Publications by authors named "Ashton I"

Seaweed farming in Europe is growing and may provide environmental benefits, including habitat provisioning, coastal protection, and bioremediation. Habitat provisioning by seaweed farms remains largely unquantified, with previous research focused primarily on the detrimental effects of epibionts, rather than their roles in ecological functioning and ecosystem service provision. We monitored the development and diversity of epibiont assemblages on cultivated sugar kelp (Saccharina latissima) at a farm in Cornwall, southwest UK, and compared the effects of different harvesting techniques on epibiont assemblage structure.

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Harmful algal blooms (HABs) intoxicate and asphyxiate marine life, causing devastating environmental and socio-economic impacts, costing at least $8bn/yr globally. Accumulation of phycotoxins from HAB phytoplankton in filter-feeding shellfish can poison human consumers, prompting harvesting closures at shellfish production sites. To quantify long-term intoxication risk from Dinophysis HAB species, we used historical HAB monitoring data (2009-2020) to develop a new modelling approach to predict Dinophysis toxin concentrations in a range of bivalve shellfish species at shellfish sites in Western Scotland, South-West England and Northern France.

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Rapid climate warming is altering Arctic and alpine tundra ecosystem structure and function, including shifts in plant phenology. While the advancement of green up and flowering are well-documented, it remains unclear whether all phenophases, particularly those later in the season, will shift in unison or respond divergently to warming. Here, we present the largest synthesis to our knowledge of experimental warming effects on tundra plant phenology from the International Tundra Experiment.

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Following the outbreak of severe acute respiratory syndrome coronavirus (SARS-CoV-2), airborne water droplets have been identified as the main transmission route. Identifying and breaking all viable transmission routes are critical to stop future outbreaks, and the potential of transmission by water has been highlighted. By modifying established approaches, we provide a method for the rapid assessment of the risk of transmission posed by fecally contaminated river water and give example results for 39 countries.

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The ocean is a sink for ~25% of the atmospheric CO emitted by human activities, an amount in excess of 2 petagrams of carbon per year (PgC yr). Time-resolved estimates of global ocean-atmosphere CO flux provide an important constraint on the global carbon budget. However, previous estimates of this flux, derived from surface ocean CO concentrations, have not corrected the data for temperature gradients between the surface and sampling at a few meters depth, or for the effect of the cool ocean surface skin.

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Shelf seas play an important role in the global carbon cycle, absorbing atmospheric carbon dioxide (CO) and exporting carbon (C) to the open ocean and sediments. The magnitude of these processes is poorly constrained, because observations are typically interpolated over multiple years. Here, we used 298500 observations of CO fugacity (fCO) from a single year (2015), to estimate the net influx of atmospheric CO as 26.

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In the version of this Article originally published, the following sentence was missing from the Acknowledgements: "This work was supported by the Norwegian Research Council SnoEco project, grant number 230970". This text has now been added.

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Advancing phenology is one of the most visible effects of climate change on plant communities, and has been especially pronounced in temperature-limited tundra ecosystems. However, phenological responses have been shown to differ greatly between species, with some species shifting phenology more than others. We analysed a database of 42,689 tundra plant phenological observations to show that warmer temperatures are leading to a contraction of community-level flowering seasons in tundra ecosystems due to a greater advancement in the flowering times of late-flowering species than early-flowering species.

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The need to ensure future food security and issues of varying estuarine water quality is driving the expansion of aquaculture into near-shore coastal waters. It is prudent to fully evaluate new or proposed aquaculture sites, prior to any substantial financial investment in infrastructure and staffing. Measurements of water temperature, salinity and dissolved oxygen can be used to gain insight into the physical, chemical and biological water quality conditions within a farm site, towards identifying its suitability for farming, both for the stock species of interest and for assessing the potential risk from harmful or toxic algae.

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The global oceans are considered a major sink of atmospheric carbon dioxide (CO2). Rain is known to alter the physical and chemical conditions at the sea surface, and thus influence the transfer of CO2 between the ocean and atmosphere. It can influence gas exchange through enhanced gas transfer velocity, the direct export of carbon from the atmosphere to the ocean, by altering the sea skin temperature, and through surface layer dilution.

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Two sources of complexity make predicting plant community response to global change particularly challenging. First, realistic global change scenarios involve multiple drivers of environmental change that can interact with one another to produce non-additive effects. Second, in addition to these direct effects, global change drivers can indirectly affect plants by modifying species interactions.

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We conducted single- and mixed-litter experiments in a hardwood forest in Long Island, New York, using leaf litter from phylogenetically paired native and invasive species. We selected long-established, abundant invasive species with wide-ranging distributions in the eastern United States that likely make substantial contributions to the litter pool of invaded areas. Overall, leaf litter from invasive species differed from native litter, though differences varied by phylogenetic grouping.

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Niche complementarity, in which coexisting species use different forms of a resource, has been widely invoked to explain some of the most debated patterns in ecology, including maintenance of diversity and relationships between diversity and ecosystem function. However, classical models assume resource specialization in the form of distinct niches, which does not obviously apply to the broadly overlapping resource use in plant communities. Here we utilize an experimental framework based on competition theory to test whether plants partition resources via classical niche differentiation or via plasticity in resource use.

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Plant resource partitioning of chemical forms of nitrogen (N) may be an important factor promoting species coexistence in N-limited ecosystems. Since the microbial community regulates N-form transformations, plant partitioning of N may be related to plant-soil feedbacks. We conducted a (15)N tracer addition experiment to study the ability of two alpine plant species, Acomastylis rossii and Deschampsia caespitosa, to partition organic and inorganic forms of N.

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Introduction: An outbreak of echovirus meningitis occurred in the north west of England in 2001. This paper reviewed the clinical features and the role of different diagnostic methods.

Methods: This was a prospective study of adults admitted to a regional infectious disease unit with a probable diagnosis of meningitis, March to August 2001.

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Autologous chondrocyte implantation (ACI) for the treatment of articular cartilage defects has been described by other workers, however, relatively few details of the in vitro growth of the cells have been published. Here we describe the release of cells from adult human articular cartilage and their growth characteristics in vitro.Cultures were successfully established from 29 of 30 biopsies taken from patients aged 20-72 year.

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The aim of this project was to produce guidance for a rationalised virological electron microscopy specimen testing policy for PHLS North West, to facilitate centralisation of a groupwide diagnostic electron microscopy service on a single site. Careful specimen selection to limit numbers and the groupwide use of commercially available enzyme immunoassays has allowed PHLS North West to reduce the number of specimens prepared for electron microscopy. The rationalised virological electron microscopy specimen testing policy has enabled a diagnostic electron microscopy service to be provided from a single site with a manageable workload.

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Modulation of the respiratory burst activity of head kidney macrophages isolated from rainbow trout (Oncorhynchus mykiss) was observed following treatment with several biologically active substances. Macrophage-activating factor (MAF) induced the highest increment if respiratory burst activity relative to treatment with lipopolysaccharide (LPS), tumor necrosis factor alpha (TNF alpha) or beta-glucans from Saccharomyces cerevisiae. Increased responses were more evident when these molecules were combined in pairs.

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Atlantic salmon (Salmo salar) post-smolts were fed diets containing either Fosol (FO), a North Sea fish oil, sunflower oil (SO), linseed oil (LO) or Marinol K (MO), a southern hemisphere fish oil rich in 20:5(n-3) for 12 weeks. A macrophage-enriched leucocyte preparation was obtained from head kidney and the fatty acid compositions of the individual membrane phospholipids measured. In general phospholipids from SO- and LO-fed fish had increased 18:2(n-6), 20:2(n-6) and 20:3(n-6) compared to the fish oil treatments while LO-fed fish had lower 20:4(n-6) than any other dietary treatment.

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Study Design: This study is an in vitro investigation of the effects of substance P on intervertebral disc cell metabolism.

Objectives: To determine whether the neuropeptide, substance P, affects cells isolated from the intervertebral disc.

Summary Of The Background Data: Nerve fibers containing substance P are present in the anulus fibrosus and may be released from the nerve terminals as in other tissues.

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Study Design: The present study investigated the occurrence and morphology of mechanoreceptors in human and bovine intervertebral discs and longitudinal ligaments.

Objective: To determine the type and frequency of mechanoreceptors present in intervertebral discs and anterior longitudinal ligaments in two patient groups, those with low back pain and those with scoliosis. Bovine coccygeal discs were examined.

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The annulus fibrosus of the human intervertebral disc is sparsely innervated, some of the fibers containing substance P. We could demonstrate, by autoradiography, binding sites for substance P localized on the endothelium of small blood vessels in the annulus fibrosus of human intervertebral discs removed during anterior fusion for back pain. In binding inhibition studies, binding of 125I-Bolton Hunter-substance P was inhibited by unlabeled substance P and the related tachykinins neurokinin A and neurokinin B with a rank order of potency substance P > NKA > NKB.

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Rainbow trout, Oncorhynchus mykiss, were maintained on isocalorific diets in which either sunflower, menhaden or Fosol oils were used as the dietary source of fatty acids. At intervals over a period of 6 months, head kidney leucocytes were isolated and used for the analysis of their fatty acid composition and eicosanoid-generating capacity. Major changes in fatty acid composition were apparent within 4 weeks on the diets, with fish fed sunflower oil diets showing a 2.

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Proliferation of rainbow trout head kidney leucocytes in response to the mitogen phytohaemagglutinin-P (PHA-P) was modulated in the presence of inhibitors of eicosanoid synthesis and by exogenous eicosanoids. The presence of indomethacin, a cyclooxygenase inhibitor, resulted in a stimulatory effect, whereas the presence of nordihydroguiaretic acid, a lipoxygenase inhibitor, resulted in an inhibitory effect on mitogenicity. The addition of prostaglandins and lipoxins was also found to be inhibitory, whilst the addition of leukotrienes was stimulatory.

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