As more countries are planning to inaugurate or enlarge student loan schemes, much of the debate is over the question of the optimal form of the repayment obligation: specifically, whether it should be according to a fixed schedule of payments or a percentage or earnings or income. This paper argues that the current fascination with income contingency is frequently based on a set of supposed ad...

We employed intracoronary infusions of calf intestine adenosine deaminase (ADA) to test the hypothesis that adenosine regulates coronary blood flow during myocardial reactive hyperemia (RH). Infusions of 4.5 U ADA/min per kg body weight into the left circumflex coronary artery of 10 open-chest dogs reversibly reduced repayment of flow debt by 30-39% (P less than 0.05) following 5-, 10-, 15-, 20...

OBJECTIVE Previous evidence suggests that episodes of myocardial ischemia of sufficient duration and intensity are required to produce coronary collateral development during repetitive coronary occlusion. This investigation tested the hypothesis that coronary collateral development is also temporal-dependent. METHODS Chronically instrumented dogs (n = 16) were subjected to brief (2 min) left ...

This investigation tested the hypothesis that metabolic syndrome decreases the relative contribution of specific K(+) channels to coronary reactive hyperemia. Ca(2+)-activated (BK(Ca)), voltage-activated (K(V)), and ATP-dependent (K(ATP)) K(+) channels were investigated. Studies were conducted in anesthetized miniature Ossabaw swine fed a normal maintenance diet (11% kcal from fat) or an excess...

We studied the localization of blood flow control in skeletal muscle by shortterm microocclusions (30-60 seconds) of capillaries and arterioles of the pectoralis muscle in anesthetized frogs (Rana pipiens). The muscle was surgically exposed to permit transillumination and measurement of red cell velocity in the microvessels, but innervation and blood supply were kept intact. About one-third of ...

How do borrowers respond to improvements in a lender’s ability to punish defaulters? We implemented a randomized field experiment in Malawi examining the impact of fingerprinting of borrowers, which improves the lender’s ability to withhold future loans from individuals who have previously defaulted while rewarding good borrowers with increased loan sizes. Study participants were smallholder fa...