Conditional Spectral Analysis of Replicated Multiple Time Series with Application to Nocturnal Physiology

This article considers the problem of analyzing associations between power spectra of multiple time series and cross-sectional outcomes when data are observed from multiple subjects. The motivating application comes from sleep medicine, where researchers are able to non-invasively record physiological time series signals during sleep. The frequency patterns of these signals, which can be quantified through the power spectrum, contain interpretable information about biological processes. An important problem in sleep research is drawing connections between power spectra of time series signals and clinical characteristics; these connections are key to understanding biological pathways through which sleep affects, and can be treated to improve, health. Such analyses are challenging as they must overcome the complicated structure of a power spectrum from multiple time series as a complex positive-definite matrix-valued function. This article proposes a new approach to such analyses based on a tensor-product spline model of Cholesky components of outcome-dependent power spectra. The approach flexibly models power spectra as nonparametric functions of frequency and outcome while preserving geometric constraints. Formulated in a fully Bayesian framework, a Whittle likelihood based Markov chain Monte Carlo (MCMC) algorithm is developed for automated model fitting and for conducting inference on associations between outcomes and spectral measures. The method is used to analyze data from a study of sleep in older adults and uncovers new insights into how stress and arousal are connected to the amount of time one spends in bed

Bioethics and the Law in Mexico

The results of an empirical study show that,taken as a group, physicians in Mexico do not know what is legal and what is not legal with respect to certain areas of clinical practice.  A number of legal cases are cited showing the ways in which the legal system is ineffective with respect to providing guidance on bioethicalissues.  We conclude that physicians in Mexico do not know what is legal and what is illegal with respect to bioethics because they cannot know (the law is unclear) and because they do not need to know (there is no effective legal precedent or enforcement).  We suggest that the way forward must be through institutional policies establishing standards that depend only upon the traditional contract for medical care

Diagnosis of foregut and tailgut cysts by endosonographically guided fine-needle aspiration

Foregut, hindgut, and tailgut cysts are uncommon developmental anomalies. Clinical and radiological diagnosis can present many challenges, especially in adult patients or when the lesions are in unique locations. Thus, diagnosis has traditionally been provided upon surgical resection. We describe the diagnoses of a gastric foregut cyst and a retrorectal tailgut cyst by endosonographically guided fine-needle aspiration in two adults. The common cytologic features of the specimens are ciliated epithelial cells, proteinaceous material with degenerated debris, histiocytes, and benign appearing epithelium of squamous and/or gastrointestinal type that lack cytologic atypia. The identification of ciliated columnar cells is the key finding. Cytologic diagnosis via endosonographically guided fine-needle aspiration of foregut/hindgut cyst is accurate and less traumatic than surgical biopsies. Diagn. Cytopathol. 2007;35:43–46. © 2006 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/55921/1/20573_ftp.pd

Animal Rights : a Sociological Approach

Building on the political perspective of Sue Donaldson and Will Kymlicka, I propose a sociological approach to animal rights, which takes the various types of human-animal relationships that have developed historically as the basis of current human obligations to members of other species.Siguiendo la perspectiva política de Sue Donaldson y Will Kymlicka, propongo un enfoque sociológico de los derechos de los animales, que toma los diversos tipos de relaciones humano-animales que se han desarrollado históricamente como la base de las obligaciones actuales de los seres humanos hacia los miembros de otras especies

Plausible responses to the threat of rapid sea-level rise for the Thames Estuary

This paper considers the perceptions and responses of selected stakeholders to a scenarion of rapid rise in sea-level due to the collapse of the West Antarctic ice sheet, which could produce a global rise in sea-level of 5 to 6 metres. Through a process of dialogue involving one-to one interviews and a one-day policy exercise, we addressed influences on decision-making when information is uncertain and our ability to plan, prepare for and implement effective ways of coping with this extreme scenario. Through these interactions we hoped to uncover plausible responses to the scenario and identify potential weaknesses in our current flood management approaches to dealing with such an occurrence. By undertaking this exploratory exercise we hoped to find out whether this was a feasible way to deal with such a low probability but high consequence scenario. It was the process of finding a solution that interested us rather than the technical merits of one solution over another. We were not intending to produce definitive set of recommendations on how to respond but to gain insights into the process of making a decision, specifically what influences it and what assumptions are made.Sea level rise, London