473 research outputs found
Entropic descriptor of a complex behaviour
We propose a new type of entropic descriptor that is able to quantify the
statistical complexity (a measure of complex behaviour) by taking
simultaneously into account the average departures of a system's entropy S from
both its maximum possible value Smax and its minimum possible value Smin. When
these two departures are similar to each other, the statistical complexity is
maximal. We apply the new concept to the variability, over a range of length
scales, of spatial or grey-level pattern arrangements in simple models. The
pertinent results confirm the fact that a highly non-trivial, length-scale
dependence of the entropic descriptor makes it an adequate complexity-measure,
able to distinguish between structurally distinct configurational macrostates
with the same degree of disorder.Comment: 14 pages, 7 figures, extended versio
Enhancing Widening Participation Evaluation through the development of a self-assessment tool for practitioners: Learning from the Standards of Evaluation Practice (Phase 2) project 2017-2019
This is the author accepted manuscript. The final version is available from the Open University via the DOI in this recordThe ultimate goal of widening participation work, that unites policy
makers, practitioners and academics, is to enhance outcomes for
disadvantaged students in HE access, success and outcomes. This article
presents the Office for Students (OfS) commissioned project ‘Understanding
effective evaluation of the impact of outreach interventions on access to
higher education: Phase Two’. This project sought to create a step-change in
robustness of evidence used and evaluation practices. Our 2017-19 project
explored evaluation practices among nine partner organisations drawn from
higher education providers (HEPs) and third sector partners. The initial aim
was to pilot test the Standards of Evidence developed during Phase One
research, to share practices that work and highlight examples of best
practice. As the project developed, a further outcome of the project was
envisaged through ongoing discussions between the OfS, academics, HEPs
and third-sector parties: a self-assessment tool for evaluation practitioners.
This tool provides a framework and guidance which allows practitioners to
map their own evaluation approaches. Through using prompts, the five
dimensions of the tool highlight strengths and weaknesses of evaluation
within five domains (strategic context, programme design, evaluation
design, evaluation design and learning). This new tool is in effect a five point
framework setting guidance about good evaluation practice. It was rolled
out to all HEPs in spring 2019 when providers were invited to return the completed tool and their reflection as part of their Access and Participation
planning.Office for Fair Access (OFFA
Microbial contamination of domiciliary nebulisers and clinical implications in chronic obstructive pulmonary disease.
BACKGROUND AND PURPOSE: Domiciliary nebulisers are widely used in chronic obstructive pulmonary disease (COPD) but nebuliser cleaning practice has not been assessed in patients with COPD who are often elderly and may have severe disease and multiple comorbidities. We aimed to evaluate microbial contamination of home nebulisers used by patients with COPD. METHODS: Random microbiological assessment of domiciliary nebulisers was undertaken together with an enquiry into cleaning practices. We also examined the effectiveness of the trust-wide cleaning instructions in eradicating isolated microorganisms in a laboratory setting. RESULTS: The mean age of patients in this study was 71 (range 40-93) years, and in 68% of patients a large number of significant comorbidities were present. Forty-four nebuliser sets were obtained and 73% were contaminated with microorganisms at >100 colony forming units/plate. Potentially pathogenic bacteria colonised 13 of the 44 nebulisers (30%) and organisms isolated included Pseudomonas aeroginosa, Staphylococcus aureus, multidrug resistant Serratia marcesans, Escherichia coli and multiresistant Klebsiella spp, Enterobacteriaceae and fungus Fusarium oxysporum. Washing of nebuliser masks, chambers and mouthpieces achieved complete eradication of Gram-positive bacterial and fungal flora. Gram-negative organisms were incompletely eradicated, which may be attributed to the presence of biofilms. We also found that in patients with pathogenic organisms cultured on the nebuliser sets, there was a higher probability of occurrence of a COPD exacerbation with a mean number of exacerbations of 3.3 (SD=1) per year in the group in whom pathogens were isolated compared with 1.7 (SD=1.2) exacerbations per year in those whose sets grew non-pathogenic flora (p=0.02). CONCLUSIONS: Nebulisers contaminated with microorganisms are potential reservoirs delivering serious pathogens to the lung. Relationships between nebuliser contamination, clinical infection and exacerbations require further examination, but is a potential concern in elderly patients with COPD with comorbidities who fail to effectively maintain reasonable standards of nebuliser cleanliness
Features of the Extension of a Statistical Measure of Complexity to Continuous Systems
We discuss some aspects of the extension to continuous systems of a
statistical measure of complexity introduced by Lopez-Ruiz, Mancini and Calbet
(LMC) [Phys. Lett. A 209 (1995) 321]. In general, the extension of a magnitude
from the discrete to the continuous case is not a trivial process and requires
some choice. In the present study, several possibilities appear available. One
of them is examined in detail. Some interesting properties desirable for any
magnitude of complexity are discovered on this particular extension.Comment: 22 pages, 0 figure
Inhomogeneity and complexity measures for spatial patterns
In this work we examine two different measures for inhomogeneity and
complexity that are derived from nonextensive considerations a' la Tsallis.
Their performance is then tested on theoretically generated patterns. All
measures are found to exhibit a most sensitive behaviour for Sierpinski
carpets. The procedures here introduced provide us with new, powerful Tsallis'
tools for analysing the inhomogeneity and complexity of spatial patterns.Comment: 15 pages, 7 figures; replaced with published versio
Paraoxonase 2 protein is spatially expressed in the human placenta and selectively reduced in labour
Humans parturition involves interaction of hormonal, neurological, mechanical stretch and inflammatory pathways and the placenta plays a crucial role. The paraoxonases (PONs 1–3) protect against oxidative damage and lipid peroxidation, modulation of endoplasmic reticulum stress and regulation of apoptosis. Nothing is known about the role of PON2 in the placenta and labour. Since PON2 plays a role in oxidative stress and inflammation, both features of labour, we hypothesised that placental PON2 expression would alter during labour. PON2 was examined in placentas obtained from women who delivered by cesarean section and were not in labour and compared to the equivalent zone of placentas obtained from women who delivered vaginally following an uncomplicated labour. Samples were obtained from 12 sites within each placenta: 4 equally spaced apart pieces were sampled from the inner, middle and outer placental regions. PON2 expression was investigated by Western blotting and real time PCR. Two PON2 forms, one at 62 kDa and one at 43 kDa were found in all samples. No difference in protein expression of either isoform was found between the three sites in either the labour or non-labour group. At the middle site there was a highly significant decrease in PON2 expression in the labour group when compared to the non-labour group for both the 62 kDa form (p = 0.02) and the 43 kDa form (p = 0.006). No spatial differences were found within placentas at the mRNA level in either labour or non-labour. There was, paradoxically, an increase in PON2 mRNA in the labour group at the middle site only. This is the first report to describe changes in PON2 in the placenta in labour. The physiological and pathological significance of these remains to be elucidated but since PON2 is anti-inflammatory further studies are warranted to understand its role
Frequency metrology in quantum degenerate helium: Direct measurement of the 2 3S1 - 2 1S0 transition
Precision spectroscopy of simple atomic systems has refined our understanding
of the fundamental laws of quantum physics. In particular, helium spectroscopy
has played a crucial role in describing two-electron interactions, determining
the fine-structure constant and extracting the size of the helium nucleus. Here
we present a measurement of the doubly-forbidden 1557-nanometer transition
connecting the two metastable states of helium (the lowest energy triplet state
2 3S1 and first excited singlet state 2 1S0), for which quantum electrodynamic
and nuclear size effects are very strong. This transition is fourteen orders of
magnitude weaker than the most predominantly measured transition in helium.
Ultracold, sub-microkelvin, fermionic 3He and bosonic 4He atoms are used to
obtain a precision of 8.10^{-12}, providing a stringent test of two-electron
quantum electrodynamic theory and of nuclear few-body theory.Comment: 14 pages, 6 figure
Airbnb and crime in Barcelona (Spain): testing the relationship using a geographically weighted regression
The existence of works proving the possible relationship empirically that Airbnb lodgings could have with crime in Spain is not known. This research analyzes the relationship between Airbnb lodgings and crimes against the properties and people in Barcelona’s neighbourhoods. To achieve this, we use an ordinary least squares regression model and a geographically weighted regression model. The results show a significant and positive relationship between the higher density of Airbnb lodgings and the higher crime rates in the neighbourhoods, especially of patrimonial nature. Divided by type of leased space, the Airbnb homes, in which the guest shares a room with other guests, show a higher relationship with crimes against property and people. The results of the local model show a spatial heterogeneity in all variables used, indicating the need to address non-stationary spatial processes that reveal hidden patterns. However, the only variable that shows statistically significant local variability is the total Airbnb lodgings variable. Finally, we discussed some unexpected results, proposing some future lines of research. © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group, on behalf of Nanjing Normal University
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