Black Scoter (\u3ci\u3eMelanitta americana\u3c/i\u3e) Winter Habitat Use and Movement Patterns Along the Atlantic Coast of the United States

While the Atlantic coast of the United States and Canada is a major wintering area for sea ducks, habitat use and movement patterns of sea ducks, such as the black scoter (Melanitta americana), are vastly unknown and understudied. The lack of information in conjunction with a rise in human activity in and near the Atlantic Ocean has led to an increased effort for the conservation and management of sea ducks, while minimizing human conflicts. The objectives of my study were to 1) identify variables that had the most influence on black scoter distribution in the Atlantic Ocean along the southeastern coast of the United States and 2) investigate the winter movement patterns of black scoters in the Atlantic Ocean by quantifying the number of wintering sites, arrival and departure dates to and from the wintering grounds, days at a wintering site, area of a wintering site, distance between wintering site, and test if winter movement patterns varied by sex or geography. To identify the variables that were the most influential on black scoter distribution along the southeastern coast of the United States, I used aerial survey data from 2009 to 2012 provided by the United States Fish and Wildlife Service. I ran a Least Absolute Shrinkage and Selection Operator (LASSO) with broad and fine scale oceanographic and weather variables. The oceanographic variables of bathymetry, ocean floor slope, and distance to shore were found to have the greatest association with the distribution of black scoter. Additionally, my results suggest that oceanographic variables have a stronger relationship with black scoter distribution than weather variables. To quantify winter movement patterns of black scoters, I used satellite telemetry data from 2009 to 2012 that was provided by the Sea Duck Joint Venture. I used Mann-Whitney U-tests to quantify the differentiation between sex and geography. While there was no difference between sexes, average wintering site area and distance between wintering sites differed by geographic region. Southern wintering sites were larger and farther apart than northern wintering sites. These results suggest that black scoter habitat use and movement patterns vary regionally. My results enable managers to focus sampling effort for black scoter abundance and distribution along the Atlantic coast. Habitat characteristics for black scoters identified in my study area should be carefully considered when planning anthropogenic activities along the southeast coast of the United States, such as offshore energy development

Long-term impacts of mid-Holocene drier climatic conditions on Bolivian tropical dry forests

Dry forests are the most threatened tropical biome in South America, with only 10% of their original cover remaining. Chapter 1 reviews literature on tropical dry forests and palaeoecology to demonstrate why the impact of the drier climatic conditions predicted for much of South America in the coming century on these forests is uncertain. This thesis uses the mid-Holocene (6000 years BP) drier climatic period to provide insight into the long-term ecological responses of tropical dry forest to drier conditions. One of the reasons for uncertainty over the impacts of the mid-Holocene drier climate on these forests is the lack of large lakes from which to draw palaeoecological records. The large lakes that do exist within the dry forest biome in Bolivia are situated in complex catchments with hydrological connections to tropical wetlands. In this thesis we therefore first develop our understanding of a relatively new palaeoecological proxy –phytoliths –to assist in our interpretation of the mid-Holocene palaeo-vegetation record. Chapter 2 demonstrates the palaeoecological potential of phytoliths from lake sediments, including the first empirical evidence that phytoliths from lakes most strongly represent local vegetation. Chapter 3 builds on these findings to investigate the sensitivity of phytoliths to vegetation changes within key Bolivian ecosystems, and compares it to pollen, showing that phytoliths are most sensitive to changes within ecosystems with strong herbaceous components such as forest understories. Chapter 4 uses the results of the previous chapters to investigate the response of the Bolivian dry forest to mid-Holocene drier climatic conditions, demonstrating resilience of the dry forest as a biome, with a shift in composition towards more drought-tolerant taxa. However, savannah encroachment did occur at the ecotone during the mid-Holocene, with fire identified as potentially reinforcing the ecotone shift. The vulnerability of tropical dry forests to future climate change will therefore depend on complex interactions between climate, fire and human land-use

BRAVE: building understanding of climate variability into planning of groundwater supplies from low storage aquifers in Africa

The BRAVE project aims to reduce risk and improve water security resilience of rural communities in the Sahel region of Africa by combining better understanding and planning of groundwater supplies with practical communication and knowledge exchange at all levels, from individual smallholder farmers to national government and regional bodies. The BRAVE project takes an interdisciplinary approach to integrate information on livelihoods and vulnerability with physical modelling of land surface and groundwater. Our improved understanding of how water moves through catchments in the Sahel and the resilience of supplies to climate variability and change, combined with information on vulnerability of different groups in the community, has enabled the project to create contextually applicable planning and monitoring tools. These tools support sustainable investment in groundwater and unlock the potential of this valuable water source. The BRAVE project is part of the UPGro consortium who produced a film communicating the consortium’s findings: http://www.walker.ac.uk/about-walker/news-events/upgro- film-unlocking-af ricas-groundwater-potential/ How the project is supporting the COP26 priorities In the Sahel region, rainfall is projected to become increasingly erratic with climate change. Alternative, more reliable water sources are required to support poverty reduction and rural development. The region contains large volumes of water underground, in groundwater aquifers, which may be enhanced by more intense rainfall events. The BRAVE project aims to develop tools to support evidence-based, sustainable and contextually relevant management of this groundwater resource, and communicate these with stakeholders at all levels, from small holder farming communities, to district planning officers and national policy makers. This will be vital for supporting adaptation and resilience to climate impacts in the region. This is directly relevant to the first COP26 priority stated by Alok Sharma MP in his speech to UN member states on 8 March 2020: “First, adaptation and resilience. Helping people, economies and the environment adapt and prepare for the impacts of climate change.” Impact The BRAVE project has supported increased evidence-based decision making on groundwater resource use and planning at multiple levels. Strong relationships with stakeholders in national government and the Coalition of NGOs in Water and Sanitation (CONIWAS) has been critical to these impacts. At the transboundary level, BRAVE findings on groundwater, poverty and water resource access were used to inform the White Volta Basin Authority’s Integrated Water Resource Management plans. At the national level, engagement with CONIWAS in Ghana resulted in a request from parliamentarians to establish an intersectoral committee on groundwater. In Ghana and Burkina Faso, national policy makers attended scenario planning workshops on climate change and groundwater. In Burkina Faso, these scenarios will inform the development of the National Adaptation Plan for the Water Sector. At the community level, farmer-led radio programmes have provided accessible, relevant information to farmers, supporting ground-level changes that improve their climate resilience

Rare disease prevention and treatment:The need for a level playing field

Pharmacogenetic tests are being used increasingly to prevent rare and potentially life-threatening adverse drug reactions. For many tests, however, cost–effectiveness is hard to demonstrate, and with the exception of a few cases, widespread implementation remains a distant prospect. Many orphan drugs for rare diseases are also not cost effective but are nonetheless normally reimbursed. In this article, we argue that the health technology assessment of pharmacogenetic tests aimed to prevent rare but severe adverse drug reactions should be on a level playing field with orphan drugs. This is supported by a number of arguments, concerning the severity, rarity and iatrogenic nature of adverse drug reactions, the distribution of benefits and costs and societal preference towards prevention over treatment. </jats:p

Linear mixed models to handle missing at random data in trial-based economic evaluations

Trial-based cost-effectiveness analyses (CEAs) are an important source of evidence in the assessment of health interventions. In these studies, cost and effectiveness outcomes are commonly measured at multiple time points, but some observations may be missing. Restricting the analysis to the participants with complete data can lead to biased and inefficient estimates. Methods, such as multiple imputation, have been recommended as they make better use of the data available and are valid under less restrictive Missing At Random (MAR) assumption. Linear mixed effects models (LMMs) offer a simple alternative to handle missing data under MAR without requiring imputations, and have not been very well explored in the CEA context. In this manuscript, we aim to familiarize readers with LMMs and demonstrate their implementation in CEA. We illustrate the approach on a randomized trial of antidepressants, and provide the implementation code in R and Stata. We hope that the more familiar statistical framework associated with LMMs, compared to other missing data approaches, will encourage their implementation and move practitioners away from inadequate methods