169 research outputs found

    Extra-intestinal pathogenic Escherichia coli in the UK. The importance in bacteraemia versus urinary tract infection, colonisation of widespread clones and specific virulence factors

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    PhDExtra-intestinal pathogenic Escherichia coli (ExPEC) are a significant cause of urinary tract infections and bacteraemia in the UK and around the world. These E. coli primarily belong to phylogenetic groups B2 and D, with the clones ST131, ST127, ST95, ST73 and ST69 responsible for the majority of these infections. In the UK, studies of ExPEC have focused on isolates from the North of England, ST131 strains and ExPEC that possess extended-spectrum beta-lactamase (ESBL) enzymes. Therefore, very little is understood about the UK ExPEC population as a whole, the breadth of virulence factors contributing to these infections and the differences between urinary and bloodstream-derived ExPEC. In this study ST131 was more frequently detected in bloodstream isolates and ST95 was most prevalent in urinary isolates. Comparative virulence of the major clones in the Galleria mellonella infection model revealed ST131 isolates to effect the highest mortality, although serogroup O6, which is linked with ST73, was also associated with high mortality, potentially explaining the success of ST73-O6 in bacteraemia. Analysis of virulence factors identified pap, afa/dra and kpsMTII as important determinants in isolates causing urosepsis and those of ST131, while fyuA and fimH were distinctly lacking, demonstrating their role as colonisation factors rather than virulence factors. Although these findings are important, with appropriate treatment of urinary tract infections they can become redundant, as ExPEC would be eradicated before causing a severe infection such as bacteraemia or urosepsis. In urinary isolates, resistance to trimethoprim approached 50% and ampicillin resistance was >70%, while ST131 isolates as a whole demonstrated ciprofloxacin and trimethoprim resistance >50%. Together these indicate that empirical UTI guidelines need to be revisited, to prevent recurrence of infection and ascension to the kidneys and bloodstream. In addition, data from this study can be used to develop a point-of-care test to detect ST131, to guide appropriate treatment, without the delay associated with referring a urine specimen for microbiological investigation.Public Health Englan

    Geochemistry and electron spin resonance of hydrothermal dickite (Nowa Ruda, Lower Silesia, Poland) : Vanadium and chromium

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    Geochemical analyses for trace V and Cr have been done on a representative sample of a typical hydrothermal dickite/kaolinite filling vein at Nowa Ruda. The mineralogy of the sample is comparatively simple, dickite being the principal component (ca. 91 % of the total sample). Geochemical fractionation and inductively coupled plasma-optical emission spectrometry (ICP-OES) indicate that most ( > 90 % of total metal) of the V and Cr reside in the dickite. Electron Spin Resonance (ESR) shows that most ( > 70 %) of the V in the dickite structure is in the form of vanadyl (VO2+) ions. A high concentration of Cr3+ is also detected in this structure by ESR. The combination of geochemical and spectroscopic tools applied to VO2+ and Cr3+ allow one to specify the Eh ( > 0.4 V, highly oxidizing) and pH ( 4.0, highly acidic) of the solution during the formation of dickite from the Nowa Ruda Basin. Substantial proportions of the V and Cr (as well as VO2+ and Cr3+) in the dickite structure were probably contained in an original hydrothermal acid water. We suggest that hot hydrothermal waters leached the surrounding varieties of gabbroids enriched in V and Cr for the dickite-forming solution. The results of this work have shown V and Cr are potentially reliable indicators for geochemical characterization of the physicochemical conditions of their formation. The bulk-rock V/Cr ratio in hydrothermal dickites and kaolinites from Nowa Ruda, Sonoma (California, USA), Cigar Lake (Saskatchewan, Canada) and Teslić (Bosnia and Hercegovina) is also briefly explored here as a potential tracer of redox state during their formation

    Plant occurrence on burning coal waste - a case study from the Katowice-Wełnowiec dump, Poland

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    Coal-waste dumps superimposed on former rubbish dump frequently undergo selfheating and selfignition of organic matter dispersed in the waste. The special conditions for plant growth generated as a result have been investigated since 2008 on the municipal dump reclaimed with coal wastes in Katowice-Welnowiec, Poland. The plants observed most frequently where heating has occurred are Sisymbrium loeselii, Artemisia vulgaris, Sonchus arvensis, Chenopodium album, Achillea millefolium, Cirsium arvense, Amaranthus retrollexus, Atriplex niters and Solanum nigrum. Some new, rare species such as Portulaca oleracea, first noticed in 2011, may be added. Most of encroaching species are annual, alien archeophytes and neophytes. Native species are mainly perennials. The majority of these species show a tendency to form specimens of huge size (gigantism). The abundance of emitted CO2 and nitrogen compounds is the likely cause of this. Additionally, the plants growing there are not attacked by insects. The heating of the ground liquidates the natural seed bank. After cooling, these places are seeded by species providing seeds at that very moment (pioneer species). Heated places on the dumps allow plant growth even in the middle of winter. As the seasonal vegetation cycle is disturbed, plants may be found seeding, blooming and fruiting at the same time

    Self-heating coal waste fire monitoring and related environmental problems : case studies from Poland and Ukraine

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    The self-heating of coal waste dumps is considered as a serious environmental issue, wherever active or inactive coal mining has been present. This issue is introduced from two active coal mining regions from Poland (Upper Silesian Coal Basin) and Ukraine (Donetsk Coal Basin) based on mineralogy, organic petrography and geochemistry, and remote sensing techniques. Thermally affected coal wastes reveal changes recorded by organic and mineral matter. Irregular cracks and fissures appear within and at the edges of organic matter particles, which are oxidised, devolatilised and plasticised. Mineral phases underwent oxidation, dehydration, structure rebuilding and recrystallisation. Highest temperatures generated during the fire cause melting and paralava formation. During selfheating, some chalcophile elements like Hg (mostly present as HgS), Pb, Zn can be enriched and released, or different organic pollutants like phenols (originated from vitrinite particles), different PAHs with alkyl substitutes, chlorinated PAHs, or sulphur heterocycles are formed. The introduced remote sensing techniques helped to localise and monitor hot spots with different temperature ranges. Applying SWIR bands of Landsat hot spots from extremely burning dumps in Ukraine were successfully localised, however, only night-time scenes with SWIR can be used. The sun’s disturbing effects should be considered as an influential factor for both thermal imaging camera or satellite images. Thermal cameras can reveal the most detailed signs of low to high temperature anomalies with different cracks and line shapes

    The Behaviour of Siderite Rocks in an Experimental Imitation of Pyrometamorphic Processes in Coal-Waste Fires: Upper and Lower Silesian Case, Poland

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    Little is known of the influence of fluxes on the nature and the intensity of burning in coal-waste heaps. To gain some insight, two siderite samples, one each from coal-mining waste heaps in Upper- and Lower Silesian Coal Basins (Poland), were heated under identical conditions in a thermal chamber coupled to a powder X-ray di ractometer. Di erences in the behaviour of siderite phase and the products of its decomposition, mainly magnetite, wüstite, and olivine, are discussed. The waste heaps sampled underwent self-heating and self-ignition catalysed by fluxes. Though the samples are unlikely to be truly representative of the Silesian basins, the heterogeneous behaviour they displayed on heating merits description and explanation, as siderite is an important widely known flux in pyrometamorphic processes

    Lessons learned from a constitutional controversy on the Mexican water management

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    Between March and May 2020, fourteen municipalities in Chihuahua, Mexico, initiated a jurisdictional process called ‘constitutional controversy’ at Mexico's Supreme Court of Justice, against the Congress, the President, the Commander of the National Guard, and the National Water Commission. These municipalities sued for the unconstitutionality of the Federal Government's actions regarding the water extraction in the "La Boquilla" dam, in the light of water legislation unsuitable to foster public participation in water management. Moreover, the lack of public participation in the 'La Boquilla' dam water management have resulted in several clashes between water users and the National Guard. Amid the current drafting process of the General Water Law for Mexico, it is important to understand how the Mexican water legal framework has failed as an institutional tool to achieve sustainable water management. This report discusses the “La Boquilla” dam case to highlight the inability of the current Mexican water legal framework to address water-related problems. In doing so, some of the main problems in Mexican water laws’ structure are analysed to show why those laws are hardly complied with and weakly enforced, which has resulted in conflicts and water mismanagement. Finally, it discusses the potential of stakeholder engagement and local water policies for strengthening the rule of law with respect to water for the upcoming General Water Law for Mexico

    Crystal Chemistry of an Erythrite-Köttigite Solid Solution (Co3–xZnx) (AsO4)2·8H2O

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    A wide compositional range, covering about 90% of an expected erythrite-köttigite substitutional solid solution with extreme compositions of (Co2.84Mg0.14Zn0.02) (AsO4)2·8H2O and (Zn2.74Co0.27) (AsO4)2·8H2O, was revealed in a suite of samples from a polymetallic ore deposit in Miedzianka, SW Poland. Members of the solid solution series were examined by means of Electron Probe Microanalysis (EPMA), Scanning Electron Microscopy (SEM)/Energy-Dispersive Spectrometer (EDS), X-ray single-crystal and powder diffraction, and Raman spectroscopy. Metal cations were randomly distributed between two special octahedral sites in the erythrite–köttigite structure. In response to Co ↔ Zn substitutions, small but significant changes in bond distances (particularly in [AsO4] tetrahedra), rotation, and distortion of co-ordination polyhedra were observed. Two sub-series of dominant cationic substitutions (Co-Mg-Ni and Co-Fe-Zn) were noted within the arsenate series of vivianite-group minerals linked by erythrite. The paragenetic sequence erythrite → Zn-rich erythrite → Co-rich köttigite → köttigite reflects the evolution of the solution’s pH towards increased acidity and a relative increase in the concentration of Zn ions following precipitation of erythrite

    Public Participation and the Escazú Agreement: Implementation Challenges for Vulnerable Groups Amid a Global Pandemic

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    While the adoption of the Escazú Agreement is of importance, there are many obstacles in the Latin America and the Caribbean to the implementation of this treaty, especially in terms of public participation. Those obstacles are social and institutional challenges, such as culture of privilege, killing of environmental activists, and COVID-19. This article discusses to what extent the Escazú Agreement can potentially overcome the existing challenges and ensuring public participation for persons or groups in vulnerable situations

    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

    Self-Heating Coal Waste Fire Monitoring and Related Environmental Problems: Case Studies from Poland and Ukraine

    Get PDF
    The self-heating of coal waste dumps is considered as a serious environmental issue, wherever active or inactive coal mining has been present. This issue is introduced from two active coal mining regions from Poland (Upper Silesian Coal Basin) and Ukraine (Donetsk Coal Basin) based on mineralogy, organic petrography and geochemistry, and remote sensing techniques. Thermally affected coal wastes reveal changes recorded by organic and mineral matter. Irregular cracks and fissures appear within and at the edges of organic matter particles, which are oxidised, devolatilised and plasticised. Mineral phases underwent oxidation, dehydration, structure rebuilding and recrystallisation. Highest temperatures generated during the fire cause melting and paralava formation. During self-heating, some chalcophile elements like Hg (mostly present as HgS), Pb, Zn can be enriched and released, or different organic pollutants like phenols (originated from vitrinite particles), different PAHs with alkyl substitutes, chlorinated PAHs, or sulphur heterocycles are formed. The introduced remote sensing techniques helped to localise and monitor hot spots with different temperature ranges. Applying SWIR bands of Landsat hot spots from extremely burning dumps in Ukraine were successfully localised, however, only night-time scenes with SWIR can be used. The sun’s disturbing effects should be considered as an influential factor for both thermal imaging camera or satellite images. Thermal cameras can reveal the most detailed signs of low to high temperature anomalies with different cracks and line shapes
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