Congenital Aortic Stenosis: Some Observations on the Natural History and Clinical Assessment

Three hundred patients, 30 years of age or under, with the clinical diagnosis of aortic stenosis were reviewed to provide information on the accuracy of clinical assessment and the natural history of the condition when left untreated. Sudden death was uncommon and occurred only in patients with clinical evidence of severe obstruction. In infants, the early presentation and lethal nature of aortic stenosis appeared to result from the presence of additional cardiac lesions. Correlation of clinical assessment with hemodynamic data in 83 patients indicated that important stenosis was present if the systolic murmur was accompanied by a thrill and associated with an increased left ventricular impulse, decreased brachial artery pulse pressure, or left ventricular hypertrophy on the electrocardiogram. The site of obstruction could not be established with certainty by clinical examination, but an early systolic ejection click was strong evidence against subvalvular stenosis.     

Maya Zapatistas Move to the Ancient Future

This essay assesses recent events pertaining to the Maya Zapatista movement in light of the Mesoamerican past and present. Persistent patterns of Maya world construction, group and personal identity, and political legitimacy form the conceptual core of the movement, expressing themes that have been well documented for some 2,000 years in Maya cultural history. The essay concludes with suggestions as to the new forms that pan-Maya ethnic affirmation may assume in the multiethnic configuration of Mexico and Guatemala in the 21st century.     

Porotic Hyperostosis and Paleoepidemiology: A Forensic Perspective on Anemia among the Ancient Maya

Porotic lesions caused by childhood anemia are commonly found on ancient Maya crania and have been cited as evidence for extremely poor nutrition during the Classic Period. We reconsider this characterization in the light of recent data on childhood anemia in rural Guatemala and the prevalence of porotic hyperostosis in crania of forensic skeletal remains of rural highland Maya from Plan de Sanchez, Baja Verapaz, which date to 1982. The abundance of porotic hyperostosis in adults from Plan de Sanchez fits well with the number of modern rural children suffering from anemia, but the lesions are very rare compared to archaeological series. Although some minor change in diet and infection may contribute to differences in porotic hyperostosis, it is likely that higher mortality leads to fewer anemic lesions in modern adult crania. We hypothesize that more anemic children survived to adulthood in the past than do today, [iron-deficiency anemia, porotic hyperostosis, Maya, nutrition, forensic anthropology, osteological paradox]     

Dynamic Model for Life History of Scyphozoa

A two-state life history model governed by ODEs is formulated to elucidate the population dynamics of jellyfish and to illuminate the triggering mechanism of its blooms. The polyp-medusa model admits trichotomous global dynamic scenarios: extinction, polyps survival only, and both survival. The population dynamics sensitively depend on several biotic and abiotic limiting factors such as substrate, temperature, and predation. The combination of temperature increase, substrate expansion, and predator diminishment acts synergistically to create a habitat that is more favorable for jellyfishes. Reducing artificial marine constructions, aiding predator populations, and directly controlling the jellyfish population would help to manage the jellyfish blooms. The theoretical analyses and numerical experiments yield several insights into the nature underlying the model and shed some new light on the general control strategy for jellyfish.     

The Machete and the Cross: Campesino Rebellion in Yucatan: The Conquest of the Last Maya Kingdom: Río Azul: An Ancient Maya City

The Machete and the Cross: Campesino Rebellion in Yucatan. Don E. Dumond. Lincoln: University of Nebraska Press, 1997.571pp.
The Conquest of the Last Maya Kingdom. Grant D. Jones. Stanford, CA: Stanford University Press, 1998.568 pp.
Río Azul: An Ancient Maya City. Richard E. W. Adams. Norman: University of Oklahoma Press, 1999. 238 pp.