Application of poly(ethylene glycol)-based aqueous biphasic systems as reaction and reactive extraction media

Poly(ethylene glycol)-based aqueous biphasic systems (PEG-ABSs) have been investigated as tunable reaction media, in the example presented here, to control the oxidation of cyclohexene to adipic acid with hydrogen peroxide. The production of adipic acid was found to increase from the monophasic to the biphasic regimes, was greatest at short tie-line lengths (close to the system's critical point), and demonstrates how control of the ABS media, through changes in system composition, PEG, salt, and tie-line length, can be used to readily tune and control reactivity and product isolation in these aqueous biphasic reactive extraction systems. Challenges in using this system, including possible oxidation reactions of the PEG-OH end groups, are also discussed.

The diverse geographies of rural gentrification in Scotland

Gentrification has for too long been investigated as an urban phenomenon. Only relatively recently has it been viewed as an avenue for fruitful rural research. This paper focuses on the repopulation of rural Scotland. Using survey and interview data it examines evidence of gentrification among in-migration flows and seeks to explore both the social transformation of rural areas and the social displacement of rural residents.

The findings point towards important geographical variations. Not all in-migration represents gentrification, and where it does gives rise to very differing impacts. Clear spatial divisions in the local housing market are identified, and evidence is obtained to support a number of differing theoretical debates. Issues of social displacement and population replacement are explored, with the paper tentatively suggesting an important link between urban and rural gentrification processes. Finally, temporal and geographical phases of gentrification are identified. Collectively these findings have direct relevance to how we define gentrification.

Media coverage of sustainable development issues – attention cycles or punctuated equilibrium?

Over the last two decades there has been a marked change in the way that the public perceives environmental issues and the concepts associated with sustainable development. Few would argue that this has moved into the mainstream of public consciousness. Coverage of sustainability related concepts within the media, as illustrated by a sample of 112 worldwide newspapers, shows a clear upward trajectory. Taking the example of climate change and sustainable development this paper explores this increasing coverage, and arguably awareness of, sustainability concepts and considers parallels with the concepts of punctuated equilibrium and issue-attention cycles.

Development of selective media for the isolation of yeasts and filamentous fungi from the sputum of adult patients with cystic fibrosis (CF)

Yeasts and filamentous fungi are beginning to emerge as significant microbial pathogens in patients with cystic fibrosis (CF), particularly in relation to allergic-type responses, as seen in patients with allergic bronchopulmonary aspergillosis (ABPA), Aspergillus bronchitis and in invasive fungal disease in lung transplant patients. Four fungal media were compared in this study, including Sabouraud Dextrose Agar (SDA) and Medium B, with and without the addition of selective antibiotics, where antibiotic-supplemented media were designated with (+). These media were compared for their ability to suppress contaminating, mainly Gram-ve pathogens, in CF sputa (Pseudomonas aeruginosa, Burkholderia cepacia complex [BCC] organisms) and to enhance the growth of fungi present in CF sputum. Medium B consisted of glucose (16.7 g/l), agar (20 g/l), yeast extract (30 g/l) and peptone (6.8 g/l) at pH 6.3 and both SDA(+) and Medium B+ were supplemented with cotrimethoxazole, 128 mg/l; chloramphenicol, 50 mg/l; ceftazidime, 32 mg/l; colistin, 24 mg/l). Employment of SDA(+) or Medium B+ allowed an increase in specificity in the detection of yeasts and moulds, by 42.8% and 39.3%, respectively, over SDA when used solely. SDA(+) had a greater ability than Medium B+ to suppress bacterial growth from predominantly Gram-ve co-colonisers. This is a significant benefit when attempting to detect and isolate fungi from the sputum of CF patients, as it largely suppressed any bacterial growth, with the exception of the BCC organisms, thus allowing for an increased opportunity to detect target fungal organisms in sputum and represented a significant improvement over the commercial medium (SDA), which is currently used. Overall, both novel selective media were superior in their ability to suppress bacteria in comparison with the commercially available SDA medium, which is routinely employed in most clinical microbiology diagnostic laboratories presently. Alternatively, Medium B+ had a great ability to grow fungi than SDA(+) and when employed together, the specificity of combined use was 82%, with a sensitivity for yeasts, filamentous fungi, and combined overall fungi of 96.0%, 92.3% and 96.0%, respectively. Overall, when employing one fungal selective medium for the routine detection of yeasts and filamentous fungi in the sputum of CF patients, we would recommend employment of Medium B+. However, we would recommend the combined employment of SDA(+) and Medium B+, in order to synergistically isolate and detect the greatest number of fungi present in CF sputa. (C) 2008 European Cystic Fibrosis Society. Published by Elsevier B.V All rights reserved.

Monitoring microbial sulfate reduction in porous media using multi-purpose electrodes

There is growing interest in the application of electrode-based measurements for monitoring microbial processes in the Earth using biogeophysical methods. In this study, reactive electrode measurements were combined to electrical geophysical measurements during microbial sulfate reduction occurring in a column of silica beads saturated with natural river water. Electrodic potential (EP), self potential (SP) and complex conductivity signals were recorded using a dual electrode design (Ag/AgCl metal as sensing/EP electrode, Ag/AgCl metal in KCl gel as reference/SP electrode). Open-circuit potentials, representing the tendency for electrochemical reactions to occur on the electrode surfaces, were recorded between sensing/EP electrode and reference/SP electrode and showed significant spatiotemporal variability associated with microbial activity. The dual electrode design isolates the microbial driven sulfide reactions to the sensing electrode and permits removal of any SP signal from the EP measurement. Based on the known sensitivity of a Ag electrode to dissolved sulfide, we interpret EP signals exceeding 550 mV recorded in this experiment in terms of bisulfide (HS-) concentration near multiple sensing electrodes. Complex conductivity measurements capture an imaginary conductivity (s?) signal interpreted as the response of microbial growth and biomass formation in the column. Our results suggest that the implementation of multipurpose electrodes, combining reactive measurements with electrical geophysical measurements, could improve efforts to monitor microbial processes in the Earth using electrodes.

Becoming private property: custom, law, and the geographies of ‘ownership’ in 18th- and 19th-century England

The making private of hitherto public goods is a central tenet of neoliberalism. From land in Africa, Asia, and South America to the assertion of property rights over genes and cells by corporations, the process(es) of making private property matters more than ever. And yet, despite this importance, we know remarkably little about the spatial plays through which things become private property. In this paper I seek to address this imbalance by focusing upon the formative context of 18th- and early-19th-century England. The specific lens is wood, that most critical of all ‘natural’ things other than land in the transition to market-driven economies. It is shown that the interplay between custom, law, and local practices rendered stable and aspatial definitions of property impossible. Whilst law was the key technology through which property was mediated, the cadence of particular places gave these mediations distinctive forms. I conclude that not only must we take property seriously, but we must also take the conditions and contexts of its making seriously too.