Empirical consequences of symmetries

`Global' symmetries, such as the boost invariance of classical mechanics and special relativity, can give rise to direct empirical counterparts such as the Galileo-ship phenomenon. However, a widely accepted line of thought holds that `local' symmetries, such as the diffeomorphism invariance of general relativity and the gauge invariance of classical electromagnetism, have no such direct empirical counterparts. We argue against this line of thought. We develop a framework for analysing the relationship between Galileo-ship empirical phenomena and physical theories that model such phenomena that renders the relationship between theoretical and empirical symmetries transparent, and from which it follows that both global and local symmetries can give rise to Galileo-ship phenomena. In particular, we use this framework to exhibit analogs of Galileo's ship for both the diffeomorphism invariance of general relativity and the gauge invariance of electromagnetism.Comment: 31 pages including reference

Re-assemblage of plant communities: a survey of floodplain meadow restoration projects in the UK

Re-assemblage of plant communities on the restoration sites is a slow process, largely dependent on historic use of the sites prior to restoration, the amount of applied propagules, site management during early restoration stages, and speed of ontogenesis of the target species. Use of the MAVIS calculator of similarity scores between existing vegetation and standard plant communities as described in British NVC, showed the potential of measuring restoration progress. Most of the restoration sites and most of forming plant communities scored 50-60%, which is slightly indicative towards a good progress in community re-assemblag

Evidence for sensitivity of dune wetlands to groundwater nutrients

Dune slacks are seasonal wetlands, high in biodiversity, which experience considerable within-year and between-year variations in water-table. They are subject to many pressures including climate change, land use change and eutrophication. Despite their biological importance and the threats facing them, the hydrological and nutrient parameters that influence their soil properties and biodiversity are poorly understood and there have been no empirical studies to date testing for biological effects in dune systems resulting from groundwater nutrients at low concentrations. In this study we examined the impact of groundwater nutrients on water chemistry, soil chemistry and vegetation composition of dune slacks at three distance classes (0-150 m, 150–300 m, 300–450 m) away from known (off-site) nutrient sources at Aberffraw dunes in North Wales, whilst controlling for differences in water-table regime. Groundwater nitrate and dissolved inorganic nitrogen (DIN) and soil nitrate and nitrite all had significantly higher concentrations closest to the nutrient source. Multivariate analysis showed that although plant species composition within this site was primarily controlled by water table depth and water table fluctuation, nitrogen from groundwater also influenced species composition, independently of water table and soil development. A model containing all hydrological parameters explained 17% of the total species variance; an additional 7% was explained following the addition of NO3 to this model. Areas exposed to elevated, but still relatively low, groundwater nutrient concentrations (mean 0.204 mg/L +/- 0.091 of DIN) had greater abundance of nitrophilous species and fewer basipholous species. This shows clear biological impact below previously suggested DIN thresholds of 0.20 – 0.40 (mg/L)

Protecting small populations of rare species. Case study on dactylorhiza viridis (orchidaceae) in Fancott Woods and Meadows SSSI, Bedfordshire, UK

Dactylorhiza viridis is a small orchid species, sensitive to competition with dense and tall herbaceous vegetation. Its populations in Europe and in the UK have been declining over the last century. Small, isolated populations have remained in Protected Areas. The population of the species in Fancott Woods and Meadows Site of Special Scientific Interest (SSSI) was studied in 2011–2019. The number of orchid plants varies substantially from year to year, but the areas occupied by the population remain the same. Fruit production is high. The population is under threat from herbivores and from competition with tall vegetation on the meadow. Expansion of the vigorous herb Filipendula ulmaria was recorded on the meadow in 2009 that negatively affected the rare plant community. Additional management of an early hay cut was implemented on the meadow as a trial. A botanical survey of managed and control plots showed a reduction in the vigorous herbs, an increase in species number in the cut plots and a resulting more open sward. The orchid population also benefits from a more open sward. The management of the site is the key to the survival of this small orchid population

Meadows and more: a botanical journal of five days on the Uists, Benbecula and Eriskay

In the first week of July 2018, the Floodplain Meadows Partnership (FMP) held its annual steering group meeting with field excursions on the Outer Hebrides. The aim of the field part of our meeting was to familiarise ourselves with wet meadows (including those on machair) of the Uists and Benbecula, and compare their composition and ecology with related habitats further south in the UK. However, a chance for us to explore the other habitats of these islands was too good an opportunity to miss. Hence five of us arrived on the islands a few days before the main group and roamed more extensively, looking at a wide range of habitats in addition to meadows. The lead author’s role in this botanical journal was to note incidental observations made in addition to the formal study of the meadows. Hilary Wallace directed the quadrat recording in wet meadows, and the overall programme of work was coordinated by David Gowing and Emma Rothero of the Open University. Even during the FMP field excursions, we could not ignore other habitats entirely and Stewart Clarke (National Trust Freshwaters and Estuaries Specialist) paid special attention to the aquatic flora

Restoration of a floodplain meadow in Wiltshire, UK through application of green hay and conversion from pasture to meadow management

In July 2010 green hay from a species-rich donor field was used to diversify a species-poor floodplain meadow (the receiver field), which had previously been managed as a pasture. The receiver site was prepared through harrowing. Green hay was then collected from the donor site and spread on the receiver site using a bale shredder and spreader. It was then managed as a hay meadow, with an annual hay cut in July or August, followed by aftermath grazing. The vegetation in the receiver field was monitored from 2010-2017, as was an adjacent species-rich meadow, which was used as a target reference site. Over this period, the receiver field moved towards a species-rich sward, similar to the target Alopecurus pratensis-Sansguisorba officinalis floodplain community. In 2011, 12 months after the green hay application and change of management, species richness had increased significantly, as had the goodness-of-fit to the target floodplain-meadow community. The transformation from species-poor eutrophicated grassland to a more herb-rich floodplain meadow continued over the following six years, with further increases in the frequency and cover of target species

Meadows and more: a botanical journal of five days on the Uists, Benbecula and Eriskay

In the first week of July 2018, the Floodplain Meadows Partnership (FMP) held its annual steering group meeting with field excursions on the Outer Hebrides. The aim of the field part of our meeting was to familiarise ourselves with wet meadows (including those on machair) of the Uists and Benbecula, and compare their composition and ecology with related habitats further south in the UK. However, a chance for us to explore the other habitats of these islands was too good an opportunity to miss. Hence five of us arrived on the islands a few days before the main group and roamed more extensively, looking at a wide range of habitats in addition to meadows. The lead author’s role in this botanical journal was to note incidental observations made in addition to the formal study of the meadows. Hilary Wallace directed the quadrat recording in wet meadows, and the overall programme of work was coordinated by David Gowing and Emma Rothero of the Open University. Even during the FMP field excursions, we could not ignore other habitats entirely and Stewart Clarke (National Trust Freshwaters and Estuaries Specialist) paid special attention to the aquatic flora

Genetic influence on scar height and pliability after burn injury in individuals of European ancestry: A prospective cohort study

After similar extent of injury there is considerable variability in scarring between individuals, in part due to genetic factors. This study aimed to identify genetic variants associated with scar height and pliability after burn injury. An exome-wide array association study and gene pathway analysis were performed on a prospective cohort of 665 patients treated for burn injury. Outcomes were scar height (SH) and scar pliability (SP) sub-scores of the modified Vancouver Scar Scale (mVSS). DNA was genotyped using the Infinium® HumanCoreExome-24 BeadChip. Associations between genetic variants (single nucleotide polymorphisms) and SH and SP were estimated using an additive genetic model adjusting for age, sex, number of surgical procedures and % total body surface area of burn in subjects of European ancestry. No individual genetic variants achieved the cut-off threshold of significance. Gene regions were analysed for spatially correlated single nucleotide polymorphisms and significant regions identified using comb-p software. This gene list was subject to gene pathway analysis to find which biological process terms were over-represented. Using this approach biological processes related to the nervous system and cell adhesion were the predominant gene pathways associated with both SH and SP. This study suggests genes associated with innervation may be important in scar fibrosis. Further studies using similar and larger datasets will be essential to validate these findings

Floodplain meadow partnership: A working model of effective communication between practitioners, academics and policymakers

1. The article describes a model system for facilitating the transfer of knowledge between researchers and practitioners. 2. The system described has a focus on a single habitat, floodplain meadows, and a case is made for replicating the model for other habitats. 3. Even a single habitat has a wide variety of stakeholders, but a focused partnership with representation across the stakeholder community can prove a useful vehicle for disseminating knowledge and best practice. 4. The structure of the partnership is set out from a steering group to local representatives, and the division of tasks between specialists is explained. 5. The partnership is UK-based and UK-focused, yet has an international dimension. 6. The longevity of the partnership and the intensity of interaction with stakeholders are concluded to be important and suggested as a model for others to follow

Isolation of SARS-CoV-2 in viral cell culture in immunocompromised patients with persistently positive RT-PCR results

Immunocompromised adults can have prolonged acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positive RT-PCR results, long after the initial diagnosis of coronavirus disease 2019 (COVID-19). This study aimed to determine if SARS-CoV-2 virus can be recovered in viral cell culture from immunocompromised adults with persistently positive SARS-CoV-2 RT-PCR tests. We obtained 20 remnant SARS-CoV-2 PCR positive nasopharyngeal swabs from 20 immunocompromised adults with a positive RT-PCR test ≥14 days after the initial positive test. The patients\u27