Effect of carbohydrate on protein solubility

The effect of covalently attached carbohydrate on the solubility of a number of proteins has been examined by the PEG precipitation technique. Both increases and decreases in solubility are observed depending on the state of glycosylation, the type of protein, and temperature. It is concluded from this data and associated apparent thermodynamic parameters that a general role for carbohydrate in the solubilization of proteins is not currently experimentally supportable.     

ORIGINS,EVOLUTION, AND DIVERSIFICATION OF CLEPTOPARASITIC LINEAGES IN LONG‐TONGUED BEES

The evolution of parasitic behavior may catalyze the exploitation of new ecological niches yet also binds the fate of a parasite to that of its host. It is thus not clear whether evolutionary transitions from free‐living organism to parasite lead to increased or decreased rates of diversification. We explore the evolution of brood parasitism in long‐tongued bees and find decreased rates of diversification in eight of 10 brood parasitic clades. We propose a pathway for the evolution of brood parasitic strategy and find that a strategy in which a closed host nest cell is parasitized and the host offspring is killed by the adult parasite represents an obligate first step in the appearance of a brood parasitic lineage; this ultimately evolves into a strategy in which an open host cell is parasitized and the host offspring is killed by a specialized larval instar. The transition to parasitizing open nest cells expanded the range of potential hosts for brood parasitic bees and played a fundamental role in the patterns of diversification seen in brood parasitic clades. We address the prevalence of brood parasitic lineages in certain families of bees and examine the evolution of brood parasitism in other groups of organisms.     

The use of khat

Chewing of khat leaves has been noted to be widespread in Yemen. Immigrants to Israel brought that practice along and have kept it alive ever since their initial settlement over thirty years ago. The small epidemiological study reported here made an inquiry into the extent of khat use in two agricultural villages. It also explored the association of that practice with social and psychiatric variables. Of interest was the finding that — contrary to most addictions — the prevalence rate of psychopathology was not higher among users than among abstainers.