Monitoring the extent and occurrence of fire in the different veld types of South Africa with particular reference to its ecological role and role in range management

The author has identified the following significant results. Veld burning was recorded from LANDSAT imagery covering approximately 75 million ha or 62% of the surface of the eastern part of South Africa. All basic data on the location, areas, and numbers of burns for 10 biomes, composed of 67 veld types, are available on 1:250,000 and 1:500,000 map overlays, and are summarized on small scale maps showing fire distribution and amount burned in classes per 15 minute square of latitude and longitude. Veld burning is not randomly distributed, but is almost continuous over a broad belt, widest in the north and narrowing southeastwards, and then southwestwards between the eastern escarpment and the area. It is shown that over almost the whole sea, the overall pattern of veld burning is clearly marked out as early as July in midwinter, subsequent development being merely an intensification of the pattern

Monitoring the extent and occurence of fire in the different veld types of South Africa with particular reference to it's ecological role

The author has identified the following significant results. Imagery showed the highest amount of burned area to be in the western, southern, and eastern Transvaal and in one scene of the Transkei coast region. The percentage of burned area per image in all instances exceeded 1.4% reaching a maximum of 8.24% equivalent to 121,758 ha out of 1,476,540 ha of one image in the eastern Transvaal lowveld. There was a consistent increase in the amount of burnt area on images from July through to the end of October. From October onwards, there was a decrease in burned area so that during December there was none or very little burning evident. Four scenes comprising nine images showed burning according to the twelve veld types. Considerable variation was evident in the burning between different veld types: between 10 and 19% of the mixed, sourish-mixed, and sour bushveld types was burnt, but in other veld types the percentage of burnt area was less than 1%

The use of the implied standard deviation as a predictor of future stock price variability: A review of empirical tests

Estimation;Securities;mathematische statistiek

Veld condition indexing : relevance to wildlife management?

Rangelands (veld) form part of an important renewable resource. · Measurement and monitoring of veld condition is an important management tool. Management methods need to be centred on the objectives of the livestock farm or game reserve being managed. Veld condition assessments and their use in managing stocking rates are dependent on the range succession model, which sets out the concept of directional successional changes in species composition. Although this rangeland succession model has been widely criticised it is still extensively used for veld management in South Africa. Many variations of veld condition assessment methods have been developed to be used as a tool for making informed management decisions. The Ecological Index Method was the focus of this study. The general expectation of the relationship between veld condition and animal biomass is that the greatest biomass should be in areas of high veld condition. Soil condition and habitat structure were also explored in terms of their relationship with the veld condition index. Animal biomass was found to decrease slightly with increasing veld condition index scores. There was little to no relationship between VCI and species diversity and evenness. Herbivore species displayed a range of habitat preferences in terms of VCI scores, grass height and tree basal area. This indicated that habitat choices may not have only been influenced by forage quality but also by ability to graze different grass heights, based on jaw morphology, and the risk of predation. The relationship between VCI and veld condition variables was found to be triangular due to the method of calculation causing the VCI to fold back on itself. This complicates interpretation of results. The results of this study suggest that either the interpretation of the index needs to be reconsidered for a game reserve context or a new method needs to be developed

Specification of multiparty audio and video interaction based on the Reference Model of Open Distributed Processing

The Reference Model of Open Distributed Processing (RM-ODP) is an emerging ISO/ITU-T standard. It provides a framework of abstractions based on viewpoints, and it defines five viewpoint languages to model open distributed systems. This paper uses the viewpoint languages to specify multiparty audio/video exchange in distributed systems. To the designers of distributed systems, it shows how the concepts and rules of RM-ODP can be applied.\ud \ud The ODP ¿binding object¿ is an important concept to model continuous data flows in distributed systems. We take this concept as a basis for multiparty audio and video flow exchanges, and we provide five ODP viewpoint specifications, each emphasising a particular concern. To ensure overall correctness, special attention is paid to the mapping between the ODP viewpoint specifications

QUEST II. A multi country business cycle and growth model. Economic Papers No. 123, October 1997. II/509/97-EN

From the Introduction. QUEST was designed to analyse the economies in the member states of the European Union and their interactions with the rest of the world, especially with the United States and Japan. The focus of the model is on the transmission of the effects of economic policy both on the domestic and the international economy. The model was primarily constructed to serve as a tool for policy simulation; less emphasis was put on its ability to serve as a forecasting tool. Given the wide coverage of the model it must necessarily be highly aggregated. A high degree of aggregation and foundation of the specification in current macroeconomic theory also helps in interpreting and understanding the results of the simulations. Finally simplicity also facilitates the solution of the model and reduces the time and memory requirements of the computer-simulations. The new model contains structural models for the EU member states, the US and Japan and distinguishes 10 additional countries/regions in trade feedback models in order to model trade interactions with the rest of the world

What drives executive stock option backdating?

We study motives for executive stock option backdating, the practice of changing the grant dates of current options to dates in the past using hindsight. We find that smaller, younger, and less profitable firms tend to be heavier involved in backdating. These results are consistent with the retention hypothesis. In line with the incentive hypothesis, we find that backdating occurs more for options that are out-of-the-money. We derive some evidence for the agency hypothesis, in the sense that backdating companies have a larger percentage of inside directors. However, contrary to this hypothesis, we conclude that backdating firms have better protection for minority shareholders compared to firms that do not backdate

Do Spin-offs really Create Value? The European Case

We study wealth effects for a sample of 161 spin-offs from 15 different European countries that were announced between January 1987 and September 2000. The cumulative average abnormal return over the three-day event window is 2.35%. The mean abnormal return is 2.89% for companies that increase their industrial focus and only 1.20% for non-focus increasing companies.These results are in line with previous studies for the United States.The long-run returns in excess of the market return are significantly negative for both parent and pro-forma combined firms.However, if we control for the size and book-to-market effects by creating a matching portfolio, we find mostly insignificant long-run excess returns both for focus-increasing and non-focus increasing parents, subsidiaries and pro-forma combined firms.This result suggests that, unlike U.S. spin-offs, European spin-offs are not associated with long-run outperformance.return on investment;spin-offs