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Biomedical subjects

M Lavelle

Publications and source records attributed to M Lavelle.

At least 19 recordsLinked to original sources
PubMed2001

Orbitally induced oscillations in the East Antarctic ice sheet at the Oligocene/Miocene boundary.

Between 34 and 15 million years (Myr) ago, when planetary temperatures were 3-4 degrees C warmer than at present and atmospheric CO2 concentrations were twice as high as today, the Antarctic ice sheets may have been unstable. Oxygen isotope records from deep-sea sediment cores suggest that during this time fluctuations in global temperatures and high-latitude continental ice volumes were influenced by orbital cycles. But it has hitherto not been possible to calibrate the inferred changes in ice volume with direct evidence for oscillations of the Antarctic ice sheets. Here we present sediment data from shallow marine cores in the western Ross Sea that exhibit well dated cyclic variations, and which link the extent of the East Antarctic ice sheet directly to orbital cycles during the Oligocene/Miocene transition (24.1-23.7 Myr ago). Three rapidly deposited glacimarine sequences are constrained to a period of less than 450 kyr by our age model, suggesting that orbital influences at the frequencies of obliquity (40 kyr) and eccentricity (125 kyr) controlled the oscillations of the ice margin at that time. An erosional hiatus covering 250 kyr provides direct evidence for a major episode of global cooling and ice-sheet expansion about 23.7 Myr ago, which had previously been inferred from oxygen isotope data (Mi1 event).

Journal Article↗
PubMed2001

Effect of different bowel preparations on residual fluid at CT colonography.

The effect of different bowel preparations on residual fluid during computed tomographic (CT) colonography was evaluated. Forty-two patients received either a polyethylene glycol electrolyte solution preparation or a phospho-soda preparation the day prior to CT colonography. The amount of residual fluid was calculated for each patient. On average, a phospho-soda preparation provided significantly less residual fluid than a polyethylene glycol electrolyte solution preparation.

Aged↗
PubMed2001

Investigating physician order entry in the field: lessons learned in a multi-center study.

The progress of studies by this team of researchers concerning computerized physician order entry (POE), beginning with a mail survey and moving to qualitative multi-center studies, is reviewed, with emphases on lessons learned and future directions. While mail surveys were appropriate to answer initial research questions about diffusion of POE in the U.S., multiple qualitative methods became the methods of choice for answering more complex questions. Results of the latter include articulation of multiple perspectives on both positive and negative aspects of POE and a description of what may be important for successful implementation of POE in the future. The present economic environment of hospitals may be inhibiting widespread diffusion of POE, not only because of the direct cost, but also indirectly by affecting relations with practitioners. Analysis of successful past implementations can provide guidance when the time is right.

Attitude to Computers↗
PubMed2000

Comparison of time-efficient CT colonography with two- and three-dimensional colonic evaluation for detecting colorectal polyps.

OBJECTIVE: We compared the findings of time-efficient CT colonography with complete two-dimensional (2D) and three-dimensional (3D) CT colonography and conventional colonoscopy in detecting colorectal polyps. SUBJECTS AND METHODS: Forty-two patients undergoing colonoscopy screening were examined with CT colonography before endoscopy. Data were examined following one of two methods. In method 1, axial 2D data sets were examined in a cine mode. If findings were suggestive of abnormality, focal areas were examined with 3D CT colonography. In method 2, data sets were examined exactly as in method 1, and subsequent to that review, data sets were examined with simultaneous 3D "fly-through" CT colonography (surface-rendered images) and multiplanar reformatted images. The time required to examine CT colonography using each technique was recorded and abnormal findings were documented. Results of methods 1 and 2 were compared with findings on colonoscopy. RESULTS: Colonoscopy detected 16 polyps in 13 patients (polyp size, 2-10 mm). Ten polyps measured 5 mm or less, five measured between 6 and 9 mm, and one measured 10 mm or more. Using method 1, two of 10 polyps measuring less than 5 mm, three of five polyps measuring between 6 and 9 mm, and one polyp measuring 10 mm were detected. We noted no false-positive polyps. Average evaluation time was 16 min. With method 2, the same polyps were seen as with method 1. No additional polyps were detected, and the average evaluation time was 40 min. CONCLUSION: Axial 2D CT colonography can be performed quickly and is comparable with complete 2D and 3D CT colonography in detecting colorectal polyps.

Aged↗
PubMed2000

Recent advances in hepatitis C.

Nearly 2% of Americans are infected with the hepatitis C virus, resulting in 8,000-10,000 deaths each year. The virus can be eradicated with interferon plus ribavirin in about 40% of patients treated for one year. Patients with a history of intravenous drug abuse or transfusion before July 1992 should be screened for hepatitis C, as should members of other high-risk groups. Infected patients should be counseled and if possible offered treatment. This will prevent unnecessary deaths from liver failure and hepatocarcinoma.

Hepatitis C↗
PubMed2000

Multiple perspectives on physician order entry.

OBJECTIVE: Describe the complex interplay of perspectives of physicians, administrators, and information technology staff regarding computerized physician order entry (POE) in hospitals. METHODS: Linstone's Multiple Perspectives Model provided a framework for organizing the results of a qualitative study done at four sites. Data from observation, focus groups, and formal and informal interviews were analyzed by four researchers using a grounded approach. RESULTS: It is not a simple matter of physicians hating POE and others loving it. The issues involved are both complex and emotional. All groups see both positive and negative aspects of POE. CONCLUSION: The Multiple Perspectives Model was useful for organizing a description to aid in understanding all points of view. It is imperative that those implementing POE understand all views and plan implementation strategies accordingly.

Attitude of Health Personnel↗
PubMed1999

Perceptions of house officers who use physician order entry.

OBJECTIVE: Describe the perceptions of housestaff physicians about their experience using computerized physician order entry (POE) in hospitals. METHODS: Qualitative study using data from participant observation, focus groups, and both formal and informal interviews. Data were analyzed by three researchers using a grounded approach to identify patterns and themes in the texts. RESULTS: Six themes were identified, including housestaff education, benefits of POE, problems with POE, feelings about POE, implementation strategies, and the future of POE. CONCLUSION: House officers felt that POE assists patient care but may undermine education. They found that POE works best when tailored to fit local and individual workflow. Implementation strategies should include mechanisms for engaging housestaff in the decision process.

Attitude of Health Personnel↗
PubMed1997

Medicare prospective payment. One agency's response.

A Medicare prospective payment system (PPS) will have major operational implications for home care providers. Recent history has shown that health care providers' behavior is dramatically affected by the incentives inherent in new payment systems. One agency explains how it is changing its behavior in preparation for PPS legislation.

Accounting↗