University of Arizona

About: University of Arizona is a education organization based out in Tucson, Arizona, United States. It is known for research contribution in the topics: Population & Galaxy. The organization has 63805 authors who have published 155998 publications receiving 6854915 citations. The organization is also known as: UA & U of A.

Obstructive Sleep Apnea–Hypopnea and Incident Stroke: the Sleep Heart Health Study

Abstract: Rationale: Although obstructive sleep apnea is associated with physiological perturbations that increase risk of hypertension and are proatherogenic, it is uncertain whether sleep apnea is associated with increased stroke risk in the general population. Objectives: To quantify the incidence of ischemic stroke with sleep apnea in a community-based sample of men and women across a wide range of sleep apnea. Methods: Baseline polysomnography was performed between 1995 and 1998 in a longitudinal cohort study. The primary exposure was the obstructive apnea–hypopnea index (OAHI) and outcome was incident ischemic stroke. Measurements and Main Results: A total of 5,422 participants without a history of stroke at the baseline examination and untreated for sleep apnea were followed for a median of 8.7 years. One hundred ninety-three ischemic strokes were observed. In covariate-adjusted Cox proportional hazard models, a significant positive association between ischemic stroke and OAHI was observed in men (P value for linear trend: P = 0.016). Men in the highest OAHI quartile (>19) had an adjusted hazard ratio of 2.86 (95% confidence interval, 1.1–7.4). In the mild to moderate range (OAHI, 5–25), each one-unit increase in OAHI in men was estimated to increase stroke risk by 6% (95% confidence interval, 2–10%). In women, stroke was not significantly associated with OAHI quartiles, but increased risk was observed at an OAHI greater than 25. Conclusions: The strong adjusted association between ischemic stroke and OAHI in community-dwelling men with mild to moderate sleep apnea suggests that this is an appropriate target for future stroke prevention trials.

Proxy-based reconstructions of hemispheric and global surface temperature variations over the past two millennia

Abstract: Following the suggestions of a recent National Research Council report [NRC (National Research Council) (2006) Surface Temperature Reconstructions for the Last 2,000 Years (Natl Acad Press, Washington, DC).], we reconstruct surface temperature at hemispheric and global scale for much of the last 2,000 years using a greatly expanded set of proxy data for decadal-to-centennial climate changes, recently updated instrumental data, and complementary methods that have been thoroughly tested and validated with model simulation experiments. Our results extend previous conclusions that recent Northern Hemisphere surface temperature increases are likely anomalous in a long-term context. Recent warmth appears anomalous for at least the past 1,300 years whether or not tree-ring data are used. If tree-ring data are used, the conclusion can be extended to at least the past 1,700 years, but with additional strong caveats. The reconstructed amplitude of change over past centuries is greater than hitherto reported, with somewhat greater Medieval warmth in the Northern Hemisphere, albeit still not reaching recent levels.

The Place of Story in the Study of Teaching and Teacher Education

Abstract: ith increasing frequency over the past several years we, as members of a community of investigator-practitioners, have been telling stories about teaching and teacher education rather than simply reporting correlation coefficients or generating lists of findings. This trend has been upsetting to some who mourn the loss of quantitative precision and, they would argue, scientific rigor. For many of us, however, these stories capture, more than scores or mathematical formulae ever can, the richness and indeterminacy of our experiences as teachers and the complexity of our understandings of what teaching is and how others can be prepared to engage in this profession. It is not altogether surprising, then, that this attraction to stories has evolved into an explicit attempt to use the literatures on "story" or "narrative" to define both the method and the object of inquiry in teaching and teacher education. Story has become, in other words, more than simply a rhetorical device for expressing sentiments about teachers or candidates for the teaching profession. It is now, rather, a central focus for conducting research in the field. We are certainly not alone in giving formal attention to story. This term, like others from linguistics and literary theory (e.g., discourse, text, deconstruction), has caught on with considerable enthusiasm throughout the intellectual world and is beginning to appear in widely different contexts. In psychology, for example, Bruner (1985) speaks of a narrative mode of thought, and Sarbin (1986) proposes story as a "root metaphor" for the study of human conduct. Within education, scholars such as Cole and Knowles (1992); Clandinin and Connelly (1992); Elbaz (1991); Grossman (1987); Gudmundsdottir (1991); Hollingsworth (in press); and Richert (1990) have recently made story a central element in their analyses of teachers' knowledge. As Mitchell (1981) noted as early as 1981, "The study of narrative is no longer the province of literary specialists or folklorists ... but has now become a positive source of insight for all branches of human and natural science" (p. ix). Anyone with even a passing familiarity with the literatures on story soon realizes, however, that these are quite turbulent intellectual waters and quickly abandons the expectation of safe passage toward the resolution, once and for all, of the many puzzles and dilemmas we face in advancing our knowledge of teaching. Much needs to be learned about the nature of story and its value to our common enterprise, and about the wide range of purposes, approaches, and claims made by those who have adopted story as a central analytical framework. What does story capture and what does it leave out? How does this notion fit within the emerging sense of the nature of teaching and what it means to educate teachers? These and many other critical questions need to be faced if story is to become more than a loose metaphor for everything from a paradigm or worldview to a technique for bringing home a point in a lecture on a Thursday afternoon. Given both the excitement story has generated and the many issues this movement has brought to the fore, it seems appropriate to provide an analysis of the place of story in the study of teaching and teacher education. My overall purpose here is to begin the process of clarifying the arguments, mapping the intellectual terrain, and casting light on the major issues we need to consider in incorporating story into our research activities. I have no illusions that this discus-

A clinical index to define risk of asthma in young children with recurrent wheezing.

Abstract: Because most cases of asthma begin during the first years of life, identification of young children at high risk of developing the disease is an important public health priority. We used data from the Tucson Children’s Respiratory Study to develop two indices for the prediction of asthma. A stringent index included frequent wheezing during the first 3 yr of life and either one major risk factor (parental history of asthma or eczema) or two of three minor risk factors (eosinophilia, wheezing without colds, and allergic rhinitis). A loose index required any wheezing during the first 3 yr of life plus the same combination of risk factors described previously. Children with a positive loose index were 2.6 to 5.5 times more likely to have active asthma between ages 6 and 13 than children with a negative loose index. Risk of having subsequent asthma increased to 4.3 to 9.8 times when a stringent index was used. We found that 59% of children with a positive loose index and 76% of those with a positive stringent index had active asthma in at least one survey during the school years. Over 95% of children with a negative stringent index never had active asthma between ages 6 and 13. We conclude that the subsequent development of asthma can be predicted with reasonable accuracy using simple, clinically based parameters. Recent longitudinal studies have suggested that, in a large proportion of all cases of asthma, asthmalike symptoms begin during the first years of life (1). Moreover, a long-term follow-up of children with different degrees of asthma severity enrolled in Melbourne, Australia, at the ages of 7 to 10 yr suggests that severity of asthma changes little with time (2). As a consequence, it is the children with the most severe asthma during the school years who become the most severe asthmatics during adult life and up to the age of 35. Children with mild infrequent asthma, on the other hand, have either mild symptoms in early adult life or their symptoms may remit indefinitely (2). Our own studies have also suggested that children who had wheezing lower respiratory tract illnesses during the first 3 yr of life and whose wheezing episodes persisted up to the age of 6 have significantly lower levels of lung function at age 6 compared with children whose wheezing symptoms started after the age of 3 (3). Taken as a whole, these data indicate that early initiation of asthma symptoms is associated with more significant functional deterioration and more persistence of symptoms into adult life (4‐6). The aforementioned considerations have suggested that identification of symptomatic infants and young children who will go on to develop asthma may be very important for the development of a strategy for early intervention aimed at changing the natural course of the disease (4). Unfortunately, wheezy infants who will go on to develop asthma coexist with a larger group of their peers who also wheeze in early life but whose symptoms are transient and usually subside during the preschool or early school years (7). Distinguishing these two asthmalike phenotypes during infancy and early childhood simply on the basis of their clinical presentation is problematic. There are still no reliable genetic markers available and the use of any single biochemical marker is still controversial (1). It is possible, however, that by use of both clinical data and simple, easily obtainable laboratory information, a combination of these parameters may be used to identify children at high risk of developing persistent symptoms in a clinical setting. In the present study, we used the longitudinal data available in the Tucson Children’s Respiratory Study to describe predictive indices for asthma during the school years among children having wheezing episodes during the first 3 yr of life.

2500 Years of European Climate Variability and Human Susceptibility

Abstract: Climate variations influenced the agricultural productivity, health risk, and conflict level of preindustrial societies. Discrimination between environmental and anthropogenic impacts on past civilizations, however, remains difficult because of the paucity of high-resolution paleoclimatic evidence. We present tree ring-based reconstructions of central European summer precipitation and temperature variability over the past 2500 years. Recent warming is unprecedented, but modern hydroclimatic variations may have at times been exceeded in magnitude and duration. Wet and warm summers occurred during periods of Roman and medieval prosperity. Increased climate variability from ~250 to 600 C.E. coincided with the demise of the western Roman Empire and the turmoil of the Migration Period. Such historical data may provide a basis for counteracting the recent political and fiscal reluctance to mitigate projected climate change.