1,435 research outputs found

    As national politicians drag their feet, cities are taking the lead in meeting national low carbon ambitions

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    It is cities, not national governments, that are increasingly taking the lead in pursuing lower carbon growth. Ed Clarke summarises research by the Centre for Cities that highlights the innovative and practical ways that cities are tackling environmental and economic challenges

    Model Checking - My 27-Year Quest to Overcome the State Explosion Problem

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    Model Checking is an automatic verification technique for state-transition systems that are finite=state or that have finite-state abstractions. In the early 1980 s in a series of joint papers with my graduate students E.A. Emerson and A.P. Sistla, we proposed that Model Checking could be used for verifying concurrent systems and gave algorithms for this purpose. At roughly the same time, Joseph Sifakis and his student J.P. Queille at the University of Grenoble independently developed a similar technique. Model Checking has been used successfully to reason about computer hardware and communication protocols and is beginning to be used for verifying computer software. Specifications are written in temporal logic, which is particularly valuable for expressing concurrency properties. An intelligent, exhaustive search is used to determine if the specification is true or not. If the specification is not true, the Model Checker will produce a counterexample execution trace that shows why the specification does not hold. This feature is extremely useful for finding obscure errors in complex systems. The main disadvantage of Model Checking is the state-explosion problem, which can occur if the system under verification has many processes or complex data structures. Although the state-explosion problem is inevitable in worst case, over the past 27 years considerable progress has been made on the problem for certain classes of state-transition systems that occur often in practice. In this talk, I will describe what Model Checking is, how it works, and the main techniques that have been developed for combating the state explosion problem

    How to protect your new-born from neonatal death: Infant feeding and medical practices in the Gambia

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    Since the 1990s, the reduction of under-five child-mortality has been a priority for the WHO (Millennium Development Goal 4). In the last two decades, the greatest reduction has occurred in children older than 1 month, while neonatal mortality (the first 28 days of life) has declined more slowly. Neonatal deaths, estimated at approximately 4 million annually, now account for more than 40% of deaths worldwide. Bacterial infections are the leading cause of neonatal deaths. Although risk factors for community and hospital based infections potentially leading to neonatal sepsis are well researched, local people's childcare practices in the neonatal phase are poorly understood by clinicians and biomedical researchers. This paper is based on ethnographic research on neonatal caring practices in rural Gambia. We show that many practices centre on protecting the newborn from sicknesses that are believed to be caused by spirits and other supernatural inflictions. Other caring and nourishing practices are performed to enhance the baby's physical, cognitive and moral development making him/her a full member of the community

    Compression stockings for preventing deep vein thrombosis (DVT) in airline passengers

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    Background Air travel might increase the risk of deep vein thrombosis (DVT). It has been suggested that wearing compression stockings might reduce this risk. This is an update of the review first published in 2006. Objectives To assess the effects of wearing compression stockings versus not wearing them for preventing DVT in people travelling on flights lasting at least four hours. Search methods The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL and AMED databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 1 April 2020. We also checked the bibliographies of relevant studies and reviews identified by the search to check for any additional trials. Selection criteria Randomised trials of compression stockings versus no stockings in passengers on flights lasting at least four hours. Trials in which passengers wore a stocking on one leg but not the other, or those comparing stockings and another intervention were also eligible. Data collection and analysis Two review authors independently selected trials for inclusion and extracted data. We sought additional information from trialists where necessary. Main results One new study that fulfilled the inclusion criteria was identified for this update. Twelve randomised trials (n = 2918) were included in this review: ten (n = 2833) compared wearing graduated compression stockings on both legs versus not wearing them; one trial (n = 50) compared wearing graduated compression tights versus not wearing them; and one trial (n = 35) compared wearing a graduated compression stocking on one leg for the outbound flight and on the other leg on the return flight. Eight trials included people judged to be at low or medium risk of developing DVT (n = 1598) and two included high‐risk participants (n = 1273). All flights had a duration of more than five hours. Fifty of 2637 participants with follow‐up data available in the trials of wearing compression stockings on both legs had a symptomless DVT; three wore stockings, 47 did not (odds ratio (OR) 0.10, 95% confidence interval (CI) 0.04 to 0.25, P Authors' conclusions There is high‐certainty evidence that airline passengers similar to those in this review can expect a substantial reduction in the incidence of symptomless DVT and low‐certainty evidence that leg oedema is reduced if they wear compression stockings. The certainty of the evidence was limited by the way that oedema was measured. There is moderate‐certainty evidence that superficial vein thrombosis may be reduced if passengers wear compression stockings. We cannot assess the effect of wearing stockings on death, pulmonary embolism or symptomatic DVT because no such events occurred in these trials. Randomised trials to assess these outcomes would need to include a very large number of people

    The FRII Broad Line Seyfert 1 Galaxy: PKSJ 1037-2705

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    In this article, we demonstrate that PKSJ 1037-2705 has a weak accretion flow luminosity, well below the Seyfert1/QSO dividing line, weak broad emission lines (BELs) and moderately powerful FRII extended radio emission. It is one of the few documented examples of a broad-line object in which the time averaged jet kinetic luminosity, Qˉ\bar{Q}, is larger than the total thermal luminosity (IR to X-ray) of the accretion flow, LbolL_{bol}. The blazar nucleus dominates the optical and near ultraviolet emission and is a strong source of hard X-rays. The strong blazar emission indicates that the relativistic radio jet is presently active. The implication is that even weakly accreting AGN can create powerful jets. Kinetically dominated (Qˉ>Lbol\bar{Q}>L_{bol}) broad-line objects provide important constraints on the relationship between the accretion flow and the jet production mechanism.Comment: To appear in ApJ November 1, 2008, v687n1 issu

    Viewpoint: vaccine inequity in the spotlight.

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    Viewpoint. No abstract available

    One filter, one sample and the N- and O-glyco(proteo)me: towards a system to study disorders of protein glycosylation. : Toward a System to Study Disorders of Protein Glycosylation

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    A method has been developed for release/isolation of O-glycans from glycoproteins in whole cell lysates for mass spectrometric analysis. Cells are lysed in SDS, which is then exchanged for urea and ammonium bicarbonate in a centrifugal filter, before treating with NH4OH to release O-glycans. Following centrifugation, O-glycans are recovered in the filtrate. Sonication achieves O-glycan release in 1 h. Combining the established protocol for filter-aided N-glycan separation, here optimized for enhanced PNGase F efficiency, with the developed O-glycan release method allows analysis of both N- and O-glycans from one sample, in the same filter unit, from 0.5 to 1 million cells. The method is compatible with subsequent analysis of the residual protein by liquid chromatography-mass spectrometry (LC-MS) after glycan release. The medium throughput approach is amenable to analysis of biological replicates, offering a simple way to assess the often subtle changes to glycan profiles accompanying differentiation and disease progression, in a statistically robust way

    Systematic Investigation of the Permeability of Androgen Receptor PROTACs

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    Bifunctional molecules known as PROTACs simultaneously bind an E3 ligase and a protein of interest to direct ubiquitination and clearance of that protein, and they have emerged in the past decade as an exciting new paradigm in drug discovery. In order to investigate the permeability and properties of these large molecules, we synthesized two panels of PROTAC molecules, constructed from a range of protein-target ligands, linkers, and E3 ligase ligands. The androgen receptor, which is a well-studied protein in the PROTAC field was used as a model system. The physicochemical properties and permeability of PROTACs are discussed

    Safety and efficacy of 2% chlorhexidine gluconate aqueous versus 2% chlorhexidine gluconate in 70% isopropyl alcohol for skin disinfection prior to percutaneous central venous catheter insertion in preterm neonates:The ARCTIC randomised-controlled feasibility trial protocol

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    Introduction Catheter-related sepsis is one of the most dangerous complications of neonatal intensive care and is associated with significant morbidity and mortality. Use of catheter-care € bundles' has reduced the incidence of catheter-related sepsis, although individual components have not been well studied. Better evidence is needed to guide selection of the most appropriate antiseptic solution for skin disinfection in preterm neonates. This study will inform the feasibility and design of the first randomised controlled trial to examine the safety and efficacy of alcohol-based versus aqueous-based chlorhexidine antiseptic formulations for skin disinfection prior to percutaneous central venous catheterisation in preterm neonates. The antiseptics to be compared are 2% chlorhexidine gluconate (CHG) aqueous and 2% CHG in 70% isopropyl alcohol. Methods and analysis The Antiseptic Randomised Controlled Trial for Insertion of Catheters (ARCTIC) is a two-centre randomised-controlled feasibility trial. At least 100 preterm infants born at <34 weeks' gestation and due to undergo percutaneous insertion of a central venous catheter will be randomly allocated to receive prior skin disinfection with one of the two antiseptic solutions. Outcomes include: i) recruitment and retention rates; ii) completeness of data collection; iii) numbers of enrolled infants meeting case definitions for definite catheter-related sepsis, catheter-associated sepsis and catheter colonisation and iv) safety outcomes of skin morbidity scores recorded daily from catheter insertion until 48 hours post removal. The key feasibility metrics will be reported as proportions with 95% CIs. Estimated prevalence of catheter colonisation will allow calculation of sample size for the large-scale trial. The data will inform whether it will be feasible to progress to a large-scale trial. Ethics and dissemination ARCTIC has been approved by the National Health Service Health Research Authority National Research Ethics Service Committee East of England (Cambridge South) (IRAS ID 163868), was adopted onto the National Institute of Health Research Clinical Research Network portfolio (CPMS ID 19899) and is registered with an International Standard Randomised Control Trials Number (ISRCTN: 82571474; Pre-results) and European Clinical Trials Database number 2015-000874-36. Dissemination plans include presentations at scientific conferences, scientific publications and sharing of the findings with parents via the support of Bliss baby charity
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