Optimal Diversity in Investments with Recombinant Innovation

The notion of dynamic, endogenous diversity and its role in theories of investment and technological innovation is addressed. We develop a formal model of an innovation arising from the combination of two existing modules with the objective to optimize the net benefits of diversity. The model takes into account increasing returns to scale and the effect of different dimensions of diversity on the probability of emergence of a third option. We obtain analytical solutions describing the dynamic behaviour of the values of the options. Next diversity is optimized by trading off the benefits of recombinant innovation and returns to scale. We derive conditions for optimal diversity under different regimes of returns to scale. Threshold values of returns to scale and recombination probability define regions where either specialization or diversity is the best choice. In the time domain, when the investment time horizon is beyond a threshold value, a diversified investment becomes the best choice. This threshold will be larger the higher the returns to scale.

Lenticular Galaxies and Their Environments

It is widely believed that lenticular (S0) galaxies were initially spirals from which the gas has been removed by interactions with hot cluster gas, or by ram-pressure stripping of cool gas from spirals that are orbiting within rich clusters of galaxies. However, problems with this interpretation are that: (1) Some lenticulars, such as NGC 3115, are isolated field galaxies rather than cluster members. (2) The distribution of flattening values of S0 galaxies in clusters, in groups and in the field are statistically indistinguishable. This is surprising because one might have expected most of the progenitors of field S0 galaxies to have been flattened late-type galaxies, whereas lenticulars in clusters are thought to have mostly been derived from bulge-dominated early-type galaxies. (3) It should be hardest for ram-pressure to strip massive luminous galaxies with deep potential wells. However, no statistically significant differences are seen between the luminosity distributions of early-type Shapley-Ames galaxies in clusters, groups and in the field. (4) Finally, both ram-pressure stripping and evaporation by hot intra-cluster gas would be most efficient in rich clusters. However, the small number of available data in the Shapley-Ames sample appears to show no statistically significant differences between the relative frequencies of dust-poor S0_1 and dust-rich S0_3 galaxies in clusters, groups and in the field. It is tentatively concluded that ram-pressure stripping, and heating by intra-cluster gas, may not be the only evolutionary channels that lead to the formation of lenticular galaxies. It is speculated that gas starvation, or gas ejection by active nuclei, may have play a major role in the formation of a significant fraction of all S0 galaxies.Comment: Astrophysical Journal, in pres

Clinical salmonellosis in a finishing herd, a case report

In a finishing herd of 1020 head clinical salmonellosis was a problem in market age pigs during 2002. During two years, intervention and prevention was done using organic acids through drinking water and feed. Progress of the Salmonella-status was monitored by detecting antibodies against Salmonella. From this case it can be concluded that clinical salmonellosis disappeared and dead loss decreased rapidly after application of the acids. The mean OD% dropped strongly from 40 to below 10. The herd never became entirely Salmonella-free, defined as no samples with OD%\u3e10. The sickbay was a problem location because it was not operated on an all-in/all-out basis. Infection levels differed strongly between stables and compartments. The outbreak in the third quarter of 2002 cost on average 4.60 per pig delivered to the abattoir in that period. The majority of the costs of clinical salmonellosis are due to a reduction of technical results

Measuring the Economic Value of Two Habitat Defragmentation Policy Scenarios for the Veluwe, The Netherlands

This paper offers an economic value assessment of a nature protection programme in the Veluwe. This programme involves two defragmentation scenarios: the first scenario connects the central part of the Veluwe with the IJssel river forelands in a north-eastern direction, while the second scenario is focused on defragmentation in a south-western direction, where the Rhine river forelands are located. The valuation is based on a questionnaire that was administered during face-to-face interviews in the Veluwe area and through the Internet. We employ a contingent valuation approach to assess the respondents’ willingness to pay for the realisation of the defragmentation scenarios. It appears that the mean willingness to pay for the two defragmentation scenarios are € 59.7 and € 162.2 per respondent. These two willingness-to-pay estimates, which refer to a lump sum payment (or ‘once-and-for-all payment’), are based on a lognormal and Weibull distribution respectively. In addition to the willingness to pay, we also estimate recreation benefits of the Veluwe. To that end, we use the travel cost technique, the purpose of which is to arrive at an estimate of the site’s consumer surplus. According to this technique, the yearly recreational benefits are estimated between € 0.06 and € 0.45 per visitor. Whereas the former estimate is based on the fuel costs only, the latter covers also insurance and maintenance costs, and capital depreciation. Finally, we performed an aggregation of individual WTP estimates over Dutch households. With the resulting aggregate estimates we are able to compare the total costs and benefits of the two scenarios for habitat fragmentation in the Veluwe. The result of such a simple comparison turns out to critically depend on whether the mean or median estimate is used for aggregation. If aggregation of individual WTP estimates is based on mean values, then the benefits far exceed the estimated costs of defragmentation. In other words, based on an integrated economic-ecological analysis it makes sense to execute the defragmentation measures described in the scenarios. However, aggregate estimates obtained by using median values result in higher costs than aggregate estimates that are based on mean values. Even stronger, median-based estimates show that the costs of implementing scenario 2 are higher than the total benefits of this scenario.Economic value, Nature protection, Defragmentation policy, Veluwe

Winners and losers : the evolution of consumer spending mix as emerging markets mature

Selling to emerging consumers is no small challenge, especially when a multinational is unfamiliar with a country’s distinctive consumer terrain. The objective of this research was to inform decision-makers in multinationals and domestic firms seeking investment opportunities to grow volume and margins in emerging markets. Consumer spending trends and economic data were analysed in order to assist companies to identify products and service categories (“winners”) to compete in within selected emerging markets. A literature review was followed by quantitative analysis of consumer spending trends in seventeen emerging markets selected from low-income, middle-income and upper-middle-income economies, as classified by the World Bank. Visual representation and inspection, as well as descriptive statistics of the data, were followed by statistical analysis. The paired sample t-test, the Wilcoxon test and stepwise regression techniques were used to test the research questions. The findings suggest that the services category, specifically education and medical services, gained significant share of consumer spending. The durable goods category share remained flat and generic “losers” emerged mainly from the non-durable goods and semi-durable goods sub-categories. It seems as though few generic winners and losers exist and that a country-by-country analysis needs to be conducted.Dissertation (MBA)--University of Pretoria, 2010.Gordon Institute of Business Science (GIBS)unrestricte

The missionary character of Paul's stay on Malta (Acts 28:1-10) according to the early Church

Paul's apparent lack of preaching to the inhabitants of Malta in Acts 28:1-10 and his seeming indifference to being called 'a god' form a stark contrast to his usual missionary pattern in the narrative of Acts, possibly showing a lack of evangelistic concern among the 'barbarian' population of the island. This article investigates the reception of Acts 28:1-10 in the writings of the Greek- and Latin speaking church (up to the end of the fifth century) to determine whether Paul's behaviour in Acts 28:1-10 was considered to be missionary in character. This proves to be the case, although the missionary nature of his actions is substantiated in a variety of ways.http://journals.sabinet.co.za/ej/ejour_patris.htmlam201

The distinction between story and discourse in the analysis of biblical narrative

The distinction between story and discourse has become all but canonical in narratology. This article investigates the viability of this approach with reference to the narratological analysis of biblical narratives. It is shown that the distinction is indeed necessary, although the traditional approach should be modified. Discourse, rather than story, should be the starting point of any narratological analysis. This leads to the concept of an “implied story, which can be used as an analytical tool in the analysis of narrative. Special attention is given to the application of this new approach to biblical narrative, with an example drawn from a comparison of Isa 36:1-22 and 2 Kgs 18:13-37.This article is a revised version of a chapter of the author’s thesis submitted to the Ancient Languages Department of the University of Pretoria in partial fulfillment of the requirements for the MA degree in Ancient Languages and Cultures. The study was supervised by Prof. G T M Prinsloo.http://www.sun.ac.za/jnslhttp://upetd.up.ac.za/thesis/available/etd-11202008-180028/nf201