Steriel of niet steriel, dat is de vraag

Summary  This paper deals with a practical problem of sampling inspection, viz. the bacterial control of imported fishmeal (which is used in food for pigs). It was suspected that this fishmeal was often contaminated by salmonella-bacteria, but only in about 0.5% of the samples the presence of these bacteria could be proved. An investigation by the Dutch National Institute of Public Health, at which 4 bags of fishmeal (about 50 kg) after homogenization were divided into 1000 samples of 50 grams each which were individually tested on the presence of salmonella bacteria, showed that nothwithstanding the homogenization the bacteria were very irregularly distributed. Every bag was contaminated, but only about 1.8% of the samples were infected. So the density of infection was low, but the fraction of infected bags was high.
If the fishmeal were fed in a dry condition to the pigs the relevant parameter on which the condition of the fishmeal should be judged would have been the mean number of bacteria per gram of fishmeal. However, as food for pigs is mixed with water the bacteria have the possibility to increase in number so the relevant parameter to judge a batch of fishmeal is the fraction of non-sterile bags.
At the end of this paper a sampling scheme is given, including a system of penalty for producers who regularly supply contaminated fishmeal which will in a relative short time improve the quality of the imported fishmeal.     

An analysis of the cost of providing ancillary services to skilled nursing facility patients in New York State

Currently, nursing homes can arrange for the provision of ancillary services either by providing the services directly, purchasing the services through contracts and fees, or by outside billings, in which the services are supplied by other providers who then bill Medicaid directly. Frequently, some combination of these three modes of provision is used for each ancillary service. The purpose of this study is to explore ancillary costs in a sample of nursing homes and to determine, to the extent possible, the most cost-efficient means of providing selected ancillary services (physical therapy, radiology and medical staff services). Prior to examining the impact of the mode of provision on cost levels, other facility and patient characteristics that might justifiably affect costs are identified and adjusted for. The results demonstrate that outside billing or purchasing services can be much less expensive than providing the services directly. It is suggested that all ancillary services (outside billings as well as services provided directly through contracts and fees) be included when facility-to-facility cost comparisons are made. This approach should serve as an incentive for nursing homes to seek the most cost-efficient means of providing ancillary services.     

Highway traffic flow and the uneconomic region of production

In this paper highway traffic flow is formulated as a short-run production function in which traffic volume is the output and traffic density is the variable input. Given this formulation, the ‘uneconomic’ region of production is relevant. Often it is the case that traffic density will exceed the point at which traffic volume is at a maximum; i.e., the marginal product of the variable input is negative.     

The determinants and effects of actual,abandoned and contested mergers

This paper reports the results of research aimed at exploring why some takeover bids give rise to merger while other do not and, using as a basis of comparison matched samples of actual and abandoned mergers, the performance effects of mergers. In this work, 50 cases of abandoned mergers occurring between 1965 and 1975 were analysed against a matched sample of 50 actual mergers. In addition, 33 cases of contested bids were also analysed. Variables used reflected managerial, shareholder and financial strength considerations. Analysis covered a period three years before to three years after each bid. Techniques of analysis were differences of means and discriminant analysis. The results show that there are important differences between target companies that are acquired and those that successfully resist takeover bids. They also show the influence of managerial and financial variables as the key to a successful takeover bid rather than variables reflecting shareholder interests. Analysis of the effects of the outcome of the bids suggests that companies involved in abandoned mergers recorded a stronger performance over the subsequent 1–3 years than those that made acquisitions, especially where shareholder and financial considerations are concerned. Target companies that resisted takeover bids showed a significant performance improvement.     

Contributions to nonparametric generalized failure rate function estimation

For a specified distribution functionG with densityg, and unknown distribution functionF with densityf, the generalized failure rate function (x)=f(x)/gG ^–1 F(x) may be estimated by replacingf andF byf _n and , wheref _n is an empirical density function based on a sample of sizen from the distribution functionF, and . Under regularity conditions we show and, under additional restrictions whereC is a subset ofR and _n. Moreover, asymptotic normality is derived and the Berry-Esséen type bound is shown to be related to a theorem which concerns the sum of i.i.d. random variables. The order boundO(n^–1/2+c _n ^1/2 ) is established under mild conditions, wherec _n is a sequence of positive constants related tof _n and tending to 0 asn.Research was supported in part by the Army, Navy and Air Force under Office of Naval Research contract No. N00014-76-C-0608. AMS 1970 subject classifications. Primary 62G05. Secondary 60F15.     

The booster function and the entrepreneurial quality: an application to the province of Seville

The objectives of this paper are two-fold. First, to elaborate a theoretical model that shows the characteristics of an entrepreneur of quality and the factors that influence them. Second, to apply the model to entrepreneurs in the province of Seville, one of the least developed areas in the European Union. The purpose is to show the importance of entrepreneurship for business success and, more importantly, in economic development. In summary, the model shows that entrepreneurs of quality possess an intrinsic motivation and, as consequence of this, they adopt some energizer behaviours, such as the capacity for innovation, ambition and co-operation with others. The model also takes into account factors that influence these characteristics, including the personal context of the entrepreneur, such as experience, education and family, and the global context, such as productive opportunities, socio-cultural factors and political-institutional factors. In the analysis of the entrepreneurs of Seville, the paper mainly focuses on the motivation and the energizer behaviours and their interdependence. The empirical findings indicate that the model is valid.