Review of: It Just Ain\u27t Fair: The Ethics of Health Care for African Americans (Annette Dula & Sara Goering eds.)

Review of: It Just Ain\u27t Fair: The Ethics of Health Care for African Americans (Annette Dula & Sara Goering eds., Praeger 1994) About the editors and contributors, acknowledgements, bibliography, foreword by Mark Siegler, index, notes. L.C. 93-43780, ISBN 0-275-94494-8. [ 336 pp. Paper $19.95. P.O. Box 5007, Westport CT 06881-5007.

Land Reform and Landholdings in Brazil

land reform, land distribution, wealth distribution

Nietzsche for physicists

One of the most important philosophers in history, the German Friedrich Nietzsche, is almost ignored by physicists. This author who declared the death of God in the 19th century was a science enthusiast, especially in the second period of his work. With the aid of the physical concept of force, Nietzsche created his concept of will to power. After thinking about energy conservation, the German philosopher had some inspiration for creating his concept of eternal recurrence. In this article, some influences of physics on Nietzsche are pointed out, and the topicality of his epistemological position$-$the perspectivism$-$is discussed. Considering the concept of will to power, I propose that the perspectivism leads to an interpretation where physics and science in general are viewed as a game.Comment: 14 pages. Version 3 with improvements, corrections. Accepted in Philosophia Scientia

Constraining the tidal charge of brane black holes using their shadows

A constraint on the tidal charge generated within a brane world is shown. Using the shadow of a rotating black hole in a brane context in order to describe the M87* parameters recently announced by the Event Horizon Telescope Collaboration, the deviation from circularity of the reported shadow produces an upper bound on the bulk's nonlocal effect, which is conceived of as a tidal charge in the four-dimensional brane induced by the five-dimensional bulk. Therefore, a deviation from circularity $\lesssim 10\%$ leads to an upper bound on the tidal charge $\lesssim 0.004M^2$.Comment: 9 pages, 2 figures, 1 table. V2 with minor changes and new references. Published in The European Physical Journal

Non-agricultural land use and land reform: theory and evidence from Brazil

This paper examines the effect of nonagricultural land use on agrarian organization and land reform, providing a simple model to determine its policy implications and some evidence on its importance. It is argued that, if land-rental market is imperfect, there is a role for redistributive land policies and the following implications hold: (i) land reform is more probable to enhance efficiency in a low-wage economy; (ii) such policies should aim small farmers instead of landless people, obtaining land from large landholders. Empirical evidence suggests this is a relevant issue in Brazil, specially during periods of high macroeconomic instability.land reform; land use; agricultural development

Substrate specificity and the effect of calcium on Trypanosomabrucei metacaspase 2

Metacaspases are cysteine peptidases found only in yeast, plants and lower eukaryotes, including the protozoa. To investigate the extended substrate specificity and effects of Ca<sup>2+</sup> on the activation of these enzymes, detailed kinetic, biochemical and structural analyses were carried out on metacaspase 2 from Trypanosoma brucei (TbMCA2). These results reveal that TbMCA2 has an unambiguous preference for basic amino acids at the P<sub>1</sub> position of peptide substrates and that this is most probably a result of hydrogen bonding from the P<sub>1</sub> residue to Asp95 and Asp211 in TbMCA2. In addition, TbMCA2 also has a preference for charged residues at the P<sub>2</sub> and P<sub>3</sub>positions and for small residues at the prime side of a peptide substrate. Studies into the effects of Ca<sup>2+</sup> on the enzyme revealed the presence of two Ca<sup>2+</sup> binding sites and a reversible structural modification of the enzyme upon Ca<sup>2+</sup> binding. In addition, the concentration of Ca<sup>2+</sup> used for activation of TbMCA2 was found to produce a differential effect on the activity of TbMCA2, but only when a series of peptides that differed in P<sub>2</sub> were examined, suggesting that Ca<sup>2+</sup>activation of TbMCA2 has a structural effect on the enzyme in the vicinity of the S2 binding pocket. Collectively, these data give new insights into the substrate specificity and Ca<sup>2+</sup> activation of TbMCA2. This provides important functional details and leads to a better understanding of metacaspases, which are known to play an important role in trypanosomes and make attractive drug targets due to their absence in humans