Calling for help : a responsive evaluation of Child Health Line

The project examined the responsiveness of the telenursing service provided by the Child Health Line (hereinafter referred to as CHL). It aimed to provide an account of population usage of the service, the call request types and the response of the service to the calls. In so doing, the project extends the current body of knowledge pertaining to the provision of parenting support through telenursing. Approximately 900 calls to the CHL were audio-recorded over the December 2005-2006 Christmas-New Year period. A protocol was developed to code characteristics of the call, the interactional features between the caller and nurse call-taker, and the extent to which there was (a) agreement on problem definition and the plan of action and (b) interactional alignment between nurse and caller. A quantitative analysis examined the frequencies of the main topics covered in calls to the CHL and any statistical associations between types of calls, length of calls and nurse-caller alignment. In addition, a detailed qualitative analysis was conducted on a subset of calls dealing with the nurse management of calls seeking medical advice and information. Key findings include: • Overall, 74% of the calls discussed parenting and child development issues, 48% discussed health/medical issues, and 16% were information-seeking calls. • More specifically: o 21% discussed health/medical and parenting and child development issues. o 3% discussed parenting and information-seeking issues. o 5% discussed health/medical, parenting/development and information issues. o 18% exclusively focussed on health and medical issues and therefore were outside the remit of the intended scope of the CHL. These calls caused interactional dilemmas for the nurse call-takers as they simultaneously dealt with parental expectations for help and the CHL guidelines indicating that offering medical advice was outside the remit of the service. • Most frequent reasons for calling were to discuss sleep, feeding, normative infant physical functions and parenting advice. • The average length of calls to the CHL was 7 minutes. • Longer calls were more likely to involve nurse call-takers giving advice on more than one topic, the caller displaying strong emotions, the caller not specifically providing the reason for the call, and the caller discussing parenting and developmental issues. • Shorter calls were characterised by the nurse suggesting that the child receive immediate medical attention, the nurse emphasising the importance or urgency of the plan of action, the caller referring to or requesting confirmation of a diagnosis, and caller and nurse call-taker discussion of health and medical issues. • The majority of calls, 92%, achieved parent-nurse alignment by the conclusion of the call. However, 8% did not. • The 8% of calls that were not aligned require further quantitative and qualitative investigation of the interactional features. The findings are pertinent in the current context where Child Health Line now resides within 13HEALTH. These findings indicate: 1. A high demand for parenting advice. 2. Nurse call-takers have a high level of competency in dealing with calls about parenting and normal child development, which is the remit of the CHL. 3. Nurse call-takers and callers achieve a high degree of alignment when both parties agree on a course of action. 4. There is scope for developing professional practice in calls that present difficulties in terms of call content, interactional behaviour and call closure. Recommendations of the project: 1. There are numerous opportunities for further research on interactional aspects of calls to the CHL, such as further investigations of the interactional features and the association of the features to alignment and nonalignment. The rich and detailed insights into the patterns of nurse-parent interactions were afforded by the audio-recording and analysis of calls to the CHL. 2. The regular recording of calls would serve as a way of increasing understanding of the type and nature of calls received, and provide a valuable training resource. Recording and analysing calls to CHL provides insight into the operation of the service, including evidence about the effectiveness of triaging calls. 3. Training in both recognising and dealing with problem calls may be beneficial. For example, calls where the caller showed strong emotion, appeared stressed, frustrated or troubled were less likely to be rated as aligned calls. In calls where the callers described being ‘at their wits end’, or responded to each proposed suggestion with ‘I’ve tried that’, the callers were fairly resistant to advice-giving. 4. Training could focus on strategies for managing calls relating to parenting support and advice, and parental well-being. The project found that these calls were more likely to be rated as being nonaligned. 5. With the implementation of 13HEALTH, future research could compare nurse-parent interaction following the implementation of triaging. Of the calls, 21% had both medical and parenting topics discussed and 5.3% discussed medical, parenting and information topics. Added to this, in 12% of calls, there was ambiguity between the caller and nurse call-taker as to whether the problem was medical or behavioural.

Developing and benchmarking native Linux applications on Android

Smartphones get increasingly popular where more and more smartphone platforms emerge. Special attention was gained by the open source platform Android which was presented by the Open Handset Alliance (OHA) hosting members like Google, Motorola, and HTC. Android uses a Linux kernel and a stripped-down userland with a custom Java VM set on top. The resulting system joins the advantages of both environments, while third-parties are intended to develop only Java applications at the moment. In this work, we present the benefit of using native applications in Android. Android includes a fully functional Linux, and using it for heavy computational tasks when developing applications can bring in substantional performance increase. We present how to develop native applications and software components, as well as how to let Linux applications and components communicate with Java programs. Additionally, we present performance measurements of native and Java applications executing identical tasks. The results show that native C applications can be up to 30 times as fast as an identical algorithm running in Dalvik VM. Java applications can become a speed-up of up to 10 times if utilizing JNI.

Naming or creating a problem?

In this chapter, we are going to consider how language and practice interact in the process of supporting the learning of students with diverse abilities. You will learn that it is necessary for teachers to understand that while labels carry an administrative function in schools, when used carelessly they operate to stigmatise and exclude those whom we are working to include. This chapter will introduce the concept of equity and explain how the dilemma of difference emerges when we try to determine who should receive support and how. The chapter will also explain how an appreciation of language can help to inform and transform our pedagogy. An example of inclusion in action is provided to illustrate how inclusive language in practice can promote deep cultural changes that benefit both students and teachers. The process of determining appropriate and effective education of students with additional support requirements is troubled by what some refer to as the ‘dilemma of difference’. This dilemma derives mainly from the nature of language and our need to use certain words, terms and categories in order to share common understandings. Without these, educators cannot hope to arrive on the same page, yet such words can take on a life of their own; influencing thoughts, perspectives and attitudes in ways that far outstrip original intentions. The drive for clarity, however, through definition and diagnostic classification can ultimately obscure because of the cultural meanings that become invested within these terms through their use over time and in different professional contexts. In effect, trying to define “difference” in order to provide the right support to particular students is a process that entrenches normative boundaries that in turn create, accentuate and stigmatise whatever we have decided constitutes difference. Language is thus a powerful and dangerous weapon but, like other weapons, language can both hurt and defend. Understanding the power of language enables educators to use it both wisely and safely to the maximum benefit of their students. This chapter will discuss how teachers can recognise and support their students in ways that avoid stigma and the closure of stereotyping.

Experimental and modelling investigation of monolayer development with clustering

Standard differential equation–based models of collective cell behaviour, such as the logistic growth model, invoke a mean–field assumption which is equivalent to assuming that individuals within the population interact with each other in proportion to the average population density. Implementing such assumptions implies that the dynamics of the system are unaffected by spatial structure, such as the formation of patches or clusters within the population. Recent theoretical developments have introduced a class of models, known as moment dynamics models, which aim to account for the dynamics of individuals, pairs of individuals, triplets of individuals and so on. Such models enable us to describe the dynamics of populations with clustering, however, little progress has been made with regard to applying moment dynamics models to experimental data. Here, we report new experimental results describing the formation of a monolayer of cells using two different cell types: 3T3 fibroblast cells and MDA MB 231 breast cancer cells. Our analysis indicates that the 3T3 fibroblast cells are relatively motile and we observe that the 3T3 fibroblast monolayer forms without clustering. Alternatively, the MDA MB 231 cells are less motile and we observe that the MDA MB 231 monolayer formation is associated with significant clustering. We calibrate a moment dynamics model and a standard mean–field model to both data sets. Our results indicate that the mean–field and moment dynamics models provide similar descriptions of the 3T3 fibroblast monolayer formation whereas these two models give very different predictions for the MDA MD 231 monolayer formation. These outcomes indicate that standard mean–field models of collective cell behaviour are not always appropriate and that care ought to be exercised when implementing such a model.

Kinetic energy of He atoms in liquid He-4-He-3 mixtures

Deep inelastic neutron scattering measurements on liquid 3He-4He mixtures in the normal phase have been performed on the VESUVIO spectrometer at the ISIS pulsed neutron source at exchanged wave vectors of about q≃120.0Å-1. The neutron Compton profiles J(y) of the mixtures were measured along the T=1.96K isotherm for 3He concentrations, x, ranging from 0.1 to 1.0 at saturated vapor pressures. Values of kinetic energies 〈T〉 of 3He and 4He atoms as a function of x, 〈T〉(x), were extracted from the second moment of J(y). The present determinations of 〈T〉(x) confirm previous experimental findings for both isotopes and, in the case of 3He, a substantial disagreement with theory is found. In particular 〈T〉(x) for the 3He atoms is found to be independent of concentration yielding a value 〈T〉3(x=0.1)≃12K, much lower than the value suggested by the most recent theoretical estimates of approximately 19 K.

A Summative Evaluation of the Stronger Smarter Learning Communities Project : Vol 1 and Vol 2

This is a summative evaluation of the Stronger Smarter Learning Communities (SSLC) project that examines whether and how the SSLC project had an impact on Australian state schools which adopted its models and approaches. Drawing from qualitative and quantitative data sets, it also presents the largest scale and most comprehensive analysis of Indigenous education practices and outcomes to date. It includes empirical findings on: success in changing school ethos and community engagement; challenges in progress at closure of the 'gap' in conventionally measured achievement and performance; schools' and principals' choices in curriculum and instruction; profiles of teachers' and principals' training and views on teacher education; and a strong emphasis on community and school Indigenoous voices and views on Indigenous education.

Design of LSF wall studs under fire conditions

Cold-formed steel lipped channels are commonly used in LSF wall construction as load bearing studs with plasterboards on both sides. Under fire conditions, cold-formed thin-walled steel sections heat up quickly resulting in fast reduction in their strength and stiffness. Usually the LSF wall panels are subjected to fire from one side which will cause thermal bowing, neutral axis shift and magnification effects due to the development of non-uniform temperature distributions across the stud. This will induce an additional bending moment in the stud and hence the studs in LSF wall panels should be designed as a beam column considering both the applied axial compression load and the additional bending moment. Traditionally the fire resistance rating of these wall panels is based on approximate prescriptive methods. Very often they are limited to standard wall configurations used by the industry. Therefore a detailed research study is needed to develop fire design rules to predict the failure load and hence the failure time of LSF wall panels subject to non-uniform temperature distributions. This paper presents the details of an investigation to develop suitable fire design rules for LSF wall studs under non-uniform elevated temperature distributions. Applications of the previously developed fire design rules based on AISI design manual and Eurocode 3 Parts 1.2 and 1.3 to LSF wall studs were investigated in detail and new simplified fire design rules based on AS/NZS 4600 and Eurocode 3 Part 1.3 were proposed in the current study with suitable allowances for the interaction effects of compression and bending actions. The accuracy of the proposed fire design rules was verified by using the results from full scale fire tests and extensive numerical studies.

The effect of testing protocol on immature bovine thoracic spine segment stiffness

Introduction. In vitro spine biomechanical testing has been central to many advances in understanding the physiology and pathology of the human spine. Owing to the difficulty in obtaining sufficient numbers of human samples to conduct these studies, animal spines have been accepted as a substitute model. However, it is difficult to compare results from different studies, as they use different preparation, testing and data collection methods. The aim of this study was to identify the effect of repeated cyclic loading on bovine spine segment stiffness. It also aimed to quantify the effect of multiple freeze-thaw sequences, as many tests would be difficult to complete in a single session [1-3]. Materials and Methods. Thoracic spines from 6-8 week old calves were used. Each spine was dissected and divided into motion segments including levels T4-T11 (n=28). These were divided into two equal groups. Each segment was potted in polymethylemethacrylate. An Instron Biaxial materials testing machine with a custom made jig was used for testing. The segments were tested in flexion/extension, lateral bending and axial rotation at 37 degrees C and 100% humidity, using moment control to a maximum plus/minus 1.75 Nm with a loading rate of 0.3 Nm per second. Group (A) were tested with continuous repeated cyclic loading for 500 cycles with data recorded at cycles 3, 5, 10, 25, 100, 200, 300, 400 and 500. Group (B) were tested with 10 load cycles after each of 5 freeze thaw sequences. Data was collected from the tenth load cycle after each sequence. Statistical analysis of the data was performed using paired samples t-tests, ANOVA and generalized estimating equations. Results. The data were confirmed as having a normal distribution. 1. There were significant reductions in mean stiffness in flexion/extension (-20%; P=0.001) and lateral bending (-17%; P=0.009) over the 500 load cycles. However, there was no statistically significant change in axial rotation (P=0.152) 2. There was no statistically significant difference between mean stiffness over the five freeze-thaw sequences in flexion/extension (p=0.879) and axial rotation (p=0.07). However, there was a significant reduction in stiffness in lateral bending (-26%; p=0.007) Conclusion. Biomechanical testing of immature bovine spine motion segments requires careful interpretation. The effect of the number of load cycles as well as the number of freeze-thaw cycles on the stiffness of the motion segments depends on the axis of main movement.

Half metallicity in a zigzag double-walled nanotube nanodot : an Ab initio prediction

Ab initio density functional calculations were performed to study finite-length zigzag (7, 0) @ (16, 0) double-walled carbon nanotubes (DWCNTs) with H-termination at the open ends. We find that such a DWCNT nanodot displays a very large magnetic moment at the zigzag edges and the ground state displays symmetric anti-ferromagnetic coupling. When an external electric field is applied along the direction of tube axis, a gap is opened for one spin channel, whereas another spin channel remains metallic, i.e. half metallicity occurs. Our results suggest an important new avenue for the development of CNT-based spintronic materials with enhanced properties.

Vision-only autonomous navigation using topometric maps

This paper presents a mapping and navigation system for a mobile robot, which uses vision as its sole sensor modality. The system enables the robot to navigate autonomously, plan paths and avoid obstacles using a vision based topometric map of its environment. The map consists of a globally-consistent pose-graph with a local 3D point cloud attached to each of its nodes. These point clouds are used for direction independent loop closure and to dynamically generate 2D metric maps for locally optimal path planning. Using this locally semi-continuous metric space, the robot performs shortest path planning instead of following the nodes of the graph --- as is done with most other vision-only navigation approaches. The system exploits the local accuracy of visual odometry in creating local metric maps, and uses pose graph SLAM, visual appearance-based place recognition and point clouds registration to create the topometric map. The ability of the framework to sustain vision-only navigation is validated experimentally, and the system is provided as open-source software.

Spin-polarization and ferromagnetism of graphitic carbon nitride materials

Polymeric graphitic carbon nitride materials have attracted increasing attention in recent years owning to their potential applications in energy conversion, environment protection, and so on. Here, from first-principles calculations, we report the electronic structure modification of graphitic carbon nitride (g-C3N4) in response to carbon doping. We showed that each dopant atom can induce a local magnetic moment of 1.0 μB in non-magnetic g-C3N4. At the doping concentration of 1/14, the local magnetic moments of the most stable doping configuration which has the dopant atom at the center of heptazine unit prefer to align in a parallel way leading to long-range ferromagnetic (FM) ordering. When the joint N atom is replaced by C atom, the system favors an antiferromagnetic (AFM) ordering at unstrained state, but can be tuned to ferromagnetism (FM) by applying biaxial tensile strain. More interestingly, the FM state of the strained system is half-metallic with abundant states at the Fermi level in one spin channel and a band gap of 1.82 eV in another spin channel. The Curie temperature (Tc) was also evaluated using a mean-field theory and Monte Carlo simulations within the Ising model. Such tunable electron spin-polarization and ferromagnetism are quite promising for the applications of graphitic carbon nitride in spintronics.

Producing and maintaining professional identities in early childhood

This study is an inquiry into early childhood teacher professional identities. In Australia, workforce reforms in early childhood include major shifts in qualification requirements that call for a university four-year degree-qualified teacher to be employed in child care. This marks a shift in the early years workforce, where previously there was no such requirement. At the same time as these reforms to quality measures are being implemented, and requiring a substantive up skilling of the workforce, there is a growing body of evidence through recent studies that suggests these same four-year degree-qualified early childhood teachers have an aversion to working in child care. Their preferred employment option is to work in the early years of more formal schooling, not in before-school contexts. This collision of agendas warrants investigation. This inquiry is designed to investigate the site at which advocacy for higher qualification requirements meets early childhood teachers who are reluctant to choose child care as a possible career pathway. The key research question for this study is: How are early childhood teachers’ professional identities currently produced? The work of this thesis is to problematise the early childhood teacher in child care through a particular method of discourse analysis. There are two sets of data. The first was a key early childhood political document that read as a "moment of arising" (Foucault, 1984a, p. 83). It is a political document which was selected for its current influence on the early childhood field, and in particular, workforce reforms that call for four-year degree-qualified teachers to work in before-school contexts, including child care. The second data set was generated through four focus group discussions conducted with preservice early childhood teachers. The document and transcripts of the focus groups were both analysed as text, as conceptualised by Foucault (1981). Foucault’s work spans a number of years and a range of philosophical matters. This thesis draws particularly on Foucault’s writings on discourse, power/knowledge, regimes of truth and resistance. In order to consider the production of early childhood teachers’ professional identities, the study is also informed by identity theorists, who have worked on gender, performativity and investment (Davies, 2004/2006; McNay, 1992; Osgood, 2012; Walkerdine, 1990; Weedon, 1997). The ways in which discourses intersect, compete and collide produce the subject (Foucault, 1981) and, in the case of this inquiry, there are a number of competing discourses at play, which produce the early childhood teacher. These particular theories turn particular lenses on the question of professional identities in early childhood, and such a study calls for the application of particular methodologies. Discourse analysis was used as the methodological framework, and the analysis was informed by Foucauldian concepts of discourse. While Foucault did not prescribe a form of discourse analysis as a method, his writings nonetheless provide a valuable framework for illuminating discursive practices and, in turn, how people are affected, through the shifts and distribution of power (Foucault, 1980a). The treatment used with both data sets involved redescription. For the policy document, a technique for reading document-as-text applied a genealogical approach (Foucault, 1984a). For the focus groups, the process of redescription (Rorty, 1989) involved reading talk-as-text. As a method, redescription involves describing "lots and lots of things in new ways until you have created a pattern of linguistic behaviour which will tempt the new generation to adopt it" (Rorty, 1989, p. 9). The development and application of categories (Davies, 2004/2006) built on a poststructuralist theoretical framework and the literature review informed the data analysis method of discourse analysis. Irony provided a rhetorical and playful tool (Haraway, 1991; Rorty, 1989), to look to how seemingly opposing discourses are held together. This opens a space to collapse binary thinking and consider seemingly contradictory terms in a way in which both terms are possible and both are true. Irony resists the choice of one or the other being right, and holds the opposites together in tension. The thesis concludes with proposals for new, ironic categories, which work to bring together seemingly opposing terms, located at sites in the field of early childhood where discourses compete, collide and intersect to produce and maintain early childhood teacher professional identities. The process of mapping these discourses goes some way to investigating the complexities about identities and career choices of early childhood teachers. The category of "the cost of loving" captures the collision between care/love, inherent in child care, and new discourses of investment/economics. Investment/economics has not completely replaced care/love, and these apparent opposites were not read as a binary because both are necessary and both are true (Haraway, 1991). They are held together in tension to produce early childhood teacher professional identities. The policy document under scrutiny was New Directions, released in 2007 by the then opposition ALP leader, Kevin Rudd. The claim was made strongly that the "economic prosperity" of Australia relies on investment in early childhood. The arguments to invest are compelling and the neuroscience/brain research/child development together with economic/investment discourses demand that early childhood is funding is increased. The intersection of these discourses produces professional identities of early childhood teachers as a necessary part of the country’s economy, and thus, worthy of high status. The child care sector and work in child care settings are necessary, with children and the early childhood teacher playing key roles in the economy of the nation. Through New Directions it becomes sayable (Foucault, 1972/1989) that the work the early childhood teacher performs is legitimated and valued. The children are produced as "economic units". A focus on what children are able to contribute to the future economy of the nation re-positions children and produces these "smart productive citizens", making future economic contribution. The early childhood teacher is produced through this image of a child and "the cost of loving" is emphasised. A number of these categories were produced through the readings of the document-as text and the talk-as-text. Two ironic categories were read in the analysis of the transcripts of the focus group discussions, when treated as talk-as-text data: the early childhood teacher as a "heroic victim"; and the early childhood teacher as a "glorified babysitter". This thesis raises new questions about professional identities in early childhood. These new questions might go some way to prompt re-thinking of some government policy, as well as some aspects of early childhood teacher education course design. The images of children and images of child care provide provocations to consider preservice teacher education course design. In particular, how child care, as one of the early childhood contexts, is located, conceptualised and spoken throughout the course. Consideration by course designers and teacher educators of what discourses are privileged in course content —what discourses are diminished or silenced—would go some way to reconceptualising child care within preservice teacher education and challenging dominant ways of speaking child care, and work in child care. This inquiry into early childhood teachers’ professional identities has gone some way to exploring the complexities around the early childhood teacher in child care. It is anticipated that the significance of this study will thus have immediate applicably and relevance for the Australian early childhood policy landscape. The early childhood field is in a state of rapid change, and this inquiry has examined some of the disconnects between policy and practice. Awareness of the discourses that are in play in the field will continue to allow space for conversations that challenge dominant assumptions about child care, work in child care and ways of being an early childhood teacher in child care.

Illustrating outcomes for Australian nascent and young firm entrepreneurial activity

This paper examines the outcomes of nascent and young entrepreneurial firms in Australia. Findings of interest in this paper include: • After three years similar proportions of nascent firms reach an operational state (31 per cent), i.e. sales regularly exceed costs, compared with those that have terminated (35 per cent), and those who are still trying to achieve venture creation (34 per cent). This outcome closely mirrors the outcomes in the US PSED study. • The young firm sample shows that these new ventures remain more robust to firm closure. The vast majority of young firms (78 per cent) continue to be active in the market the last time they participated in CAUSEE. • The annual termination rate for young firms is 9 per cent at most, and 14 per cent cumulatively, while cumulatively only 8 per cent of young firms experience a drop-off in activity to be considered as having uncertain status. • The average number of employees in Nascent Firms is one person, the average number of Young Firm employees increases from two at first sampling to three after three years. • While the founders of exiting Nascent Firms are more likely to return to their old job upon termination of their business, Young Firm founders move on to new jobs. Regardless the majority of exiting firm founders rate their experience as positive and are prepared to attempt business creation in the future.

Ultimate flexural limit states analysis of prestressed concrete sleeper

Railway is one of the most important, reliable and widely used means of transportation, carrying freight, passengers, minerals, grains, etc. Thus, research on railway tracks is extremely important for the development of railway engineering and technologies. The safe operation of a railway track is based on the railway track structure that includes rails, fasteners, pads, sleepers, ballast, subballast and formation. Sleepers are very important components of the entire structure and may be made of timber, concrete, steel or synthetic materials. Concrete sleepers were first installed around the middle of last century and currently are installed in great numbers around the world. Consequently, the design of concrete sleepers has a direct impact on the safe operation of railways. The "permissible stress" method is currently most commonly used to design sleepers. However, the permissible stress principle does not consider the ultimate strength of materials, probabilities of actual loads, and the risks associated with failure, all of which could lead to the conclusion of cost-ineffectiveness and over design of current prestressed concrete sleepers. Recently the limit states design method, which appeared in the last century and has been already applied in the design of buildings, bridges, etc, is proposed as a better method for the design of prestressed concrete sleepers. The limit states design has significant advantages compared to the permissible stress design, such as the utilisation of the full strength of the member, and a rational analysis of the probabilities related to sleeper strength and applied loads. This research aims to apply the ultimate limit states design to the prestressed concrete sleeper, namely to obtain the load factors of both static and dynamic loads for the ultimate limit states design equations. However, the sleepers in rail tracks require different safety levels for different types of tracks, which mean the different types of tracks have different load factors of limit states design equations. Therefore, the core tasks of this research are to find the load factors of the static component and dynamic component of loads on track and the strength reduction factor of the sleeper bending strength for the ultimate limit states design equations for four main types of tracks, i.e., heavy haul, freight, medium speed passenger and high speed passenger tracks. To find those factors, the multiple samples of static loads, dynamic loads and their distributions are needed. In the four types of tracks, the heavy haul track has the measured data from Braeside Line (A heavy haul line in Central Queensland), and the distributions of both static and dynamic loads can be found from these data. The other three types of tracks have no measured data from sites and the experimental data are hardly available. In order to generate the data samples and obtain their distributions, the computer based simulations were employed and assumed the wheel-track impacts as induced by different sizes of wheel flats. A valid simulation package named DTrack was firstly employed to generate the dynamic loads for the freight and medium speed passenger tracks. However, DTrack is only valid for the tracks which carry low or medium speed vehicles. Therefore, a 3-D finite element (FE) model was then established for the wheel-track impact analysis of the high speed track. This FE model has been validated by comparing its simulation results with the DTrack simulation results, and with the results from traditional theoretical calculations based on the case of heavy haul track. Furthermore, the dynamic load data of the high speed track were obtained from the FE model and the distributions of both static and dynamic loads were extracted accordingly. All derived distributions of loads were fitted by appropriate functions. Through extrapolating those distributions, the important parameters of distributions for the static load induced sleeper bending moment and the extreme wheel-rail impact force induced sleeper dynamic bending moments and finally, the load factors, were obtained. Eventually, the load factors were obtained by the limit states design calibration based on reliability analyses with the derived distributions. After that, a sensitivity analysis was performed and the reliability of the achieved limit states design equations was confirmed. It has been found that the limit states design can be effectively applied to railway concrete sleepers. This research significantly contributes to railway engineering and the track safety area. It helps to decrease the failure and risks of track structure and accidents; better determines the load range for existing sleepers in track; better rates the strength of concrete sleepers to support bigger impact and loads on railway track; increases the reliability of the concrete sleepers and hugely saves investments on railway industries. Based on this research, many other bodies of research can be promoted in the future. Firstly, it has been found that the 3-D FE model is suitable for the study of track loadings and track structure vibrations. Secondly, the equations for serviceability and damageability limit states can be developed based on the concepts of limit states design equations of concrete sleepers obtained in this research, which are for the ultimate limit states.

Incorporating spatial correlations into multispecies mean-field models

In biology, we frequently observe different species existing within the same environment. For example, there are many cell types in a tumour, or different animal species may occupy a given habitat. In modelling interactions between such species, we often make use of the mean field approximation, whereby spatial correlations between the locations of individuals are neglected. Whilst this approximation holds in certain situations, this is not always the case, and care must be taken to ensure the mean field approximation is only used in appropriate settings. In circumstances where the mean field approximation is unsuitable we need to include information on the spatial distributions of individuals, which is not a simple task. In this paper we provide a method that overcomes many of the failures of the mean field approximation for an on-lattice volume-excluding birth-death-movement process with multiple species. We explicitly take into account spatial information on the distribution of individuals by including partial differential equation descriptions of lattice site occupancy correlations. We demonstrate how to derive these equations for the multi-species case, and show results specific to a two-species problem. We compare averaged discrete results to both the mean field approximation and our improved method which incorporates spatial correlations. We note that the mean field approximation fails dramatically in some cases, predicting very different behaviour from that seen upon averaging multiple realisations of the discrete system. In contrast, our improved method provides excellent agreement with the averaged discrete behaviour in all cases, thus providing a more reliable modelling framework. Furthermore, our method is tractable as the resulting partial differential equations can be solved efficiently using standard numerical techniques.