Hibernation ecology and population biology of the hazel dormouse

Detailed knowledge of the ecology and environmental conditions suitable for individual species across the landscape is vital for effective conservation measures. Similarly, understanding demographic factors that influence the structure of animal populations is crucial for understanding species trends. In this thesis, I explore one of the most interesting aspects that distinguishes the hazel dormouse (Muscardinus avellanarius) from other woodland small mammals - its ability to hibernate. Hibernation is a complex strategy with marked trade-offs that shapes the demography and structure of hazel dormouse populations and yet it is one of the least studied facets of their life cycle. Firstly, I introduce relevant background to the thesis. I evaluate different methods to locate hibernacula, investigate dormouse movements before hibernation, their behaviour as they prepare to face months of low activity at low temperatures and fewer foraging opportunities, to the point where they find a suitable place to build a nest to hibernate on the ground. I then examine population structure and estimate overwinter survival of different hazel dormouse populations. Using telemetry, I found that hazel dormice select hibernation sites within their autumnal home range. I investigate the impact of hibernation on body weight of hazel dormice and quantify rates of weight loss in wild animals. With the use of high-resolution airborne LiDAR derived canopy structure and topography, I develop novel models to characterise hazel dormouse hibernaculum locations and predict suitable locations across the landscape. I demonstrate that topography, sky view and canopy height can influence hibernaculum location selection. At the hibernaculum location, I demonstrate how hazel dormouse hibernation nests are built in a similar fashion to their summer nests and that they utilise a range of materials that are available in the immediate vicinity of the selected hibernation site. I quantify hazel dormouse overwinter survival of different populations and find that on average 0.36 (0.29 - 0.44, 95% Confidence Intervals (CI) of the population survives. My findings, based on the existing literature and evidence I collected in the field, suggests that hazel dormice are resourceful, able to cope with diverse habitat characteristics and resources. Conservation efforts should therefore focus on creating, managing and/or enhancing diversity within their habitat by promoting a varied canopy structure that is well connected and made up of assorted tree and shrub species of value to the hazel dormice in order to increase nesting and foraging opportunities through the seasons.People's Trust for Endangered Specie

Can information and alternatives to irregular migration reduce "backway" migration from The Gambia?

Irregular migration from West Africa to Europe across the Sahara and Mediterranean is extremely risky for migrants and a key policy concern. A cluster-randomized experiment with 3641 young men from 391 settlements in The Gambia is used to test three approaches to reducing risky migration: providing better information and testimonials about the risks of the journey, facilitating migration to a safer destination by providing information and assistance for migration to Dakar, and offering vocational skill training to enhance domestic employment opportunities. Current migration to Senegal was increased by both the Dakar facilitation and vocational training treatments, partially crowding out internal migration. The vocational training treatment reduced intentions to migrate the backway and the number of steps taken toward moving. However, the backway migration rate from The Gambia collapsed, even in the control group, resulting in no space for a treatment effect on irregular migration from any of the three interventions.preprintpublishe

ASYMMETRIC LEAVES1 regulates abscission zone placement in Arabidopsis flowers

BACKGROUND: The sepals, petals and stamens of Arabidopsis flowers detach via abscission zones formed at their boundaries with the underlying receptacle. The ASYMMETRIC LEAVES1 (AS1) MYB transcription factor plays a critical role in setting boundaries between newly formed leaf primordia and the shoot meristem. By repressing expression of a set of KNOTTED1-LIKE HOMEODOMAIN (KNOX) genes from developing leaf primordia, AS1 and its partner ASYMMETRIC LEAVES2 allow the patterning and differentiation of leaves to proceed. Here we show a unique role for AS1 in establishing the positions of the sepal and petal abscission zones in Arabidopsis flowers. RESULTS: In as1 mutant flowers, the sepal abscission zones are displaced into inverted V-shaped positions, leaving behind triangular stubs of tissue when the organs abscise. Movement of the petal abscission zones is also apparent. Abscission of the medial sepals is delayed in as1 flowers; loss of chlorophyll in the senescing sepals contrasts with proximal zones that remain green. AS1 has previously been shown to restrict expression of the KNOX gene, BREVIPEDICELLUS (BP), from the sepals. We show here that loss of BP activity in as1 flowers is sufficient to restore the positions of the sepal and petal abscission zones, the sepal-receptacle boundary of the medial sepals and the timing of their abscission. CONCLUSIONS: Our results indicate that AS1 activity is critical for the proper placement of the floral organ abscission zones, and influences the timing of organ shedding

Using high-resolution LiDAR-derived canopy structure and topography to characterise hibernaculum locations of the hazel dormouse

This is the final version. Available on open access from Springer via the DOI in this recordData availability: The data that support the findings of this study are available from the corresponding author, LG, upon reasonable request.The hazel dormouse is predominantly an arboreal species that moves down to the ground to hibernate in the autumn in temperate parts of its distributional ranges at locations not yet well understood. The main objective of this study is to test whether environmental characteristics surrounding hazel dormouse hibernacula can be identified using high-resolution remote sensing and data collected in situ. To achieve this, remotely sensed variables, including canopy height and cover, topographic slope, sky view, solar radiation and cold air drainage, were modelled around 83 dormouse hibernacula in England (n = 62) and the Netherlands (n = 21), and environmental characteristics that may be favoured by pre-hibernating dormice were identified. Data on leaf litter depth, temperature, canopy cover and distance to the nearest tree were collected in situ and analysed at hibernaculum locations in England. The findings indicated that remotely sensed data were effective in identifying attributes surrounding the locations of dormouse hibernacula and when compared to in situ information, provided more conclusive results. This study suggests that remotely sensed topographic slope, canopy height and sky view have an influence on hazel dormice choosing suitable locations to hibernate; whilst in situ data suggested that average daily mean temperature at the hibernaculum may also have an effect. Remote sensing proved capable of identifying localised environmental characteristics in the wider landscape that may be important for hibernating dormice. This study proposes that this method can provide a novel progression from habitat modelling to conservation management for the hazel dormouse, as well as other species using habitats where topography and vegetation structure influence fine-resolution favourability.People’s Trust for Endangered Species (PTES

A digital self-management intervention for adults with type 2 diabetes: Combining theory, data and participatory design to develop HeLP-Diabetes

Background Digital health interventions have potential to contribute to better health outcomes, better healthcare and lower costs. However, evidence for their effectiveness is variable. The development and content of digital health interventions are often not described in enough detail to enable others to replicate the research or improve on previous interventions. This has led to a call for transparent reporting of intervention content and development. Purpose To describe the development process and content of a digital self-management intervention for people with type 2 diabetes (HeLP-Diabetes) that has been found to achieve its target clinical outcome, the reduction of HbA1c, a measure of glycaemic control. Method We synthesised theory, data from existing research evidence and international guidelines, and new qualitative data from target users to identify the determinants of self-management and the content to be included in HeLP-Diabetes. Using an ongoing iterative participatory design approach the content of the intervention was written, produced, reviewed and changed. Conclusion It is possible to develop and transparently report self-management programmes for long-term conditions, which reflect current best evidence, theoretical underpinning and user involvement. We intend that reporting the development process and content will inform future digital intervention development

R534C mutation in hERG causes a trafficking defect in iPSC-derived cardiomyocytes from patients with type 2 long QT syndrome

Patient-specific cardiomyocytes obtained from induced pluripotent stem cells (CM-iPSC) offer unprecedented mechanistic insights in the study of inherited cardiac diseases. The objective of this work was to study a type 2 long QT syndrome (LQTS2)-associated mutation (c.1600C > T in KCNH2, p.R534C in hERG) in CM-iPSC. Peripheral blood mononuclear cells were isolated from two patients with the R534C mutation and iPSCs were generated. In addition, the same mutation was inserted in a control iPSC line by genome editing using CRISPR/Cas9. Cells expressed pluripotency markers and showed spontaneous differentiation into the three embryonic germ layers. Electrophysiology demonstrated that action potential duration (APD) of LQTS2 CM-iPSC was significantly longer than that of the control line, as well as the triangulation of the action potentials (AP), implying a longer duration of phase 3. Treatment with the IKr inhibitor E4031 only caused APD prolongation in the control line. Patch clamp showed a reduction of IKr on LQTS2 CM-iPSC compared to control, but channel activation was not significantly affected. Immunofluorescence for hERG demonstrated perinuclear staining in LQTS2 CM-iPSC. In conclusion, CM-iPSC recapitulated the LQTS2 phenotype and our findings suggest that the R534C mutation in KCNH2 leads to a channel trafficking defect to the plasma membrane.Fil: Mesquita, Fernanda C. P.. Universidade Federal do Rio de Janeiro; BrasilFil: Arantes, Paulo C.. Universidade Federal do Rio de Janeiro; BrasilFil: Kasai Brunswick, Tais H.. Universidade Federal do Rio de Janeiro; BrasilFil: Araujo, Dayana S.. Universidade Federal do Rio de Janeiro; BrasilFil: Gubert, Fernanda. Universidade Federal do Rio de Janeiro; BrasilFil: Monnerat, Gustavo. Universidade Federal do Rio de Janeiro; BrasilFil: Silva dos Santos, Danúbia. Universidade Federal do Rio de Janeiro; BrasilFil: Neiman, Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Leitão, Isabela C.. Universidade Federal do Rio de Janeiro; BrasilFil: Barbosa, Raiana A. Q.. Universidade Federal do Rio de Janeiro; BrasilFil: Coutinho, Jorge L.. National Institute Of Cardiology; BrasilFil: Vaz, Isadora M.. Pontificia Universidad Catolica de Parana; BrasilFil: dos Santos, Marcus N.. Universidade Federal do Rio de Janeiro; BrasilFil: Borgonovo, Tamara. Pontificia Universidad Catolica de Parana; BrasilFil: Cruz, Fernando E. S.. National Institute of Cardiology; BrasilFil: Miriuka, Santiago Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Medei, Emiliano H.. Universidade Federal do Rio de Janeiro; BrasilFil: Campos de Carvalho, Antonio C.. Universidade Federal do Rio de Janeiro; Brasil. National Institute of Cardiology; Brasil. National Institute for Science and Technology in Regenerative Medicine; BrasilFil: Carvalho, Adriana B.. Universidade Federal do Rio de Janeiro; Brasil. National Institute for Science and Technology in Regenerative Medicine; Brasi