Edith Cowan University

About: Edith Cowan University is a education organization based out in Perth, Western Australia, Australia. It is known for research contribution in the topics: Population & Context (language use). The organization has 4040 authors who have published 13529 publications receiving 339582 citations. The organization is also known as: Edith Cowan & ECU.

Influence of running velocity on vertical, leg and joint stiffness : modelling and recommendations for future research.

Abstract: Human running can be modelled as either a spring-mass model or multiple springs in series. A force is required to stretch or compress the spring, and thus stiffness, the variable of interest in this paper, can be calculated from the ratio of this force to the change in spring length. Given the link between force and length change, muscle stiffness and mechanical stiffness have been areas of interest to researchers, clinicians, and strength and conditioning practitioners for many years. This review focuses on mechanical stiffness, and in particular, vertical, leg and joint stiffness, since these are the only stiffness types that have been directly calculated during human running. It has been established that as running velocity increases from slow-to-moderate values, leg stiffness remains constant while both vertical stiffness and joint stiffness increase. However, no studies have calculated vertical, leg or joint stiffness over a range of slow-to-moderate values to maximum values in an athletic population. Therefore, the effects of faster running velocities on stiffness are relatively unexplored. Furthermore, no experimental research has examined the effects of training on vertical, leg or joint stiffness and the subsequent effects on running performance. Various methods of training (Olympic style weightlifting, heavy resistance training, plyometrics, eccentric strength training) have shown to be effective at improving running performance. However, the effects of these training methods on vertical, leg and joint stiffness are unknown. As a result, the true importance of stiffness to running performance remains unexplored, and the best practice for changing stiffness to optimize running performance is speculative at best. It is our hope that a better understanding of stiffness, and the influence of running speed on stiffness, will lead to greater interest and an increase in experimental research in this area.

Genome analysis of Clostridium difficile PCR ribotype 014 lineage in australian pigs and humans reveals a diverse genetic repertoire and signatures of long-range interspecies transmission

Abstract: Clostridium difficile PCR ribotype (RT) 014 is well established in both human and porcine populations in Australia, raising the possibility that C. difficile infection (CDI) may have a zoonotic or foodborne aetiology. Here, whole genome sequencing and high-resolution core genome phylogenetics were performed on a contemporaneous collection of 40 Australian RT014 isolates of human and porcine origin. Phylogenies based on MLST (7 loci, STs 2, 13 and 49) and core orthologous genes (1,260 loci) showed clustering of human and porcine strains indicative of very recent shared ancestry. Core genome single nucleotide variant (SNV) analysis found 42% of human strains showed a clonal relationship (separated by ≤ 2 SNVs in their core genome) with one or more porcine strains, consistent with recent inter-host transmission. Clones were spread over a vast geographic area with 50% of the human cases occurring without recent healthcare exposure. These findings suggest a persistent community reservoir with long-range dissemination, potentially due to agricultural recycling of piggery effluent. We also provide the first pan-genome analysis for this lineage, characterising its resistome, prophage content and in silico virulence potential. The RT014 is defined by a large ‘open’ pan-genome (7,587 genes) comprising a core genome of 2,296 genes (30.3% of the total gene repertoire) and an accessory genome of 5,291 genes. Antimicrobial resistance genotypes and phenotypes varied across host populations and ST lineages and were characterised by resistance to tetracycline (tetM, tetA(P), tetB(P) and tetW), clindamycin/erythromycin (ermB) and aminoglycosides (aph3-III-Sat4A-ant6-Ia). Resistance was mediated by clinically important mobile genetic elements, most notably Tn6194 (harbouring ermB) and a novel variant of Tn5397 (harbouring tetM). Numerous clinically important prophages (Siphoviridae and Myoviridae) were identified as well as an uncommon accessory gene regulator locus (agr3). Conservation in the pathogenicity locus and S-layer correlated with ST affiliation, further extending the concept of clonal C. difficile lineages. This study provides novel insights on the genetic variability and strain relatedness of C. difficile RT014, a lineage of emerging One Health importance. Ongoing molecular and genomic surveillance of strains in humans, animals, food and the environment is imperative to identify opportunities to reduce the overall CDI burden.

Inequality matters: Classroom status hierarchy and adolescents' bullying

Abstract: The natural emergence of status hierarchies in adolescent peer groups has long been assumed to help prevent future intragroup aggression. However, clear evidence of this beneficial influence is lacking. In fact, few studies have examined between-group differences in the degree of status hierarchy (defined as within-group variation in individual status) and how they are related to bullying, a widespread form of aggression in schools. Data from 11,296 eighth- and ninth-graders (mean age = 14.57, 50.6 % female) from 583 classes in 71 schools were used to determine the direction of the association between classroom degree of status hierarchy and bullying behaviors, and to investigate prospective relationships between these two variables over a 6-month period. Multilevel structural equation modeling analyses showed that higher levels of classroom status hierarchy were concurrently associated with higher levels of bullying at the end of the school year. Higher hierarchy in the middle of the school year predicted higher bullying later in the year. No evidence was found to indicate that initial bullying predicted future hierarchy. These findings highlight the importance of a shared balance of power in the classroom for the prevention of bullying among adolescents.

Constituting the Feminist Subject in Poststructuralist Discourse

Abstract: In this article, we describe a collective biography that we convened in order to revisit the site of the radical theoretical break with the liberal humanist individual marked by the poststructuralist work of Henriques and colleagues and the feminist poststructuralist work of Weedon. These writers suggest that the new subject of poststructuralist theory will be more open to the changes desired by feminist and social justice movements. They describe the break with the liberal humanist subject as a break that heralds new possibilities of personal and cultural transformation. In this article, using the medium of collective biography stories, we revisit the relation between the liberal humanist individual and the transformative possibilities poststructuralist writers envisaged for the new subject of poststructuralism. We situate the discussion in the context of our transformation into neoliberal subjects over the last three decades.

Detached kelps from distant sources are a food subsidy for sea urchins

Abstract: Trophic subsidies link habitats and can determine community structure in the subsidised habitats. Knowledge of the spatial extents of trophic interactions is important for understanding food webs, and for making spatial management practices more efficient. We demonstrate trophic linkages between detached (drift) fragments of the kelp Ecklonia radiata and the purple sea urchin Heliocidaris erythrogramma among discrete rocky reefs separated by kilometres. Sea urchins were abundant at one inshore reef, where the biomass of drift was usually high. There, sea urchins trapped detached kelp at high rates, although local kelp abundance was low. Most detached kelp present on the reef was retained by sea urchins. Detached seagrass, which was abundant on the reef, was not retained by sea urchins in large quantities. Experiments with tethered pieces of kelp showed that sea urchins only consumed detached fragments, and did not consume attached kelps. Comparisons of the morphology of detached fragments of kelp collected from the inshore reef to attached kelps from reefs further offshore showed that a large proportion (30–95%, varying among dates) of the fragments originated at distant reefs (≥2 km away). At the inshore reef, the sea urchin H. erythrogramma is subsidised by detached kelps, and detached kelp fragments have been transported across landscapes. Cross-habitat resource subsidies therefore link discrete reef habitats separated by kilometres of non-reef habitat.