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The history of agricultural terraces remains poorly understood due to problems in dating their construction and use. This has hampered broader research on their significance, limiting knowledge of past agricultural practices and the long-term investment choices of rural communities. The authors apply OSL profiling and dating to the sediments associated with agricultural terraces across the Mediterranean region to date their construction and use. Results from five widely dispersed case studies reveal that although many terraces were used in the first millennium AD, the most intensive episodes of terrace-building occurred during the later Middle Ages (c. AD 1100–1600). This innovative approach provides the first large-scale evidence for both the longevity and medieval intensification of Mediterranean terraces.
Kentucky bluegrass, a nonnative species, has invaded rangelands in the United States and is currently present in most rangelands across the Northern Great Plains. Despite its accelerated expansion, the consequences of Kentucky bluegrass on the diversity of native plant species and on ecosystem services remain largely unknown. We synthesized the available data related to Kentucky bluegrass and how it affects native plant diversity and ecosystem services. We found that invasion may bring negative consequences to ecosystem services, such as pollination, habitat for wildlife species, and alteration of nutrient and hydrologic cycles, among others. To maintain the flow of ecosystem goods and services from these rangeland ecosystems, range science must adapt to the challenge of introduced, cool-season grass dominance in mixed-grass prairie. Based on our findings, we identify research needs that address ecosystem changes brought on by Kentucky bluegrass invasion and the corresponding effects these changes have on ecosystem services. We are dealing with novel ecosystems, and until we have better answers, adaptive management strategies that use the best available information need to be developed to adapt to the invasion of this pervasive invasive species.
To examine the use of vitamin D supplements during infancy among the participants in an international infant feeding trial.
Information about vitamin D supplementation was collected through a validated FFQ at the age of 2 weeks and monthly between the ages of 1 month and 6 months.
Infants (n 2159) with a biological family member affected by type 1 diabetes and with increased human leucocyte antigen-conferred susceptibility to type 1 diabetes from twelve European countries, the USA, Canada and Australia.
Daily use of vitamin D supplements was common during the first 6 months of life in Northern and Central Europe (>80 % of the infants), with somewhat lower rates observed in Southern Europe (>60 %). In Canada, vitamin D supplementation was more common among exclusively breast-fed than other infants (e.g. 71 % v. 44 % at 6 months of age). Less than 2 % of infants in the USA and Australia received any vitamin D supplementation. Higher gestational age, older maternal age and longer maternal education were study-wide associated with greater use of vitamin D supplements.
Most of the infants received vitamin D supplements during the first 6 months of life in the European countries, whereas in Canada only half and in the USA and Australia very few were given supplementation.
Given a parametrized model of the Galactic potential, the best-fit parameters can be obtained by maximizing the Kullback-Leibler divergence of the action distribution of a set of stars initially clustered in action space (e.g. stars in tidal streams). This method will allow us to map the Milky Way's gravitational potential by simultaneously fitting multiple tidal streams without requiring stream membership information. With 20 streams of at least 20 stars each, including observational errors consistent with predictions for Gaia, this technique recovers the input potential parameters to a precision of 10-60% and an accuracy of 10%. With all the observed streams in our mock stellar halo (about 40) that fit the error criteria, the precision improves to 10%.
Conservation agricultural systems rely on three principles to enhance ecosystem services: (1) minimizing soil disturbance, (2) maximizing soil surface cover and (3) stimulating biological activity. In this paper, we explore the concept of diversity and its role in maximizing ecosystem services from managed grasslands and integrated agricultural systems (i.e., integrated crop–livestock–forage systems) at the field and farm level. We also examine trade-offs that may be involved in realizing greater ecosystem services. Previous research on livestock production systems, particularly in pastureland, has shown improvements in herbage productivity and reduced weed invasion with increased forage diversity but little response in terms of animal production. Managing forage diversity in pastureland requires new tools to guide the selection and placement of plant mixtures across a farm according to site suitability and the goals of the producer. Integrated agricultural systems embrace the concept of dynamic cropping systems, which incorporates a long-term strategy of annual crop sequencing that optimizes crop and soil use options to attain production, economic and resource conservation goals by using sound ecological management principles. Integrating dynamic cropping systems with livestock production increases the complexity of management, but also creates synergies among system components that may improve resilience and sustainability while fulfilling multiple ecosystem functions. Diversified conservation agricultural systems can sustain crop and livestock production and provide additional ecosystem services such as soil C storage, efficient nutrient cycling and conservation of biodiversity.
Luminescence methods were used to date a palaeoenvironmental coastal exposure on Stronsay, Orkney. The section consists of glacial sediments that are overlain by intercalated peats and windblown sands, implying varying past environmental conditions. Rapid luminescence characterisation was undertaken using screening methods in combination with quantitative dating of selected samples, providing information on depositional processes and chronology. A temporal discontinuity between the glacial sediments and later peats encompasses the period associated with an important Mesolithic site located inland, and implies erosional episodes. The onset of blanket bog formation on Stronsay dates to 3760±330 yrs BP, consistent with observations elsewhere in Orkney and northern Scotland. Periods of enhanced aeolian activity on Stronsay occurred in the late Bronze Age (2700±265 yrs BP) and at the beginning of the Little Ice Age (650±75 yrs BP). Recent periods of sand deposition in the 19th and 20th centuries (AD 1865±20 and 1960±5) correspond to periods of known historic storminess. These results add to an expanding catalogue of data on sand movements throughout the Holocene in Orkney, and set a framework to interpret the evolution of nearby archaeological and natural landscapes from prehistoric to modern times.
The UK Food Standards Agency convened a group of expert scientists to review current research investigating the effect of dietary lipids on vascular function. The workshop highlighted the need for intervention studies to be sufficiently powered for these measures and that they should be corroborated with other, more validated, risk factors for CVD. Work presented at the workshop suggested a beneficial effect of long-chain n-3 PUFA and a detrimental effect of trans fatty acids. The workshop also considered the importance of the choice of study population in dietary intervention studies and that ‘at risk’ subgroups within the general population may be more appropriate than subjects that are unrepresentatively healthy.
It is reported that people with mild learning disability have a higher point prevalence of schizophrenia than the normal population, the reasons for which are unclear.
Thirty-nine subjects with mild learning disability and schizophrenia, 34 control subjects with schizophrenia and 28 control subjects with mild learning disability were seen. Interviews with relatives and carers were also conducted. Assessments were made of clinical variables, psychopathology, neurological ‘soft'signs, IQ, memory and family history. Blood was taken for karyotypic analysis from comorbid subjects.
The comorbid group had more negative symptoms, episodic memory deficits, soft neurological signs, epilepsy and receive more community supports than control subjects with schizophrenia. Comorbid subjects had a tendency to belong to multiply affected families and show high rates of chromosomal variants on routine karyotypic testing.
Future work on the generality of schizophrenia should include people with premorbid learning disability, as a discrete subtype from whom valuable genetic aetiological clues may be obtained.
The dilational intrusion is described of some basalt dykes of Tertiary age into the Easdale Slates at Easdale, Argyllshire. The intrusive form of the dykes results from the walls of irregular fractures, guided by pre-existing planes of weakness, moving apart under magma pressure. The propagation of the fractures is discussed in relation to the external stress field controlling the intrusion of the dykes and the direction of opening of the fractures considered in relation to the magma pressure and the external stress field. The flow lineations developed at the margins of the dykes are discussed in terms of their mode of origin. Although the attitude of these lineations varies with the intrusive form of the dykes, the overall direction of flow of the magma was upwards to the north of northwest.
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