David Martin’s Forbidden Revolutions

Technological Revolutions

In skill-biased (de-skilling) technological revolutions learning investments required by new machines are greater (smaller) than those required by preexisting machines. Skill-biased (de-skilling) revolutions trigger reallocations of capital from slow(fast-) to fast(slow-) learning workers, thereby reducing the relative and absolute wages of the former. The model of skill-biased (de-skilling) re...

217-223 Martins LAJP 1428

1 Department of Clinical and Toxicological Analysis, University of Alfenas-MG, Av. Gabriel Monteiro da Silva, 714, Alfenas, MG, Brazil, 37130.000 2 Laboratory of Industrial Hygiene and Toxicology, University of Brescia, P.le Spedali Civili, 1, 25100, Brescia, Italy 3 Department of Clinical and Toxicological Analysis, Faculty of Pharmaceutical Sciences, University of São Paulo, Av. Lineu Prestes...

Philosophical Revolutions

Purple Martins in Oak Woodlands

Purple martins are cavity-nesting swallows that once nested fairly widely in California’s oak woodlands but are now rare in that habitat. The old oaks of the Tehachapi Range (southern Sierra Nevada) may now host the last martins that nest in oak woodlands, with approximately 100-200 pairs or about 15 percent of the California population. In summer of 2000, we found 57 nests in 46 valley and blu...

Oogenesis: Matrix Revolutions

The mechanism of egg-chamber elongation during Drosophila oogenesis has always been mysterious. A new study shows that the egg chambers spin around their long axis laying down polarised extracellular matrix, which acts as a molecular corset to restrict radial expansion.