strongly recommend its use
Common Representation of Information Flows for Dynamic Coalitions
We propose a formal foundation for reasoning about access control policies
within a Dynamic Coalition, defining an abstraction over existing access
control models and providing mechanisms for translation of those models into
information-flow domain. The abstracted information-flow domain model, called a
Common Representation, can then be used for defining a way to control the
evolution of Dynamic Coalitions with respect to information flow
The future of farming: the value of ecosystem services in conventional and organic arable land. An experimental approach.
In the current work, a novel, experimental ‘bottom-up’ approach is used to quantify the economic value of ecosystem services (ES) associated with highly modified arable landscapes in Canterbury, New Zealand. First, the role of land management practices in the maintenance and enhancement of ES in agricultural land was investigated by quantifying the economic value of ES at the field level under organic and conventional arable systems. This quantification was based on an experimental approach in contrast with the earlier value transfer methods. Total annual economic value of ES in organic fields ranged from US 19,420 ha⁻¹ yr⁻¹ and that of conventional fields from US 14,570 ha⁻¹ yr⁻¹. The non-market value of ES in organic fields ranged from US 5240 ha⁻¹ yr⁻¹. The range of non-market values of ES in conventional fields was US 332 million and US 192 million and US 65 million and that of conventional area was US $35 million annually. This study demonstrated that arable farming provides a range of ES which can be measured using field experiments based on ecological principles by incorporating a ‘bottom-up’ approach. The work also showed that conventional New Zealand arable farming practices can severely reduce the financial contribution of some of these services in agriculture whereas organic agriculture practices enhance their economic value
Introduction : screen Londons
Our aim, in editing the ‘London Issue’ of this journal, is to contribute to a conversation between scholars of British cinema and television, London historians and scholars of the cinematic city. In 2007, introducing the themed issue on ‘Space and Place in British Cinema and Television’, Steve Chibnall and Julian Petley observed that it would have been possible to fill the whole journal with essays about the representation of London. This issue does just that, responding to the increased interest in cinematic and, to a lesser extent, televisual, Londons, while also demonstrating the continuing fertility of the paradigms of ‘space and place’ for scholars of the moving image1. It includes a wide range of approaches to the topic of London on screen, with varying attention to British institutions of the moving image – such as Channel Four or the British Board of Film Classification – as well as to concepts such as genre, narration and memory. As a whole, the issue, through its juxtapositions of method and approach, shows something of the complexity of encounters between the terms ‘London’, ‘cinema’ and ‘television’ within British film and television studies
Anomalous origin of the left coronary artery from the pulmonary artery: case report and review
Anomalous origin of the left coronary artery from the pulmonary artery is a rare congenital condition that proves to be fatal in most individuals during childhood due to significant left ventricular ischaemia. However, there are case reports of individuals surviving into adulthood that have varying presenting symptoms. We report a case of a young male, who presented to our cardiology clinic with typical ischaemic cardiac pain, with no established risk factors, and was found to have anomalous origin of the left coronary artery from the pulmonary artery that was subsequently surgically corrected
Quality of Life in Chronic Pancreatitis is Determined by Constant Pain, Disability/Unemployment, Current Smoking, and Associated Co-Morbidities
OBJECTIVES: Chronic pancreatitis (CP) has a profound independent effect on quality of life (QOL). Our aim was to identify factors that impact the QOL in CP patients. METHODS: We used data on 1,024 CP patients enrolled in the three NAPS2 studies. Information on demographics, risk factors, co-morbidities, disease phenotype, and treatments was obtained from responses to structured questionnaires. Physical and mental component summary (PCS and MCS, respectively) scores generated using responses to the Short Form-12 (SF-12) survey were used to assess QOL at enrollment. Multivariable linear regression models determined independent predictors of QOL. RESULTS: Mean PCS and MCS scores were 36.7+/-11.7 and 42.4+/-12.2, respectively. Significant (P \u3c 0.05) negative impact on PCS scores in multivariable analyses was noted owing to constant mild-moderate pain with episodes of severe pain or constant severe pain (10 points), constant mild-moderate pain (5.2), pain-related disability/unemployment (5.1), current smoking (2.9 points), and medical co-morbidities. Significant (P \u3c 0.05) negative impact on MCS scores was related to constant pain irrespective of severity (6.8-6.9 points), current smoking (3.9 points), and pain-related disability/unemployment (2.4 points). In women, disability/unemployment resulted in an additional 3.7 point reduction in MCS score. Final multivariable models explained 27% and 18% of the variance in PCS and MCS scores, respectively. Etiology, disease duration, pancreatic morphology, diabetes, exocrine insufficiency, and prior endotherapy/pancreatic surgery had no significant independent effect on QOL. CONCLUSIONS: Constant pain, pain-related disability/unemployment, current smoking, and concurrent co-morbidities significantly affect the QOL in CP. Further research is needed to identify factors impacting QOL not explained by our analyses
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