Drivers of change in farming systems and forest cover in Ghana

Emmanuel Acheampong examined how Ghanaian farming practices influence farmers' livelihoods and forest cover. He found that farmers who adopt agricultural inputs are less likely to encroach forest reserves. Emmanuel hopes that Ghana's Forestry Commission and Ministry of Food and Agriculture will adopt his recommendations to enhance agricultural and forest sustainability

Remote Sensing for Management of Invasive Plants in Great Lakes Coastal Wetlands

Great Lakes coastal wetlands are some of the most crucial ecosystems to biodiversity in the Great Lakes Basin, yet suffer increasing degradation due to invasive plants. Wetland plant invasions can be controlled in their initial stages, but early detection of invasive plants using field surveys are often untenable due to budget constraints. Remote sensing techniques offer solutions to management objectives during the early stages of invasion on a landscape scale due to their ability to cheaply create spatially explicit information about plant distributions. Some invasive plants, such as Typha x. glauca, are conspicuous on a large scale, and can be mapped to their current extent using new satellite and modeling techniques. Inconspicuous invasive plants however, such as Hydrocharis morsus-ranae, may be undetectable by remote sensing sources and require predictive strategies. In this thesis I explored the use of remote sensing in the management of a conspicuous and inconspicuous invasive wetland plants in the St. Mary’s River, MI. I successfully classified the current extent of conspicuous Typha x. glauca and other wetland vegetation types to provide spatially explicit maps for early detection and management and examined methods that can be adapted for use in emergent wetlands worldwide. The habitat suitability of inconspicuous Hydrocharis morsus-ranae was also determined using novel fine-scale habitat covariates determined from lidar and radar. Habitat covariates derived from these sources should see wider use in species distribution modeling, particularly with wetland plants, to create better predictions of invasive plant expansions. Implementation of new and upcoming remote sensing data sources and methods will allow for better invasive wetland plant management at greater spatial and temporal scales than field studies alone

Complexity in Economic and Social Systems

There is no term that better describes the essential features of human society than complexity. On various levels, from the decision-making processes of individuals, through to the interactions between individuals leading to the spontaneous formation of groups and social hierarchies, up to the collective, herding processes that reshape whole societies, all these features share the property of irreducibility, i.e., they require a holistic, multi-level approach formed by researchers from different disciplines. This Special Issue aims to collect research studies that, by exploiting the latest advances in physics, economics, complex networks, and data science, make a step towards understanding these economic and social systems. The majority of submissions are devoted to financial market analysis and modeling, including the stock and cryptocurrency markets in the COVID-19 pandemic, systemic risk quantification and control, wealth condensation, the innovation-related performance of companies, and more. Looking more at societies, there are papers that deal with regional development, land speculation, and the-fake news-fighting strategies, the issues which are of central interest in contemporary society. On top of this, one of the contributions proposes a new, improved complexity measure

Synthetic glucocorticoids in the aquatic environment: their potential impacts on fish

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Human pharmaceuticals have been shown to be entering the aquatic environment in quantities sufficient to produce adverse effects to aquatic organisms, particularly fish. The impacts of synthetic oestrogens have been well documented, but other groups of steroidal pharmaceuticals have not yet been studied. Hence, the present research was designed to study synthetic glucocorticoids (GCs), which are used in large amounts as immunosuppressive and anti-inflammatory drugs. This study involved different approaches, including in silico, in vitro, in vivo and genomics, to assess the effects of GCs on fish. Using reliable data on consumption of GCs in the UK and the LF2000-WQX hydrological model, mean concentrations of GCs in the river Thames were predicted to be in the range from 30 ng/L to 850 ng/L. Mammalian cell lines were transiently transfected with trout corticosteroid receptors (GR1, GR2 and MR) and the transactivation abilities of ten of the most prescribed GCs in the UK were measured in vitro. All tested GCs showed significantly higher activity with GR2 than with GR1. In order to assess the impact of low concentrations of GCs in vivo, two chronic exposure experiments were conducted with adult fathead minnows (Pimephales promelas). Both experiments showed potency-related and concentration-related impacts on various endpoints. There was a concentration-related increase in plasma glucose concentrations and a decrease in blood lymphocyte count. Induction of secondary sexual characters in females suggests a concentration-related masculinisation of fathead minnows. There was a decreasing trend in plasma vitellogenin concentrations in female fish with increasing exposure concentration of GCs. Expression profiles of selected genes (PEPCK, GR and Vtg) in liver also demonstrated concentration-related effects at all three tested concentrations. Hence, it was not possible to define a no effect concentration for the tested GCs. This study probably provides reliable estimates of the likely range of concentrations of GCs in a typical river, impacted by effluent from many sewage treatment plants. The in vitro results indicate that all tested GCs bind to fish GR in a similar manner to that reported for mammalian receptors. The in vivo results suggest that GCs could cause effects at very low (as low as 100 ng/L) concentrations that could be environmentally-relevant. The immunosuppresive effects could make fish susceptible to disease and the reproductive effects may have population-level impacts. It is very likely that the effects of different GCs will be additive, as has been shown for oestrogenic chemicals. Therefore, this study warrants further environmental risk assessment of GCs, especially in mixture scenarios.Commonwealth Scholarship Commissio