Directional persistence and the optimality of run-and-tumble chemotaxis

E. coli does chemotaxis by performing a biased random walk composed of alternating periods of swimming (runs) and reorientations (tumbles). Tumbles are typically modelled as complete directional randomisations but it is known that in wild type E. coli, successive run directions are actually weakly correlated, with a mean directional difference of ∼63°. We recently presented a model of the evolution of chemotactic swimming strategies in bacteria which is able to quantitatively reproduce the emergence of this correlation. The agreement between model and experiments suggests that directional persistence may serve some function, a hypothesis supported by the results of an earlier model. Here we investigate the effect of persistence on chemotactic efficiency, using a spatial Monte Carlo model of bacterial swimming in a gradient, combined with simulations of natural selection based on chemotactic efficiency. A direct search of the parameter space reveals two attractant gradient regimes, (a) a low-gradient regime, in which efficiency is unaffected by directional persistence and (b) a high-gradient regime, in which persistence can improve chemotactic efficiency. The value of the persistence parameter that maximises this effect corresponds very closely with the value observed experimentally. This result is matched by independent simulations of the evolution of directional memory in a population of model bacteria, which also predict the emergence of persistence in high-gradient conditions. The relationship between optimality and persistence in different environments may reflect a universal property of random-walk foraging algorithms, which must strike a compromise between two competing aims: exploration and exploitation. We also present a new graphical way to generally illustrate the evolution of a particular trait in a population, in terms of variations in an evolvable parameter.

Making the fun stop : youth justice reform in Queensland

In 2013 the newly elected conservative Liberal National Party government instigated amendments to the Youth Justice Act 1992 (Qld). Boot camps replaced court ordered youth justice conferencing. In 2014 there were more drastic changes, including opening the Children’s Court proceedings to the public, permitting publication of identifying information of repeat offenders, removing the principle of ‘detention as a last resort’, facilitating prompt transferral of 17 year olds to adult prisons and instigating new bail offences and mandatory boot camp orders for recidivist motor vehicle offenders in Townsville. This article compares these amendments to the legislative frameworks in other jurisdictions and current social research. It argues that these amendments are out of step with national and international best practice benchmarks for youth justice. Early indications are that Indigenous children are now experiencing increased rates of unsentenced remand. The article argues that the government’s policy initiatives are resulting in negative outcomes and that early and extensive evaluations of these changes are essential.

Now we can “see the forest and the trees too” but there are risks : Camera trapping and privacy law in Australia

The use of camera traps in wildlife management is an increasingly common practice. A phenomenon which is also becoming more common is for such camera traps to unintentionally film individuals engaged in a variety of activities, ranging from the innocent to the nefarious and including lewd or potentially embarrassing behaviour. It is therefore possible for the use of camera traps to accidentally encroach upon the privacy rights of persons who venture into the area of surveillance. In this chapter we describe the legal framework of privacy in Australia and discuss the potential risk of this sleeping tiger for users of camera traps. We also present the results of a survey of camera trap users to assess the frequency of such unintended captures and the nature of activity being filmed before discussing the practical implications of these laws for camera traps users in this country and make recommendations.

Interrogating Creative Theory and Creative Work: Inside the Games Studio

The expansion of creative and cultural industries has provided a rich source for theoretical claims and commentary. Much of this reproduces and extends the idea that autonomy is the defining feature of both enterprises and workers. Drawing on evidence from research into Australian development studios in the global digital games industry, the article interrogates claims concerning autonomy and related issues of insecurity and intensity, skill and specialisation, work–play boundaries, identity and attachments. In seeking to reconnect changes in creative labour to the wider production environment and political economy, an argument is advanced that autonomy is deeply contextual and contested as a dimension of the processes of capturing value for firms and workers.

Modeling and control of a 3500 tonne mining robot

Draglines are extremely large machines that are widely used in open-cut coal mines for overburden stripping. Since 1994 we have been working toward the development of a computer control system capable of automatically driving a dragline for a large portion of its operating cycle. This has necessitated the development and experimental evaluation of sensor systems, machines models, closed-loop control controllers, and an operator interface. This paper describes our steps toward the goal through scale-model and full-scale field experimentation.

"Unruly women and semiotic spaces": Jay Verney's a mortality tale

Written at a time of significant changes for women and for women writers in Queensland, Australia, Jay Verney's A Mortality Tale (1994), privileges women's experiences of place and seeks to redeem the feminine from its entrapment in masculine stories/discourses of self and place. This chapter draws on Julia Kristeva's conceptualisation of the semiotic as a way of reading Verney's witty and reflective re-articulation of phallocentric orderings of spatiality and gender.

Early maternal deprivation reduces prepulse inhibition and impairs spatial learning ability in adulthood: No further effect of post-pubertal chronic corticosterone treatment

Prolonged maternal deprivation leads to long-term alterations in hypothalamic–pituitary–adrenal (HPA) axis activity, disturbances of auditory information processing and neurochemical changes in the adult brain, some of which are similar to that observed in schizophrenia. Here we report the adult behavioural effects of maternal deprivation (12 h on postnatal days 9 and 11) in Wistar rats on paradigms of auditory information processing (prepulse inhibition), sensitivity to dopamimetics (amphetamine-induced hyper-locomotion) and cognition (T-maze delayed alternation and Morris water-maze). In addition, we examined the long-lasting effect of chronic 21-day corticosterone treatment during the post-pubertal period (i.e., postnatal days 56–76) on each of these behavioural paradigms in maternally deprived and control rats. Behavioural testing commenced 2 weeks after the termination of corticosterone treatment. Maternal deprivation led to a significant reduction in PPI and impaired spatial learning ability in adulthood, but did not affect the behavioural response to amphetamine. Post-pubertal chronic corticosterone treatment did not have any major long-lasting effects on any of the behavioural measures in either maternally deprived or control rats. Our findings further support maternal deprivation as an animal model of specific aspects of schizophrenia.

Bangarra Dance Theatre: Copyright law and Indigenous culture

This article considers the artistic and legal practices of Bangarra Dance Theatre in a case study of copyright law management in relation to Indigenous culture. It is grounded in the particular local experience, knowledge and understanding of copyright law displayed by the performing arts company. The first part considers the special relationship between Bangarra Dance Theatre and the Munyarrun Clan. It examines the contractual arrangements developed to recognise communal ownership. The next section examines the role of the artistic director and choreographer. It looks at the founder, Carole Johnson, and her successor, Stephen Page. The third part of the article focuses on the role of the composer, David Page. It examines his ambition to set up a Indigenous recording company, Nikinali. Part 4 focuses upon the role of the artistic designers. It looks at the contributions of artistic designers such as Fiona Foley. Part 5 deals with broadcasts of performances on television, film, and multi-media. Part 6 considers the collaborations of Bangarra Dance Theatre with the Australian Ballet, and the Sydney Organising Committee for the Olympic Games. The conclusion considers how Bangarra Dance Theatre has played a part ina general campaign to increase protection of Indigenous copyright law.

Etapas del cambio en personas inactivas tras un programa de promoción de la actividad física en Atención Primaria

Objetivo El objetivo del estudio fue evaluar las Etapas del cambio en relación con la actividad física y el estado de salud general entre personas que participaron en un Programa de promoción de la actividad física (PPAF) de 12 semanas frente a un grupo control. Diseño Ensayo clínico aleatorizado. Participantes Noventa y ocho personas inactivas de ambos sexos con una edad media de 62,82 años procedentes de 2 centros de Atención Primaria del Distrito Sanitario Costa del Sol. Intervención Un PPAF organizado en grupos y siguiendo los criterios del Colegio Americano de Medicina del Deporte, 2 sesiones semanales de 60 min durante 12 semanas. Mediciones principales La variable principal de resultado fue resistencia al cambio en relación con la actividad física. La variable secundaria fue el estado de salud general (componentes físicos y mentales), determinado con el cuestionario de salud general SF12. Resultados Se encontraron diferencias significativas en las etapas del cambio a favor del grupo experimental (p < 0,05). No se encontraron diferencias estadísticamente significativas entre grupos después de la intervención en el estado general de salud. Conclusión Las etapas del cambio se modificaron en las personas inactivas que realizaron el PPAF en Atención Primaria. Futuros estudios son necesarios para identificar qué factores del entorno de los participantes influyen en la resistencia al cambio de la actividad física. Abstract Objective This study has aimed to evaluate the stages of change in relation to physical activity and overall health status among persons who participated in a 12-week Physical activity promotion program (PAPP) compared to a control group. Design Randomized clinical trial. Participants The study included 98 inactive persons of both sexes with a mean age of 62.82 years from 2 of Primary Care Centers of the Malaga Health Care District. Interventions A PAPP organized in groups according to the American College of Sports Medicine criteria including two weekly sessions of 60 minutes each for 3 months. Main measures The primary outcome was to assess resistance to change in relation to physical activity. The secondary variable was overall health (physical and mental components) determined with the SF12 general health questionnaire. Results Significant differences were found in the stages of change (P<.05). There were no significant differences found in general health status improvement in regards to the initial assessment. Conclusion The stages of change were modified in the inactive persons who carried out the PAPP in Primary Care. Future studies are needed to identify which environmental factors influence the resistance to change in physical activity of the participants.

Linking business goals to process models in semantic business process modeling

Broad knowledge is required when a business process is modeled by a business analyst. We argue that existing Business Process Management methodologies do not consider business goals at the appropriate level. In this paper we present an approach to integrate business goals and business process models. We design a Business Goal Ontology for modeling business goals. Furthermore, we devise a modeling pattern for linking the goals to process models and show how the ontology can be used in query answering. In this way, we integrate the intentional perspective into our business process ontology framework, enriching the process description and enabling new types of business process analysis. © 2008 IEEE.

Integrating customer orientation, employee compensation and performance management: A conceptual framework

Compensation systems are an essential tool to link corporate goals such as customer orientation with individual and organisational performance. While some authors demonstrate the positive effects of incorporating nonfinancial measures into the compensation system empirically, companies have encountered problems after linking pay to customer satisfaction. We argue that reasons for this can be attributed to the measurement of customer satisfaction as well as to the missing link between customer satisfaction and customer retention and profitability in theses cases. Hence, there is a strong need for the development of an holistic reward and performance measurement model enabling an organisation to identify cause-and-effect relationships when linking rewards to nonfinancial performance measures. We present a conceptual framework of a success chain driven reward system that enables organisations to systematically derive a customer-oriented reward strategy. In the context of performance evaluation, we propose to rely on integrated and multidimensional measurement methods.

Attitudes toward unauthorized immigrants, authorized immigrants, and refugees

Rates of human migration are steadily rising and have resulted in significant sociopolitical debates over how to best respond to increasing cultural diversity and changing migration patterns. Research on prejudicial attitudes toward immigrants has focused on the attitudes and beliefs that individuals in the receiving country hold about immigrants. The current study enhances this literature by examining how young adults view authorized and unauthorized immigrants and refugees. Using a between-groups design of 191 undergraduates, we found that participants consistently reported more prejudicial attitudes, greater perceived realistic threats, and greater intergroup anxiety when responding to questions about unauthorized compared with authorized immigrants. Additionally, there were differences in attitudes depending on participants’ generational status, with older-generation participants reporting greater perceived realistic and symbolic threat, prejudice, and anxiety than newer-generation students. In some instances, these effects were moderated by participant race/ethnicity and whether they were evaluating authorized or unauthorized immigrants. Lastly, perceived realistic threat, symbolic threat, and intergroup anxiety were significant predictors of prejudicial attitudes. Overall, participants reported positive attitudes toward refugees and resettlement programs in the United States. These findings have implications for future research and interventions focused on immigration and prejudice toward migrant groups.

Development of a new design expression for the in-plane shear capacity of the partially grouted concrete masonry walls

Partially grouted masonry walls subjected to in-plane shear exhibit a complex behaviour because of the influence of the aspect ratio, the pre-compression, the grouting pattern, the ratios of the horizontal and the vertical reinforcements, the boundary conditions and the characteristics of the constituent materials. The existing in-plane shear expressions for the partially grouted masonry are formulated as sum of strength of three parameters, namely, the masonry, the reinforcement and the axial force. The parameter ‘masonry’ includes the wall aspect ratio and the masonry compressive strength; the aspect ratio of the unreinforced panel inscribed into the grouted cores and bond beams are not considered, although failure is often dominated by these unreinforced masonry panels. This paper describes the dominance of these panels, particularly those that are squat, to the shear capacity of whole of shear walls. Further, the current design formulae are shown highly un-conservative by many researchers; this paper provides a potential reason for this un-conservativeness. It is shown that by including an additional term of the unreinforced panel aspect ratio a rational design formula could be established. This new expression is validated with independent test results reported in the literature – both Australian and overseas; the predictions are shown to be conservative.

The effect of HLA-DR on susceptibility to rheumatoid arthritis is influenced by the associated lymphotoxin α-tumor necrosis factor haplotype

Objective. HLA-DRB1, a major genetic determinant of susceptibility to rheumatoid arthritis (RA), is located within 1,000 kb of the gene encoding tumor necrosis factor (TNF). Because certain HLA-DRB1*04 subtypes increase susceptibility to RA, investigation of the role of the TNF gene is complicated by linkage disequilibrium (LD) between TNF and DRB1 alleles. By adequately controlling for this LD, we aimed to investigate the presence of additional major histocompatibility complex (MHC) susceptibility genes. Methods. We identified 274 HLA-DRB1*04-positive cases of RA and 271 HLA-DRB1*04-positive population controls. Each subject was typed for 6 single-nucleotide polymorphisms within a 4.5-kb region encompassing TNF and lymphotoxin a (LTA). LTA-TNF haplotypes in these unrelated individuals were determined using a combination of family data and the PHASE software program. Results. Significant differences in LTA-TNF haplotype frequencies were observed between different subtypes of HLA-DRB1*04. The LTA-TNF haplotypes observed were very restricted, with only 4 haplotypes constituting 81% of all haplotypes present. Among individuals carrying DRB1*0401, the LTA-TNF 2 haplotype was significantly underrepresented in cases compared with controls (odds ratio 0.5 [95% confidence interval 0.3-0.8], P = 0.007), while in those with DRB1*0404, the opposite effect was observed (P = 0.007). Conclusion. These findings suggest that the MHC contains genetic elements outside the LTA-TNF region that modify the effect of HLA-DRB1 on susceptibility to RA.