The Right to Survive in North America

Surviving as Indians: The Challenge of Self-Government . Menno Boldt.
"Retained by the People": A History of American Indians and the Bill of Rights . John R. Wunder.     

Strike Fast,Strike Hard: The Red-Throated Caracara Exploits Absconding Behavior of Social Wasps during Nest Predation

Red-throated Caracaras Ibycter americanus (Falconidae) are specialist predators of social wasps in the Neotropics. It had been proposed that these caracaras possess chemical repellents that allow them to take the brood of wasp nests without being attacked by worker wasps. To determine how caracaras exploit nests of social wasps and whether chemical repellents facilitate predation, we: (1) video recorded the birds attacking wasp nests; (2) analyzed surface extracts of the birds'' faces, feet, and feathers for potential chemical repellents; and (3) inflicted mechanical damage on wasp nests to determine the defensive behavior of wasps in response to varying levels of disturbance. During caracara predation events, two species of large-bodied wasps mounted stinging attacks on caracaras, whereas three smaller-bodied wasp species did not. The “hit-and-run” predation tactic of caracaras when they attacked nests of large and aggressive wasps reduced the risk of getting stung. Our data reveal that the predation strategy of caracaras is based on mechanical disturbance of, and damage to, target wasp nests. Caracara attacks and severe experimental disturbance of nests invariably caused wasps to abscond (abandon their nests). Two compounds in caracara foot extracts [sulcatone and iridodial] elicited electrophysiological responses from wasp antennae, and were also present in defensive secretions of sympatric arboreal-nesting Azteca ants. These compounds appear not to be wasp repellents but to be acquired coincidentally by caracaras when they perch on trees inhabited with Azteca ants. We conclude that caracara predation success does not depend on wasp repellents but relies on the absconding response that is typical of swarm-founding polistine wasps. Our study highlights the potential importance of vertebrate predators in the ecology and evolution of social wasps.     

The Continuity of Right and Left Ventricular Myocardial Sinusoidal Spaces and its Relation to Right Ventricular Implants

Evidence is presented which indicates that blood leaving side branches of an internal mammary artery implanted into the anterior wall of the right ventricle flows from the tunnel in which it lies through myocardial sinusoidal spaces of the anterior right ventricular wall across the midline to fill corresponding spaces in the anterior wall of the left ventricle and thence is carried to the left coronary sinus. The myocardial sinusoidal spaces of right and left ventricles have been well outlined, using injections of polyvinyl acetate and the technique of digestion casts. We have been able to show that there is no barrier between the myocardial sinusoids of the right circulation and those related to the anterior descending branch of the left coronary artery. In structure, these myocardial sinusoidal spaces are quite different from the intramyocardial coronary arteriolar zones which, in 93% of human hearts, are separated from one another without collateral communication.The continuity of the right and left ventricular myocardial sinusoids explains why implantation of a right internal mammary artery into the anterior wall of the right ventricle combined with a corresponding left implant, epicardiectomy and free omental graft, has been so effective in our hands in the treatment of far-advanced human coronary artery insufficiency.