Biological, Physical, and Chemical Properties of Eastern Equine Encephalitis Virus I. Purification and Physical Properties

A new purification procedure was adopted for Eastern equine encephalitis virus which does not subject the virus to pelleting at any stage. Three- to 4-liter volumes were passed through a diethylaminoethyl cellulose column. The virus-containing fractions were banded on a sucrose cushion and finally concentrated in an isopycnic band in a linear sucrose gradient. This method reduced the volume 1,000-fold with a concomitant increase in viral titer, i.e., better than 90% recovery. Numerous criteria have been used to establish that this viral preparation was essentially free from cellular debris and nonviral material. Physical studies on this purified viral product were initiated. The sedimentation coefficient as determined by band sedimentation was 240S, the buoyant density in sucrose was 1.18 g/cc, and the diameter of the virus was 54 nm. From the diameter and the buoyant density it was possible to calculate the molecular weight of a spherical particle. In this case, the calculated molecular weight for Eastern equine encephalitis virus was 58 x 10(6) daltons.     

GENETIC TIES: ARE THEY MORALLY BINDING?

Does genetic relatedness define who is a mother or father and who incurs obligations towards or entitlements over children? While once the answer to this question may have been obvious, advances in reproductive technologies have complicated our understanding of what makes a parent. In a recent publication Bayne and Kolers argue for a pluralistic account of parenthood on the basis that genetic derivation, gestation, extended custody and sometimes intention to parent are sufficient (but not necessary) grounds for parenthood. ¹ 1 Bayne, T. & Kolers, A. . Toward A Pluralist Account of Parenthood . Bioethics 2003 ; 17 : 221 – 242 .
Bayne and Kolers further suggest that definitions of parenthood are underpinned by the assumption that ‘being causally implicated in the creation of a child is the key basis for being its parent’. ² 2 Ibid. p. 241.
This paper examines the claim that genetic relatedness is sufficient grounds for parenthood based on a causal connection between genetic parents and their offspring. I argue that parental obligations are about moral responsibility and not causal responsibility because we are not morally accountable for every consequence to which we causally contribute. My account includes the conditions generally held to apply to moral responsibility, i.e. freedom and foreseeability. I argue that parental responsibilities are generated whenever the birth of a child is a reasonably foreseeable consequence of voluntary actions. I consider the implications of this account for third parties involved in reproductive technologies. I argue that under some conditions the obligations generated by freely and foreseeably causing a child to exist can be justifiably transferred to others.     

Genetic Analysis of Lysine Auxotrophs of Staphylococcus aureus

The genetics of lysine biosynthesis in Staphylococcus aureus was examined by a transductional analysis of lysine auxotrophs. These mutants had previously been grouped according to their biochemical characteristics. The mutant sites appeared to be closely linked. Complementation was observed between different groups but not between mutant strains belonging to the same group. A strain was detected which seemed to have a mutant control region. Evidence is presented to support the hypothesis that the lysine biosynthetic region functions as an operon.