Some new techniques for processing remotely obtained images by self-generated spectral masks

An extension of a new technique that enables parallel, simultaneous processing of remotely obtained images is presented. The technique holds out promise for automatic on-board classification of data. The central feature involves the generation of binary masks, directly from the image, based on object reflectance data, that groups objects into equivalence classes. These masks, called equivalence class masks, can be used in various logical combinations to isolate classes of objects with a priori known reflectance or radiance signatures. Experimental verification of the technique is furnished for simple scenes. A computational scheme, based on a sequence of integrated irradiance measurements on the image, that enables the identification of objects within an equivalence class is suggested.

Saurian malaria: development of sporozoites in two species of phlebotomine sandflies

Sporolzoites of a lizard malaria parasite, Plasmodium mexicanum. developed in two spcies of sandfly-Lutzomyia vexatrix and Lutzomyia stewarti. Salivary g1ands were infected 11 days after the flies took an infective blood meal. This is the first report of a malaria parasite undergoing sporogonic development In an insect other than a mosquito and the first description of lizard malaria sporogenesis.

Pepsin D. A minor component of commercial pepsin preparations

Methods are described for the isolation and purification of pepsin D, an enzyme which accounts for about 10% of the enzymic activity in commercial preparations of pepsin. Pepsin D is similar to pepsin in having a molecular weight of about 35000, the same C-terminal amino acid sequence, and an N-terminal isoleucine residue. It differs in having no phosphate residue. Pepsin D is similar to pepsin in its ability to digest haemoglobin, acetyl-l-phenylalanyl-l-di-iodotyrosine and gelatin but it is twice as active as pepsin in the clotting of milk. It has the same specificity as pepsin in its action on the B-chain of oxidized insulin. It is probable that the pepsin D in commercial preparations of pepsin arises from the activation of gastric pepsinogen D.

Pepsinogen D. A fourth proteolytic zymogen from pig gastric mucosa

Methods are described for the isolation and purification of pepsinogen D, a minor zymogen occurring to the extent of about 5% of the potential proteolytic activity in neutral extracts of the pig gastric mucosa. The physical and chemical properties of this zymogen indicate that it is very similar to, if not identical with, dephosphopepsinogen.