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E Dyson

Publications and source records attributed to E Dyson.

10 recordsLinked to original sources
PubMed2004

Educational psychology in medical learning: a randomised controlled trial of two aide memoires for the recall of causes of electromechanical dissociation.

OBJECTIVES: Although mnemonics are commonly used in medical education there are few data on their effectiveness. A RCT was undertaken to test the hypothesis that a new aide memoire, "EMD-aide", would be superior to the conventional "4Hs+4Ts" mnemonic in facilitating recall of causes of electromechanical dissociation (EMD) among house officers. METHOD: "EMD-aide", organises causes of EMD by frequency of occurrence and ease of reversibility: four groups organised by shape, colour, position, numbering, clockwise sequence, and use of arrows. Eight hospitals were randomised in a controlled trial and 149 house officers were then recruited by telephone. Baseline ability to recall causes of EMD was recorded at one minute and overall. House officers were then sent a copy of either "4Hs+4Ts" or "EMD-aide" according to randomisation group. Recall ability was retested at one month. RESULTS: 68 of 80 and 51 of 69 house officers completed the study in the "4Hs+4Ts" and "EMD-aide" groups respectively (NS) with similar baseline recall. After intervention median number of recalled causes was greater in the "EMD-aide" group, eight compared with seven at one minute (p = 0.034) and eight compared with seven overall, p = 0.067. Recall of all eight causes was more common in "EMD-aide" group, 54% compared with 35%, p = 0.054, and these house officers spent longer examining their aide memoire, p<0.001. CONCLUSIONS: "EMD-aide" may be superior to "4Hs+4Ts" in facilitating the recall of the causes of electromechanical dissociation. Educational psychology of medical learning and the use of aide memoires in general are worthy of further study.

Abbreviations as Topic↗
PubMed2001

Recruitment of frail older people to research: lessons learnt through experience.

BACKGROUND: With the emphasis on the need for clinical governance and evidence-based practice in the healthcare industry there is increasing pressure on researchers to provide tangible research evidence of the effectiveness of new treatments, interventions and services. Recruiting an adequate size of sample is an important factor in the success or otherwise of a study to answer the research question. Difficulty in the recruitment of older people to research is widely acknowledged. However, much can be achieved to maximize the success of this process. AIMS OF THE PAPER: This paper describes and explores our experience of recruiting frail, older people to research, with particular emphasis on ensuring quality in the process of research related to ethical practice. CONCLUSIONS: Recruitment of frail older people to research can be a complex process in which the awareness and integrity of the researcher is key in upholding the principle of nonexploitation. It is important not to underestimate this difficulty and to ensure that the data collection period is sufficient to recruit adequate numbers. There is a need to continue to develop and refine recruitment skills and strategies to maximize the involvement of frail older people to research while protecting their right to refuse.

Aged↗
PubMed1996

The molecular genetics of retinoic acid receptors: cardiovascular and limb development.

The vitamin A metabolite retinoic acid (RA) is utilized as a signalling molecule in wide variety of developmental processes, defined by defects which occur after nutritional vitamin A deficiency or after exposure to excess vitamin A. We have initiated a genetic analysis of RA function through the establishment of lines of mice which carry germline mutations in the genes which encode retinoid receptors. Defects which result from developmental RA deficiency or excess have been recovered in embryos which are deficient in various combinations of retinoid receptors. In this chapter, our current understanding of the role of RA and retinoid receptors in cardiovascular and limb development are described, as for these our level of understanding is most advanced.

Animals↗
PubMed1995

Atrial-like phenotype is associated with embryonic ventricular failure in retinoid X receptor alpha -/- mice.

We have recently characterized a cardiac model of ventricular chamber defects in retinoid X receptor alpha (RXR alpha) homozygous mutant (-/-) gene-targeted mice. These mice display generalized edema, ventricular chamber hypoplasia, and muscular septal defects, and they die at embryonic day 15. To substantiate our hypothesis that the embryos are dying of cardiac pump failure, we have used digital bright-field and fluorescent video microscopy and in vivo microinjection of fluorescein-labeled albumin to analyze cardiac function. The affected embryos showed depressed ventricular function (average left ventricular area ejection fraction, 14%), ventricular septal defects, and various degrees of atrioventricular block not seen in the RXR alpha wild-type (+/+) and heterozygous (+/-) littermates (average left ventricular area ejection fraction, 50%). The molecular mechanisms involved in these ventricular defects were studied by evaluating expression of cardiac-specific genes known to be developmentally regulated. By in situ hybridization, aberrant, persistent expression of the atrial isoform of myosin light chain 2 was identified in the ventricles. We hypothesize that retinoic acid provides a critical signal mediated through the RXR alpha pathway that is required to allow progression of development of the ventricular region of the heart from its early atrial-like form to the thick-walled adult ventricle. The conduction system disturbances found in the RXR alpha -/- embryos may reflect a requirement of the developing conduction system for the RXR alpha signaling pathway, or it may be secondary to the failure of septal development.

Animals↗
PubMed1994

Chamber specification of atrial myosin light chain-2 expression precedes septation during murine cardiogenesis.

To study the molecular mechanisms that control patterning of the heart tube during early cardiogenesis, we have used the ventricular myosin regulatory light chain (MLC-2v), which is expressed in the ventricular segment of the primitive heart tube, as a genetic marker for ventricular specification in rodents. To assess whether the atrial isoform, MLC-2a, could also serve as a chamber-specific marker, we cloned an atrial MLC-2 cDNA (554 base pairs) which displayed homology to the human MLC-2a cDNA at both the nucleotide (87%) and amino acid (95%) levels. Northern blot, reverse transcriptase-linked polymerase chain reaction, RNase protection, and Western blot analysis revealed atrial restricted expression in the adult mouse heart, very low levels in aorta, and no detectable expression in ventricle, skeletal muscle, uterus, or liver. In situ hybridization studies during mouse embryogenesis revealed cardiac specific expression throughout days 8-16 postcoitum, with atrial restricted expression from day 12 and qualitatively greater atrial expression than ventricular from day 9. Thus, preferential pattern of expression in the atria occurs prior to septation. The MLC-2a gene was differentially regulated when compared with MLC-2v expression during embryonic stem cell cardiogenesis in vitro with MLC-2a transcript levels detectable from day 6 in suspension cultures as compared with day 9 for MLC-2v. The region-specific expression of the MLC-2a and MLC-2v genes in their respective chambers during early cardiogenesis provides genetic markers for chamber specification (atrial and ventricular) in both the in vitro and in vivo context.

Amino Acid Sequence↗
PubMed1994

RXR alpha mutant mice establish a genetic basis for vitamin A signaling in heart morphogenesis.

We have established a targeted loss-of-function mutation in the RXR alpha gene in the mouse germ line that results in embryonic lethality between E13.5 and E16.5 when bred to homozygosity. The major defect responsible for lethality is hypoplastic development of the ventricular chambers of the heart, which is manifest as a grossly thinned ventricular wall with concurrent defects in ventricular septation. This phenotype is identical to a subset of the effects of embryonic vitamin A deficiency and, therefore, establishes RXR alpha as a genetic component of the vitamin A signaling pathway in cardiac morphogenesis. The cardiac outflow tracts and associated vessels, which are populated by derivatives of the neural crest and which are also sensitive to vitamin A deficiency, are normal in homozygous embryos, indicating the genetic independence of ventricular chamber development. Hepatic differentiation was dramatically but transiently retarded yet is histologically and morphologically normal. These results ascribe an essential function for the RXR alpha gene in embryonic development and provide the first evidence of a requirement for RXR in one of its predicted hormone response pathways.

Animals↗
PubMed1986

Defensive aggression toward an experimenter: no differences between males and females following septal, medial accumbens, or medial hypothalamic lesions in rats.

Septal, medial accumbens, medial hypothalamic, or sham lesions were each made in female and male hooded rats. Behavioral testing of defensiveness toward the experimenter was done blind at 6, 9, and 12 days postoperatively by a person who was unaware of the purpose of the experiment. There were no quantitative differences in the defensiveness displayed by male and female rats: both sexes displayed the increase in defensiveness characteristic of each lesion. It is argued that the neural systems modulating defensiveness may be similar in male and female rats and that this is related to evidence from human experiments indicating that comparable levels of defensive aggression are emitted by males and females under controlled experimental conditions.

Aggression↗
PubMedDate not supplied

Looking ahead: implications of the present.

On its seventy-fifth anniversary, HBR asked five of the business world's most insightful thinkers to comment on the challenges taking shape for executives as they move into the next century. In "The Future That Has Already Happened," Peter Drucker examines the effects of the increasing underpopulation of the world's developed countries. With growing imbalances in labor resources worldwide, he writes, executives in the developed countries will need to improve the productivity of knowledge and of knowledge workers to maintain a competitive advantage. Esther Dyson's article "Mirror, Mirror on the Wall" reveals the mind shift executives will need to make in a networked world, where companies will be known for what they do rather than for what they say. Executives will have to respond openly and intelligently to feedback about their organizations. The old language of property and ownership no longer serves executives, writes Charles Handy in "The Citizen Corporation." The corporation should be thought of no longer as property but as a community, where members are regarded as citizens. Technology has given executives more information than today's machines can help them understand, explains Paul Saffo in "Are You Machine Wise?" Machine-wise executives will know when to turn their computers off and take their own counsel, he writes. Peter Senge's article "Communities of Leaders and Learners" urges executives to reject the myth of leaders as isolated heroes and instead to build a community of leaders. Sustained institutional learning, he writes, requires organizations to reintegrate their typically fragmented learning processes.

Administrative Personnel↗