15,914 research outputs found
Resilience of Hierarchical Critical Infrastructure Networks
Concern over the resilience of critical infrastructure networks has increased dramatically over the last decade due to a
number of well documented failures and the significant disruption associated with these. This has led to a large body of
research that has adopted graph-theoretic based analysis in order to try and improve our understanding of infrastructure
network resilience. Many studies have asserted that infrastructure networks possess a scale-free topology which is
robust to random failures but sensitive to targeted attacks at highly connected hubs. However, many studies have
ignored that many networks in addition to their topological connectivity may be organised either logically or spatially
in a hierarchical system which may significantly change their response to perturbations. In this paper we explore if
hierarchical network models exhibit significantly different higher-order topological characteristics compared to other
network structures and how this impacts on their resilience to a number of different failure types. This is achieved by
investigating a suite of synthetic networks as well as a suite of ‘real world’ spatial infrastructure networks
Unstable and elusive superconductors
We briefly review earlier and report original experimental results in the
context of metastable or possible superconducting materials. We show that
applied electric field induces conducting state in Copper Chloride (CuCl) whose
characteristics resemble behavior of sliding charge-density-wave(s) (CDW). We
discuss whether the sliding CDW or collective transport of similar ordered
charge phase(s) may account for the problem of "high-temperature
superconductivity" observed in this and other materials, including Cadmium
Sulfide (CdS), metal-ammonia solutions, polymers, amorphous carbon and tungsten
oxides. We also discuss a local superconductivity that occurs at the surface of
graphite and amorphous carbon under deposition of foreign atoms/molecules.Comment: Invited review article published in a special edition on
Superconducting Materials in honor of the 95th birthday year of Ted Geballe,
edited by M. B. Maple, J. Hirsch, and F. Marsigli
An investigation into the relationship between preceding break crops and weed populations in barley crops in organic ley/arable rotations
This report was presented at the UK Organic Research 2002 Conference. The relationship between weed populations and cereal crops following nine organic break crops was investigated in field trials in Warwickshire, Aberdeenshire and Ceredigion in 2001. Weed biodiversity was high on all sites and varied between sites in terms of species present. Severity of weed infestation differed significantly between sites and between cereals following different break crops. The impact of break crop species on the incidence and severity of the weed burden in the following cereal is discussed in relation to the field trials at the three sites
Assessment of the microbial communities associated with white syndrome and brown jelly syndrome in aquarium corals
Bacterial and ciliate assemblages associated with aquarium corals displaying white syndrome (WS) and brown jelly syndrome (BJS) were investigated. Healthy (n = 10) and diseased corals (WS n = 18; BJS n = 3) were analysed for 16S rRNA gene bacterial diversity, total bacterial abundance and vibrio-specific 16S rRNA gene abundance. This was conducted alongside analysis of 18S rRNA gene sequenc-ing targeting ciliates, a group of organisms largely overlooked for their potential as causal agents of coral disease. Despite significant differences between healthy and diseased corals in their 16S rRNA gene bacterial diversity, total bacterial abundance and vibrio-specific rRNA gene abundance, no domi-nant bacterial ribotypes were found consistently within the diseased samples. In contrast, one ciliate morphotype, named Morph 3 in this study (GenBank Accession Numbers JF831358 for the ciliate isolated from WS and JF831359 for the ciliate isolated from BJS) was observed to burrow into and underneath the coral tissues at the disease lesion in both disease types and contained algal endosym-bionts indicative of coral tissue ingestion. This ciliate was observed in larger numbers in BJS compared to WS, giving rise to the characteristic jelly like substance in BJS. Morph 3 varied by only 1 bp over 549 bp from the recently described Morph 1 ciliate (GenBank Accession No. JN626268), which has been shown to be present in field samples of WS and Brown Band Disease (BrB) in the Indo-Pacific. This result indicates a close relationship between these aquarium diseases and those observed in the wild
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Is child weight status correctly reported to parents? Cross-sectional analysis of National Child Measurement Programme data using ethnic-specific BMI adjustments.
BACKGROUND: BMI underestimates and overestimates body fat in children from South Asian and Black ethnic groups, respectively. METHODS: We used cross-sectional NCMP data (2015-17) for 38 270 children in three inner-London local authorities: City & Hackney, Newham and Tower Hamlets (41% South Asian, 18.8% Black): 20 439 4-5 year-olds (48.9% girls) and 17 831 10-11 year-olds (49.1% girls). We estimated the proportion of parents who would have received different information about their child's weight status, and the area-level prevalence of obesity-defined as ≥98th centile-had ethnic-specific BMI adjustments been employed in the English National Child Measurement Programme (NCMP). RESULTS: Had ethnic-specific adjustment been employed, 19.7% (3112/15 830) of parents of children from South Asian backgrounds would have been informed that their child was in a heavier weight category, and 19.1% (1381/7217) of parents of children from Black backgrounds would have been informed that their child was in a lighter weight category. Ethnic-specific adjustment increased obesity prevalence from 7.9% (95% CI: 7.6, 8.3) to 9.1% (8.7, 9.5) amongst 4-5 year-olds and from 17.5% (16.9, 18.1) to 18.8% (18.2, 19.4) amongst 10-11 year-olds. CONCLUSIONS: Ethnic-specific adjustment in the NCMP would ensure equitable categorization of weight status, provide correct information to parents and support local service provision for families
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