Thallium Sulphate is one of the most lethal chemicals known. Its commercial use has been banned in the West and in many Third World countries. However, it recently came to light that the Guyana Sugar Corporation was importing large amounts of the substance and that this has led to acute and chronic poisoning of many Guyanese. This paper examines this case and discusses its ethical implications.

Properties A stone, a bag of sugar and a guinea pig all weigh one kilogram. A lily, a cloud and a sample of copper sulphate are white. A statue, a dance and a mathematical equation are beautiful. The fact that distinct particular things can be the same as each other and yet different has been … Continue reading Properties →.

Although it could avoid some harmful effects of climate change, sulphate aerosol geoengineering (SAG), or injecting sulphate aerosols into the stratosphere in order to reflect incoming solar radiation, threatens substantial harm to humans and non-humans. I argue that SAG is prima facie ethically problematic from anthropocentric, animal liberationist, and biocentric perspectives. This might be taken to suggest that ethical evaluations of SAG can rely on Bryan Norton's convergence hypothesis, which predicts that anthropocentrists and non-anthropocentrists will agree to implement (...) the same or similar environmental policies. However, there are potential scenarios in which anthropocentrists and non-anthropocentrists would seem to diverge on whether a particular SAG policy ought to be implemented. This suggests that the convergence hypothesis should not be relied on in ethical evaluation of SAG. Instead, ethicists should consider the merits and deficiencies of both non-anthropocentric perspectives and the ethical evaluations of SAG such perspectives afford. (shrink)

While climate change mitigation remains indispensable, together with adaptation to such climate change as cannot be prevented, current slowness of progress towards attaining an international agreement on these matters has fostered suggestions about climate engineering, originally proposed as supplementary to adaptation and mitigation. These suggestions take the forms of Solar Radiation Management and Carbon Dioxide Removal. This paper discusses the ethics of researching and of deploying them. Solar Radiation Management ranges from harmless but inadequate measures such as making roofs reflect (...) sunlight to ambitious ones such as projecting sulphate aerosols into the stratosphere to reduce incoming radiation. Some favor this measure as a quick and inexpensive replacement for mitigation; but its possible side-effects and lack of an exit-strategy mean that its deployment would be misguided, and that researching it might undermine determination to reach a mitigation agreement. Some forms of Carbon Dioxide Removal face similar objections, but others, like afforestation and Carbon Capture and Storage, comprise acceptable enhancements of current technology. Even if they do not buy time, these measures could beneficially supplement a global Climate Change agreement. (shrink)

Although interactions of proteins with glycosaminoglycans (GAGs), such as heparin and heparan sulphate, are of great biological importance, structural requirements for protein‐GAG binding have not been well‐characterised. Ionic interactions are important in promoting protein‐GAG binding. Polyelectrolyte theory suggests that much of the free energy of binding comes from entropically favourable release of cations from GAG chains. Despite their identical charges, arginine residues bind more tightly to GAGs than lysine residues. The spacing of these residues may determine protein‐GAG affinity and (...) specificity. Consensus sequences such as XBBBXXBX, XBBXBX and a critical 20 Å spacing of basic residues are found in some protein sites that bind GAG. A new consensus sequence TXXBXXTBXXXTBB is described, where turns bring basic interacting amino acid residues into proximity. Clearly, protein‐GAG interactions play a prominent role in cell‐cell interaction and cell growth. Pathogens including virus particles might target GAG‐binding sites in envelope proteins leading to infection. BioEssays 20:156–167, 1998. © 1998 John Wiley & Sons, Inc. (shrink)

Fibroblast growth factor receptors (FGFRs) have been implicated in many developmental and regenerative events, including axial organisation, mesodermal patterning, keratinocyte organisation and brain development. The consensus view that this reflects a role for one or other of the nine known members of the fibroblast growth factor family in these processes has recently been challenged by the suggestion that FGFRs might be directly activated by a much wider range of ligands, including heparan sulphate proteoglycans and neural cell adhesion molecules. In (...) addition, two novel soluble ligands for FGFRs have been identified using yeast two‐hybrid technology. Overall, the new findings suggest that in terms of ligand binding the FGFRs might be an even more promiscuous family of receptor tyrosine kinases than was already appreciated. (shrink)