Expertise and Bias in Political Communication Networks

Citizens minimize information costs by obtaining political guidance from others who have already assumed the costs of acquiring and processing political information. A problem occurs because ideal informants, typically characterized by the joint presence of political expertise and shared viewpoints, are frequently unavailable or rare within the groups where individuals are located. Hence, individuals must often look beyond their own group boundaries to find such informants. The problem is that obtaining information from individuals located beyond their own groups produces additional costs. Moreover, the availability of ideal informants varies across groups and settings, with the potential to produce (1) context‐dependent patterns of informant centrality, which in turn generate (2) varying levels of polarization among groups and (3) biases in favor of some groups at the expense of others. The article's analysis is based on a series of small‐group experiments, with aggregate implications addressed using a simple agent‐based model.     

Shot Through the Heart—Firepower and Potential Lethality of Air Weapons

Although certain air weapons attain muzzle velocities comparable to some firearms, their successful use for committing suicide is rarely seen. Herein, we report a case of a young female died shortly after urgent admission to the hospital with penetrating gunshot wound to the chest. The autopsy revealed perforation of the pericardium and two perforative defects to the right heart ventricle. Injury was inflicted by a 0.177 caliber pellet, fired from an air rifle found near her body. Investigation ruled the death as suicide. The used air rifle fired the pellet with the energy density of 1.9 J/mm², substantially above the threshold for inflicting injury. The pellet penetrated through two layers of cotton fabric and several layers of tissue to inflict fatal injury to the heart. In addition, we provide an insight into the wounding potential of air weapons, which illustrates the need for greater caution in handling those devices.