Oxygen isotope fractionation between bird eggshell calcite and body water: application to fossil eggs from Lanzarote (Canary Islands).

Oxygen and carbon isotope compositions of fossil bird eggshell calcite (δ(18)Ocalc and δ(13)Ccalc) are regularly used to reconstruct paleoenvironmental conditions. However, the interpretation of δ(18)Ocalc values of fossil eggshells has been limited to qualitative variations in local climatic conditions as oxygen isotope fractionations between calcite, body fluids, and drinking water have not been determined yet. For this purpose, eggshell, albumen water, and drinking water of extant birds have been analyzed for their oxygen and carbon isotope compositions.

The earliest pigeon fanciers.

Feral Pigeons have colonised all corners of the Earth, having developed a close association with humans and their activities. The wild ancestor of the Feral Pigeon, the Rock Dove, is a species of rocky habitats, nesting typically on cliff ledges and at the entrance to large caves. This habit would have brought them into close contact with cave-dwelling humans, a relationship usually linked to the development of dwellings in the Neolithic.

[Conflict areas in two psychotherapeutic groups of climacteric women].

Background: An important consideration is to specify the areas of conflict that will be worked on during the psychotherapeutic process in order to develop a specific psychological model for a group intervention with menopausal women.

Objective: To determine the most relevant areas of psychological conflict for women in the menopausal stage by means of a focalization technique.

Patients And Method: A descriptive, cross-sectional, longitudinal study with non-experimental design was done in 29 patients from the Perinatology National Institute of Mexico (INPer).