XXXVI. On Graptolites

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A ‘Post-Work’ World:Geographical Engagements with the Future of Work

This article reviews geographical research on labour market changes that pose a challenge to ‘work’ as a compelling category of analysis. Drawing inspiration from feminist scholarship that has sought to develop a frame for thinking about the concept of work so that other activities outside employment are recognised, it considers what everyday practices of work, including domestic and reproductive labour, can teach us about the realities and futures of contemporary capitalism. While ‘work’ has long served as a presumed norm or telos of ‘development’, this article considers the prospect of the ‘end of work’ and of a specific type of accompanying capitalist society. It outlines the challenges for policy making in bringing forth a ‘post-work’ world without cementing social and economic inequality

Theorizing Bioart Encounters after Gilbert Simondon

In recent years ‘bioart’ has been lauded in the social sciences for its creative engagements with the ontological stakes of new forms of biotechnical life in-the-making. In this paper I push further to explore the ontogenetic potentials of bioart-encounters to generate new capacities for thinking and perceiving the nonhuman agencies imbricated in the becoming of subjects. To explore this potential I stage an encounter with Gilbert Simondon’s philosophy of individuation, highlighting three implications for theorizations of the constitution and transformation of subjects. First, Simondon forces us to rethink the subject in terms of its transductive emergence from pre-individual processes, and its metastable susceptibility to ongoing transformations. Second, he substitutes voluntarist conceptions of thought with an involuntarist primacy of material encounters as the conditions for novel individuations. Finally, I argue that Simondon enables a thinking of the politics of the (bio)art-encounter in terms of its ontogenetic capacity to materially produce, rather than merely represent, new subjects and worlds.</jats:p

Threats to groundwater supplies from contamination in Sierra Leone, with special reference to Ebola care facilities

The outbreak of Ebola virus disease in West Africa in 2014 is the worst single outbreak recorded, and has resulted in more fatalities than all previous outbreaks combined. This outbreak has resulted in a large humanitarian effort to build new health care facilities, with associated water supplies. Although Ebola is not a water-borne disease, care facilities for Ebola patients may become sources of outbreaks of other, water-borne, diseases spread through shallow groundwater from hazard sources such as open defecation, latrines, waste dumps and burial sites to water supplies. The focus of this rapid desk study is to assess from existing literature the evidence for sub-surface transport of pathogens in the context of the hydrogeological and socio-economic environment of Sierra Leone. In particular, the outputs are to advise on the robustness of the evidence for an effective single minimum distance for lateral spacing between hazard sources and water supply, and provide recommendations for protecting water supplies for care facilities as well as other private and public water supplies in this region. Preliminary conclusions were: Considering the climate (heavy intense rainfall for 8 months), the hydrogeological conditions (prevalent shallow and rapidly fluctuating water tables, permeable tropical soils), the pervasive and widespread sources of hazards (very low improved sanitation coverage), and the widespread use of highly vulnerable water points there is little evidence that simply using an arbitrary lateral spacing between hazard sources and water point of 30 – 50 m would provide effective protection for groundwater points. An alternative framework that considers vertical as well as lateral separation and the integrity of the construction and casing of the deeper water points is recommended to protect water supplies from contamination by pathogens. The shallow aquifer, accessed by wells and springs, must be treated as highly vulnerable to pollution, both from diffuse sources and from localised sources. Diffuse pollution of groundwater from surface-deposited wastes including human excreta is likely to be at least as important as pollution from pit latrines and other point sources, given the low sanitation coverage in Sierra Leone. Even though conditions are not optimal for pathogen survival (e.g. temperatures of >25° C), given the very highly permeable shallow tropical soil zone, and the high potential surface and subsurface loading of pathogens, it is likely that shallow water sources are at risk from pathogen pollution, particularly during periods of intense rainfall and high water table conditions. Extending improved sanitation must be a high priority, in conjunction with improved vertical separation between hazard sources and water points, in order to reduce environmental contamination and provide a basis for improved public health. We recommend that risk assessments of water points are undertaken for health care facilities as soon as possible including: detailed sanitary inspections of water points within the 30 – 50 m radius suggested by the Ministry of Water Resource; assessments of the construction and integrity of the water points; a wider survey of contaminant load and rapid surface / sub surface transit routes within a wider 200 m radius of water points. Analysis of key water quality parameters and monitoring of water levels should be undertaken at each water point in parallel with the risk assessments. The translation of policy on water, sanitation and hygiene into implementation needs complementary research to understand key hydrogeological processes as well as barriers and failings of current practice for reducing contamination in water points. A baseline assessment of water quality status and sanitary risks for e.g. wells vs boreholes, improved vs unimproved sources in Sierra Leone is needed. Understanding the role of the tropical soil zone in the rapid migration of pollutants in the shallow subsurface, i.e. tracing rapid pathways, and quantifying residence times of shallow and deep groundwater systems are key knowledge gaps

In situ tryptophan-like fluorometers: assessing turbidity and temperature effects for freshwater applications

Tryptophan-like fluorescence (TLF) is an indicator of human influence on water quality as TLF peaks are associated with the input of labile organic carbon (e.g. sewage or farm waste) and its microbial breakdown. Hence, real-time measurement of TLF could be particularly useful for monitoring water quality at a higher temporal resolution than available hitherto. However, current understanding of TLF quenching/interference is limited for field deployable sensors. We present results from a rigorous test of two commercially available submersible tryptophan fluorometers (ex _ 285, em _ 350). Temperature quenching and turbidity interference were quantified in the laboratory and compensation algorithms developed. Field trials were then undertaken involving: (i) an extended deployment (28 days) in a small urban stream; and, (ii) depth profiling of an urban multi-level borehole. TLF was inversely related to water temperature (regression slope range: _1.57 to _2.50). Sediment particle size was identified as an important control on the turbidity specific TLF response, with signal amplification apparent 200 NTU for clay particles. Compensation algorithms significantly improved agreement between in situ and laboratory readings for baseflow and storm conditions in the stream. For the groundwater trial, there was an excellent agreement between laboratory and raw in situ TLF; temperature compensation provided only a marginal improvement, and turbidity corrections were unnecessary. These findings highlight the potential utility of real time TLF monitoring for a range of environmental applications (e.g. tracing polluting sources and monitoring groundwater contamination). However, in situations where high/ variable suspended sediment loads or rapid changes in temperature are anticipated concurrent monitoring of turbidity and temperature is required and site specific calibration is recommended for long term, surface water monitoring

A combined geochemical and hydrological approach for understanding macronutrient sources

This study employed complementary geochemical techniques and distributed hydrological modelling to investigate multiple sources of catchment macronutrients and characterise their changes in contrasting storm and baseflow conditions. This approach was demonstrated for the Beult catchment in the county of Kent (England), a designated Site of Special Scientific Interest (SSSI) indentified as failing to meet water quality standards for key nutrients under the Water Framework Directive. Significant changes in nutrient stoichiometry and bioavailability are observed for surface waters under contrasting flow regimes. Soluble reactive phosphorus (SRP) concentrations are approximately twice as high during baseflow compared to high flow, while the inverse is true for particulate, colloidal and dissolved hydrolysable phosphorus, dissolved organic carbon and nitrate. Nitrogen (N):phosphorus (P) ratios are lower during baseflow for most surface waters impacted by diffuse sources of pollution. Fluorescence indices of dissolved organic matter (DOM) show that waste water inputs may be locally important sources of more complex low molecular weight DOM, particularly during baseflow. Nitrate N and O isotope signatures, combined with other dissolved chemical tracers, confirm the dominance of wastewater N inputs at sites downsteam of sewerage treatment works during baseflow, with a shift towards the soil N pool in surface waters across the catchment during high flow. Distributed hydrological modelling using the Grid-to-Grid model reveal areas with the greatest runoff also export higher N and P concentrations, and hence deliver a greater flux of macronutrients, while forested areas with low nutrient concentrations reduce runoff and nutrient fluxes. During periods of high runoff, nested sampling indicates that nutrient fluxes scale with catchment area. This combined approach enables a more thorough assessment of the macronutrient sources and dynamics, better informing management options in nutrient impacted catchments

Development and initial application of δ18Op to understand phosphorus cycling in river, lake and groundwater ecosystems.

Variation in the stable isotope composition of oxygen within dissolved phosphate (δ18Op) represents a novel and potentially powerful environmental tracer. In freshwater, marine and terrestrial ecosystems, δ18Op can act as an inherent label for the sources of phosphorus and the extent to which phosphorus from different sources is metabolised. This paper focuses on the methodological development and initial application of δ18Op across a range of freshwater ecosystems. Initially, we report modifications to the analytical protocol for δ18Op that are designed to minimise incorporation of contaminant oxygen in the final silver phosphate precipitate prior to pyrolysis. This is critical given the range of possible sources of contaminant oxygen within freshwater matrices. Subsequently, we consider the potential utility of δ18Op through application of the technique within a range of freshwater ecosystems in England, UK. Firstly, we characterise δ18Op in river water and effluents from Sewage Treatment Works (STW), and examine the opportunity to use the 18Op of STW effluents to trace the entry and downstream fate of phosphorus from these point sources in rivers. Secondly, we analyse δ18Op to gain insights into variations in the sources and biological cycling of phosphorus in a seasonally stratified lake ecosystem. Thirdly, we characterise δ18Op in shallow and deep groundwater samples, considering whether δ18Op might provide evidence for variation in source and extent of metabolism for phosphorus in groundwater ecosystems. Taken together, these data extend the catalogue of δ18Op in freshwater ecosystems, and further the scope of δ18Op as a tool to better understand phosphorus biogeochemistry

Isotopic fingerprint for phosphorus in drinking water supplies

Phosphate dosing of drinking water supplies, coupled with leakage from distribution networks, represents a significant input of phosphorus to the environment. The oxygen isotope composition of phosphate (δ18OPO4), a novel stable isotope tracer for phosphorus, offers new opportunities to understand the importance of phosphorus derived from sources such as drinking water. We report the first assessment of δ18OPO4 within drinking water supplies. A total of 40 samples from phosphate-dosed distribution networks were analyzed from across England and Wales. In addition, samples of the source orthophosphoric acid used for dosing were also analyzed. Two distinct isotopic signatures for drinking water were identified (average = +13.2 or +19.7‰), primarily determined by δ18OPO4 of the source acid (average = +12.4 or +19.7‰). Dependent upon the source acid used, drinking water δ18OPO4 appears isotopically distinct from a number of other phosphorus sources. Isotopic offsets from the source acid ranging from −0.9 to +2.8‰ were observed. There was little evidence that equilibrium isotope fractionation dominated within the networks, with offsets from temperature-dependent equilibrium ranging from −4.8 to +4.2‰. While partial equilibrium fractionation may have occurred, kinetic effects associated with microbial uptake of phosphorus or abiotic sorption and dissolution reactions may also contribute to δ18OPO4 within drinking water supplies