Truncated sequential sign tests for location shift

A truncated sequential sign test for location shift is studied when the null or target location has been estimated from a prior, fixed sample. If the randomness of the target is ignored then the test is shown to be strongly anticonservative, the degree being proportional to the ratio of the truncation point to the fixed sample size. The test is distribution-free under the hypothesis of no shift enabling exact Type I errors and null expected samples sizes to be calculated and compared to a modified Brownian motion approximation. A Monte Carlo power study shows that the test compares favorably with thr test against a Xnown target. An abbreviated table of critical values is given.     

Automatic processes and the appraisal of sexual stimuli: Toward an information processing model of sexual arousal

A model of sexual arousal is presented that highlights the interaction between automatic and controlled cognitive processes and proposes that different levels of cognitive processing can differentially affect subjective and physiological sexual arousal. In addition, two studies are presented in which the role of automatic processes was explored using a priming paradigm. Subjects were sexually functional men. In the first study an effect of priming was found on penile erection. Unexpectedly, responses were lower in sexual than in neutral trials. In the second study support was found, using a behavioral measure (decision time), for the notion that the meaning of sexual stimuli can be perceived in a fast, automatic manner. Priming was most successful at lower levels of stimulus accessibility. The model and experimental approach presented in this article render starting points for new research on response discordance, gender differences in the processing of sexual stimuli, and inhibition of sexual response.     

Two Graphical Techniques Useful in Detecting Correlation Structure in Repeated Measures Data

Analysis of repeated measures data using a mixed model includes specifying a form for the covariance matrix of the within-subject observations. This reduction in the number of estimated parameters from the unspecified structure may improve the efficiency of inferences made. An implementation of this technique has been incorporated in the MIXED procedure of the SAS® statistical package, and includes a wide range of options for the structure of the covariance matrix. It is demonstrated that draftman's display plots and/or plots in a coordinate system with parallel axes can aid in visualizing the dispersion structure.     

Siting Samplers to Minimize Expected Time to Detection

We present a probabilistic approach to designing an indoor sampler network for detecting an accidental or intentional chemical or biological release, and demonstrate it for a real building. In an earlier article, Sohn and Lorenzetti developed a proof of concept algorithm that assumed samplers could return measurements only slowly (on the order of hours). This led to optimal “detect to treat” architectures that maximize the probability of detecting a release. This article develops a more general approach and applies it to samplers that can return measurements relatively quickly (in minutes). This leads to optimal “detect to warn” architectures that minimize the expected time to detection. Using a model of a real, large, commercial building, we demonstrate the approach by optimizing networks against uncertain release locations, source terms, and sampler characteristics. Finally, we speculate on rules of thumb for general sampler placement.     

Chemistry of growth medium and leachate from green roof systems in south-central Texas

Installation of intensive and extensive green roofs is becoming popular for reducing runoff from impervious surfaces in many cities around the world. Most studies on runoff quality from green roofs have been conducted in cooler northern climates. We examined the losses and gains of nutrients, cations and selected anions in planted and unplanted growth medium and compared these to initial growth medium (IGM) typically used for green roof modules in south-central Texas. Water extracts of growth medium and leachate from three replicates of unplanted growth medium and three planted species (Sedum kamtschaticum, Delosperma cooperi and Talinum calycinum) were examined. During the first 6 months after establishment we observed high losses of nitrate (25 to 44 mg kg⁻¹), dissolved organic carbon (DOC: 155 to 190 mg kg⁻¹) and nitrogen (DON: 9.0 to 11.2 mg kg⁻¹) and orthophosphate-P (1 to 2 mg kg⁻¹). Average leachate concentrations based on four rain events 6 months after establishment ranged from 0.3 to 6.6 mg L⁻¹ in planted modules and 6.3 mg L⁻¹ in unplanted modules for nitrate-N, 38 to 42 mg L⁻¹ in planted modules and 32 mg L⁻¹ in unplanted modules for DOC, 2.1 to 3.1 mg L⁻¹ in planted modules and 2.1 mg L⁻¹ in unplanted modules for DON and 0.27 to 0.37 mg L⁻¹ in planted modules and 0.40 mg L⁻¹ in unplanted modules for orthophosphate-P. We suggest that after the establishment of green roofs, leachate losses may contribute some runoff concentrations of nitrogen, carbon and phosphorous in urban areas.