23,325 research outputs found
Overview of the subsonic propulsion technology session
NASA is conducting aeronautical research over a broad range of Mach numbers. In addition to the generic and high speed propulsion research, the Lewis Research Center is continuing its substantial efforts towards propulsion technology for a broad range of subsonic flight applications. Reviewed here are some of the elements of that program, including small engine technology, rotorcraft, icing research, hot section technology, and the Advanced Turboprop Project
Citizen Science in Disaster and Conflict Resilience
*Background/Question/Methods*

Within the disaster and conflict response communities, concern about lack of effectiveness of outside responses has led to a debate about the role of local people in developing the capacity to prepare for a crisis and to respond after calamity has struck. Pelling (2007) points out the potential for participatory disaster risk assessment to build local capacity and for generating knowledge that, along with more expert-driven data collection, is used to identify and reduce the risk of disaster. Similarly, Weinstein and Tidball (2007) and Tidball et al. (2008) present an alternative model for post-crisis intervention based on local assets, including ongoing attempts of communities to manage their natural resources. For example, these authors suggest that civic ecology (CE) practices, including community forestry, watershed enhancement, community agriculture and gardening, and other participatory environmental restoration initiatives that emerge from the actions of local residents (Tidball and Krasny 2007), should be examined and perhaps leveraged by outsiders for their ability to mitigate post-crisis situations. The question is, how might CE relate to citizen science in applications post-disaster or conflict?

*Results/Conclusions*

CE practices emerge through the actions of people wanting to manage a local resource, and integrate both learning through small-scale experimentation and observations (adaptive management) and collaborative or participatory processes (co-management). They can be considered as an emergent form of adaptive co-management (Ruitenbeek and Cartier 2001; Armitage, Plummer et al. 2009). The local knowledge of individuals who initiate the practices is critical, although often linkages are made with scientists from universities, government, and non-profit organizations, so multiple forms of knowledge are incorporated into the stewardship activities. This learning shortens feedback times between management actions, such as participatory approaches for planting trees, and seeing the impact of tree planting on local ecological and social systems. CE practices embody attributes that may foster resilience both prior to and post-crisis, including multiple forms of knowledge and governance, self-organization, adaptive learning, shorter feedbacks, and ecosystem services (Folke, S. Carpenter et al. 2002; Walker and Salt 2006). We demonstrate that similar to CE, citizen science could build capacity to mitigate disaster and conflict through shortening feedbacks and through making available multiple forms of knowledge and data collection. Further, given the need for asset-based and participatory interventions post-crisis, and the paucity of existing mechanisms that address this need (Weinstein and Tidball 2007), we examine citizen science and its potential to become part of a tool kit of participatory responses that engage citizens in meaningful activity post-conflict
Outcomes based education? Rethinking the provision of compulsory education in Western Australia
Outcomes based education (OBE), which emphasises a radical reinterpretation of the enterprise of education, is a phenomenon enveloping the Australian compulsory education sector. This paper examines the theoretical tenets of OBE as articulated by its chief exponent, William Spady. It then explores the effects that OBE implementation is having on the Western Australian educational fraternity, touching upon current tensions and emerging consequences. Implementation exigencies in one area of the WA curriculum (Mathematics) are then considered; and finally, possible future ‘outcomes’ are suggested should the identified concerns fail to receive due attention
Grouping & regrouping using Mixintools: An exploratory study
On a regular basis, teachers find it necessary to place children into groups for instruction. Random assignment is typically the norm when group composition is immaterial to the task. When member-sensitive groups need to be created, teachers might associate specific assignment with colours, numbers or other coding systems. Mixintools offers the teacher a strategy for creating groups in an enjoyable, expedient and variable fashion. Or does it? The purpose of this research was to determine whether the resource had any value from the perspective of both the teacher and the student. Data were sourced from three primary schools and one university teacher education class regarding the usefulness of Mixintools. Results indicated a mixed response. Reasons for this are reported
Limitation of Trypanosoma brucei parasitaemia results from a combination of density-dependent parasite differentiation and parasite killing by the host immune response
In the bloodstream of its mammalian host, the "slender" form of Trypanosoma brucei replicates extracellularly, producing a parasitaemia. At high density, the level of parasitaemia is limited at a sublethal level by differentiation to the non-replicative "stumpy" form and by the host immune response. Here, we derive continuous time equations to model the time-course, cell types and level of trypanosome parasitaemia, and compare the best fits with experimental data. The best fits that were obtained favour a model in which both density-dependent trypanosome differentiation and host immune response have a role in limiting the increase of parasites, much poorer fits being obtained when differentiation and immune response are considered independently of one another. Best fits also favour a model in which the slender-to-stumpy differentiation progresses in a manner that is essentially independent of the cell cycle. Finally, these models also make the prediction that the density-dependent trypanosome differentiation mechanism can give rise to oscillations in parasitaemia level. These oscillations are independent of the immune system and are not due to antigenic variation
Maverick Examples Of Coset Conformal Field Theories
We present coset conformal field theories whose spectrum is not determined by
the identification current method. In these ``maverick'' cosets there is a
larger symmetry identifying primary fields than under the identification
current. We find an A-D-E classification of these mavericks. }Comment: 16pages , reportSWAT-93-0
Treeless vegetation of the Australian Alps
Based on 1222 floristic quadrat samples, 56 plant communities were identified in treeless vegetation in the Australian Alps of south-eastern Australia. (c. 35º 30´–38ºS, 146°–149°E). The study encompassed vegetation from above the upper limit of trees on mountain tops (i.e. the truly alpine environment) and below the inverted treeline in subalpine valleys. Generally, grasslands develop on deep humus soils, heathlands occur on shallower or rocky soils, and wetland communities are found in places of permanent or intermittent wetness. Duration of snow cover, lithology, altitude and exposure are also important determinants of the spatial arrangement of communities. Broadly, communities within a geographic region are more closely related to each other than to communities of similar structure or dominants from other geographic areas. Many communities are either very localised or are widespread with a small area of occupancy. Fourteen communities are probably eligible for listing as threatened, either alone or as aggregates with associated communities. A total of 710 native taxa from 82 families has been recorded. There is a high level of endemism – 30% of taxa are ± restricted to treeless vegetation in the Australia Alps and a further 14% are ± restricted to treeless vegetation but occur in mountain areas outside the Australian mainland (e.g. Tasmania and New Zealand). Thirteen taxa are listed in the Environment Protection and Biodiversity Conservation Act 1999 as threatened and a further 18 taxa are identified that may be eligible for listing as threatened nationally. 131 non-native taxa have been recorded in natural vegetation. Treeless vegetation has been intensively utilised since European settlement, initially as summer pastures for cattle and sheep but more recently as water catchments for electricity production and as tourist attractions both in winter and summer. Many communities are slowly recovering from past pressures and from the fires of 2003, which burnt most of the area for the first time since 1939. The treeless vegetation of the Australian Alps faces an uncertain future because of increased pressure from tourism and the unknown impacts of global warming
The Influence of Reservoir Basin Morphometry on Phytoplankton Community Structure
The research protocol was designed to compare three reservoirs with similar physical environments but different morphometry. Three reservoirs on the western edge of the Ozark uplift were selected because of their similar substrate and climatic condition. The reservoirs primarily differed in morphometry. Two of the reservoirs were of identical size, Bob Kidd and Prairie Groves Lakes, but of different configuration, semicircular and linear, respectively. The bifurcated lake, Lincoln Lake, was of smaller size. Each lake is dimictic. Each of the lakes were nitrate-N limited while soluble reactive phosphorus-P is available and not restricting the growth of phytoplankton. Although the pattern of nutrient utilization was similar among the nutrient concentrations varied. Phytoplankton succession was alike in each reservoir but differed in quantity
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