Single-voxel proton magnetic resonance imaging (1H-MRS) and proton MR spectroscopic imaging (1H-MRSI) were used to compare brain metabolite levels in semi-acute mild traumatic brain injury (mTBI) patients (n = 10) and matched healthy controls (n = 9). The 1H-MRS voxel was positioned in the splenium, a region known to be susceptible to axonal injury in TBI, and a single 1H-MRSI slice was positioned above the lateral ventricles. To increase sensitivity to the glutamate (Glu) and the combined glutamate-glutamine (Glx) signal, an inter-pulse echo time shown to emphasize the major Glu signals was used along with an analysis method that reduces partial volume errors by using water as a concentration standard. Our preliminary findings indicate significantly lower levels of gray matter Glx and higher levels of white matter creatine-phosphocreatine (Cr) in mTBI subjects relative to healthy controls. Furthermore, Cr levels were predictive of executive function and emotional distress in the combined groups. These results suggest that perturbations in Cr, a critical component of the brain’s energy metabolism, and Glu, the brain’s major neurotransmitter, may occur following mTBI. Moreover, the different pattern of results for gray and white matter suggests tissue-specific metabolic responses to mTBI.

No abstract

[A] compelling case for the institutional analysis of political leadership ... you must buy and read this book.' - R.A.W. Rhodes, Public Administration. '[A] valuable contribution not only to the study of political leadership, but also to the study of comparative politics.' - Valerie Mort, Talking Politics. Concentrating on the period since 1945, Political Leadership in Liberal Democracies examines the resources of and constraints on political leaders in contemporary political systems. The book compares six countries to assess the effectiveness of political leadership and its relationship to the nature of institutional structures and political environments. The author argues that while the leadership environment has become more constraining and difficult in recent years, the potential for effective leadership in liberal democracies has not been extinguished.

A common feature of contemporary political systems is the increasing amount of delegation from governments to non-majoritarian institutions. Governments may decide to delegate authority to such institutions for reasons relating to credible commitments, political uncertainty, and policy complexity. This article focuses on Independent Administrative Authorities (Autorités administratives indépendantes) in France. We demonstrate that these institutions enjoy varying degree of independence. We find that the degree of independence varies as a function of two factors: the need to make a credible commitment in areas subject to market opening and the complexity of policy in particular areas.

Provides an introduction to the concept of semi‐presidentialism and establishes a framework for the study of the politics of semi‐presidential regimes. The first part sketches the evolution of the concept of semi‐presidentialism, considers some of the main criticisms of the concept, proposes a slight reformulation of the standard definition of the term, and identifies a list of semi‐presidential regimes. The second part of the chapter outlines a framework for the comparative study of semi‐presidential regimes, which provides for particular attention to be paid to the constitutional powers of political actors, the circumstances surrounding the creation of the regime, the nature of the parliamentary majority, and the relationship between the president and that majority. In this way, this chapter then provides the basis both for the in‐depth country studies of semi‐presidentialism that follow and for the conclusion, which examines the comparative experience of semi‐presidentialism and addresses the issue of whether countries should adopt a semi‐presidential form of government in preference to either presidential or parliamentary forms of government.