How strong was the bottleneck associated to the peopling of the Americas? New insights from multilocus sequence data.

In spite of many genetic studies that contributed for a deep knowledge about the peopling of the Americas, no consensus has emerged about important parameters such as the effective size of the Native Americans founder population. Previous estimates based on genomic datasets may have been biased by the use of admixed individuals from Latino populations, while other recent studies using samples from Native American individuals relied on approximated analytical approaches. In this study we use resequencing data for nine independent regions in a set of Native American and Siberian individuals and a full-likelihood approach based on isolation-with-migration scenarios accounting for recent flow between Asian and Native American populations.

Lifestyle mediates seasonal changes in metabolic health among the yakut (sakha) of northeastern siberia.

Objectives: Among indigenous circumpolar populations, extreme seasonality influences food availability and energy metabolism. Furthermore, subsistence patterns and wage labor opportunities shift with season. Thus, health measures among circumpolar populations likely exhibit seasonal changes that are influenced by lifestyle factors.

Adiponectin, hemoglobin, and cardiovascular risk in an indigenous siberian population.

Objectives: Adipose tissue hypoxia appears to play a role in promoting chronic inflammation and the development of obesity-related cardiovascular and metabolic diseases, yet the underlying mechanisms are not well understood. The aim of the present research is to examine whether adiponectin levels (an adipocyte-derived hormone with anti-inflammatory properties) are inversely correlated with hemoglobin levels in an indigenous Siberian population.

Methods: The study was conducted among 252 Yakut adults (≥18 years; 135 females) from Berdygestiakh, Sakha Republic, Russia.

Do physical activity and sedentary behavior relate to cardio-metabolic risk factor clustering in indigenous Siberian adults?

Objectives: To investigate whether having multiple risk factors for cardio-metabolic disease is associated with objectively measured physical activity or sedentary behavior within a sample of Yakut (Sakha) of Siberia.

Methods: This cross sectional study involved 63 Yakut adults (32 men) who were measured for cardio-metabolic risk factors. Free living physical activity and sedentary behavior were calculated from waist accelerometry.

Seasonal variation in basal metabolic rates among the Yakut (Sakha) of Northeastern Siberia.

Objectives: Previous research has shown that indigenous circumpolar populations have elevated basal metabolic rates (BMRs), yet few studies have explored whether metabolic rates increase during the winter. This study addresses this gap by examining seasonal variation in BMR and its associations with thyroid function and lifestyle factors among the Yakut (Sakha) of Siberia.

Methods: Anthropometric dimensions, BMR, and thyroid hormone levels (free triiodothyronine [fT3], free thyroxine [fT4], thyroid-stimulating hormone [TSH]) were measured on two occasions (July/August, 2009 and January 2011) on a sample of 94 Yakut (Sakha) adults (35 men, 59 women) from the rural village of Berdygestiakh, Sakha Republic, Russia.