Postglacial vegetation dynamics of western Tierra del Fuego

The southern fringes of the South American landmass provide a rare opportunity to examine the development of moorland vegetation with sparse tree cover in a wet, cool temperate climate of the Southern Hemisphere. We present a record of changes in vegetation over the past 17,000 years, from a lake in extreme southern Chile (Isla Santa Inés, Magallanes region, 53°38.97S; 72°25.24W), where human influence on vegetation is negligible. The western archipelago of Tierra del Fuego remained treeless for most of the Lateglacial period; Lycopodium magellanicum, Gunnera magellanica and heath species dominated the vegetation. Nothofagus may have survived the last glacial maximum at the eastern edge of the Magellan glaciers from where it spread southwestwards and established in the region at around 10,500 cal. yr BP. Nothofagus antarctica was likely the earlier colonizing tree in the western islands, followed shortly after by Nothofagus betuloides. At 9000 cal. yr BP moorland communities expanded at the expense of Nothofagus woodland. Simultaneously, Nothofagus species shifted to dominance of the evergreen Nothofagus betuloides and the Magellanic rain forest established in the region. Rapid and drastic vegetation changes occurred at 5200 cal. yr BP, after the Mt Burney MB2 eruption, including the expansion and establishment of Pilgerodendron uviferum and the development of mixed Nothofagus-Pilgerodendron-Drimys woodland. Scattered populations of Nothofagus, as they occur today in westernmost Tierra del Fuego may be a good analogue for Nothofagus populations during the Lateglacial in eastern sites.

Selective hydrogenation of acetylene in ethylene rich feed streams at high pressure over ligand modified Pd/TiO2

The selective hydrogenation of acetylene from ethylene rich streams was conducted at high pressure and in the presence of CO over two 1 wt% loaded Pd/TiO2 catalysts with differing dispersions. Although, the more poorly dispersed sample did not result in high acetylene conversion only a small proportion of the total available ethylene was hydrogenated to ethane. The more highly dispersed sample was able to remove acetylene to a level below the detection limit but this was at the expense of significant proportion (ca. 30%) of the available ethylene. Modification of the catalysts by exposure to triphenyl phosphine or diphenyl sulfide and subsequent reduction at 393 K led to improved performance with increased conversion of acetylene and decreased propensity to hydrogenate ethylene resulting in an overall net gain in ethylene. The higher dispersed sample which had been ligand modified provided the best results overall and in particular for the diphenyl sulfide treated sample which was able to completely eliminate acetylene and still obtain a net gain in ethylene. The differences observed are thought to be due to the creation of appropriate active ensembles of Pd atoms which are able to accommodate acetylene but have limited ability to adsorb ethylene. Sub-surface hydrogen formation was suppressed, but not eliminated, by exposure to modifier.

Ethno-Religious Segregation in Post-Conflict Belfast

The last 15 years have seen ethno-religious segregation in Belfast stabilize as mixed residential neighbourhoods have expanded on the back of peace and political stability. However, the recession has exposed some of the fragility of these changes and in particular the overreliance on property-led growth and the housing market to achieve lasting forms of desegregation. This paper examines the nature of sociocultural spatial change and in particular how uneven urban restructuring has privileged the south of the city at the expense of the inner east, north and west. The paper concludes by highlighting the implications for housing policy and planning skills both regionally and nationally.

The role of formal structure in liking for popular music

The effect of restructuring the form of three unfamiliar pop/rock songs was investigated in two experiments. In the first experiment, listeners' judgements of the likely location of sections of novel popular songs were explored by requiring participants to place the eight sections (Intro - Verse 1 - Chorus 1 - Verse 2 - Chorus 2 - Bridge (solo) - Chorus 3 - Extro) of the songs into the locations they thought them most likely to occur within the song. Results revealed that participants were able to place the sections in approximately the right location with some accuracy, though they were unable to differentiate between choruses. In Experiment 2, three versions of each of the songs were presented in three different structures: intact (original form), medium restructured (the sections in a moderately changed order), and highly restructured (more severe restructuring). The results show that listeners' judgments of predictability and liking were largely uninfluenced by the restructuring of the songs, in line with findings for classical music. Moment-by-moment liking judgements of the songs demonstrated a change in liking judgements with repeated exposure, though the trend was downwards with repeated exposure rather than upwards. Detailed analysis of moment-by-moment judgements at the ends and beginnings of sections showed that listeners were able to respond quickly to intact songs, but not to restructured songs. The results suggest that concatenism prevails in listening to popular song at the expense of paying attention to larger structural features. © 2012 by the regents of the university of california all rights reserved.

Efficient modelling and optimisation of hybrid multilayered plates subject to ballistic impact

Among the key challenges present in the modelling and optimisation of composite structures against impact is the computational expense involved in setting up accurate simulations of the impact event and then performing the iterations required to optimise the designs. It is of more interest to find good designs given the limitations of the resources and time available rather than the best possible design. In this paper, low cost but sufficiently accurate finite element (FE) models were generated in LS Dyna for several experimentally characterised materials by semi-automating the modelling process and using existing material models. These models were then used by an optimisation algorithm to generate new hybrid offspring, leading to minimum weight and/or cost designs from a selection of isotropic metals, polymers and orthotropic fibre-reinforced laminates that countered a specified impact threat. Experimental validation of the optimal designs thus identified was then successfully carried out using a single stage gas gun. With sufficient computational hardware, the techniques developed in this pilot study can further utilise fine meshes, equations of state and sophisticated material models, so that optimal hybrid systems can be identified from a wide range of materials, designs and threats.

Sub-luminous type Ia supernovae from the mergers of equal-mass white dwarfs with mass 0.9M

Type Ia supernovae are thought to result from thermonuclear explosions of carbong'oxygen white dwarf stars. Existing models generally explain the observed properties, with the exception of the sub-luminous 1991bg-like supernovae. It has long been suspected that the merger of two white dwarfs could give rise to a type Ia event, but hitherto simulations have failed to produce an explosion. Here we report a simulation of the merger of two equal-mass white dwarfs that leads to a sub-luminous explosion, although at the expense of requiring a single common-envelope phase, and component masses of 0.9M. The light curve is too broad, but the synthesized spectra, red colour and low expansion velocities are all close to what is observed for sub-luminous 1991bg-like events. Although the mass ratios can be slightly less than one and still produce a sub-luminous event, the masses have to be in the range 0.83M to 0.9M. © 2010 Macmillan Publishers Limited. All rights reserved.

A Case for Humanity in the Law of Rape.

One of Irigaray’s most insistent criticisms of the operation of patriarchal law is its overwhelming focus on the protection of property at the expense of law that regulates relations between and amongst persons. This paper argues, with reference to Irigaray’s work, that the conceptual change involved in such a reorientation of law’s focus has important implications for the legal perception of the harm of rape and woman’s sexuality. The possessive paradigm operates in the law of rape by disassociating the harm of rape from its psychic and subjective impact and encouraging the ‘simple’rape/ ‘real’ rape dichotomy. In returning subjectivity to woman herself we can begin to see perhaps how the crime of rape involves a harm to woman that affects the whole of her being, and to be. Such a reading allows the law to perhaps move away from understanding rape as a violation of undifferentiated bodies to a violation of the innate ‘virginity’ of woman.

Total Addiction:The Life of an Eclipse Chaser

Seeing a total solar eclipse is often described as a once-in-a-lifetime experience. However, for many who have experienced totality, once-in-a-lifetime is simply not enough. They want more, and are willing to go to great lengths often at great expense to repeat the experience. What is it like to experience totality? What is it about the experience that motivates these eclipse chasers? Is there an eclipse chaser personality? Can eclipse chasing actually be described as an addiction? This book describes the people who dedicate their lives to chasing their dream.

The effects of new topical treatments on management of glaucoma in Scotland:An examination of ophthalmological health care

Background: The management of glaucoma has been changed in the past decade by the introduction of new drugs. The impact of these changes on clinical care of patients was examined by examining operation and prescribing rates for glaucoma in four geographical areas of Scotland for the years 1994 to 1999. Methods: A retrospective analysis of national health statistics: primary care prescribing data, hospital derived operation rates, consultant numbers, optometrist numbers, and eye test data, expressed by estimated population at risk of glaucoma. The outcome measures were prescribing volume and cost for glaucoma medications, and operation rates, corrected for population estimated to be at risk of glaucoma (PEG), for trabeculectomy, for Scotland as a whole, and for four geographical "regions" (north east, south east, central, and south west Scotland). Results: Prescribed items per 1000 population estimated to have glaucoma (PEG) increased by 24.9% between 1994 and 1999. This was above the general increase in prescribing in Scotland (17.8%). This increase varied in the four health regions evaluated (14.3% to 31.9%). Prescribing of topical ß blockers increased little (6.4%), but there was a large increase in the use of new products (topical prostaglandins, carbonic anhydrase inhibitors, and a agonists), at the expense of miotics (47.7% fall), and older sympathomimetics. This change in prescribing pattern was accompanied by a 61.5% increase in cost (range 42.2% to 73.4% in the four regions). New drugs accounted for more than half of total glaucoma expenditure in 1999. Operation rates (corrected for PEG) fell by 45.9% (range 43.1 to 58.6%) between 1994 and 1999. Other indicators suggested increased activity in ophthalmic areas (for example, cataract operations, eye tests, numbers of optometrists and ophthalmic surgeons all increased). Within north east Scotland operation rates decreased and prescribing increased less than in other regions, both from lowest regional baseline in 1994. Conclusions: The introduction of new drug classes has had dramatic effects on the prescribing of glaucoma treatments. There has been a decline in older treatments and an increase in new agents, which has been associated with a large reduction in operation rates for glaucoma in Scotland over 6 years. Comparison of prescribing and operation data indicates regional differences in healthcare delivery for glaucoma.

Ethylene oxidation over platinum: In situ electrochemically controlled promotion using Na-beta'' alumina and studies with a Pt(111)/Na model catalyst

Electrochemically modified ethylene oxidation over a PI film supported on the Na+ ion conductor beta '' alumina has been studied over a range of conditions encompassing both promotion and poisoning, The system exhibits reversible behavior, and the data are interpreted in terms of (i) Na-enhanced oxygen chemisorption and (ii) poisoning of the surface by accumulation of Na compounds. At low Na coverages the first effect results in increased competitive adsorption of oxygen at the expense of ethylene, resulting in an increased rate, At very negative catalyst potentials (high Na coverage) both effects operate to poison the system: the increased strength of the Pt-O bond and coverage of the catalytic surface by compounds of Na strongly suppress the rate, Kinetic and spectroscopic results for ethylene oxidation over a Pt(111)-Na model catalyst shed light on important aspects of the electrochemically controlled system, Low levels of Na promote the reaction and high levels poison it, mirroring the behavior observed under electrochemical control and strongly suggesting that sodium pumped from the solid electrolyte is the key species, XP and Auger spectra show that under reaction conditions, the sodium exists as a surface carbonate. Post-reaction TPD spectra and the use of (CO)-C-13 demonstrate that CO is formed as a stable reaction intermediate, The observed activation energy (56 +/- 3 kJ/mol) is similar to that measured for CO oxidation under comparable conditions, suggesting that the rate limiting step is CO oxidation. (C) 1996 Academic Press, Inc.

A low-cost solution for the restoration of femoral head centre during total hip arthroplasty

Restoration of joint centre during total hip arthroplasty is critical. While computer-aided navigation can improve accuracy during total hip arthroplasty, its expense makes it inaccessible to the majority of surgeons. This article evaluates the use, in the laboratory, of a calliper with a simple computer application to measure changes in femoral head centres during total hip arthroplasty. The computer application was designed using Microsoft Excel and used calliper measurements taken pre- and post-femoral head resection to predict the change in head centre in terms of offset and vertical height between the femoral head and newly inserted prosthesis. Its accuracy was assessed using a coordinate measuring machine to compare changes in preoperative and post-operative head centre when simulating stem insertion on 10 sawbone femurs. A femoral stem with a modular neck was used, which meant nine possible head centre configurations were available for each femur, giving 90 results. The results show that using this technique during a simulated total hip arthroplasty, it was possible to restore femoral head centre to within 6?mm for offset (mean 1.67?±?1.16?mm) and vertical height (mean 2.14?±?1.51?mm). It is intended that this low-cost technique be extended to inform the surgeon of a best-fit solution in terms of neck length and neck type for a specific prosthesis.

Effectiveness of the Construction Management Courses

This research assesses the effectiveness of current MSc. Construction Project Management programmes within the UK and Ireland. A review of published prospectuses is used to create questionnaires for universities, graduates and employers. Responses provide an insight into programme creation and their relative success in addressing the needs of industry and in achieving other educational objectives. Since the majority of learning institutions have attained professional accreditation, it is useful to review these awards and to assess their potential value to both graduates and industry alike. Interviews are conducted with representatives from the main professional accrediting bodies to understand their procedures and rigour in enforcing standards of education and training. The results show that project management education could be further enhanced by the inclusion of more practical learning and that current programmes place greater emphasis on hard skills at the expense of the softer human skills. There is clearly a need for a closer working relationship between academics and practitioners to tackle the perceived gap between theoretical learning and construction practice. Learning institutions can use the findings to improve their programmes and address the education deficiencies identified by the industry, by the professional institutions and by graduates.

Queer Spaces, Sexual Violence and the Desire for Safety

Queer politics and spaces have historically been associated with ideals of sexual liberation. They are conceptualised as spaces where sex, and its intersections with intimacy, friendship and love can be explored outside of normative frameworks which value monogamous reproductive heterosexuality at the expense of other non-normative sexual expressions. In recent years, however, autonomous queer spaces such as the global Queeruption gatherings and other queer community spaces in Australia have become increasingly concerned with the presence and danger of sexual violence in queer communities. Almost without exception, this danger has been responded to through the creation of ‘safe(r) spaces’ policies, generally consisting of a set of guidelines and proscribed behaviours which individuals must agree to in order to participate in or attend the event or space. The guidelines themselves tend to privilege of sexual politics of affirmative verbal consent, insisting that such consent should be sought prior to any physical or sexual contact, inferring that a failure to do so is ethically unacceptable within. This chapter reflects on the attempts to construct queer communities as ‘safer spaces,’ arguing that the concepts of consent and safety are inadequate to develop a queer response to sexual violence. Such a response, it argues, must be based on the openness to possibilities and refusal of sexual restrictions and regulations that have always been central elements of queer theory and politics.

Advantages and limitations of navigation-based multicriteria optimization (MCO) for localized prostate cancer IMRT planning

Efficacy of inverse planning is becoming increasingly important for advanced radiotherapy techniques. This study's aims were to validate multicriteria optimization (MCO) in RayStation (v2.4, RaySearch Laboratories, Sweden) against standard intensity-modulated radiation therapy (IMRT) optimization in Oncentra (v4.1, Nucletron BV, the Netherlands) and characterize dose differences due to conversion of navigated MCO plans into deliverable multileaf collimator apertures. Step-and-shoot IMRT plans were created for 10 patients with localized prostate cancer using both standard optimization and MCO. Acceptable standard IMRT plans with minimal average rectal dose were chosen for comparison with deliverable MCO plans. The trade-off was, for the MCO plans, managed through a user interface that permits continuous navigation between fluence-based plans. Navigated MCO plans were made deliverable at incremental steps along a trajectory between maximal target homogeneity and maximal rectal sparing. Dosimetric differences between navigated and deliverable MCO plans were also quantified. MCO plans, chosen as acceptable under navigated and deliverable conditions resulted in similar rectal sparing compared with standard optimization (33.7 ± 1.8Gy vs 35.5 ± 4.2Gy, p = 0.117). The dose differences between navigated and deliverable MCO plans increased as higher priority was placed on rectal avoidance. If the best possible deliverable MCO was chosen, a significant reduction in rectal dose was observed in comparison with standard optimization (30.6 ± 1.4Gy vs 35.5 ± 4.2Gy, p = 0.047). Improvements were, however, to some extent, at the expense of less conformal dose distributions, which resulted in significantly higher doses to the bladder for 2 of the 3 tolerance levels. In conclusion, similar IMRT plans can be created for patients with prostate cancer using MCO compared with standard optimization. Limitations exist within MCO regarding conversion of navigated plans to deliverable apertures, particularly for plans that emphasize avoidance of critical structures. Minimizing these differences would result in better quality treatments for patients with prostate cancer who were treated with radiotherapy using MCO plans.

Pre-charging and DC Fault Ride-Through of Hybri MMC Based HVDC Systems

Compared to half-bridge based MMCs, full-bridge based systems have the advantage of blocking dc fault, but at the expense of increased power semiconductors and power losses. In view of the relationships among ac/dc voltages and currents in full-bridge based MMC with the negative voltage state, this paper provides a detailed analysis on the link between capacitor voltage variation and the maximum modulation index. A hybrid MMC, consisting of mixed half-bridge and full-bridge circuits to combine their respective advantages is investigated in terms of its pre-charging process and transient dc fault ride-through capability. Simulation and experiment results demonstrate the feasibility and validity of the proposed strategy for a full-bridge based MMC and the hybrid MMC.