Microstructures, mechanical properties and in vitro corrosion behaviour of biodegradable Mg-Zr-Ca alloys

The microstructures, mechanical properties, corrosion behaviour and biocompatibility of the Mg-Zr-Ca alloys have been investigated for potential use in orthopaedic applications. The microstructures of the alloys were examined using X-ray diffraction analysis, optical microscopy and scanning electron microscopy. The mechanical properties of Mg-Zr-Ca alloys were determined from compressive tests. The corrosion behaviour has been investigated using an immersion test and electrochemical measurement. The biocompatibility was evaluated by cell growth factor using osteoblast-like SaOS2 cell. The experimental results indicate that the hot-rolled Mg-Zr-Ca alloys exhibit much finer microstructures than the as-cast Mg-Zr-Ca alloys which show coarse microstructures. The compressive strength of the hot-rolled alloys is much higher than that of the as-cast alloys and the human bone, which would offer appropriate mechanical properties for orthopaedic applications. The corrosion resistance of the alloys can be enhanced significantly by hot-rolling process. Hot-rolled Mg-0.5Zr-1Ca alloy (wt %) exhibits the lowest corrosion rate among all alloys studied in this paper. The hot-rolled Mg-0.5Zr-1Ca and Mg-1Zr-1Ca alloys exhibit better biocompatibility than other studied alloys and possess advanced mechanical properties, corrosion resistance and biocompatibility, suggesting that they have a great potential to be good candidates for orthopaedic applications. © 2012 Springer Science+Business Media New York.

Setback distances as a conservation tool in wildlife-human interactions : testing their efficacy for birds affected by vehicles on open-coast sandy beaches

In some wilderness areas, wildlife encounter vehicles disrupt their behaviour and habitat use. Changing driver behaviour has been proposed where bans on vehicle use are politically unpalatable, but the efficacy of vehicle setbacks and reduced speeds remains largely untested. We characterised bird-vehicle encounters in terms of driver behaviour and the disturbance caused to birds, and tested whether spatial buffers or lower speeds reduced bird escape responses on open beaches. Focal observations showed that: i) most drivers did not create sizeable buffers between their vehicles and birds; ii) bird disturbance was frequent; and iii) predictors of probability of flushing (escape) were setback distance and vehicle type (buses flushed birds at higher rates than cars). Experiments demonstrated that substantial reductions in bird escape responses required buffers to be wide (> 25 m) and vehicle speeds to be slow (< 30 km h-1). Setback distances can reduce impacts on wildlife, provided that they are carefully designed and derived from empirical evidence. No speed or distance combination we tested, however, eliminated bird responses. Thus, while buffers reduce response rates, they are likely to be much less effective than vehicle-free zones (i.e. beach closures), and rely on changes to current driver behaviour

Contextually Learnt Detection of Unusual Motion-Based Behaviour in Crowded Public Spaces

In this paper we are interested in analyzing behaviour in crowded publicplaces at the level of holistic motion. Our aim is to learn, without user input, strong scene priors or labelled data, the scope of ‘‘normal behaviour’’ for a particular scene and thus alert to novelty in unseen footage. The first contribution is a low-level motion model based on what we term tracklet primitives, which are scenespecific elementary motions. We propose a clustering-based algorithm for tracklet estimation from local approximations to tracks of appearance features. This is followed by two methods for motion novelty inference from tracklet primitives: (a) an approach based on a non-hierarchial ensemble of Markov chains as a means of capturing behavioural characteristics at different scales, and (b) a more flexible alternative which exhibits a higher generalizing power by accounting for constraints introduced by intentionality and goal-oriented planning of human motion in a particular scene. Evaluated on a 2 h long video of a busy city marketplace, both algorithms are shown to be successful at inferring unusual behaviour, the latter model achieving better performance for novelties at a larger spatial scale.

Doxycycline-inducible expression of SPARC/osteonectin/BM40 in MDA-MB-231 human breast cancer cells results in growth inhibition

SPARC (secreted protein acidic and rich in cysteine)/BM40/Osteonectin is a matricellular protein with multiple effects on cell behaviour. In vitro, its major known functions are anti-adhesive and anti-proliferative, and it is associated with tissue remodelling and cancer in vivo. SPARC is overexpressed in many cancers, including breast cancer, and the effects of SPARC seem to be cell type-specific. To study the effects of SPARC on breast cancer, we transfected SPARC into the MDA-MB-231 BAG, human breast cancer cell line using the Tet-On inducible system. By western analysis, we found low background levels in the MDA-MB-231 BAG and clone X parental cells, and prominent induction of SPARC protein expression after doxycycline treatment in SPARC transfected clones X5, X21, X24 and X75. Induction of SPARC expression did not affect cell morphology or adhesiveness to collagens type I and IV, but it slowed the rate of proliferation in adherent cultures. Cell cycle analysis showed that SPARC slowed the progression to S phase. Doxycycline induction of SPARC also slowed the rate of monolayer wound closure in the cultured wound healing assay. Thymidine inhibition of proliferation abrogated this effect, confirming that it was due to anti-proliferation rather than inhibition of migration. Consistent with this, we were unable to detect any differences in migration and Matrigel outgrowth analysis of doxycycline-stimulated cells. We conclude that SPARC is inhibitory to human breast cancer cell proliferation, and does not stimulate migration, in contrast to its stimulatory effects reported for melanoma (proliferation and migration) and glioma (migration) cells. Similar growth repression by SPARC has been reported for ovarian cancer cells, and this may be a common feature among carcinoma.

Associations of parental rules and socioeconomic position with preschool children's sedentary behaviour and screen time

There is little current understanding of the influences on sedentary behaviour and screen time in preschool children. This study investigated socioeconomic position (SEP) and parental rules as potential correlates of preschool children's sedentary behaviour and screen time.

Employee engagement, human resource management practices and competitive advantage

Abstract
Purpose - The purpose of this paper is to argue in support of a model that shows how four key HRM practices focused on engagement influence organizational climate, job demands and job resources, the psychological experiences of safety, meaningfulness and availability at work, employee engagement, and individual, group and organizational performance and competitive advantage.
Design/methodology/approach - This conceptual review focuses on the research evidence showing interrelationships between organizational context factors, job factors, individual employee psychological and motivational factors, employee outcomes, organizational outcomes and competitive advantage. The proposed model integrates frameworks that have previously run independently in the HR and engagement literatures.
Findings - The authors conclude that HRM practitioners need to move beyond the routine administration of annual engagement surveys and need to embed engagement in HRM policies and practices such personnel selection, socialization, performance management, and training and development.
Practical implications - The authors offer organizations clear guidelines for how HR practices (i.e. selection, socialization, performance management, training) can be used to facilitate and improve employee engagement and result in positive outcomes that will help organizations achieve a competitive advantage.
Originality/value - The authors provide useful new insights for researchers and management professionals wishing to embed engagement within the fabric of HRM policies and practices and employee behaviour, and organizational outcomes.

Responding to human full-body gestures embedded in motion data streams.

 This research created a neural-network enabled artificially intelligent performing agent that was able to learn to dance and recognise movement through a rehearsal and performance process with a human dancer. The agent exhibited emergent dance behaviour and successfully engaged in a live, semi-improvised dance performance with the human dancer.

Driver behaviour prediction for motion simulators using changepoint segmentation

Driving phenomenon is a repetitive process, that permits sequential learning under identifying the proper change periods. Sequential filtering is widely used for tracking and prediction of state dynamics. However, it suffers at abrupt changes, which cause sudden incremental prediction error. We provide a sequential filtering approach using online Bayesian detection of change points to decrease prediction error generally, and specifically at abrupt changes. The approach learns from optimally detected segments for identifying driving behaviour. Change points detection is done by the Pruned Exact Linear Time algorithm. Computational cost of our approach is bounded by the cost of the implemented sequential filter. This computational performance is suitable to the online nature of motion simulator's delay reduction. The approach was tested on a simulated driving scenario using Vortex by CM Labs. The state dimensions are simulated 2D space coordinates, and velocity. Particle filter was used for online sequential filtering. Prediction results show that change-point detection improves the quality of state estimation compared to traditional sequential filters, and is more suitable for predicting behavioural activities.

Emergent behaviour: learning from an artificially intelligent performing software agent

This research investigates the possibility for emergent choreographic behaviour to arise from the interactions between a human dancer and a learning, digital performing agent. The cognitive framework is extended through theories of distributed cognition to take into account the two interacting agents rather than a single agent and its environment. The Artificial Neural Network based performing agent demonstrated emergent dance behaviour when performing live with the human dancer. The agent was able to follow the dancer, create movement phrases based on what the dancer was performing and recognize short movement phrases, as a result of the interaction of the dancer’s motion captured movement data and the agent’s artificial neural network. This emergent behaviour was not explicitly programmed, but emerged as a result of the learning process and the interactions with the human dancer.

An application of an extended effort-reward imbalance model to police absenteeism behaviour

Purpose – Frequent absences from work can be highly disruptive, whilst also potentially indicating problematic working conditions that can lead to increased withdrawal behaviour. The purpose of this paper is to test the predictive capability of an expanded effort-reward imbalance model on employee absenteeism within the context of policing.

Design/methodology/approach – Three separate reward systems are identified by the effort-reward imbalance model. In this study, the authors assessed these individual components for their contribution to officer withdrawal behaviour in the form of absenteeism frequency. Data were gathered from a sample of operational officers (n=553) within a large Australian police agency.

Findings – Findings indicate that there was a strong influence of social rewards such as social support and recognition in the workplace on officer absenteeism rates. Low workload was associated with a higher frequency of absenteeism suggesting a potential underloading effect. There were a number of significant interactions providing support for the effort-reward imbalance mechanism and the separation of the reward construct. Security rewards were particularly influential and significantly moderated the relationship between effort and absenteeism.

Research limitations/implications – Differential effects of occupational rewards were identified in the study, indicating that there are significant opportunities for expansion of the effort-reward imbalance model along with opportunities for HRM practitioners in terms of employee recognition and remuneration programmes. This research was focused on a specific sample of operational officers, therefore should be expanded to include multiple occupational groups.

Originality/value – This paper considers and expanded model of worker strain and contributes a longitudinal assessment of the association between perceived effort and reward systems and worker absenteeism.

Detection of anomalous crowd behaviour using hyperspherical clustering

Analysis of crowd behaviour in public places is an indispensable tool for video surveillance. Automated detection of anomalous crowd behaviour is a critical problem with the increase in human population. Anomalous events may include a person loitering about a place for unusual amounts of time; people running and causing panic; the size of a group of people growing over time etc. In this work, to detect anomalous events and objects, two types of feature coding has been proposed: spatial features and spatio-temporal features. Spatial features comprises of contrast, correlation, energy and homogeneity, which are derived from Gray Level Co-occurrence Matrix (GLCM). Spatio-temporal feature includes the time spent by an object at different locations in the scene. Hyperspherical clustering has been employed to detect the anomalies. Spatial features revealed the anomalous frames by using contrast and homogeneity measures. Loitering behaviour of the people were detected as anomalous objects using the spatio-temporal coding.

Criminalising controlling and coercive behaviour: the next step in the prosecution of family violence?

A new offence of controlling or coercive behaviour in intimate or family relationships has recently come into force in England. The parliament of Scotland is contemplating introducing a related offence. The offence is distinctive because it criminalises conduct – controlling and coercive behaviour – which has specified negative behavioural and psychological consequences without necessarily requiring that a victim sustain physical injury or fear death or serious harm. This significant extension of the criminal law supplements anti-stalking legislation and has been justified on the basis that it addresses a core feature of abusive relationships, is essential to protect the human rights of victims of domestic abuse, and has community support. In the context of the ongoing debate about how best to tackle the problem of domestic abuse in Australia, this development provides an innovative – albeit still untested – model and should be closely examined.

The disparity between human rights policy and parliamentary practice in Australia : a Victorian case study

Over the past decade alcohol-related violence in and around licensed premises has given rise to significant legislative, regulatory and operational policing developments. In Australia, the State of Victoria introduced police-imposed banning notices as part of a range of provisions and new powers targeting alcohol-related disorderly behaviour. Banning notices exemplify a broader shift towards discretionary, pre-emptive, regulatory, summary justice which circumvents the criminal law, dilutes individual rights, and reconfigures expectations of balance in the administration of justice. The legal principles upon which banning notices are based and the way in which they were enacted by the Victorian Parliament challenge both the purpose and specific requirements of Victoria’s Charter of Human Rights and Responsibilities Act 2006. Detailed analysis of the application of the Charter compliance processes to the banning notice provisions point to a notable disparity between the expectations of formal human rights policy and the reality of substantive practice. The broader effect of such a disconnect is potentially significant, but has been largely opaque to meaningful scrutiny.