Contribution of stretch to the change of activation properties of muscle fibers in the diaphragm at the transition from fetal to neonatal life

The transition from fetal to postnatal life involves clearance of liquid from the lung and airways, and rapid formation of a functional residual capacity. Despite the importance of the diaphragm in this process, the impact of birth on the mechanical and functional activity of its muscle fibers is not known. This study determined the contractile characteristics of individual “skinned” diaphragm fibers from 70 days (0.47) gestation to after birth in sheep. Based on differential sensitivity to the divalent ions calcium (Ca²⁺) and strontium (Sr²⁺), all fibers in the fetal diaphragm were classified as “fast,” whereas fibers from the adult sheep diaphragm exhibited a “hybrid” phenotype where both “fast” and “slow” characteristics were present within each single fiber. Transition to the hybrid phenotype occurred at birth, was evident after only 40 min of spontaneous breathing, and could be induced by simple mechanical stretch of diaphragm fibers from near-term fetuses (∼147 days gestation). Both physical stretch of isolated fibers, and mechanical ventilation of the fetal diaphragm in situ, significantly increased sensitivity to Ca²⁺ and Sr²⁺, maximum force generating capacity, and decreased passive tension in near-term and preterm fetuses; however, only fibers from near-term fetuses showed a complete transition to a “hybrid” activation profile. These findings suggest that stretch associated with the transition from a liquid to air-filled lung at birth induces physical changes of proteins determining the activation and elastic properties of the diaphragm. These changes may allow the diaphragm to meet the increased mechanical demands of breathing immediately after birth.

The langauge of tourism : perfecting soft skills in a flat world

India is Australia's 11th-biggest inbound tourism market, bringing in 148,200 visitors who spent $867 million last year, but by 2020 officials say that could reach 300,000 visitors spending $2.3 billion.
Delhi and Mumbai have been targeted by Australia because they have an emerging middle class and India's highest concentration of affluent households.
The Minister for Tourism, Martin Ferguson, unveiled an India 2020 strategic plan last month at the annual Australian Tourism Exchange in Perth, the largest travel trade show in the southern hemisphere. "We have put a huge effort into attracting tourists from China recently and the next cab off the rank is India," he said.
The plan means that Tourism Australia's "There's Nothing Like Australia" campaign will be rolled out in Delhi and Mumbai and there will be extensive advertising on TV and digital channels as well as print.

A case study of ground response due to diaphragm wall installation

The purpose of this research is to investigate the ground response due to diaphragm wall construction using three-dimensional numerical modelling. In this study, the commercial finite difference method software, FLAC3D, and the finite element upper and lower bound limit analysis methods are employed. In addition, a range of factors are investigated. They include the dimensions of the single panel, overconsolidation ration (OCR), soil stiffness (E/su), and the height of the bentonite slurry. The solutions from the numerical upper bound limit analysis method are used for comparison purposes. The results obtained indicate that the above factors do have influence on ground response in terms of its stability and displacements. The discussion in the paper can be utilised as the reference for practical designs.

Synchronous Objects for One Flat Thing, reproduced

Synchronous Objects is a website where a visitor/ reader can investigate the interlocking systems of organisation in the choreography of William Forsythe's dance One Flat Thing, reproduced (2000). These systems were quantified through the collection of data and transformed into a series of objects - synchronous objects - that work in harmony to explore these choreographic structures, reveal their patterns and re-imagine what they might look like. The goal of the project was to create a learning platform to engage a broad public in this exploration of choreography, to explore cross-disciplinary research and to stimulate creative discovery for specialists and non-specialists alike.

Impossible triangles: flat actors in telematic theatre

In fact, in this scene, both A and B are online. A is in a classroom at the University of Amsterdam in The Netherlands, and B is in a television studio at Deakin University in Melbourne, Australia. The two locations are connected through video conference and, in each space, a local audience watches the local performer in the room, and the remote performer projected on a screen. The performers are captured in profile, and appear to be looking at computer screens in front of them but cannot actually see one another. The text is consciously banal, composed to replicate the broken rhythms and sequences, flattened tone and repetitions of scrolling words in a text box on a screen. Information about presence and absence (A or B is offline or online) is spoken as text. Although the two performers speak in accents that declare their different language/ cultures, the vernacular is generic 'internetslang'. The relatively monotonous and unpunctuated delivery of the textual rhythms is interrupted and counterpointed by a sound lag of nearly a second, and by a faint audio echo as one voice 'lands' in the second location. Its orchestration allows the sound fracture and dispersal in some moments. In other moments, the actors anticipate or absorb the gaps in transmission, driving the speech rhythms through so that the utterance 'arrives' precisely at the end of the prompt line.

Maternal creatine supplementation during pregnancy prevents long-term changes in diaphragm muscle structure and function after birth asphyxia

Using a model of birth asphyxia, we previously reported significant structural and functional deficits in the diaphragm muscle in spiny mice, deficits that are prevented by supplementing the maternal diet with 5% creatine from mid-pregnancy. The long-term effects of this exposure are unknown. Pregnant spiny mice were fed control or 5% creatine-supplemented diet for the second half of pregnancy, and fetuses were delivered by caesarean section with or without 7.5 min of in-utero asphyxia. Surviving pups were raised by a cross-foster dam until 33±2 days of age when they were euthanized to obtain the diaphragm muscle for ex-vivo study of twitch tension and muscle fatigue, and for structural and enzymatic analyses. Functional analysis of the diaphragm revealed no differences in single twitch contractile parameters between any groups. However, muscle fatigue, induced by stimulation of diaphragm strips with a train of pulses (330 ms train/sec, 40 Hz) for 300 sec, was significantly greater for asphyxia pups compared with controls (p<0.05), and this did not occur in diaphragms of creatine + asphyxia pups. Birth asphyxia resulted in a significant increase in the proportion of glycolytic, fast-twitch fibres and a reduction in oxidative capacity of Type I and IIb fibres in male offspring, as well as reduced cross-sectional area of all muscle fibre types (Type I, IIa, IIb/d) in both males and females at 33 days of age. None of these changes were observed in creatine + asphyxia animals. Thus, the changes in diaphragm fatigue and structure induced by birth asphyxia persist long-term but are prevented by maternal creatine supplementation.