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Few phenomena have had as profound or long-lasting consequences in human history as the emergence of large-scale centralized states in the place of smaller scale and more local societies. This study examines a fundamental, and yet unexplored, consequence of state formation: its genetic legacy. We studied the genetic impact of state centralization during the formation of the eminent precolonial Kuba Kingdom of the Democratic Republic of the Congo (DRC) in the 17th century. We analyzed genome-wide data from over 690 individuals sampled from 27 different ethnic groups from the Kasai Central Province of the DRC. By comparing genetic patterns in the present-day Kuba, whose ancestors were part of the Kuba Kingdom, with those in neighboring non-Kuba groups, we show that the Kuba today are more genetically diverse and more similar to other groups in the region than expected, consistent with the historical unification of distinct subgroups during state centralization. We also found evidence of genetic mixing dating to the time of the Kingdom at its most prominent. Using this unique dataset, we characterize the genetic history of the Kasai Central Province and describe the historic late wave of migrations into the region that contributed to a Bantu-like ancestry component found across large parts of Africa today. Taken together, we show the power of genetics to evidence events of sociopolitical importance and highlight how DNA can be used to better understand the behaviors of both people and institutions in the past.

State centralization occurs when previously separate communities are united, forming a single political system often associated with economy, trade, warfare, and culture. One example is the precolonial Kuba Kingdom of the Democratic Republic of the Congo (DRC). Using genetic data from over 690 individuals from the DRC, we compared individuals whose ancestors were part of the Kingdom to individuals from other neighboring groups. We found a genetic legacy of state formation that can be explained by the joining and subsequent mixing of groups at the time of state centralization, as well as evidence of gene flow facilitated by the Kingdom's infrastructure. We characterize the genetic history of this region and show the power of DNA to reveal information on societal systems where few written records exist.

This paper approaches the energy transition towards decarbonization and lower primary energy use in the steel and glass industries through the exploitation of radiant waste heat. In contrast with exhaust gases heat recovery, radiant waste heat has typically not been used. This energy waste is found in energy intensive processes in which high temperatures are reached. For instance, in the steel making process, the cast steel is red hot and emits a considerable amount of radiant energy. In this paper the conceptual design of a radiant heat capturing device is presented. This device enables the recovery of currently unused energy while solving the radiative emission-related problems. The achieved design gets to an optimized solution regarding view factors and optical properties of the involved surfaces. In this research work, those factors are optimized to maximize the amount of heat recovered by the presented device. Simulation tools are used to test different designs and define the most appropriate solution for a given case. ; This work has been performed under BEROA-GO project (Waste Heat Collection from Solids for Efficient and Competitive Use), granted by the Basque Government (Spain), exp. KK-2017/00060.

In humans, the geographical apportionment of the coding diversity of the pigmentary locus melanocortin-1 receptor (MC1R) is, unusually, higher in Eurasians than in Africans. This atypical observation has been interpreted as the result of purifying selection due to functional constraint on MC1R in high UV-B radiation environments. By analyzing 3,142 human MC1R alleles from different regions of Spain in the context of additional haplotypic information from the 1000 Genomes (1000G) Project data, we show that purifying selection is also strong in southern Europe, but not so in northern Europe. Furthermore, we show that purifying and positive selection act simultaneously on MC1R. Thus, at least in Spain, regions at opposite ends of the incident UV-B radiation distribution show significantly different frequencies for the melanoma-risk allele V60L (a mutation also associated to red hair and fair skin and even blonde hair), with higher frequency of V60L at those regions of lower incident UV-B radiation. Besides, using the 1000G south European data, we show that the V60L haplogroup is also characterized by an extended haplotype homozygosity (EHH) pattern indicative of positive selection. We, thus, provide evidence for an adaptive value of human skin depigmentation in Europe and illustrate how an adaptive process can simultaneously help to maintain a disease-risk allele. In addition, our data support the hypothesis proposed by Jablonski and Chaplin (Human skin pigmentation as an adaptation to UVB radiation. Proc Natl Acad Sci U S A. 2010;107:8962-8968), which posits that habitation of middle latitudes involved the evolution of partially depigmented phenotypes that are still capable of suitable tanning. ; This works was supported by the former Spanish Ministerio de Ciencia e Innovación, project CGL2008-04066/BOS to S.A.; by the Dpt. Educacion, Universidades e Investigación of the Basque Government, project IT542-10; by program UFI11/09 by the University of the Basque Country, by "Programa de Investigacion Cientifica de la Universidad de La Laguna" (boc-a- 2010-255-7177), and by grants from the Health Institute "Carlos III" (FIS PI08/1383, FIS PI11/00623) to C.F. and co-financed by the European Regional Development Funds, "A way of making Europe" from the European Union. M.P.Y. was supported by a postdoctoral fellowship from Fundación Ramón Areces. We thank the Spanish Banco Nacional de AND (BNADN) (http://www.bancoadn.org/) for providing us with DNA samples from all over Spain. We also thank the Spanish Agencia Estatal de Meteorología (AEMET) (http://www.aemet.es/) for kindly providing us with the UV-B radiation data.