999 resultados para Oblique Impacts
Resumo:
Adjustments to gait were examined when positioning the foot within a narrow target at the end of an approach for two impact conditions, hard and soft. Participants (6 M, 6 F) ran toward a target of three lengths along a 10-m walkway consisting of two marker strips with alternating black and white 0.5-m markings. Five trials were conducted for each target length and impact task, with trials block randomized between the 6 participants of each gender. A 50-Hz digital video camera panned and filmed each trial from an elevated position adjacent to the walkway. Video footage was digitized to deduce the gait characteristics. A linear speed/accuracy tradeoff between target length and approach time was found for both impact tasks (hard, r = 0.99, p < 0.01; soft, r = 0.96, p < 0.05). For the hard-impact task, visual control time increased linearly (r = 0.99, p < 0.05) when whole-body approach velocity decreased. Visual control time was unaffected by whole-body approach velocity in the soft-impact task. A constant tau-margin of 1.08 describes the onset of visual control when approaching a target while running, with the control of braking during visual control described by a tau-dot of –0.85. Further research is needed to examine the control of braking in different targeting tasks.
Resumo:
This paper reports on the use of an online, resource-based learning (RBL) approach in first year psychology at Deakin University. Differences between on- and off-campus students that emerged are examined in the context of the learning goals and study approaches of the two student groups and their attitudes to using computers. Unlike the on-campus students who were less positive about working with computers and reported confusion about how and what to study for the unit, the off-campus students reported feeling confident they had a good study strategy and were more positive about computers. The off-campus students also reported that they spent more time working with electronic resources and attached greater value to them. While all students valued the prescribed resources, the off-campus students found some of the optional, electronic resources valuable because they added to the learning experience. These students also reported greater use of the computer-mediated communication available as part of the online learning environment, and valued this functionality more highly than did the on-campus students. These findings highlight the need to take into account learner characteristics when designing learning environments that cater for individual differences and preferences. While online-supported RBL approaches have the potential to cater to the diverse needs of students, learning environments need to be designed, structured and delivered so the learning experience can be customized to the needs of different student cohorts, while preserving the overarching, pedagogical goals.
Resumo:
Asia dominates global aquaculture production accounting for over 80% of the total and the mainstay in Asian aquaculture is finfish. Over the years, Asia has experienced a number of inter-continental and intra-continental transfers/introductions/translocation of finfish species, between nations and watersheds, beyond their natural range of distribution, primarily for aquaculture development. In this article all such species are referred to as alien species. An attempt is made to evaluate the importance of the production of alien species in selected Asian nations, using statistics of the Food and Agriculture Organization. Also, negative effects, if any, based on literature surveys, of alien species in relation to displacement of indigenous species, and on biodiversity and/or genetic diversity together with associated pathogen transfers are evaluated. The major alien species, based on their significance to Asian inland aquaculture considered, are the tilapias, catfish, Chinese and Indian major carps and common carp. It is estimated that currently alien species account for nearly 12% of the cultured finfish production (2.6 million tonnes) in Asia, valued at US$ 2.59 billion, and the contribution exceeds 40% when Asian countries excluding China are taken into consideration. Inland finfish aquaculture in some Asian nations, such as Indonesia and the Philippines, is predominated by alien species, and in some others, e.g. Bangladesh and India, the contribution from alien species has been increasing steadily. It is suggested that overall alien finfish species have done little ecological harm to native flora and fauna. However, in the wake of increasing anthropogenic development taking place in watersheds the resulting environments are often made unconducive to indigenous species but not to some alien species, thereby potentially and indirectly making the latter invasive.
Resumo:
Wastewater reuse is being widely promulgated to help address the global freshwater resource crisis. It can assist in reducing extraction of freshwater from the environment, and reuse of wastewater lessens the need for environmental discharge, which is clearly beneficial to receiving waters. But the practice itself also has the potential to be detrimental to natural and human environments: soil structure can become degraded, aquifers may be polluted, and human health may be threatened. The challenge facing natural resource managers is to identify the potential benefits and risks, and to achieve an appropriate balance. This paper describes environmental benefits and threats concomitant with the reuse of wastewater. We frequently draw upon examples from China and Australia-two countries that face particularly daunting water resource
challenges-but the principles can be.extended far beyond these geographical bounds and are applicable to
many parts of the world.
Resumo:
This paper examines how the adoption of a system's perspective to the use of both marketed and public resources can be incorporated into an analysis of productivity measurement. A biophysical model is used to measure the environmental inputs which are combined with conventional marketed inputs to develop a Malmquist Productivity Index to determine social productivity growth over the perios under study. The analysis is applied to data collected from selected farms in south west Victoria and includes a measure of leaching and run-off as a proxy measure of the impact the application of fertilizers has on ground and surface water. Although the sample is small, the results show measured productivity growth differs when environmental factors are considered.
Resumo:
Monitoring Ecological Impacts provides the tools needed to design assessment programs that can reliably monitor, detect and allow management of human impacts on the natural environment. The procedures described are well-grounded in inferential logic. Step-by-step guidelines and flow diagrams provide clear and useable protocols, which are applicable to real situations.
Resumo:
Sewage effluent is a powerful agent of ecological change in estuaries. While the effects of sewage pollution on water quality are usually well documented, biological responses of exposed organisms are not. We quantified health impacts in the form of pathological tissue changes across multiple organs in estuarine fish exposed to elevated levels of treated wastewater. Structural pathologies were compared in wild populations of four fish species from two subtropical estuaries on the east coast of Australia that differ substantially in the amount of direct wastewater loadings. Uptake of sewage-derived nitrogen by fish was traced with stable nitrogen isotopes. Pathologies were common in the liver, spleen, gill, kidney and muscle tissues, and included granulomas, melanomacrophage aggregates, and multiple deformities of the gill epithelia. Tissue deformities were more frequent in fish exposed directly to wastewater discharges. Mullet (Valamugil georgii) were most affected, with only a single specimen free of pathologies in the sewage-impacted estuary. Similarly, in those fish that had structural abnormalities, more deformities were generally found in individuals from sites receiving sewage. These spatial contrasts in impaired fish health correspond to significantly enriched δ15N values in fish muscle as a consequence of fish assimilating sewage-N. Overall, the pattern of lower health and enriched δ15N values in fish from sewage-impacted areas suggests that organism health is lowered by sewage inputs to estuaries. Measurements of organism health are required to understand the effects of sewage on estuarine ecosystems, and histopathology of fishes is a powerful tool to achieve this.
Resumo:
This paper addresses knowledge management (KM) in a project management organisation through a case study. The case study organisation is a small- edium sized Taiwanese-owned construction company (staff size of approximately 50) with an annual turnover of approximately TWD50 (AUD$1.85) billion. Approximately one half of the company comprised project-related staff (e.g. construction project management, project documentation, estimation, procurement, and design), while the other comprised administrative and business-related staff (e.g. office administration and management, business development, and finance and accounting). The researcher undertook a series of surveys and one-on-one interviews whilst ‘embedded’ for several months with the organisation. As part of a larger research project, this case study was one of four case studies conducted in major construction organisations in Singapore, Taiwan, and Australia. The study revealed the recognition, importance and commitment of organisational culture to KM, and the effects the knowledge management initiatives have on the organisation’s ability to manage knowledge across its projects and deliver the projects at various ‘levels’ of the organisation (individual, project, departmental, and corporate). It concludes that a technologically and functionally sound KM infrastructure does not necessarily assure an organisation with a capability to manage knowledge. Organisations need to ensure that the KM repository is made up of quality and relevant contents (not just quantity), and that corporate culture (especially the willingness of individuals to share what they know) is a critical determining factor to the organisation’s ability to share, apply and create knowledge (i.e. low sharing capability leads to low application and creation capabilities).
Resumo:
The Genuine Progress Indicator (GPI) is estimated as if nations operate within a closed economy. Therefore, in terms of coverage, the GPI is most analogous to Gross Domestic Product (GDP). Indeed, within the relevant literature, these two indicators are most often contrasted. However, consideration should be given to adapting the GPI, so it has more in common with Gross National Income (GNI). As with GDP, the GPI is concerned only with a particular physical location. Yet, it may be more effective if the GPI was freed from these physical boundaries in a similar manner to GNI. The GPI should be concerned more with the 'ownership' of the costs and benefits associated with economic growth than with the 'location' of those costs and benefits. Those that derive the most benefit from exploitation of the environment are often physically removed from the location of that damage. The GPI does not consider the net consumers of the negative externalities of environmental costs, merely the producers. Currently, however, the structure of the GPI allows a nation to enjoy, without penalty, the benefits of importing goods from countries which bear a disproportionately large cost of environmental degradation. This results in an overstatement of the real progress experienced by the county importing 'dirty goods'. This paper will investigate how certain GPI adjustments may be adapted to overcome this present shortcoming. However, the purpose of this paper is not only to empirically implement this new approach, but also to stimulate debate as to its potential merit.
Resumo:
There has been much research on the subject of environmentally sustainable design (ESD), with emerging techniques and technologies improving rapidly and informing sustainability higher education teaching to architects and prospective architects. By examining the success of sustainable designs using post occupancy evaluations, architectural practices might also increase their knowledge of sustainable building practice. Post occupancy evaluations could be useful for improving the designs of future buildings and the design processes that generated them. This paper aims to evaluate these claims by asking: "Do sustainable design practices use the feedback gained from post occupancy evaluations?," "How does the feedback refine the design process?," "How is the information gained in these evaluations absorbed within the firm's design practices?," and, "Does the size of a practice impact on its implementation and
dissemination of POE?" This paper investigates the questions posed above through the questioning of architectural practices that have gained a reputation for environmentally sustainable design by having a strong sustainable design philosophy and/or by being recognised for this by winning a sustainability design award. The interviewed practices will have provided some form of post occupancy evaluation as a service or employed them to add to their own knowledge.