998 resultados para flexible portal frame


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The linear and nonlinear properties of low-frequency electrostatic excitations of charged dust particles (or defects) in a dense collisionless, unmagnetized Thomas-Fermi plasma are investigated. A fully ionized three-component model plasma consisting of electrons, ions, and negatively charged massive dust grains is considered. Electrons and ions are assumed to be in a degenerate quantum state, obeying the Thomas-Fermi density distribution, whereas the inertial dust component is described by a set of classical fluid equations. Considering large-amplitude stationary profile travelling-waves in a moving reference frame, the fluid evolution equations are reduced to a pseudo-energy-balance equation, involving a Sagdeev-type potential function. The analysis describes the dynamics of supersonic dust-acoustic solitary waves in Thomas-Fermi plasmas, and provides exact predictions for their dynamical characteristics, whose dependence on relevant parameters (namely, the ion-to-electron Fermi temperature ratio, and the dust concentration) is investigated. An alternative route is also adopted, by assuming weakly varying small-amplitude disturbances off equilibrium, and then adopting a multiscale perturbation technique to derive a Korteweg–de Vries equation for the electrostatic potential, and finally solving in terms for electric potential pulses (electrostatic solitons). A critical comparison between the two methods reveals that they agree exactly in the small-amplitude, weakly superacoustic limit. The dust concentration (Havnes) parameter h = Zd0nd0/ne0 affects the propagation characteristics by modifying the phase speed, as well as the electron/ion Fermi temperatures. Our results aim at elucidating the characteristics of electrostatic excitations in dust-contaminated dense plasmas, e.g., in metallic electronic devices, and also arguably in supernova environments, where charged dust defects may occur in the quantum plasma regime.

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Citizen participation is often valorised in the governance of areas of high scientific uncertainty at national, international and supranational levels. This chapter considers citizen or public participation in the specific area of the EU’s agenda on sustainable development as it increasingly frames technoscientific innovation and development. Specifically, the chapter focuses on just one underexplored aspect of the conditions of possibility for participation: imaginaries. These include how the EU imagines its engagement, responsibilities and identity in relation to the specific area, including the knowledges that are constructed and used in decision-making, and by implication the role of citizen or public participation.

The discussion draws on an analysis of the social and technoscientific imaginaries found in legal, regulatory and policy discourses. These construct the frame of sustainable development and build a link between it and technoscientific innovation and development. By attention to imaginaries as one aspect of the frame, the chapter highlights the centrality of, and main interactions between, sustainable development in the inscription and potential disruption of the normative and programmatic background for the operationalisation of technoscientific innovation. These insights are used to highlight how imaginaries constitute a crucial aspect of the conditions of possibility for participation: determining who has to participate in decision-making through configurations of ‘citizen’ or ‘public’, how, why, and which outcomes are to be achieved by that participation.

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A study undertaken at the University of Liverpool has investigated the potential for using construction and demolition waste (C&DW) derived aggregate in the manufacture of a range of precast concrete products, i.e. building and paving blocks and pavement flags. Phase III, which is reported here, investigated
concrete pavement flags. This was subsequent to studies on building and paving blocks. Recycled demolition aggregate can be used to replace newly quarried limestone aggregate, usually used in coarse (6 mm) and fine (4 mm-to-dust) gradings. The first objective was, as was the case with concrete building
and paving blocks, to replicate the process used by industry in fabricating concrete pavement flags in the laboratory. The ‘‘wet’’ casting technique used by industry for making concrete flags requires a very workable mix so that the concrete flows into the mould before it is compressed. Compression squeezes out water from the top as well as the bottom of the mould. This industrial casting procedure was successfully replicated in the laboratory by using an appropriately modified cube crushing machine and a special mould typical of what is used by industry. The mould could be filled outside of the cube crushing machine and then rolled onto a steel frame and into the machine for it to be compressed. The texture and mechanical properties of the laboratory concrete flags were found to be similar to the factory ones. The experimental work involved two main series of tests, i.e. concrete flags made with concrete- and
masonry-derived aggregate. Investigation of flexural strength was required for concrete paving flags. This is different from building blocks and paving blocks which required compressive and tensile splitting strength respectively. Upper levels of replacement with recycled demolition aggregate were determined
that produced similar flexural strength to paving flags made with newly quarried aggregates, without requiring an increase in the cement content. With up to 60% of the coarse or 40% of the fine fractions replaced with concrete-derived aggregates, the target mean flexural strength of 5.0 N/mm2 was still
achieved at the age of 28 days. There was similar detrimental effect by incorporating the fine masonry-derived aggregate. A replacement level of 70% for coarse was found to be satisfactory and also conservative. However, the fine fraction replacement could only be up to 30% and even reduced to 15% when used for mixes where 60% of the coarse fraction was also masonry-derived aggregate.

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This paper describes the result of a project to develop climate adaptation design strategies funded by the UK’s Technology Strategy Board. The aim of the project was to look at the effects of climate change in the distant future (2080) on a vulnerable group such as older people with special needs and see how architectural design strategies and technologies may be used today to help mitigate problems ahead caused by climate change.
Older people are the most vulnerable sector of society and are particularly at risk in extreme weather, either excess cold in winter or continual high temperatures in summer. In the UK it is predicted that average temperatures may rise by as much as 8 degrees in Summer by 2080 and there will be a 20% greater chance of extreme weather events. This will place extreme stress on the building stock which is designed for today’s mild maritime climate.
The project took a current proposal for an extra-care home for the elderly designed to 2010 regulations and developed a road map to 2080 using climate models developed by the UK Meteorological Office. This allowed the current design to be assessed using future climatic data, proposals for improvement of the scheme to be made within existing constraints and also a new scheme to be developed from first principals using this data, and projections of new technologies that will be available. By comparing these schemes, the approach allowed a reassessment of the initial scheme, and allowed a new design to be developed that offered a more flexible solution incorporating future retrofit which allows new renewable technologies for heating, cooling and water storage to be added at a later date.

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Q methodology was used to enable the identification of discourses among stakeholders to the environmental and resource dimensions of sustainability policies and to gain an understanding of the usefulness of Q methodology in informing sustainability policy development. The application of Q methodology has been useful in identifying shared discourses between different stakeholder groups, and providing insights into how stakeholders frame or understand policy issues; and recommendations are made for ongoing research priorities. These insights, in turn, informed the choice of scenarios for an in parallel process of policy evaluation using Ecological and Carbon Footprinting.

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Paralytic shellfish poisoning is a toxic syndrome described in humans following the ingestion of seafood contaminated with saxitoxin and/or its derivatives. The presence of these toxins in shellfish is considered an important health threat and their levels in seafood destined to human consumption are regulated in many countries, as well as the levels of other chemically unrelated toxins. We studied the feasibility of immunodetection of saxitoxin and its analogs using a solid-phase microsphere assay coupled to flow cytometry detection in a Luminex 200 system. The technique consists of a competition assay where the toxins in solution compete with bead-bound saxitoxin for binding to an antigonyautoxin 2/3 monoclonal antibody (GT-13A). The assay allowed the detection of saxitoxin both in buffer and mussel extracts in the range of 2.2-19.7 ng/mL (IC(20)-IC(80)). Moreover, the assay cross-reactivity with other toxins of the group is similar to previously published immunoassays, with adequate detection of most analogs except N-1 hydroxy analogs. The recovery rate of the assay for saxitoxin was close to 100%. This microsphere-based immunoassay is suitable to be used as a screening method, detecting saxitoxin from 260 to 2360 µg/kg. This microsphere/flow cytometry system provided similar sensitivities to previously published immunoassays and provides a solid background for the development of easy, flexible multiplexing of toxin detection in one sample.

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A DNA sequence encoding a protein with predicted EF-hand and dynein light chain binding domains was identified in a Fasciola hepatica EST library. Sequence analysis of the encoded protein revealed that the most similar known protein was the Fasciola gigantica protein FgCaBP3 and so this newly identified protein was named FhCaBP3. Molecular modelling of FhCaBP3 predicted a highly flexible N-terminal region, followed by a domain containing two EF-hand motifs the second of which is likely to be a functioning divalent ion binding site. The C-terminal domain of the protein contains a dynein light chain like region. Interestingly, molecular modelling predicts that calcium ion binding to the N-terminal domain destabilises the ß-sheet structure of the C-terminal domain. FhCaBP3 can be expressed in, and purified from, Escherichia coli. The recombinant protein dimerises and the absence of calcium ions appeared to promote dimerisation. Native gel shift assays demonstrated that the protein bound to calcium and manganese ions, but not to magnesium, barium, zinc, strontium, nickel, copper or cadmium ions. FhCaBP3 interacted with the calmodulin antagonists trifluoperazine, N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide and chlorpromazine as well as the myosin regulatory light chain-binding drug praziquantel. Despite sequence and structural similarities to other members of the same protein family from F. hepatica, FhCaBP3 has different biochemical properties to the other well characterised family members, FH22 and FhCaBP4. This suggests that each member of this trematode calcium-binding family has discrete functional roles within the organism.

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Objective: to identify non-invasive interventions in the perinatal period that could enable midwives to offer effective support to women within the area of maternal mental health and well-being.

Methods: a total of 9 databases were searched: MEDLINE, PubMed, EBSCO (CINAHL/British Nursing Index), MIDIRS Online Database, Web of Science, The Cochrane library, CRD (NHS EED/DARE/HTA), Joanne Briggs Institute and EconLit. A systematic search strategy was formulated using key MeSH terms and related text words for midwifery, study aim, study design and mental health. Inclusion criteria were articles published from 1999 onwards, English language publications and articles originating from economically developed countries, indicated by membership of the Organisation for Economic Co-operation and Development (OECD). Data were independently extracted using a data collection form, which recorded data on the number of papers reviewed, time frame of the review, objectives, key findings and recommendations. Summary data tables were set up outlining key data for each study and findings were organised into related groups. The methodological quality of the reviews was assessed based on predefined quality assessment criteria for reviews.

Findings: 32 reviews were identified as examining interventions that could be used or co-ordinated by midwives in relation to some aspect of maternal mental health and well-being from the antenatal to the postnatal period and met the inclusion criteria. The review highlighted that based on current systematic review evidence it would be premature to consider introducing any of the identified interventions into midwifery training or practice. However there were a number of examples of possible interventions worthy of further research including midwifery led models of care in the prevention of postpartum depression, psychological and psychosocial interventions for treating postpartum depression and facilitation/co-ordination of parent-training programmes. No reviews were identified that supported a specific midwifery role in maternal mental health and well-being in pregnancy, and yet, this is the point of most intensive contact.

Key conclusions and implications for practice: This systematic review of systematic reviews provides a valuable overview of the current strengths and gaps in relation to maternal mental health interventions in the perinatal period. While there was little evidence identified to inform the current role of midwives in maternal mental health, the review provides the opportunity to reflect on what is achievable by midwives now and in the future and the need for high quality randomised controlled trials to inform a strategic approach to promoting maternal mental health in midwifery.

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The human telomeric DNA sequence with four repeats can fold into a parallel-stranded propeller-type topology. NMR structures solved under molecular crowding experiments correlate with the crystal structures found with crystal-packing interactions that are effectively equivalent to molecular crowding. This topology has been used for rationalization of ligand design and occurs experimentally in a number of complexes with a diversity of ligands, at least in the crystalline state. While G-quartet stems have been well characterised, the interactions of the TTA loop with the G-quartets are much less defined. To better understand the conformational variability and structural dynamics of the propeller-type topology, we performed molecular dynamics simulations in explicit solvent up to 1.5 µs. The analysis provides a detailed atomistic account of the dynamic nature of the TTA loops highlighting their interactions with the G-quartets including formation of an A:A base pair, triad, pentad and hexad. The results present a threshold in quadruplex simulations, with regards to understanding the flexible nature of the sugar-phosphate backbone in formation of unusual architecture within the topology. Furthermore, this study stresses the importance of simulation time in sampling conformational space for this topology.

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Background: This article describes a 'back to the future' approach to case 'write-ups', with medical students producing handwritten instead of word-processed case reports during their clinical placements. Word-processed reports had been found to have a number of drawbacks, including the inappropriate use of 'cutting and pasting', undue length and lack of focus. Method: We developed a template to be completed by hand, based on the hospital 'clerking-in process', and matched this to a new assessment proforma. An electronic survey was conducted of both students and assessors after the first year of operation to evaluate impact and utility. Results: The new template was well received by both students and assessors. Most students said they preferred handwriting the case reports (55.6%), although a significant proportion (44.4%) preferred the word processor. Many commented that the template enabled them to effectively learn the structure of a case history and to improve their history-taking skills. Most assessors who had previously marked case reports felt the new system represented an improvement. The average time spent marking each report fell from 23.56 to 16.38minutes using the new proforma. Discussion: Free text comments from the survey have led to the development of a more flexible case report template better suited to certain specialties (e.g. dermatology). This is an evolving process and there will be opportunities for further adaptation as electronic medical records become more common in hospital. © Blackwell Publishing Ltd 2012.

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High levels of As in groundwater commonly found in Bangladesh and other parts of Asia not only pose a risk via drinking water consumption but also a risk in agricultural sustainability and food safety. This review attempts to provide an overview of current knowledge and gaps related to the assessment and management of these risks, including the behaviour of As in the soil-plant system, uptake, phytotoxicity, As speciation in foods, dietary habits, and human health risks. Special emphasis has been given to the situation in Bangladesh, where groundwater via shallow tube wells is the most important source of irrigation water in the dry season. Within the soil-plant system, there is a distinct difference in behaviour of As under flooded conditions, where arsenite (AsIII) predominates, and under nonflooded conditions, where arsenate (AsV) predominates. The former is regarded as most toxic to humans and plants. Limited data indicate that As-contaminated irrigation water can result in a slow buildup of As in the topsoil. In some cases the buildup is reflected by the As levels in crops, in others not. It is not yet possible to predict As uptake and toxicity in plants based on soil parameters. It is unknown under what conditions and in what time frame As is building up in the soil. Representative phytotoxicity data necessary to evaluate current and future soil concentrations are not yet available. Although there are no indications that crop production is currently inhibited by As, long-term risks are clearly present. Therefore, with concurrent assessments of the risks, management options to further prevent As accumulation in the topsoil should already have been explored. With regard to human health, data on As speciation in foods in combination with food consumption data are needed to assess dietary exposure, and these data should include spatial and seasonal variability. It is important to control confounding factors in assessing the risks. In a country where malnutrition is prevalent, levels of inorganic As in foods should be balanced against the nutritional value of the foods. Regarding agriculture, As is only one of the many factors that may pose a risk to the sustainability of crop production. Other risk factors such as nutrient depletion and loss of organic matter also must be taken into account to set priorities in terms of research, management, and overall strategy.

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The design of a System-on-a-Chip (SoC) demonstrator for a baseline JPEG encoder core is presented. This combines a highly optimized Discrete Cosine Transform (DCT) and quantization unit with an entropy coder which has been realized using off-the-shelf synthesizable IP cores (Run-length coder, Huffman coder and data packer). When synthesized in a 0.35 µm CMOS process, the core can operate at speeds up to 100 MHz and contains 50 k gates plus 11.5 kbits of RAM. This is approximately 20% less than similar JPEG encoder designs reported in literature. When targeted at FPGA the core can operate up to 30 MHz and is capable of compressing 9-bit full-frame color input data at NTSC or PAL rates.

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In this article, we explore the extent to which a consideration of welfare regime and socioeconomic differences in poverty levels and patterns can assist us in making an informed assessment of alternative poverty indicators. Poverty in the EU is normally defined in terms of income thresholds at the level of each member state. However, with the enlargement of the EU, such measures have come in for increasing criticism. One set of reservation relates to the limitations imposed by an entirely national frame of reference. An alternative critique focuses on the fact that low income is an unreliable indicator of poverty. In this article, we seek to explore the strength of both arguments by comparing the outcomes associated with ‘at risk of poverty’ and consistent poverty at both national and EU levels. Developing an appropriate assessment of poverty levels in the enlarged EU, particularly in periods of rapid change, is likely to require that we make use of a number of indicators none of which capture the full complexity of cross-national poverty outcomes. However, our analysis suggests that if a choice is to be made between the available indicators, the ‘mixed consistent poverty’ indicator developed in this study is best suited to achieving the stated EU objective of assessing the scale of exclusion from minimally acceptable standards of living in individual countries while also measuring the extent to which the whole population of Europe is sharing in the benefits of high average prosperity.

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Long-standing concerns within the field of educational assessment consider the impact of assessment policy and practice as matters of equity, inequality and social justice.Yet educational assessment policy and practice continues to have powerful social consequences for key users such as children and young people.This paper re-positions these consequences as a matter of ethics.It uses the work of Messick to frame how ethical matters extend beyond test instruments into the realm of uses and impact. A case study of the 11+ school transfer system in Northern Ireland is presented to illustrate ethical dilemmas emerging as a consequence of actions and decisions of using assessment systems for particular purposes.In looking forward to how we might attend to ethical matters in assessment policy and practice, a consideration of a children’s rights approach is outlined that may provide a moral and legal framework for action.




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In this paper we address the question of the relative importance of within and between country differences in income and material deprivation in the European Union in the context of recent suggestions that insufficient attention has been paid to the latter. In particular, we respond to the argument that the 'state bounded' relative income approach obscures the significance of EU-wide reference groups. Making use of EU-SILC 2004, we have sought to quantify the magnitude of relevant within and between country differences and their relative impact. Overall, our analysis supports the view that the predominant frame of reference is a national one. The limited impact of European reference groups observed in our analysis does not require explanation in terms of the emergence of a European social stratification system. Furthermore, the significance of such comparisons depends not only on the expectations of those affected by European inequalities but on the degree of legitimacy afforded to ensuing demands. While an EU-wide income-threshold can provide information regarding progress of the Union towards greater social cohesion, its usage for this purpose does not require a strong sense of European identity. Given the current status of the European Social Model, it would seem unwise to attribute an undue degree of policy relevance to the relatively modest impact of EU-wide reference groups revealed in our analysis.