63 resultados para Microscopic analyses

em Deakin Research Online - Australia


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Allergenic proteins present in pollen grains, when inhaled, interact with the airways to cause an attack of asthma in susceptible humans. In one system, grass pollen grains rupture osmotically in rainfall, releasing allergen-containing inhalable particles into the atmosphere. In contrast, birch tree pollen grains do not rupture under these conditions, yet the major allergen, Bet v 1, has been detected in the atmosphere in inhalable particles of unknown origin. It is possible that Bet v 1 may diffuse from intact settled pollen grains and the allergenic material may again become airborne, interacting with settled fine particles from other sources prior to resuspension. This study investigates the mechanism for the release of birch pollen allergen-containing inhalable particles from pollen grains. We propose the hypothesis that (1) airborne birch pollen grains settle on nearby leaf surfaces; (2) then, following light rainfall, the grains germinate and, (3) later, pollen tubes burst, releasing inhalable particles carrying Bet v 1 into the atmospheric aerosol.   We used microscopic analyses of pollen behaviour following anther opening, a Burkard volumetric trap for pollen counts and a high volume air sampler with a two-stage cascade impactor for quantitative immunochemical analyses of Bet v 1. On dry days of high birch pollen count (48 grains/m3, 1.5 ng/m3 of Bet v 1), we found that the surfaces of birch leaves became coated with pollen. This ”pollen rain” is a source of secondary emission of allergens into the atmosphere. We observed that following light rainfall (<1 mm per day), about 80% of the birch pollen grains germinated, producing pollen tubes, especially in the sticky surface secretions of leaf glands. These pollen tubes may grow up to 300 μm in length prior to rupturing, each releasing about 400 starch granules coated with allergen molecules that may, after drying, be dispersed into the aerosol. On these days following light rainfall, the highest atmospheric levels of Bet v 1 (1.18 ng/m3) are associated with inhalable particles. Following heavy rainfall, both pollen and inhalable particles are washed from the atmosphere. Immunoprinting studies show that Bet v 1 is associated with starch granules rather than the smaller orbicules. Bet v 1 is present in the atmosphere in large particles, i.e. in particular pollen grains and in inhalable particles, i.e. in particular starch granules.

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A combination of X-ray powder diffraction (XRD) and nuclear magnetic resonance (NMR) studies has demonstrated that attempted substitutions of Al, V and Nb into the framework of LiTi2(PO4)3 yield several impurity phases in addition to direct substitutions of Al into Ti and V, Nb into P sites. Direct substitutions were confirmed by changes in the unit cell dimensions as indicated by the peak shifts observed in the X-ray diffractographs and by analyses of the 27Al and 31P magic angle spinning (MAS) spectra. A major impurity phase was identified as AlPO4 (found in at least two polymorphs) and the amount present increases with increasing Al additions. The formation of AlPO4 appeared to be enhanced by further V but suppressed by Nb substitution. These results suggest that the presence of AlPO4 , together with the non-stoichiometric modified LTP, may be the cause for the observed densification of this material upon sintering and the increased ionic conductivity.

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We evaluated an Internet-based psychological intervention supported by either general practitioners or psychologists (Panic Online), and a Primary-care Evidence-based Psychological-interventions (PEP) strategy which involves training GPs to deliver specific psychological interventions.

Economic modelling suggests that Panic Online is cost-effective when supported by either GPs or psychologists.

Threshold analysis of the psychological training of GPs suggests that a modest effect size for clinical benefit would be sufficient to provide an acceptable cost-effectiveness ratio.

The sustainability of these approaches depends on a range of factors, including funding, workforce availability, and acceptability to consumers and health care providers.

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In this study, Australian brown coal fly ash particles have been collected from power station and analysed by scanning electron microscopy to obtain morphological information and elemental composition of individual particles. The most common particles found to be the irregular shape particle aggregates. Other shapes include ball shape with smooth surface and with some attachments; and crystal shape fine particles. The X-ray spectra of each fly ash particle revealed five groups of elemental composition, they are Si-rich particles; Ca-rich particles; Fe-rich particles; particles with Mg-Ca Matrix and particles with Si-Ca matrix. A particle sire distribution analysis has been conducted using particle size analyser and found to have a mean particle size of 21fim. The sample then was separated into fine and coarse fractions using aerodynamic classifier, and the elemental composition of both fractions were determined by ICP-AES. Borate fusion and acid dissolution method was used for sample preparation. It is found that some environmental sensitive elements such as Zn, Pb, Ni, K and Cu are enriched in fine fly ash particles. Ca has much higher contents in fine particles as well. Si and Mg have higher concentrations in coarse particles.

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The demolition of building structures produces enormous amounts of waste materials. In most current demolition projects, a great number of demolished materials are directly sent to landfill after their primary usage due to the difficulties in finding their next usage immediately. At the same time, because of limited supply of second-hand materials, new and high quality materials are used in construction projects whose design standards can be fitted using the secondary or used materials. However, this is an inefficient method to reduce waste because off the flow nature of the current waste-exchange systems and the demolition procedure. The recent concept using deconstruction rather than destruction for demolishing a constructed facility fails to achieve widespread understanding or acceptance due to various practical limitations. In this paper, for the purpose of envisaging the deconstruction implementations in practice and promoting cascading usages of construction materials, the concept of electronic demolition (e-Demotion, eDemolition) is put forward for the first time. E-demolition is a virtual demolition approach by which the demolition information, progress and outputs are operated before the physical demolition. Furthermore, the authors set up the essential models to implement electronic demolition of buildings from the viewpoints of demolition progress, business, and information. Each model is demonstrated in accord with the conventional demolition practice and subject to the ideal deconstruction implementation. Following the electronic demolition of a real project, the physical demolition can be anticipated with a minimum of construction waste emission.

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Both the construction and real estate sectors have been considered vital productive drivers for the economic development of a nation. Multinational economic analyses on these two sectors over a long period enable a better comprehension of their effects and interrelationships. Based on the recently published Organisation for Economic Co-operation and Development (OECD) input-output database at constant prices, this paper compares the real estate and construction sectors of six countries in terms of their shares in gross national product and gross national income. The push and pull effects of these two sectors onto the whole economy are further determined using forward and backward linkage indicators respectively. In addition, the interactions between themselves are formulated in terms of direct and total input parameters. This research provides a numerical approach to examine the economic influences and sectorial correlation of the real estate and construction sectors.

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With the increasing stock of aging structures, the strategy to model and analyse the retirement of deteriorated structures is becoming a challenging research field. As the converse of construction of new projects, the retirement of constructed facilities puts forward some new management and economics themes as well as environmental issues or adds some new contents even though the same issues are faced in construction. This research aims to model and analyse the maintenance and demolition activities of constructed facilities from economic and environmental perspectives. Both cost and carbon dioxide of maintenance and demolition activities are formulated based on those of construction activities and applied to an empirical study on deteriorated bridges. Further modelling and analysis is investigated to elaborate the demolition stage of a structure. The developed modelling and analysis methodology may enable the decision maker to determine the retirement strategy for a deteriorated structure.

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This case study examined the ability of three first year non-major chemistry students to understand chemical concepts according to Johnstone’s three levels of chemical representations of matter. Students’ background knowledge in chemistry proved to be a powerful factor in their understanding of the submicroscopic level. The results show that modelling ability is not necessarily innate, but it is a skill to be learnt. Each of the students’ modelling abilities with chemical representations improved with instruction and practice. Generally, as modelling skills improved so did students’ understanding of the relevant chemical concept. Modelling ability is described according to Grosslight et al.’s three–tiered level and the ability to traverse the three levels of chemical representation of matter.

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The development of critical skills in social work students and practitioners has been a major focus of social work education and training in recent years. Critical incident analysis has developed as a tool to aid critical reflection in practice, in health and social work. This paper provides an overview of the use of the tool in these fields. It then reports on a demonstration project which sought to examine how critical incident analysis might be used as a form of assessment and as a supervisory tool by social work students and practice teachers. An evaluation of the project is provided. Completion of critical incident analyses using the framework was found to provide a structured approach to critical reflection. It assisted the integration of theory and practice and the examination of value issues. Students and practice teachers identify its use in supervision and its potential as an assessment tool. The paper concludes with a discussion on the potential uses of critical incident analyses, with particular attention given to its use to develop anti-oppressive practice.

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The natriuretic peptide (NP) family consists of multiple subtypes in teleosts, including atrial, B-type, ventricular, and C-type NPs (ANP, BNP, VNP, CNP-1–4, respectively), but only ANP, BNP, CNP-3, and CNP-4 have been identified in tetrapods. As part of understanding the molecular evolution of NPs in the tetrapod lineage, we identified NP genes in the chicken genome. Previously, only BNP and CNP-3 have been identified in birds, but we characterized two new chicken NP genes by cDNA cloning, synteny and phylogenetic analyses. One gene is an orthologue of CNP-1, which has only ever been reported in teleostei and bichir. The second gene could not be assigned to a particular NP subtype because of high sequence divergence and was named renal NP (RNP) due to its predominant expression in the kidney. CNP-1 mRNA was only detected in brain, while CNP-3 mRNA was expressed in kidney, heart, and brain. In the developing embryo, BNP and RNP transcripts were most abundant 24 h post-fertilization, while CNP mRNA increased in a stage-dependant manner. Synthetic chicken RNP stimulated an increase in cGMP production above basal level in chicken kidney membrane preparations and caused a potent dose-dependant vasodilation of pre-constricted dorsal aortic rings. From conserved chromosomal synteny, we propose that the CNP-4 and ANP genes have been lost in chicken, and that RNP may have evolved from a VNP-like gene. Furthermore, we have demonstrated for the first time that CNP-1 is retained in the tetrapod lineage.

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Lifecycle approaches have found their wide applications in analyzing, evaluating and assessing technologies and management methods in the infrastructure systems. While environmental problems such as global warming have become a serious issue in the world, researchers and practicing engineers in civil engineering have to pay attention to environmental impacts as well as function, safety, cost and aesthetics in the
whole lifecycle of civil infrastructures. In addition to the normal lifecycle activities accompanied with operation and aging, the effects of natural hazards such as earthquakes with a low occurrence probability but a high
hazard loss require a full consideration in determining both lifecycle cost and lifecycle environmental impact. In this research, an approach is proposed to predetermine the lifecycle environmental impact and costs of bridges from their construction and maintenance as well as the losses and recovery after natural hazards. Based on this research, it becomes possible to quantitatively outline the roles of bridge construction, maintenance and earthquake in both environmental impact and cost in the whole lifetime of a bridge, especially their constituent parts from seismic losses and recoveries.

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In this paper, I describe methodological applications of Deleuze and Guattari's (1987) understanding of rhizomatic knowledge systems. I draw on rhizo-textual analyses of two different policy documents used in Australia to direct teachers in their teaching of English in primary (elementary) schools.

A rhizo-textual analysis is not concerned with following traditional, scientifically rigorous channels through a study; from data collection, through analysis, to findings that report some objectively discovered truth. Rather, a rhizo-textual analysis is a mapping of connections, of the fleshy tubers that are the rhizome. The mapping draws on various, and often contradictory work, ideas and concepts. What would seem to be "disparate phenomena" enables me to "connect diverse fragments of data in ways that produce new linkages and reveal discontinuities" (Alvermann, 2000, p. 118).

As Deleuze and Guattari point out, "A rhizome ceaselessly establishes connections between semiotic chains, organizations of power, and circumstances relative to the arts, social sciences, and social struggles" (1987, p. 7). This ceaselessness of the connections between rhizomes shifts attention away from the construction of a particular reading of any text towards a new careful attendance to the multiplicity of linkages that can be mapped between any text and other texts, other readings, other assemblages of meaning. Elizabeth Grosz describes rhizomatic texts as "a process of scattering thoughts, scrambling terms, concepts and practices, forging linkages, becoming a form of action" (1995, p. 126)

Within the policy texts I have analysed, this scrambling and scattered process establishes connections between disparate discursive systems, about literacy, about texts, about students and how students learn, and about teaching so that the version of literacy teaching that is produced seems to be normative, to be unquestionably rational, and therefore to be beyond critique.