New techniques for the recovery of small amounts of mature enamel proteins

Currently there are no non-destructive techniques to obtain protein from the dental enamel, the most mineralized tissue in mammals and most resistant to diagenesis, which provides a window to the developing period by means of incremental markings containing proteins. To recover protein, dissolution of powdered enamel is required. Here we tested whether samples obtained by micro-etching of the enamel surface were adequate for protein analysis by MALDI-TOF/TOF mass spectrometry and identification in protein databases. The micro-etch techniques were effective in generating adequate samples for mass spectrometry (from 3 to 13.4 μm superficial enamel), being also highly conservative, since they rendered masses of enamel ranging from 0.1 to 0.4 mg. Using these techniques the separation of proteins by SDS-PAGE was not necessary, and the whole procedure was easier. Results showed successful identification of specific enamel proteins after whole crown superficial etching with 11% EDTA in the case of immature porcine samples, and with 10% HCl in the case of mature human enamel. X- and Y-isoforms of amelogenin, ameloblastin, and enamelin peptides were identified. The new techniques described here allowed the successful recovery of enamel proteins, opening new avenues for the use of enamel protein information in fossil/archeological material, where sometimes little protein is left.     

Automated classification of starch granules using supervised pattern recognition of morphological properties

Image analysis techniques have been used to investigate the likelihood of being able to classify and assign a probability regarding the plant origin of individual starch granules in a collection of granules. Quantifiable variables were used to characterize the granules, and the assignments and probabilities were calculated objectively. We consider the classification of images containing granules of a single species and of mixed species and the possibility of assigning a class to granules of unknown species in an image of a slide obtained from the dental calculus of chimpanzees.     

Heretic or Traitor? Spinoza’s Excommunication and the Challenge That Judaism Poses to the Study of Religious Diversity

ABSTRACT

When political theorists talk about “religious diversity,” they usually intend the multiplicity of “religions” in a given society. Yet we now know that the secular, liberal framing of the problematic presupposes a controversial definition of “religion.” My primary goal, in this paper, is to reorient scholarly discussion around what we might call “the critical religion conception of diversity” – not the multiplicity of “religions,” but the myriad ways that the sacred intersects with national and political identity, some of which resist assimilation to the “religious” paradigm. Toward this end, I relate a story about Spinoza’s Hebrew reception in the interwar period. For Zionist intellectuals, Spinoza symbolized the deformations that “religion” imposed on Judaism’s self-understanding and the constraints that it placed on Jewish intellectual horizons. Studying the Zionist critique of “religion” exposes the limitations of received theoretical frameworks, which cannot address the kinds of diversity that were politically consequential for twentieth-century Jews.