Post-marital residence patterns and the timing of reproduction: evidence from a matrilineal society.

Humans exhibit a broad range of post-marital residence patterns and there is growing recognition that post-marital residence predicts women's reproductive success; however, the nature of the relationship is probably dependent on whether co-resident kin are cooperators or competitors. Here, we explore this relationship in a Tibetan population, where couples practice a mixture of post-marital residence patterns, co-residing in the same village with the wife's parents, the husband's parents or endogamously with both sets of parents. Using detailed demographic data from 17 villages we find that women who live with only their own parents have an earlier age at first birth (AFB) and age at last birth (ALB) than women who live with only their parents-in-law. Women who co-reside with both sets of parents have the earliest AFB and ALB. However, those with co-resident older siblings postponed reproduction, suggestive of competition-related delay. Shifts to earlier reproductive timing were also observed in relation to the imposition of family planning policies, in line with Fisherian expectations. Our study provides evidence of the costs and benefits to women's direct fitness of co-residing with different kin, against a backdrop of adaptive responses to cultural constraints on completed fertility.

Thermoelectric Performance of Se/Cd Codoped SnTe via Microwave Solvothermal Method.

Extensive attention has been focused on thermoelectric performance optimization of SnTe because of its potential in waste heat recovery. Here, we fabricate high thermoelectric performance Se/Cd codoped SnTe octahedral particles by microwave-stimulated solvothermal method. The SnTe-based octahedral particles have sizes ranging from several micrometers to hundreds of nanometers, forming dense bulks after spark plasma sintering. Combined with the strong point defect scattering by Se and Cd dopants, a low thermal conductivity of 1.8 W m-1 K-1 at 773 K is obtained in the Se/Cd codoped Sn0.98Cd0.02Te0.9Se0.1 sample. Se and Cd dopants can optimize the band structure of SnTe and boost the power factors, resulting in a promising peak ZT of ∼0.78 at 773 K in the Se/Cd codoped Sn0.98Cd0.02Te0.9Se0.1 sample, which is significantly higher than those of undoped SnTe and Se-doped SnTe samples.