Some problems with property ascription

We discuss the practice of property ascription in anthropology. While recognizing that it is an inevitable and often useful way to convey the knowledge that anthropologists have acquired through ethnographic fieldwork, we identify three of the most common ways in which ascription can be misleading. First, when a property is ascribed to a collective entity, but it is unevenly distributed among social sub-groupings; second, when an ascribed mental property is alleged to cause an individual's behaviour, but the property proves to be empirically unsupported; third, when a belief is ascribed to an individual, while another belief that effectively contradicts the first one is also entertained by that same individual. We review anthropological and psychological solutions to these problems

Competition between Li+ and Mg2+ for red blood cell membrane phospholipids: A 31P, 7Li, and 6Li nuclear magnetic resonance study

Abstract The mode of action of the lithium ion (Li+) in the treatment of manic depression or bipolar illness is still under investigation, although this inorganic drug has been in clinical use for 50 yr. Several research reports have provided evidence for Li+/Mg2+ competition in biomolecules. We carried out this study to characterize the interactions of Li+ and Mg2+ with red blood cell (RBC) membrane components to see whether Li+/Mg2+ competition occurs. 31P nuclear magnetic resonance chemical shift measurements of the phospholipids extracted from the RBC membranes indicated that the anionic phospholipids, phosphatidylserine and phosphatidylinositol, bind Li+ and Mg2+ most strongly. From 6Li relaxation measurements, the Li+ binding constant to the phospholipid extract was found to be 455M-1. Thus, these studies showed that the phospholipids play a major role in metal ion binding. 7Li spin-lattice relaxation measurements conducted on unsealed and cytoskeleton-depleted RBC membrane in the presence of magnesium indicated that the removal of the cytoskeleton increases lithium binding to the more exposed anionic phospholipids (35724 M-1) when compared to lithium binding in the unsealed RBC membrane (22121 M-1). Therefore, it can be seen that the cytoskeleton does not play a major role in Li+ binding or in Li+/Mg2+ competition