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Biomedical subjects

D Billman

Publications and source records attributed to D Billman.

6 recordsLinked to original sources
PubMed2001

Consistent contrast aids concept learning.

We suggest that coherence among concepts and correspondence between concepts and the world are important in concept learning. We identify one aspect of coherence, consistent contrast, and investigate its role in supervised concept learning. Concepts that contrast consistently carry information about the same attributes across the concepts within a contrast set. Concepts that contrast inconsistently predict and are predicted by values of different attributes. Experiment 1 revealed a large advantage for consistent contrast in learning and generalization. Experiment 2 pitted similarity against consistency and still revealed an advantage of consistency. Experiment 2 also broadened the range of tasks considered to include inductions about novel categories and subjects' category descriptions. We discuss relations to theories of concept learning, to attentional mechanism, and to alignability, and we suggest practical implications.

Adult↗
PubMed1994

Exosurf rescue surfactant improves high ventilation-perfusion mismatch in respiratory distress syndrome.

OBJECTIVE: To assess ventilation/perfusion (VA/Q) mismatch of the high type, following rescue surfactant therapy for respiratory distress syndrome. HYPOTHESIS: Surfactant therapy reduces such mismatch. DESIGN: Randomized, double-blind, placebo-controlled study, assessing VA/Q with the arterial-alveolar difference of CO2 tension (P(a-A)CO2). This difference was determined with capnometry and arterial blood gases, using the equation: P(a-A)CO2 equals arterial CO2 minus alveolar CO2 partial pressure. SETTING: A level III nursery. PATIENTS: Ten intubated infants with respiratory distress syndrome. INTERVENTION: Infants were randomized to each receive two doses of surfactant or two doses of air placebo. RESULTS: P(a-A)CO2 improved after surfactant and worsened after placebo (P = 0.0021), comparing slopes of 12-hr regression lines. A similar pattern occurred with oxygenation. These changes in P(a-A)CO2 and in oxygenation were minimally correlated within the surfactant group. CONCLUSION: Exosurf rescue surfactant reduced VA/Q mismatch of the high type, over several hours.

Airway Resistance↗
PubMed1990

Strategy knowledge and strategy change in skilled performance: a study of the game Othello.

Skill and skill development in playing the game Othello were investigated. In particular, we studied the role of strategies and strategy change, rather than focusing on knowledge of particular board patterns. The history of the development of the game suggests a shift from positional to mobility strategies, a change which also is reproduced in the development of individual players. The first two studies used historical analysis of tournament transcripts to study strategy change. The third study investigated one possible basis for the greater accessibility or ease of positional versus mobility strategy, namely differential encoding and memorability of typical board patterns. Study 3 demonstrated that completely naive as well as positional players remember positional games and moves more easily than mobility games and moves. The easier mastery of positional strategy may be caused in part by the greater ease of encoding typical positional patterns. We suggest that strategic change and conceptual reorganization may be particularly important for domains where the naive encoding of events is not the most apt. We also suggest that similarities exist between strategy change in Othello and other domains.

Attention↗
PubMedDate not supplied

Traumatic pseudodiverticulum of the pharynx.

Traumatic pseudodiverticulum of the pharynx is a rare complication of endotracheal intubation. Prompt recognition and management will help in reducing the morbidity. A case of traumatic pseudodiverticulum of the pharynx in a preterm infant and the management with a brief review are reported.

Diverticulum↗
PubMedDate not supplied

Cardiac arrest in an extremely low birth weight infant: complication of percutaneous central venous catheter hyperalimentation.

We report a case of unexpected sudden cardiac arrest in an extremely low birth weight infant on the eighth day after a percutaneous silicone rubber central venous catheter was inserted for parenteral nutrition. The unique pathologic condition of infiltration of the myocardium with probably intralipid and degeneration of myocardial fibers over the right atrium and part of the right ventricle has not been reported in the past. There was no pericardial effusion. A brief review of the complications of central venous catheters is given.

Catheterization, Central Venous↗