Controlling periodic long-range signalling to drive a morphogenetic transition

Cells use signal relay to transmit information across tissue scales. However, the production of information carried by signal relay remains poorly characterised. To determine how the coding features of signal relay are generated, we used the classic system for long-range signalling: the periodic cAMP waves that drive Dictyostelium collective migration. Combining imaging and optogenetic perturbation of cell signalling states, we find that migration is triggered by an increase in wave frequency generated at the signalling centre. Wave frequency is regulated by cAMP wave circulation, which organises the long-range signal. To determine the mechanisms modulating wave circulation, we combined mathematical modelling, the general theory of excitable media and mechanical perturbations to test competing models. Models in which cell density and spatial patterning modulate the wave frequency cannot explain the temporal evolution of signalling waves. Instead, our evidence leads to a model where wave circulation increases the ability for cells to relay the signal, causing further increase in the circulation rate. This positive feedback between cell state and signalling pattern regulates the long-range signal coding that drives morphogenesis

Diamicton from the Vale of Pickering and Tabular Hills, north-east Yorkshire: evidence for a Middle Pleistocene (MIS 8) glaciation?

Diamicton deposits (up to 6.90 m thick) in the Vale of Pickering and the Tabular Hills (North York Moors) have been confirmed by cored boreholes. The diamicton is interpreted as glacial till with a matrix consisting predominantly of grey-brown, yellow-brown and dark grey, stiff to very stiff clay and sandy clay with occasional thin beds of laminated sand and clay. Sub-rounded to sub-angular erratic clasts were sourced predominantly from local Upper Jurassic Corallian Group bedrock exposed in the southern part of the North York Moors. Clasts include well-rounded, pebbles of Jurassic sandstone, mudstone and sparse Jurassic coal derived from outcrops on the North York Moors. Fragments of underlying Upper Jurassic mudstone bedrock form the predominant clasts in the lower part of the till. The paucity of exotic clasts and a local derivation suggests a relatively small glacier – perhaps a temperate-plateau ice-field, was established on the Tabular Hills. The glacier subsequently advanced southwards to the Vale of Pickering depositing locally derived subglacial traction till at the base, passing up to lodgement till. Local preservation of the degraded till outcrops in the Vale of Pickering, the overconsolidated nature of the clay till matrix, striated pebbles and the presence of sub-rounded pebbles suggests deposition during a glacial cold stage post-MIS 12 (Anglian) and pre-MIS 2 (Devensian). A tentative Middle Pleistocene MIS8 age is proposed, possibly coeval, but not coincident, with the Basement Till (Bridlington Member) of the Holderness coast and the Wragby Till of central and eastern England

Clearing the slate: RNA turnover to enable cell state switching?

The distribution of mRNA in tissue is determined by the balance between transcription and decay. Understanding the control of RNA decay during development has been somewhat neglected compared with transcriptional control. Here, we explore the potential for mRNA decay to trigger rapid cell state transitions during development, comparing a bistable switch model of cell state conversion with experimental evidence from different developmental systems. We also consider another potential role for large-scale RNA decay that has emerged from studies of stress-induced cell state transitions, in which removal of mRNA unblocks the translation machinery to prioritise the synthesis of proteins that establish the new cell state

Emission Line Galaxies in the STIS Parallel Survey I: Observations and Data Analysis

In the first three years of operation STIS obtained slitless spectra of approximately 2500 fields in parallel to prime HST observations as part of the STIS Parallel Survey (SPS). The archive contains almost 300 fields at high galactic latitude (|b|>30) with spectroscopic exposure times greater than 3000 seconds. This sample contains 220 fields (excluding special regions and requiring a consistent grating angle) observed between 6 June 1997 and 21 September 2000, with a total survey area of about 160 square arcminutes. At this depth, the SPS detects an average of one emission line galaxy per three fields. We present the analysis of these data, and the identification of 131 low to intermediate redshift galaxies detected by optical emission lines. The sample contains 78 objects with emission lines that we infer to be redshifted [OII]3727 emission at 0.43<z<1.7. The comoving number density of these objects is comparable to that of H-alpha emitting galaxies in the NICMOS parallel observations. One quasar and three probable Seyfert galaxies are detected. Many of the emission-line objects show morphologies suggestive of mergers or interactions. The reduced data are available upon request from the authors.Comment: 58 preprint pages, including 26 figures; accepted for publication in ApJ

CWRML: representing crop wild relative conservation and use data in XML

Background Crop wild relatives are wild species that are closely related to crops. They are valuable as potential gene donors for crop improvement and may help to ensure food security for the future. However, they are becoming increasingly threatened in the wild and are inadequately conserved, both in situ and ex situ. Information about the conservation status and utilisation potential of crop wild relatives is diverse and dispersed, and no single agreed standard exists for representing such information; yet, this information is vital to ensure these species are effectively conserved and utilised. The European Community-funded project, European Crop Wild Relative Diversity Assessment and Conservation Forum, determined the minimum information requirements for the conservation and utilisation of crop wild relatives and created the Crop Wild Relative Information System, incorporating an eXtensible Markup Language (XML) schema to aid data sharing and exchange. Results Crop Wild Relative Markup Language (CWRML) was developed to represent the data necessary for crop wild relative conservation and ensure that they can be effectively utilised for crop improvement. The schema partitions data into taxon-, site-, and population-specific elements, to allow for integration with other more general conservation biology schemata which may emerge as accepted standards in the future. These elements are composed of sub-elements, which are structured in order to facilitate the use of the schema in a variety of crop wild relative conservation and use contexts. Pre-existing standards for data representation in conservation biology were reviewed and incorporated into the schema as restrictions on element data contents, where appropriate. Conclusion CWRML provides a flexible data communication format for representing in situ and ex situ conservation status of individual taxa as well as their utilisation potential. The development of the schema highlights a number of instances where additional standards-development may be valuable, particularly with regard to the representation of population-specific data and utilisation potential. As crop wild relatives are intrinsically no different to other wild plant species there is potential for the inclusion of CWRML data elements in the emerging standards for representation of biodiversity data

Women’s expectations and experiences in maternity care: how do women conceptualise the process of continuity?

Objective: to gain an understanding of how women conceptualise continuity of maternity care. Design: a qualitative study involving in-depth semi-structured interviews and thematic analysis. Setting: a range of urban and rural public hospitals in New South Wales, Australia. Participants: 53 women aged 18-44 years (median age 27 years) receiving maternity care in 2011 - 2012. Findings: responses from women suggested five types of continuity: continuity of staff, continuity of relationship, continuity of information, continuity across pregnancies, and continuity across locations. The types of continuity differed by parity and location. Conclusion and implications for practice: continuity of maternity care has a variety of meanings to women. If healthcare providers are to commit to providing woman-centred maternity care it is important to recognise the diversity of women’s experiences, and ensure that systems of care are flexible and appropriate to women’s circumstances and needs

Women’s expectations and experiences in maternity care: how do women conceptualise the process of continuity?

Objective: to gain an understanding of how women conceptualise continuity of maternity care. Design: a qualitative study involving in-depth semi-structured interviews and thematic analysis. Setting: a range of urban and rural public hospitals in New South Wales, Australia. Participants: 53 women aged 18-44 years (median age 27 years) receiving maternity care in 2011 - 2012. Findings: responses from women suggested five types of continuity: continuity of staff, continuity of relationship, continuity of information, continuity across pregnancies, and continuity across locations. The types of continuity differed by parity and location. Conclusion and implications for practice: continuity of maternity care has a variety of meanings to women. If healthcare providers are to commit to providing woman-centred maternity care it is important to recognise the diversity of women’s experiences, and ensure that systems of care are flexible and appropriate to women’s circumstances and needs

3D modelling of geological and anthropogenic deposits at the World Heritage Site of Bryggen in Bergen, Norway

The landscape of many historic cities and the character of their shallow subsurface environments are defined by a legacy of interaction between anthropogenic and geological processes. Anthropogenic deposits and excavations result from processes ranging from archaeological activities to modern urban development. Hence, in heritage cities, any geological investigation should acknowledge the role of past and ongoing human activities, while any archaeological investigation should be conducted with geological processes in mind. In this paper it is shown that 3D geological and anthropogenic models at different scales can provide a holistic system for the management of the subsurface. It provides a framework for the integration of other spatial and processmodels to help assess the preservationpotential for buried heritage. Such an integrated framework model is thus contributing to a decision support system for sustainable urban (re)development and regeneration in cities, while preserving cultural heritage. A collaborative approach is proposed to enhance research and implementation of combined geological and archaeological modelling for sustainable land use planning and heritage preservation, using York and Bryggen as prime examples. This paper presents the status of 3D framework modelling at Bryggen in Norway as an example

The Life Science Exchange: a case study of a sectoral and sub-sectoral knowledge exchange programme

Background: Local and national governments have implemented sector-specific policies to support economic development through innovation, entrepreneurship and knowledge exchange. Supported by the Welsh Government through the European Regional Development Fund, The Life Science Exchange® project was created with the aim to increase interaction between stakeholders, to develop more effective knowledge exchange mechanisms, and to stimulate the formation and maintenance of long-term collaborative relationships within the Welsh life sciences ecosystem. The Life Science Exchange allowed participants to interact with other stakeholder communities (clinical, academic, business, governmental), exchange perspectives and discover new opportunities.Methods: Six sub-sector focus groups comprising over 200 senior stakeholders from academia, industry, the Welsh Government and National Health Service were established. Over 18 months, each focus group provided input to inform healthcare innovation policy and knowledge mapping exercises of their respective sub-sectors. Collaborative projects identified during the focus groups and stakeholder engagement were further developed through sandpit events and bespoke support.Results: Each sub-sector focus group produced a report outlining the significant strengths and opportunities in their respective areas of focus, made recommendations to overcome any ‘system failures’, and identified the stakeholder groups which needed to take action. A second outcome was a stakeholder-driven knowledge mapping exercise for each area of focus. Finally, the sandpit events and bespoke support resulted in participants generating more than £1.66 million in grant funding and inward investment. This article outlines four separate outcomes from the Life Science Exchange programme.Conclusions: The Life Science Exchange process has resulted in a multitude of collaborations, projects, inward investment opportunities and special interest group formations, in addition to securing over ten times its own costs in funding for Wales. The Life Science Exchange model is a simple and straightforward mechanism for a regional or national government to adapt and implement in order to improve innovation, skills, networks and knowledge exchange

Sedimentology and stratigraphy of the Kellaways Sand Member (Lower Callovian), Burythorpe, North Yorkshire, UK

In the Burythorpe area of the Howardian Hills, located on the northern margin of the Market Weighton High, the Callovian succession is represented only by Lower Callovian sediments. These belong to the Kellaways Sand Member (Kellaways Formation), up to 12 m thick, but thinning southwards to 5 m. This contrasts with the more complete Callovian succession (Osgodby Formation) on the Yorkshire coast (Cleveland Basin) which is up to 32.5 m thick. At Burythorpe Quarry the Kellaways Sand Member has yielded palynomorphs and ammonites confirming an Early Callovian (Koenigi Zone) age with depositional hiatuses above and below. The sequence consists of a yellow-white, poorly cemented, fine-to medium grained, unimodal uncemented sand (moulding sand) with sparse grey clay beds and laminae, in marked contrast to the broadly coeval Red Cliff Rock Member (Osgodby Formation) of the Cleveland Basin. The depositional environment is interpreted as a tidally influenced shallow sea on the margin of the Market Weighton High, in a shallow sub-tidal regime, similar to the sub-tidal sand-mud lithofacies in the Heligoland region of the present-day North Sea. Winnowing of the sand in highly mobile substrate resulted in a unimodal grain size, lack of impurities, and sparse shelly- and ichnofaunas. However, during quieter water phases, grey clay laminae were deposited at the base of channels, allowing colonization of the substrate by burrowing ichnofauna and deposition of palynomorphs. Sparse, calcite-cemented tabular beds with a benthic shelly fauna, ammonites, Planolites burrows and mudstone rip-up clasts are interpreted as the deposits of periodic storm events. The marked local variation in thickness of the Kellaways Sand Member in the Howardian Hills is probably due to synsedimentary east–west-trending faulting related to the Flamborough Fault Zone