Genetic diversity and population parameters of sea otters, Enhydra lutris, before fur trade extirpation from 1741-1911.

All existing sea otter, Enhydra lutris, populations have suffered at least one historic population bottleneck stemming from the fur trade extirpations of the eighteenth and nineteenth centuries. We examined genetic variation, gene flow, and population structure at five microsatellite loci in samples from five pre-fur trade populations throughout the sea otter's historical range: California, Oregon, Washington, Alaska, and Russia. We then compared those values to genetic diversity and population structure found within five modern sea otter populations throughout their current range: California, Prince William Sound, Amchitka Island, Southeast Alaska and Washington.

Energetics of nose and mouth breathing, body size, body composition, and nose volume in young adult males and females.

This research tests the relative ability of body size factors and sex to explain variation in nose volume and to explain metabolic measures during rest and moderate exercise in 50 young adults. It uses standard anthropometric measures plus two new measures of nose morphology (nose/face angle and nose volume) and evaluates body composition with a device for air displacement plethysmography. Standard physiological measures were obtained in nose-only and mouth-only breathing conditions with subjects at rest and using moderate exercise.

Using stable isotope analysis to obtain dietary profiles from old hair: a case study from Plains Indians.

Stable isotope composition of human tissue reflects that of foods consumed, and can provide information about diet independent of artifactual remains. Here we refine and test this method by analyzing nitrogen (delta(15)N) and carbon (delta(13)C) isotope ratios in historic North American Plains Indians hair. Gas-source isotope-ratio mass spectrometry provides high-precision data for both delta(15)N and delta(13)C (+/-0.

An energetics-based approach to understanding the menstrual cycle and menopause.

To explain the menstrual cycle and menopause, human biologists during the past several decades have developed new models of the evolutionary origins and maintenance of female reproductive patterns that address both ultimate and proximate causation. Hypotheses proposed for these processes generally offer explanations for menstruation or for menopause, but not for both; ultimately, these explanations must be integrated. Reviewing current explanations, this paper offers an energetics-based evolutionary rationale compatible with past adaptations of Homo sapiens and with ecological patterns in small-scale, preindustrial social systems in which food resources vary and sometimes are scarce.

Continuous Infusion Ranitidine in Postoperative Pediatric Liver Transplant Patients: Effects on Intragastric pH, Gastrointestinal Bleeding and Metabolic Alkalosis.

The effects of ranitidine, an H(2)-receptor antagonist, on gastric pH, incidence of upper gastrointestinal hemorrhage and postoperative metabolic alkalosis were evaluated in 23 pediatric liver transplant recipients. Intragastric pH probes were inserted postoperatively and pH was monitored for 48 h. Ranitidine was infused for 48 h at 0.