David W. Johnson

Bio: David W. Johnson is an academic researcher from University of Queensland. The author has contributed to research in topics: Peritoneal dialysis & Kidney disease. The author has an hindex of 160, co-authored 2714 publications receiving 140778 citations. Previous affiliations of David W. Johnson include Minnesota Department of Transportation & Open University.

Practice Variation in Acute Bronchiolitis: A Pediatric Emergency Research Networks Study.

Abstract: BACKGROUND AND OBJECTIVES: Studies characterizing hospitalizations in bronchiolitis did not identify patients receiving evidence-based supportive therapies (EBSTs). We aimed to evaluate intersite and internetwork variation in receipt of ≥1 EBSTs during the hospital management of infants diagnosed with bronchiolitis in 38 emergency departments of pediatric emergency research networks in Canada, the United States, Australia, New Zealand, the United Kingdom, Ireland, Spain, and Portugal. We hypothesized that there would be significant variation, adjusted for patient characteristics. METHODS: Retrospective cohort study of previously healthy infants aged RESULTS: Out of 3725 participants, 1466 (39%) were hospitalized, and 1023 out of 1466 participants (69.8%) received EBST. The use of EBST varied by site ( P P = .2). Significant multivariable predictors and their odds ratios (ORs) were as follows: age (0.9), oxygen saturation (1.3), apnea (3.4), dehydration (3.2), nasal flaring and/or grunting (2.4), poor feeding (2.1), chest retractions (1.9), and respiratory rate (1.2). The use of pharmacotherapy and radiography varied by network and site ( P CONCLUSIONS: More than 30% of infants hospitalized with bronchiolitis received no EBST. The hospital site was a source of variation in all study outcomes, and the network also predicted the use of pharmacotherapy and radiography.

Controlled synthesis of new compounds using modulated elemental reactants

Abstract: The design of modulated elemental reactants permits synthetic solid state chemists to control reaction intermediates. This has resulted in the synthesis of new binary and ternary compounds which are thermodynamically unstable relative to disproportionation into known compounds. The ability to control composition as a function of distance in one direction in these reactants permits the synthesis of crystalline superlattices.

Cooperative Learning and Peer Acceptance of Students with Learning Disabilities

Abstract: The effects of cooperative learning on 417 regular-education students' acceptance of 41 of their special-education classmates were examined in an 8-month study. The participants were in Grades 5–8 in 21 classes in 2 U.S. schools. The 3 conditions were cooperative learning and competitive learning, taught by the same teachers, and competitive learning, taught by a random sample of teachers. In October and in May, the regular-education students rated each classmate's desirability as a work partner. The students' peer ratings were generally very stable, for both their regular-education classmates and their special-education classmates. Positive changes in peer ratings for both types of classmates occurred more frequently in the cooperative-learning condition than in the competitive-learning conditions.

An instrumented trial of vibro ground treatment supporting strip foundations in a variable fill

Abstract: Full-scale instrumented load tests have been carried out to study the installation and performance of vibro stone columns supporting a strip foundation in a variable fill and the performance of a similar strip foundation on untreated ground. The results from site investigation and laboratory testing are presented, and the vibro design principles—in particular the use of a modification to a standard formula that reflects the radial densification of soil around the stone column—are outlined. The treated foundation performance is compared with predicted behaviour; calculated settlements are in reasonable agreement with measured values, but stress measurements suggest that current design assumptions significantly overestimate the degree of stress concentration on the stone columns. The degree of radial densification of fill around the stone columns varied according to installation technique and soil type. The implications of the trial observations for existing design methods are considered.

Initial sequencing and analysis of the human genome.

Abstract: The human genome holds an extraordinary trove of information about human development, physiology, medicine and evolution. Here we report the results of an international collaboration to produce and make freely available a draft sequence of the human genome. We also present an initial analysis of the data, describing some of the insights that can be gleaned from the sequence.

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

The social identity theory of intergroup behavior

Abstract: This chapter presents an outline of a theory of intergroup conflict and some preliminary data relating to the theory. Much of the work on the social psychology of intergroup relations has focused on patterns of individual prejudices and discrimination and on the motivational sequences of interpersonal interaction. The intensity of explicit intergroup conflicts of interests is closely related in human cultures to the degree of opprobrium attached to the notion of "renegade" or "traitor." The basic and highly reliable finding is that the trivial, ad hoc intergroup categorization leads to in-group favoritism and discrimination against the out-group. Many orthodox definitions of "social groups" are unduly restrictive when applied to the context of intergroup relations. The equation of social competition and intergroup conflict rests on the assumptions concerning an "ideal type" of social stratification in which the salient dimensions of intergroup differentiation are those involving scarce resources.