During the fifteen years prior to the first publication of this book in 2003, existing models of linguistic politeness generated a huge amount of empirical research. Using a wide range of data from ...real-life speech situations, this introduction to politeness breaks away from the limitations of those models and argues that the proper object of study in politeness theory must be commonsense notions of what politeness and impoliteness are. From this, Watts argues, a more appropriate model, one based on Bourdieu's concept of social practice, is developed. The book aims to show that the terms 'polite' and 'impolite' can only be properly examined as they are contested discursively. In doing so, 'polite' and 'impolite' utterances inevitably involve their users in a struggle for power. A radically new account of linguistic politeness, the book will appeal to students and researchers in a wide range of disciplines, in linguistics and the social sciences.
The activation of persulfate by phenols was investigated to further the understanding of persulfate chemistry for in situ chemical oxidation (ISCO). Phenol (pK a = 10.0) activated persulfate at pH 12 ...but not at pH 8, suggesting activation occurred only via the phenoxide form. Evaluation of the phenoxide activation mechanism was complicated by the concurrent activation of persulfate by hydroperoxide anion, which is generated by the base catalyzed hydrolysis of persulfate. Therefore, phenoxide activation was investigated using pentachlorophenoxide at pH 8.3, midway between the pK a of pentachlorophenol (pK a = 4.8) and that of hydrogen peroxide (pK a = 11.8). Of the two possible mechanisms for phenoxide activation of persulfate (reduction or nucleophilic attack) the results were consistent with reduction of persulfate by phenoxide with oxidation of the phenoxide. The concentration of phenoxide required for maximum persulfate activation was low (1 mM). The results of this research document that phenoxides activate persulfate via reduction; phenolic moieties ubiquitous to soil organic matter in the subsurface may have a significant role in the activation of persulfate during its injection into the subsurface for ISCO. Furthermore, the results provide the foundation for activation of persulfate by other organic anions without the toxicity of phenols, such as keto acids.
Catalyzed H2O2 propagations (CHP) is characterized by the most robust reactivity of any of the in situ chemical oxidation (ISCO) technologies because it generates the strong oxidant hydroxyl radical ...along with nucleophiles + reductants, such as superoxide radical. The most common groundwater contaminants, trichloroethylene (TCE) and perchloroethylene (PCE), were used as model contaminants in evaluating the effect of hydrogen peroxide (H2O2) dosage on contaminant destruction kinetics. Both TCE and PCE degradation rates increased with H2O2 dosages up to 0.1 M, and then decreased with higher H2O2 dosages. Parallel reactions conducted with the addition of the hydroxyl radical scavenger 2-propanol and the hydroxyl radical-specific probe nitrobenzene confirmed that hydroxyl radical is primarily responsible for TCE and PCE degradation; however, 5–20% of their degradation was attributed to a non-hydroxyl radical mechanism. Reactions conducted with the superoxide probe tetranitromethane showed that superoxide generation rates increased with increasing H2O2 doses. These results were confirmed by electron spin resonance spectroscopy. Therefore, the non-hydroxyl radical pathway for TCE and PCE degradation at H2O2 ≥0.5 M was likely via nucleophilic attack by superoxide. The results of this research demonstrate that contaminants present in the aqueous phase that are reactive with hydroxyl radical require only low doses of H2O2 (≤0.1 M), but subsurface systems contaminated with species not reactive with hydroxyl radical (e.g., carbon tetrachloride) require H2O2 concentrations ≥0.5 M.
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•Catalyzed H2O2 Propagations is a robust in situ chemical oxidation technology.•TCE and PCE degradation was studied using a range of H2O2 dosages.•Hydroxyl radical was the predominant transforming species.•Superoxide was an additional transforming species at H2O2 dosages ≥0.5 M.•High doses of H2O2 are necessary only when superoxide driven treatment is needed.
Classification of the vasculitides has been traditionally based on vessel size. The American College of Rheumatology (ACR) criteria were developed in the 1980s and published in 1990 before the ...development of ANCA testing and modern imaging techniques such as MRI and PET scanning, and therefore, these criteria are not fit for use in 2010s. The Chapel Hill Consensus Conference provided a framework for defining various types of vasculitis. In the next two years, new classification criteria will be published from the DCVAS study, which will provide a modern system for the classification of vasculitis for clinical studies.
The epidemiology of vasculitides is increasingly well studied; however, there remain gaps in our knowledge of the occurrence of vasculitis in many populations, especially from the third world or those with health care systems that do not permit ready collection of accurate epidemiological data. Giant cell arteritis presents in the elderly and those of Northern European ancestry; ANCA-associated vasculitis appears to have a consistent overall occurrence, but there are differences in the occurrence of MPO and PR3 vasculitis between populations. Kawasaki disease occurs most commonly in Asian populations, especially Japanese, and in those aged less than 5 years. It is currently the most common cause of acquired cardiac disease in those populations.
Global epidemiology of vasculitis Watts, Richard A; Hatemi, Gulen; Burns, Jane C ...
Nature reviews. Rheumatology,
01/2022, Letnik:
18, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The many forms of vasculitis are characterized by inflammation of blood vessels, leading to potentially long-term sequelae including vision loss, aneurysm formation and kidney failure. Accurate ...estimation of the incidence and prevalence has been hampered by the absence of reliable diagnostic criteria and the rarity of these conditions; however, much progress has been made over the past two decades, although data are still lacking from many parts of the world including the Indian subcontinent, China, Africa and South America. Giant cell arteritis occurs in those aged 50 years and over and seems to mainly affect persons of northern European ancestry, whereas Takayasu arteritis occurs mainly in those aged under 40 years. By contrast, Kawasaki disease mainly occurs in children aged under 5 years and is most common in children of Asian ancestry, and IgA vasculitis occurs in children and adolescents. Although much less common than giant cell arteritis, the different forms of antineutrophil cytoplasmic antibody-associated vasculitis are being increasingly recognized in most populations and occur more frequently with increasing age. Behçet syndrome occurs most commonly along the ancient silk road between Europe and China. Much work needs to be done to better understand the influence of ethnicity, geographical location, environment and social factors on the development of vasculitis.
Mechanism of Base Activation of Persulfate Furman, Olha S; Teel, Amy L; Watts, Richard J
Environmental science & technology,
08/2010, Letnik:
44, Številka:
16
Journal Article
Recenzirano
Base is the most commonly used activator of persulfate for the treatment of contaminated groundwater by in situ chemical oxidation (ISCO). A mechanism for the base activation of persulfate is ...proposed involving the base-catalyzed hydrolysis of persulfate to hydroperoxide anion and sulfate followed by the reduction of another persulfate molecule by hydroperoxide. Reduction by hydroperoxide decomposes persulfate into sulfate radical and sulfate anion, and hydroperoxide is oxidized to superoxide. The base-catalyzed hydrolysis of persulfate was supported by kinetic analyses of persulfate decomposition at various base:persulfate molar ratios and an increased rate of persulfate decomposition in D2O vs H2O. Stoichiometric analyses confirmed that hydroperoxide reacts with persulfate in a 1:1 molar ratio. Addition of hydroperoxide to basic persulfate systems resulted in rapid decomposition of the hydroperoxide and persulfate and decomposition of the superoxide probe hexachloroethane. The presence of superoxide was confirmed with scavenging by Cu(II). Electron spin resonance spectroscopy confirmed the generation of sulfate radical, hydroxyl radical, and superoxide. The results of this research are consistent with the widespread reactivity reported for base-activated persulfate when it is used for ISCO.
The relationship between language and music has much in common - rhythm, structure, sound, metaphor. Exploring the phenomena of song and performance, this book presents a sociolinguistic model for ...analysing them. Based on ethnomusicologist John Blacking's contention that any song performed communally is a 'folk song' regardless of its generic origins, it argues that folk song to a far greater extent than other song genres displays 'communal' or 'inclusive' types of performance. The defining feature of folk song as a multi-modal instantiation of music and language is its participatory nature, making it ideal for sociolinguistic analysis. In this sense, a folk song is the product of specific types of developing social interaction whose major purpose is the construction of a temporally and locally based community. Through repeated instantiations, this can lead to disparate communities of practice, which, over time, develop sociocultural registers and a communal stance towards aspects of meaningful events in everyday lives that become typical of a discourse community.
Classification and epidemiology of vasculitis: Emerging concepts Ecclestone, Tegwen; Watts, Richard A.
Baillière's best practice and research in clinical rheumatology/Baillière's best practice & research. Clinical rheumatology,
03/2023, Letnik:
37, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The recent publication of the American College of Rheumatology (ACR)-European Alliance of Associations for Rheumatology (EULAR) classification criteria for large vessel vasculitis and anti-neutrophil ...cytoplasmic antibody (ANCA)-associated vasculitides (AAVs) has provided modern criteria for the classification of these conditions, which incorporate contemporary methods of investigation and diagnosis. Further validation is required in independent cohorts, especially from populations that were not well represented in the development cohort.
Studies of the occurrence of large vessel vasculitis report that Takayasu arteritis is a rare disease in most populations, and giant cell arteritis is the most common vasculitis in older populations. The incidence of AAV appears to have plateaued, but the prevalence is increasing as a result of lower mortality.
The new classification criteria may affect the reported incidence and prevalence, and studies will be needed to confirm this. The impact of COVID-19 on the occurrence of the vasculitides is not completely known, but there is evidence of reduced occurrence of Kawasaki disease and IgA-associated vasculitis following lockdowns with reduced transmission of possible trigger infectious agents.
•The antibiotic effect on biogas production during anaerobic digestion was studied.•⩽280mg/L sulfamethazine and ⩽91mg/L tylosin did not inhibit biogas production.•⩽350mg/L ampicillin and ⩽6.4mg/L ...florfenicol did not inhibit biogas production.•Ampicillin, florfenicol, and tylosin were rapidly degraded within 5d of digestion.•Sulfamethazine and degradation products from florfenicol and tylosin were persistent.
The impacts of four common animal husbandry antibiotics (ampicillin, florfenicol, sulfamethazine, and tylosin) on anaerobic digestion (AD) treatment efficiency and the potential for antibiotic degradation during digestion were evaluated. Sulfamethazine and ampicillin exhibited no impact on total biogas production up to 280 and 350mg/L, respectively, although ampicillin inhibited biogas production rates during early stages of AD. Tylosin reduced biogas production by 10–38% between 130 and 913mg/L. Florfenicol reduced biogas by ∼5%, 40% and 75% at 6.4, 36 and 210mg/L, respectively. These antibiotic concentrations are higher than commonly seen for mixed feedlot manure, so impacts on full scale AD should be minimal. Antibiotic degradation products were found, confirming AD effectively degraded ampicillin, florfenicol, and tylosin, although some products were persistent throughout the process. Contamination of AD solid and liquid effluents with sulfamethazine and antibiotic transformation products from florfenicol and tylosin could present an environmental concern.
•Four antibiotics were studied: chloramphenicol, florfenicol, spiramycin, and tylosin.•Antibiotic hydrolysis was examined under different pH and temperature regimes.•Antibiotics persisted and ...exhibited no observable hydrolysis under ambient conditions.•Acid- and base-catalyzed hydrolysis occurred at elevated temperatures (50–60°C).•Degradation products may remain bioactive, but less than parent compound.
Antibiotics that enter the environment can present human and ecological health risks. An understanding of antibiotic hydrolysis rates is important for predicting their environmental persistence as biologically active contaminants. In this study, hydrolysis rates and Arrhenius constants were determined as a function of pH and temperature for two amphenicol (chloramphenicol and florfenicol) and two macrolide (spiramycin and tylosin) antibiotics. Antibiotic hydrolysis rates in pH 4–9 buffer solutions at 25°C, 50°C, and 60°C were quantified, and degradation products were characterized. All of the antibiotics tested remained stable and exhibited no observable hydrolysis under ambient conditions typical of aquatic ecosystems. Acid- and base-catalyzed hydrolysis occurred at elevated temperatures (50–60°C), and hydrolysis rates increased considerably below pH 5 and above pH 8. Hydrolysis rates also increased approximately 1.5- to 2.9-fold for each 10°C increase in temperature. Based on the degradation product masses found, the functional groups that underwent hydrolysis were alkyl fluoride, amide, and cyclic ester (lactone) moieties; some of the resultant degradation products may remain bioactive, but to a lesser extent than the parent compounds. The results of this research demonstrate that amphenicol and macrolide antibiotics persist in aquatic systems under ambient temperature and pH conditions typical of natural waters. Thus, these antibiotics may present a risk in aquatic ecosystems depending on the concentration present.
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