Civilianizing Civil Conflict: Civilian Defense Militias and the Logic of Violence in Intra-State Conflict

This article examines how civilian defense militias shape violence during civil war. We define civilian defense forces as a sedentary and defensive form of pro-government militia that incumbents often use to harness the participation of civilians during a counterinsurgency campaign. We argue that civilian defense forces reduce the problem of insurgent identification. This leads to a reduction in state violence against civilians. However, we also claim that these actors undermine civilian support for insurgents, which leads to an increase in rebel violence against civilians and overall intensification of conflict. A statistical analysis of government and rebel violence against civilians from 1981 to 2005, and a qualitative assessment of a civilian defense force operating in Iraq from 2005 to 2009, offer strong support for our theoretical claims. These findings provide further insight into pro-government militias and their effects on violence. They also have wider ethical implications for the use of civilian collaborators during civil war.

Mechanical stretch up-regulates the B-type natriuretic peptide system in human cardiac fibroblasts:a possible defense against transforming growth factor-β mediated fibrosis

BACKGROUND: Mechanical overload of the heart is associated with excessive deposition of extracellular matrix proteins and the development of cardiac fibrosis. This can result in reduced ventricular compliance, diastolic dysfunction, and heart failure. Extracellular matrix synthesis is regulated primarily by cardiac fibroblasts, more specifically, the active myofibroblast. The influence of mechanical stretch on human cardiac fibroblasts' response to pro-fibrotic stimuli, such as transforming growth factor beta (TGFβ), is unknown as is the impact of stretch on B-type natriuretic peptide (BNP) and natriuretic peptide receptor A (NPRA) expression. BNP, acting via NPRA, has been shown to play a role in modulation of cardiac fibrosis.

METHODS AND RESULTS: The effect of cyclical mechanical stretch on TGFβ induction of myofibroblast differentiation in primary human cardiac fibroblasts and whether differences in response to stretch were associated with changes in the natriuretic peptide system were investigated. Cyclical mechanical stretch attenuated the effectiveness of TGFβ in inducing myofibroblast differentiation. This finding was associated with a novel observation that mechanical stretch can increase BNP and NPRA expression in human cardiac fibroblasts, which could have important implications in modulating myocardial fibrosis. Exogenous BNP treatment further reduced the potency of TGFβ on mechanically stretched fibroblasts.

CONCLUSION: We postulate that stretch induced up-regulation of the natriuretic peptide system may contribute to the observed reduction in myofibroblast differentiation.