335 research outputs found
How Mitochondrial DNA Can Write Pre-History: Kinship and Culture in Duero Basin (Spain) during Chalcolithic and Bronze Age
The chronological period from the beginning of the Chalcolithic Age to the end of the Bronze Age on the Iberian northern sub-plateau of the Iberic Peninsula involves interesting social and cultural phenomena, such as the appearance of the Bell Beaker and, later, the Cogotas I cultures. This work constructs a genetic characterisation of the maternal lineages of the human population that lived on the northern sub-plateau between 5000 and 3000 years ago through an analysis of mitochondrial DNA (mtDNA), a kind of genetic marker that is inherited through maternal lineages, unaltered from generation to generation. Population and cultural questions are investigated through mtDNA analyses. This study intends to shed light on the following questions. Were individuals who were buried together in multiple or collective burials biologically related through their maternal lineages? Were there distinct maternal human lineages in the same or different geographical areas if different material cultures (Bell Beaker and Cogotas I) were associated with the arrival of new human populations who established close biological relationships with the endogenous populations? Or could this be the result of the transmission of knowledge without human populations mixing? Another important question is whether the material cultures were related to the female populations. We analysed 91 individuals from 28 different archaeological sites of the Iberian northern sub-plateau from four different chrono-cultural periods (Pre-Bell Beaker, Bell Beaker, Proto-Cogotas I, and Cogotas I), from the end of the Chalcolithic Age up to the Bronze Age. There were two historical moments of new populations arriving: the first during the Pre-Bell Beaker period, associated with the K mtDNA haplogroup, and the second during the Proto-Cogotas I culture, with new lineages of the H, HVO, and T haplogroups. Neither of these new population flows were directly associated with the maximum development of the two main material cultures Bell Beaker and Cogotas I, so they must have occurred immediately beforehand, during the Pre-Bell Beaker and Proto-Cogotas I periods, respectively. However, we cannot discard an association between the populations and material cultures. Curiously, it has also been observed that there was also a tendency towards multiple burials, in which the individuals who were buried together belonged to the same maternal lineage, during these two periods of population change. This study has shed some light on the populational changes that occurred through these different periods in this specific geographical area of the northern sub-plateau of the Iberian Peninsula
Family History in the Iberian Peninsula during Chalcolithic and Bronze Age: An Interpretation through the Genetic Analysis of Plural Burials
Throughout history, it has been observed that human populations have buried the deceased members of their communities following different patterns. During the Copper Age and the Bronze Age-periods on which this study focuses-in the northern sub-plateau of the Iberian Peninsula, we identified different patterns of multiple or collective burial. This work analyzes a total of 58 individuals buried in different multiple or collective graves, to investigate whether the practice of these burials implies a family or biological link between individuals buried together. With this aim, STR markers of nuclear DNA were analyzed, as well as the hypervariable regions I and II of mitochondrial DNA, establishing both close kinship relationships and relationships through maternal lineage. We observed different burial patterns, detecting certain maternal lines preserved in some common burials maintained over time. Close family relationships were observed to a lesser extent, with some occasional exceptions. The results of the analysis formed the basis for a discussion on the concepts of family and community
Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV
The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8 TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum
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