I\u27ll Live For You Or Die

https://digitalcommons.library.umaine.edu/mmb-vp/3796/thumbnail.jp

Squirrelpox virus: assessing prevalence, transmission and environmental degradation

Red squirrels (Sciurus vulgaris) declined in Great Britain and Ireland during the last century, due to habitat loss and the introduction of grey squirrels (Sciurus carolinensis), which competitively exclude the red squirrel and act as a reservoir for squirrelpox virus (SQPV). The disease is generally fatal to red squirrels and their ecological replacement by grey squirrels is up to 25 times faster where the virus is present. We aimed to determine: (1) the seropositivity and prevalence of SQPV DNA in the invasive and native species at a regional scale; (2) possible SQPV transmission routes; and, (3) virus degradation rates under differing environmental conditions. Grey (n = 208) and red (n = 40) squirrel blood and tissues were sampled. Enzyme-linked immunosorbent assay (ELISA) and quantitative real-time polymerase chain reaction (qPCR) techniques established seropositivity and viral DNA presence, respectively. Overall 8% of squirrels sampled (both species combined) had evidence of SQPV DNA in their tissues and 22% were in possession of antibodies. SQPV prevalence in sampled red squirrels was 2.5%. Viral loads were typically low in grey squirrels by comparison to red squirrels. There was a trend for a greater number of positive samples in spring and summer than in winter. Possible transmission routes were identified through the presence of viral DNA in faeces (red squirrels only), urine and ectoparasites (both species). Virus degradation analyses suggested that, after 30 days of exposure to six combinations of environments, there were more intact virus particles in scabs kept in warm (25°C) and dry conditions than in cooler (5 and 15°C) or wet conditions. We conclude that SQPV is present at low prevalence in invasive grey squirrel populations with a lower prevalence in native red squirrels. Virus transmission could occur through urine especially during warm dry summer conditions but, more notably, via ectoparasites, which are shared by both species

Groundwater : meltwater interaction in a proglacial aquifer

Groundwater plays a significant role in the hydrology of active glacial catchments, with evidence that it may buffer changes in meltwater river flow and partially compensate for glacial loss. However, to date there has been little direct research into the hydrogeology and groundwater dynamics of proglacial aquifers. Here we directly investigate the three dimensional nature of a proglacial sandur (floodplain) aquifer in SE Iceland, using hydrogeological, geophysical, hydrological and stable isotopic techniques, and provide evidence of groundwater-melt water dynamics over three years. We show that the proglacial sandur forms a thick (at least 50-100 m), high permeability (transmissivity up to 2500 m2/day) aquifer, extending over an area of approximately 6 km2. At least 35 million m3 of groundwater is stored in the aquifer, equivalent to ~23-28% of total annual river flow through the catchment. The volume of mean annual groundwater flow through the aquifer is at least 0.1-1 m3/sec, equivalent to ~10-20% of mean annual river flow. Groundwater across the aquifer is actively recharged from local precipitation and strongly influenced by individual rainfall events and seasonal precipitation. Glacial meltwater influence on groundwater also occurs in a zone extending from 20-500 m away from the meltwater river, for at least 3km down-sandur, and to at least 15 m deep. Within this zone summer recharge from the river to groundwater occurs when meltwater river flows are high, maintaining high summer groundwater levels compared to winter levels; and groundwater temperature and chemistry are strongly influenced by meltwater. Beyond this zone there is no substantial meltwater influence on groundwater. From ~2 km down-sandur there is extensive groundwater discharge via springs, supporting semi-perennial streams that form distinct local ecosystems, and providing baseflow to the main meltwater river. This research indicates that predicted continued climate change-related reductions in glacier coverage and increases in precipitation are likely to increase the significance of groundwater storage as a water resource, and of groundwater discharges in maintaining environmental river flows in glacier catchments

Novel imaging tools for investigating the role of immune signalling in the brain

Abstract not availableJonathan Henry W. Jacobsen, Lindsay M. Parker, Arun V. Everest-Dass, Erik P. Schartner, Georgios Tsiminis, Vasiliki Staikopoulos, Mark R. Hutchinson, Sanam Mustaf

Squirrelpox in a red squirrel in Fife

SQUIRRELPOX has been identified as a key factor in red squirrel (Sciurus vulgaris) decline in the UK.1 Grey squirrels (Sciurus carolinensis) are thought to act as reservoir hosts for squirrelpox virus (SQPV), the causative agent of squirrelpox, with a reported asymptomatic seroprevalence of 61 per cent.2SQPV is implicated in the complete replacement of red squirrels by grey squirrels throughout mainland England and Wales,1 and poses a major threat to Scottish red squirrel populations since being first detected in 2007.3 To combat this threat, an mortality surveillance programme has been established at the Royal (Dick) School of Veterinary Studies, University of Edinburgh, using opportunistic sampling of red squirrel carcases. This has been ongoing for several years, including a summary publication covering 262 cases submitted from 2005 to 2009.4As part of this monitoring programme, an adult female red squirrel carcase was submitted by a member of the public, after having been found in Townhall Wood (NT110894), on the outskirts of Dunfermline, Fife, in March 2024. Postmortem examination identified multiple lesions typically associated with squirrelpox, including ulcerative and exudative dermatitis of the periocular and perioral skin (Fig 1). Histopathology of the affected skin identified extensive ulceration alongside remnant areas of epithelium with marked ballooning degeneration and eosinophilic intracytoplasmic inclusion bodies. Transmission electron microscopy of the affected tissue also identified numerous pox virions within the affected tissue, which through their size, shape and available surface morphology (Fig 2), were consistent with those of SQPV. In Britain there have been no additional identified diseases in red squirrels that present with periocular or perioral, ulcerative to exudative dermatitis due to a poxvirus,5indicating this case is highly likely due to SQPV.This finding represents the first identification of squirrelpox north of the central belt and is consistent with the predictions of previous modelling, which identified a high risk of northern SQPV spread from 2023 onwards.6 This modelling also suggests a rapid increase and spread of squirrelpox into more northerly and naive red squirrel populations is likely following establishment north of the central belt in central Scotland.6This case and modelling supports an increased requirement for targeted investigations, ongoing monitoring and grey squirrel interventions both around Dunfermline itself and within adjacent areas to establish the disease burden in this locality and limit further northerly squirrelpox spread.LA Wilson, veterinary pathology lecturer, M Marr, postdoctoral research fellow, C Logie, postmortem room technician, K Beckmann, conservation medicine lecturer, PWW Lurz, squirrel ecologist, R Ogden, director of conservation science, E Milne, professor emerita of veterinary clinical pathology Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian EH25 9RG email: [email protected] DJ Everest, pathology scientist APHA Weybridge, Addlestone, Surrey KT15 3NBReferences1 Tompkins DM, White AR, Boots M. Ecological replacement of native red squirrels by invasive greys driven by disease. Ecol Lett2003;6:189–962 Sainsbury AW, Nettleton P, Gilray J, et al. Grey squirrels have high seroprevalence to a parapoxvirus associated with deaths in red squirrels. Anim Conserv2000;3:229–33 3 Mclnnes CJ, Coulter L, Dagleish MP, et al. First cases of squirrelpox in red squirrels (Sciurus vulgaris) in Scotland. Vet Rec2009;164:528–314 LaRose JP, Meredith AL, Everest DJ, et al. Epidemiological and postmortem findings in 262 red squirrels (Sciurus vulgaris) in Scotland, 2005 to 2009. Vet Rec2010;167:297–3025 Everest DJ, Tolhurst-Cherriman DAR, Davies H, et al. Assessing a potential non-invasive method for viral diagnostic purposes in European squirrels. Hystrix 2019;30:44–506 White A, Lurz PWW. A modelling assessment of control strategies to prevent/reduce squirrelpox spread. 2014. Scottish Natural Heritage Commissioned Report No 627. https://bit.ly/441TOgM (accessed 8 April 2024)PROFESSIONHistory of the veterinary professionI WRITE in response to the debate article by Bruce Vivash Jones (VR, 16/23 March 2024, vol 194, p 236). As a PhD researcher on the history of the RCVS and veterinary regulation, and a veterinary nurse, I would like to raise some issues with Vivash Jones’ historical evidence. He states that changes to the council structure would create an oligarchy. From his interpretation of an oligarchy I can assure him and our profession that the first RCVS council did work as This finding represents the first identification of squirrelpox north of the central belt20/27 April 2024 | VET RECORD312Fig 2: Squirrelpox virus virions detected in the affected tissue. Bar = 200 nmFig 1: Macroscopic lesions of ulcerative and exudative dermatitis surrounding the eye in a red squirrel (Sciurus vulgaris)Letters 20 April.indd 312Letters 20 April.indd 31216/04/2024 12:4816/04/2024 12:4

Future evolution and uncertainty of river flow regime change in a deglaciating river basin

The flow regimes of glacier-fed rivers are sensitive to climate change due to strong climate–cryosphere–hydrosphere interactions. Previous modelling studies have projected changes in annual and seasonal flow magnitude but neglect other changes in river flow regime that also have socio-economic and environmental impacts. This study employs a signature-based analysis of climate change impacts on the river flow regime for the deglaciating Virkisá river basin in southern Iceland. Twenty-five metrics (signatures) are derived from 21st century projections of river flow time series to evaluate changes in different characteristics (magnitude, timing and variability) of river flow regime over sub-daily to decadal timescales. The projections are produced by a model chain that links numerical models of climate and glacio-hydrology. Five components of the model chain are perturbed to represent their uncertainty including the emission scenario, numerical climate model, downscaling procedure, snow/ice melt model and runoff-routing model. The results show that the magnitude, timing and variability of glacier-fed river flows over a range of timescales will change in response to climate change. For most signatures there is high confidence in the direction of change, but the magnitude is uncertain. A decomposition of the projection uncertainties using analysis of variance (ANOVA) shows that all five perturbed model chain components contribute to projection uncertainty, but their relative contributions vary across the signatures of river flow. For example, the numerical climate model is the dominant source of uncertainty for projections of high-magnitude, quick-release flows, while the runoff-routing model is most important for signatures related to low-magnitude, slow-release flows. The emission scenario dominates mean monthly flow projection uncertainty, but during the transition from the cold to melt season (April and May) the snow/ice melt model contributes up to 23&thinsp;% of projection uncertainty. Signature-based decompositions of projection uncertainty can be used to better design impact studies to provide more robust projections.</p

Emergent kinetic constraints, ergodicity breaking, and cooperative dynamics in noisy quantum systems

Kinetically constrained spin systems play an important role in understanding key properties of the dynamics of slowly relaxing materials, such as glasses. Recent experimental studies have revealed that manifest kinetic constraints govern the evolution of strongly interacting gases of highly excited atoms in a noisy environment. Motivated by this development we explore which types of kinetically constrained dynamics can generally emerge in quantum spin systems subject to strong noise and show how, in this framework, constraints are accompanied by conservation laws. We discuss an experimentally realizable case of a lattice gas, where the interplay between those and the geometry of the lattice leads to collective behavior and time-scale separation even at infinite temperature. This is in contrast to models of glass-forming substances which typically rely on low temperatures and the consequent suppression of thermal activation

Using stable isotopes and continuous meltwater river monitoring to investigate the hydrology of a rapidly retreating Icelandic outlet glacier

Virkisjökull is a rapidly retreating outlet glacier draining the western flanks of Öræfajökull in SE Iceland. Since 2011 there have been continuous measurements of flow in the proglacial meltwater channel and regular campaigns to sample stable isotopes δ2H and δ18O from the river, ice, moraine springs and groundwater. The stable isotopes provide reliable end members for glacial ice and shallow groundwater. Analysis of data from 2011 to 2014 indicates that although ice and snowmelt dominate summer riverflow (mean 5.3–7.9 m3 s−1), significant flow is also observed in winter (mean 1.6–2.4 m3 s−1) due primarily to ongoing glacier icemelt. The stable isotope data demonstrate that the influence of groundwater discharge from moraines and the sandur aquifer increases during winter and forms a small (15–20%) consistent source of baseflow to the river. The similarity of hydrological response across seasons reflects a highly efficient glacial drainage system, which makes use of a series of permanent englacial channels within active and buried ice throughout the year. The study has shown that the development of an efficient year round drainage network within the lower part of the glacier has been coincident with the stagnation and subsequent rapid retreat of the glacier

The geomorphology of Svínafellsjökull and Virkisjökull-Falljökull glacier forelands, southeast Iceland

A detailed, 1:10,500-scale, surficial geology and glacial geomorphology map of Svínafellsjökull and Virkisjökull-Falljökull glacier forelands in southeast Iceland depicts the landsystem imprint of Holocene glacier fluctuations, volcanogenic outburst floods and recent (post-1990) climate-induced rapid ice-front retreat. The map is based on field survey data in combination with 2012 airborne LiDAR data, 2009–2012 terrestrial LiDAR data and 2007 colour aerial photography. The base digital elevation model (DEM) is compiled from an ice-cap wide airborne LiDAR dataset. The mapped glacial landforms are dominated by sequences of recessional moraines laid down in the mid-Holocene, the Little Ice Age, and the last ∼100 years; the state of landform preservation generally decreasing with age. Interspersed with glaciofluvial sedimentation associated with typical ice-marginal retreat sequences is key geomorphological evidence of high-magnitude volcanogenic outburst floods (jökulhlaups) associated with the eruptions of Öraefajökull in 1362 and 1727 CE. Ice-front retreat has accelerated since c.2005 leaving a rapidly evolving buried-ice landscape in front of Virkisjökull-Falljökull – including an ice-cored esker, a large ice-floored (supraglacial) lake, and numerous actively forming kettle holes and ice caverns. This map could act as a ‘reference frame’ for geomorphologists studying the temporal evolution of glacial landform-sediment assemblages undergoing rapid change