1000 resultados para marginal impacts


Relevância:

20.00% 20.00%

Publicador:

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.

Relevância:

20.00% 20.00%

Publicador:

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.

Relevância:

20.00% 20.00%

Publicador:

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.

Relevância:

20.00% 20.00%

Publicador:

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.

Relevância:

20.00% 20.00%

Publicador:

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.