A total of 1918 loci, detected by the hybridization of 938 expressed sequence tag unigenes from 26 Triticeae cDNA libraries, were mapped to wheat homoeologous group 4 chromosomes using a set of deletion, ditelosomic, and nulli-tetrasomic lines. The 1918 EST loci were not distributed uniformly among the three group 4 chromosomes; 41, 28, and 31% mapped to chromosomes 4A, 4B, and 4D, respectively. This pattern is in contrast to the cumulative results of EST mapping in all homoeologous groups, as reported (...) elsewhere, that found the highest proportion of loci mapped to the B genome. Sixty-five percent of these 1918 loci mapped to the long arms of homoeologous group 4 chromosomes, while 35% mapped to the short arms. The distal regions of chromosome arms showed higher numbers of loci than the proximal regions, with the exception of 4DL. This study confirmed the complex structure of chromosome 4A that contains two reciprocal translocations and two inversions, previously identified. An additional inversion in the centromeric region of 4A was revealed. A consensus map for homoeologous group 4 was developed from 119 ESTs unique to group 4. Forty-nine percent of these ESTs were found to be homoologous to sequences on rice chromosome 3, 12% had matches with sequences on other rice chromosomes, and 39% had no matches with rice sequences at all. Limited homology was found between wheat ESTs on homoeologous group 4 and the Arabidopsis genome. Forty-two percent of the homoeologous group 4 ESTs could be classified into functional categories on the basis of blastX searches against all protein databases. (shrink)

This paper attempts to answer Joseph B. McAllister’s critique o f the epistemology of F. S. C. Northrop. Toward this end an exposition of the essence of Northrop’s theory of knowledge is presented and a simple comparison with McAllister’s similar effort reveals the latter’s deficiencies. I also reveal how McAllister’s criticism of Northrop’s “supposed” realism depends on equating realism in general with one kind, direct realism. If this is so, then Northrop is neither a skeptic nor a (...) moral or legal relativist. (shrink)

This paper attempts to answer Joseph B. McAllister’s critique o f the epistemology of F. S. C. Northrop. Toward this end an exposition of the essence of Northrop’s theory of knowledge is presented and a simple comparison with McAllister’s similar effort reveals the latter’s deficiencies. I also reveal how McAllister’s criticism of Northrop’s “supposed” realism depends on equating realism in general with one kind, direct realism. If this is so, then Northrop is neither a skeptic nor a (...) moral or legal relativist. (shrink)

In Beauty and Revolution in Science, James McAllister argues that a sophisticated rationalist image of science can accommodate two prominent features of actual scientific practice, namely, appeals to “aesthetic” criteria in theory choice, and the occurrence of scientific “revolutions”. The aesthetic criteria to which scientists appeal are, he maintains, inductively grounded in the empirical record of competing theories, and scientific revolutions involve changes in aestheic criteria bu continuity in empirical criteria of theory choice. I raise difficulties for McAllister's (...) account concerning: (a) the nature and scope of “aesthetic” criteria in science; (b) the rationality of appeals to aestheic criteria in science; (c) the rationality of scientific revolutions. (shrink)