Modelling growth and decline in lung function in Duchenne's muscular dystrophy with an augmented linear mixed effects model

Summary.  Longitudinal modelling of lung function in Duchenne's muscular dystrophy is complicated by a mixture of both growth and decline in lung function within each subject, an unknown point of separation between these phases and significant heterogeneity between individual trajectories. Linear mixed effects models can be used, assuming a single changepoint for all cases; however, this assumption may be incorrect. The paper describes an extension of linear mixed effects modelling in which random changepoints are integrated into the model as parameters and estimated by using a stochastic EM algorithm. We find that use of this 'mixture modelling' approach improves the fit significantly.     

The Balance Point: Keeping Serial Bibliographic Records Viable in a Digital Age

Michael Norman, head of serials cataloging at University of Illinois at Urbana-Champaign (UIUC) library, describes his library's development of an integrated management system for serials, the Online Research Resources (ORR). The ORR was designed to draw together and deliver to the public a wide range of information related to the library's serial holdings that previously could only be obtained by consulting a number of sources. With a single search, UIUC patrons can now consult the ORR for serials information such as variant titles, online availability, subject categories, print summary statements, ISI impact factor, where the title is indexed, and whether it is peer reviewed—an innovation sorely needed and highly welcomed by librarians and patrons alike.     

Tables to facilitate fitting lu distributions

This paper is concerned with estimating the parameters of Tadikamalla-Johnson's L_Udistributions based on the method of moments. Tables of the parameters of the L_U distribution are given for selected values of skewness (0.0(0.05) 1.0(0.1)2.0) and for twenty values of kurtosis at intervals of 0.2. The construction and use of these tables is explained with a numerical example.     

The Secret Downing Street Memo,the One Percent Doctrine,and the Politics of Truth: A Performance Text

Presented to the Society for the Study of Symbolic Interaction in Montreal, Canada, on August 7, 2006, this performance text is a critique of the Bush administration and its reliance on science, or evidence‐based models of inquiry (SBR). SBR raises issues concerning the politics of truth and evidence. These issues intersect with the ways in which a given political regime fixes facts to fit ideology. Three versions of SBR are discussed. A model of science as disruptive cultural practice is outlined. I locate the interactionist project in the discourses surrounding the global war on terror and the war in Iraq. I conclude by calling for a merger of critical pedagogy with a prophetic, feminist postpragmatism.     

Percentage points and power calculations for outlier tests in a regression situation

The usefulness of an extra sum of squares statistics Q_K for detecting K outliers has been discussed previously in the context of two-way tables. (See Gentleman and Wilk, 1975a, 1975b; John and Draper 1978; and Draper and John, 1980,) That work is extended here to straight line regression situations arising from, and motivated by, a specific set of research data. Percentage points for the appropriate test statistics are obtained by simulation, and approximations for these percentage points are suggested. Power calculations made for various designs and outlier situations are briefly summarized.     

Ecological Community Structure Analyses in the Formulation,Implementation, and Enforcement of Law and Policy

Most of what is currently known about ecosystems derives from two sources: comprehensive studies by classical ecologists and economically motivated studies by resource specialists. The former have traditionally concentrated on natural or long-undisturbed ecosystems, the latter on those few species in managed or polluted ecosystems that are harvested, hunted, or fished. A recent genre of legislation, drafted with insight provided by the scientific community, recognizes the dearth of ecological information on managed or polluted communities (which are becoming far more ubiquitous and important) and dramatically raises the requirements for comprehensive data and data analyses to guide managerial and pollution abatement policies. This paper describes several important current efforts to use ecological community structure analyses to implement and enforce such legislation and some effects of such analyses on environmental policy.