Emergy Evaluations of Denmark and Danish Agriculture Assessing the Limits of Agricultural Systems to Power Society

As the process of industrialization has run its course over the twentieth century, the relative importance of agriculture as an economic activity and a means of cultural sustenance for nations has declined dramatically. In this thesis, a historical ecological-economic perspective offers insights into both the causes and effects of Danish agriculture's decline in economic importance relative to the economy of Denmark as a whole. Emergy evaluations were made of the national economy and agricultural subsystem of Denmark for the years 1936, 1970 and 1999. Emergy is defined as all the available energy that was used in the work of making a product and expressed in units of one type of energy (Odum, 1996). In total, six separate emergy analyses were performed. By quantifying the emergy requirements of both a national agricultural system and the economy within which this system is nested, the analysis highlights the changing relationship of these two systems over a temporal scale of 63 years. The ecological sustainability of the studied systems is assessed through the calculation of emergy-based indices and ratios. In accordance with emergy theory, ecological sustainability is considered to be a function of the dependence of a system on renewable emergy, the degree to which the system depends on imported emergy, and the overall load that the system places on the environment. The analysis indicates that as the national economy of Denmark evolved to rely more on the use of non-renewable emergy and on emergy appropriated through trade to stimulate economic activity and to generate wealth, its sustainability declined, and the importance of the Danish agricultural system to the national economy subsided. While the total amount of emergy supporting the economy of Denmark over the period studied increased substantially, the total emergy supporting agriculture remained relatively constant. Furthermore, though the emergy signature and thermodynamic efficiencies of Danish agricultural production changed significantly, the total emergy required for production fluctuated little. This implies that the thermodynamically optimal level of emergy investment to agricultural production from society may fall within a range that is essentially fixed. Finally, the analysis draws attention to the fact that because agricultural systems are coupled to renewable emergy flows that are limited in the amount of work processes that they can power, agricultural systems register small net emergy yields, thus, agriculture is not likely to be a primary motive force in an economy with access to storages of fossil and other fuels that provide large net emergy yields

Farmers’ perceptions of climate change : identifying types

Ambitious targets to reduce greenhouse gas (GHG) emissions from agriculture have been set by both national governments and their respective livestock sectors. We hypothesize that farmer self-identity influences their assessment of climate change and their willingness to im- plement measures which address the issue. Perceptions of climate change were determined from 286 beef/sheep farmers and evaluated using principal component analysis (PCA). The analysis elicits two components which evaluate identity (productivism and environmental responsibility), and two components which evaluate behavioral capacity to adopt mitigation and adaptation measures (awareness and risk perception). Subsequent Cluster Analyses reveal four farmer types based on the PCA scores. ‘The Productivist’ and ‘The Countryside Steward’ portray low levels of awareness of climate change, but differ in their motivation to adopt pro-environmental behavior. Conversely, both ‘The Environmentalist’ and ‘The Dejected’ score higher in their awareness of the issue. In addition, ‘The Dejected’ holds a high sense of perceived risk; however, their awareness is not conflated with an explicit understanding of agricultural GHG sources. With the exception of ‘The Environmentalist’, there is an evident disconnect between perceptions of agricultural emission sources and their contribution towards GHG emissions amongst all types. If such linkages are not con- ceptualized, it is unlikely that behavioral capacities will be realized. Effective communication channels which encour- age action should target farmers based on the groupings depicted. Therefore, understanding farmer types through the constructs used in this study can facilitate effective and tai- lored policy development and implementation

Attempted use of PACE for riboswitch discovery generates three new translational theophylline riboswitch side products

Abstract Objective The purpose of this project was to use an in vivo method to discover riboswitches that are activated by new ligands. We employed phage-assisted continuous evolution (PACE) to evolve new riboswitches in vivo. We started with one translational riboswitch and one transcriptional riboswitch, both of which were activated by theophylline. We used xanthine as the new target ligand during positive selection followed by negative selection using theophylline. The goal was to generate very large M13 phage populations that contained unknown mutations, some of which would result in new aptamer specificity. We discovered side products of three new theophylline translational riboswitches with different levels of protein production. Results We used next generation sequencing to identify M13 phage that carried riboswitch mutations. We cloned and characterized the most abundant riboswitch mutants and discovered three variants that produce different levels of translational output while retaining their theophylline specificity. Although we were unable to demonstrate evolution of new riboswitch ligand specificity using PACE, we recommend careful design of recombinant M13 phage to avoid evolution of “cheaters” that short circuit the intended selection pressure