Maximum likelihood estimation of variance components in a completely random bib design

ABSTRACT

The purposes of this paper are to abstract from a number of articles variance component estimation procedures which can be used for completely random balanced incomplete block designs, to develop an iterated least squares (ITLS) computing algorithm for calculating maximum likelihood estimates, and to compare these procedures by use of simulated experiments. Based on the simulated experiments, the estimated mean square errors of the ITLS estimates are generally less than*those for previously proposed analysis of variance and symmetric sums estimators.     

Brown rats (<Emphasis Type="Italic">Rattus norvegicus</Emphasis>) in urban ecosystems: are the constraints related to fieldwork a limit to their study?

Nowadays, the majority of human beings live in urban ecosystems, with this proportion expected to continue increasing in the future. With the growing importance of urban rat-associated issues (e.g. damages to urban infrastructures, costs of rat-control programs, rat-associated health risks), it is becoming indispensable to fill the identified gaps in knowledge on the urban brown rat regarding, among others, its density, home range, genetic structure, and infectious status. In this context, live-trapping is a crucial prerequisite to any scientific investigation. This paper assesses the main constraints and challenges regarding the urban field and describes the major steps to be considered when planning research on urban rats. The primary challenges are i) the characterization of the urban experimental unit; ii) the choice of a trapping design: the use of live-trapping in capture-mark-recapture design, in association with modern statistics, is highly recommended to answer ecological questions (although these methods, mostly developed in natural ecosystems, need to be implemented for the urban field); iii) the potential ethical considerations with regard to animal welfare and field-worker safety; iv) the building of mutually-beneficial collaborations with city stakeholders, pest control professionals, and citizens. Emphasis must be put on communication to the public and education of field-workers. One major need of modern urban rat research is a peer-validated field methodology allowing reproducibility, repeatability, and inference from urban field studies and enabling researchers to answer long-standing key questions about urban rat ecology.     

Road socialism

Road socialists maintain that government is the best manager for the nation's vehicular transportation arteries. Contrary to their views, the present author maintains that the managerial role can best be fulfilled by private entrepreneurs. Under highway privatization, he claims, traffic fatalities and automobile congestion will be sharply reduced.The author wishes to thank the North American Editor of Transport Policy, and an anonymous referee from the present journal, for helpful suggestions and commentary on an earlier draft of this paper.     

Opportunity sets and individual well-being

 An opportunity set ranking rule assigns an ordering of opportunity sets to each individual utility function (defined on the universal set of alternatives) within the domain of this rule. Using an axiomatic approach, this paper characterizes a general class of opportunity set ranking rules which are based on the utilities associated with the elements of an opportunity set. It is argued that the addition of an alternative to a given opportunity set is not necessarily desirable in terms of overall well-being, and this position is reflected in replacing a commonly used monotonicity axiom with an alternative condition. Received: 15 May 1995/Accepted: 14 December 1995     

The career of the mentally ill: an integration of psychiatric, labeling/social construction, and lay perspectives

This paper provides a new way of conceptualizing the career of the mentally ill. Most persons who experience an episode of a serious mental disturbance lead a normal life, while a few persons lead lifetimes that revolve around their mental disorders. The processes leading to either result can only be understood by integrating the traditional labeling and psychiatric perspectives with lay understandings of the concepts of "mental illness" and "nervous breakdowns." A selection of key concepts from these perspectives leads to a better understanding of the different paths persons take as they move through the pre-patient, inpatient, and post-patient phases of the "career of the mentally ill." This perspective makes understandable a number of counterintuitive relationships. For example, it explains why most hospitalized mental patients (1) have a negative stereotype of the "mentally ill," (2) do not perceive themselves as "mentally ill, yet (3) perceive themselves as benefiting from treatment, and (4) do not progress into a career of secondary deviance.     

Commodity price stabilization models: A review and appraisal

This paper is designed to bring into focus the numerous modeling attempts to analyze commodity price stabilization that have recently appeared. The studies examined begin with the Waugh-Oi-Massell framework and advance to econometric commodity modeling. Such a critique is considered necessary: None of the studies examined has overcome the myriad of problems that analysts have pointed out as essential for assessing the welfare outcomes of price stabilization schemes. As a consequence, stabilization analyses for similar commodities have produced conflicting results regarding predicted welfare outcome. The present appraisal attempts to provide a unity of direction to this work by (1) comparing recieved studies of a theoretical, empirical, and econometric modeling nature, and (2) suggesting possibilities for improving modeling analyses.     

Ten years of business planners

This paper sets out some of the traps that planners are heir to in describing archetypal planners. The author then cites the pitfalls for the planner and suggests that ideally his role is that of the guiding light of the enterprise, a signpost pointing the way at a cross-roads or correcting a wrong turning, and illuminating the way ahead. This planner is the true helpmate of the chief executive.     

The art and science of winning physician support for Six Sigma change

Active physician participation and acceptance of Six Sigma is critical to successful implementation. Take a look at strategies and techniques that can help secure physician support for Six Sigma.