Valuing entrepreneurial investments: the venture capitalists' approach.

Valuing high-growth, high-uncertainty firms, characterised by a unique business concept, significant growth opportunities, and/or no real positive cash flows to show the profit potential of the venture, is a major challenge faced by most venture capitalists (Gompers (1995)). Unlike for an investment in publicly traded securities for which there exists a well-defined pricing mechanism, it is difficult to find an objective valuation for the investment holdings of a venture capital fund. The valuation of individual unquoted investments is, thus, a very complicated process. subject to the discretion and judgment from the part of the venture capitalist. Recently, growing criticism and increasing interest are observed regarding the valuation of the private equity and venture capital portfolios of high-tech, high risk, high growth venture investments (EVCA (2001), Millner (2002), Blaydon & Horvath (2002)). Consequently, the underlying goal of the empirical analyses included in this paper corresponds exactly with revealing the valuation methodology operated by venture capitalists when determining or reconsidering the valuation for each venture investment held in portfolio.Cash flow; Firms; Investment; Investment portfolio; Investments; Opportunities; Portfolio; Pricing; Processes; Risk; Studies; Valuation; Valuation method; Venture capital;

Determination of the resolution limit of a whole body PET scanner using monte carlo simulations

We studied the resolution limit that can be obtained for a whole body PET scanner. The results were obtained using a Monte Carlo based simulation program. The influence of two parameters was investigated: the crystal pixel size and the number of layers used for Depth-Of-Interaction (DOI) correction

Knowledge of Bovine Tuberculosis, Cattle Husbandry and Dairy Practices amongst Pastoralists and Small-Scale Dairy Farmers in Cameroon

BACKGROUND:Control of bovine tuberculosis (bTB) and zoonotic tuberculosis (zTB) has relied upon surveillance and slaughter of infected cattle, milk pasteurisation and public health education. In Cameroon, like many other sub-Saharan African countries, there is limited understanding of current cattle husbandry or milk processing practices or livestock keepers awareness of bTB. This paper describes husbandry and milk processing practices within different Cameroonian cattle keeping communities and bTB awareness in comparison to other infectious diseases. STUDY DESIGN:A population based cross-sectional sample of herdsmen and a questionnaire were used to gather data from pastoralists and dairy farmers in the North West Region and Vina Division of Cameroon. RESULTS:Pastoralists were predominately male Fulanis who had kept cattle for over a decade. Dairy farmers were non-Fulani and nearly half were female. Pastoralists went on transhumance with their cattle and came into contact with other herds and potential wildlife reservoirs of bTB. Dairy farmers housed their cattle and had little contact with other herds or wildlife. Pastoralists were aware of bTB and other infectious diseases such as foot-and-mouth disease and fasciolosis. These pastoralists were also able to identify clinical signs of these diseases. A similar proportion of dairy farmers were aware of bTB but fewer were aware of foot-and-mouth and fasciolosis. In general, dairy farmers were unable to identify any clinical signs for any of these diseases. Importantly most pastoralists and dairy farmers were unaware that bTB could be transmitted to people by consuming milk. CONCLUSIONS:Current cattle husbandry practices make the control of bTB in cattle challenging especially in mobile pastoralist herds. Routine test and slaughter control in dairy herds would be tractable but would have profound impact on dairy farmer livelihoods. Prevention of transmission in milk offers the best approach for human risk mitigation in Cameroon but requires strategies that improved risk awareness amongst producers and consumers

Valuation and reporting requirements faced by venture capitalists

nrpages: 29status: publishe

Valuing entrepreneurial investments: the venture capitalists' approach

Valuing high-growth, high-uncertainty firms, characterised by a unique business concept, significant growth opportunities, and/or no real positive cash flows to show the profit potential of the venture, is a major challenge faced by most venture capitalists (Gompers (1995)). Unlike for an investment in publicly traded securities for which there exists a well-defined pricing mechanism, it is difficult to find an objective valuation for the investment holdings of a venture capital fund. The valuation of individual unquoted investments is, thus, a very complicated process. subject to the discretion and judgment from the part of the venture capitalist. Recently, growing criticism and increasing interest are observed regarding the valuation of the private equity and venture capital portfolios of high-tech, high risk, high growth venture investments (EVCA (2001), Millner (2002), Blaydon & Horvath (2002)). Consequently, the underlying goal of the empirical analyses included in this paper corresponds exactly with revealing the valuation methodology operated by venture capitalists when determining or reconsidering the valuation for each venture investment held in portfolio.status: publishe

Influence of detector pixel size, TOF resolution and DOI on image quality in MR-compatible whole-body PET

The optimization of a whole-body PET system remains a challenging task, as the imaging performance is influenced by a complex interaction of different design parameters. However, it is not always clear which parameters have the largest impact on image quality and are most eligible for optimization. To determine this, we need to be able to assess their influence on image quality. We performed Monte-Carlo simulations of a whole-body PET scanner to predict the influence on image quality of three detector parameters: the TOF resolution, the transverse pixel size and depth-of-interaction (DOI)-correction. The inner diameter of the PET scanner was 65 cm, small enough to allow physical integration into a simultaneous PET-MR system. Point sources were used to evaluate the influence of transverse pixel size and DOI-correction on spatial resolution as function of radial distance. To evaluate the influence on contrast recovery and pixel noise a cylindrical phantom of 35 cm diameter was used, representing a large patient. The phantom contained multiple hot lesions with 5 mm diameter. These lesions were placed at radial distances of 50, 100 and 150 mm from the center of the field-of-view, to be able to study the effects at different radial positions. The non-prewhitening (NPW) observer was used for objective analysis of the detectability of the hot lesions in the cylindrical phantom. Based on this analysis the NPW-SNR was used to quantify the relative improvements in image quality due to changes of the variable detector parameters. The image quality of a whole-body PET scanner can be improved significantly by reducing the transverse pixel size from 4 to 2.6 mm and improving the TOF resolution from 600 to 400 ps and further from 400 to 200 ps. Compared to pixel size, the TOF resolution has the larger potential to increase image quality for the simulated phantom. The introduction of two layer DOI-correction only leads to a modest improvement for the spheres at radial distance of 150 mm from the center of the transaxial FOV