Bayesian MARS

A Bayesian approach to multivariate adaptive regression spline (MARS) fitting (Friedman, 1991) is proposed. This takes the form of a probability distribution over the space of possible MARS models which is explored using reversible jump Markov chain Monte Carlo methods (Green, 1995). The generated sample of MARS models produced is shown to have good predictive power when averaged and allows easy interpretation of the relative importance of predictors to the overall fit.     

Semiparametric Efficient Estimation in the Generalized Odds-Rate Class of Regression Models for Right-Censored Time-to-Event Data

The generalized odds-rate class of regression models for time to event data is indexed by a non-negative constant and assumes thatg(S(t|Z)) = (t) + Zwhere g(s) = log(^-1(s-) for > 0, g₀(s) = log(- log s), S(t|Z) is the survival function of the time to event for an individual with qx1 covariate vector Z, is a qx1 vector of unknown regression parameters, and (t) is some arbitrary increasing function of t. When =0, this model is equivalent to the proportional hazards model and when =1, this model reduces to the proportional odds model. In the presence of right censoring, we construct estimators for and exp((t)) and show that they are consistent and asymptotically normal. In addition, we show that the estimator for is semiparametric efficient in the sense that it attains the semiparametric variance bound.     

Campaigning against female genital mutilation in Ethiopia using popular education

In Ethiopia, the Italian Association for Women in Development (AIDOS) has been working with Ethiopia's National Committee on Traditional Practices Affecting the Health of Women and Children for 5 years. AIDOS began working on female genital mutilation in the early 1980s and rejects charges of cultural imperialism that are applied to Northern organizations attempting to help African organizations address this violation of universal human rights. In Ethiopia, 85% of women are mutilated, with most undergoing Sunna, or removal of the prepuce of the clitoris. The joint project seeks to increase awareness about the health consequences of female genital mutilation in the target group. The primary technique used is provision of training of trainers courses and presentation of four modular units and audiovisual materials specifically designed for use with socially influential women, male and female secondary school students, community leaders, and health workers. In addition, an information/education campaign uses videos and sound and slide shows with accompanying story books. A second category of communication tools was developed for a mass information campaign, including radio spots, posters, information leaflets, and a newsletter. When the project was ready for expansion into the southern region of the country, it became clear that a new participatory communication strategy was required to stimulate discussion, such as the use of role playing and theater. Working together, the two organizations have successfully confronted project constraints such as the difficulty in assessing project impact, scheduling problems, and gender-biased assess to information.     

What turns you on and off?

When you are exploring your career and where you are headed, it is helpful to consider what aspects of your job turn you on, and of course, those that don't. Energizers are activities that excite and invigorate you or people who lift your heart and inspire you. De-energizers are activities or people who drain you, drag you down, depress you. Make lists of those things that energize and de-energize you either at work or in other situations. Try hard to do something to incorporate or change at least the first five on each list and see if you feel more job and life satisfaction. Responses from 30 participants of a recent Career Choices program are provided to help you get started.     

Making the health care delivery system accountable.

Accountability has become the fact of life for the health care provider and the delivery system. Until recently, accountability has been viewed primarily through the judicial process as issues of fraud and liability, or by managed care entities through evaluation of the financial bottom line. It is this second consideration and its ramifications that will be explored in this article. Appropriate measurement tools are needed to evaluate services, delivery, performance, customer satisfaction, and outcomes assessment. Measurement tools will be considered in light of the industry's unique considerations and realities. All participants, including insurers, employers, management, and health care providers and recipients, bear responsibilities which necessitate assessment and analysis. However, until the basic question, "Who is the customer?" is resolved, accountability issues remain complex and obscured. Accountability costs and impacts must be evaluated over time. They go way beyond bottom line cost containment and reduction. Accountability will be accomplished when the health care industry implements quality and measurement concepts that yield the highest levels of validity and appropriateness for health care delivery.     

AIDS in China

Although 10,676 people were officially reported to be infected with HIV on China's mainland by the end of June 1998, experts estimate that more than 300,000 Chinese are actually infected with HIV in China. They also believe HIV continues to spread in alarming fashion. Two thirds of reported HIV infection cases live in rural China, and nearly one third of the 301 people diagnosed as having AIDS have died. About 10% of all HIV infections occurred among teenagers under age 19 years old, with most infected through IV drug use. 60% of teens who responded to a survey in 1997 did not possess correct basic knowledge about AIDS, and 21% did not know how to protect themselves from contracting HIV.     

Strong minimum energy hierarchical topology in wireless sensor networks

Given a set of \(n\) sensors, the strong minimum energy topology (SMET) problem in a wireless sensor network is to assign transmit powers to all sensors such that (i) the graph induced only using the bi-directional links is connected, that is, there is a path between every pair of sensors, and (ii) the sum of the transmit powers of all the sensors is minimum. This problem is known to be NP-hard. In this paper, we study a special case of the SMET problem, namely , the \(k\)-strong minimum energy hierarchical topology (\(k\)-SMEHT) problem. Given a set of \(n\) sensors and an integer \(k\), the \(k\)-SMEHT problem is to assign transmission powers to all sensors such that (i) the graph induced using only bi-directional links is connected, (ii) at most \(k\) nodes of the graph induced using only bi-directional links have two or more neighbors, that is they are non-pendant nodes, and (iii) the sum of the transmit powers of all the sensors in \(G\) is minimum. We show that \(k\)-SMEHT problem is NP-hard for arbitrary \(k\). However, we propose a \(\frac{k+1}{2}\)-approximation algorithm for \(k\)-SMEHT problem, when \(k\) is a fixed constant. Finally, we propose a polynomial time algorithm for the \(k\)-SMEHT problem for \(k=2\).     

Entrepreneurial orientation in vertical alliances: joint product innovation and learning from allies

This paper clarifies how a firm’s entrepreneurial orientation (EO) affects joint product innovation within a vertical alliance and how this is influenced by increasing technological uncertainty and the absorption of knowledge from the alliance partners. The results of a structural equation model with latent interactions on 171 firms in the manufacturing industry indicate that the focal firm’s EO increases joint innovation, although this positive effect declines when a high level of uncertainty increases. On the other hand, the ability to absorb partners’ knowledge increases joint product innovation. As such, this study’s results contribute to research in the field of vertical alliances, EO, and the theoretical foundation of a dynamic capability perspective.