967 research outputs found

    PADAMOT : project overview report

    Get PDF
    Background and relevance to radioactive waste management International consensus confirms that placing radioactive wastes and spent nuclear fuel deep underground in a geological repository is the generally preferred option for their long-term management and disposal. This strategy provides a number of advantages compared to leaving it on or near the Earth’s surface. These advantages come about because, for a well chosen site, the geosphere can provide: • a physical barrier that can negate or buffer against the effects of surface dominated natural disruptive processes such as deep weathering, glaciation, river and marine erosion or flooding, asteroid/comet impact and earthquake shaking etc. • long and slow groundwater return pathways from the facility to the biosphere along which retardation, dilution and dispersion processes may operate to reduce radionuclide concentration in the groundwater. • a stable, and benign geochemical environment to maximise the longevity of the engineered barriers such as the waste containers and backfill in the facility. • a natural radiation shield around the wastes. • a mechanically stable environment in which the facility can be constructed and will afterwards be protected. • an environment which reduces the likelihood of the repository being disturbed by inadvertent human intrusion such as land use changes, construction projects, drilling, quarrying and mining etc. • protection against the effects of deliberate human activities such as vandalism, terrorism and war etc. However, safety considerations for storing and disposing of long-lived radioactive wastes must take into account various scenarios that might affect the ability of the geosphere to provide the functionality listed above. Therefore, in order to provide confidence in the ability of a repository to perform within the deep geological setting at a particular site, a demonstration of geosphere “stability” needs to be made. Stability is defined here to be the capacity of a geological and hydrogeological system to minimise the impact of external influences on the repository environment, or at least to account for them in a manner that would allow their impacts to be evaluated and accounted for in any safety assessments. A repository should be sited where the deep geosphere is a stable host in which the engineered containment can continue to perform according to design and in which the surrounding hydrogeological, geomechanical and geochemical environment will continue to operate as a natural barrier to radionuclide movement towards the biosphere. However, over the long periods of time during which long-lived radioactive wastes will pose a hazard, environmental change at the surface has the potential to disrupt the stability of the geosphere and therefore the causes of environmental change and their potential consequences need to be evaluated. As noted above, environmental change can include processes such as deep weathering, glaciation, river and marine erosion. It can also lead to changes in groundwater boundary conditions through alternating recharge/discharge relationships. One of the key drivers for environmental change is climate variability. The question then arises, how can geosphere stability be assessed with respect to changes in climate? Key issues raised in connection with this are: • What evidence is there that 'going underground' eliminates the extreme conditions that storage on the surface would be subjected to in the long term? • How can the additional stability and safety of the deep geosphere be demonstrated with evidence from the natural system? As a corollary to this, the capacity of repository sites deep underground in stable rock masses to mitigate potential impacts of future climate change on groundwater conditions therefore needs to be tested and demonstrated. To date, generic scenarios for groundwater evolution relating to climate change are currently weakly constrained by data and process understanding. Hence, the possibility of site-specific changes of groundwater conditions in the future can only be assessed and demonstrated by studying groundwater evolution in the past. Stability of groundwater conditions in the past is an indication of future stability, though both the climatic and geological contexts must be taken into account in making such an assertion

    Deaf-1 regulates epithelial cell proliferation and side-branching in the mammary gland

    Get PDF
    BACKGROUND: The transcription factor DEAF-1 has been identified as a high affinity binding partner of the LIM-only protein LMO4 that plays important roles in mammary gland development and breast cancer. Here we investigated the influence of DEAF-1 on human and mouse mammary epithelial cells both in vitro and in vivo and identified a potential target gene. RESULTS: Overexpression of DEAF-1 in human breast epithelial MCF10A cells enhanced cell proliferation in the mammary acini that develop in 3D cultures. To investigate the effects of Deaf-1 on mammary gland development and oncogenesis, we generated MMTV-Deaf-1 transgenic mice. Increased ductal side-branching was observed in young virgin mammary glands, accompanied by augmented cell proliferation. In addition, the ratio of the progesterone receptor isoforms PRA and PRB, previously implicated in regulating ductal side-branching, was altered. Affymetrix gene profiling studies revealed Rac3 as a potential target gene and quantitative RT-PCR analysis confirmed that Rac3 was upregulated by Deaf-1 in immortalized mouse mammary epithelial cells. Furthermore, MMTV-Deaf-1 transgenic mammary glands were found to have elevated levels of Rac3 mRNA, suggesting that it is a bona fide target. CONCLUSION: We have demonstrated that overexpression of Deaf-1 enhances the proliferation of human breast epithelial cells in vitro and mouse epithelial cells in vivo. Transgenic mammary glands overexpressing Deaf-1 exhibited a modest side-branching phenotype, accompanied by an increase in the number of BrdU-positive cells and a decrease in the proportion of PRA-expressing cells. Although proliferation was enhanced in Deaf-1 transgenic mice, overexpression of this gene was not sufficient to induce the formation of mammary tumors. In addition, our studies identified Rac3, encoding a small Rho-like GTPase, as a potential target of Deaf-1 in mouse mammary epithelial cells

    The Landscape of Videofluoroscopy in the UK: A Web-Based Survey

    Get PDF
    Videofluoroscopy (VFS) is considered one of the gold-standard assessments of swallowing. Whilst guidelines for the application and conduct of VFS exist, their translation into clinical practice remain challenging. To build a greater understanding on how VFS clinics operate in the UK. A web-based survey was shared with speech and language therapists (SLTs) working in VFS clinics via professional networks and social media from October 2018 to January 2019. 101 responses were received. Two thirds of clinics were SLT-led, with the majority of clinics being run by two SLTs (73.6%) and a radiographer (95.5%) also known as radiologic technologists, diagnostic radiographers and medical radiation technologists. Less than 50% of radiographers had received specialist training. Around half of the clinics used a standard assessment or analysis protocol and 88.1% a rating scale. Set recipes for a range of textures were used in 53.4% of VFS clinics. Barium and water soluble contrasts were used, but only 15.8% knew the concentration of contrast used. The most commonly reported VFS pulse and frame rate was 15 per second. There was evidence of a lack of SLT knowledge regarding technical operation of VFS. Screening times varied from 0.7–10 min (median 3 min, IQR 2.5–3.5). Around 50% of respondents reported quality issues affecting analysis. In a survey of UK SLTs, translation of VFS guidance into practice was found to be limited which may impact on the quality of assessment and analysis. Collaboration with radiology, strengthening of guidelines and greater uptake of specialist training is deemed essential

    The X-ray emission from Nova V382 Velorum: I. The hard component observed with BeppoSAX

    Get PDF
    We present BeppoSAX observations of Nova Velorum 1999 (V382 Vel), done in a broad X-ray band covering 0.1-300 keV only 15 days after the discovery and again after 6 months. The nova was detected at day 15 with the BeppoSAX instruments in the energy range 1.8-10 keV and we attribute the emission to shocks in the ejecta. The plasma temperature was kT~6 keV and the unabsorbed flux was F(x)~4.3 x 10(-11) erg/cm**2/s. The nebular material was affected by high intrinsic absorption of the ejecta. 6 months after after the outburst, the intrinsic absorption did not play a role, the nova had turned into a bright supersoft source, and the hot nebular component previously detected had cooled to a plasma temperature kT<=1 keV. No emission was detected in either observation above 20 keV.Comment: 1 tex file, 2 figures as .ps, and 1 .sty file of MNRA

    Therapeutic potential of transdermal glyceryl trinitrate in the management of acute stroke

    Get PDF
    The nitric oxide donor, glyceryl trinitrate (GTN), is a candidate treatment for the management of acute stroke with haemodynamic and potential reperfusion and neuroprotective effects. When administered as a transdermal patch during the acute and subacute phases after stroke, GTN was safe, lowered blood pressure, maintained cerebral blood flow, and did not induce cerebral steal or alter functional outcome. However, when given within 6 h of stroke onset, GTN reduced death and dependency (odds ratio 0.52; 95% confidence interval 0.34–0.78), death, disability, cognitive impairment and mood disturbance, and improved quality of life (data from two trials, n = 312). In a pooled analysis of four studies (n = 186), GTN reduced between-visit systolic blood pressure variability over days 1–7 compared with no GTN (mean difference -2.09; 95% confidence interval -3.83 to -0.35; p = 0.019). The efficacy of GTN given in the ultra-acute/pre-hospital setting is currently being assessed and, if found to be beneficial, the implications for hyperacute stroke practice are significant. Here, we discuss the evidence to date, potential mechanisms of action and future possibilities, including unanswered questions, for the therapeutic potential of GTN in acute stroke

    Introducing a trauma-informed capability approach in youth services

    Get PDF
    Trauma-informed practice has been developing for decades, though much remains unknown regarding how it is understood and practised. Drawing upon focus group data from an evaluation of a trauma-informed approach (TIA) implemented by an organisation in Southeast England, this paper provides a unique perspective of 31 staff members and 18 young people. Results indicate how choice and control, key elements of a TIA, align with the Capability Approach (CA). The CA is then used as a novel analytic framework to examine the data. A ‘Trauma-Informed Capabilities Approach’ is introduced as a holistic, person-centred way of conceptualising young trauma survivors’ wellbeing

    A Search for Peculiar Objects with the NASA Orbital Debris Observatory 3-m Liquid Mirror Telescope

    Get PDF
    The NASA Orbital Debris Observatory (NODO) astronomical survey uses a transit 3-m liquid mirror telescope to observe a strip of sky in 20 narrow-band filters. In this article, we analyze a subset of data from the 1996 observing season. The catalog consists of 18,000 objects with 10<V<19 observed in 10 narrow-band filters ranging from 500 nm to 950 nm. We first demonstrate the reliability of the data by fitting the Bahcall-Soneira model of the Galaxy to the NODO magnitude counts and color counts at various galactic latitudes. We then perform a hierarchical clustering analysis on the sample to extract 206 objects, out of a total of 18,000, showing peculiar spectral energy distributions. It is a measure of the reliability of the instrument that we extract so few peculiar objects. Although the data and results, per se, may not seem otherwise particularly remarkable, this work constitutes a milestone in optical astronomy since this is the first article that demonstrates astromomical research with a radically new type of mirror.Comment: 24 pages, 15 figures, 3 tables, gzipped-Postscript Revised version 27/04, added references and changed conten

    A review of the surgical conversion rate and independent management of spinal extended scope practitioners in a secondary care setting

    Get PDF
    INTRODUCTION Spinal orthopaedic triage aims to reduce unnecessary referrals to surgical consultants, thereby reducing waiting times to be seen by a surgeon and to surgical intervention. This paper presents an evaluation of a spinal orthopaedic triage service in the third largest spinal unit in the UK. METHODS A retrospective service evaluation spanning 2012 to 2014 was undertaken by members of the extended scope practitioner (ESP) team to evaluate the ESPs’ ability to manage patient care independently and triage surgical referrals appropriately. Data collected included rates of independent management, referral rates for surgical consideration and conversion to surgery. Patient satisfaction rates were evaluated retrospectively from questionnaires given to 5% of discharged patients. RESULTS A total of 2,651 patients were seen. The vast majority (92%) of all referrals seen by ESPs were managed independently. Only 8% required either a discussion with a surgeon to confirm management or for surgical review. Of the latter, 81% were considered to be suitable surgical referrals. A 99% satisfaction rate was reported by discharged patients. CONCLUSIONS ESP services in a specialist spinal service are effective in managing spinal conditions conservatively and identifying surgical candidates appropriately. Further research is needed to confirm ESPs’ diagnostic accuracy, patient outcomes and cost effectiveness

    The structure of Chariklo's rings from stellar occultations

    Get PDF
    Two narrow and dense rings (called C1R and C2R) were discovered around the Centaur object (10199) Chariklo during a stellar occultation observed on 2013 June 3. Following this discovery, we planned observations of several occultations by Chariklo's system in order to better characterize the physical properties of the ring and main body. Here, we use 12 successful occulations by Chariklo observed between 2014 and 2016. They provide ring profiles (physical width, opacity, edge structure) and constraints on the radii and pole position. Our new observations are currently consistent with the circular ring solution and pole position, to within the ¹3.3\pm 3.3 km formal uncertainty for the ring radii derived by Braga-Ribas et al. The six resolved C1R profiles reveal significant width variations from ∟5\sim 5 to 7.5 km. The width of the fainter ring C2R is less constrained, and may vary between 0.1 and 1 km. The inner and outer edges of C1R are consistent with infinitely sharp boundaries, with typical upper limits of one kilometer for the transition zone between the ring and empty space. No constraint on the sharpness of C2R's edges is available. A 1σ\sigma upper limit of ∟20\sim 20 m is derived for the equivalent width of narrow (physical width <4 km) rings up to distances of 12,000 km, counted in the ring plane
    • …
    corecore