35 research outputs found
Polysemy in Advertising
The article reviews the conceptual foundations of advertising polysemy – the occurrence of different interpretations for the same advertising message. We discuss how disciplines as diverse as psychology, semiotics and literary theory have dealt with the issue of polysemy, and provide translations and integration among these multiple perspectives. From such review we draw recurrent themes to foster future research in the area and to show how seemingly opposed methodological and theoretical perspectives complement and extend each other. Implications for advertising research and practice are discussed
A scoping study for potential community‐based carbon offsetting schemes in the Falkland Islands
A report to Falklands Conservation. In this report, we consider the potential for a future Falkland Island carbon offsetting scheme. Such a
scheme would provide a mechanism by which businesses, organisations and individuals could invest
in land‐management and restoration schemes that would deliver greenhouse gas reductions or removals,
delivering financial support to farmers and others to adopt sustainable land‐management practices,
undertake restoration and increase the extent of ecologically valuable habitats. Overall, we consider that a Falkland Island peatland carbon offsetting scheme would have the potential to deliver significant climate change mitigation, to support habitat conservation, and to
generate new sources of income for farmers, other landowners and the Islands as a whole. Any
scheme would need to be sustainable and developed in partnership with the camp community and
wider Falkland society to ensure that it is appropriate for the culture, economics and environment of
the Islands
Recommended from our members
The effect of drought on dissolved organic carbon (DOC) release from peatland soil and vegetation sources
Drought conditions are expected to increase in frequency and severity as the climate changes, representing a threat to carbon sequestered in peat soils. Downstream water treatment works are also at risk of regulatory compliance failures and higher treatment costs due to the increase in riverine dissolved organic carbon (DOC) often observed after droughts. More frequent droughts may also shift dominant vegetation in peatlands from Sphagnum moss to more drought tolerant species. This paper examines the impact of drought on the production and treatability of DOC from four vegetation litters (Calluna vulgaris, Juncus effusus, Molinia caerulea and Sphagnum spp.) and a peat soil. We found that mild droughts caused a 39.6 % increase in DOC production from peat and that this DOC was harder to remove by conventional water treatment processes (coagulation/flocculation). Drought had no effect on DOC production from vegetation litters, however large variation was observed between typical peatland species (Sphagnum and Calluna) and drought tolerant grassland species (Juncus and Molinia), with the latter producing more DOC per unit weight. This would therefore suggest the increase in riverine DOC often observed post-drought is due entirely to soil microbial processes and DOC solubility rather than litter-layer effects. Long term shifts in species diversity may, therefore, be the most important impact of drought on litter layer DOC flux, whereas more immediate effects are observed in peat soils. These results provide evidence in support of catchment management which increases the resilience of peat soils to drought, such as ditch-blocking to raise water-tables
Recommended from our members
Sensitivity of peatland litter decomposition to changes in temperature and rainfall
Changes to climate are projected over the next 50 years for many peatland areas. As decomposition of peatforming vegetation is likely to be intrinsically linked to these changes in climate, a clear understanding of climate-peat dynamics is required. There is concern that increased temperature and decreased precipitation could increase the rate of decomposition and put the carbon sink status of many peatlands at risk, yet few studies
have examined the impact of both climatic factors together. To better understand the sensitivity of peatland decomposition to changes in both temperature and precipitation and their interaction, we conducted a shortterm
laboratory experiment in which plant litters and peat soil were incubated, in isolation, in a factorial design.
Treatments simulated baseline and projected climate averages derived from the latest UK climate change projections (UKCP09) for Exmoor, a climatically marginal peatland in SW England. Regular carbon dioxide flux
measurements were made throughout the simulation, as well as total mass loss and total dissolved organic carbon (DOC) leached. The largest effect on carbon loss in this multifactor experiment was from substrate, with
Sphagnum/peat releasing significantly less C in total during the experiment than dwarf shrubs/graminoids.
Climate effects were substrate specific, with the drier rainfall treatment increasing the DOC leaching from
Calluna, but decreasing it from Sphagnum. Partitioning between CO2 and DOC was also affected by climate, but
only for the peat and Sphagnum samples, where the future climate scenarios (warmer and drier) resulted in a
greater proportion of C lost in gaseous form. These results suggest that indirect effects of climate through
changes in species composition in peatlands could ultimately turn out to be more important for litter decomposition
than direct effects of climate change from increased temperatures and decreased rainfall
Recommended from our members
Using spectral indices to estimate water content and GPP in Sphagnum moss and other peatland vegetation
Peatlands provide important ecosystem services including carbon stroage and biodiversity conservation. Remote sensing shows potential for monitoring peatlands, but most off-the-shelf data produces are developed for unsaturated environments and it is unclear how well they can perform in peatland ecosystems. Sphagnum moss is an important peatland genus with specific characteristics which can affect spectral reflectance, and we hypothesized that the prevalence of Sphagnum in a peatland could affect the spectral signature of the area. This study combines results from both laboratory and field experiments to assess the relationship between spectral indices and the moisture content and GPP of peatland (blanket bog) vegetation species. The aim was to consider how well the selected indices perform under a range of conditions, and whether Sphagnum has a significant impact on the relationships tested. We found that both water indices tested (NDWI and fWBI) were sensitive to the water content changes in Sphagnum moss in the laboratory, and there was little difference between them. Most of the vegetation indices tested (the NDVI, EVI, SIPI and CIm) were found to have a strong relationship with GPP both in the laboratory and in the field. The NDVI and EVI are useful for large-scale estimation of GPP, but are sensitive to the proportion of Sphagnum present. The CIm is less affected by different species proportions and might therefore be the best to use in areas where species cover is unknown. The PRI is shown to be best suited to small-scale studies of single species
Recommended from our members
Assessing the reliability of peatland GPP measurements by remote sensing: from plot to landscape scale
Estimates of peatland carbon fluxes based on remote sensing data are a useful addition to monitoring methods in these remote and precious ecosystems, but there are questions as to whether large-scale estimates are reliable given the small-scale heterogeneity of many peatlands. Our objective was to consider the reliability of models based on Earth Observations for estimating ecosystem photosynthesis at different scales using the Forsinard Flows RSPB reserve in Northern Scotland as our study site. Three sites across the reserve were monitored during the growing season of 2017. One site is near-natural blanket bog, and the other two are at different stages of the restoration process after removal of commercial conifer forestry. At each site we measured small (flux chamber) and landscape scale (eddy covariance) CO2 fluxes, small scale spectral data using a handheld spectrometer, and obtained corresponding satellite data from MODIS. The variables influencing GPP at small scale, including microforms and dominant vegetation species, were assessed using exploratory factor analysis. A GPP model using land surface temperature and a measure of greenness from remote sensing data was tested and compared to chamber and eddy covariance CO2 fluxes; this model returned good results at all scales (Pearson’s correlations of 0.57 to 0.71 at small scale, 0.76 to 0.86 at large scale). We found that the effect of microtopography on GPP fluxes at the study sites was spatially and temporally inconsistent, although connected to water content and vegetation species. The GPP fluxes measured using EC were larger than those using chambers at all sites, and the reliability of the TG model at different scales was dependent on the measurement methods used for calibration and validation. This suggests that GPP measurements from remote sensing are robust at all scales, but that the methods used for calibration and validation will impact accuracy
The Use of Preoperative Prophylactic Systemic Antibiotics for the Prevention of Endopthalmitis in Open Globe Injuries:A Meta-Analysis
Topic:This study reports the effect of systemic prophylactic antibiotics (and their route) on the risk of endophthalmitis after open globe injury.
Clinical relevance:Endophthalmitis is a major complication of open globe injury, it can lead to rapid sight loss in the affected eye. The administration of systemic antibiotic prophylaxis is common practice in some health care systems, although there is no consensus on their use.
PubMed, CENTRAL, Web of Science, CINAHL and Embase were searched. This was completed 6th July 2021 and updated 10th Dec 2022. We included randomised and non-randomised prospective studies which reported the rate of post-open globe injury endophthalmitis, when systemic pre-operative antibiotic prophylaxis (via the oral or intravenous route) was given. The Cochrane Risk of Bias tool and ROBINS-I tool were used for assessing the risk of bias.
Where meta-analysis was performed results were reported as odds ratio. PROSPERO registration: CRD42021271271.
Three studies were included. One prospective observational study compared outcomes of patients who had received systemic or no systemic pre-operative antibiotics. The endophthalmitis rates reported were 3.75% and 4.91% in the systemic and no systemic pre-operative antibiotics groups, a non-significant difference (p = 0.68).
Two randomised controlled trials were included (1,555 patients). The rates of endophthalmitis were 17 events in 751 patients (2.26%) and 17 events in 804 patients (2.11%) in the oral antibiotics and intravenous (+/- oral) antibiotics groups, respectively. Meta-analysis demonstrated no significant differences between groups (OR 1.07 [95% confidence interval 0.54 – 2.12]).
The incidences of endophthalmitis after open globe injury were low with and without systemic antibiotic prophylaxis, although high risk cases were excluded in the included studies. When antibiotic prophylaxis is considered, there is moderate evidence that oral antibiotic administration is non-inferior to intravenous
The Risk of Sympathetic Ophthalmia Associated with Open-Globe Injury Management Strategies:A Meta-analysis
Topic: Sympathetic ophthalmia (SO) is a sight-threatening granulomatous panuveitis caused by a sensitizing event. Primary enucleation or primary evisceration, versus primary repair, as a risk management strategy after open-globe injury (OGI) remains controversial.Clinical Relevance: This systematic review was conducted to report the incidence of SO after primary repair compared with that of after primary enucleation or primary evisceration. This enabled the reporting of an estimated number needed to treat.Methods: Five journal databases were searched. This review was registered with International Prospective Register of Systematic Reviews (identifier, CRD42021262616). Searches were carried out on June 29, 2021, and were updated on December 10, 2022. Prospective or retrospective studies that reported outcomes (including SO or lack of SO) in a patient population who underwent either primary repair and primary enucleation or primary evisceration were included. A systematic review and meta-analysis were carried out in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Random effects modelling was used to estimate pooled SO rates and absolute risk reduction (ARR).Results: Eight studies reporting SO as an outcome were included in total. The included studies contained 7500 patients and 7635 OGIs. In total, 7620 OGIs met the criteria for inclusion in this analysis; SO developed in 21 patients with OGI. When all included studies were pooled, the estimated SO rate was 0.12% (95% confidence interval [CI], 0.00%–0.25%) after OGI. Of 779 patients who underwent primary enucleation or primary evisceration, no SO cases were reported, resulting in a pooled SO estimate of 0.05% (95% CI, 0.00%–0.21%). For primary repair, the pooled estimate of SO rate was 0.15% (95% CI, 0.00%–0.33%). The ARR using a random effects model was −0.0010 (in favour of eye removal; 95% CI, −0.0031 [in favor of eye removal] to 0.0011 [in favor of primary repair]). Grading of Recommendations, Assessment, Development, and Evaluations analysis highlighted a low certainty of evidence because the included studies were observational, and a risk of bias resulted from missing data.Discussion: Based on the available data, no evidence exists that primary enucleation or primary evisceration reduce the risk of secondary SO.Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article
Aspects of microbial communities in peatland carbon cycling under changing climate and land use pressures
This is the final version. Available on open access from the Finnish Peatland Society via the DOI in this record. Globally, major efforts are being made to restore peatlands to maximise their resilience to anthropogenic climate change, which puts continuous pressure on peatland ecosystems and modifies the geography of the environmental envelope that underpins peatland functioning. A probable effect of climate change is reduction in the waterlogged conditions that are key to peatland formation and continued accumulation of carbon (C) in peat. C sequestration in peatlands arises from a delicate imbalance between primary production and decomposition, and microbial processes are potentially pivotal in regulating feedbacks between environmental change and the peatland C cycle. Increased soil temperature, caused by climate warming or disturbance of the natural vegetation cover and drainage, may result in reductions of long-term C storage via changes in microbial community composition and metabolic rates. Moreover, changes in water table depth alter the redox state and hence have broad consequences for microbial functions, including effects on fungal and bacterial communities especially methanogens and methanotrophs. This article is a perspective review of the effects of climate change and ecosystem restoration on peatland microbial communities and the implications for C sequestration and climate regulation. It is authored by peatland scientists, microbial ecologists, land managers and non-governmental organisations who were attendees at a series of three workshops held at The University of Manchester (UK) in 2019–2020. Our review suggests that the increase in methane flux sometimes observed when water tables are restored is predicated on the availability of labile carbon from vegetation and the absence of alternative terminal electron acceptors. Peatland microbial communities respond relatively rapidly to shifts in vegetation induced by climate change and subsequent changes in the quantity and quality of below-ground C substrate inputs. Other consequences of climate change that affect peatland microbial communities and C cycling include alterations in snow cover and permafrost thaw. In the face of rapid climate change, restoration of a resilient microbiome is essential to sustaining the climate regulation functions of peatland systems. Technological developments enabling faster characterisation of microbial communities and functions support progress towards this goal, which will require a strongly interdisciplinary approach.Natural Environment Research Council (NERC