513 research outputs found
Durrington Walls to West Amesbury by way of Stonehenge: a major transformation of the Holocene landscape
No full textA new sequence of Holocene landscape change has been discovered through an investigation of sediment sequences, palaeosols, pollen and molluscan data discovered during the Stonehenge Riverside Project. The early post-glacial vegetational succession in the Avon valley at Durrington Walls was apparently slow and partial, with intermittent woodland modification and the opening-up of this landscape in the later Mesolithic and earlier Neolithic, though a strong element of pine lingered into the third millennium BC. There appears to have been a major hiatus around 2900 cal BC, coincident with the beginnings of demonstrable human activities at Durrington Walls, but slightly after activity started at Stonehenge. This was reflected in episodic increases in channel sedimentation and tree and shrub clearance, leading to a more open downland, with greater indications of anthropogenic activity, and an increasingly wet floodplain with sedges and alder along the river’s edge. Nonetheless, a localized woodland cover remained in the vicinity of DurringtonWalls throughout the third and second millennia BC, perhaps on the higher parts of the downs, while stable grassland, with rendzina soils, predominated on the downland slopes, and alder–hazel carr woodland and sedges continued to fringe the wet floodplain. This evidence is strongly indicative of a stable and managed landscape in Neolithic and Bronze Age times. It is not until c 800–500 cal BC that this landscape was completely cleared, except for the marshy-sedge fringe of the floodplain, and that colluvial sedimentation began in earnest associated with increased arable agriculture, a situation that continued through Roman and historic times
Optically stimulated luminescence dating of the Palaeolithic ‘Super site’ Woodgreen, in the Avon Valley, Hampshire (UK)
No full textThe trait and host plant ecology of aphids and their distribution and abundance in the United Kingdom
No full textAim We characterized the annual populations of 170 aphid species by their log abundance, site occupancy and site continuity (i.e. the persistence of species in time) and used this information to make predictions about groups of species that displayed characteristic patterns. By doing so, we aimed to identify commonalities in functional traits (host-alternation; mode of reproduction; life-cycle plasticity; median body size) and host plant geographic range sizes that may indicate why some species are common and others not. Location The population dynamics of winged aphids at 27 locations in the United Kingdom were studied. Methods The annual numbers of aphids were studied using a dataset comprising over 11 million individuals across 509 site-years. Traits and host plants were analysed using linear mixed effects models and nonlinear regression models. Results Linear mixed effects models showed that the fixed effects of host alternation and winter host plant area of occupancy were important in predicting log abundance, site occupancy and site continuity. Life-cycle plasticity was also a significant effect, although not for log abundance. Relationships between site continuity, site occupancy and log abundance were strongly nonlinear. Site continuity always lagged site occupancy, indicating that species were less likely to retain previously occupied sites when abundances were low. Main conclusions Aphid traits are a better paradigm than taxonomic relatedness in explaining macroecological patterns. Host alternation induces an annual flux of migrants that engenders higher annual log abundances, consistent with the theory that species with high local densities tend to confer a much wider distribution than those with low densities. The abundance of aphids is monotonically related to the geographic range size of their winter host, suggestive of a strong bottom-up effect (i.e. resource controlled). The areas of occupancy (AOO) of winter host plants constrain aphids to low abundances because a greater proportion of hosts are trees and shrubs which tend to have smaller AOO than herbs and grasses, the common summer host types
Multivariate spatial statistical analysis of multiple experiments and longitudinal data in perennial crops.
No full textThe advantages of using spatial analysis in annual crop experiments are well documented. There is much less evidence for perennial crops. For the sequence of measurements in perennial crops, apparently, there are no published articles in spatial analysis to date. This paper aimed at the comparison of several models, including auto-regressive, ante-dependence and character process models, in modelling sequences of measurements in perennial plants. The use of smoothed models, including splines, to give parsimonious response models, was also investigated. To access model performance, residual maximum likelihood ratio tests (LRT) and Akaike Criterion Information (AIC), were used. We analysed a total of 22,320 observations from 2 trials of tea plant concerning 5 yield annual measures through different spatial and non-spatial models. The classes of methods used were: (1) univariate spatial models for individual annual measures on each trial; (2) longitudinal non-spatial models for the several measures on each trial; (3) longitudinal and spatial models simultaneously for repeated measures in each trial. The main results obtained were: for individual analysis, the best model out of 19 was the row-column analysis + a first-order spatial auto-regressive (AR1 x AR1) correlated error + independent term error, which provided efficiency (ratio between adjusted heritabilities associated with spatial and non spatial models) between 1.09 and 1.76 over block analysis, i.e., between 9% and 76% of improvement; the same model, however, with a second-order spatial auto-regressive (AR2 x AR2) correlated error, was not superior to (AR1 x AR1); the traits (sequence measurements in consecutive years) gave approximately the same behaviour in terms of results across models; the repeatability and the full unconstrained models were not adequate for the sequences of measures, which exhibited considerable variance heterogeneity between traits and high correlation between measures, revealing a need for new modelling. In general, the best approaches involved the modelling of treatment effects by ante-dependence (SAD) or auto-regressive models with heterogeneous variance (ARH). When the spatial effects are important, a combination of first order spatial auto-regressive approach for modelling errors and a multivariate (including simpler options such as SAD and ARH) approach for modelling treatments effects should be used
A comparison of analysis methods for late-stage variety evaluation trials
No full textSummaryThe statistical analysis of late‐stage variety evaluation trials using a mixed model is described, with one‐ or two‐stage approaches to the analysis. Two sets of trials, from Australia and the UK, were used to provide realistic scenarios for a simulation study to evaluate the different methods of analysis. This study showed that a one‐stage approach gave the most accurate predictions of variety performance overall or within each environment, across a range of models, as measured by mean squared error of prediction or realized genetic gain. A weighted two‐stage approach performed adequately for variety predictions both overall and within environments, but a two‐stage unweighted approach performed poorly in both cases. A generalized heritability measure was developed to compare methods.Sue J. Welham, Beverley J. Gogel, Alison B. Smith, Robin Thompson and Brian R. Culli
Dietary phosphorus intake and its association with metabolic syndrome and its components: a cross-sectional analysis of the UK national diet and nutrition survey (NDNS)
No full textPurpose: Phosphorus plays a critical role in carbohydrate and energy metabolism, yet its relationship with metabolic health outcomes remains underexplored. This study aimed to investigate the association between dietary phosphorus intake and the prevalence of metabolic syndrome (MetS), as well as individual MetS components, using data from the UK National Diet and Nutrition Survey. Methods: Data from adults aged 19 years and older were analyzed. Dietary phosphorus intake was assessed using four-day food diaries. MetS was defined based on established clinical criteria. Logistic regression models evaluated the association between phosphorus intake quintiles and MetS occurrence, adjusting for demographic, anthropometric, dietary, and lifestyle factors. Associations between phosphorus intake and individual MetS components were examined based on both total phosphorus intake and phosphorus density. Results: Individuals in the highest phosphorus intake quintile (> 1509 mg/day) exhibited a 56% lower risk of MetS compared to those in the lowest quintile (OR = 0.44, p = 0.0004). Higher phosphorus intake was associated with a decrease of 10.4 mg/dl in triglyceride levels from quintile 1 to quintile 5 (mean ± SD: 118.6 ± 87.5 vs. 108.2 ± 61.7, p = 0.002), as well as a 2.1 mmHg reduction in diastolic blood pressure (mean ± SD: 74.6 ± 11.1 vs. 72.5 ± 10.7, p = 0.001). Additionally, modest variations in HDL cholesterol and waist circumference were observed. Conclusion: Higher dietary phosphorus intake was associated with a lower risk of MetS and beneficial differences in certain MetS components, supporting a potential protective role of phosphorus in metabolic health
The age of Stonehenge
No full textStonehenge is the icon of British prehistory, and continues to inspire ingenious investigations and interpretations. A current campaign of research, being waged by probably the strongest archaeological team ever assembled, is focused not just on the monument, but on its landscape, its hinterland and the monuments within it. The campaign is still in progress, but the story so far is well worth reporting. Revisiting records of 100 years ago the authors demonstrate that the ambiguous dating of the trilithons, the grand centrepiece of Stonehenge, was based on samples taken from the wrong context, and can now be settled at 2600-2400 cal BC This means that the trilithons are contemporary with Durrington Walls, near neighbour and Britain largest henge monument. These two monuments, different but complementary, now predate the earliest Beaker burials in Britain - including the famous Amesbury Archer and Boscombe Bowmen, but may already have been receiving Beaker pottery. All this contributes to a new vision of massive monumental development in a period of high European intellectual mobility
Phoenix rising: new models for the research monograph?
No full textThere is significant evidence that traditional university presses are continuing to face financial crises. Outlets for research monographs are drying up, print runs are being reduced and monograph costs are increasing. The combination of the digital networked environment and open-archive initiatives may, however, provide the opportunity, through institutional repositories, to rethink the role and nature of the distribution of research monographs in a university setting. The adoption of new models, untrammellled by the structures of the past, while still retaining editorial and refereeing standards, could revolutionize the access and distribution patterns of research knowledge within university frameworks. Ultimate success will depend, however on programmes of scholarly advocacy in scholarly communication with the academic author as both creator and as consumer
Provisional Survey of Aitutaki, Cook islands Sites and Monuments May-June 2017
No full textThe archaeological survey work detailed in this report was undertaken by Colin Richards and Jane Downes (University of the Highlands and Islands, UK), Kate Welham (Bournemouth University, UK), Francisco Torres Hochstetter (MAPSE, Rapa Nui (Easter Island), Chile) and Lawrence Shaw (New Forest National Park Authority, UK), working with Ngaakitai Pureariki (Punarei Aitutaki), with the permission of the Aitutaki Council, and Cook Islands Research Permit (Ref. 15-16a), working between 23rd May and 2nd June 2017. The archaeological work comprised site survey and location using GPS, geophysical survey, and surface collection of artefacts. A database of the sites has been produced as a Cultural Heritage Record, and lodged with the Aitutaki Islands Council. All artefacts have been left on the island with the Aitutaki Islands Council
Rapa Nui (Easter Island)’s Stone Worlds
No full textThis article explores the spatial, architectural and conceptual relationships between landscape places, stone quarrying, and stone moving and building during Rapa Nui’s statue-building period. These are central themes of the ‘Rapa Nui Landscapes of Construction Project’ and are discussed using aspects of the findings of our recent fieldwork. The different scales of expression, from the detail of the domestic sphere to the monumental working of quarries, are considered. It is suggested that the impressiveness of Rapa Nui’s stone architecture is its conceptual coherence at the small scale as much as at the large scale. </div
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