The Call for a New Definition of Biosignature.

The term has become increasingly prevalent in astrobiology literature as our ability to search for life advances. Although this term has been useful to the community, its definition is not settled. Existing definitions conflict sharply over the balance of evidence needed to establish a biosignature, which leads to misunderstanding and confusion about what is being claimed when biosignatures are purportedly detected.

Confidence of Life Detection: The Problem of Unconceived Alternatives.

Potential biosignatures that offer the promise of extraterrestrial life (past or present) are to be expected in the coming years and decades, whether from within our own solar system, from an exoplanet atmosphere, or otherwise. With each such potential biosignature, the degree of our uncertainty will be the first question asked. Have we really identified extraterrestrial life? How sure are we? This paper considers the problem of unconceived alternative explanations.

Disarming the Ultimate Historical Challenge to Scientific Realism.

Probably the most dramatic historical challenge to scientific realism concerns Arnold Sommerfeld's ([1916]) derivation of the fine structure energy levels of hydrogen. Not only were his predictions good, he derived exactly the same formula that would later drop out of Dirac's 1928 treatment (something not possible using 1925 Schrödinger-Heisenberg quantum mechanics). And yet the most central elements of Sommerfeld's theory were not even approximately true: his derivation leans heavily on a classical approach to elliptical orbits, including the necessary adjustments to these orbits demanded by relativity.

Conducting qualitative research with palliative care patients: applying Hammick's research ethics wheel.

This paper discusses the particular ethical issues that are present when attempting to undertake research involving patients accessing palliative care for cancer. It focuses on the use of Hammick's research ethics wheel (REW) in relation to a research study undertaken by the authors. Applying the REW enabled the authors to identify and incorporate the ethical issues and dilemmas inherent within such a study at a practical level.

Childcare nursing is growing up.

Theresa Atherton warned that Project 2000-trained childcare branch nurses could find themselves unsuited to many NHS managers' requirements (Childcare nursing: the faltering first steps, Viewpoint February 10).