Scorpion primers can be used to detect PCR products in homogeneous solution. Their structure promotes a unimolecular probing mechanism. We compare their performance with that of the same probe sequence forced to act in a bimolecular manner. The data suggest that Scorpions indeed probe by a unimolecular mechanism which is faster and more efficient than the bimolecular mechanism. This mechanism is not dependent on enzymatic cleavage of the probe. A direct comparison between Scorpions, TaqMan and Molecular Beacons on a Roche LightCycler indicates that Scorpions perform better, particularly under fast cycling conditions. Development of a cystic fibrosis mutation detection assay shows that Scorpion primers are selective enough to detect single base mutations and give good sensitivity in all cases. Simultaneous detection of both normal and mutant alleles in a single reaction is possible by combining two Scorpions in a multiplex reaction. Such favourable properties of Scorpion primers should make the technology ideal in numerous applications.

In this study we investigated the relationship between food availability, feeding ecology and territoriality in a population of Cactus Finches, Geospiza scandens, on Isla Daphne Major, Galápagos, between 1979 and 1981.We monitored the phenologies of the principal food types on the island and related them to changes in the feeding ecology of G. scandens. Feeding patterns closely tracked the availability of resources, with a similar pattern in each of the three years. Birds relied heavily on Opuntia fruits in the dry season. G. scandens defends year-round territories based on Opuntia. Variation in Opuntia phenologies between individual territories and between years was documented in order to provide a measure of territory quality over the three years. A correlation was demonstrated between the area of cactus within a territory and mating success of the owner. We suggest that territory quality also affects the survival of the owners during periods of food scarcity and that the mating and survival advantage of a high-quality territory occur at different times and to different degrees in different years. Hence the importance of territorial quality can only be judged over a long-term period in these long lived and sedentary birds.

The purpose of this study was to measure the ankle joint contact area under physiological load magnitudes using a stereophotography technique that allows accurate analysis of the entire joint surface without disrupting the joint during loading. Ten cadaveric foot and ankle specimens were loaded to 1000 N in neutral, and 208 dorsiflexion, supination, pronation, and plantarflexion. Photo targets rigidly fixed to each of the bones were imaged in the loaded joint position using a high-resolution stereophotography system. After testing, each ankle was disarticulated and the joint surfaces imaged relative to the photo targets. The photo targets were then used to spatially register the joint surfaces into the loaded joint position; the overlap of the surfaces was used to determine the joint contact area. The mean talo-tibia contact area was greatest in dorsiflexion 7.34 AE 1.69 cm 2 and was significantly larger than in plantar flexion ( p < 0.05), which showed the smallest joint contact area 4.39 AE 1.41 cm 2 . Considering talo-fibula, the maximum contact area was measured in dorsiflexion, 2.02 AE 0.78 cm 2 , and the minimum contact area occurred in pronation, 0.77 AE 0.49 cm 2 , respectively ( p < 0.05). The reported stereophotography technique allows measurement of the joint contact area without disrupting the joint during loading. The contact area is larger than previously reported, as the entire joint surface was analyzed. Joint contact extends over both the talar dome and the talar shoulders where osteochondritis dissecans lesions commonly occur. ß

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