933 resultados para evolving
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Traditional methods of teaching and learning in higher education are ever-evolving. This report assesses the feasibility of developing a teaching aid for pharmacology modules. Focus groups were established to gauge student and staff opinions on the use of teaching aids and an extensive literature review was conducted. The study identifies and critically evaluates a range of possibilities that could be developed and discusses practical issues such as accessibility, inclusion and assessment, associated with these potential aids. This initial study concludes that a suitable aid could take the form of a student-led development of a wiki-type website resource that included access to case-studies giving students ‘real-life’ experience of the concepts being studied. This type of project requires considerable time and financial support; nevertheless, this idea could be extended for many drugs and could be used in any health science course.
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The electronic stopping power of H and He moving through gold is obtained to high accuracy using time-evolving density-functional theory, thereby bringing usual first principles accuracies into this kind of strongly coupled, continuum nonadiabatic processes in condensed matter. The two key unexplained features of what observed experimentally have been reproduced and understood: (i)The nonlinear behavior of stopping power versus velocity is a gradual crossover as excitations tail into the d-electron spectrum; and (ii)the low-velocity H/He anomaly (the relative stopping powers are contrary to established theory) is explained by the substantial involvement of the d electrons in the screening of the projectile even at the lowest velocities where the energy loss is generated by s-like electron-hole pair formation only. © 2012 American Physical Society.
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The Great Cave of Niah in Sarawak (northern Borneo) came into the gaze of Western Science through the work of Alfred Russell Wallace, who came to Sarawak in the 1850s to search for ‘missing links’ in his pioneering studies of evolution and the natural history of Island Southeast Asia and Australasia. The work of Tom and Barbara Harrisson in the 1950s and 1960s placed the Great Cave, and particularly their key find, the ‘Deep Skull’, at the nexus of the evolving archaeological framework for the region: for decades the skull, dated in 1958 by adjacent charcoal to c.40,000 BP, was the oldest fossil of an anatomically modern human anywhere in the world and thus critical to ideas about human evolution and dispersal. Although several authorities later questioned the provenance and antiquity of the Deep Skull, renewed investigations of the Harrisson excavations since 2000 have shown that it can be attributed securely to a specific location in the Pleistocene stratigraphy, with direct U-series dating on a piece of the skull indicating an age for it of c.37,500 BP and the first evidence for associated human activity at the site going back to c.50,000 BP. The new work also indicates that the skull is part of a cultural deposit, perhaps a precursor to the long tradition in Borneo of processing of the dead and secondary burial. These indicators of cultural complexity chime with the complexity of the subsistence behaviour of the early users of the caves discussed by Philip Piper and Ryan Rabett in chapter ten of this volume.
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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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DDR-SDRAM based data lookup techniques are evolving into a core technology for packet lookup applications for data network, benefitting from the features of high density, high bandwidth and low price of DDR memory products in the market. Our proposed DDR-SDRAM based lookup circuit is capable of achieving IP header lookup for network line-rates of up to 10Gbps, providing a solution on high-performance and economic packet header inspections. ©2008 IEEE.
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The use of genetic algorithms (GAs) for structural optimisation is well established but little work has been reported on the inclusion of damage variables within an optimisation framework. This approach is particularly useful in the optimisation of composite structures which are prone to delamination damage. In this paper a challenging design problem is presented where the objective was to delay the catastrophic failure of a postbuckling secondary-bonded stiffened composite panel susceptible to secondary instabilities. It has been conjectured for some time that the sudden energy release associated with secondary instabilities may initiate structural failure, but this has proved difficult to observe experimentally. The optimisation methodology confirmed this indirectly by evolving a panel displaying a delayed secondary instability whilst meeting all other design requirements. This has important implication in the design of thin-skinned lightweight aerostructures which may exhibit this phenomenon.
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The eye and the brain are prototypical tissues manifesting immune privilege (IP) in which immune responses to foreign antigens, particularly alloantigens are suppressed, and even completely inhibited. Explanations for this phenomenon are numerous and mostly reflect our evolving understanding of the molecular and cellular processes underpinning immunological responses generally. IP is now viewed as a property of many tissues and the level of expression of IP varies not only with the tissue but with the nature of the foreign antigen and changes in the limited conditions under which privilege can operate as a mechanism of immunological tolerance. As a result, IP functions normally as a homeostatic mechanism preserving normal function in tissues, particularly those with highly specialized function and limited capacity for renewal such as the eye and brain. However, IP is relatively easily bypassed in the face of a sufficiently strong immunological response, and the privileged tissues may be at greater risk of collateral damage because its natural defenses are more easily breached than in a fully immunocompetent tissue which rapidly rejects foreign antigen and restores integrity. This two-edged sword cuts its swathe through the eye: under most circumstances, IP mechanisms such as blood-ocular barriers, intraocular immune modulators, induction of T regulatory cells, lack of lymphatics, and other properties maintain tissue integrity; however, when these are breached, various degrees of tissue damage occur from severe tissue destruction in retinal viral infections and other forms of uveoretinal inflammation, to less severe inflammatory responses in conditions such as macular degeneration. Conversely, ocular IP and tumor-related IP can combine to permit extensive tumor growth and increased risk of metastasis thus threatening the survival of the host.
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The optimization of cutouts in composite plates was investigated by implementing a procedure known as Evolutionary Structural Optimization. Perforations were introduced into a finite element mesh of the plate from which one or more cutouts of a predetermined size were evolved. In the examples presented, plates were rejected from around each evolving cutout based on a predefined rejection criterion. The Limiting ply within each plate element around the cutout was determined based on the Tsai-Hill failure criterion. Finite element plates with values below the product of the average Tsai-Hill number and a rejection criterion were subsequently removed. This process was iterated until a steady state was reached and the rejection criterion was then incremented by an evolutionary rate and the above steps repeated until the desired cutout area was achieved. Various plates with differing lay-up and loading parameters were investigated to demonstrate the generality and robustness of this optimization procedure.
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Non-linearities in the electronic stopping power of light projectiles in bulk Al and LiF are addressed from first principles using time-evolving time-dependent density functional theory. In the case of Al, the agreement of the calculations with experiments for H and He projectiles is fair, but a recently observed transition for He from one value of the electronic friction coefficient to a higher value at v ~ 0.3 a.u. is not reproduced by the calculations. For LiF, better accuracy is obtained as compared with previously published simulations, albeit the threshold remains overestimated. © 2013 Elsevier B.V.
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This paper examines the potential of international actors to contribute to conflict resolution by analysing the evolving role of the European Union (EU) in embedding Northern Ireland's peace process. Scrutiny of the EU's approach to conflict resolution in Northern Ireland offers useful insights into the scope and potential of soft power for facilitating behavioural change from governmental to grass-roots levels. This paper traces the development of the EU's approach to conflict resolution in Northern Ireland from one concentrated on encouraging state-level agreement, to nurturing peace through multilevel funding, through now to consolidating the peace by facilitating regional-level empowerment. The core argument is that, in sum, the most critical element of the EU's contribution to peace in Northern Ireland has been, quite simply, that of enduring commitment.
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'Not belonging' is becoming a prevalent theme within accounts of the first-year student experience at university. In this study the notion of not belonging is extended by assuming a more active role for the idea of liminality in a student's transition into the university environments of academic and student life. In doing so, the article suggests that the transition between one place (home) and another (university) can result in an 'in-between-ness' - a betwixt space. Through an interpretative methodology, the study explores how students begin to move from this betwixt space into feeling like fully-fledged members of university life. It is concluded that there is a wide range of turning points associated with the students' betwixt transition, which shapes, alters or indeed accentuates the ways in which they make meaningful connections with university life. Moreover, transitional turning point experiences reveal a cast of characters and symbolic objects; capture contrasting motivations and evolving relationships; display multiple trajectories of interpersonal tensions and conflicts; highlight discontinuities as well as continuities; and together, simultaneously liberate and constrain the students' transition into university life.
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Thermonuclear explosions may arise in binary star systems in which a carbon-oxygen (CO) white dwarf (WD) accretes helium-rich material from a companion star. If the accretion rate allows a sufficiently large mass of helium to accumulate prior to ignition of nuclear burning, the helium surface layer may detonate, giving rise to an astrophysical transient. Detonation of the accreted helium layer generates shock waves that propagate into the underlying CO WD. This might directly ignite a detonation of the CO WD at its surface (an edge-lit secondary detonation) or compress the core of the WD sufficiently to trigger a CO detonation near the centre. If either of these ignition mechanisms works, the two detonations (helium and CO) can then release sufficient energy to completely unbind the WD. These 'double-detonation' scenarios for thermonuclear explosion of WDs have previously been investigated as a potential channel for the production of Type Ia supernovae from WDs of ~ 1 M . Here we extend our 2D studies of the double-detonation model to significantly less massive CO WDs, the explosion of which could produce fainter, more rapidly evolving transients. We investigate the feasibility of triggering a secondary core detonation by shock convergence in low-mass CO WDs and the observable consequences of such a detonation. Our results suggest that core detonation is probable, even for the lowest CO core masses that are likely to be realized in nature. To quantify the observable signatures of core detonation, we compute spectra and light curves for models in which either an edge-lit or compression-triggered CO detonation is assumed to occur. We compare these to synthetic observables for models in which no CO detonation was allowed to occur. If significant shock compression of the CO WD occurs prior to detonation, explosion of the CO WD can produce a sufficiently large mass of radioactive iron-group nuclei to significantly affect the light curves. In particular, this can lead to relatively slow post-maximum decline. If the secondary detonation is edge-lit, however, the CO WD explosion primarily yields intermediate-mass elements that affect the observables more subtly. In this case, near-infrared observations and detailed spectroscopic analysis would be needed to determine whether a core detonation occurred. We comment on the implications of our results for understanding peculiar astrophysical transients including SN 2002bj, SN 2010X and SN 2005E. © 2012 The Authors Monthly Notices of the Royal Astronomical Society © 2012 RAS.
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This article explores the literature concerning responses to pain of both premature and term-born newborn infants, the evidence for short-term and long-term effects of pain, and behavioral sequelae in individuals who have experienced repeated early pain in neonatal life as they mature. There is no doubt that pain causes stress in babies and this in turn may adversely affect long-term neurodevelopmental outcome. Although there are methods for assessing dimensions of acute reactivity to pain in an experimental setting, there are no very good measures available at the present time that can be used clinically. In the clinical setting repeated or chronic pain is more likely the norm rather than infrequent discrete noxious stimuli of the sort that can be readily studied. The wind-up phenomenon suggests that, exposed to a cascade of procedures as happens with clustering of care in the clinical setting in an attempt to provide periods of rest for stressed babies, an infant may in fact perceive procedures that are not normally viewed as noxious, as pain. Pain exposure during lifesaving intensive medical care of ELBW neonates may also affect subsequent reactivity to pain in the neonatal period, but behavioral differences are probably not likely to be clinically significant in the long term. Prolonged and repeated untreated pain in the newborn period, however, may produce a relatively permanent shift in basal autonomic arousal related to prior NICU pain experience, which may have long-term sequelae. In the long run, the most significant clinical effects of early pain exposure may be on neurodevelopment, contributing to later attention, learning, and behavior problems in these vulnerable children. Although there is considerable evidence to support a variety of adverse effects of early pain, there is less information about the long-term effects of opiates and benzodiazepines on the developing central nervous system. Current evidence reviewed suggests that judicious use of morphine for adjustment to mechanical ventilation may ameliorate the altered autonomic response. It may be very important, however, to distinguish stress from pain. Animal evidence suggests that the neonatal brain is affected differently when exposed to morphine administered in the absence of pain than in the presence of pain. Pain control may be important for many reasons but overuse of morphine or benzodiazepines may have undesirable long-term effects. This is a rapidly evolving area of knowledge of clear relevance to clinical management likely to affect long-term outcomes of high-risk children.
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The Irish Pavilion at the Venice Architecture Biennale 2012 charts a position for Irish architecture in a global culture where the modes of production of architecture are radically altered. Ireland is one of the most globalised countries in the world, yet it has developed a national culture of architecture derived from local place as a material construct. We now have to evolve our understanding in the light of the globalised nature of economic processes and architectural production which is largely dependent on internationally networked flows of products, data, and knowledge. We have just begun to represent this situation to ourselves and others. How should a global architecture be grounded culturally and philosophically? How does it position itself outside of shared national reference points?
heneghan peng architects were selected as participants because they are working across three continents on a range of competition-winning projects. Several of these are in sensitive and/or symbolic sites that include three UNESCO World Heritage sites, including the Grand Egyptian Museum in Cairo, the Giants Causeway Visitor Centre in Northern Ireland, and the new Rhine Bridge near Lorelei.
Our dialogue led us to discussing the universal languages of projective geometry and number are been shared by architects and related professionals. In the work of heneghan peng, the specific embodiment of these geometries is carefully calibrated by the choice of materials and the detailed design of their physical performance on site. The stone facade of the Giant’s Causeway Visitor Centre takes precise measure of the properties of the volcanic basalt seams from which it is hewn. The extraction of the stone is the subject of the pavilion wall drawings which record the cutting of stones to create the façade of the causeway centre.
We also identified water as an element which is shared across the different sites. Venice is a perfect place to take measure of this element which suggests links to another site – the Nile Valley which was enriched by the annual flooding of the River Nile. An ancient Egyptian rod for measuring the water level of the Nile inspired the design of the Nilometre - a responsive oscillating bench that invites visitors to balance their respective weights. This action embodies the ways of thinking that are evolving to operate in the globalised world, where the autonomous architectural object is dissolving into an expanded field of conceptual rules and systems. The bench constitutes a shifting ground located in the unstable field of Venice. It is about measurement and calibration of the weight of the body in relation to other bodies; in relation to the site of the installation; and in relation to water. The exhibit is located in the Artiglierie section of the Arsenale. Its level is calibrated against the mark of the acqua alta in the adjacent brickwork of the building which embodies a liminal moment in the fluctuating level of the lagoon.
The weights of bodies, the level of water, changes over time, are constant aspects of design across cultures and collectively they constitute a common ground for architecture - a ground shared with other design professionals. The movement of the bench required complex engineering design and active collaboration between the architects, engineers and fabricators. It is a kind of prototype – a physical object produced from digital data that explores the mathematics at play – the see-saw motion invites the observer to become a participant, to give it a test drive. It shows how a simple principle can generate complex effects that are difficult to predict and invites visitors to experiment and play with them.
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The association between poor metabolic control and the microvascular complications of diabetes is now well established, but the relationship between long-term metabolic control and the accelerated atherosclerosis of diabetes is as yet poorly defined. Hyperglycemia is the standard benchmark by which metabolic control is assessed. One mechanism by which elevated glucose levels may mediate vascular injury is through early and advanced glycation reactions affecting a wide variety of target molecules. The "glycation hypothesis'' has developed over the past 30 years, evolving gradually into a "carbonyl stress hypothesis'' and taking into account not only the modification of proteins by glucose, but also the roles of oxidative stress, a wide range of reactive carbonyl-containing intermediates (derived not only from glucose but also from lipids), and a variety of extra- and intracellular target molecules. The final products of these reactions may now be termed "Either Advanced Glycation or Lipoxidation End-Products'' or "EAGLEs.'' The ubiquity of carbonyl stress within the body, the complexity of the reactions involved, the variety of potential carbonyl intermediates and target molecules and their differing half-lives, and the slow development of the complications of diabetes all pose major challenges in dissecting the significance of these processes. The extent of the reactions tends to correlate with overall metabolic control, creating pitfalls in the interpretation of associative data. Many animal and cell culture studies, while supporting the hypothesis, must be viewed with caution in terms of relevance to human diabetes. In this article, the development of the carbonyl stress hypothesis is reviewed, and implications for present and future treatments to prevent complications are discussed.