Polarizing activity in the developing limb of the Syrian hamster.

The transplantation of small pieces of tissue from the limb buds of 9 1/2 -10 day hamster embryos to the wing bud of the chick results in the induction of supernumerary wing structures. The anteroposterior polarity of these induced structures is under the control of the transplanted hamster tissue. The developing hamster limb thus has limb polarizing activity similar to that found in avian species and, as in the chick, the activity is found primarily in the posterior region of the limb bud.     

Purification of phosphoinositide-specific phospholipase C from a particulate fraction of bovine brain

The coupling of various agonist receptors to the hydrolysis of phosphoinositides has generated much interest in the nature of the phospholipase C that is activated. Here we report the purification of a bovine brain phospholipase C derived from the particulate fraction. A 1000-fold purification was achieved by a combination of heparin-Sepharose, DEAE-cellulose and gel-permeation chromatography. The purified enzyme appears to be monomeric and under denaturing conditions shows a single staining major polypeptide of molecular mass 154 kDa in SDS gels. The enzyme is specific for phosphoinositides although it shows a marked preference for the polyphosphoinositides. With phosphatidylinositol 4,5-bisphosphate as substrate the enzyme expresses a specific activity of greater than 100 mumol min-1 mg-1. The phospholipase C is activated by Ca2+ (0.1-10 microM). The behaviour of this particulate enzyme is discussed in the context of a agonist-induced phosphatidylinositol hydrolysis.     

It is better to be ignorant of our moral enhancement: A reply to Zambrano

In a recent issue of Bioethics, I argued that compulsory moral bioenhancement should be administered covertly. Alexander Zambrano has criticized this argument on two fronts. First, contrary to my claim, Zambrano claims that the prevention of ultimate harm by covert moral bioenhancement fails to meet conditions for permissible liberty-restricting public health interventions. Second, contrary to my claim, Zambrano claims that covert moral bioenhancement undermines autonomy to a greater degree than does overt moral bioenhancement. In this paper, I rebut both of these arguments, then finish by noting important avenues of research that Zambrano’s arguments motivate.     

Morphogenia: a new genus of the Neotropical tribe Jubini (Coleoptera,Staphylinidae, Pselaphinae) from the Brazilian Amazon

A new genus and species of the large Neotropical pselaphine tribe Jubini is described from Manaus, Brazil, based on material preserved in the Natural History Museum, London. Morphogenia struhli gen. et sp. n. represents the possible sister taxon of the abundant and speciose genus Barrojuba Park, sharing with it the putatively derived condition of anterolaterally shifted vertexal foveae, producing a smoothly convex vertex devoid of fovea or sulci. However, unlike Barrojuba, Morphogenia retains a plesiomorphic antebasal sulcus on the pronotum in both sexes, and additionally lacks elaborate abdominal fovea-like pockets and teeth on the lateral margins of the pronotum that are typical of Barrojuba. The genus is also unusual among jubine genera in lacking the characteristic V- or Y-shaped gular carina. In contrast to the commonly-collected Barrojuba, specimens of Morphogenia are absent in extensive jubine collections housed in museums in the United States, indicating that the new taxon may be relatively scarce or localised.