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Biomedical subjects

R Campbell

Publications and source records attributed to R Campbell.

At least 235 records · Page 13Linked to original sources
PubMed1976

Constraints on classificatory skills in young children.

On three occasions over a one-year period 23 children aged 3-4 were asked to match target objects with other objects which were similar to the target in shape or in colour but not in both. A sequence of matches to each target was asked for. The structure of these sequences is examined for evidence of classifacatory abilities. Many subjects appear to be attempting (not always successfully) to follow a strategy of 'holding fast' to their original choice of matching criterion (colour or shape) on subsequent trials. The striking differences between performance after a first-trial colour-match and after a first-trial shape-match are described. It is argued that development during this period involves an increasing ability to ignore the more salient attribute (shape) when matching by colour. The general developmental significance is discussed.

Aptitude↗
PubMed1975

Antigen-specific T-cell factor in cell cooperation. Mapping within the I region of the H-2 complex and ability to cooperate across allogeneic barriers.

Further mapping of the mouse T-cell factor specific for poly(Try,Glu)-polyD-LAla--polyLys is reported. It is shown to be a product of the I-A subregion of the H-2 complex by the use of antisera either raised specifically against or made specific, by absorption, for different regions of the H-2 complex. The factor cooperates across allogeneic barriers, e.g., when factor produced by one strian is combined with bone marrow cells of other H-2 incompatible strains.

Animals↗
PubMed1974

Antigen-specific T-cell factor in cell cooperation: physical properties and mapping in the left-hand (K) half of H-2.

Mouse thymus cells, educated to poly(tyrosyl,glutamyl)-polyDLalanyl--polylysyl [(T,G)-A--L], release an antigen-specific factor on brief culture in vitro. The factor cooperates with bone marrow cells in the antibody response to (T,G)-A--L in irradiated recipients. Its mol wt determined from Sephadex G100 chromatography is in the region of 50,000. The factor is removed by specific antigen-coated columns, but not by anti-immunoglobulin (anti-Fab, anti-micro, anti-Fv) adsorbents. The factor is removed by alloantisera directed against the H-2 haplotype of the strain in which it is produced. Moreover, only antisera with specificity for the K side of H-2 were successful in removing the factor activity.

Adsorption↗