Levator advancement technique for eyelid ptosis

There have been many procedures advocated for the treatment of eyelid ptosis. The technique advocated in this paper consists of careful dissection and identification of anatomic landmarks, including preaponeurotic fat, Whitnall's superior transverse ligament, and the vertically oriented blood supply of the levator muscle. The attachment of the levator muscle into the cephalad portion of the levator muscle into the cephalad portion of the levator aponeurosis can be identified and easily dissected in order to perform the procedure of detachment and advancement to the tarsal plate. This procedure for ptosis has been successful in management in moderate to severe ptosis and in some cases has actually increased the muscle function, thereby enhancing the result. In this technique, the full length of levator muscle remains, so maximum excursion is achieved postoperatively. In addition, this surgical approach may be utilized for levator-lengthening procedures in cases of thyroid exophthalmus or overcorrected ptosis simply by performing the reverse procedure of detachment and insertion of a spacer based on the same ratio. Good results have been achieved in over 20 patients, with the exception of two patients who had absent to poor function and in whom undercorrection was present postoperatively.     

Quantitative ultrastructural changes of the endodermal cells in the early chick embryo analysed by stereological methods

The ultrastructure of endoderm cells of the area pellucida has been analysed in the chick embryo by stereological methods. These cells show a specific subcellular evolution which can be correlated with several aspects of morphogenetic behaviour. The cell form coefficient (CFc) changes notably from stage 5 (0.683) to stage 8 (0.446) accompanying the transformation of this layer into a squamous epithelium. An increase of the nuclear surface density is observed and is discussed in relation to the control of nucleocytoplasmic interchange. The mitochondrial volume and surface densities remain constant (3.12% of cellular volume and 0.727 mitochondria/mu(3) respectively). The endodermal cells possess higher levels of vitelline reserves (lipid bodies, 6.97% and yolk droplets, 8.90%) than other cellular types of the chick embryo. This fact is discussed with respect to the role of the endoderm in the phagocytosis of yolk. The RER length density shows an increase that could be related to some specific changes of the extracellular matrix during this period, but this fact remains to be demonstrated in relation to changes of Golgi membranes.     

Aerodynamics of Ephedra trifurca

Computer simulations are used to predict the behavior of pollen grains with different physical properties within the acceleration field created around the ovules of the gymnosperm Ephedra trifurca. A modelling procedure is given that (1) calculates the number of pollen grains captured by an ovule's pollination-droplet and (2) gives a correlation between pollination efficiency and the physical properties (= mass, size) of different types of pollen. Based on this procedure, the number of Ephedra pollen grains captured by micropyles can be less than the number captured from other species. However, the mass and size of Ephedra pollen grains appear to coincide with those predicted to yield a local maximum of pollination efficiency, i.e. slightly larger or smaller values of either mass or size would decrease the probability of capture. In addition, the properties of Ephedra pollen grains operate synergistically in the aerodynamic environment around ovules and are focused to collide with pollination-droplets. By analogy, the properties of Ephedra pollen coincide with those predicted for a localized adaptive peak. The physical properties of pollen grain types other than E. trifurca that can maximize pollen capture are not generally represented in the aerobiology of Ephedra during the pollination season. Therefore, the phenology of pollen release, community taxonomic-composition, and the physics of particle capture play collectively important roles in the reproductive success of Ephedra trifurca.     

Finger-print patterns in parents of children with Down Syndrome

Finger-prints of the parents of thirty four Down children were compared with thirty four couples with two or more normal children without a family history of genetic problems. The parents with children affected by translocation Down Syndrome and those with mosaicism were excluded. A comparison of the figure distributions in each of the fingers of the two groups shows a different distribution. Parents of children affected by Down Syndrome occupy an intermediate position between the parents of normal children and the subjects affected by Down Syndrome. The total sum of values of A (arch), Lu (ulnar loop), Lt (radial loop) and W in each of the groups were also compared using a contingency table. A significant difference (p<0,05) was found between both groups. The differences are imputed to the variables A and L.     

Diffusion du15N2 dans le sol pendant la mesure de fixation biologique de l'azote

Summary The kinetic of¹⁵N₂ diffusion has been measured in a system similar to that for the estimation of N₂ fixation in plant microorganism associations cultivated in soil. The¹⁵N₂ enrichment of the soil atmosphere reached an homogenous value one hour after injection of¹⁵N₂ and is identical to that obtained by calculation, indicating that no adsorption occurs in the soil particles.

---

Diffusion du¹⁵N₂ dans le sol pendant la mesure de fixation biologique de l'azote

Résumé La cinétique de diffusion du¹⁵N₂ est mesurée sur un système identique à ceux pouvant être utilisés pour la mesure de fixation de l'azote chez les associations plantes-microorganismes cultivées sur sol. L'enrichissement homogène de l'atmosphère du sol est obtenu une heure environ après l'injection de¹⁵N₂ et correspond à l'enrichissement calculé, ce qui indique qu'aucune adsorption n'a lieu dans les particules du sol.

     

Determination of Rubella Hemagglutination-Inhibiting Antibody in Whole Blood

A technique is described for determination of rubella hemagglutination-inhibiting antibody in only 50 to 100 muliters of whole blood.