PubMed Health⌕ Search

Biomedical subjects

J Macnamara

Publications and source records attributed to J Macnamara.

8 recordsLinked to original sources
PubMed2000

Antibiotics for sore throat: impact of feedback to patients on the probability of bacterial infection.

Antibiotics are overused in the management of sore throat. Using a scoring system with 108 attenders, we provided feedback on the likelihood of bacterial infection and measured the impact on initial patient expectation for antibiotic therapy. Patient attitudes and beliefs regarding antibiotics were also examined. Of sixty two patients whose score suggested viral infection, 18(29%) opted not to take an antibiotic prescription. The 42(67%) who still wanted an antibiotic, despite being told it was "unlikely or highly unlikely" to help, had a higher mean attendance rate for sore throat (1.63 v 0.83 (p = 0.14)) and other illness (6.53 v 4.22 (p = 0.22)), and a higher mean re-attendance rate following the study (1.68 v 0.50 (p = 0.025)). Qualitative analysis suggests that this subgroup may believe in the analgesic properties of antibiotics.

Adolescent↗
PubMed1995

Soft lens movement: effect of blink rate on lens settling.

Little is understood about the mechanism by which soft lenses settle on the eye, although it has been suggested that lens base curve, steepening with in-eye lens dehydration or tear film changes may influence lens movement in the initial period of wear. In this study, we investigated the role of postlens tear fluid expulsion by assessing lens movement in 20 subjects wearing 38% water content hydrogel lenses for 10 min under three different conditions: 10 blinks/min, 30 blinks/min and eye closure. Over the 10 min wearing period, the total decrease in median lens movement for the 10 blinks/min condition was 0.07 mm, which was not a significant change (Friedman ANOVA, p = 0.13), while significant decreases occurred with conditions of 30 blinks/min (0.19 mm, p = 0.004) and eye closure (0.43 mm, p = 0.0001). As expected, lens movement under the three conditions was the same at insertion, but was significantly higher thereafter for the slower blink rate condition compared to the faster blink rate or eye closure conditions (Wilcoxon test, Z = 2.8 and -3.0, p = 0.006 and 0.003, respectively). Based on these findings, we postulate the model that the extent of lens settling and the degree of postinsertion lens movement are determined by the timeaverage pressure for postlens tear film expulsion exerted on the lens by the eyelids.

Adult↗
PubMed1993

Proper names and how they are learned.

Proper names function in our conceptual lives as means for denoting individuals in kinds. Kinds are denoted by common names, more precisely count nouns, and so there are important interrelations between proper names and common nouns. All of this shows up in the way we interpret proper names and employ them in everyday inferences. For example, an airline may count three passengers in relation to a single person Jane, if Jane takes three trips with the airline. Each of the three passengers is Jane, but there is only one Jane. To handle such operations we propose a theory of proper names as part of the theory of kinds. This enables us to specify certain resources (some of them unlearned) that are necessary for the learning of proper names and also a theory of how they are learned. We review the experimental literature on the learning of proper names from the standpoint of the theory. We do not extend the theory to cover recognition or recall.

Cognition↗
PubMed1990

Projective invariance and picture perception.

Four experiments test the assumption that, in the visual perception of pictures, observers have reliable and direct access to the equivalence of shapes in projective geometry. The assumption is that perception of projective equivalence is the basis of shape constancy ('the projective thesis'). Observers matched or reproduced abstract planar shapes under conditions of rotation in the picture plane, and pictured rotation in depth. Departure from projective equivalence was assessed in each study by measuring the planar analogue of cross ratio. Projective equivalence was not found to be perceived uniformly where Euclidean equivalence was not judged uniformly, either in recognition tasks or in production tasks. When the projective thesis is put to a suitably general test, confidence in the thesis is undermined.

Adult↗