Queensland Rail

Quarried rock fragments (ballast) constitute one of the most commonly used construction materials in railway engineering practice. Ballast is subjected to high stress levels as well as being always exposed to environmental changes. Unsatisfactory performance of railway tracks is often associated with the loss of cross level, track profile and track alignment. The in situ condition and the engineering behavior of ballast are also important aspects governing the stability and performance of a given railway track structure. This paper presents the findings of a series of isotropically consolidated, triaxial compression tests on two modeled fractions of uniformly graded latite basalt, which is currently being used by the Railway Services Authority (RSA) of New South Wales, Australia, in the construction of new railway tracks. These tests form part of an extended research program sponsored by RSA to study the stress-strain relationships, strength properties and degradation characteristics of various types of railway ballast. The program is associated with the necessity of upgrading railway tracks for the looming Olympics in 2000. Large-scale triaxial equipment has been employed during the testing program, which is formulated to provide specific geotechnical information on the shear strength and the angle of internal friction of ballast as a function of the particle size distribution. The effect of maximum principal stress ratio on the deformation and degradation of ballast is also studied. Nonlinear relationships are developed to describe appropriately the variation of shear strength, angle of internal friction, dilation rate and degree of particle crushing at different confining pressures and principal stress ratios.

Traditional railway foundations or substructures have become increasingly overloaded in recent years, owing to the introduction of faster and heavier trains. A lack of substructure re-engineering has resulted in maintenance cycles becoming more frequent and increasingly expensive. Two significant problems arising from increasing axle loads are differential track settlement and ballast degradation. One potential method of enhancing the substructure is to manipulate the level of ballast confinement. To investigate this possibility, a series of high-frequency cyclic triaxial tests has been conducted to examine the effects of confining pressure and deviator stress magnitude on ballast deformation (permanent and resilient) and degradation. Experimental results indicate that, for each deviator stress considered, an 'optimum' range of confining pressures exists such that degradation is minimised. This range was found to vary from 15–65 kPa for a maximum deviator stress of 230 kPa to 50–140 kPa when deviatoric stresses increase to 750 kPa. Ballast specimens tested at low confining pressures indicative of current in situ conditions were characterised by excessive axial deformations, volumetric dilation, and an unacceptable degree of degradation associated mainly with angular corner breakage. The results suggest that in situ lateral pressures should be increased to counteract the axle loads of heavier trains, and practical methods of achieving increased confinement are suggested.

Keywords: deformation ; gravels ; laboratory tests ; particle crushing/crushability ; repeated loading ... Show All

Purpose The purpose of this study was to examine the relationship between organisational support for career development (OSCD) and employees' career satisfaction. Based on an extended model of social cognitive career theory (SCCT) and an integrative model of proactive behaviours, the study proposed that career management behaviours would mediate the relationship between OSCD and career satisfaction, and between proactive personality and career satisfaction. Design/methodology/approach Public and private sector employees ( N =90) participating in career development activities completed a survey regarding their proactivity, OSCD, career management behaviours and career satisfaction. Findings OSCD, proactive personality and career management behaviours were all positively related to career satisfaction and career management behaviours mediated the relationship between proactive personality and career satisfaction. There was no support for the career management behaviours mediating between OSCD and career satisfaction. Research limitations/implications This study provided support for the extended SCCT model by testing a subset of its proposed relationships using a cross‐sectional approach. The sample surveyed (employees participating in career development activities) and the large proportion of full‐time employees, may limit the generalisability of the findings. Future longitudinal research could more fully test the relationships proposed by the extended SCCT model and include a greater representation of part‐time and casual employees. Practical implications The results suggest that there are benefits for organisations and individuals investing in career development.. First, from an organisational perspective, investing in OSCD may enhance employees' career satisfaction. Second, employees may enhance their own career satisfaction by participating in career management behaviours. Originality/value This study integrated the predictions of two models (an extension of SCCT and a model of proactive behaviours) to test the influence of environmental (OSCD) and individual difference (proactive personality) variables on career satisfaction. Exploring how organisational and individual variables together influence career satisfaction provides a more balanced approach to theoretical development.

Abstract The UN's globally adopted Convention on Biological Diversity coverage target for marine protected areas (MPAs) is ≥10% by 2020. In 2014, the World Parks Congress recommended increasing this to ≥30%. We reviewed 144 studies to assess whether the UN target is adequate to achieve, maximize, or optimize six environmental and/or socioeconomic objectives. Results consistently indicate that protecting several tens‐of‐percent of the sea is required to meet goals (average 37%, median 35%, modal group 21–30%), greatly exceeding the 2.18% currently protected and the 10% target. The objectives we examined were met in 3% of studies with ≤10% MPA coverage, 44% with ≤30% coverage, and 81% with more than half the sea protected. The UN's 10% target appears insufficient to protect biodiversity, preserve ecosystem services, and achieve socioeconomic priorities. As MPA coverages generated from theoretical studies inherently depend on scenario(s) considered, our findings do not represent explicit recommendations but rather provide perspective on policy goals.

Understanding the complex mechanisms of stress transfer and strain accumulation in layers of track substructure under repeated wheel loading is essential to predict the desirable track maintenance cycle as well as the design of the new track. Various finite element and analytical techniques have been developed in the past to understand the behavior of composite track layers subjected to repeated wheel loads. The mechanical behavior of ballast is influenced by several factors, including the track confining pressure, type of aggregates, and the number of loading cycles. A field trial was conducted on an instrumented track at Bulli, New South Wales, Australia, with the specific aims of studying the benefits of a geocomposite installed at the ballast-capping interface, and to evaluate the performance of moderately graded recycled ballast in comparison to traditionally very uniform fresh ballast. It was found that recycled ballast can be effectively reused if reinforced with a geocomposite. It was also found that geocomposite can effectively reduce vertical and lateral strains of the ballast with obvious implications for improved track stability and reduced maintenance costs.

Traditional railway foundations or substructures have become increasingly overloaded in recent years due to the introduction of faster and heavier trains. A lack of substructure re-engineering has resulted in maintenance cycles becoming more frequent and increasingly expensive. Two significant problems arising from increasing axle loads are differential track settlement and ballast degradation. One potential method of enhancing the substructure is by manipulating the level of ballast confinement. To investigate this possibility, a series of high frequency cyclic triaxial tests have been conducted to examine the effects of confining pressure and deviator stress magnitude on ballast deformation (permanent and resilient) and degradation. Experimental results indicate that for each deviator stress considered, an optimum range of confining pressures exists such that degradation is minimised. This range was found to vary from 15 – 65 kPa for a maximum deviator stress of 230 kPa, to 50 – 140 kPa when deviatoric stresses increase to 750 kPa. Ballast specimens tested at low confining pressures indicative of current in-situ conditions were characterised by excessive axial deformations, volumetric dilation and an unacceptable degree of degradation associated mainly with angular corner breakage. The results suggest that in-situ lateral pressures should be increased to counteract the axle loads of heavier trains, and practical methods of achieving increased confinement are suggested.

Importance: There has been wide interest in using artificial intelligence (AI)-based grading of retinal images to identify diabetic retinopathy, but such a system has never been deployed and evaluated in clinical practice. Objective: To describe the performance of an AI system for diabetic retinopathy deployed in a primary care practice. Design, Setting, and Participants: Diagnostic study of patients with diabetes seen at a primary care practice with 4 physicians in Western Australia between December 1, 2016, and May 31, 2017. A total of 193 patients consented for the study and had retinal photographs taken of their eyes. Three hundred eighty-six images were evaluated by both the AI-based system and an ophthalmologist. Main Outcomes and Measures: Sensitivity and specificity of the AI system compared with the gold standard of ophthalmologist evaluation. Results: Of the 193 patients (93 [48%] female; mean [SD] age, 55 [17] years [range, 18-87 years]), the AI system judged 17 as having diabetic retinopathy of sufficient severity to require referral. The system correctly identified 2 patients with true disease and misclassified 15 as having disease (false-positives). The resulting specificity was 92% (95% CI, 87%-96%), and the positive predictive value was 12% (95% CI, 8%-18%). Many false-positives were driven by inadequate image quality (eg, dirty lens) and sheen reflections. Conclusions and Relevance: The results demonstrate both the potential and the challenges of using AI systems to identify diabetic retinopathy in clinical practice. Key challenges include the low incidence rate of disease and the related high false-positive rate as well as poor image quality. Further evaluations of AI systems in primary care are needed.

Familial hyperparathyroidism is not uncommon in clinical endocrine practice. It encompasses a spectrum of disorders including multiple endocrine neoplasia types 1 (MEN1) and 2A, hyperparathyroidism-jaw tumour syndrome (HPT-JT), familial hypocalciuric hypercalcaemia (FHH), and familial isolated hyperparathyroidism (FIHP). Distinguishing among the five syndromes is often difficult but has profound implications for the management of patient and family. The availability of specific genetic testing for four of the syndromes has improved diagnostic accuracy and simplified family monitoring in many cases but its current cost and limited accessibility require rationalisation of its use. No gene has yet been associated exclusively with FIHP. FIHP phenotypes have been associated with mutant MEN1 and calcium-sensing receptor (CASR) genotypes and, very recently, with mutation in the newly identified HRPT2 gene. The relative proportions of these are not yet clear. We report results of MEN1, CASR, and HRPT2 genotyping of 22 unrelated subjects with FIHP phenotypes. We found 5 (23%) with MEN1 mutations, four (18%) with CASR mutations, and none with an HRPT2 mutation. All those with mutations had multiglandular hyperparathyroidism. Of the subjects with CASR mutations, none were of the typical FHH phenotype. These findings strongly favour a recommendation for MEN1 and CASR genotyping of patients with multiglandular FIHP, irrespective of urinary calcium excretion. However, it appears that HRPT2 genotyping should be reserved for cases in which other features of the HPT-JT phenotype have occurred in the kindred. Also apparent is the need for further investigation to identify additional genes associated with FIHP.

The ballast and its engineering behaviour have a key role in governing the stability and performance of railway tracks. The deformation and degradation behaviour of ballast under static and dynamic loads was studied based on large-scale triaxial testing. The possible use of different types of geosynthetics to improve the performance of fresh and recycled ballast was also investigated. The research findings showed that the inclusion of geosynthetics improves the performance of ballasted tracks. Le ballast et son comportement mécanique ont une influence importante sur la stabilité et la performance des voies ferrées. Nous avons étudié le comportement de détérioration et de déformation du ballast sous charge statiques et dynamiques en nous basant sur des essais triaxiaux à grande échelle. Nous avons également étudié la possibilité d'utiliser divers types de géosynthétiques pour améliorer la performance du ballast neuf et recyclé. Les résultats de cette recherche ont montré que l'adjonction de géosynthétiques améliorait la performance des voies ballastées.

This assessment by the Environmental Effects Assessment Panel (EEAP) of the Montreal Protocol under the United Nations Environment Programme (UNEP) evaluates the effects of ultraviolet (UV) radiation on human health within the context of the Montreal Protocol and its Amendments. We assess work published since our last comprehensive assessment in 2018. Over the last four years gains have been made in knowledge of the links between sun exposure and health outcomes, mechanisms, and estimates of disease burden, including economic impacts. Of particular note, there is new information about the way in which exposure to UV radiation modulates the immune system, causing both harms and benefits for health. The burden of skin cancer remains high, with many lives lost to melanoma and many more people treated for keratinocyte cancer, but it has been estimated that the Montreal Protocol will prevent 11 million cases of melanoma and 432 million cases of keratinocyte cancer that would otherwise have occurred in the United States in people born between 1890 and 2100. While the incidence of skin cancer continues to rise, rates have stabilised in younger populations in some countries. Mortality has also plateaued, partly due to the use of systemic therapies for advanced disease. However, these therapies are very expensive, contributing to the extremely high economic burden of skin cancer, and emphasising the importance and comparative cost-effectiveness of prevention. Photodermatoses, inflammatory skin conditions induced by exposure to UV radiation, can have a marked detrimental impact on the quality of life of sufferers. More information is emerging about their potential link with commonly used drugs, particularly anti-hypertensives. The eyes are also harmed by over-exposure to UV radiation. The incidence of cataract and pterygium is continuing to rise, and there is now evidence of a link between intraocular melanoma and sun exposure. It has been estimated that the Montreal Protocol will prevent 63 million cases of cataract that would otherwise have occurred in the United States in people born between 1890 and 2100. Despite the clearly established harms, exposure to UV radiation also has benefits for human health. While the best recognised benefit is production of vitamin D, beneficial effects mediated by factors other than vitamin D are emerging. For both sun exposure and vitamin D, there is increasingly convincing evidence of a positive role in diseases related to immune function, including both autoimmune diseases and infection. With its influence on the intensity of UV radiation and global warming, the Montreal Protocol has, and will have, both direct and indirect effects on human health, potentially changing the balance of the risks and benefits of spending time outdoors.

Prestressed concrete sleepers (or railroad ties) are the crosstie beam support in railway track systems. They are designed and constructed under flexural constraints in order to carry and transfer the dynamic wheel loads from the rails to the ground. Under perfect wheel and rail conditions, the dynamic loading on railway tracks could be treated as a quasi-static load using a dynamic impact factor. The current design method for the prestressed concrete sleepers taking into account the quasi-static effect is based on allowable stress where crack initiation is not permitted. In reality, the impact events are often detected due to the uncertainties of wheel or rail abnormalities such as flat wheels, dipped rails, etc. These loads are of very high magnitude but short duration. Over the design life span of the prestressed concrete sleepers, there exists the feasibility of extreme and repeated impact loading events. These have led to two proposed limit states for the consideration of structural engineers: ultimate limit states and fatigue limit states. Prestressing techniques have been long used to maintain the high endurance of the sleepers under repeated impact cycles. In spite of the most common use of the prestressed concrete sleepers, their impact behavior and capacity under the repetitions of severe impact loads are unclear. This paper presents the experimental investigation aimed at understanding the dynamic crack propagations in prestressed concrete sleepers in railway track structures under repeated impact loading. The impact forces have been correlated against the probabilistic track force distribution obtained from an Australian heavy haul rail network. The effects of track environment including soft and hard tracks are highlighted in this paper.

BACKGROUND: Schistosomes are able to survive for prolonged periods in the blood system, despite continuous contact with coagulatory factors and mediators of the host immune system. Protease inhibitors likely play a critical role in host immune modulation thereby promoting parasite survival in this extremely hostile environment. Even though Kunitz type serine protease inhibitors have been shown to play important physiological functions in a range of organisms these proteins are less well characterised in parasitic helminths. METHODS: We have cloned one gene sequence from S. mansoni, Smp_147730 (SmKI-1) which is coded for single domain Kunitz type protease inhibitor, E. coli-expressed and purified. Immunolocalisation and western blotting was carried out using affinity purified polyclonal anti-SmKI-1 murine antibodies to determine SmKI-1 expression in the parasite. Protease inhibitor assays and coagulation assays were performed to evaluate the functional roles of SmKI-1. RESULTS: SmKI-1 is localised in the tegument of adult worms and the sub-shell region of eggs. Furthermore, this Kunitz protein is secreted into the host in the ES products of the adult worm. Recombinant SmKI-1 inhibited mammalian trypsin, chymotrypsin, neutrophil elastase, FXa and plasma kallikrein with IC50 values of 35 nM, 61 nM, 56 nM, 142 nM and 112 nM, respectively. However, no inhibition was detected for pancreatic elastase or cathepsin G. SmKI-1 (4 μM) delayed blood clot formation, reflected in an approximately three fold increase in activated partial thromboplastin time and prothrombin time. CONCLUSIONS: We have functionally characterised the first Kunitz type protease inhibitor (SmKI-1) from S. mansoni and show that it has anti-inflammatory and anti-coagulant properties. SmKI-1 is one of a number of putative Kunitz proteins in schistosomes that have presumably evolved as an adaptation to protect these parasites from the defence mechanisms of their mammalian hosts. As such they may represent novel vaccine candidates and/or drug targets for schistosomiasis control.

‘Big data’ obtained from wayside detection systems and sensors installed on board a train show that actual loading history for a railway track is rather dynamic and transient. The dynamic loadings due to train and track interactions redistribute from the rails to the rail pad, from the rail pad to the railway sleeper, and from the railway sleeper to the underlying ground. Dynamic content redistributed onto each layer of track is also filtered by energy dissipation characteristic of materials and structures. As a critical infrastructure, railway turnout is a structural grillage system used to divert a train to other directions or other tracks. The wheel–rail contact over the crossing transfer zone often causes detrimental impact loads that rapidly deteriorate the turnout and its components. The dynamic responses of wheel–rail interaction depend largely on the non-smooth trajectory or wearing condition of crossing geometry. In reality, a railway line spreads over a large distance and monitoring such rail infrastructure is one of the challenges in rail industry. This paper presents a methodology and application to evaluate and monitor the structural deterioration of railway turnout systems in an Australian urban rail network. The method has integrated numerical train/track simulations, axle box acceleration and ride quality data obtained from the calibrated track inspection vehicle “AK Car”.

The complete genome of a novel Circovirus isolated from an Australian raven (Corvus coronoides) with feather lesions similar to those that occur in psittacine beak and feather disease is reported. Degenerate polymerase chain reaction primers were designed to amplify and sequence novel Circovirus DNA from affected feathers. Sequence analysis indicated that the tentatively named raven circovirus (RaCV) was 1898 nucleotides in size with two major open reading frames synonymous with other avian circoviruses, ORF C1 and ORF V1, likely to encode a putative capsid protein (Cap) and replicase-associated protein (Rep), respectively. In common with other circoviruses was the conservation of several nucleotide structures and amino acid motifs implicated in virus replication. Comparison with other members of the Circoviridae demonstrated that RaCV shares the greatest sequence homology with canary circovirus (CaCV) and pigeon circovirus (PiCV) and was more distantly related to the beak and feather disease virus, goose circovirus, duck circovirus and the two porcine circoviruses, PCV1 and PCV2. Phylogenetic analysis of the genome and the putative Cap and Rep proteins provided further evidence of the close relationship of RaCV with CaCV and PiCV.

Railway ballast breaks down and deteriorates progressively under train cyclic loading, and soft formation soil fails due to repetitive stress, leading to costly rail track maintenance. Using geosynthetics, track conditions can be improved and maintenance costs can be reduced. This paper addresses the potential use of geosynthetics for improving the deformation characteristics of rail ballast and formation soil. The prospective use of different types of geosynthetics was investigated using a large-scale prismoidal triaxial rig, and a plane strain finite element analysis (PLAXIS) of the rig was carried out to obtain the optimum location of geosynthetics in rail track substructure. A large-scale consolidometer was also employed to determine the effect of prefabricated vertical drains (PVDs) in optimising the accelerated primary consolidation of track soft formation. This paper also includes a section where recommendations are made on how to prepare the stability of rail tracks on surface formation soils considerably disturbed/remoulded by the Asian tsunami in Sri Lanka. The research findings reveal that geosynthetics have a good potential for resilient track construction and for reducing the cost of track maintenance. Le ballast d'infrastructure ferroviaire se fracture et se détériore progressivement sous le chargement cyclique des trains et le sol de formation molle se fracture en raison de la charge répétée. Ces dégradations sont à l'origine d'une maintenance coûteuse des voies ferrées. Les conditions de ces infrastructures peuvent s'améliorer et le coût de leur maintenance diminuer grâce à l'utilisation de la géosynthétique. Cet article illustre l'application potentielle de la géosynthétique pour l'amélioration des caractéristiques de déformation du ballast des voies ferroviaires et du sol de formation. L'utilisation prospective de différents types de géosynthétique est étudiée au moyen d'un montage triaxial prismoïde et une analyse en éléments finis en déformation plane (PLAXIS) du montage est réalisée pour obtenir l'emplacement optimal de la géosynthétique au niveau de la sous-structure de la voie ferrée. Un consolidomètre de grande échelle a également permis de déterminer le role des drains verticaux préfabriqués (DVP) dans l'optimisation de la consolidation primaire accélérée de la formation molle de la voie. L'article présente également une section comportant des recommandations sur les moyens de préparer la stabilité des voies ferrées sur le sols de formation en surface considérablement perturbés / remodelés par le tsunami asiatique qui a touché le Sri Lanka. Les résultats de ces travaux indiquent que la géosynthétique se révèle prometteuse en termes de construction de voies ferrées é lastiques et de réduction des coûts de maintenance des voies.

In coastal Australia, high population density and increased traffic volumes have promoted rapid expansion of urban transportation infrastructure including railways. Coastal soft clays pose significant construction challenges. Therefore, the search for innovative ground improvement techniques imperative for more resilient and sustainable transport infrastructure has become an obvious priority in research and development. Use of artificial inclusions such as polymeric geosynthetics and energy-absorbing shock mats is described in this paper as a suitable alternative for reducing unacceptable track degradation and for ensuring sustainable track alignment. An extensive monitoring programme was undertaken on fully instrumented track sections constructed near Singleton, New South Wales, Australia. Four types of geosynthetics were installed at the ballast–capping interface of track sections located on different types of subgrades. It was found that geogrids could decrease the vertical settlement of the ballast layer with the obvious benefits of improved track stability and decreased cost of maintenance. It was also found that the effectiveness of reinforcing geogrids is greater when the subgrade is soft.

Three types of wagon connection coupling systems are evaluated in a train simulation model consisting of 107 vehicles. The three wagon connection coupling systems are auto-couplers with standard draft gears, auto-couplers with draft gears with wedge unlocking features, and the traditional drawhook buffer system. The train is made up of 103 wagons and 4 locomotives. The locomotives are placed in groups of two at the head and mid-train positions. Dynamic response and fatigue damage is compared for a control disturbance on a crest and on a flat track section. The effect of coupling-free travel (slack) is also investigated.

OBJECTIVE: To synthesise quantitative data on the effects of rural background and experience in rural areas during medical training on the likelihood of general practitioners practising and remaining in rural areas. STUDY DESIGN: Systematic review and meta-analysis of the effects of rural pipeline factors (rural background; rural clinical and education experience during undergraduate and postgraduate/vocational training) on likelihood of later general practice in rural areas. DATA SOURCES: MEDLINE (Ovid), EMBASE, Informit Health Collection, and ERIC electronic database records published to September 2018; bibliographies of retrieved articles; grey literature. DATA SYNTHESIS: Of 6709 publications identified by our search, 27 observational studies were eligible for inclusion in our systematic review; when appropriate, data were pooled in random effects models for meta-analysis. Study quality, assessed with the Newcastle-Ottawa scale, was very good or good for 24 studies, satisfactory for two, and unsatisfactory for one. Meta-analysis indicated that GPs practising in rural communities was significantly associated with having a rural background (odds ratio [OR], 2.71; 95% CI, 2.12-3.46; ten studies) and with rural clinical experience during undergraduate (OR, 1.75; 95% CI, 1.48-2.08; five studies) and postgraduate training (OR, 4.57; 95% CI, 2.80-7.46; eight studies). CONCLUSION: GPs with rural backgrounds or rural experience during undergraduate or postgraduate medical training are more likely to practise in rural areas. The effects of multiple rural pipeline factors may be cumulative, and the duration of an experience influences the likelihood of a GP commencing and remaining in rural general practice. These findings could inform government-led initiatives to support an adequate rural GP workforce. PROTOCOL REGISTRATION: PROSPERO, CRD42017074943 (updated 1 February 2018).

Poor lamb survival pre-weaning is a major source of reproductive inefficiency in Australian sheep flocks. While nutrition and management options have been extensively researched and promoted to improve lamb survival, the present review focuses on the prospects for obtaining genetic gain and helps identify selection strategies for boosting such gains to improve overall reproductive efficiency in the Australian sheep industry. Estimated heritability for lamb survival using linear model analysis is low, although use of threshold models suggests that heritability could be higher, which, if true, could help explain the substantial genetic gains obtained in long-term selection experiments. Epigenetic mechanisms may hinder selection and quantitative trait-loci identification through confounding and/or masking genetic variances and co-variances. With sufficient information, these effects could be considered in genetic evaluations by identifying those components that are amenable to selection. Regarding indirect selection, finding effective criteria for improving lamb survival has proved elusive. Most measures of maternal behaviour, temperament and lambing difficulty researched are poorly correlated genetically with lamb survival. Of lamb behaviours and thermo-genic indicators studied, latency to bleat following handling by humans is moderately genetically correlated with lamb survival, as is neonatal rectal temperature. Industry application remains to be adequately explored for the more promising of these measures. Finally, in lieu of direct selection for lamb survival, there is merit in selecting for multiple-rearing ability or its equivalent, possibly with additional selection criteria for lamb survival and reproductive efficiency.