Clifford Varley

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This thesis presents methods for the automatic creation of boundary-representation models of polyhedral objects from single line drawings depicting the objects. This topic is important in that automated interpretation of freehand sketches would remove a bottleneck in current engineering design methods. The thesis does not consider conversion of freehand(More)
The maintenance of skin allotolerance induced by perimetamorphic application of MHC-disparate skin to isogeneic Xenopus is investigated. Removal of the perimetamorphically applied first-set graft after 4 weeks did not, in general, completely break allotolerance; however, many second-set semi-allogeneic grafts, applied up to 14 weeks after first-set removal,(More)
Our experiments reveal that application of several minor H antigen-disparate skin grafts to adult Xenopus over an 18-month period can lead to in vitro generation of CML reactivity toward these minor antigens. Furthermore, we demonstrate that, following MHC-disparate skin graft rejection, adult effectors can efficiently kill both adult and larval(More)
Co-rotating interaction regions (CIRs) between fast and slow streams of plasma are a prominent feature of the solar wind. Measurements of interplanetary scintillation (IPS) using the three widely separated antennas of the EISCAT facility have been used to detect the compression regions at the leading edges of interaction regions and to determine the(More)
EISCAT observations of the interplanetary scintillation of a single source were made over an extended period of time, during which the orientation of the baselines between the two observing sites changed signi®cantly. Assuming that maximum correlation between the scintillations observed at the two sites occurs when the projected baseline is parallel to the(More)
Immunohistology, using the T-lineage-specific monoclonal antibody XT-1 and an anti-IgM mAb, illustrates differences in the cellular basis of skin allograft and xenograft destruction displayed by control froglets (X. laevis). Thus T cells predominate within allografts, whereas B-lineage cells accumulate under xenografts (from X. tropicalis). The possibility(More)
Flow cytometric studies employing the monoclonal antibody XT-1 reveal that, in contrast to other strains and species of Xenopus examined, thymocytes and splenocytes from X. tropicalis do not express the T lineage-specific antigen XTLA-1. Thymus dependence of XTLA-1 expression in splenocytes is confirmed in X. laevis by early thymectomy experiments. When X.(More)
In this paper we present a method for detecting rounds and fillets in engineering sketches and drawings, and automatically generating a 3D model of the corresponding object, with rounds and fillets applied. This method is useful both as a component of computer-aided sketching tools and in determining design intent—although rounds and fillets are common in(More)
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