55 research outputs found
Are agriâenvironment schemes successful in delivering conservation grazing management on saltmarsh?
1.Grasslands occur around the globe and, in temperate regions, their natural management by fire, drought and wild herbivores has largely been replaced by grazing with domestic livestock. Successful management for agriculture is not always suitable for conservation and can have a detrimental effect on biodiversity. Conservation grazing of saltmarshes, delivered through agriâenvironment schemes, may provide a solution to counteract biodiversity loss by providing farmers with financial incentives to graze these internationally important coastal wetlands more sensitively. 2.To assess whether conservation grazing is being achieved, and whether agriâenvironment schemes are effective in delivering this management, we conducted a national survey on English saltmarshes, scoring the management on each site as optimal, suboptimal or detrimental in terms of suitability for achieving conservation aims for five aspects of grazing: presence, stock type, intensity, timing and habitat impact. 3.Although most saltmarshes suitable for grazing in England were grazed, conservation grazing was not being achieved. Sites under agriâenvironment management for longer did score higher and approached optimal levels in terms of grazing intensity in one region, but sites with agriâenvironment agreements were no more likely to be grazed at optimal conservation levels than sites without them overall, indicating that agriâenvironment schemes, in their current form, are an ineffective delivery mechanism for conservation grazing on saltmarsh. 4.The low specificity of agriâenvironment prescription wording may contribute to this failure, with prescriptions either being vague or specifying suboptimal or detrimental management objectives, particularly for grazing intensity, timing and stock type. These objectives are often set too high or too low, during unsuitable periods, or using stock types inappropriate for achieving conservation aims. 5.Synthesis and applications. Our national survey indicates that agriâenvironment schemes are not currently delivering conservation grazing on English saltmarshes. Agriâenvironment schemes are the only mechanism through which such grazing can be implemented on a national scale, so improving their effectiveness is a priority. Policymakers, researchers and managers need to work together to ensure better translation of conservation guidelines into schemes, increasing the specificity of management prescriptions and improving understanding of the need for management measures. A more detailed and reliable system of auditing to ensure that management activities are taking place would be beneficial, or alternatively moving to a resultsâbased scheme where payments are made on desirable outcomes rather than on evidence of management
Factors influencing the initial establishment of salt marsh vegetation on engineered sea wall terraces in south east England
Sea walls provide vital flood protection for lowland coastal property. We investigated the integrity of a cost-effective method of repairing sea defences, which has potential to create habitat for coastal and salt marsh flora. Experimental stone-gabion and clay-filled terraces were installed as a soft engineered approach to repair damaged sea walls in estuarine embayments in south east England. Changes in the surface heights of sediment and vascular plant colonisation were monitored over a 22 month period. Seven of the 12 terraces were colonised, by 12 species of plant, reaching a maximum of 85% cover. The main drivers of plant colonisation were sediment stability, elevation, exposure and sediment shear strength. Terraces with least change in the surface height of sediments were favourable for plant colonisation. Ordination (Canonical Correspondence Analysis) showed 72% variation in plant distribution explained by elevation (37%), exposure (30%), terrace length and sediment shear strength (5%). Elevation was the most influential variable; recruitment increased as terrace height approached the height of existing marsh (r2 = 0.43). This cost-effective approach has the potential to provide protection to sea walls and create additional habitat for wildlife. Key considerations for the improvement of terrace design and construction are discussed
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Nest trampling and ground nesting birds: quantifying temporal and spatial overlap between cattle activity and breeding redshank
Conservation grazing for breeding birds needs to balance the positive effects on vegetation structure and negative effects of nest trampling. In the UK, populations of Common redshank Tringa totanus breeding on saltmarshes declined by >50% between 1985 and 2011. These declines have been linked to changes in grazing management. The highest breeding densities of redshank on saltmarshes are found in lightly grazed areas. Conservation initiatives have encouraged low-intensity grazing at <1 cattle/ha, but even these levels of grazing can result in high levels of nest trampling. If livestock distribution is not spatially or temporally homogenous but concentrated where and when redshank breed, rates of nest trampling may be much higher than expected based on livestock density alone. By GPS tracking cattle on saltmarshes and monitoring trampling of dummy nests, this study quantified (i) the spatial and temporal distribution of cattle in relation to the distribution of redshank nesting habitats and (ii) trampling rates of dummy nests. The distribution of livestock was highly variable depending on both time in the season and the saltmarsh under study, with cattle using between 3% and 42% of the saltmarsh extent and spending most their time on higher elevation habitat within 500 m of the sea wall, but moving further onto the saltmarsh as the season progressed. Breeding redshank also nest on these higher elevation zones, and this breeding coincides with the early period of grazing. Probability of nest trampling was correlated to livestock density and was up to six times higher in the areas where redshank breed. This overlap in both space and time of the habitat use of cattle and redshank means that the trampling probability of a nest can be much higher than would be expected based on standard measures of cattle density. Synthesis and applications: Because saltmarsh grazing is required to maintain a favorable vegetation structure for redshank breeding, grazing management should aim to keep livestock away from redshank nesting habitat between mid-April and mid-July when nests are active, through delaying the onset of grazing or introducing a rotational grazing system
Chemotherapy in advanced ovarian cancer: four systematic meta-analyses of individual patient data from 37 randomized trials. Advanced Ovarian Cancer Trialists' Group.
The purpose of this systematic study was to provide an up to date and reliable quantitative summary of the relative benefits of various types of chemotherapy (non-platinum vs platinum, single-agent vs combination and carboplatin vs cisplatin) in the treatment of advanced ovarian cancer. Also, to investigate whether well-defined patient subgroups benefit more or less from cisplatin- or carboplatin-based therapy. Meta-analyses were based on updated individual patient data from all available randomized controlled trials (published and unpublished), including 37 trials, 5667 patients and 4664 deaths. The results suggest that platinum-based chemotherapy is better than non-platinum therapy, show a trend in favour of platinum combinations over single-agent platinum, and suggest that cisplatin and carboplatin are equally effective. There is no good evidence that cisplatin is more or less effective than carboplatin in any particular subgroup of patients
Potential vectors of equine arboviruses in the UK
There is growing concern about the increasing risk of disease outbreaks caused by arthropod-borne viruses (arboviruses) in both humans and animals. There are several mosquito-borne viral diseases that cause varying levels of morbidity and mortality in horses and that can have substantial welfare and economic ramifications. While none has been recorded in the UK, vector species for some of these viruses are present, suggesting that UK equines may be at risk. We undertook, therefore, the first study of mosquito species on equine premises in the UK. Mosquito Magnet traps and red-box traps were used to sample adults, and larvae were collected from water sources such as tyres, buckets, ditches and pools. Several species which are known to be capable of transmitting important equine infectious arboviruses were trapped. The most abundant, with a maximum catch of 173 in 72 hours was Ochlerotatus detritus, a competent vector of some flaviviruses; the highest densities were found near saltmarsh habitats. The most widespread species, recorded at >75% of sites, was Culiseta annulata. This study demonstrates that potential mosquito vectors of arboviruses, including those known to be capable of infecting horses, are present and may be abundant on equine premises in the UK
Evaluation of salt marsh restoration by means of self-regulating tidal gate â Avon estuary, South Devon, UK
publisher: Elsevier articletitle: Evaluation of salt marsh restoration by means of self-regulating tidal gate â Avon estuary, South Devon, UK journaltitle: Ecological Engineering articlelink: http://dx.doi.org/10.1016/j.ecoleng.2017.05.038 content_type: article copyright: Crown Copyright © 2017 Published by Elsevier B.V. All rights reserved
EFFECTS OF METFORMIN ON GLUCOSE UPTAKE BY ISOLATED DIAPHRAGM FROM NORMAL AND DIABETIC RATS
The effects of the antidiabetic drug metformin (Nl, Nl-dimethylbiguanide) on glucose uptake by isolated rat diaphragm muscle have been studied. A therapeutic concentration of metformin (10 Όg/ml) had no effect on glucose uptake by diaphragm muscle from normal rats incubated in the absence or presence of insulin (100 and 1000 ΌU/ml), but increased uptake by diaphragm muscle from alloxan-diabetic rats incubated in the presence of insulin (P < 0.05). Diaphragm muscle from normal rats incubated in a medium containing sodium butyrate (0.25 mg/ml) showed a reduction in glucose uptake similar to that seen in muscle from diabetic animals. Metformin (10 Όg/ml) also increased glucose uptake by this preparation in the presence of insulin (P < 0.01). A higher concentration of metformin (100 Όg/ml) caused a depression of glucose uptake by diaphragms from normal rats, and the necessity for studying therapeutic concentrations of the biguanide drugs is stressed. The relation of these findings to the antidiabetic effect of the drug in man is discussed. The mechanisms involved are discussed in terms of changes in glycogen metabolism. © 1972
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