273 research outputs found
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The role of change agents and stakeholders in the organisational transformation of the electricity industry
This development paper looks at the organisational transformation that is ongoing within the supply part of the electricity network, to meet the changing demands through the growth in adoption of electric vehicles, domestic heat pumps and increased supply from renewable energy sources.
The paper will explore the observations and findings from the involvement of the Open University in an innovation project within a Distribution Network Operator. The focus is to compare the differences between the comparatively easy technical transformation and the harder cultural change, and how change agents and stakeholders influence this process
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Exploring the role of intermediaries in smart grid developments
Smart grid pilot projects have been initiated in a number of locations across the UK. Innovations considered in these projects include various technologies such as smart meters and electrical energy storage devices, as well as novel institutional arrangements which form the basis of commercial Demand Side Response (DSR) initiatives. This paper reports research into DSR using multiple case studies from Low Carbon Network Fund projects in the UK. The role of Aggregator companies in DSR is reported, their role of a key intermediary analysed and conceptualised using the Accessibility, Mobility and Receptivity (AMR) framework
Genome-Wide Mapping of Susceptibility to Coronary Artery Disease Identifies a Novel Replicated Locus on Chromosome 17
Coronary artery disease (CAD) is a leading cause of death world-wide, and most cases have a complex, multifactorial aetiology that includes a substantial heritable component. Identification of new genes involved in CAD may inform pathogenesis and provide new therapeutic targets. The PROCARDIS study recruited 2,658 affected sibling pairs (ASPs) with onset of CAD before age 66 y from four European countries to map susceptibility loci for CAD. ASPs were defined as having CAD phenotype if both had CAD, or myocardial infarction (MI) phenotype if both had a MI. In a first study, involving a genome-wide linkage screen, tentative loci were mapped to Chromosomes 3 and 11 with the CAD phenotype (1,464 ASPs), and to Chromosome 17 with the MI phenotype (739 ASPs). In a second study, these loci were examined with a dense panel of grid-tightening markers in an independent set of families (1,194 CAD and 344 MI ASPs). This replication study showed a significant result on Chromosome 17 (MI phenotype; p = 0.009 after adjustment for three independent replication tests). An exclusion analysis suggests that further genes of effect size λ(sib) > 1.24 are unlikely to exist in these populations of European ancestry. To our knowledge, this is the first genome-wide linkage analysis to map, and replicate, a CAD locus. The region on Chromosome 17 provides a compelling target within which to identify novel genes underlying CAD. Understanding the genetic aetiology of CAD may lead to novel preventative and/or therapeutic strategies
Governing effective and legitimate smart grid developments
Smart grids which use Information and Communication Technologies to augment energy network management have been developed in several locations including London and Stockholm. Common rationales for smart grids include: de-carbonising energy supply, maintaining security of supply and promoting affordability. However, beyond these general abstractions, smart grids seem to exhibit considerable diversity in terms of their characteristics and rationales for development. Thus, while the term smart grid may imply abstract notions of what smart grids are and might do, they are developed in response to local contingencies and diverse. In this paper we therefore explore the governance processes through which smart grids are constructed. The paper suggests that standardising smart grids through definitions and best practices that fix both problems and solutions should be avoided. Rather governance processes should be promoted in which local contingencies can be articulated and more legitimate smart grids developed in response to these
Pain control after total knee arthroplasty: a randomized trial comparing local infiltration anesthesia and continuous femoral block
Local infiltration analgesia (LIA) is a new multimodal wound infiltration method. It
has attracted growing interest in recent years and is widely used all over the world for
treating postoperative pain after knee and hip arthroplasty. This method is based on
systematic infiltration of a mixture of ropivacaine, a long acting local anesthetic,
ketorolac, a cyclooxygenase inhibitor (NSAID), and adrenalin around all structures
subject to surgical trauma inknee and hip arthroplasty.
Two patient cohorts of 40 patients scheduled for elective total knee arthroplasty
(TKA) and 15 patients scheduled for total hip arthroplasty (THA) contributed to the
work presented in this thesis. In a randomized trial the efficacy of LIA in TKA with
regard to pain at rest and upon movement was compared to femoral block. Both
methods result in a high quality pain relief and similar morphine consumption, but
fewer patients in the LIA group reported pain of 7/10 on any occasion during the 24 h
monitoring period (paper I).
In the same patient cohort the maximal total plasma concentration of ropivacaine was
below the established toxic threshold for most patients although a few reached
potentially toxic concentrations of 1.4-1.7 mg/L. The time to maximal detected
plasma concentration was around 4-6 h after release of tourniquet in TKA (paper II).
All patients in the THA cohort were subjected to the routine LIA protocol. In these
patients both the total and unbound plasma concentration of ropivacaine was
determined. The concentration was below the established toxic threshold. As
ropivacaine binds to a-1 acid glycoprotein(AAG) we assessed the possibility that
increased AAG may decrease the unbound concentration of ropivacaine. A40 %
increase in AAG was detected during the first 24 h after surgery, however the
fraction of unbound ropivacaine remained the same. There was a trend towards
increased C max of ropivacaine with increasing age and decreasing creatinine
clearance but the statistical power was too low to draw any conclusion (paper III).
Administration of 30mg ketorolac according to the LIA protocol both in TKA and
THA resulted in a similar Cmax as previously reported after 10 mg intramuscular
ketorolac (paper II, paper IV). Neither age, nor body weight or BMI, nor creatinine
clearance, correlates to maximal ketorolac plasma concentration or total exposure to
ketorolac (AUC) (paper IV).
In conclusion, LIA provides good postoperative analgesia which is similar to femoral
block after total knee arthroplasty. The plasma concentration of ropivacaine seems to
be below toxic levels in most TKA patients. The unbound plasma concentration of
ropivcaine in THA seems to be below the toxic level.
The use of ketorolac in LIA may not be safer than other routes of administration, and
similar restrictions should be applied in patients at risk of developing side effects
Hundreds of variants clustered in genomic loci and biological pathways affect human height
Most common human traits and diseases have a polygenic pattern of inheritance: DNA sequence variants at many genetic loci influence the phenotype. Genome-wide association (GWA) studies have identified more than 600 variants associated with human traits, but these typically explain small fractions of phenotypic variation, raising questions about the use of further studies. Here, using 183,727 individuals, we show that hundreds of genetic variants, in at least 180 loci, influence adult height, a highly heritable and classic polygenic trait. The large number of loci reveals patterns with important implications for genetic studies of common human diseases and traits. First, the 180 loci are not random, but instead are enriched for genes that are connected in biological pathways (P = 0.016) and that underlie skeletal growth defects (P < 0.001). Second, the likely causal gene is often located near the most strongly associated variant: in 13 of 21 loci containing a known skeletal growth gene, that gene was closest to the associated variant. Third, at least 19 loci have multiple independently associated variants, suggesting that allelic heterogeneity is a frequent feature of polygenic traits, that comprehensive explorations of already-discovered loci should discover additional variants and that an appreciable fraction of associated loci may have been identified. Fourth, associated variants are enriched for likely functional effects on genes, being over-represented among variants that alter amino-acid structure of proteins and expression levels of nearby genes. Our data explain approximately 10% of the phenotypic variation in height, and we estimate that unidentified common variants of similar effect sizes would increase this figure to approximately 16% of phenotypic variation (approximately 20% of heritable variation). Although additional approaches are needed to dissect the genetic architecture of polygenic human traits fully, our findings indicate that GWA studies can identify large numbers of loci that implicate biologically relevant genes and pathways.
Phagocytosis of Streptococcus pyogenes by all-trans retinoic acid-differentiated HL-60 cells: roles of azurophilic granules and NADPH oxidase.
BACKGROUND: New experimental approaches to the study of the neutrophil phagosome and bacterial killing prompted a reassessment of the usefulness of all-trans retinoic acid (ATRA)-differentiated HL-60 cells as a neutrophil model. HL-60 cells are special in that they possess azurophilic granules while lacking the specific granules with their associated oxidase components. The resulting inability to mount an effective intracellular respiratory burst makes these cells more dependent on other mechanisms when killing internalized bacteria. METHODOLOGY/PRINCIPAL FINDINGS: In this work phagocytosis and phagosome-related responses of ATRA-differentiated HL-60 cells were compared to those earlier described in human neutrophils. We show that intracellular survival of wild-type S. pyogenes bacteria in HL-60 cells is accompanied by inhibition of azurophilic granule-phagosome fusion. A mutant S. pyogenes bacterium, deficient in M-protein expression, is, on the other hand, rapidly killed in phagosomes that avidly fuse with azurophilic granules. CONCLUSIONS/SIGNIFICANCE: The current data extend our previous findings by showing that a system lacking in oxidase involvement also indicates a link between inhibition of azurophilic granule fusion and the intraphagosomal fate of S. pyogenes bacteria. We propose that differentiated HL-60 cells can be a useful tool to study certain aspects of neutrophil phagosome maturation, such as azurophilic granule fusion
The Thermal Beta-Function in Yang-Mills Theory
Previous calculations of the thermal beta-function in a hot Yang--Mills gas
at the one--loop level have exposed problems with the gauge dependence and with
the sign, which is opposite to what one would expect for asymptotic freedom. We
show that inclusion of higher--loop effects through a static Braaten--Pisarski
resummation is necessary to consistently obtain the leading term, but alters
the results only quantitatively. The sign, in particular, remains the same. We
also explore, by a crude parameterization, the effects a (non--perturbative)
magnetic mass may have on these results.Comment: 16pp,latex + epsf.sty, Nordita-94/36
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