A Novel Methodology to Characterize the Constitutive Behaviour of Polyethylene terephthalate for the Stretch Blow Moulding process

The stretch blow moulding (SBM) process is the main method for the mass production of PET containers. And understanding the constitutive behaviour of PET during this process is critical for designing the optimum product and process. However due to its nonlinear viscoelastic behaviour, the behaviour of PET is highly sensitive to its thermomechanical history making the task of modelling its constitutive behaviour complex. This means that the constitutive model will be useful only if it is known to be valid under the actual conditions of interest to the SBM process. The aim of this work was to develop a new material characterization method providing new data for the deformation behaviour of PET relevant to the SBM process. In order to achieve this goal, a reliable and robust characterization method was developed based on an instrumented stretch rod and a digital image correlation system to determine the stress-strain relationship of material in deforming preforms during free stretch-blow tests. The effect of preform temperature and air mass flow rate on the deformation behaviour of PET was also investigated.

A microstructure based analytical model for tensile twinning in a rod textured Mg alloy

Abstract A model for tensile twinning during the compression of rod textured magnesium is developed based on the idea that these twins nucleate at grain boundaries and that when the twin number density per grain is low these twins readily give rise to the formation of other 'interaction' twins in adjacent grains. Experimental observations of twin aspect ratios measured at a single grain size and twin number densities measured over four grain sizes were used to determine model material parameters. Using these, the model provides reasonable predictions for the observed magnitudes and trends for the following observations:Effect of grain size and stress on twin volume fraction, fractional twin length and the fraction of twin contact.Effect of grain size on the yield stress.Effect of grain size on the general shape of the stress-strain curve at low strains. A parametric study shows the model to be quite robust but that it is particularly sensitive to the value of the exponent assumed for the twin nucleation rate law. It is seen that preventing the formation of interaction twins provides an important avenue for hardening and that the flow stress is also particularly sensitive to the relaxation of the twin back stresses. The model shows the importance of taking microstructure into account when modelling twinning.

Relative abundance of full-length and truncated FOXP1 isoforms is associated with differential NFκB activity in Follicular Lymphoma

FOXP1 is a transcriptional repressor that has been proposed to repress the expression of some NFκB-responsive genes. Furthermore, truncated forms of FOXP1 have been associated with a subtype of Diffuse Large B-cell Lymphoma characterised by constitutive NFκB activity, indicating that they may inhibit this repression. We have shown that FL tumors have increased relative abundance of truncated FOXP1 isoforms and this is associated with increased expression of NFκB-associated genes. Our results provide strong evidence that relative FOXP1 isoform abundance is associated with NFκB activity in FL, and could potentially be used as a marker for this gene signature.

On dilatational plastic constitutive equation of ductile materials and plastic loading paths at bifurcation

The dilatational plastic constitutive equation presented in this paper is proved to be in a form of generality. Based on this equation, the constitutive behaviour of materials at the moment of bifurcation is demonstrated to follow a loading path with the response as "soft" as possible.

Bullying as a social process : factors influencing bystander behaviour

Bullying was approached as a social phenomenon in the present study. The central aim of this thesis was to uncover some of the factors that contribute to the attitudes and behavioural choices of bystanders during bullying situations. With this type of information, interventions can be tailored to change the behaviour of bystanders during bullying situations, and thus the ethos of the larger group. Thus, acting to alter the available sources of reinforcement for bullying behaviour and peer intervention attempts. Six hundred and twenty-six students participated. Students were sampled from grades 4 (n=140), 5 (n=l 13), 7 (n=205), and 8 (n=168). Students were measured for their involvement in bullying and victimization, as well as for involvement in the following bystander behaviours: encouraging, onlooking, defending, and seeking adult support. In addition, students were measured for tolerance of deviance, pro-victim attitudes, social anxiety and fear, and self-efficacy for peer intervention. Last, students were asked to complete a series of qualitative measures, including a series of hypothetical vignettes and open-ended questions. Analyses centered on the following areas: 1) rates of bullying, victimization, and bystander behaviour; 2) the influence of age and gender on bystander behaviour; 3) the characteristics associated with students who predominantly report involvement with defending, seeking adult assistance, encouraging, and onlooking behaviour; and 4) the influence of past involvement with bullying and victimization on bystander behaviour. b .--' -i . k Rates of bullying, victimization, and bystander behaviour were comparable to findings in the existing literature, where male students were more likely than female students to report involvement in both bullying and victimization. Boys were more likely than girls to report participation in encouraging and onlooking behaviours, while being less likely to report involvement in defending and seeking adult assistance. Partly consistent with existing findings, older students were more likely to report involvement in bullying, encouraging, and onlooking behaviour than younger students, who were more likely to report victimization, defending, and seeking adult assistance. Self-identified encouragers and onlookers reported a similar array of characteristics, in that they tended express high levels of tolerance of deviance, while expressing low levels of pro-victim attitudes and self-efficacy for peer intervention. Likewise, self-identified defenders and seekers of adult assistance tended to report a similar array of characteristics to each other, in that they tended to report low levels of tolerance of deviance, while expressing high levels of pro-victim attitudes and self efficacy for peer intervention. Additionally, self-identified bullies and self-identified bully-victims tended to report increased involvement in encouraging and onlooking, whereas self-identified victims tended to report increased involvement in defending behaviour and seeking adult assistance. Results are discussed in terms of implications for bullying prevention and intervention. Specifically, evidence from the present study suggests that as bystanders, students predominantly act to either support bullying acts or to support the victims of these acts, or alternatively, to actively remain outside bullying situations. Thus, encouraging students to make small changes in the way they express these sentiments during bullying situations would act to alter the culture of the larger peer group and the sources of reinforcement available for bullying acts as well as peer intervention attempts.

Dysregulated CD40-NF-kappaB signaling in the pathophysiology of aggressive non -Hodgkin's lymphoma B cells

Non-Hodgkin's Lymphomas (NHL) are a group (>30) of important human lymphoid cancers that unlike other tumors today, are showing a marked increase in incidence. The lack of insight to the pathogenesis of B-cell NHL poses a significant problem in the early detection and effective treatment of these malignancies. This study shows that large B-cell lymphoma (LBCL) cells, the most common type of B-cell NHL (account for more than 30% of cases), have developed a novel mechanism for autonomous neoplastic B cell growth. We have identified that the key transcription factor NF-κB, is constitutively activated in LBCL cell lines and primary biopsy-derived LBCL cells, suggesting that they are autonomously activated, and do not require accessory T-cell signaling for cell growth and survival. Further studies have indicated that LBCL cells ectopically express an important T-cell associated co-mitogenic factor, CD154 (CD40 ligand), that is able to internally activate the CD401NF-κB pathway, through constitutive binding to its cognate receptor, CD40, on the lymphoma cell surface. CD40 activation triggers the formation of a “Signalosome” comprising virtually the entire canonical CD40/NF-κB signaling pathway that is anchored by CD40 in plasma membrane lipid rafts. The CD40 Signalosome is vulnerable to interdiction by antibody against CD40 that disrupts the Signalosome and induces cell death in the malignant cells. In addition to constitutive NF-κB activation, we have found that the nuclear factor of activated T cells (NFAT) transcription factor is also constitutively activated in LBCL cells. We have demonstrated that the constitutively active NFATc1 and c-rel members of the NFAT and NF-κB families of transcription factors, respectively, interact with each other, bind to the CD154 promoter, and synergistically activate CD154 gene transcription. Down-regulation of NFATc1 and c-rel with small interfering RNA inhibits CD154 gene transcription and lymphoma cell growth. Our findings suggest that continuous CD40 activation not only provides dysregulated proliferative stimuli for lymphoma cell growth and extended tumor cell survival, but also allows continuous regeneration of the CD40 ligand in the lymphoma cell and thereby recharges the system through a positive feedback mechanism. Targeting the CD40/NF-κB signaling pathway could provide potential therapeutic modalities for LBCL cells in the future. ^

A short segment within the cytoplasmic domain of the neural cell adhesion molecule (N-CAM) is essential for N-CAM-induced NF-κB activity in astrocytes

The neural cell adhesion molecule (N-CAM) is expressed on the surface of astrocytes, where its homophilic binding leads to the activation of the transcription factor NF-κB. Transfection of astrocytes with a construct encompassing the transmembrane region and the cytoplasmic domain of N-CAM (designated Tm-Cyto, amino acids 685–839 in the full-length molecule) inhibited this activation up to 40%, and inhibited N-CAM-induced translocation of NF-κB to the nucleus. N-CAM also activated NF-κB in astrocytes from N-CAM knockout mice, presumably through binding to a heterophile. This activation, however, was not blocked by Tm-Cyto expression, indicating that the inhibitory effect of the Tm-Cyto construct is specific for cell surface N-CAM. Deletions and point mutations of the cytoplasmic portion of the Tm-Cyto construct indicated that the region between amino acids 780 and 800 were essential for inhibitory activity. This region contains four threonines (788, 793, 794, and 797). Mutation to alanine of T788, T794, or T797, but not T793, abolished inhibitory activity, as did mutation of T788 or T797 to aspartic acid. A Tm-Cyto construct with T794 mutated to aspartic acid retained inhibitory activity but did not itself induce a constitutive NF-κB response. This result suggests that phosphorylation of T794 may be necessary but is not the triggering event. Overall, these findings define a short segment of the N-CAM cytoplasmic domain that is critical for N-CAM-induced activation of NF-κB and may be important in other N-CAM-mediated signaling.

The relationship between transformational leadership and innovative behaviour in a healthcare context:a team learning versus a cohesion perspective

The purpose of this study was to explore whether the relationship between transformational leadership and innovative behaviour is explained via the mediating role of team learning, or whether instead team cohesion mediates this relationship. Using survey data from 158 professionals within 21 teams in the Dutch healthcare context, we tested by means of hierarchical regression analyses: (a) the relationship between transformational leadership and innovative behaviour; (b) whether team learning or cohesion mediates this relationship; and (c) the relationship between team learning and cohesion, in relation to transformational leadership. Results showed that transformational leadership is positively related to innovative behaviour and that both cohesion and team learning mediate this relationship, with team learning being the strongest mediator. Addressing a neglected area, our study provides evidence to show that managers who enhance team learning are likely to maximise employees' scope for engaging in innovative behaviours. © 2012 Inderscience Enterprises Ltd.

Deformation with coupled chemical diffusion

The deformation of rocks is commonly intimately associated with metamorphic reactions. This paper is a step towards understanding the behaviour of fully coupled, deforming, chemically reacting systems by considering a simple example of the problem comprising a single layer system with elastic-power law viscous constitutive behaviour where the deformation is controlled by the diffusion of a single chemical component that is produced during a metamorphic reaction. Analysis of the problem using the principles of non-equilibrium thermodynamics allows the energy dissipated by the chemical reaction-diffusion processes to be coupled with the energy dissipated during deformation of the layers. This leads to strain-rate softening behaviour and the resultant development of localised deformation which in turn nucleates buckles in the layer. All such diffusion processes, in leading to Herring-Nabarro, Coble or “pressure solution” behaviour, are capable of producing mechanical weakening through the development of a “chemical viscosity”, with the potential for instability in the deformation. For geologically realistic strain rates these chemical feed-back instabilities occur at the centimetre to micron scales, and so produce structures at these scales, as opposed to thermal feed-back instabilities that become important at the 100–1000 m scales.

An exploration into younger and older pedestrians' risky behaviours at train level crossings

Background: Younger and older pedestrians are both overrepresented in train-pedestrian injury and fatality collision databases. However, scant research has attempted to determine the factors that influence level crossing behaviours for these high risk groups. Method: Five focus groups were undertaken with a total of 27 younger and 17 older pedestrian level crossing users (N = 44). Due to the lack of research in the area, a focus group methodology was implemented to gain a deeper exploratory understanding into the sample’s decision making processes through a pilot study. The three main areas of enquiry were identifying the: (a) primary reasons for unsafe behaviour; (b) factors that deter this behaviour and (c) proposed interventions to improve pedestrian safety at level crossings in the future. Results: Common themes to emerge from both groups regarding the origins of unsafe behaviours were: running late and a fatalistic perspective that some accidents are inevitable. However, younger pedestrians were more likely to report motivators to be: (a) non-perception of danger; (b) impulsive risk taking; and (c) inattention. In contrast, older pedestrians reported their decisions to cross are influenced by mobility issues and sensory salience. Conclusion: The findings indicate that a range of factors influence pedestrian crossing behaviours. This paper will further outline the major findings of the research in regards to intervention development and future research direction.

What consumers think, do and say about antibiotic use

Objective The objectives of this study were to investigate (1) the attitudes and behaviours of Australian consumers in antibiotic use, and (2) their understanding of antibiotic resistance. Methods Semi-structured interviews were conducted with consumers in May/June 2015. Convenience sampling was used to recruit consumers between 18–54 years old. Thirty-two consumers were interviewed. Transcripts were analysed to identify themes. Lessons Learned Dominant themes for attitudes and behaviours regarding antibiotics were (a) avoidance of antibiotic use unless clinically warranted; (b) antibiotics were useful but “weakened the body”; and (c) use of complementary medicines as adjuncts to antibiotics or to strengthen the immune system. Key information needs were (a) unambiguous instructions from GPs when prescribed antibiotics, to avoid inappropriate medicine-taking behaviour; (b) rationale for antibiotic selection; and (c) treatment duration. Antibiotic resistance was conceptualised in three ways: as a property of the body (body becomes resistant to antibiotics); the medication (antibiotic no longer effective); and the bacteria (bacteria is resistant). Antibiotic resistance was perceived as an issue that would only affect the wider community in the future, although most recognised that it is a current challenge for hospitals. Personal good health and/or avoidance of antibiotics were perceived as insurance against being adversely affected by antibiotic resistance. Implications A structured survey (discrete choice experiment) will be developed from these findings to investigate how consumers trade-off on factors influencing antibiotic use. Public health campaigns promoting conservation of antibiotics can benefit from these findings.

Processing maps for hot working of Cu-Ni-Zn alloys. Part I - Alpha-nickel silver

The constitutive behaviour of agr — nickel silver in the temperature range 700–950 °C and strain rate range 0.001–100 s–1 was characterized with the help of a processing map generated on the basis of the principles of the ldquodynamic materials modelrdquo of Prasadet al Using the flow stress data, processing maps showing the variation of the efficiency of power dissipation (given by 2m/(m+1) wherem is the strain-rate sensitivity) with temperature and strain rate were obtained, agr-nickel silver exhibits a single domain at temperatures greater than 750 °C and at strain rates lower than 1s–1, with a maximum efficiency of 38% occurring at about 950 °C and at a strain rate of 0.1 s–1. In the domain the material undergoes dynamic recrystallization (DRX). On the basis of a model, it is shown that the DRX is controlled by the rate of interface formation (nucleation) which depends on the diffusion-controlled process of thermal recovery by climb. At high strain rates (10 and 100s–1) the material undergoes microstructural instabilities, the manifestations of which are in the form of adiabatic shear bands and strain markings.