From existing in situ, high-resolution measurement technologies to lab-on-a-chip – the future of water quality monitoring?

Abstract. This paper introduces new insights into the hydrochemical functioning of lowland river-systems using field-based spectrophotometric and electrode technologies. The streamwater concentrations of nitrogen species and phosphorus fractions were measured at hourly intervals on a continuous basis at two contrasting sites on tributaries of the River Thames, one draining a rural catchment, the River Enborne, and one draining a more urban system, The Cut. The measurements complement those from an existing network of multi-parameter water quality sondes maintained across the Thames catchment and weekly monitoring based on grab samples. The results of the sub-daily monitoring show that streamwater phosphorus concentrations display highly complex, seemingly chaotic, dynamics under storm conditions dependent on the antecedent catchment wetness, and that diurnal phosphorus and nitrogen cycles occur under low flow conditions. The diurnal patterns highlight the dominance of sewage inputs in controlling the streamwater phosphorus and nitrogen concentrations at low flows, even at a distance of 7 km from the nearest sewage works in the rural, River Enborne, and that the time of sample collection is important when judging water quality against ecological thresholds or standards. An exhaustion of the supply of phosphorus from diffuse and septic tank sources during storm events was evident and load estimation was not improved by sub-daily monitoring beyond that achieved by daily sampling because of the eventual reduction in the phosphorus mass entering the stream during events. The dominance of respiration over photosynthesis in The Cut indicated a prevalence of heterotrophic algae, and the seasonal patterns in respiration and photosynthesis corresponded with those of temperature and light in this nutrient over-enriched stream. These results highlight the utility of sub-daily water quality measurements but the deployment of modified wet-chemistry technologies into the field was limited by mains electricity availability. A new approach is therefore needed to allow measurement of a wide range of analytes at a broader range of locations for the development of water quality web-sensor networks. The development and field deployment of a miniaturised "lab-on-a-chip" ion chromatograph is proposed and justified. </jats:p

Agent-Based Simulation as an Implementation of Methodological Individualism

This paper investigates the relationship between methodological individualism (MI) and Agent-Based Simulation (ABS). We discuss and analyze a thesis defended by philosophers Caterina Marchionni and Petri Ylikoski (2013). The thesis maintains that, since MI is often considered to be a reductionist approach, it is confusing and meaningless to assume that ABS, which is a non-reductionist and emergentist explanatory model, is committed to MI. We reject this thesis arguing that, from a philosophical standpoint, addressing the problem of the consistency between MI and ABS from a strictly utilitarian perspective is unsatisfactory. We analyze this problem in more substantial terms, i.e. focusing on its more theoretical and conceptual aspects. Moreover, we maintain that ABS explanations must be regarded as individualist explanations and provide a set of logical and historical arguments against the widespread interpretation of MI in terms of reductionism

The Sage Handbook of The Philosophy of Social Sciences

xvii, 749 p.; ill.; 25 cm

An assessment of the fate, behaviour and environmental risk associated with sunscreen TiO2 nanoparticles in UK field scenarios

The fate of Ti was examined in an activated sludge plant serving over 200,000 people. These studies revealed a decrease of 30 to 3.2 µg/L of Ti<0.45 µm from influent to effluent and a calculated Ti presence of 305 mg/kg DW in wasted sludge. Thus, using sludge as a fertiliser would result in a predicted deposition of up to 250 mg/m2 of Ti to soil surfaces using a recommended maximal agricultural application rate. Given the major use of TiO2 in many industrial and domestic applications where loss to the sewer is possible, this measured Ti was presumed to have been largely TiO2, a proportion of which will be nanoparticle sized. To assess the behaviour of engineered nanoparticle (ENP) TiO2 in sewage and toxicology studies, Optisol (Oxonica Materials Ltd) and P25 (Evonik Industries AG), which are representative of forms used in sunscreen and cosmetic products, were used. These revealed a close association of TiO2 ENPs with activated sludge. Using commercial information on consumption, and removal rates for sewage treatment, predictions were made for river water concentrations for sunscreen TiO2 ENPs for the Anglian and Thames regions in Southern England. The highest predicted value from these exercises was 8.8 µg/L for the Thames region in which it was assumed one in four people used the recommended application of sunscreen during a low flow (Q95) period. Ecotoxicological studies using potentially vulnerable species indicated that 1,000 µg/L TiO2 ENP did not affect the viability of a mixed community of river bacteria in the presence of UV light. Direct exposure to TiO2 ENPs did not impair the immuno-effectiveness of earthworm coelomocyte cells at concentrations greatly above those predicted for sewage sludge

"Our Granada": The Granada Theatre, Wellington Street, Sherbrooke, Quebec, Canada, America, the World and Me

Built at the height of the atmospheric theatre fad in early 1929, the Granada Theatre of Sherbrooke, Quebec has been many things to many people over the years. Starting as a double-bill house of United Amusements of Quebec (owned by Famous Players of Toronto,in turn owned by Paramount of New York), the Granada eventually became the premier performance space in Sherbrooke in the 1940s and 1950s. It was eventually replaced in this function in the late 1960s by cultural centres at the two local universities. While it was sold off by Famous Players in the early 1970s it still survives relatively intact, at the end of this century a curious architectural reminder of how things once were and perhaps still are. The theatre's past, present and future provide the author with an opportunity to reflect upon his own place in late 20th century Quebec. Le Théâtre Granada, un cinéma atmospherique de l'année 1929 qui existe encore à la rue Wellington de Sherbrooke, Québec, offre pour l'auteur d'opportunité de faire des réflexions politiques, culturels et personnels. La nature de cet éspace comme un produit simultané local, provincial, fédéral, continental et mondial sugget pour l'auteur que ses éspaces comme le Granada peut donner aux chercheurs un terrain ou sujet fertile pour l'analyse des cultures québécoises