735 research outputs found

    Editorial

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    Detection and diversity of a putative novel heterogeneous polymorphic proline-glycine repeat (Pgr) protein in the footrot pathogen Dichelobacter nodosus

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    Dichelobacter nodosus, a Gram-negative anaerobic bacterium, is the essential causative agent of footrot in sheep. Currently, depending on the clinical presentation in the field, footrot is described as benign or virulent; D. nodosus strains have also been classified as benign or virulent, but this designation is not always consistent with clinical disease. The aim of this study was to determine the diversity of the pgr gene, which encodes a putative proline-glycine repeat protein (Pgr). The pgr gene was present in all 100 isolates of D. nodosus that were examined and, based on sequence analysis had two variants, pgrA and pgrB. In pgrA, there were two coding tandem repeat regions, R1 and R2: different strains had variable numbers of repeats within these regions. The R1 and R2 were absent from pgrB. Both variants were present in strains from Australia, Sweden and the UK, however, only pgrB was detected in isolates from Western Australia. The pgrA gene was detected in D. nodosus from tissue samples from two flocks in the UK with virulent footrot and only pgrB from a flock with no virulent or benign footrot for >10 years. Bioinformatic analysis of the putative PgrA protein indicated that it contained a collagen-like cell surface anchor motif. These results suggest that the pgr gene may be a useful molecular marker for epidemiological studies

    Structure and thermal history of the Wełnowiec dump, Poland : a municipal dump rehabilitated with coal waste

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    The Wełnowiec municipal dump, Katowice, Poland, rehabilitated with coal waste, is self-heating and igniting. This paper presents a novel application of the use of electrical- and resistivity geophysical methods in the investigation of burning coal waste to help explain why the heating occurred. Geoelectrical methods allowed the internal structure of the dump to be revealed, and the municipal wastes and their rehabilitation cover containing coal waste to be differentiated. Instead of a planned 2.2-m-thick multi-barrier system, the cover consists of irregularly distributed material of varying thickness ( 5%). This caused the fire to arise 3–4 years after the coal waste deposition. In areas where the rehabilitation layer is<3m thick, a landslide enabled oxygen access, initiating self-heating. Changes in conductivity clearly identify sites of active burning where measured conductivity values are more than twice those for parts of the dump with no thermal activity. Field observations in particular, complemented to a degree by petrographic, mineralogical and geochemical data, enabled four types of heating zones to be distinguished, namely, (1) initial zones of fire overtaking new volumes of coal waste, (2) active zones with temperatures < 400–500 °C in exhalation vents, (3) overburned zones characterized by long-lasting high temperatures (800-900 °C) and (4) short-lived zones, ephemeral (< 1–2 months) with temperatures between 70 and 100 °C. The geophysical methods applied could not distinguish between these zones. The combined results strongly suggest that the use of coal waste as a remediation layer covering waste dumps should be prohibited. Coal waste which, by its nature, is too prone to unpredictable self-heating and self-ignition with the potential environmental consequences that follow

    Editorial June 2020

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    HEPATITIS C VIRUS GENOTYPING IN CHRONIC HEPATITIS C PATIENTS

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    Chronic hepatitis C virus infection is a massive worldwide healthcare burden with estimated costs in the USA alone of over $5 billon per annum. The virus has a 9.5kb positive sense single-stranded RNA genome with striking heterogeneity between isolates, which has led to it being divided into 6 genotypes and more than 50 subtypes and many quasispecies that has been arisen due to the infidelity of the viral polymerase, which lacks of a proofreading function. The virus exists as a range of related but not identical species at the quasispecies. In each infected individual, HCV circulates as a quasispecies in which the population consists of a number of closely related but distinct genetic species. The distribution of the genotype might be influenced by the mode of transmission and racial group. The only current effective treatment is combination therapy with pegylated interferon plus ribavirin (peg-IFNα + RBV) for 24–48 weeks based for genotypes 1 and 4 is 48 weeks, whereas the treatment for genotypes 2 and 3 is completed in 24 weeks. It has proved effective in up to 50% of those infected with HCV genotype 1 and 4 and it varies with other genotypes. HCV genotype is consider to be a clinically important parameter for determining both; the potential response and the duration of treatment.

    Bargaining with Optimism

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    Excessive optimism is a prominent explanation for bargaining delays. Recent results demonstrate that optimism plays a subtle role in bargaining, and its careful analysis may shed valuable insights into negotiation behavior. This article reviews some of these results, focusing on the following findings. First, when there is a nearby deadline, optimistic players delay the agreement to the last period before the deadline, replicating a broad empirical regularity known as the deadline effect. Second, there cannot be a substantial delay under persistent optimism; i.e., excessive optimism alone cannot explain delays. Third, when optimistic players are expected to learn during the negotiation, they delay the agreement in order to persuade their opponents. The delays in these results can be quite costly, Pareto inefficient, and common knowledge at the beginning of the game

    Isolation of the Bacteriophage DinoHI from Dichelobacter nodosus and its Interactions with other Integrated Genetic Elements

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    The Gram-negative anaerobic pathogen Dichelobacter nodosus carries several genetic elements that integrate into the chromosome. These include the intA, intB, intC and intD elements, which integrate adjacent to csrA and pnpA, two putative global regulators of virulence and the virulence-related locus, vrl, which integrates into ssrA. Treatment of D. nodosus strains with ultraviolet light resulted in the isolation of DinoHI, a member of the Siphoviridae and the first bacteriophage to be identified in D. nodosus. Part of the DinoHI genome containing the packaging site is found in all D. nodosus strains tested and is located at the end of the vrl, suggesting a role for DinoHI in the transfer of the vrl by transduction. Like the intB element, the DinoHI genome contains a copy of regA which has similarity to the repressors of lambdoid bacteriophages, suggesting that the maintenance of DinoHI and the intB element may be co-ordinately controlled

    Multiple locus VNTR analysis highlights that geographical clustering and distribution of Dichelobacter nodosus, the causal agent of footrot in sheep, correlates with inter-country movements

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    Dichelobacter nodosus is a Gram-negative, anaerobic bacterium and the causal agent of footrot in sheep. Multiple locus variable number tandem repeat (VNTR) analysis (MLVA) is a portable technique that involves the identification and enumeration of polymorphic tandem repeats across the genome. The aims of this study were to develop an MLVA scheme for D. nodosus suitable for use as a molecular typing tool, and to apply it to a global collection of isolates. Seventy-seven isolates selected from regions with a long history of footrot (GB, Australia) and regions where footrot has recently been reported (India, Scandinavia), were characterised. From an initial 61 potential VNTR regions, four loci were identified as usable and in combination had the attributes required of a typing method for use in bacterial epidemiology: high discriminatory power (D > 0.95), typeability and reproducibility. Results from the analysis indicate that D. nodosus appears to have evolved via recombinational exchanges and clonal diversification. This has resulted in some clonal complexes that contain isolates from multiple countries and continents; and others that contain isolates from a single geographic location (country or region). The distribution of alleles between countries matches historical accounts of sheep movements, suggesting that the MLVA technique is sufficiently specific and sensitive for an epidemiological investigation of the global distribution of D. nodosus

    Young carers in England: findings from the 2018 BBC survey on the prevalence and nature of caring among young people

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    Background Many young people are involved in caring for parents, siblings, or other relatives who have an illness or disability. The aim of this study was to estimate the prevalence of caring by young people in England. Method A national survey of 925 English young people was conducted using the 18‐item survey version of the Multidimensional Assessment of Caring Activities Checklist for Young Carers. Results Around 7% of young people were identified as doing at least a high amount of caring activity and 3% a very high amount. Most frequently, caring by a young person is for a mother or a sibling, with a physical disability. Caring activity consisted mostly of domestic activities, household management, and emotional care. Conclusion This study provides the most up to date and methodologically sophisticated survey data on the prevalence of young caring in England, with implications for policy and practice

    A Galactic Bar to Beyond the Solar Circle and its Relevance for Microlensing

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    The Galactic kinematics of Mira variables have been studied using infrared photometry, radial velocities, and Hipparcos parallaxes and proper motions. For Miras in the period range 145 to 200 days (probably corresponding to [Fe/H] in the range -0.8 to -1.3) the major axes of the stellar orbits are concentrated in the first quadrant of Galactic longitude. This is interpreted as a continuation of the bar-like structure of the Galactic Bulge out to the solar circle and beyond.Comment: 6 pages, 2 figures. To be published in: Microlensing 2000. ASP Conference Series, Eds. J W Menzies, P Sacket
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