Classifying species as ‘native’ or ‘alien’ carries prescriptive force in the valuation and management of ‘nature’. But the classification itself and its application are contested, raising philosophical and geographical questions about place, space, rights, identity and belonging. This paper discusses leading critiques of the native/alien paradigm, including its conceptual fluidity, dichotomous rigidity and ethical difficulties, as well as the incendiary charge of xenophobia. It argues that valorizing ‘native nature’ as inherently the ‘best nature’ is not only obsolete but impracticable in (...) the Anthropocene, and that the preeminence of biogeographic origins should be replaced with a pragmatic focus on species’ behavior. (shrink)

N- and O-linked glycan structures of cell surface and secreted glycoproteins serve a variety of functions related to cell–cell communication in systems affecting development and disease. The more sophisticated N-glycan biosynthesis pathway of metazoans diverges from that of yeast with the appearance of the medial-Golgi β-N-acetylglucosaminyltransferases (GlcNAc-Ts). Tissue-specific regulation of medial- and trans-Golgi glycosyltransferases contribute structural diversity to glycoproteins in metazoans, and this can affect their molecular properties including localization, half-life, and biological activity. Null mutations in glycosyltransferase genes positioned later (...) in the biosynthetic pathway disrupt expression of smaller subsets of glycan structures and are progressively milder in phenotype. In this review, we examine data on targeted mutations affecting glycosylation in mice and congenital mutations in man, with a view to understanding the molecular functions of glycan structures as modulators of glycoprotein activity. Finally, pathology associated with the expression of GlcNAc-Ts in cancer and diabetes-induced cardiac hypertrophy suggest that inhibitors of these enzymes may have therapeutic value. BioEssays 21:412–421, 1999. © 1999 John Wiley & Sons, Inc. (shrink)

In El Salvador from 1978 to 1988, contraceptive use among married women 15–44 years of age increased from 34% to 47%, and the total fertility rate declined from 6·3 to 4·6 children per woman. Most of this change took place from 1978 to 1985. Sterilization is the most prevalent method used, but nearly one-half of the women who are sterilized did not use any contraception before their operation. Few young couples use reversible methods of contraception to space births or delay (...) the start of childbearing. On average, women wait 8 years after marriage and have nearly three children before they use contraception. (shrink)

A powerful and original statement on the nature of film and the intimate relation of "film imagination" to our lives as human beings in the world.