15,522 research outputs found

    Unstable and elusive superconductors

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    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

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    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

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    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

    Une "Chanson de Roland" gasconne?

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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.

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    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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