Nitrogen geochemistry of a Cretaceous-Tertiary boundary site in New Zealand

Nitrogen in the basal layer of the K-T boundary clay at Woodside Creek, New Zealand, has an abundance of 1100 ppm, a 20-fold enrichment over Cretaceous and Tertiary values. The enrichment parallels that for Ir and elemental carbon (soot); all decrease over the next 6 mm of the boundary clay. The C/N ratio, assuming the nitrogen to be associated with organic rather than elemental carbon, is approximately 5 for the basal layer compared to 20 to 30 for the remainder of the boundary clay. The correlation between N and Ir abundances appears to persist above the boundary, implying that the N is intimately associated with the primary fallout and remained with it during the secondary redeposition processes that kept the Ir abundance relatively high into the lowermost Tertiary. Apparently the basal layer of the boundary clay represents the accumulation of a substantial quantity of N with an isotopic composition approximately 10 percent heavier than background delta value of N-15 values. If the boundary clay represents an altered impact glass from a meteorite impact than it probably denotes a time period of less than 1 year. Therefore, the changes in nitrogen geochemistry apparently occurred over a very short period of time. The high abundance of N and the correspondingly low C/N ratio may reflect enhanced preservation of organic material as a result of the rapid sweepout and burial of plankton by impact ejecta, with little or no bacterial degradation. It is conceivable that the shift in delta value of N-15 may represent an influx of nitrogen from a different source deposited contemporaneously with the impact ejecta. An interesting possibility is that it may be derived from nitrate, produced from the combustion of atmospheric nitrogen

Aspects of habitat selection and the influence of boundaries on some upland invertebrate communities

Aspects of the distribution and ecology of some surface-dwelling invertebrates were examined on different high-altitude vegetation types in the north Pennines, England. The influence of the boundary between habitats on the invertebrate community was also investigated, and the effects of habitat heterogeneity on invertebrate distribution were discussed. Spiders and carabids were sampled from the dominant vegetation types on the plateaux of three mountain summits (Cross Fell, Littie Dun Fell and Great Dun Fell) in 1991 using pitfall traps. Multivariate methods were used to classify and ordinate the sites based on their fauna and to assess the influence of the local environmental variation on the species distribution. Three spider assemblages were recognised based on their common species composition; two short Festuca grassland assemblages and a Nardus/Eriophorum assemblage associated with greater vegetation density. The results suggest that variation in the vegetation structure is the major factor influencing spider distribution on the summit plateaux, with slope and soil depth also contributing. The carabids appeared too widely distributed to assign to any specific vegetation types. The influence of the interface between different vegetation types on the spider and carabid fauna was sampled using pitfall traps in 1992-3. At the boundary between two highly contrasting habitats (sheep pastures and conifer plantations) an edge effect was found in both groups, where species richness was elevated. The major contribution to this increase was the mixing of both pasture and plantation species, species specific to the interface were few. The edge effect at this interface was narrower but larger in spiders than in carabids. At the boundary between two more similar habitats (grazed and ungrazed upland grassland) the edge effect was much reduced, species richness was not elevated, and the level of overlap between habitats was much wider. Edge permeability, structural similarity and altitude were considered the most important factors for the differences between boundaries studied. It is inferred that in the high altitude invertebrate community most species are widespread crossing boundaries between vegetation types regularly, though some species may have affinities to particular habitats for different aspects of their ecology. The implications that this study has for understanding the effects and impacts of habitat heterogeneity at the landscape level are discussed, such as invertebrate movement patterns, population dynamics and management aspects

Evaluating Use of the Doppler Effect to Enhance Auditory Alerts

This is an Accepted Manuscript of an article published by Taylor & Francis in International Journal of Human–Computer Interaction on 10/02/2021, available online: https://doi.org/10.1080/10447318.2020.1870818Auditory alerts are an essential part of many multi-modal interaction scenarios, particularly in safety and mission critical settings, such as hospitals and transportation. A variety of strategies can be employed in the design of auditory alerts, often orienting manipulation of volume and pitch parameters. However, manipulations by applying a Doppler effect are under-investigated. A perceptual listening test is conducted (n = 100) using multiple alert sounds that are subjected to a variety of volume, pitch, and Doppler manipulations, with the unaltered sounds serving as a benchmark. Applying a mixed methods approach consisting of inferential statistics and thematic analysis, it is found that decreases in volume and a Doppler simulation of a sound moving away reduce importance and urgency, increase safety, are harder to detect, and are perceived as being more distant in perceptions of auditory alerts. Further, increases in volume and a Doppler simulation of a sound approaching are effective in communicating safety, whilst pitch manipulations were much less effective. Further work is required to provide wider, ecologically valid, verification of these findings, particularly as to how listener detection of Doppler and volume manipulations can be improved

The application of multivariate cluster analysis in the assessment of volcanic social vulnerability

The 20th Century was characterized by increasing human population settlement in volcanically active regions of the world. This continued growth, particularly in less developed nations, has led to an increasing exposure of households and communities more predisposed to the social and physical risks a disaster could present. This thesis proposes a new methodology for the identification, targeting and assessment of these socially vulnerable communities. Drawing from specific examples of Mount Vesuvius (Italy) and Guagua Pichincha (Ecuador), multivariate statistics are applied to population census data to characterise the frailties and assumed coping capacity of different neighbourhood types to volcanic risk. Using cluster analysis and geodemographic discriminatory techniques, results show that communities more pre-disposed to the social and economic pressures of a disaster can be identified using this method. This approach looks to enhance upon current disaster risk metrics that tend to focus on single or cumulative risk scores, rather than seeking to define the behavioural traits and attitudinal perceptions of a neighbourhood. The peripheral and often informal barrios around Quito, Ecuador are shown to be highly susceptible to volcanic social vulnerability, whilst the Campania province around Vesuvius, Italy, highlights that the greatest risk to community resilience is associated with the high density settlements along the coastal towns near the volcano. The complex nature and site-specific characteristics of volcanic hazards, as well as the cultural landscape in which a volcanic eruption takes place are found to be key determinants in all aspects of disaster reduction. Vulnerability indicators, as defined in previous studies of disaster response are often independent of each other, and in many cases, non-transferrable in different cultural settings. Similarly, vulnerability and risk perception are as much a consequence of culture and state as they are of geographical setting and the physical characteristics of a volcanic eruption. Whilst caution is advised on the application and treatment of vulnerability metrics for mitigation, examples are provided as to how a neighbourhood classification systems methodology can be practically applied for disaster risk reduction. The output of this thesis is proposed as being of direct use to disaster risk managers (DRM), civil authorities and NGOs as an alternative tool in community outreach, exposure management, disaster mitigation and disaster preparedness plans. The contribution is also discussed in the wider context of disaster risk reduction measures, recent conceptual frameworks, and ongoing global initiatives such as the United Nations’ Hyogo Framework for Action and its intended replacement, HFA2

Developing and evaluating the feasibility of an active training game for smart-phones as a tool for promoting executive function in children

Executive function (EF) comprises a series of interrelated cognitive and self-regulatory skills which are required in nearly every facet of everyday life, particularly in novel circumstances. EF skills begin developing from birth and continue to grow well into adulthood but are most crucial for children as they are associated with academic and life success as well as mental and physical health. There is now strong evidence that these skills can be trained through targeted intervention in a diverse range of approaches, such as computer games, physical activity, and social play settings. This thesis presents the process of the design and evaluation of an active EF-training game (BrainQuest) for smart-phones, in participation with end-users: a group of 11-12-year-old children from a local Primary School. The design process placed emphasis on creating an engaging user experience, a phenomenon which has eluded many serious games, by building upon motivational game design theory and satisfying end-user requirements. However, in the pursuit of promoting particular executive functions: working memory; inhibitory control; planning and strategizing, the design integrated aspects of a cognitive assessment while also utilizing a range of alternative approaches for training EF, including physical activity and social play. Following an iterative design process which included many single session prototype evaluations, a mixed methods evaluation was undertaken during a 5-week study with twenty-eight 11-12-year-old school children. The study gathered exploratory qualitative and quantitative evidence regarding the game’s potential benefits which was evaluated by triangulating a range of data sources: multi-observer observations notes, interviews with children and teachers, game performance data and logs, and cognitive assessment outcomes. The analysis describes the statistical relationships between game and executive function ability, before exploring user experiences and evidence of cognitive challenge during gameplay through a series of triangulated case studies and general whole-class observations. The analysis presents the game to be engaging and enjoyable throughout the study and, for most children, able to generate a sustainable challenge. Though there were initial difficulties in understanding the complex game rules and technology, the game became increasingly usable and learnable for the target user group and created opportunities for goal setting. It also encouraged feelings of pride and self-confidence as well as facilitating positive social interactions and requiring regulation of emotion, which are considered to be pathways to developing executive functions (Diamond, 2012). There was also promising initial evidence that the game’s variable difficulty level system was able to challenge executive functions: planning and strategizing, working memory, and inhibitory control. Most notably, the game appeared to support improvements in strategizing ability by demanding increasing strategic complexity in response to evolving and increasingly difficult task demands. Supporting BrainQuest’s cognitive challenge, several statistical relationships emerged between executive function ability and game performance measures. However, the game’s ability to significantly improve cognitive outcomes could not yet be concluded. Nevertheless, these findings have implications for both the future design and evaluation practices undertaken by cognitive training researchers. From a design perspective, less credence should be paid to simply gamifying cognitive assessments while greater emphasis should be placed on integration of formal game design and motivational theories. With regards to evaluation, researchers should understand the importance of establishing first whether CTGs can remain engaging over time as well as the feasibility of their challenge to cognitive functions

A wavelet based approach to the transient control of rotor/active magnetic bearing systems

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Tight intra-operative blood pressure control versus standard care for patients undergoing hip fracture repair - Hip Fracture Intervention Study for Prevention of Hypotension (HIP-HOP) trial: study protocol for a randomised controlled trial

Background: Hypotension during anaesthesia for hip fracture surgery is common. Recent data suggest that there is an association between the lowest intra-operative blood pressure and mortality, even when adjusted for co-morbidities. This is consistent with data derived from the wider surgical population, where magnitude and duration of hypotension are associated with mortality and peri-operative complications. However, there are no trial to data to support more aggressive blood pressure control. Methods/design: We are conducting a three-centre, randomised, double-blinded pilot study in three hospitals in the United Kingdom. The sample size will be 75 patients (25 from each centre). Randomisation will be done using computer-generated concealed tables. Both participants and investigators will be blinded to group allocation. Participants will be aged >70 years, cognitively intact (Abbreviated Mental Test Score 7 or greater), able to give informed consent and admitted directly through the emergency department with a fractured neck of the femur requiring operative repair. Patients randomised to tight blood pressure control or avoidance of intra-operative hypotension will receive active treatment as required to maintain both of the following: systolic arterial blood pressure >80% of baseline pre-operative value and mean arterial pressure >75 mmHg throughout. All participants will receive standard hospital care, including spinal or general anaesthesia, at the discretion of the clinical team. The primary outcome is a composite of the presence or absence of defined cardiovascular, renal and delirium morbidity within 7 days of surgery (myocardial injury, stroke, acute kidney injury, delirium). Secondary endpoints will include the defined individual morbidities, mortality, early mobility and discharge to usual residence. Discussion: This is a small-scale pilot study investigating the feasibility of a trial of tight intra-operative blood pressure control in a frail elderly patient group with known high morbidity and mortality. Positive findings will provide the basis for a larger-scale study