Origins, Admixture Dynamics, and Homogenization of the African Gene Pool in the Americas

The Transatlantic Slave Trade transported more than 9 million Africans to the Americas between the early 16th and the mid-19th centuries. We performed a genome-wide analysis using 6,267 individuals from 25 populations to infer how different African groups contributed to North-, South-American, and Caribbean populations, in the context of geographic and geopolitical factors, and compared genetic data with demographic history records of the Transatlantic Slave Trade. We observed that West-Central Africa and Western Africa-associated ancestry clusters are more prevalent in northern latitudes of the Americas, whereas the South/East Africa-associated ancestry cluster is more prevalent in southern latitudes of the Americas. This pattern results from geographic and geopolitical factors leading to population differentiation. However, there is a substantial decrease in the between-population differentiation of the African gene pool within the Americas, when compared with the regions of origin from Africa, underscoring the importance of historical factors favoring admixture between individuals with different African origins in the New World. This between-population homogenization in the Americas is consistent with the excess of West-Central Africa ancestry (the most prevalent in the Americas) in the United States and Southeast-Brazil, with respect to historical-demography expectations. We also inferred that in most of the Americas, intercontinental admixture intensification occurred between 1750 and 1850, which correlates strongly with the peak of arrivals from Africa. This study contributes with a population genetics perspective to the ongoing social, cultural, and political debate regarding ancestry, admixture, and the mestizaje process in the Americas.

Peruvian psychiatry in America and the world: its journey in search of an identity

Throughout history, Latin American psychiatry has followed a variety of routes as its mythic-religious origins experienced the various influences of European and North American ideas of the last three centuries. In its modern trajectory, a post-colonial subordination was followed by a more selective import of ideas and a critical approach to their application in the New Continent. At one point, the identity of Latin American psychiatry was essentially considered mestiza, social and critical, reflecting a search for autonomy and originality. In this journey, Peruvian psychiatry has been considered one of the most representative versions of the history and position of the discipline. This article attempts to detail the identity-seeking process of Peruvian and Latin American Psychiatry through the life and work of three notable Peruvian figures: Honorio Delgado, Carlos Alberto Seguín and Humberto Rotondo. Delgado fostered the need for scientific evidence in support of any piece of knowledge, as well as humanism as essential component of best service and optimal patient care. Seguín led studies on folkloric and ethnic psychiatry, stimulated integrated approaches to care, and advocated in favour of a regional identity for psychiatry.

Medicinal use of wild fauna by mestizo communities living near San Guillermo Biosphere Reserve (San Juan, Argentina)

BACKGROUND

Wild and domestic animals and their by-products are important ingredients in the preparation of curative, protective and preventive medicines. Despite the medicinal use of animals worldwide, this topic has received less attention than the use of medicinal plants. This study assessed the medicinal use of animals by mestizo communities living near San Guillermo MaB Reserve by addressing the following questions: What animal species and body parts are used? What ailments or diseases are treated with remedies from these species? To what extent do mestizo people use animals as a source of medicine? Is the use related to people's age?

METHODS

We conducted semi-structured interviews with 171 inhabitants (15-93 years old) of four villages close to the Reserve: Tudcúm, Angualasto, Malimán and Colangüil. We calculated the informant consensus factor and fidelity level to test homogeneity of knowledge and to know the importance of different medicinal uses for a given species.

RESULTS

The medicinal use of animals was reported by 57% of the surveyed people. Seven species were mentioned: Rhea pennata, Lama guanicoe, Puma concolor, Pseudalopex sp., Lama vicugna, Lepus europaeus and Conepatus chinga. Several body parts were used: fat, leg, bezoar-stone, stomach, feather, meat, blood, feces, wool, and liver. The fat of R. pennata was the most frequently used animal part, followed by the bezoar stone and the leg of L. guanicoe. Animals were used to treat 22 ailments, with respiratory and nervous system disorders being the most frequently treated diseases with a high degree of consensus. Old people used animals as remedies more frequently than young residents, showing some differences among villages.

CONCLUSIONS

A low number of animal species was mentioned as used for medicinal purposes, which could be explained by the perception of strong control related the legislation that bans hunting and the erosion of traditional knowledge produced by mestizaje. However, the presence of a traditional medicine is deeply rooted in the community culture. Management strategy for protected areas should focus not only on the conservation and sustainability of biological resources, but also on the ancestral knowledge of local communities, such as the medicinal use of animals.