Maylor Karhang Leung

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A novel ellipse detector based upon edge following is proposed in this paper. The detector models edge connectivity by line segments and exploits these line segments to construct a set of elliptical-arcs. Disconnected elliptical-arcs which describe the same ellipse are identified and grouped together by incrementally finding optimal pairings of(More)
Various reports have shown that invertebrate hemocytes are responsive to mammalian neuropeptides and cytokines. In the present study, we demonstrate that corticotropin-releasing factor (CRF) and adrenocorticotropin (ACTH) fragments (1-24), (1-4), (4-9), (1-13), (1-17), and (11-24) significantly stimulate molluscan hemocyte migration, and the whole sequence(More)
This study deals with a novel role of morphine in the modulation of cellular responsiveness to immunostimulatory substances that, at first glance, appears to be in contrast to the well documented immunoinhibitory short-term effects of opiate alkaloids on cells simultaneously exposed to stimulatory molecules. Vertebrate and invertebrate immunocytes(More)
D'-Ala-2 met-5-enkephalinamide application to the cerebral ganglia of Leucophaea maderae results in a decrease in locomotor activity. The opiate antagonist, naloxone, can block this effect as well as the depressant effect of morphine on locomotor activity. D-Ala-2,leu-5-enkephalinamide and dynorphin enhance locomotor activity following their topical(More)
An extract of pedal ganglia of Mytilus edulis was fractioned by high-pressure liquid chromatography by use of a reverse-phase column. Peak fractions with the same retention time as Met-enkephalin-Arg6-Phe7 were subjected to binding assays in invertebrate neural tissue. The results showed that these fractions have the same binding activities as authentic(More)
1. Computerized analysis of the crabs locomotor behavior revealed an initial increase in activity followed by a gradual decrease over a 12 min observation period. 2. Dopamine, in a dose-dependent manner, inhibits locomotor activity. The effect can be antagonized with the dopamine antagonist, haloperidol. This suggests that dopaminergic influences are(More)
We present a novel contour-based approach that recognizes object classes in real-world scenes using simple and generic shape primitives of line segments and ellipses. Compared to commonly used contour fragment features, these primitives support more efficient representation since their storage requirements are independent of object size. Additionally, these(More)
The eyestalk of the land crab, Gecarcinus lateralis, is rich in Met-enkephalin-like materials. Leu-enkephalin, if present, is at a level which is below the sensitivity of our assay. The brain (cerebral ganglion) of this organism contains both Met- and Leu-enkephalin-like materials. Material which was reactive with our Met-enkephalin antibody was also(More)
1. This review article provides information on the evolutionary history of neuroendocrine and related regulatory mechanisms. It focuses on the presence, diverse roles, and modes of operation of one class of neuropeptides, the endogenous opioids, in insects. 2. Opioid peptides, closely resembling those of vertebrates, have been identified in the brain and(More)