21st century fisheries management: a spatio-temporally explicit tariff-based approach combining multiple drivers and incentivising responsible fishing

Abstract Kraak, S. B. M., Reid, D. G., Gerritsen, H. D., Kelly, C. J., Fitzpatrick, M., Codling, E. A., and Rogan, E. 2012. 21st century fisheries management: a spatio-temporally explicit tariff-based approach combining multiple drivers and incentivising responsible fishing. – ICES Journal of Marine Science, 69: 590–601. Traditionally fisheries management has focused on biomass and mortality, expressed annually and across large management units. However, because fish abundance varies at much smaller spatio-temporal scales, fishing mortality can potentially be controlled more effectively if managed at finer scale. The ecosystem approach requires more indicators at finer scales as well. Incorporating ecosystem targets would need additional management tools with potentially conflicting results. We present a simple, integrated, management approach that provides incentives for “good behaviour”. Fishers would be given a number of fishing-impact credits, called real-time incentives (RTIs), to spend according to spatio-temporally varying tariffs per fishing day. RTI quotas and tariffs could be based on commercial stocks and ecosystem targets. Fishers could choose how to spend their RTIs, e.g. by limited fishing in high-catch or sensitive areas or by fishing longer in lower-catch or less sensitive areas. The RTI system does not prescribe and forbid, but instead allows fishers to fish wherever and whenever they want; ecosystem costs are internalized and fishers have to take them into account in their business decisions. We envisage no need for traditional landings or catch quotas for the fleets while operating under the scheme. The approach could facilitate further devolution of responsibility to industry.</jats:p

Homo loquens en homo scribens

Dutch and Flemish language; Philosophy; Psycholog

Concussion knowledge and attitudes amongst Stellenbosch University hostel rugby players

Background: Concussion occurs more frequently in contact sports, such as rugby, and is furthermore not fully recognised during play. It is also underreported in the literature, to medical personnel, or to coaches.Objectives: The objective of this study was to describe the knowledge about and attitudes towards concussion by Stellenbosch University hostel rugby players.Methods: The study focussed on gathering quantitative information through implementing a cross-sectional study design. One hundred and eighty Stellenbosch University hostel rugby players completed the modified Rosenbaum Concussion Knowledge and Attitudes Survey - Student Version (RoCKAS-ST). The RoCKAS-ST questionnaire is divided into three parts, namely, the evaluation of the Concussion Knowledge Index (CKI) and Concussion Attitudes Index (CAI), and a 16-symptom checklist.Results: The participants scored on average 75% in the CKI and 81% in the CAI. The correlation between CKI and CAI was r=0.14 which is considered a weak positive correlation.Discussion: The participants demonstrated sufficient knowledge of concussion and thus a safer attitude towards concussion. There were some concerning factors from the knowledge of the concussion questions and the symptoms that may have an effect on attitudes towards concussion.Conclusion: The study revealed that Stellenbosch University hostel rugby players have sufficient knowledge of what constitutes concussion, as well as the necessity of having safe attitude towards it. However, a small number of participants showed that they still may lack knowledge in certain areas concerning concussion.Keywords: head injuries; hostel league; university level rugby; surve

Cyclotron resonance of the quasi-two-dimensional electron gas at Hg1-xCdxTe grain boundaries

The magnetotransmission of a p-type Hg0.766Cd0.234Te bicrystal containing a single grain boundary with an inversion layer has been investigated in the submillimetre wavelength range. For the first time the cyclotron resonance lines belonging to the various electric subbands of a quasi-two-dimensional carrier system at a grain boundary could be detected. The measured cyclotron masses and the subband densities determined from Shubnikov-de Haas experiments are compared with theoretical predictions and it is found that the data can be explained very well within the framework of a triangular well approximation model which allows for non-parabolic effects

GeoVisual analytics: interactivity, dynamics, and scale

3D desktop-based virtual environments provide a means for displaying quantitative data in context. Data that is inherently spatial in three-dimensions may benefit from visual exploration and analysis in relation to the environment in which they were collected and to which they relate. We empirically evaluate how effectively and efficiently such data can be visually analyzed in relation to location and landform in 3D versus 2D visualizations. In two experiments, participants performed visual analysis tasks in 2D and 3D visualizations and reported insights and their confidence in them. The results showed only small differences between the 2D and 3D visualizations in the performance measures that we evaluated: task completion time, confidence, complexity, and insight plausibility. However, we found differences for different data sets and settings suggesting that 3D visualizations, or 2D representations respectively, may be more or less useful for particular data sets and contexts

Towards a developmental state? Provincial economic policy in South Africa

This paper explores the meaning of the developmental state for spatial economic policy in South Africa. Two main questions are addressed: do provincial governments have a role to play in promoting economic prosperity, and to what extent do current provincial policies possess the attributes of a developmental state? These attributes are defined as the ability to plan longer term, to focus key partners on a common agenda, and to mobilise state resources to build productive capabilities. The paper argues that the developmental state must harness the power of government at every level to ensure that each part of the country develops to its potential. However, current provincial capacity is uneven, and weakest where support is needed most. Many provinces seem to have partial strategies and lack the wherewithal for sustained implementation. Coordination across government appears to be poor. The paper concludes by suggesting ways provincial policies could be strengthened