The responsibility to protect and the crisis in Darfur

Governments that have endorsed the 'sovereignty as responsibility' approach have shown little inclination to protect civilians suffering at the hands of their own government in the Sudanese province of Darfur. After providing an overview of Darfur's crisis and international society's feeble response, we explore why the strongest advocates of 'sovereignty as responsibility', the NATO and EU states, failed to seriously contemplate military intervention. We suggest that three main factors help explain the West's unwillingness to intervene in Darfur: increased scepticism about the West's humanitarian interventionism, especially after the invasion of Iraq; Western strategic interests in Sudan; and the relationship between the crisis in Darfur and Sudan's other civil wars. We conclude that the emerging norm of humanitarian intervention remains weak and strongly contested, and that advocates of the 'responsibility to protect' approach have yet to persuade their governments to help save populations in danger.

Anomalous scattering analysis of Agrobacterium radiobacter phosphotriesterase: the prominent role of iron in the heterobinuclear active site

Bacterial phosphotriesterases are binuclear metalloproteins for which the catalytic mechanism has been studied with a variety of techniques, principally using active sites reconstituted in vitro from apoenzymes. Here, atomic absorption spectroscopy and anomalous X-ray scattering have been used to determine the identity of the metals incorporated into the active site in vivo. We have recombinantly expressed the phosphotriesterase from Agrobacterium radiobacter (OpdA) in Escherichia coli grown in medium supplemented with 1 mM CoCl2 and in unsupplemented medium. Anomalous scattering data, collected from a single crystal at the Fe-K, Co-K and Zn-K edges, indicate that iron and cobalt are the primary constituents of the two metal-binding sites in the catalytic centre (alpha and P) in the protein expressed in E. coli grown in supplemented medium. Comparison with OpdA expressed in unsupplemented medium demonstrates that the cobalt present in the supplemented medium replaced zinc at the beta-position of the active site, which results in an increase in the catalytic efficiency of the enzyme. These results suggest an essential role for iron in the catalytic mechanism of bacterial phosphotriesterases, and that these phosphotriesterases are natively heterobinuclear iron-zinc enzymes.

Assessment of statistical change criteria used to define significant change in neuropsychological test performance following cardiac surgery

Objective: This paper compares four techniques used to assess change in neuropsychological test scores before and after coronary artery bypass graft surgery (CABG), and includes a rationale for the classification of a patient as overall impaired. Methods: A total of 55 patients were tested before and after surgery on the MicroCog neuropsychological test battery. A matched control group underwent the same testing regime to generate test–retest reliabilities and practice effects. Two techniques designed to assess statistical change were used: the Reliable Change Index (RCI), modified for practice, and the Standardised Regression-based (SRB) technique. These were compared against two fixed cutoff techniques (standard deviation and 20% change methods). Results: The incidence of decline across test scores varied markedly depending on which technique was used to describe change. The SRB method identified more patients as declined on most measures. In comparison, the two fixed cutoff techniques displayed relatively reduced sensitivity in the detection of change. Conclusions: Overall change in an individual can be described provided the investigators choose a rational cutoff based on likely spread of scores due to chance. A cutoff value of ≥20% of test scores used provided acceptable probability based on the number of tests commonly encountered. Investigators must also choose a test battery that minimises shared variance among test scores.

The UN Security Council and the question of humanitarian intervention in Darfur

This article explores the different moral and legal arguments used by protagonists in the debate about whether or not to conduct a humanitarian intervention in Darfur. The first section briefly outlines four moral and legal positions on whether there is (and should be) a right and/or duty of humanitarian intervention: communitarianism, restrictionist and counter-restrictionist legal positivism and liberal cosmopolitanism. The second section then provides an overview of the Security Council's debate about responding to Darfur's crisis, showing how its policy was influenced by both normative concerns and hard-nosed political calculations. The article concludes by asking what Darfur's case reveals about the legitimacy and likelihood of humanitarian intervention in such catastrophes and the role of the UN Security Council as the primary authorising body for the use of international force. The authors argue that this case demonstrates that for the cosmopolitan/counter-restrictionist case to prevail pivotal states need to put humanitarian emergencies on the global agenda and express a willingness to act without Council authorisation, though the question of how to proceed in cases where the Council is deadlocked remains vexed.