Migration,rank-size distribution,and economic development: The case of Mexico

This is an examination of whether city size is truly an independent variable when the relationships between city size and certain economic and social phenomena are considered. A new hypothesis is presented that postulates that relative or systemic city size is an independent variable that affects urban growth patterns through varying, non-optimum migration flows. The hypothesis is tested using official Mexican data for the period 1960 to 1970.     

Slim just left town: decisionmaking on an intensive care unit

The title of this paper comes from an incident that occurred while I was participating in morning rounds on the pediatric and surgical intensive care unit of a large, midwest tertiary care center. The patient under discussion was an eight-week-old girl who had been born without kidneys, and who had been cared for on the unit for seven weeks. In the previous week, the baby's condition had gone steadily downhill, as she experienced on medical catastrophe after another. One of the nurses asked the staff doctor who was leading rounds that morning, "What are the baby's chances?" The physician replied, "Her chances are slim." To which one of the young residents immediately answered, "Slim just left town."     

Genetic markers in human bone: I. Deoxyribonucleic acid (DNA) analysis.

Deoxyribonucleic acid (DNA) was isolated from a number of spongy and compact human bone tissue specimens, and the yield was estimated on a "per milligram of starting tissue" basis. DNA was, in addition, isolated from a number of corresponding blood and bone tissue specimens. Spectrophotofluorometry and ethidium bromide visualization on minigels were used to estimate the quantity and degree of degradation of DNA. The DNA from several blood-bone pairs is shown to give concordant restriction fragment length polymorphism (RFLP) typing results by two different typing protocols with five different single-locus probes. DNA from several additional blood-bone pairs is shown to give concordant results for human leucocyte antigen (HLA)-DQ alpha phenotypes following polymerase chain reaction (PCR) amplification and hybridization to specific allele-specific oligonucleotide (ASO) probes, and for the variable numbers of tandem repeats (VNTR) length polymorphisms 3' to the human apolipoprotein B (APOB) gene following PCR amplification with specific primers and analysis of the products by electrophoresis and ethidium bromide visualization.