Bayesian MCMC Mapping of Quantitative Trait Loci in a Half-sib Design: a Graphical Model Perspective

Graphical models provide a powerful and flexible approach to the analysis of complex problems in genetics. While task-specific software may be extremely efficient for any particular analysis, it is often difficult to adapt to new computational challenges. By viewing these genetic applications in a more general framework, many problems can be handled by essentially the same software. This is advantageous in an area where fast methodological development is essential. Once a method has been fully developed and tested, problem-specific software may then be required. The aim of this paper is to illustrate the potential use of a graphical model approach to genetic analyses by taking a very simple and well-understood problem by way of example.     

The Returns to Academic and Vocational Qualifications in Britain

This paper uses data from the 1991 sweep of the National Child Development Study (NCDS) and the 1998 Labour Force Survey (LFS) to provide a comprehensive analysis of the labour market returns to academic and vocational qualifications. The results show that the wage premia from academic qualifications are typically higher than from vocational qualifications. However, this gap is reduced somewhat, when we control for the amount of time taken to acquire different qualifications. This is particularly important for vocational courses, which generally take shorter time periods to complete. In the paper we also investigate how returns vary by gender, subsequent qualifications, and the natural ability of individuals. Finally, by comparing the NCDS results with those from the LFS, we estimate the bias that can result from not controlling for factors such as ability, family background and measurement error. The results reveal that the estimated returns in the NCDS equations controlling for ability, family background and measurement error are similar to the simple OLS estimates obtained with the LFS, which do not control for these factors. This suggests that the biases generally offset one another.     

Some Cracks in the Empire of Chance (Flaws in the Foundations of Reliability)

Making quantified statements about the uncertainty associated with the lifelength of an item is one of the most fundamental tasks of reliability assessment. Most practitioners routinely do this using one of the several available statistical techniques. The purpose of this paper is two-fold. The first is to give the user an overview of the key tenets of two of the most commonly used parametric approaches. The second is to point out that these commonly used approaches involve strategies that are either ad hoc, or are in violation of some of the underlying tenets. A method that is devoid of logical flaws can be proposed, but this method is difficult to implement. The user must therefore resign to using that technique against which the fewest objections can be hurled.     

Scaling up support for children in HIV-affected families by involving early childhood development workers: community views from KwaZulu-Natal,South Africa

The United Nations Programme on HIV/AIDS estimates that South Africa has 1.2 million orphans as a result of AIDS. This study investigated the views of communities in KwaZulu-Natal on the potential use of early childhood development (ECD) practitioners for helping children in vulnerable households. It reports on in-depth interviews and focus group discussions with community members and service providers in six different areas of KwaZulu-Natal. Despite the increase in the numbers of deaths, people in affected areas have yet to accept that HIV is the cause. Stigma, denial, myths and witchcraft beliefs were evident, particularly in the rural areas. There was general agreement by the respondents that ECD practitioners with additional training specific to HIV/AIDS could assist families if cost difficulties were overcome. As community members with basic training in childcare they could enhance community responses by linking with community health workers and other service providers to assist children and households in need.     

A theory of innovation for process-based innovations such as nanotechnology

Many see Nanotechnology as the technology that will underlie the next Schumpeterian wave creating new opportunities for wealth and job creation. Further it is a process based or materials technology. Yet all currently used models of innovation are based on assembled products or service products and these simply do not recognize the differences in materials products nor the “enabling” nature of Nanotechnologies. If nanotechnology is poised to become the economic engine of this millennium and if current models of innovation, which are utilized, by policy makers and firm based strategist alike are based on technology product paradigms that are dissimilar to the realities of nanotechnology and other process-based technologies then there is cause for concern.Here the authors provide a model and supporting cases demonstrating a new process or materials based innovation model that is based on the tight coupling between product and process innovation of not only Nanotechnology-based products but other process-based products. This is an important finding, because it identifies and remedies a gap in the literature associated with earlier process and product innovation models. For process-based products like materials, food, chemicals and nanotechnologies any change to the manufacturing processes results in significant changes in end product features. The implications of this model to practice are considered.     

Issues Facing Small Accounting Practices in Regional North Queensland: An Exploratory Study

Small accounting practices (SAP), most of which are sole principals, are an important part of the accounting profession and the Australian economy. This exploratory study identifies issues and challenges experienced by small accounting principals in Far North Queensland, Australia. The findings generally correspond with previous research, ranking staffing and keeping up to date through professional development as key areas of concern, and also highlighting the expectation gap between SAP principals and their clients. Stress emerged as a major concern for principals, and new areas of possible conflict of interests were uncovered. A number of potential areas for future research, including comparative studies in city and suburban areas, have been identified.     

Dividend Imputation and Shareholder Wealth: The Case of New Zealand

On April 1, 1988, New Zealand stopped the double taxation of dividends by implementing a full dividend imputation program. Because many believed that the tax advantage of debt had led to more highly leveraged firms subject to greater financial risk than was socially optimal, it was hoped the removal of incentives to finance with debt would result in a more efficient allocation of capital. The empirical results suggest that the shareholder wealth gain from dividend imputation was more than offset in firms with large debt levels. Moreover, an examination of debt ratios indicates debt levels declined in the post–imputation period.