The environmental setting of Epipalaeolithic aggregation site Kharaneh IV

The archaeological site of Kharaneh IV in Jordan's Azraq Basin, and its relatively near neighbour Jilat 6 show evidence of sustained occupation of substantial size through the Early to Middle Epipalaeolithic (c. 24,000 - 15,000 cal BP). Here we review the geomorphological evidence for the environmental setting in which Kharaneh IV was established. The on-site stratigraphy is clearly differentiated from surrounding sediments, marked visually as well as by higher magnetic susceptibility values. Dating and analysis of off-site sediments show that a significant wetland existed at the site prior to and during early site occupation (~ 23,000 - 19,000 BP). This may explain why such a substantial site existed at this location. This wetland dating to the Last Glacial Maximum also provides important information on the palaeoenvironments and potential palaeoclimatic scenarios for today's eastern Jordanian desert, from where such evidence is scarce.

Mapping Educational Specialist knowHow (MESH): the building of a knowledge management system for research informed practice

In this invited article the authors present an evaluative report on the development of the MESHGuides project (http://www.meshguides.org/). MESHGuides’ objective is to provide education with an international knowledge management system. MESHGuides were conceived as research summaries for supporting teachers’ in developing evidence-based practice. Their aim is to enhance teachers’ capacity to engage actively with research in their own classrooms. The original thinking for MESH arose from the work of UK-based academics Professor Marilyn Leask and Dr Sarah Younie in response to a desire, which has recently gathered momentum in the UK, for the development of a more research-informed teaching profession and for the establishment of an on-line platform to support evidence-based practice (DfE, 2015; Leask and Younie 2001; OECD 2009). The focus of this article is on how the MESHGuides project was conceived and structured, the technical systems supporting it and the practical reality for academics and teachers of composing and using MESHGuides. The project and the guides are in the early stages of development, and discussion indicates future possibilities for more global engagement with this knowledge management system.

Agricultural innovations at a Late Iron Age oppidum: archaeobotanical evidence for flax, food and fodder from Calleva Atrebatum, UK

The development of oppida in the late first millennium BC across north-western Europe represents a major change in settlement form and social organisation. The construction of extensive earthwork systems, the presence of nucleated settlement areas, long-distance trade links and the development of hierarchical societies have been evidenced. These imply that changes in the style and organisation of agriculture would have been required to support these proto-urban population centres. Hypotheses of the subsistence bases of these settlements, ranging from a reliance on surplus arable production from local rural settlements, to an emphasis on pastoral activities, are here reviewed and grounded against a wider understanding of the expansion of agriculture in the Late Iron Age. These agricultural models have not been previously evaluated. This paper presents archaeobotanical data from six well fills from large-scale excavations at Late Iron Age and Early Roman Silchester, a Late Iron Age territorial oppidum and subsequent Roman civitas capital located in central-southern Britain. This is the first large-scale study of waterlogged plant macrofossils from within a settlement area of an oppidum. Waterlogged plant macrofossils were studied from a series of wells within the settlement. An assessment of taphonomy, considering stratigraphic and contextual information, is reported, followed by an analysis of the diverse assemblages of the plant remains through univariate analysis. Key results evidence animal stabling, flax cultivation, hay meadow management and the use of heathland resources. The staple crops cultivated and consumed at Late Iron Age and Early Roman Silchester are consistent with those cultivated in the wider region, whilst a range of imported fruits and flavourings were also present. The adoption of new oil crops and new grassland management shows that agricultural innovations were associated with foddering for animals rather than providing food for the proto-urban population. The evidence from Silchester is compared with other archaeobotanical datasets from oppida in Europe in order to identify key trends in agricultural change.

Production of bioactive diterpenoids in the Euphorbiaceae depends on evolutionarily conserved gene clusters

The Euphorbiaceae produce a diverse range of diterpenoids, many of which have pharmacological activities. These diterpenoids include ingenol mebutate, which is licensed for the treatment of a precancerous skin condition (actinic keratosis), and phorbol derivatives such as resiniferatoxin and prostratin, which are undergoing investigation for the treatment of severe pain and HIV, respectively. Despite the interest in these diterpenoids, their biosynthesis is poorly understood at present, with the only characterized step being the conversion of geranylgeranyl pyrophosphate into casbene. Here, we report a physical cluster of diterpenoid biosynthetic genes from castor (Ricinus communis), including casbene synthases and cytochrome P450s from the CYP726A subfamily. CYP726A14, CYP726A17, and CYP726A18 were able to catalyze 5-oxidation of casbene, a conserved oxidation step in the biosynthesis of this family of medicinally important diterpenoids. CYP726A16 catalyzed 7,8-epoxidation of 5-keto-casbene and CYP726A15 catalyzed 5-oxidation of neocembrene. Evidence of similar gene clustering was also found in two other Euphorbiaceae, including Euphorbia peplus, the source organism of ingenol mebutate. These results demonstrate conservation of gene clusters at the higher taxonomic level of the plant family and that this phenomenon could prove useful in further elucidating diterpenoid biosynthetic pathways.