24 resultados para Non-Piston-Like Displacement

em Deakin Research Online - Australia


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Sporting terms have been used as metaphor and analogy to describe and prescribe life experiences. It has been suggested that the use of sport terminology can assist in the general understanding of complex terms and situations, however, the use of sport as metaphor and analogy for many aspects of social understanding can have negative consequences. The analogy of sport and war seems to be particularly prevalent within football, irrespective of the code or culture in which it is played. This article demonstrates the popular understanding of Australian Rules ‘football as war’ through two complementary studies. The first study investigates the representation of Australian Rules football as war, specifically through the analysis of both images and text on the front covers of the sport ‘lift-out’ sections of two prominent Melbourne newspapers, The Herald Sun and The Age. The second study examines whether people interpret non-war-like images of Australian Rules football in war-like terms. Forty-five undergraduate sport marketing and management students were asked to write about one of four different images of football players and coaches interacting, which revealed that football is understood as war. Further, when prompted by an image of football players and coaches interacting, people in this study interpreted the interactions as consistently war-like. Coaches were portrayed as militaristic generals and the athletes as soldiers. Implications for management, education and practice are discussed.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In the trypsin superfamily of serine proteases, non-trypsin-like primary specificities have arisen in only two monophyletic descendent subbranches. We have recreated an ancestor to one of these subbranches (granzyme) using phylogenetic inference, gene synthesis, and protein expression. This ancestor has two unusual properties. First, it has broad primary specificity encompassing the entire repertoire of novel primary specificities found in its descendents. Second, unlike extant members that have narrow primary specificities, the ancestor exhibits tolerance to mutational changes in primary specificity-conferring residues—that is, structural plasticity. Molecular modeling and mutagenesis studies indicate that these unusual properties are due to a particularly wide substrate binding pocket. These two crucial properties of the ancestor not only distinguish it from its extant descendents but also from the trypsin-like proteases that preceded it. This indicates that a despecialization step, characterized by broad specificity and structural plasticity, underlies evolution of new primary specificities in this protease superfamily.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Membranes are crucial in modern industry and both new technologies and materials need to be designed to achieve higher selectivity and performance. Exotic materials such as nanoparticles offer promising perspectives, and combining both their very high specific surface area and the possibility to incorporate them into macrostructures have already shown to substantially increase the membrane performance. In this paper we report on the fabrication and engineering of metal-reinforced carbon nanotube (CNT) Bucky-Paper (BP) composites with tuneable porosity and surface pore size. A BP is an entangled mesh non-woven like structure of nanotubes. Pure CNT BPs present both very high porosity (>90%) and specific surface area (>400 m2/g). Furthermore, their pore size is generally between 20–50 nm making them promising candidates for various membrane and separation applications. Both electro-plating and electroless plating techniques were used to plate different series of BPs and offered various degrees of success. Here we will report mainly on electroless plated gold/CNT composites. The benefit of this method resides in the versatility of the plating and the opportunity to tune both average pore size and porosity of the structure with a high degree of reproducibility. The CNT BPs were first oxidized by short UV/O3 treatment, followed by successive immersion in different plating solutions. The morphology and properties of these samples has been investigated and their performance in air permeation and gas adsorption will be reported.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Objective: The relationship between personality and psychosis is well established. It has been suggested that this relationship may be partly accounted for by higher levels of depression in individuals with certain personality traits. We explored whether the link between personality and psychotic symptoms is already apparent in adolescence, and if this association would still hold when depression was controlled for. Method: 654 secondary school students were surveyed via self-report questionnaires measuring the Five-Factor model of personality (NEO-FFI), depression (CES-D) and psychotic-like experiences (CAPE). Results: Positive associations were found between Neuroticism and all CAPE-subscales except Magical Thinking, which was in turn associated with all other personality traits when at high levels. Agreeableness was negatively associated with all CAPE-subscales, while Openness to Experience was only positively associated with Persecutory Ideas and Magical Thinking. After controlling for depression, many of the significant associations remained. Conclusion: Our findings suggest that the chance of having psychotic like experiences is more likely for adolescents with certain personality traits. These associations are not fully explained by depression, especially when psychotic experiences are at higher levels. Future research is needed to investigate if these personality traits might put a person at risk for the development of full-blown psychosis.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

One of the principal strands of postcolonial theory and critical practice is the interrogation of received versions of colonial history. This paper investigates the extent to which three contemporary picture books, Gavin Bishop's The House that Jack Built, John Marsden and Shaun Tan's The Rabbits, and Thomas King and William Kent Monkman's A Coyote Columbus Story, mobilise postcolonial strategies in their representations of place. In particular, it focuses on how postcolonial textuality unsettles and transgresses notions of "homeliness" in narratives involving the displacement of colonised and colonising peoples. As the shifting power relations of colonialism render unhomely what has previously been homely (especially for colonised peoples), so they involve a contrary move in which unhomely spaces are changed into simulacra of lost or abandoned homes. Drawing upon Walter Benjamin's formulation of materialist historiography, Homi Bhabha describes what he terms 'the unhomely moment' as that in which personal and psychic histories intersect with the violent dislocations of colonialism. This paper will argue that such unhomely moments shape the visual and verbal narratives of The House that Jack Built, The Rabbits and A Coyote Columbus Story, all of which deal with the trauma which occurs when cultures previously geographically and psychically distant are brought into close contact with each other. Written to and for children who are citizens of postcolonial cultures, these texts disclose the unease which persists in contemporary societies where colonial histories are rehearsed and revisioned. However, the paper will argue that the three texts position readers in quite different ways; for instance, while the verbal text of The Rabbits constructs an implied author capable of speaking for the colonised and offering readers a very circumscribed subject position, Thomas King's narrative in A Coyote Columbus Story engages in a dialogic playfulness which allows readers to adopt a variety of reading positions. For each text, some key representations of unhomely moments will be considered, and the paper will explore the extent to which they construct forms of temporality which negotiate the space between history and its significances within crosscultural and intercultural formations.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The subjective effects and therapeutic potential of the shamanic practice of journeying is well known. However, previous research has neglected to provide a comprehensive assessment of the subjective effects of shamanic-like journeying techniques on non-shamans. Shamanic-like techniques are those that demonstrate some similarity to shamanic practices and yet deviate from what may genuinely be considered shamanism. Furthermore, the personality traits that influence individual susceptibility to shamanic-like techniques are unclear. The aim of the present study was, thus, to investigate experimentally the effect of shamanic-like techniques and a personality trait referred to as "ego boundaries" on subjective experience including mood disturbance. Forty-three non-shamans were administered a composite questionnaire consisting of demographic items and a measure of ego boundaries (i.e., the Short Boundary Questionnaire; BQ-Sh). Participants were randomly assigned to one of three conditions: listening to monotonous drumming for 15 minutes coupled with one of two sets of journeying instructions; or sitting quietly with eyes closed for 15 minutes. Participants' subjective experience and mood disturbance were retrospectively assessed using the Phenomenology of Consciousness Inventory (PCI) and the Profile of Mood States-Short Form, respectively. The results indicated that there was a statistically significant difference between conditions with regard to the PCI major dimensions of visual imagery, attention and rationality, and minor dimensions of imagery amount and absorption. However, the shamanic-like conditions were not associated with a major reorganization of the pattern of subjective experience compared to the sitting quietly condition, suggesting that what is typically referred to as an altered state of consciousness effect was not evident. One shamanic-like condition and the BQ-Sh subscales need for order, childlikeness, and sensitivity were statistically significant predictors of total mood disturbance. Implications of the findings for the anthropology of consciousness are also considered.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Shamanism has remained an integral part of indigenous healing rituals since ancient times and is currently attracting interest as a complementary therapeutic technique in psychology. Recently, shamanic-like techniques have been used to facilitate changes in the phenomenology of nonshamans. However, such research has largely been delimited to a single shamanic-like technique (i.e., drumming), and the role of personality traits with regards to receptivity to this technique has been neglected. The purpose of the present study was to investigate experimentally the effect of different shamanic-like techniques and the cognitive-perceptual factor of the schizotypy construct on phenomenology. One hundred and four non-shamans were randomly assigned to one of three conditions: Drumming, Ganzfeld, or Sitting Quietly with Eyes Open. Participants' phenomenology was assessed using the Phenomenology of Consciousness Inventory, Phenomenology associated with shamanic-like techniques appeared to be statistically significantly different from phenomenology associated with sitting quietly with eyes open. Furthermore, high cognitive-perceptual participants reported significant alterations in phenomenology compared to their low cognitive-perceptual counterparts. Methodological shortcomings of the present study are discussed and suggestions for future research are advanced.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Studies have found that shamanic practices are associated with statistically significant reductions in mood disturbance relative to baseline. However, contrary results were obtained for non-shamanic practitioners exposed to shamanic-like techniques. These inconsistent results may be partially due to a personality trait referred to as schizotypy, which has been demonstrated to influence susceptibility to shamanic-like techniques. Furthermore, given that an integral feature of shamanism is the production of altered states of awareness and altered experiences, and that shamanism is associated with health benefits, perhaps the production of such alterations affects health benefits. Consequently, the present study aimed to investigate whether altered state of awareness and altered experience mediated the association between schizotypy and mood disturbance during exposure to a shamanic-like condition. Sixty-nine non-shamans were randomly assigned to one of two conditions: shamanic-like journeying with drumming or sitting quietly with eyes open. Total mood disturbance-change was significantly negatively correlated with schizotypy and altered experience -- but not altered state of awareness -- and these correlations were significantly stronger for the shamanic-like journeying condition relative to the control condition. Furthermore, altered experience significantly mediated the association between schizotypy and total mood disturbance-change during exposure to shamanic-like journeying.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Aim
The purpose of this paper is to give an overview of the imaging techniques that are currently used to study the effects of exercise on bone architecture.

Current knowledge
It is now widely accepted that the prevention of osteoporosis must be initiated in childhood, because the immature skeleton is more responsive to physical loading. Exercise recommendations for bone health promotion must consider the effects of loading not only on the more traditional measures of bone mineral content and macroarchitecture, but also on the microarchitecture and structural properties of the skeleton. The latter requires high precision 3D methods like quantitative computed tomography and magnetic resonance imaging.

Prospects
Imaging resolutions used most commonly in exercise studies of children have sufficient precision to assess bone density and gross geometry. However, they remain insufficient to clearly depict and quantify the trabecular bone microarchitecture in vivo in humans.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The development and use of cocycles for analysis of non-autonomous behaviour is a technique that has been known for several years. Initially developed as an extension to semi-group theory for studying rion-autonornous behaviour, it was extensively used in analysing random dynamical systems [2, 9, 10, 12]. Many of the results regarding asymptotic behaviour developed for random dynamical systems, including the concept of cocycle attractors were successfully transferred and reinterpreted for deterministic non-autonomous systems primarily by P. Kloeden and B. Schmalfuss [20, 21, 28, 29]. The theory concerning cocycle attractors was later developed in various contexts specific to particular classes of dynamical systems [6, 7, 13], although a comprehensive understanding of cocycle attractors (redefined as pullback attractors within this thesis) and their role in the stability of non-autonomous dynamical systems was still at this stage incomplete. It was this purpose that motivated Chapters 1-3 to define and formalise the concept of stability within non-autonomous dynamical systems. The approach taken incorporates the elements of classical asymptotic theory, and refines the notion of pullback attraction with further development towards a study of pull-back stability arid pullback asymptotic stability. In a comprehensive manner, it clearly establishes both pullback and forward (classical) stability theory as fundamentally unique and essential components of non-autonomous stability. Many of the introductory theorems and examples highlight the key properties arid differences between pullback and forward stability. The theory also cohesively retains all the properties of classical asymptotic stability theory in an autonomous environment. These chapters are intended as a fundamental framework from which further research in the various fields of non-autonomous dynamical systems may be extended. A preliminary version of a Lyapunov-like theory that characterises pullback attraction is created as a tool for examining non-autonomous behaviour in Chapter 5. The nature of its usefulness however is at this stage restricted to the converse theorem of asymptotic stability. Chapter 7 introduces the theory of Loci Dynamics. A transformation is made to an alternative dynamical system where forward asymptotic (classical asymptotic) behaviour characterises pullback attraction to a particular point in the original dynamical system. This has the advantage in that certain conventional techniques for a forward analysis may be applied. The remainder of the thesis, Chapters 4, 6 and Section 7.3, investigates the effects of perturbations and discretisations on non-autonomous dynamical systems known to possess structures that exhibit some form of stability or attraction. Chapter 4 investigates autonomous systems with semi-group attractors, that have been non-autonomously perturbed, whilst Chapter 6 observes the effects of discretisation on non-autonomous dynamical systems that exhibit properties of forward asymptotic stability. Chapter 7 explores the same problem of discretisation, but for pullback asymptotically stable systems. The theory of Loci Dynamics is used to analyse the nature of the discretisation, but establishment of results directly analogous to those discovered in Chapter 6 is shown to be unachievable. Instead a case by case analysis is provided for specific classes of dynamical systems, for which the results generate a numerical approximation of the pullback attraction in the original continuous dynamical system. The nature of the results regarding discretisation provide a non-autonomous extension to the work initiated by A. Stuart and J. Humphries [34, 35] for the numerical approximation of semi-group attractors within autonomous systems. . Of particular importance is the effect on the system's asymptotic behaviour over non-finite intervals of discretisation.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The natriuretic peptides, atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP) are members of a family of hormones that play an important role in mammalian fluid and electrolyte balance. In the periphery, natriuretic peptides reduce blood volume and subsequently blood pressure by increasing renal natriuresis and diuresis and relaxation of vascular smooth muscle. The actions of natriuretic peptides are mediated via two membrane-linked guanylate cyclase receptors (NPR-GC); natriuretic peptide receptor-A (NPR-A) which has a high affinity for ANP and BNP; and natriuretic peptide receptor-B (NPR-B)which has the greatest affinity for CNP. A third receptor not linked to guanylate cyclase, natriuretic peptide receptor-C (NPR-C) also exists, which binds to ANP, BNP and CNP with a relatively equal affinity, and is involved with clearance of the peptides from the circulation and tissues. The natriuretic peptides are present in the brain and are particularly predominant in cardiovascular and fluid and electrolyte regulating areas such as the anteroventral third ventricle (AV3V) region. This distribution has led to the suggestion natriuretic peptides play a neuromodulatory role in the central control of fluid homeostasis. Natriuretic peptides in the brain have been observed to inhibit the release of other fluid and electrolyte regulating hormones such as arginine vasopressin (AVP) and angiotensin II (AII). Natriuretic peptides have also been identified in the non-mammalian vertebrates although information regarding the distribution of the peptides and their receptors in the non-mammalian brain is limited. In amphibians, immunohistochemical studies have shown that natriuretic peptides are highly concentrated in the preoptic region of the brain, an area believed to be analogous to the A\T3\ region in mammals, which suggests that natriuretic peptides may also be involved in central fluid and electrolyte regulation in amphibians. To date, CNP is the only natriuretic peptide that has been isolated and cloned from the lower vertebrate brain, although studies on the distribution of CNP binding sites in the brain have only been performed in one fish species. Studies on the distribution of ANP binding sites in the lower vertebrate brain are similarly limited and have only been performed in one fish and two amphibian species. Moreover, the nature and distribution of the natriuretic peptide receptors has not been characterised. The current study therefore, used several approaches to investigate the distribution of natriuretic peptides and their receptors in the brain of the amphibian Bufo marinus. The topographical relationship of natriuretic peptides and the fluid and electrolyte regulating hormone arginine vasotocin was also investigated, in order to gain a greater understanding of the role of the natriuretic peptide system in the lower vertebrate brain. Immunohistochemical studies showed natriuretic peptides were distributed throughout the brain and were highly concentrated in the preoptic region and interpeduncular nucleus. No natriuretic peptide-like immunoreactivity (NP-IR) was observed in the pituitary gland. Arginine vasotocin-like immunoreactivity (AvT-IR) was confined to distinct regions, particularly in the preoptic/hypothalamic region and pituitary gland. Double labelling studies of NP-JR and AvT-IR showed the peptides are not colocalised in the same neural pathways. The distribution of natriuretic peptide binding sites using the ligands 125I-rat ANP (125I-rANP) and 125I-porcine CNP (125I-pCNP) showed different distributions in the brain of B. marinus. The specificity of binding was determined by displacement with unlabelled rat ANP, porcine CNP and C-ANF, an NPR-C specific ligand. 125I-rANP binding sites were broadly distributed throughout the brain with the highest concentration in pituitary gland, habenular, medial pallium and olfactory region. Minimal 125I-rANP binding was observed in the preoptic region. Residual 125I-rANP binding in the presence of C-ANF was observed in the olfactory region, habenular and pituitary gland indicating the presence of both NPR-GC and NPR-C in these regions. 125I-pCNP binding was limited to the olfactory region, pallium and posterior pituitary gland. All 125I-pCNP binding was displaced by C-ANF which suggests that CNP in the brain of B. marinus binds only to NPR-C. Affinity cross-linking and SDS-PAGB demonstrated two binding sites at 136 kDa and 65 kDa under reducing conditions. Guanylate cyclase assays showed 0.1 µM ANP increased cGMP levels 50% above basal whilst a 10-fold higher concentration of CNP was required to produce the same result. Molecular cloning studies revealed a 669 base pair fragment showing 91% homology with human and rat NPR-A and 89% homology with human, rat and eel NPR-B. A 432 base pair fragment showing 67% homology to the mammalian NPR-C and 58% homology with eel NPR-D was also obtained. The results show natriuretic peptides and their receptors are distributed throughout the brain of B. marinus which indicates that natriuretic peptides may participate in a range of regulatory functions throughout the brain. The potential for natriuretic peptides to regulate the release of the fluid and electrolyte regulating hormone AVT also exists due to the high number of natriuretic peptide binding sites in the posterior pituitary gland. At least two populations of natriuretic peptide receptors are present in the brain of B. marinus, one linked to guanylate cyclase and one resembling the mammalian clearance receptor. Furthermore, autoradiography and guanylate cyclase studies suggest ANP may be the major ligand in the brain of B. marinus, even though CNP is the only natriuretic peptide that has been isolated from the lower vertebrate brain to date.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The Alzheimer’s disease Aβ peptide can increase the levels of cell-associated amyloid precursor protein (APP) in vitro. To determine the specificity of this response for Aβ and whether it is related to cytotoxicity, we tested a diverse range of fibrillar peptides including amyloid-β (Aβ), the fibrillar prion peptides PrP106–126 and PrP178–193 and human islet-cell amylin. All these peptides increased the levels of APP and amyloid precursor-like protein 2 (APLP2) in primary cultures of astrocytes and neurons. Specificity was shown by a lack of change to amyloid precursor-like protein 1, τ-1 and cellular prion protein (PrPc) levels. APP and APLP2 levels were elevated only in cultures exposed to fibrillar peptides as assessed by electron microscopy and not in cultures treated with non-fibrillogenic peptide variants or aggregated lipoprotein. We found that PrP106–126 and the non-toxic but fibril-forming PrP178–193 increased APP levels in cultures derived from both wild-type and PrPc-deficient mice indicating that fibrillar peptides up-regulate APP through a non-cytotoxic mechanism and irrespective of parental protein expression. Fibrillar PrP106–126 and Aβ peptides bound recombinant APP and APLP2 suggesting the accumulation of these proteins was mediated by direct binding to the fibrillated peptide. This was supported by decreased APP accumulation following extensive washing of the cultures to remove fibrillar aggregates. Pre-incubation of fibrillar peptide with recombinant APP18–146, the putative fibril binding site, also abrogated the accumulation of APP. These findings show that diverse fibrillogenic peptides can induce accumulation of APP and APLP2 and this mechanism could contribute to pathogenesis in neurodegenerative disorders.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This article focuses on the qualitative methodologies employed in a research project developed in collaboration with Aboriginal advisors and gaining an in-depth understanding of Aboriginal Victorian peoples' connection to their ancestral lands. It outlines why qualitative methodologies were used and highlights the ethical dimensions of working with Aboriginal Victorian communities. A research partnership was developed between Aboriginal Victorian communities and the non-Aboriginal researcher and this process was emphasised because in the past Australian Indigenous people have been grossly exploited in health research. The methods of semi-structured interviews and focus groups were used to gain a better understanding of this topic. The novel point of this article is that it provides an honest reflection of the benefits and limitations of this qualitative research process from the perspectives of a non-Aboriginal researcher and an Aboriginal participant, when emphasis is placed on a collaborative approach. The paper outlines what a successful qualitative research project looks like in Victorian Aboriginal communities. This can be used as a blueprint not only for working with Victorian Aboriginal communities, who have been marginalised within Australian society, but may also be relevant to other culturally diverse communities throughout the world.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Multilobal fibres contain several grooves and have higher surface area than round fibres. Cell density can be enhanced when cultured on scaffolds manufactured with multilobal fibres. This study compared the cell growth of dermal fibroblasts and osteoblast-like SaOS2 cells on polymeric scaffolds produced from multilobal fibres to the conventional round-fibred scaffolds. Cells were cultured on round nylon 6,6, trilobal nylon 6,6, round polyethylene terephthalate (PET) and multilobal PET scaffolds for 14 days. There were more cells cultured on trilobal nylon 6,6 and PET multilobal scaffolds than their round counterparts. Preference to the type of multilobal scaffolds was cell dependent. Fibroblasts increased by 21.8 ± 1.9 fold to 6.3 × 105 cells (p < 0.001) when cultured on trilobal nylon 6,6 scaffolds while SaOS2 cells exhibited a 16.7 ± 2.8 fold increase (2.9 × 105 cells, p < 0.001) on the multilobal PET scaffolds after 14 days of culture. The ability of multilobal fibres to accommodate large quantities of cells presents an excellent alternative to round fibres as scaffolds for tissue engineering.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In recent times, biotechnological applications of microbial lipases in synthesis of many organic molecules have rapidly increased in non-aqueous media. Microbial lipases are the working horses' in biocatalysis and have been extensively studied when their exceptionally high stability in non-aqueous media has been discovered. Stability of lipases in organic solvents makes them commercially feasibile in the enzymatic esterification reactions. Their stability is affected by temperature, reaction medium, water concentration and by the biocatalyst's preparation. An optimization process for ester synthesis from pilot scale to industrial scale in the reaction medium is discussed. The water released during the esterification process can be controlled over a wide range and has a profound effect on the activity of the lipases. Approaches to lipase catalysis like protein engineering, directed evolution and metagenome approach were studied. This review reports the recent development in the field of non-aqueous microbial lipase catalysis and factors controlling the esterification/transesterification processes in organic media.