470 resultados para Species interaction


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Purpose This chapter examines an episode of pretend play amongst a group of young girls in an elementary school in Australia, highlighting how they interact within the membership categorization device family to manage their social and power relationships. Approach Using conversation analysis and membership categorization analysis, an episode of video-recorded interaction that occurs amongst a group of four young girls is analyzed. Findings As disputes arise amongst the girls, the mother category is produced as authoritative through authoritative actions by the girl in the category of mother, and displays of subordination on the part of the other children, in the categories of sister, dog and cat. Value of paper Examining play as a social practice provides insight into the social worlds of children. The analysis shows how the children draw upon and co-construct family-style relationships in a pretend play context, in ways that enable them to build and organize peer interaction. Authority is highlighted as a joint accomplishment that is part of the social and moral order continuously being negotiated by the children. The authority of the mother category is produced and oriented to as a means of managing the disputes within the pretend frame of play.

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Particulate matter is common in our environment and has been linked to human health problems particularly in the ultrafine size range. A range of chemical species have been associated with particulate matter and of special concern are the hazardous chemicals that can accentuate health problems. If the sources of such particles can be identified then strategies can be developed for the reduction of air pollution and consequently, the improvement of the quality of life. In this investigation, particle number size distribution data and the concentrations of chemical species were obtained at two sites in Brisbane, Australia. Source apportionment was used to determine the sources (or factors) responsible for the particle size distribution data. The apportionment was performed by Positive Matrix Factorisation (PMF) and Principal Component Analysis/Absolute Principal Component Scores (PCA/APCS), and the results were compared with information from the gaseous chemical composition analysis. Although PCA/APCS resolved more sources, the results of the PMF analysis appear to be more reliable. Six common sources identified by both methods include: traffic 1, traffic 2, local traffic, biomass burning, and two unassigned factors. Thus motor vehicle related activities had the most impact on the data with the average contribution from nearly all sources to the measured concentrations higher during peak traffic hours and weekdays. Further analyses incorporated the meteorological measurements into the PMF results to determine the direction of the sources relative to the measurement sites, and this indicated that traffic on the nearby road and intersection was responsible for most of the factors. The described methodology which utilised a combination of three types of data related to particulate matter to determine the sources could assist future development of particle emission control and reduction strategies.

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Under seismic loads neither the response of the pile nor the response of ground are independent of each other, contrary what is normally assumed. In seismic design of buildings, dynamic response of a structure is determined by assuming a fixed base on sub-grade and neglecting the physical interaction between foundation and soil profile in which it is embedded. However, the seismic response of pile foundations in vibration sensitive soil profiles is significantly affected by the behaviour of supporting soil. This research uses validated Finite Element techniques to simulate the seismic behaviour of pile foundations embedded in multilayered vibration sensitive soils.

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A wide variety of experiments that involve the physics of small particles (m to cm in size) of planetary significance can be conducted on the Space Station. Processes of interest include nucleation and condensation of particles from a gas, aggregation of small particles into larger ones, and low velocity collisions of particles. Only experiments relevant to planetary processes will be discussed in detail here.

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This study investigates the development of teacher identity in a transnational context through an analysis of the voices of sixteen preservice teachers from Hong Kong who engage in interaction with primary students in an Australian classroom. The context for this research is the school-based experience undertaken by these preservice English as a second language teachers as part of their short language immersion (SLIM) program in Brisbane, Australia. Such SLIM programs are a genre of study abroad programs which have been gaining in popularity within teacher education in Australia, attended by preservice and inservice teachers from China, Hong Kong, Korea, and other Asian countries. This research is conducted at a time when the imperative to globalise higher education provision is a strategic factor in the educational policies of both Australia and Hong Kong. In Australia, international educational services now constitute the countrys third largest export with more than 400,000 students coming to Australia to study annually. In order to maintain Australias current global position as the third most popular Englishspeaking study destination, the government is now focusing on sustainability and the quality of the study experience being offered to international students (Bradley Review, 2008). In Hong Kong, the government sponsors both preservice and inservice English as a second language (ESL) teachers to undertake SLIM programs in Australia and other English-speaking countries, as part of their policy of promoting high levels of English proficiency in Hong Kong classrooms. Transnational teacher education is an important issue to which this study contributes insights into the affordances and constraints of a school-based experience in the transnational context. Second language teacher education has been defined as interventions designed to develop participants professional knowledge. In this study, it is argued that participation in a different community of practice helps to foreground tacit theories of second language pedagogy, making them visible and open to review. Questions of pedagogy are also seen as questions of teacher identity, constituting the way that one is in the classroom. I take up a sociocultural and poststructural framework, drawing on the work of James Gee and Mikhail Bakhtin, to theorise the construction of teacher identity as emerging through dialogic relations and socially situated discursive practices. From this perspective, this study investigates whether these teachers engage with different ways of representing themselves through appropriating, adapting or rejecting Discourses prevailing in the Australian classroom. Research suggests that reflecting on dilemmas encountered as lived experiences can extend professional understandings. In this study, the participants engage in a process of dialogic reflection on their intercultural classroom interactions, examining with their peers and their lecturer/researcher selected moments of dissonance that they have faced in the unfamiliar context of an Australian primary classroom. It is argued that the recursive and multivoiced nature of this process of reflection on practice allows participants opportunities to negotiate new understandings of second language teacher identity. Dialogic learning, based on the theories of Bakhtin and Vygotsky, provides the theoretic framing not only for the process of reflection instantiated in this study, but also features in the analysis of the participants second language classroom practices. The research design uses a combined discourse analytic and ethnographic approach as a logic-of-inquiry to explore the dialogic relationships which these second language teachers negotiate with their students and their peers in the transnational context. In this way, through discourse analysis of their classroom talk and reflective dialogues, assisted by the analytic tools of speech genres and discourse formats, I explore the participants ways of doing and being second language teachers. Thus, this analysis traces the process of ideological becoming of these beginner teachers as shifts in their understandings of teacher and student identities. This study also demonstrates the potential for a nontraditional stimulated recall interview to provide dialogic scaffolding for beginner teachers to reflect productively on their practice.

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The interaction of bare graphene nanoribbons (GNRs) was investigated by ab initio density functional theory calculations with both the local density approximation (LDA) and the generalized gradient approximation (GGA). Remarkably, two bare 8-GNRs with zigzag-shaped edges are predicted to form an (8, 8) armchair single-wall carbon nanotube (SWCNT) without any obvious activation barrier. The formation of a (10, 0) zigzag SWCNT from two bare 10-GNRs with armchair-shaped edges has activation barriers of 0.23 and 0.61 eV for using the LDA and the revised PBE exchange correlation functional, respectively, Our results suggest a possible route to control the growth of specific types SWCNT via the interaction of GNRs.

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In i6 families, half of which had an alcoholic parent, both parents and an adolescent were videotaped interacting with each other. Mothers, fathers and the adolescent in each family viewed the videotaped interaction and completed ratings of themselves and the other two family members on levels of anxiety, involvement, dominance and friendliness. In families with an alcoholic parent, adolescents and their mothers rated family members as less anxious than did adolescents and mothers in families without a drinking problem. Also mothers in the alcoholic families rated family members as being more involved, and their ratings were higher than mothers in other families. Alcoholic families rated parent-adolescent interactions as more dominant and friendlier. At least in these videotaped interactions where alcohol was not being consumed, mothers in alcoholic families adopted a more positive view of family members than mothers in other families. In addition, possibly due to the efforts of fathers not to drink and memories of interactions when he was drunk, alcoholic families perceived their family interactions as more dominant and friendlier than families without an alcohol-related problem. [Schweitzer R, Wilks j, Callan vJ. Alcoholism and family interaction.

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In this thesis, I contribute to the study of how arrangements are made in social interaction. Using conversation analysis, I examine a corpus of 375 telephone calls between employees and clients of three Community Home Care (CHC) service agencies in metropolitan Adelaide, South Australia. My analysis of the CHC data corpus draws upon existing empirical findings within conversation analysis in order to generate novel findings about how people make arrangements with one another, and some of the attendant considerations that parties to such an activity can engage in: Prospective informings as remote proposals for a future arrangement Focusing on how employees make arrangements with clients, I show how the employees in the CHC data corpus use prospective informings to detail a future course of action that will involve the recipient of that informing. These informings routinely occasion a double-paired sequence, where informers pursue a response to their informing. This pursuit often occurs even after recipients have provided an initial response. This practice for making arrangements has been previously described by Houtkoop (1987) as remote proposing. I develop Houtkoops analysis to show how an informing of a future arrangement can be recompleted, with response solicitation, as a proposal that is contingent upon a recipients acceptance. Participants understanding of references to non-present third parties In the process of making arrangements, references are routinely made to non-present third parties. In the CHC data corpus, these third parties are usually care workers. Prior research (e.g., Sacks & Schegloff, 1979; Schegloff, 1996b) explains how the use of recognitional references (such as the bare name Kerry), conveys to recipients that they should be able to locate the referent from amongst their acquaintances. Conversely, the use of non-recognitional references (such as the description a lady called Kerry), conveys that recipients are unacquainted with the referent. I examine instances where the selection of a recognitional or non-recognitional reference form is followed by a recipient initiating repair on that reference. My analysis provides further evidence thatthe existing analytic account of these references corresponds to the way in which participants themselves make sense of them. My analysis also advances an understanding of how repair can be used, by recipients, to indicate the inappositeness of a prior turn. Post-possible-completion accounts In a case study of a problematic interaction, I examine a misunderstanding that is not resolved within the repair space, the usual defence of intersubjectivity in interaction (cf. Schegloff, 1992b). Rather, I explore how the source of trouble is addressed, outside of the sequence of its production, with a post-possible-completion account. This account specifies the basis of a misunderstanding and yet, unlike repair, does so without occasioning a revised response to a trouble-source turn. By considering various aspects of making arrangements in social interaction, I highlight some of the rich order that underpins the maintenance of human relationships across time. In the concluding section of this thesis I review this order, while also discussing practical implications of this analysis for CHC practice.

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Sclerotinia sclerotiorum is a necrotrophic ascomycete fungus with an extremely broad host range. This pathogen produces the non-specific phytotoxin and key pathogenicity factor, oxalic acid (OA). Our recent work indicated that this fungus and more specifically OA, can induce apoptotic-like programmed cell death (PCD) in plant hosts, this induction of PCD and disease requires generation of reactive oxygen species (ROS) in the host, a process triggered by fungal secreted OA. Conversely, during the initial stages of infection, OA also dampens the plant oxidative burst, an early host response generally associated with plant defense. This scenario presents a challenge regarding the mechanistic details of OA function; as OA both suppresses and induces host ROS during the compatible interaction. In the present study we generated transgenic plants expressing a redox-regulated GFP reporter. Results show that initially, Sclerotinia (via OA) generates a reducing environment in host cells that suppress host defense responses including the oxidative burst and callose deposition, akin to compatible biotrophic pathogens. Once infection is established however, this necrotroph induces the generation of plant ROS leading to PCD of host tissue, the result of which is of direct benefit to the pathogen. In contrast, a non-pathogenic OA-deficient mutant failed to alter host redox status. The mutant produced hypersensitive response-like features following host inoculation, including ROS induction, callose formation, restricted growth and cell death. These results indicate active recognition of the mutant and further point to suppression of defenses by the wild type necrotrophic fungus. Chemical reduction of host cells with dithiothreitol (DTT) or potassium oxalate (KOA) restored the ability of this mutant to cause disease. Thus, Sclerotinia uses a novel strategy involving regulation of host redox status to establish infection. These results address a long-standing issue involving the ability of OA to both inhibit and promote ROS to achieve pathogenic success.

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This study investigates the time-course and post-receptoral pathway signaling of photoreceptor interactions when the rod (R) and three cone (L, M, S) photoreceptor classes contribute to mesopic vision. A four-primary photostimulator independently controls photoreceptor activity in human observers. The first experiment defines the temporal adaptation response of receptoral (L-, S-cone, rod) and post-receptoral (LMS, LMSR,+L-M) signaling and interactions. Here we show that nonopponent cone-cone interactions (L-cone, LMS, LMSR) have monophasic temporal response patterns whereas opponent signals (+L-M, S-cone) show biphasic response patterns with slower recovery. By comparison, rod-cone interactions with nonopponent signals have faster adaptation responses and reduced sensitivity loss whereas opponent rod-cone interactions are small or absent. Additionally, the rod-rod interaction differs from these interaction types and acts to increase rod sensitivity due to temporal summation but with a slower time course. The second experiment shows that the temporal profile of the rod signal alters the relative rod contributions to the three primary post-receptoral pathways. We demonstrate that rod signals generate luminance (LM) signals mediated via the MC pathway with all rod temporal profiles and chromatic signals (L/LM, S/LM) in both the PC and KC pathways with durations .75 ms. Thus, we propose that the change in relative weighting of rod signals within the post-receptoral pathways contributes to the sensitivity and temporal response of rod and cone pathway signaling and interactions.

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Thompson, E.J. & Simon, B.K. (2012). A revision of Calyptochloa C.E.Hubb. (Poaceae), with two new species and a new subspecies. Austrobaileya 8(4): 634652. Two new species of Calyptochloa C.E.Hubb. (Calyptochloa cylindrosperma E.J.Thomps. & B.K.Simon and C. johnsoniana E.J.Thomps. & B.K.Simon) endemic to central Queensland, and a new subspecies of Calyptochloa gracillima C.E.Hubb. (C. gracillima subsp. ipsviciensis E.J.Thomps. & B.K.Simon) endemic to southeast Queensland are described and illustrated.

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Background: Intra-amniotic infection accounts for 30% of all preterm births (PTB), with the human Ureaplasma species being the most frequently identified microorganism from the placentas of women who deliver preterm. The highest prevalence of PTB occurs late preterm (32-36 weeks) but no studies have investigated the role of infectious aetiologies associated with late preterm birth. Method: Placentas from women with late PTB were dissected aseptically and samples of chorioamnion tissue and membrane swabs were collected. These were tested for Ureaplasma spp. and aerobic/anaerobic bacteria by culture and real-time PCR. Western blot was used to assess MBA variation in ureaplasma clinical isolates. The presence of microorganisms was correlated with histological chorioamnionitis. Results: Ureaplasma spp. were isolated from 33/466 (7%) of placentas by culture or PCR. The presence of ureaplasmas, but not other microorganisms, was associated with histological chorioamnionitis (21/33 ureaplasma-positive vs. 8/42 other bacteria; p= 0.001). Ureaplasma clinical isolates demonstrating no MBA variation were associated with histological chorioamnionitis. By contrast, ureaplasmas displaying MBA variation were isolated from placentas with no significant histological chorioamnionitis (p= 0.001). Conclusion: Ureaplasma spp. within placentas delivered late preterm (7%) is associated with histological chorioamnionitis (p = 0.001). Decreased inflammation within chorioamnion was observed when the clinical ureaplasma isolates demonstrated variation of their surface-exposed lipoproteins (MBA). This variation may be a mechanism by which ureaplasmas modulate and evade the host immune response. So whilst ureaplasmas are present intra-amniotically they are not suspected because of the normal macroscopic appearance of the placentas and the amniotic fluid.

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Boron, which is an essential element for plants, is toxic to humans and animals at high concentrations. Layered double hydroxides (LDHs) and thermally activated LDHs have shown good uptake of a range of boron species in laboratory scale experiments when compared to current available methods, which are for the most part ineffective or prohibitively expensive. LDHs were able to remove anions from water by anion exchange, the reformation (or memory) effect and direct precipitation. The main mechanism of boron uptake appeared to be anion exchange, which was confirmed by powder X-ray diffraction (XRD) measurements. Solution pH appeared to have little effect on boron sorption while thermal activation did not always significantly improve boron uptake. In addition, perpetration of numerous LDHs with varying boron anions in the interlayer region by direct co-precipitation and anion exchange have been reported by a number of groups. The composition and orientation of the interlayer boron ions could be identified with reasonable certainty by applying a number of characterisation techniques including: powder XRD, nuclear magnetic resonance spectroscopy (NMR), X-ray photoelectron spectroscopy (XPS) and infrared (IR) spectroscopy. There is still considerable scope for future research on the application of LDHs for the removal of boron contaminants.

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Young adults represent the largest group of first time donors to the Australian Red Cross Blood Service, but they are also the least loyal group and often do not return after their first donation. At the same time, many young people use the internet and various forms of social media on a daily basis. Web and mobile based technological practices and communication patterns change the way that young people interact with one another, with their families, and communities. Combining these two points of departure, this study seeks to identify best practices of employing mobile apps and social media in order to enhance the loyalty rates of young blood donors. The findings reported in this paper are based on a qualitative approach presenting a nuanced understanding of the different factors that motivate young people to donate blood in the first place, as well as the obstacles or issues that prevent them from returning. The paper discusses work in progress with a view to inform the development of interactive prototypes trialling three categories of features: personal services (such as scheduling); social media (such as sharing the donation experience with friends to raise awareness); and data visualisations (such as local blood inventory levels). We discuss our translation of research findings into design implications.