The Tennison Lip repair revisited

Tennison presented his method for the repair of the single cleft. He was the first to recognize and to preserve the cupid's bow by lowering the peak in the margin of the cleft. He incised the medial side of the cleft and filled the space with a triangular flap from the lateral side. We have modified the Tennison repair based on the vertical height of the normal side, as did Randall and Hagerty. We make the lip 1 mm shorter in the vertical height than the normal side because some of our repairs were too long. Other modifications include a 1-mm offset at the vermilion, and in certain lips that are too long in the newborn, a triangle is excised beneath the alar base to shorten the vertical height. The details for planning the incisions and accomplishing the surgery are given. Certain patients required a V-to-Y procedure to augment a vermilion deficiency, but none of these patients required a secondary procedure. This emphasizes the need for careful planning to get it right at the primary repair. The operation is indicated for the incomplete cleft to the very wide cleft, and in no patient was a lip adhesion required. We no longer operate on the nose at the primary repair.     

Acid-labile amino acid precursors in the Murchison meteorite. 1: Chromatographic fractionation.

The amino acid content of a hot water extract of the Murchison meteorite can be increased by over 100 per cent by subjecting the extract to acid hydrolysis. The acid-labile compounds in the extract that account for this increase were fractionated by column chromatography on a cation exchange resin. Seventy mole per cent behaved as neutral or acidic compounds and were eluted from the column with an initial water wash. The remaining 30 mole per cent (basic precursors) were retained on the column and were eluted with the free amino acids by aqueous NH4OH. The acid-labile amino acid precursors in the water eluate could be retained and further fractionated on an anion exchange column, indicating that they are acidic compounds.     

Sex ratios, local fitness enhancement and eusociality in the allodapine bee Exoneura richardsoni

Previous studies of a facultatively eusocial allodapine bee, Exoneura richardsoni Rayment, indicated that high levels of cooperative nesting among close relatives seem to be maintained by benefits that lead to increases in per capita brood production. These traits could lead to local fitness enhancement, which in turn could select for female-biased sex ratios. We show here that sex investment ratios in this species are female-biased in small colony sizes, becoming progressively male-biased in larger colonies, consistent with expectations for local fitness enhancement, but not explainable by alternative models. Our results support previous suggestions that local fitness enhancement can lead to sex ratio bias in primitively social Hymenoptera, but differ from previous studies by suggesting that patterns of bias could lower selective thresholds for sib-directed altruism in small colonies, but have an opposing effect in large colonies.     

Coupling polylysine to glass beads for plasma membrane isolation

Solid glass beads for use in isolating cell membranes were coated with a stable, covalently attached layer of polylysine. The optimal conditions for coating the bead surface were established and the beads were tested by measuring the attachment of human erythrocyte plasma membranes. When compared to other beads, such as those with absorbed polylysine or protamine, none retained red-cell membranes as well as glass beads with covalently linked polylysine.     

Cooperative problem solving in a cooperatively breeding primate (Saguinus oedipus)

We investigated cooperative problem solving in unrelated pairs of the cooperatively breeding cottontop tamarin, Saguinus oedipus, to assess the cognitive basis of cooperative behaviour in this species and to compare abilities with other apes and monkeys. A transparent apparatus was used that required extension of two handles at opposite ends of the apparatus for access to rewards. Resistance was applied to both handles so that two tamarins had to act simultaneously in order to receive rewards. In contrast to several previous studies of cooperation, both tamarins received rewards as a result of simultaneous pulling. The results from two experiments indicated that the cottontop tamarins (1) had a much higher success rate and efficiency of pulling than many of the other species previously studied, (2) adjusted pulling behaviour to the presence or absence of a partner, and (3) spontaneously developed sustained pulling techniques to solve the task. These findings suggest that cottontop tamarins understand the role of the partner in this cooperative task, a cognitive ability widely ascribed only to great apes. The cooperative social system of tamarins, the intuitive design of the apparatus, and the provision of rewards to both participants may explain the performance of the tamarins.