The objectives of this study were to develop a high-density chromosome bin map of homoeologous group 7 in hexaploid wheat, to identify gene distribution in these chromosomes, and to perform comparative studies of wheat with rice and barley. We mapped 2148 loci from 919 EST clones onto group 7 chromosomes of wheat. In the majority of cases the numbers of loci were significantly lower in the centromeric regions and tended to increase in the distal regions. The level of duplicated loci (...) in this group was 24% with most of these loci being localized toward the distal regions. One hundred nineteen EST probes that hybridized to three fragments and mapped to the three group 7 chromosomes were designated landmark probes and were used to construct a consensus homoeologous group 7 map. An additional 49 probes that mapped to 7AS, 7DS, and the ancestral translocated segment involving 7BS also were designated landmarks. Landmark probe orders and comparative maps of wheat, rice, and barley were produced on the basis of corresponding rice BAC/PAC and genetic markers that mapped on chromosomes 6 and 8 of rice. Identification of landmark ESTs and development of consensus maps may provide a framework of conserved coding regions predating the evolution of wheat genomes. (shrink)

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)

The complex hexaploid wheat genome offers many challenges for genomics research. Expressed sequence tags facilitate the analysis of gene-coding regions and provide a rich source of molecular markers for mapping and comparison with model organisms. The objectives of this study were to construct a high-density EST chromosome bin map of wheat homoeologous group 2 chromosomes to determine the distribution of ESTs, construct a consensus map of group 2 ESTs, investigate synteny, examine patterns of duplication, and assess the colinearity with rice (...) of ESTs assigned to the group 2 consensus bin map. A total of 2600 loci generated from 1110 ESTs were mapped to group 2 chromosomes by Southern hybridization onto wheat aneuploid chromosome and deletion stocks. A consensus map was constructed of 552 ESTs mapping to more than one group 2 chromosome. Regions of high gene density in distal bins and low gene density in proximal bins were found. Two interstitial gene-rich islands flanked by relatively gene-poor regions on both the short and long arms and having good synteny with rice were discovered. The map locations of two ESTs indicated the possible presence of a small pericentric inversion on chromosome 2B. Wheat chromosome group 2 was shown to share syntenous blocks with rice chromosomes 4 and 7. (shrink)

The third volume of Professor Guthrie's great history of Greek thought, entitled The Fifth-Century Enlightenment, deals in two parts with the Sophists and Socrates, the key figures in the dramatic and fundamental shift of philosophical interest from the physical universe to man. Each of these parts is now available as a paperback with the text, bibliography and indexes amended where necessary so that each part is self-contained. The Sophists assesses the contribution of individuals like Protagoras, Gorgias and Hippias to the (...) extraordinary intellectual and moral fermant in fifth-century Athens. They questioned the bases of morality, religion and organized society itself and the nature of knowledge and language; they initiated a whole series of important and continuing debates, and they provoked Socrates and Plato to a major restatement and defence of traditional values. (shrink)

The third volume of Professor Guthrie's great history of Greek thought, entitled The Fifth-Century Enlightenment, deals in two parts with the Sophists and Socrates, the key figures in the dramatic and fundamental shift of philosophical interest from the physical universe to man. Each of the two parts is available as a paperback with the text, bibliography and indexes amended where necessary so that each part is self-contained. Socrates dominated the controversies of this period, as he has dominated the subsequent history (...) of western philosophy. He was the first to identify and grapple with some of the most intractable and persistent logical and philosophical problems; but he was also and has remained a highly controversial figure because of his extraordinary personal qualities and his remarkable career. Professor Guthrie offers a balanced and comprehensive picture of the man, his life, and his thought. (shrink)

"Sets a standard for rigor, parsimony and theoretical elegance in cognitive modeling....Offers a coherent and predictive system for tackling both specific and general issues." --Science.

The work of Professor Jaeger on the Aristotelian metaphysics, and its modification by the late Hans von Arnim, have raised many new points of the greatest interest, and may, I hope, be considered as having opened up a large and fascinating new field for discussion rather than as having closed the matter. It is a subject which must be considered as a whole. There would be little profit in writing short notes on isolated points in the arguments of the two (...) scholars. Anyone who, possessed of some previous acquaintance with the Aristotelian corpus, reads their work is inevitably stimulated to return to Aristotle with his mind full of fresh ideas. If after a re-examination of the texts he feels he has a different story to tell, he must tell it for himself. That is my excuse for an account which must include much which was always known and much which has arisen out of the work of Jaeger and von Arnim. My conclusions are not the same as theirs, and the argument must stand or fall as a consistent whole. (shrink)

The symbol grounding problem is concerned with the question of how the knowledge used in AI programs, expressed as tokens in one form or another or simply symbols, could be grounded to the outside world. By grounding the symbols, it is meant that the system will know the actual objects, events, or states of affairs in the world to which each symbol refers and thus be worldly-wise. Solving this problem, it was hoped, would enable the program to understand its own (...) action and hence be truly intelligent ). The problem becomes more acute after a challenge posed by Searle in his now famous Chinese Room Gedanken experiment. Searle argued that no AI programs can be said to understand or have other cognitive states, if all they do is formal symbol manipulation. (shrink)

Austin argued that ‘if’ has sometimes a non-conditional function, his reason being that some types of if-statement are deviant by two criteria which establish a norm. Following Pears more or less closely, I shall refer to applications of these criteria as the contrapositive and nondetachment tests, and to any if-statement which fails at least one test as a pseudoconditional, or more briefly as a pseudo. Thus, to turn directly to the narrower subject of this paper- the singularity Austin exposed in (...) a thesis of Moore's - ‘He can, if he chooses’ fails either test. It does not entail ‘lf he cannot, he does not choose to’. Nor does it entail ‘He can’. Hence, it is doubly pseudo - and the same applies after systematic variation in grammatical person, tense and mood. (shrink)