990 resultados para Early farming, hunter-gatherer, palaeoecology, phytoliths, pland macrofossils, Soust Asiathea
Resumo:
This paper aims to explore the experiences of newly qualified teachers and their supervising principals who work in schools situated in various high-poverty areas of Queensland, Australia. It is informed by data collected in the context of an Australian teacher education program, Exceptional Teachers for Disadvantaged Schools (ETDS). Now in its third year, this program was designed to prepare highly skilled pre-service teachers to work in schools that have large numbers of students from disadvantaged or low socio-economic status (SES) backgrounds. Addressing the oft-stated need to prepare high-quality teachers for low SES schools, high-achieving undergraduate education students were invited to participate in two years of specialised curriculum to prepare them for the schools that need them the most, which are also the schools that are often difficult to staff. Pre-service teachers in this program do all their teaching practicum placements in challenging or complex schools. In 2011, some of this cohort did their practicum teaching in schools with large numbers of Indigenous students and several went on to teach in remote communities after graduation. These graduates and the leaders of the schools they work in are the primary informants for this paper.
Resumo:
Capture fisheries and aquaculture have been a major source of food and providers of economic benefits to many communities around the world for a very long time. While the history of aquaculture or fish farming can be traced back for more than 2000 years in some corners of the globe, notably in China, Japan and the Mediterranean, this is not true everywhere, where in general, fish farming is a relatively new industry. Rapid human population growth and increasing urbanisation over the last 20 to 40 years has meant that while fish consumption has doubled globally, returns from capture fisheries have remained static or have declined due to overexploitation and rising pollution levels, with some fisheries either closing or becoming economically unviable. Data from studies suggest that this trend is unlikely to be reversed unless appropriate fisheries management allows depleted wild stocks to rebuild. This has occurred during a time when demand for fish products has grown, in part due to improved purchasing power in some developing countries and changing dietary habits where fish are now considered to have a positive impact on health. Based on the projected population growth over the next two decades, Food and Agricultural Organization (FAO) estimates that at least an additional 40 million tonnes of aquatic food will be required to maintain the current per capita consumption (FAO 2006).
Resumo:
This paper examines teacher accountability and authority in early childhood policy. It reports on data from a study that investigated the influences affecting early childhood teacher decision-making at the preschool level in Victoria, Australia. Using a question raised by Ball ‘Where are the teachers in all this [policy]?’ provided a starting point for the critical discourse analysis into how forms of control, teacher authority, obligation and constraint within policies potentially influenced teachers’ curriculum decisions. The study found that despite no government-mandated curriculum framework at the time, teachers were held accountable for their curricular practice. Yet as professionals, early childhood teachers were denied public acknowledgement of their expertise as they were almost invisible in policy. In the four policies analysed, proprietors of early childhood settings and preschool agencies held authority over curriculum. Subsequently, teachers’ authority as professionals with curricular knowledge was diminished.
Resumo:
A numerical investigation of the behaviour of fuel injection through a porous surface in an inlet-fuelled, radial-farming scramjet is presented. The performance of porous fuel injection is compared to discrete port hole injection at an equivalence ratio of φ ≈ 0.4 for both cases. The comparison is performed at a Mach 6.5 flow condition with a total specific enthalpy of 4.3 MJ/kg. The numerical results are compared to experiments performed in the T4 shock tunnel where available. The presented results demonstrate for the first time, that porous fuel injection has the potential to outperform port hole injectors in scramjet engines in terms of fuel-air mixing, ignition delays and achievable combustion efficiencies despite reduced fuel penetration heights.
Resumo:
This paper reports on the experimental testing of oxygen compatible ceramic matrix composite porous injectors in a nominally two-dimensional hydrogen fuelled and oxygen enriched radical farming scramjet in the T4 shock tunnel facility. All experiments were performed at a dynamic pressure of 146 kPa, an equivalent flight Mach number of 9.7, a stagnation pressure and enthalpy of 40MPa and 4.3 MJ/kg respectively and at a fuelling condition that resulted in an average equivalence ratio of 0.472. Oxygen was pre-mixed with the fuel prior to injection to achieve enrichment percentages of approximately 13%, 15% and 17%. These levels ensured that the hydrogen-oxidiser mix injected into the engine always remained too fuel rich to sustain a flame without any additional mixing with the captured air. Addition of pre-mixed oxygen with the fuel was found to significantly alter the performance of the engine; enhancing both combustion and ignition and converting a previously observed limited combustion condition into one with sustained and noticeable combustion induced pressure rise. Increases in the enrichment percentage lead to further increases in combustion levels and acted to reduce ignition lengths within the engine. Suppressed combustion runs, where a nitrogen test gas was used, confirmed that the pressure rise observed in these experiments as attributed to the oxygen enrichment and not associated with the increased mass injected.
Resumo:
This paper reports on an investigation of the flow/chemistry coupling inside a nominally two-dimensional inlet-fuelled scramjet configuration. The experiments were conducted at a freestream Mach number of 7.3 and a total flow enthalpy of 4.3MJ/kg corresponding to a Mach 9.7 flight condition. The phenomenon of radical-farming has been studied in detail using two-dimensional OH* chemiluminescence imaging and emission spectroscopy. High signal levels of excited OH (OH*) were detected behind the first shock reflections inside the combustion chamber upstream of any measurable pressure rise from combustion, which occurred towards the rear of the combustor. The production of OH in the first hot pocket initiates the ignition process and then accelerates the combustion process in the next downstream hot pocket. This was confirmed by numerical simulations of premixed hydrogen/air flow through the scramjet. Chemical kinetics analyses reveal that the ignition process is governed by the interaction between various reaction groups leading to a chainbranching explosion for low mean temperature and pressure combustion flowfields.
Resumo:
Emission spectroscopy was used to investigate ignition and combustion characteristics of supersonic combustion ramjet engines. Two-dimensional scramjet models with inlet injection, fuelled with hydrogen gas, were used in the study. The scramjet engines were configured to operate in radical farming mode, where combustion radicals are formed behind shock waves reflected at the walls. The chemiluminescence emission signals were recorded in a two-dimensional, time-integrated fashion to give information on the location and distribution of the radical farms in the combustors. High signal levels were detected in localised regions immediately downstream of shock reflections, an indication of localised hydroxyl formation supporting the concept of radical farming. Results are presented for a symmetric as well as an asymmetric scramjet geometry. These data represent the first successful visualisation of radical farms in the hot pockets of a supersonic combustor. Spectrally resolved measurements have been obtained in the ultraviolet wavelength range between 300 and 400 nm. This data shows that the OH! chemiluminescence signal around 306nm is not the most dominant source of radiation observed in the radical farms.
Resumo:
The use of dual growing rods is a fusionless surgical approach to the treatment of early onset scoliosis (EOS) which aims to harness potential growth in order to correct spinal deformity. This study compared through in-vitro experiments the biomechanical response of two different rod designs under axial rotation loading. The study showed that a new design of telescoping growing rod preserved the rotational flexibility of the spine in comparison with rigid rods indicating them to be a more physiological way to improve the spinal deformity.
Resumo:
ATTENDANCE IN HIGH -QUALITY early childhood education and care (ECEC) has been shown to have a positive influence on young children’s development and life chances, especially for those children from disadvantaged backgrounds. A number of government policies are in place, both internationally and in Australia, to support these children’s use of ECEC services. But to what extent do Australia’s most vulnerable children use ECEC? Drawing on data from Growing up in Australia: The longitudinal study of Australian children (LSAC) this paper demonstrates that children from a range of disadvantaged groups do use ECEC. However, based on more in-depth analyses using a Disadvantage Index, the paper also shows that children with multiple indicators of disadvantage were more likely to be in exclusive parental care, less likely to be using preschool and using fewer hours of care than their peers. These findings suggest that there may be barriers to ECEC utilisation for children and families for whom ECEC potentially has the most benefit.
Resumo:
Designing systems for multiple stakeholders requires frequent collaboration with multiple stakeholders from the start. In many cases at least some stakeholders lack a professional habit of formal modeling. We report observations from student design teams as well as two case studies, respectively of a prototype for supporting creative communication to design objects, and of stakeholder-involvement in early design. In all observations and case studies we found that non-formal techniques supported strong collaboration resulting in deep understanding of early design ideas, of their value and of the feasibility of solutions.
Resumo:
Early childhood education has long been connected with objectives related to social justice. Australian Early Childhood Education and Care (ECEC) has its roots in philanthropic and educational reform movements prevalent at the turn of the 20th century. More recently, with the introduction of the National Early Childhood Reform Agenda, early childhood education has once more been linked to the achievement of aims associated with redressing inequality and disadvantage. According to Jean-Marie, Normore and Brooks (2009), educational leaders have a moral and social obligation to foster equitable practices through advocating for traditionally marginalised and poorly served students while creating a new social order “...that subverts the long standing system that has privileged certain students while oppressing or neglecting others” (p.4). Drawing on extant literature, including data from two previously reported Australian studies in which leadership emerged as having a transformational impact on service delivery, this paper examines the potential of early childhood leadership to generate ‘socially just’ educational communities. With reference to critical theory, we argue that critically informed, intentional and strategic organisational leadership can play a pivotal role in creating changed circumstances and opportunities for children and families. Such leadership includes positional and distributed elements, articulation of values and beliefs, and collective action that is mindful and informed.
Resumo:
Student engagement in the delivery of theoretical course materials is a current challenge in the tertiary sector including for dietetic training. In 2011 with the creation of a new nutritionist position for Queensland Meals on Wheels (QMOW), a service learning approach to support this organisation was used with third year dietetic students undertaking two days of structured activities at various QMOW sites in South East Queensland, aligned with coursework in Foodservice Management (FSM). This cohort of students was then followed in their final year post successful completion of five weeks professional practice in FSM to see if this experience supported readiness for placement and competency development. Evaluation was undertaken of eligible students (n = 50) via paper based survey (response rate 94%) with all participating in targeted focus groups. Findings showed that students acknowledged the QMOW experience (on reflection 14 months later) providing opportunity for participation and/or observation in 5 of 12 FSM areas taught in third year, including food safety, meal production, assembly, delivery and dishwashing. Over half the students identified good exposure to FSM competency areas during the QMOW experience, with 83% satisfied with their competency exposure and subsequent practice during final year placements. A consistent theme emerged from focus groups supporting inclusion of practical opportunities with the theoretical component of the FSM subject to highlight relevance to learning. These findings highlight the importance of such teaching initiatives to met student learning preferences, linking theory with practice and supporting competency development in the final year of training programs.
Resumo:
The mechanical microenvironment at a fracture site could potentially influence the outcomes of bone fracture healing. It is known that, should the fixation construct be too stiff, or the gap between the fracture ends be too large, bones are less likely to heal. Flexible fixation or so-called “biological fixation” has been shown to encourage the formation of fracture callus, and therefore result in better healing outcomes. However, till date the nature of the relationship between the degree of mechanical stability provided by a flexible fixation and optimal healing fracture healing outcomes has not been fully understood. This paper presents a computational model that can predict healing out-comes from early stage healing data under various fixation configurations. The results of the simulations demonstrate that the change of mechanical microenvironment of fracture site resulting from the different fixation configurations is of importance for the healing outcomes.
Resumo:
Tissue engineering and cell implantation therapies are gaining popularity because of their potential to repair and regenerate tissues and organs. To investigate the role of inflammatory cytokines in new tissue development in engineered tissues, we have characterized the nature and timing of cell populations forming new adipose tissue in a mouse tissue engineering chamber (TEC) and characterized the gene and protein expression of cytokines in the newly developing tissues. EGFP-labeled bone marrow transplant mice and MacGreen mice were implanted with TEC for periods ranging from 0.5 days to 6 weeks. Tissues were collected at various time points and assessed for cytokine expression through ELISA and mRNA analysis or labeled for specific cell populations in the TEC. Macrophage-derived factors, such as monocyte chemotactic protein-1 (MCP-1), appear to induce adipogenesis by recruiting macrophages and bone marrow-derived precursor cells to the TEC at early time points, with a second wave of nonbone marrow-derived progenitors. Gene expression analysis suggests that TNFα, LCN-2, and Interleukin 1β are important in early stages of neo-adipogenesis. Increasing platelet-derived growth factor and vascular endothelial cell growth factor expression at early time points correlates with preadipocyte proliferation and induction of angiogenesis. This study provides new information about key elements that are involved in early development of new adipose tissue.
Resumo:
Designing systems for multiple stakeholders requires frequent collaboration with multiple stakeholders from the start. In many cases at least some stakeholders lack a professional habit of formal modeling. We report observations from two case studies of stakeholder-involvement in early design where non-formal techniques supported strong collaboration resulting in deep understanding of requirements and of the feasibility of solutions.