Pull-through failures of crest-fixed steel claddings initiated by transverse splitting

Crest-fixed steel claddings made of thin, high strength steel often suffer from local pull-through failures at their screw connections during high wind events such as storms and hurricanes. Currently there aren't any adequate design provisions for these cladding systems except for the expensive testing provisions. Since the local pull-through failures in the less ductile steel claddings are initiated by transverse splitting at the fastener hole, analytical studies have not been able to determine the pull-through failure loads. Analytical studies could be used if a reliable splitting criterion is available. Therefore a series of two-span cladding tests was conducted on a range of crest-fixed steel cladding systems under simulated wind uplift loads. The strains in the sheeting around the critical fastener holes were measured until the pull-through failure. This paper presents the details of the experimental investigation and the results including a strain criterion for the local pull-through failure.

Cyclic pull-out strength of steel roof and wall cladding systems

When crest-fixed thin steel roof cladding systems are subjected to wind uplift, local pull-through or pull-out failures occur prematurely at their screwed connections. During high wind events such as storms and cyclones these localised failures then lead to severe damage to buildings and their contents. In recent times, the use of thin steel battens/purlins has increased considerably. This has made the pull-out failures more critical in the design of steel cladding systems. Recent research has developed a design formula for the static pull-out strength of steel cladding systems. However, the effects of fluctuating wind uplift loading that occurs during high wind events are not known. Therefore a series of constant amplitude cyclic tests has been undertaken on connections between steel battens made of different thicknesses and steel grades, and screw fasteners with varying diameter and pitch. This paper presents the details of these cyclic tests and the results.

Ratchetting of railhead in the vicinity of the gap of the insulated rail joints

Insulated Rail Joints (IRJs) are designed to electrically isolate two rails in rail tracks to control the signalling system for safer train operations. Unfortunately the gapped section of the IRJs is structurally weak and often fails prematurely especially in heavy haul tracks, which adversely affects service reliability and efficiency. The IRJs suffer from a number of failure modes; the railhead ratchetting at the gap is, however, regarded as the root cause and attended to in this thesis. Ratchetting increases with the increase in wheel loads; in the absence of a life prediction model, effective management of the IRJs for increased wagon wheel loads has become very challenging. Therefore, the main aim of this thesis is to determine method to predict IRJs' service life. The distinct discontinuity of the railhead at the gap makes the Hertzian theory and the rolling contact shakedown map, commonly used in the continuously welded rails, not applicable to examine the metal ratchetting of the IRJs. Finite Element (FE) technique is, therefore, used to explore the railhead metal ratchetting characteristics in this thesis, the boundary conditions of which has been determined from a full scale study of the IRJ specimens under rolling contact of the loaded wheels. A special purpose test set up containing full-scale wagon wheel was used to apply rolling wheel loads on the railhead edges of the test specimens. The state of the rail end face strains was determined using a non-contact digital imaging technique and used for calibrating the FE model. The basic material parameters for this FE model were obtained through independent uniaxial, monotonic tensile tests on specimens cut from the head hardened virgin rails. The monotonic tensile test data have been used to establish a cyclic load simulation model of the railhead steel specimen; the simulated cyclic load test has provided the necessary data for the three decomposed kinematic hardening plastic strain accumulation model of Chaboche. A performance based service life prediction algorithm for the IRJs was established using the plastic strain accumulation obtained from the Chaboche model. The predicted service lives of IRJs using this algorithm have agreed well with the published data. The finite element model has been used to carry out a sensitivity study on the effects of wheel diameter to the railhead metal plasticity. This study revealed that the depth of the plastic zone at the railhead edges is independent of the wheel diameter; however, large wheel diameter is shown to increase the IRJs' service life.

XML clustering and its application to XML transformation

The continuous growth of the XML data poses a great concern in the area of XML data management. The need for processing large amounts of XML data brings complications to many applications, such as information retrieval, data integration and many others. One way of simplifying this problem is to break the massive amount of data into smaller groups by application of clustering techniques. However, XML clustering is an intricate task that may involve the processing of both the structure and the content of XML data in order to identify similar XML data. This research presents four clustering methods, two methods utilizing the structure of XML documents and the other two utilizing both the structure and the content. The two structural clustering methods have different data models. One is based on a path model and other is based on a tree model. These methods employ rigid similarity measures which aim to identifying corresponding elements between documents with different or similar underlying structure. The two clustering methods that utilize both the structural and content information vary in terms of how the structure and content similarity are combined. One clustering method calculates the document similarity by using a linear weighting combination strategy of structure and content similarities. The content similarity in this clustering method is based on a semantic kernel. The other method calculates the distance between documents by a non-linear combination of the structure and content of XML documents using a semantic kernel. Empirical analysis shows that the structure-only clustering method based on the tree model is more scalable than the structure-only clustering method based on the path model as the tree similarity measure for the tree model does not need to visit the parents of an element many times. Experimental results also show that the clustering methods perform better with the inclusion of the content information on most test document collections. To further the research, the structural clustering method based on tree model is extended and employed in XML transformation. The results from the experiments show that the proposed transformation process is faster than the traditional transformation system that translates and converts the source XML documents sequentially. Also, the schema matching process of XML transformation produces a better matching result in a shorter time.

Chemotherapy-induced nausea and vomiting : a review to inform clinical practice

Chemotherapy-induced nausea and vomiting (CINV) is a common sideeffect of cytotoxic treatment and despite the widespread use of anti-emetic medication, it continues to affect a significant proportion of patients with up to 23% and 73% of chemotherapy patients still experiencing vomiting and nausea symptoms, respectively. This is of particular concern in oncology patients as nausea and vomiting may result in malnutrition, decreased quality of life and in extreme cases, treatment stoppage. Therefore, the primary aim of this paper was to inform clinicians on the current literature regarding CINV including its effect on the patient, its pathophysiology, and current treatment options. In addition, this review will also discuss the usage of dietetic interventions as well as less utilised, novel interventions such as oral ginger extracts in the treatment of CINV. In order to address these issues, a systematic literature search was conducted using Pubmed, CINAHL, MEDLINE, Embase, and Health Source (Nursing/Academic Edition). A key finding of this review was that common dietary strategies (e.g. eating slowly, avoiding fatty foods) seem to be solely based on professional opinion as no clinical trials investigating these strategies were identified. In contrast, ginger extracts were found to possess several viable mechanisms that interact with CINV progression including 5-HT3, Substance P and acetylcholine receptor antagonism; anti-inflammatory and antioxidant properties; and gastrointestinal motility and gastric emptying modulation. In conclusion, research investigating dietetic interventions in the management of CINV is sparse and requires further investigation while novel intervention such as ginger, possess multiple mechanisms that may benefit CINV management. This review will discuss the prevalence and significance of CINV, dietetic and novel treatment options, and provide implications for clinical practise and future research.

Ginger - mechanism of action in chemotherapy-induced nausea and vomiting: A review

Despite advances in anti-emetic therapy, chemotherapy-induced nausea and vomiting (CINV) still poses a significant burden to patients undergoing chemotherapy. Nausea, in particular, is still highly prevalent in this population. Ginger has been traditionally used as a folk remedy for gastrointestinal complaints and has been suggested as a viable adjuvant treatment for nausea and vomiting in the cancer context. Substantial research has revealed ginger to possess properties that could exert multiple beneficial effects on chemotherapy patients who experience nausea and vomiting. Bioactive compounds within the rhizome of ginger, particularly the gingerol and shogaol class of compounds, interact with several pathways that are directly implicated in CINV in addition to pathways that could play secondary roles by exacerbating symptoms. These properties include 5-HT3, substance P and acetylcholine receptor antagonism; anti-inflammatory properties; and modulation of cellular redox signalling, vasopressin release, gastrointestinal motility, and gastric emptying rate. This review outlines these proposed mechanisms by discussing the results of clinical, in vitro and animal studies both within the chemotherapy context and in other relevant fields. The evidence presented in this review indicates that ginger possesses multiple properties that could be beneficial in reducing chemotherapy-induced nausea and vomiting.

Cryotherapy for docetaxel-induced hand and nail toxicity: Randomised control trial

Purpose This study investigated the efficacy and safety of cryotherapy, in the form of frozen gel gloves, in relation to docetaxel-induced hand and fingernail toxicities. Patients and methods After piloting with 21 patients, a consecutive series sample of patients (n=53) prescribed docetaxel every three weeks, for a minimum of three cycles, was enrolled in this randomised control trial. Participants acted as their own control, with the frozen gel glove worn on one randomised hand for 15 minutes prior to infusion, for the duration of the infusion, and for 15 minutes of after completion of treatment. Hand and nail toxicities were evaluated by two blinded assessors according to CTCAE.v4 criteria. To assess the potential for cross-infection of multi-use gloves, microbial culture and sensitivity swabs were taken of each glove at every tenth use. Results Of the 53 participants enrolled in the main study, 21 provided evaluable data. There was a 60% withdrawal rate due to patient discomfort with the intervention. The mean incidence and severity of toxicities in all evaluable cycles in control and intervention hands respectively were erythroderma Grade 1 (5%/5%); nail discolouration Grade 1 (81%/67%); nail loss Grade 1 (19%/19%) and nail ridging Grade 1 (57%/57%). No significant differences were determined between hand conditions in terms of time to event, nor in terms of toxicity in gloved and non-gloved hands. Conclusion While cryotherapy in the form of frozen gloves for the cutaneous toxicities associated with docetaxel is safe, its limited efficacy, patient discomfort and some logistical issues preclude its use in our clinical setting.

Understanding preconditions for digital school transformation

While over the past decade many Australian schools have come to understand the transformative potential of digitally-rich teaching and learning, traditional models of schooling continue to dominate. Even with significant investment in the area, both in terms of digital resourcing and teacher professional development, innovation has generally only occurred in individual classrooms or ‘pockets’ in schools. This article discusses three interdependent conditions which need to exist as a foundation in order to facilitate the opportunity for transformation from traditional to digitally-rich ways of working in primary, middle and secondary schools or colleges. Distributed and transformational leadership approaches are critiqued with core elements identified which facilitate change. The establishment of a vision is identified and discussed as a fundamental driver and rudder for school transformation. The importance of creating and maintaining urgency to compel a school community to adopt and embed change is unpacked. This report concludes with a synthesis of the three preconditions and recommendations for proponents of digital school transformation.

Cyclooxygenase-2-linked attenuation of hypoxia-induced pulmonary hypertension and intravascular thrombosis

Exogenous prostacyclin is effective in reducing pulmonary vascular resistance in some forms of human pulmonary hypertension (PH). To explore whether endogenous prostaglandins played a similar role in pulmonary hypertension, we examined the effect of deleting cyclooxygenase (COX)-gene isoforms in a chronic hypoxia model of PH. Pulmonary hypertension, examined by direct measurement of right ventricular end systolic pressure (RVESP), right ventricular hypertrophy (n = 8), and hematocrit (n = 3), was induced by 3 weeks of hypobarichypoxia in wild-type and COX-knockout (KO) mice. RVESP was increased in wild-type hypoxic mice compared with normoxic controls (24.4 ± 1.4 versus 13.8 ± 1.9 mm Hg; n = 8; p < 0.05). COX-2 KO mice showed a greater increase in RVESP following hypoxia (36.8 ± 2.7 mm Hg; p < 0.05). Urinary thromboxane (TX)B2 excretion increased following hypoxia (44.6 ± 11.1 versus 14.7 ± 1.8 ng/ml; n = 6; p < 0.05), an effect that was exacerbated by COX-2 gene disruption (54.5 ± 10.8 ng/ml; n = 6). In contrast, the increase in 6-keto-prostacyclin1α excretion following hypoxia was reduced by COX-2 gene disruption (29 ± 3 versus 52 ± 4.6 ng/ml; p < 0.01). Tail cut bleed times were lower following hypoxia, and there was evidence of intravascular thrombosis in lung vessels that was exacerbated by disruption of COX-2 and reduced by deletion of COX-1. The TXA2/endoperoxide receptor antagonist ifetroban (50 mg/kg/day) offset the effect of deleting the COX-2 gene, attenuating the hypoxia-induced rise in RVESP and intravascular thrombosis. COX-2 gene deletion exacerbates pulmonary hypertension, enhances sensitivity to TXA2, and induces intravascular thrombosis in response to hypoxia. The data provide evidence that endogenous prostaglandins modulate the pulmonary response to hypoxia. Copyright © 2008 by The American Society for Pharmacology and Experimental Therapeutics.

Chemotherapy induced reversible posterior leukoencephalopathy syndrome

The reversible posterior leukoencephalopathy syndrome (RPLES) is a condition characterised by reversible neurological and radiological findings that has been associated with use of immunosuppressive, chemotherapeutic and more recently novel targeted therapies. We describe the case of a 50-year-old woman with advanced non-small cell lung cancer who developed status epilepticus shortly after receiving cisplatin and gemcitabine chemotherapy. The clinical, radiological and EEG findings during and post event are presented and are in keeping with a diagnosis of RPLES. Early recognition of this rare syndrome, supportive management and withdrawal of the offending agent appear to result in a reversal of the manifestations described. © 2007 Elsevier Ireland Ltd. All rights reserved.

Effect of text type on near work-induced contrast adaptation in myopic and emmetropic young adults

Purpose Contrast adaptation has been speculated to be an error signal for emmetropization. Myopic children exhibit higher contrast adaptation than emmetropic children. This study aimed to determine whether contrast adaptation varies with the type of text viewed by emmetropic and myopic young adults. Methods Baseline contrast sensitivity was determined in 25 emmetropic and 25 spectacle-corrected myopic young adults for 0.5, 1.2, 2.7, 4.4, and 6.2 cycles per degree (cpd) horizontal sine wave gratings. The adults spent periods looking at a 6.2 cpd high-contrast horizontal grating and reading lines of English and Chinese text (these texts comprised 1.2 cpd row and 6 cpd stroke frequencies). The effects of these near tasks on contrast sensitivity were determined, with decreases in sensitivity indicating contrast adaptation. Results Contrast adaptation was affected by the near task (F2,672 = 43.0; P < 0.001). Adaptation was greater for the grating task (0.13 ± 0.17 log unit, averaged across all frequencies) than reading tasks, but there was no significant difference between the two reading tasks (English 0.05 ± 0.13 log unit versus Chinese 0.04 ± 0.13 log unit). The myopic group showed significantly greater adaptation (by 0.04, 0.04, and 0.05 log units for English, Chinese, and grating tasks, respectively) than the emmetropic group (F1,48 = 5.0; P = 0.03). Conclusions In young adults, reading Chinese text induced similar contrast adaptation as reading English text. Myopes exhibited greater contrast adaptation than emmetropes. Contrast adaptation, independent of text type, might be associated with myopia development.

Cross-sectional survey of the health behaviour of southeast Queensland women with cancer-treatment induced menopause : Implications for cancer and primary care nurses

Purpose Women who experience cancer treatment-induced menopause are at risk of long-term chronic morbidity. This risk can be prevented or offset with adherence to health promotion and risk reduction guidelines. The purpose of this study was to explore health behaviours in younger female survivors of cancer and the variables (quality of life and psychological distress) believed to moderate health behaviours. Design Cross-sectional survey of a convenience sample of women (n = 85) in southeast Queensland. Methods Health behaviour and health status were elicited with items from the Australian Health Survey and the Behavioural Risk Factor Surveillance System. The WHO Quality of Life (Brief) measured participants’ self-reported quality of life and their satisfaction with their health. The Brief Symptom Inventory-18 measured psychological distress. Findings Higher self-reported health status was associated with regular exercise and better quality of life. However, a substantial proportion of participants did not engage in the physical activity, dietary or cervical screening practices recommended by Australian guidelines. Conclusions The participants require education regarding the benefits of diet, exercise, weight loss and decreased alcohol intake, as well as information on future health risks and possible comorbidities. These education sessions could be addressed by a nurse-led health promotion model of care at the time of discharge or in the community.

Vorinostat/SAHA-induced apoptosis in malignant mesothelioma is FLIP/caspase 8-dependent and HR23B-independent

Introduction: Malignant pleural mesothelioma (MPM) is a rapidly fatal malignancy that is increasing in incidence. The caspase 8 inhibitor FLIP is an anti-apoptotic protein over-expressed in several cancer types including MPM. The histone deacetylase (HDAC) inhibitor Vorinostat (SAHA) is currently being evaluated in relapsed mesothelioma. We examined the roles of FLIP and caspase 8 in regulating SAHA-induced apoptosis in MPM. Methods: The mechanism of SAHA-induced apoptosis was assessed in 7 MPM cell lines and in a multicellular spheroid model. SiRNA and overexpression approaches were used, and cell death was assessed by flow cytometry, Western blotting and clonogenic assays. Results: RNAi-mediated FLIP silencing resulted in caspase 8-dependent apoptosis in MPM cell line models. SAHA potently down-regulated FLIP protein expression in all 7 MPM cell lines and in a multicellular spheroid model of MPM. In 6/7 MPM cell lines, SAHA treatment resulted in significant levels of apoptosis induction. Moreover, this apoptosis was caspase 8-dependent in all six sensitive cell lines. SAHA-induced apoptosis was also inhibited by stable FLIP overexpression. In contrast, down-regulation of HR23B, a candidate predictive biomarker for HDAC inhibitors, significantly inhibited SAHA-induced apoptosis in only 1/6 SAHA-sensitive MPM cell lines. Analysis of MPM patient samples demonstrated significant inter-patient variations in FLIP and caspase 8 expressions. In addition, SAHA enhanced cisplatin-induced apoptosis in a FLIP-dependent manner. Conclusions: These results indicate that FLIP is a major target for SAHA in MPM and identifies FLIP, caspase 8 and associated signalling molecules as candidate biomarkers for SAHA in this disease. © 2011 Elsevier Ltd. All rights reserved.

Oxidative stress induced lung cancer and COPD : opportunities for epigenetic therapy

Reactive oxygen species (ROS) form as a natural by-product of the normal metabolism of oxygen and play important roles within the cell. Under normal circumstances the cell is able to maintain an adequate homeostasis between the formation of ROS and its removal through particular enzymatic pathways or via antioxidants. If however, this balance is disturbed a situation called oxidative stress occurs. Critically, oxidative stress plays important roles in the pathogenesis of many diseases, including cancer. Epigenetics is a process where gene expression is regulated by heritable mechanisms that do not cause any direct changes to the DNA sequence itself, and disruption of epigenetic mechanisms has important implications in disease. Evidence is emerging that histone deacetylases (HDACs) play decisive roles in regulating important cellular oxidative stress pathways including those involved with sensing oxidative stress and those involved with regulating the cellular response to oxidative stress. In particular aberrant regulation of these pathways by HDACs may play critical roles in cancer progression. In this review we discuss the current evidence linking epigenetics and oxidative stress and cancer, using chronic obstructive pulmonary disease and non-small cell lung cancer to illustrate the importance of epigenetics on these pathways within these disease settings. © 2009 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.