Limitations of the MRL mouse as a model for cardiac regeneration

Objective Myocardial repair following injury in mammals is restricted such that damaged areas are replaced by scar tissue, impairing cardiac function. MRL mice exhibit exceptional regenerative healing in an ear punch wound model. Some myocardial repair with restoration of heart function has also been reported following cryoinjury. Increased cardiomyocyte proliferation and a foetal liver stem cell population were implicated. We investigated molecular mechanisms facilitating myocardial repair in MRL mice to identify potential therapeutic targets in non-regenerative species. Methods Expressions of specific cell-cycle regulators that might account for regeneration (CDKs 1, 2, 4 and 6; cyclins A, E, D1 and B1; p21, p27 and E2F5) were compared by immunoblotting in MRL and control C57BL/6 ventricles during development. Flow cytometry was used to investigate stem cell populations in livers from foetal mice, and infarct sizes were compared in coronary artery-ligated and sham-treated MRL and C57BL/6 adult mice. Key findings No differences in the expressions of cell cycle regulators were observed between the two strains. Expressions of CD34+Sca1+ckit-, CD34+Sca1+ckit+ and CD34+Sca1-ckit+ increased in livers from C57BL/6 vs MRL mice. No differences were observed in infarct sizes, levels of fibrosis, Ki67 staining or cardiac function between MRL and C57BL/6 mice. Conclusions No intrinsic differences were observed in cell cycle control molecules or stem cell populations between MRL and control C57BL mouse hearts. Pathophysiologically relevant ischaemic injury is not repaired more efficiently in MRL myocardium, questioning the use of the MRL mouse as a reliable model for cardiac regeneration in response to pathophysiologically relevant forms of injury.

Vertical toleration as a liberal ideal

This paper argues that the direct, vertical toleration of certain types of citizen by the Rawlsian liberal state is appropriate and required in circumstances in which these types of citizen pose a threat to the stability of the state. By countering the claim that vertical toleration is redundant given a commitment to the Rawlsian version of the liberal democratic ideal, and by articulating a version of that ideal that shows this claim to be false, the paper reaffirms the centrality of vertical toleration in the Rawlsian liberal account of state-citizen relations.

Beyond the "liberal peace"

The article critically reviews the contributions to the understanding of contemporary peacebuilding practices of several recent contributions to the peacebuilding literature, including the 2011 World Development Report. It examines some of the conceptual problems with recent criticisms of the "liberal peace", and proposes that the concept of "liberal peace" should be abandonned as it lacks any analytical purchase.

The civic zeitgeist: nationalism and liberal values in the European radical right

This article examines the relationship between nationalism and liberal values, and more specifically the redefinition of boundaries between national communities and others in the rhetoric of radical right parties in Europe. The aim is to examine the tension between radical right party discourse and the increasing need to shape this discourse in liberal terms. We argue that the radical right parties that successfully operate within the democratic system tend to be those best able to tailor their discourse to the liberal and civic characteristics of national identity so as to present themselves and their ideologies as the true authentic defenders of the nation's unique reputation for democracy, diversity and tolerance. Comparing the success of a number of European radical right parties ranging from the most electorally successful SVP to the more mixed BNP, FN and NPD, we show that the parties that effectively deploy the symbolic resources of national identity through a predominantly voluntaristic prism tend to be the ones that fare better within their respective political systems. In doing so, we challenge the conventional view in the study of nationalism which expects civic values to shield countries from radicalism and extremism.

The Liberal Way of War? French representations of the Allies, 1944-2008

This chapter looks at the ways in which Anglo-American participants in the Liberation of France have been represented in French narratives in the decades since the Second World War, through the developing French historiography of Allied participation in the War, and through the various roles assigned to the Allies in key postwar memorialisation ceremonies in France.

What should we expect of a liberal explanatory theory?

One of the most problematic aspects of the ‘Harvard School’ of liberal international theory is its failure to fulfil its own methodological ideals. Although Harvard School liberals subscribe to a nomothetic model of explanation, in practice they employ their theories as heuristic resources. Given this practice, we should expect them neither to develop candidate causal generalizations nor to be value-neutral: their explanatory insights are underpinned by value-laden choices about which questions to address and what concepts to employ. A key question for liberal theorists, therefore, is how a theory may be simultaneously explanatory and value-oriented. The difficulties inherent in resolving this problem are manifested in Ikenberry’s writing: whilst his work on constitutionalism in international politics partially fulfils the requirements of a more satisfactory liberal explanatory theory, his recent attempts to develop prescriptions for US foreign policy reproduce, in a new form, key failings of Harvard School realism.