Cryo-negative staining reveals conformational flexibility within yeast RNA polymerase I.

The structure of the yeast DNA-dependent RNA polymerase I (RNA Pol I), prepared by cryo-negative staining, was studied by electron microscopy. A structural model of the enzyme at a resolution of 1.8 nm was determined from the analysis of isolated molecules and showed an excellent fit with the atomic structure of the RNA Pol II Delta4/7. The high signal-to-noise ratio (SNR) of the stained molecular images revealed a conformational flexibility within the image data set that could be recovered in three-dimensions after implementation of a novel strategy to sort the "open" and "closed" conformations in our heterogeneous data set. This conformational change mapped in the "wall/flap" domain of the second largest subunit (beta-like) and allows a better accessibility of the DNA-binding groove. This displacement of the wall/flap domain could play an important role in the transition between initiation and elongation state of the enzyme. Moreover, a protrusion was apparent in the cryo-negatively stained model, which was absent in the atomic structure and was not detected in previous 3D models of RNA Pol I. This structure could, however, be detected in unstained views of the enzyme obtained from frozen hydrated 2D crystals, indicating that this novel feature is not induced by the staining process. Unexpectedly, negatively charged molybdenum compounds were found to accumulate within the DNA-binding groove, which is best explained by the highly positive electrostatic potential of this region of the molecule, thus, suggesting that the stain distribution reflects the overall surface charge of the molecule.

E2F activation of S phase promoters via association with HCF-1 and the MLL family of histone H3K4 methyltransferases.

E2F transcriptional regulators control human-cell proliferation by repressing and activating the transcription of genes required for cell-cycle progression, particularly the S phase. E2F proteins repress transcription in association with retinoblastoma pocket proteins, but less is known about how they activate transcription. Here, we show that the human G1 phase regulator HCF-1 associates with both activator (E2F1 and E2F3a) and repressor (E2F4) E2F proteins, properties that are conserved in insect cells. Human HCF-1-E2F interactions are versatile: their associations and binding to E2F-responsive promoters are cell-cycle selective, and HCF-1 displays coactivator properties when bound to the E2F1 activator and corepressor properties when bound to the E2F4 repressor. During the G1-to-S phase transition, HCF-1 recruits the mixed-lineage leukemia (MLL) and Set-1 histone H3 lysine 4 methyltransferases to E2F-responsive promoters and induces histone methylation and transcriptional activation. These results suggest that HCF-1 induces cell-cycle-specific transcriptional activation by E2F proteins to promote cell proliferation.

Missed Opportunities: Evolution of Patients Leaving without Being Seen or against Medical Advice during a Six-Year Period in a Swiss Tertiary Hospital Emergency Department.

Aim. The study aimed at describing the evolution over a 6-year period of patients leaving the emergency department (ED) before being seen ("left without being seen" or LWBS) or against medical advice ("left against medical advice" or LAMA) and at describing their characteristics. Methods. A retrospective database analysis of all adult patients who are admitted to the ED, between 2005 and 2010, and who left before being evaluated or against medical advice, in a tertiary university hospital. Results. During the study period, among the 307,716 patients who were registered in the ED, 1,157 LWBS (0.4%) and 1,853 LAMA (0.9%) patients were identified. These proportions remained stable over the period. The patients had an average age of 38.5 ± 15.9 years for LWBS and 41.9 ± 17.4 years for LAMA. The median time spent in the ED before leaving was 102.4 minutes for the LWBS patients and 226 minutes for LAMA patients. The most frequent reason for LAMA was related to the excessive length of stay. Conclusion. The rates of LWBS and LAMA patients were low and remained stable. The patients shared similar characteristics and reasons for leaving were largely related to the length of stay or waiting time.

Combining probabilistic land-use change and tree population dynamics modelling to simulate responses in mountain forests

Altitudinal tree lines are mainly constrained by temperature, but can also be influenced by factors such as human activity, particularly in the European Alps, where centuries of agricultural use have affected the tree-line. Over the last decades this trend has been reversed due to changing agricultural practices and land-abandonment. We aimed to combine a statistical land-abandonment model with a forest dynamics model, to take into account the combined effects of climate and human land-use on the Alpine tree-line in Switzerland. Land-abandonment probability was expressed by a logistic regression function of degree-day sum, distance from forest edge, soil stoniness, slope, proportion of employees in the secondary and tertiary sectors, proportion of commuters and proportion of full-time farms. This was implemented in the TreeMig spatio-temporal forest model. Distance from forest edge and degree-day sum vary through feed-back from the dynamics part of TreeMig and climate change scenarios, while the other variables remain constant for each grid cell over time. The new model, TreeMig-LAb, was tested on theoretical landscapes, where the variables in the land-abandonment model were varied one by one. This confirmed the strong influence of distance from forest and slope on the abandonment probability. Degree-day sum has a more complex role, with opposite influences on land-abandonment and forest growth. TreeMig-LAb was also applied to a case study area in the Upper Engadine (Swiss Alps), along with a model where abandonment probability was a constant. Two scenarios were used: natural succession only (100% probability) and a probability of abandonment based on past transition proportions in that area (2.1% per decade). The former showed new forest growing in all but the highest-altitude locations. The latter was more realistic as to numbers of newly forested cells, but their location was random and the resulting landscape heterogeneous. Using the logistic regression model gave results consistent with observed patterns of land-abandonment: existing forests expanded and gaps closed, leading to an increasingly homogeneous landscape.

The Establishment of Hospital Groups as a transition to Independent Hospital Trusts

This is the Report on the Establishment of Hospital Groups as a Transition to Independent Hospital Trusts, as approved by Government on 14 May 2013. Click here to download The Establishment of Hospital Groups as a transition to Independent Hospital Trusts PDF 5.59MB Click here to download Securing the Future of Smaller Hospitals: A Framework for Development PDF 401KB Click here to download Frequently Asked Questions PDF 1.19MB  

Differential expression of notch signaling-related transcripts accompanies Pro-thymocyte proliferation and phenotype transition induced by epidermal growth factor plus insulin in fetal thymus organ cultures

Thymus regression upon stressing stimuli, such as infectious diseases, is followed by organ reconstitution, paralleling its development in ontogeny. A narrow window of thymus development was here studied, encompassing the pro-T lymphoid precursor expansion during specification stages, by the use of epidermal growth factor plus insulin (INS) in murine fetal thymus organ cultures. Aiming to disclose signaling pathways related to these stages, cultured thymus lobes had their RNA extracted, for the search of transcripts differentially expressed using RNAse protection assays and reverse transcriptase-polymerase chain reactions. We found no difference that could explain INS-driven thymocyte growth, in the pattern of transcripts for death/proliferation mediators, or for a series of growth factor receptors and transcriptional regulators known as essential for thymus development. Thymocyte suspensions from cultured lobes, stained for phenotype analysis by fluorescence activated cell sorting, showed a decreased staining for Notch1 protein at cell surfaces upon INS addition. We analyzed the expression of Notch-related elements, and observed the recruitment of a specific set of transcripts simultaneous and compatible with INS-driven thymocyte growth, namely, transcripts for Notch3, for its ligand Jagged2, and for Deltex1, a mediator of a poorly characterized alternative pathway downstream of the Notch receptor.

Good quality parenting programmes and the home to school transition

Evidence Review 1 - Good quality parenting programmes and the home to school transition Briefing 1a - Good Quality Parenting Programmes Briefing 1b - Improving the Home to School Transition This set of documents, commissioned by Public Health England (PHE£0, and written by the UCL Institute of Health Equity, address the effects of parenting and good transition on the health and wellbeing of children aged 0-5. They also provide case studies, and examples of good practice for local areas. Evaluations from the UK and other countries show a positive effect of parenting interventions on outcomes and behaviours that we know are linked to positive health and development outcomes for children. Home to school transition programmes can be effective in improving the outcomes for children from more disadvantaged socio-economic groups more than for children from more advantaged socio-economic groups, although longer term impact on health inequalities can only be inferred because the impact on health has not been studied. The full evidence review and two shorter summary briefings are available to download above. This document is part of a series. An overview document which provides an introduction to this and other documents in the series, and links to the other topic areas, is available on the ‘Local Action on health inequalities’ project page. A video of Michael Marmot introducing the work is also available on our videos page.

Building a Transition Community

Footprints is developing a Transition Community Initiative which will be another distinct area of work within the Healthy Living Project, as part of the group's ongoing endeavours to influence change within the Colin community, tackling health inequalities. The Building a Transition Community Initiative oversees the development of the grounds at Footprints Women's Centre and offers food growing training to local residents who will be encouraged to volunteer in the garden. A local gardener has been hired and oversees the development and training of the volunteers. The project will grow fruit and vegetables within the grounds of Footprints Women's Centre and this produce will be used within the Footprints Catering Services. Any supplies surplus to requirements will be used in schools in the neighbourhood. Skills learned by the volunteers will also be transferred to their gardens at home throughout the Colin neighbourhood. The aim is also to demonstrate how participation in this project will increase and improve the physical activity levels and mental wellbeing of residents. Part of theDemonstration Programme 2010-2012 Initiative Type Community Food Growing Projects Location Antrim Target Groups Women Partner Agencies safefood

Surgical outcomes following repeat non-penetrating glaucoma filtration surgery at a tertiary referral centre

Purpose:To determine the surgical outcomes of patients undergoing repeat deep sclerectomies with collagen implant (DSCI) at a tertiary referral centre. Methods:The medical notes of 208 patients undergoing multiple DSCI were reviewed. Those undergoing repeat DSCI were identified and post operative data for each DSCI were analysed. Group A: the first DSCI; group B: second DSCI; group C: third DSCI. Results:Mean age was 66.8 ±13.0 years. At 12 months, percentage of mean IOP reduction in groups were 18%, 24% and 17% respectively. Mean interval to starting glaucoma medications, re-operation, mitomycin injection and goniopuncture all decreased as the number of operations increased. There was a significant reduction in complete success rates between groups A and B and groups B and C. Few minor complications were observed in all 3 groups. Conclusions:Despite the possibility of bleb independent outflow pathways in patients undergoing non-penetrating surgery, there are significantly reduced success rates in eyes undergoing repeat DSCI. This has important implications for the choice of subsequent operations in patients who have failed non-penetrating filtration surgery.

Supporting A Better Transition From Second Level To Higher Education: Key directions and Next Steps

Supporting A Better Transition From Second Level To Higher Education. Provided by the Department of Education and Skills, Ireland.

Early Carboniferous age of the Versoyen ophiolites and consequences: non-existence of a "Valais ocean'' (Lower Penninic, western Alps)

Ophiolites occur at several places in the Lower Penninic of the W and Central Alps. They are generally ascribed to oceanic crust of a so-called ``Valais ocean'' of Cretaceous age which plays a fundamental role in many models of Alpine paleogeography and geodynamics. The type locality and only observational base for the definition of a ``Valais ocean'' in the W Alps is the Versoyen ophiolitic complex, on the French-Italian boundary W of the Petit St-Bernard col. The idea of a "Valais ocean'' is based on two propositions that are since 40 years the basis for most reconstructions of the Lower Penninic: (1) The Versoyen forms the (overturned) stratigraphic base of the Cretaceous-Tertiary Valais-Tarentaise series; and (2) it has a Cretaceous age. We present new field and isotopic data that severely challenge both propositions. (1) The base of the Versoyen ophiolite is a thrust. It overlies a wildflysch with blocks of Versoyen rocks, named the Mechandeur Formation. This ``supra-Tarentaise'' wildflysch has been confused with an (overturned) stratigraphic transition from the Versoyen to the Valais-Tarentaise series. Thus the contact Versoyen/Tarentaise is not stratigraphic but tectonic, and the Versoyen ophiolite has no link with the Valais basin. This thrust corresponds to an inverse metamorphic discontinuity and to an abrupt change in tectonic style. (2) The contact of the Versoyen complex with the overlying Triassic-Jurassic Petit St-Bernard (PSB) series is stratigraphic (and not tectonic as admitted by all authors since 50 years). Several types of sedimentary structures polarize it and show that the PSB series is younger than the Versoyen. Consequently the Versoyen ophiolitic complex is Paleozoic and forms the basement of the PSB Mesozoic sediments. They both belong to a single tectonic unit, named the Versoyen-Petit St-Bernard nappe. (3) Ion microprobe U-Pb isotopic data on zircons from the main gabbroic intrusion in the Versoyen complex give a crystallization age of 337.0 +/- 4.1 Ma (Visean, Early Carboniferous). These zircons show typical oscillatory zoning and no overgrowth or corrosion. and are interpreted to date the Versoyen magmatism. These U-Pb data are in excellent agreement with our field observations and confirm the Paleozoic age of the Versoyen ophiolite. The existence of a ``Valais ocean'' of Cretaceous age in the W Alps becomes very improbable. The eclogite facies metamorphism of the Versoyen-Petit St-Bernard nappe results from an Alpine intra-continental subduction, guided by a Paleozoic oceanic suture. This is an example of the lone term influence of inherited deep-seated structures on a Much younger orogeny. This might well be a major cause of of the inherent complexity of the Alps.

A new scenario for the Domerian-Toarcian transition

In contrast to the majority of recently published hypotheses, we believe that the main trigger for early Toarcian anoxia is neither increased primary productivity during the Tenuicostatum and Falciferum Zones nor sudden methane hydrate degassing close to the transition between these two zones. In our opinion, this peculiar paleoceanographic episode is linked to a major, though short-lived, regression at the end of Upper Domerian. Sea-level fall resulted from sudden cooling due to increased volcanic activity. This generated global thermal insulation and subsequent glaciation. The regression is responsible for a major hiatus over NW-European epicontinental seas and is later followed by the well-known Lower Toarcian transgression. The interval corresponding to this hiatus allowed vegetation to colonise vast newly emerged surfaces. The leaching and drowning of the accumulated organo-humic matter then triggered the anoxic cycle at the transgressive maximum, concomitant with a global warming.