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Methanogenic communities play a crucial role in carbon cycling and biotechnology (anaerobic digestion), but our understanding of how their diversity, or composition in general, determines the rate of methane production is very limited. Studies to date have been correlational because of the difficulty in cultivating their constituent species in pure culture. Here, we investigate the causal link between methanogenesis and diversity in laboratory anaerobic digesters by experimentally manipulating the diversity of cultures by dilution and subsequent equilibration of biomass. This process necessarily leads to the loss of the rarer species from communities. We find a positive relationship between methane production and the number of taxa, with little evidence of functional saturation, suggesting that rare species play an important role in methane‐producing communities. No correlations were found between the initial composition and methane production across natural communities, but a positive relationship between species richness and methane production emerged following ecological selection imposed by the laboratory conditions. Our data suggest methanogenic communities show little functional redundancy, and hence, any loss of diversity—both natural and resulting from changes in propagation conditions during anaerobic digestion—is likely to reduce methane production.

In this experiment, optimum experimental conditions for the enzymatic hydrolysis of grass at different stages of growth were obtained by using the Taguchi methodology. Rye grass silage and three growth stages of Italian rye grass samples were used to determine optimum hydrolysis conditions. Five factors (pretreatment, enzyme composition, incubation temperature, pretreatment time, pH) influencing the hydrolysis process were studied at the individual and interactive levels. All selected experimental factors influenced the hydrolysis of grass. At the individual level, pretreatment of grass with NaOH and enzyme composition had the greatest influence (75% and 14.7% of the variance respectively) on enzymatic hydrolysis. Incubation temperature, pretreatment time and pH had influences of 8.1%, 2.2% and 0.055%, respectively. pH and incubation temperature had the most significant interaction effect (65.6%) on enzymatic hydrolysis. The factors with the least individual influence had the most significant interaction effect on enzymatic hydrolysis. Hydrolysis was improved when optimised conditions were applied to different growth stages of Italian rye grass.

This thesis explores the role and functionality of the Hamilton Urban Core Community Health Centre (HUCCHC) within the context of advocacy and activism to understand how this institution can contribute a pathway for social change in public health. This qualitative case study uses an interpretive lens to analyze primary health care at the HUCCHC, and how it is being used to improve the social determinants of health (SDH). The study investigated participants’ understandings of how the HUCCHC demonstrates that a community health centre can be a catalyst for social change. Moreover, this research project asked what sorts of conditions or circumstances are necessary to foster an environment conducive for community organizing for social change. This study employed field observation and interview techniques to gather data. Findings suggest that building equitable relationships based on dignity and respect, and community engagement were the foundational aspects necessary to provide the conditions conducive for community organizing. However, the outcomes from these relations put the HUCCHC at risk of becoming marginalized. Findings further suggest that equitable relationships and community engagement also provided a foundation for social action. The HUCCHC demonstrated that it is a catalyst for social change by embracing a primary health care model that also fosters a social action approach to health care. Thesis Master of Social Work (MSW)

Expanding Anaerobic Digestion (AD) in the UK will not only depend upon finding appropriate economic structures to support on‐farm developments but also an appreciation of environmental issues such as less Greenhouse Gas (GHG) emissions; reduced use of artificial fertilisers; and better management of farm wastes. At the core of this paper is the Anaerobic Digestion Analytical Model (ADAM) that examines the economic and environmental impacts of integrating AD into UK farming systems. However, the average dairy farm in the UK is not of sufficient size to enable profitable biogas production. Indeed, farm size, as represented by FBS/FAS data used in ADAM, needs to be scaled by three to four times for a biogas enterprise to break‐even. To boost profitability, some farms may use additional energy (food and non food) crops as well as other high energy sources such as biodiesel residues etc. In some circumstances, possibilities may exist for neighbouring farmers to co‐operate and manage a biogas installation that processes manures and energy crops to increase the scale of an on‐farm plant. Despite issues of scale however, on‐farm AD plants do have the capacity to (i) reduce Carbon Dioxide equivalent (CO2e) emissions that a dairy farm produces; and (ii) the by‐product of digestate provides farms with greater nutrient availability for crops.