Modelling the response of a highly eutrophic lake to reductions in external and internal nutrient loading

The reduction of macronutrients to levels that limit primary production is often a critical element of mitigating eutrophication and reducing the potential for algal blooms. Lake Okaro has remained highly eutrophic despite an intensive catchment and in-lake restoration programme, including implementation of a constructed wetland, riparian protection, an alum application and application of a modified zeolite mineral (Z2G1) to reduce internal nutrient loading. A one-dimensional process-based ecosystem model (DYRESM-CAEDYM) was used in this study to investigate the need for further nutrient loading reductions of both nitrogen (N) and phosphorus (P). The model was calibrated against field data for a 2-year period and validated over two separate 1-year periods. Model simulations suggest that the trophic status of the lake, measured quantitatively with the Trophic Level Index (TLI), could shift from highly eutrophic to mesotrophic with external and internal loads of both N and P reduced by 75-90%. The magnitude of the nutrient load reductions is indicative of a major challenge in being able to effect transitions across trophic state categories for eutrophic lakes

Evaluating the influence of lake morphology, trophic status and diagenesis on geochemical profiles in lake sediments

Recent geochemical studies provide evidence that changes in vertical distributions of nutrients in lake sediments are driven by anthropogenic activities, based primarily on trends of increasing concentrations in upper sediment layers. However, we show that vertical concentration profiles of carbon (C), nitrogen (N) and phosphorus (P) in lake sediments can be higher in the upper, most recently deposited sediment strata, driven largely by natural diagenetic processes and not eutrophication alone. We examined sediment cores from 14 different lakes in New Zealand and China ranging from oligotrophic to highly eutrophic and shallow to deep, and found that the shape of vertical profiles of total P, a key nutrient for lake productivity, can be similar in sediments across gradients of widely differing trophic status. We derived and applied empirical and mechanistic diagenesis steady state profile models to describe the vertical distribution of C, N and P in the sediments. These models, which focus on large scale temporal (decades) and spatial (up to 35 cm in the vertical) processes, revealed that density-differentiated burial and biodiffusive mixing, were strongly correlated with vertical concentration gradients of sediment C, N and P content, whereas lake trophic status was not. A sensitivity analysis of parameters included in the diagenetic model further showed that the processes including flux of organic matter to the sediment-water interface, burial (net sedimentation), breakdown of organic matter and biodiffusion all significantly can influence the vertical distribution of sediment P content. We conclude that geochemical studies attempting to evaluate drivers of the vertical distribution of sediment C, N, and P content in lake sediments should also account for the natural diagenetic drivers of vertical concentration gradients, assisted with application of similar models to those presented in this study. This would include quantification of key sediment diagenesis model parameters to separate out the influence of anthropogenic activities

Leslie Tapson in a Sophomore Recital

This is the program for the sophomore voice recital of Leslie Tapson, accompanied by Pam Dennis on the piano and assisted by Craig Hamilton on trumpet. The recital was held on March 4, 1994, in the Mabee Fine Arts Center\u27s Recital Hall

Analysis of Limiting Factors Across the Life Cycle of Delta Smelt (Hypomesus transpacificus)

We developed a mechanistic life-cycle model derived from the elicitation of multiple factors influencing the success of individual life-stages of the imperiled delta smelt (Hypomesus transpacificus). We discuss the relevance of limiting factors in population ecology and problems with additive models in detecting them. We identify limiting factors and assess their significance using a non-linear optimization routine, combined with traditional metrics to assess the value of covariates and model performance. After reviewing previous conceptual models and multivariate analyses, we identified a set of factors that were consistent with conceptual models and useful in explaining the erratic fluctuations in a common abundance index: food at certain times in certain locations, predation by introduced species primarily in the spring, and entrainment. The analytical approach provides a transparent and intuitive framework in which to consider the contribution of covariates and consequences for population trends, and has the potential to assist with the evaluation of proposed recovery measures

David Dennis, Craig Hamilton, and Darrell Watts in a Joint Recital

This program is for the recital of pianist David Dennis, trumpet player Craig Hamilton, and bass trombone player Darrell Watts. The recital took place on September 24, 1987, in the Mabee Fine Arts Center Recital Hall

The calculation of embodied energy in new build UK housing

Reducing CO2 emissions to mitigate the impacts of climate change is now an international imperative. The built environment is responsible for nearly half of all CO2 emissions in the UK. Therefore, the reduction of carbon emissions from the products and processes involved in a building’s lifecycle are of paramount importance in meeting national and global emissions reduction targets. The energy used and consequent carbon emissions associated with construction materials and processes are usually calculated using the concept of embodied energy, albeit with significant variations in methodology. In general, the embodied energy of a building is considered to account for less than one-fifth of its whole-life energy use. However, as energy efficiency for new-build improves towards the zero carbon target in 2016, the embodied energy will assume an increasingly greater proportion, approaching 100% of the lifetime energy use and emissions. The research reported here is aimed at achieving a better understanding of the aspects of embodied energy of new-build UK houses (in particular, the focus is on the accuracy of various calculation procedures) that are often simplified to a few building types via a generalised and frequently non- UK, representation of the construction process. The need for a more standardised calculation method for embodied energy and resulting CO2 emissions is therefore discussed. Although considered in relation to the house building industry, this research is also applicable to the wider construction industry, as well as manufacturing

Superoscillation in speckle patterns

Waves are superoscillatory where their local phase gradient exceeds the maximum wavenumber in their Fourier spectrum. We consider the superoscillatory area fraction of random optical speckle patterns. This follows from the joint probability density function of intensity and phase gradient for isotropic gaussian random wave superpositions. Strikingly, this fraction is 1/3 when all the waves in the two-dimensional superposition have the same wavenumber. The fraction is 1/5 for a disk spectrum. Although these superoscillations are weak compared with optical fields with designed superoscillations, they are more stable on paraxial propagation.Comment: 3 pages, two figures, Optics Letters styl

Too hot to handle: African Caribbean pupils and students as toxic consumers and commodities in the educational market

This is an accepted manuscript of an article published by Taylor & Francis on 21/09/2017, available online: https://doi.org/10.1080/13613324.2017.1376635 The accepted version of the publication may differ from the final published version.Secondary sources are used in this paper to highlight how African Caribbean pupils and students – the Black British-born descendants of post-war Caribbean migrants – are victims of symbolic violence, because they are denied the educational capital needed to improve their social status. Since African Caribbean children entered the 1960s British educational sector, their learning has been perceived as problematic by the State. Although assimilation, integration and multicultural education policies were implemented to supposedly address the ‘problem’ of educating Black children, subsequent government reports identified racism as a significant barrier in their education. I argue here that the contemporary marketisation of education makes it increasingly difficult to distinguish between racism and competition, as causal factors of ethnic differences in educational attainment. Moreover, due to increasing private sector intervention and decreasing mediation by the State, racism is now hidden within the vicissitudes of the educational market. School exclusions and discriminatory practices in universities are viewed in this paper as major barriers to the economic success and future social mobility of Black Caribbean pupils and students. I conclude by suggesting that marketisation policies can be appropriated to ameliorate racism in education, but only if the political will to do so exists

Union black : the social and spatial mobility of African Caribbeans in Birmingham, UK.

This thesis explores the impact that legislative changes have had on African Caribbeans competing in Birmingham’s market situations. It also assesses the extent to which educational and labour market success or failure might have influenced their contemporary spatial locations. A mixed methods approach is utilised to examine how the social class position, and spatial patterns, of the city’s African Caribbean population have changed since the early 1980s. The research provides a contemporary update of aspects of Rex and Tomlinson’s (1979) survey, and also Ratcliffe’s (1981) work, which was conducted in 1970s Handsworth. Despite successive anti-discrimination legislation, passed between 1965 and 2010, racist practices in the education, employment and housing markets have persisted. African Caribbean social and spatial mobility are examined in the context of social, political and ideological changes influencing the equality agenda, particularly where racial inequality is concerned. Shifts in the educational and labour market status of Black Caribbeans are articulated using Marxian, Weberian and Bourdieusian notions of social classes: as position, as situation and as disposition, respectively. Social mobility is measured according to the progress African Caribbeans have made in their efforts to obtain higher educational capital, and the extent to which they have exchanged them for occupations in the upper tiers of the labour market. African Caribbean spatial mobility is mapped between 1991 and 2011 and the movement of Birmingham’s Black population, from high to low deprivation urban spaces, is examined. Changes from renting to homeownership, are also analysed as indicators of improvement in Black Caribbean housing tenure. The critical race perspective, of interest convergence, is used to argue that the free market can be appropriated to ameliorate racism. However, it is also acknowledged that African Caribbean community organisations, and those sharing the same focal concerns, must pool their resources to achieve the aim of racial equity