Methylthiolate-induced reconstruction of Ag(1 1 1): A medium energy ion scattering study

Medium energy ion scattering (MEIS), using 100 keV H+ incident ions, has been used to investigate the structure of the Ag(1 1 1)(√7 × √7)R19° –CH3S surface phase. The results provide the first direct evidence that this structure does involve substantial reconstruction of the Ag surface layer. The measured absolute scattered ion yields and blocking curves are in generally good agreement with a specific structural model of the surface based on a reconstructed layer containing 3/7 ML Ag atoms, previously suggested on the basis of scanning tunnelling microscopy (STM) and normal incidence X-ray standing wave (NIXSW) studies. However, the MEIS data indicate that any rumpling of the thiolate layer, is small, and probably 0.2 Å. This value is smaller than the amplitude suggested in the STM and NIXSW studies, but could be entirely consistent with the earlier experimental data

MEIS investigations of surface structure

The early work of the FOM-AMOLF group in Amsterdam clearly demonstrated the potential of medium energy ion scattering (MEIS), typically using 100 keV H+ incident ions, to investigate the structure of surfaces, but most current applications of the method are focussed on near-surface compositional studies of non-crystalline films. However, the key strengths of the MEIS technique, notably the use of blocking curves in double-alignment experiments and absolute yield measurements, are extremely effective in providing detailed near-surface structural information for a wide range of crystalline materials. This potential and the underlying methodology, is illustrated through examples of applications to the study of layer-dependent composition and structure in alloy surfaces, in studies of the surface crystallography of an oxide surface (rutile TiO2(1 1 0)) and in investigations of complex adsorbate-induced reconstruction of metal surfaces, including the pseudo-(1 0 0) reconstruction of Cu(1 1 1) induced by adsorption of atomic N and molecular methylthiolate (CH3S–). In addition to the use of calibrated blocking curves, the use of the detailed spectral shape of the surface peak in the scattered ion energy spectra, as a means of providing single-atomic layer resolution of the surface structure, is also discussed

The structure of epitaxial V2O3 films and their surfaces : a medium energy ion scattering study

Medium energy ion scattering, using 100 keV H+ incident ions, has been used to investigate the growth of epitaxial films, up to thicknesses of ~200 Å, of V2O3 on both Pd(111) and Au(111). Scattered-ion energy spectra provide a measure of the average film thickness and the variations in this thickness, and show that, with suitable annealing, the crystalline quality is good. Plots of the scattering yield as a function of scattering angle, so-called blocking curves, have been measured for two different incidence directions and have been used to determine the surface structure. Specifically, scattering simulations for a range of different model structures show poor agreement with experiment for half-metal (….V’O3V) and vanadyl (….V’O3V=O) terminations, with and without surface interlayer relaxations. However, good agreement with experiment is found for the modified oxygen-termination structure, first proposed by Kresse et al., in which a subsurface V half-metal layer is moved up into the outermost V buckled metal layer to produce a VO2 overlayer on the underlying V2O3, with an associated layer structure of ….O3VV’’V’O3

Deconstructing density: strategic dilemmas confronting the post-Apartheid city

Public authorities in many countries around the world are seeking to raise urban densities. Residential densification is particularly important in South Africa because of the colonial and apartheid legacy of sprawling, fragmented, racially divided cities. The paper examines the case for densifying central Cape Town and provides a framework to help deconstruct the concept and explore the policy challenges faced. It focuses on the bold aim to treble the area’s population within 10 years, and identifies issues where further consideration and public debate are required for how this can be achieved in a way that is desirable, affordable and fair. A key message is the need to understand both the composition of demand for central city living and the challenges involved in supplying suitable housing and amenities at higher densities. The level of social inequality in the city poses greater complications than elsewhere

Scenario planning for the Edinburgh city region

This paper examines the application of scenario planning techniques to the detailed and daunting challenge of city re-positioning when policy makers are faced with a heavy history and a complex future context. It reviews a process of scenario planning undertaken in the Edinburgh city region, exploring the scenario process and its contribution to strategies and policies for city repositioning. Strongly rooted in the recent literature on urban and regional economic development, the text outlines how key individuals and organisations involved in the process participated in far-reaching analyses of the possible future worlds in which the Edinburgh city region might find itself

Exploring Public Perceptions and Understanding of Dementia: Analysing Narratives from the Mass Observation Project

Over 850,000 people living in the United Kingdom have been diagnosed with dementia, yet knowledge about this condition amongst the general population remains relatively poor. Many studies have evaluated the level of public knowledge and understanding about dementia from a research and professional service perspective, however none have considered this condition from the perspective of the wider public. In this preliminary overview, we analyse and describe high level narratives collected from 143 respondents to a dementia Directive commissioned to the Mass Observation Project. These narratives present a perspective on the public knowledge and understanding about dementia not previously considered, where respondents have written openly about their own experiences, and reflected on their perception of the wider public’s knowledge and understanding about dementia. This unique perspective importantly enhances our knowledge about the public’s understanding and awareness of dementia, and informs the main areas of public concern found in the analysis: care responsibilities, impact on relationships, and fears about developing dementia

Luminous Red Galaxy Clustering at z~0.7 - First Results using AAOmega

We report on the AAT-AAOmega LRG Pilot observing run to establish the feasibility of a large spectroscopic survey using the new AAOmega instrument. We have selected Luminous Red Galaxies (LRGs) using single epoch SDSS riz-photometry to i<20.5 and z<20.2. We have observed in 3 fields including the COSMOS field and the COMBO-17 S11 field, obtaining a sample of ~600 redshift z>=0.5 LRGs. Exposure times varied from 1 - 4 hours to determine the minimum exposure for AAOmega to make an essentially complete LRG redshift survey in average conditions. We show that LRG redshifts to i<20.5 can measured in approximately 1.5hr exposures and present comparisons with 2SLAQ and COMBO-17 (photo-)redshifts. Crucially, the riz selection coupled with the 3-4 times improved AAOmega throughput is shown to extend the LRG mean redshift from z=0.55 for 2SLAQ to z=0.681+/- 0.005 for riz-selected LRGs. This extended range is vital for maximising the S/N for the detection of the baryon acoustic oscillations (BAOs). Furthermore, we show that the amplitude of LRG clustering is s_0 = 9.9+/-0.7 h^-1 Mpc, as high as that seen in the 2SLAQ LRG Survey. Consistent results for the real-space amplitude are found from projected and semi-projected correlation functions. This high clustering amplitude is consistent with a long-lived population whose bias evolves as predicted by a simple ``high-peaks'' model. We conclude that a redshift survey of 360 000 LRGs over 3000deg^2, with an effective volume some 4 times bigger than previously used to detect BAO with LRGs, is possible with AAOmega in 170 nights.Comment: 12 pages, 7 figures, 8 tables, minor changes, matches published versio

What is current practice in offering debriefing services to post partum women and what are the perceptions of women in accessing these services: A critical review of the literature

Objective: The main research question is to describe current practice in offering debriefing services to postpartum women and learn about the perceptions of women accessing these services Design: Critical review of the literature using a meta ethnography approach. Findings: Twenty papers were identified. These included four surveys, three qualitative studies, one mixed methods study and three literature reviews. Nine randomised controlled trials (RCTs) provided additional information from alongside surveys and description of interventions. Two types of debriefing were identified: structured and unstructured. The more formal psychoanalytic forms took place within the RCTs whilst the unstructured discussion sessions commonly with midwives were identified in other research papers. In addition there is confusion amongst service providers about the nature of debriefing and what is delivered. Various aspects of providing a postnatal debriefing service were identified including the optimal timing, specific groups offered debriefing and the number of sessions offered. Postnatal debriefing enabled women to have their birth experiences validated by talking and being listened to and being provided with information. Finally from the limited literature identified relating to midwives’ perceptions of postnatal debriefing there was an overall feeling from midwives that they considered it to be beneficial to women. Key conclusions: The findings of this literature review imply that women’s responses to receiving postnatal debriefing are generally positive. This review has found that women appear to value talking and being listened to by a midwife following birth. They seem to have a strong need to have their story heard. This discussion also allows the women to have questions answered and information given where necessary. The whole process places a seal on a woman’s birth experience which is validated. Implications for practice: Although there is no evidence to suggest that postnatal debriefing reduces morbidity, women find the service of value. Maternity providers should consider offering a postnatal debriefing service to meet those needs in advance of further research in this area

Regional responses to recession:the role of the West Midlands regional taskforce

Bailey D. and Berkeley N. Regional responses to recession: the role of the West Midlands Regional Taskforce, Regional Studies. Regional taskforces were set up across the English regions in late 2008 in response to the most severe recession since the Second World War. This paper examines the role of one such body, the West Midlands Regional Taskforce, as an example of regional response to recession, and offers potential lessons for the future in dealing with such situations. In so doing it reflects on the contested concept of regional 'resilience' and its relevance for policy actions at the regional level. Understanding how the region responded in this way could help in maintaining a 'permanent capacity' to deal with shocks, especially in the context of the abolition of regional development agencies (RDAs) in England from 2012 and their replacement with local enterprise partnerships (LEPs)

The MANGO study: a prospective investigation of oxygen enhanced and blood-oxygen level dependent MRI as imaging biomarkers of hypoxia in glioblastoma

BackgroundGlioblastoma (GBM) is the most aggressive type of brain cancer, with a 5-year survival rate of ~5% and most tumours recurring locally within months of first-line treatment. Hypoxia is associated with worse clinical outcomes in GBM, as it leads to localized resistance to radiotherapy and subsequent tumour recurrence. Current standard of care treatment does not account for tumour hypoxia, due to the challenges of mapping tumour hypoxia in routine clinical practice. In this clinical study, we aim to investigate the role of oxygen enhanced (OE) and blood-oxygen level dependent (BOLD) MRI as non-invasive imaging biomarkers of hypoxia in GBM, and to evaluate their potential role in dose-painting radiotherapy planning and treatment response assessment.MethodsThe primary endpoint is to evaluate the quantitative and spatial correlation between OE and BOLD MRI measurements and [18F]MISO values of uptake in the tumour. The secondary endpoints are to evaluate the repeatability of MRI biomarkers of hypoxia in a test-retest study, to estimate the potential clinical benefits of using MRI biomarkers of hypoxia to guide dose-painting radiotherapy, and to evaluate the ability of MRI biomarkers of hypoxia to assess treatment response. Twenty newly diagnosed GBM patients will be enrolled in this study. Patients will undergo standard of care treatment while receiving additional OE/BOLD MRI and [18F]MISO PET scans at several timepoints during treatment. The ability of OE/BOLD MRI to map hypoxic tumour regions will be evaluated by assessing spatial and quantitative correlations with areas of hypoxic tumour identified via [18F]MISO PET imaging.DiscussionMANGO (Magnetic resonance imaging of hypoxia for radiation treatment guidance in glioblastoma multiforme) is a diagnostic/prognostic study investigating the role of imaging biomarkers of hypoxia in GBM management. The study will generate a large amount of longitudinal multimodal MRI and PET imaging data that could be used to unveil dynamic changes in tumour physiology that currently limit treatment efficacy, thereby providing a means to develop more effective and personalised treatments