161 resultados para Stars: white dwarfs


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The question that has led and organised this special edition on David Bowie draws provocative attention to the way his career has been narrated by the constant transformation and recasting of his star image. By asking who is he now? the edition recognises that Bowie is a chameleon figure, one who reinvents himself in and across the media and art platforms that he is found in. This process of renewal means that Bowie constantly kills himself, an artistic suicide that allows for dramatic event moments to populate his music, and for a rebirth to emerge at the same time or shortly after he expires. Bowie has killed Major Tom, Ziggy Stardust, Halloween Jack, Aladdin Sane, and the Thin White Duke to name but a few of his alter-egos. In this environment of death and resurrection, Bowie becomes a heightened, exaggerated enigma, a figure who constantly seems to be artificial or constructed and yet whose work asks us to look for his real self behind the mask – to ask the question, is this now the real Bowie that faces us? Of course, the answer is always no because Bowie is a contradictory constellation of images, stories and sounds whose star image rests on remaining an enigma, and like all stars in our midst, exists as a representation. Nonetheless, with Bowie - with this hyper- schizophrenic, confessional artist – the fan desire to get to know him, to immerse oneself in his worlds, fantasises, and projections - is particularly acute. With the unexpected release of The Next Day ((Iso/Columbia) on the 8th March 2013, the day of his 66th birthday, Bowie was resurrected again. The album and subsequent music videos drew explicitly on the question of who Bowie was and had been, creating a media frenzy around his past work, fan nostalgia for previous Bowie incarnations, and a pleasurable negotiation with his new output. In this special edition, edited by life-long Bowie fans, with contributions from die-hard Bowie aficionados, we seek to find him in the fragments and remains of what once was, and in the new enchantments of his latest work.

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During the last decade, the striated muscle activator of Rho signaling (STARS), a muscle-specific protein, has been proposed to play an increasingly important role in skeletal muscle growth, metabolism, regeneration and stress adaptation. STARS influences actin dynamics and, as a consequence, regulates the myocardin-related transcription factor A/serum response factor (MRTF-A/SRF) transcriptional program, a well-known pathway controlling skeletal muscle development and function. Muscle-specific stress conditions, such as exercise, positively regulates, while disuse and degenerative muscle diseases are associated with a downregulation of STARS and its downstream partners, suggesting a pivotal role for STARS in skeletal muscle health. This review provides a comprehensive overview of the known role and regulation of STARS and the members of its signaling pathway, RhoA, MRTF-A and SRF, in skeletal muscle.

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In most vertebrate species, glucocorticoid levels and stress sensitivity vary in relation to season and life-history stage. In birds, baseline corticosterone (CORT) and stress sensitivity are typically highest while breeding and decrease substantially during moult. Because elevated CORT adversely affects protein synthesis, moult-related CORT suppression is thought to be necessary for forming high-quality feathers. Surprisingly, some passerine species lack moult-related CORT suppression, but these are distinguished by having slow rates of moult and being opportunistic breeders. We examined baseline and stress-induced CORT levels in an opportunistically breeding Australian passerine, the white-plumed honeyeater (Lichenostomus penicillatus). Although this species has a slower moult rate than high-latitiude breeders, it differs little from north-temperate passerines. Neither baseline nor stress-induced CORT levels varied with season (winter, spring or summer), sex or moult status in adult birds. While breeding tended to be highest in early spring through late summer, laparotomies revealed only limited reduction in testicular size in males the year round. In all but one sampling period, at least some females displayed follicular hierarchy. Breeding usually coincides with outbreaks of phytophagous insects, which can happen at any time of the year. This results in moult/breeding overlap when infestations occur in late spring or summer. The ability of this species to moult and breed at the same time while having breeding-levels of CORT demonstrates that CORT suppression is not a prerequisite for synthesis of high-quality feathers. An experimental design incorporating moulting and non-moulting phenotypes is suggested to test the functional significance of CORT suppression in other species.

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In this paper we examine the phylogeny and biogeography of the temperate genera of the Ophiocomidae (Echinodermata: Ophiuroidea) which have an interesting asymmetrical anti-tropical distribution, with two genera (Ophiocomina and Ophiopteris) previously considered to have a separate species in both the North and South hemispheres, and the third (Clarkcoma) diversifying in the southern Australian/New Zealand region. Our phylogeny, generated from one mitochondrial and two nuclear markers, revealed that Ophiopteris is sister to a mixed Ophiocomina/. Clarkcoma clade. Ophiocomina was polyphyletic, with O. nigra and an undescribed species from the South Atlantic Ocean sister to a clade including Clarkcoma species and O. australis. The phylogeny also revealed a number of recently diverged lineages occurring within Clarkcoma, some of which are considered to be cryptic species due to the similarity in morphology combined with the apparent absence of interbreeding in a sympatric distribution, while the status of others is less certain. The phylogeny provides support for two transequatorial events in the group under study. A molecular clock analysis places both events in the middle to late Miocene. The analysis excludes a tectonic vicariance hypothesis for the antitropical distribution associated with the breakup of Pangaea and also excludes the hypothesis of more recent gene flow associated with Plio/Pleistocene glacial cycling. © 2014 Elsevier Inc.

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The striated muscle activator of Rho signalling (STARS) pathway is suggested to provide a link between external stress responses and transcriptional regulation in muscle. However, the sensitivity of STARS signalling to different mechanical stresses has not been investigated. In a comparative study, we examined the regulation of the STARS signalling pathway in response to unilateral resistance exercise performed as either eccentric (ECC) or concentric (CONC) contractions as well as prolonged training; with and without whey protein supplementation. Skeletal muscle STARS, myocardian-related transcription factor-A (MRTF-A) and serum response factor (SRF) mRNA and protein, as well as muscle cross-sectional area and maximal voluntary contraction, were measured. A single-bout of exercise produced increases in STARS and SRF mRNA and decreases in MRTF-A mRNA with both ECC and CONC exercise, but with an enhanced response occurring following ECC exercise. A 31% increase in STARS protein was observed exclusively after CONC exercise (P < 0.001), while pSRF protein levels increased similarly by 48% with both CONC and ECC exercise (P < 0.001). Prolonged ECC and CONC training equally stimulated muscle hypertrophy and produced increases in MRTF-A protein of 125% and 99%, respectively (P < 0.001). No changes occurred for total SRF protein. There was no effect of whey protein supplementation. These results show that resistance exercise provides an acute stimulation of the STARS pathway that is contraction mode dependent. The responses to acute exercise were more pronounced than responses to accumulated training, suggesting that STARS signalling is primarily involved in the initial phase of exercise-induced muscle adaptations.

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Listening… can involve the listener in an intense, efficacious, and complex set of communicative acts in which one is not speaking, discussing, or disclosing, but sitting quietly, watching, and feeling-the-place, through all the senses…. In the process, one becomes a part of the scene, hearing and feeling with it (Carbaugh 1999: 259).To listen this way involves much more than providing a chance for words to be spoken; it includes tuning in and getting the listening frequency clear. As a non-Indigenous person seeking to conduct qualitative research that listens to Aboriginal people, I need to ask how I can tune into the “active attentiveness” described by Carbaugh (1999) in order to listen in a manner that is appropriate, respectful and minimises my inherent white privilege. In addressing this question I draw on the work of Indigenous authors and academics, critical whiteness studies and my own experiences learning from Aboriginal people in a number of contexts over the past ten to fifteen years.History in Australia since colonization has created a situation where Aboriginal voices are white noise to the ears of many non-Indigenous people. This paper proposes that white privilege and the resulting white noise can be minimised and greater clarity given to Aboriginal voices by privileging Indigenous knowledge and ways of working when addressing Indigenous issues. To minimise the interference of white noise, non-Indigenous people would do well to adopt a position that recognises, acknowledges and utilises some of the strengths that can be learned from Aboriginal culture and Indigenous authors.This paper outlines a model of apprentice, allied listening for non-Indigenous researchers to adopt when preparing to conduct research alongside Indigenous people. Such an approach involves Re-learning of history, Reviewing of the researcher’s beliefs and placing Relating at the centre of the listening approach. Each of these aspects of listening is based on privileging of Indigenous voices.

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As a white researcher setting out on a research journeywith Indigenous people, how could I deal with theparadox of being part of the problem I was seeking toaddress? Awareness of, and desire to minimise, theimpact of my white privilege would not automaticallycancel it out. Activist researchers who have challengedpowerful systems have a history of being condemned andostracised by colonial centres of power. Would it be myfate to be condemned by the colonial centre of power inwhich I found myself; the academy? Would I also becondemned by those not in positions of power? Whatsignposts could show me how to act, what to do and howto undertake the research journey?This paper outlines the intersecting theories I meldedtogether to use as a map for a critical activist allystandpoint when conducting research in IndigenousPrisoner Education in Western Australia. Drawing ontheories of whiteness, power, critical pedagogy, activismand standpoint theory, I attempt to navigate a directionthat allows for the struggle, uncertainties and paradoxesthat are what it means to work critically as an alliedactivist. I explore some of the challenges I face as acritical, activist ally who is exploring Indigenouseducation in Western Australian prisons. I invite audiencediscussion, feedback and reflection on these challenges

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High incarceration rates of Aboriginal Western Australians leads to between 1800 and 2000 Aboriginal prisoners at any one time. Despite this little is written or noted in Australian peer reviewed academic literature about education provision to Aboriginal prisoners. "Closing the Gap: learning from and privileging Aboriginal voices to learn what helps and hinders educationin WA prisons" is a PhD project nearing submission. It has been conducted in partnership with the Deaths in Custody Watch Committee as we ll as with the support of a local community legalservice. The findings are relevant beyond a prison context.This paper specifically focuses on how understandings of the concept of productivity can differ. Itconsiders what might or might not be helpful in achieving productive educational and trainingoutcomes in Western Australian prisons for Indigenous individuals, families and communities. Itrelies heavily on the words of the author's teachers; the Aboriginal participants in the project alongside Indigenous authors and academics. The paper concludes by considering implications for developing and evaluating training programs in more flexible ways that respect diversity.

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Abnormalities within white matter (WM) have been identified in autism spectrum disorder (ASD). Although there is some support for greater neurobiological deficits among females with ASD, there is little research investigating sex differences in WM in ASD. We used diffusion tensor imaging (DTI) to investigate WM aberration in 25 adults with high-functioning ASD and 24 age-, sex- and IQ-matched controls. Tract-based spatial statistics (TBSS) was used to explore differences in WM in major tract bundles. The effects of biological sex were also investigated. TBSS revealed no differences in fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), or axial diffusivity (AD) between groups. There were no effects of biological sex. We consider whether methodological differences between past studies have contributed to the highly heterogeneous findings in the literature. Finally, we suggest that, among a high-functioning sample of adults with ASD, differences in WM microstructure may not be related to clinical impairment.

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The striated muscle activator of Rho signaling (STARS) protein and members of its downstream signaling pathway, including myocardin-related transcription factor-A (MRTF-A) and SRF, are increased in response to prolonged resistance exercise training but also following a single bout of endurance cycling. The aim of the present study was to measure and compare the regulation of STARS, MRTF-A and SRF mRNA and protein following 10 weeks of endurance training (ET) versus resistance training (RT), as well as before and following a single bout of endurance (EE) versus resistance exercise (RE). Following prolonged training, STARS, MRTF-A and SRF mRNA levels were all increased by similar magnitude, irrespective of training type. In the training-habituated state, STARS mRNA increased following a single-bout RE when measured 2.5 and 5 h post-exercise and had returned to resting level by 22 h following exercise. MRTF-A and SRF mRNA levels were decreased by 2.5, 5, and 22 h following a single bout of RE and EE exercise when compared to their respective basal levels, with no significant difference seen between the groups at any of the time points. No changes in protein levels were observed following the two modes of exercise training or a single bout of exercise. This study demonstrates that the stress signals elicited by ET and RT result in a comparable regulation of members of the STARS pathway. In contrast, a single bout of EE and RE, performed in the trained state, elicit different responses. These observations suggest that in the trained state, the acute regulation of the STARS pathway following EE or RE may be responsible for exercise-specific muscle adaptations.