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1.
Proc Natl Acad Sci U S A ; 118(25)2021 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-34161257

RESUMO

The Initial Upper Paleolithic (IUP) is a crucial lithic assemblage type in the archaeology of southwest Asia because it marks a dramatic shift in hominin populations accompanied by technological changes in material culture. This phase is conventionally divided into two chronocultural phases based on the Boker Tachtit site, central Negev, Israel. While lithic technologies at Boker Tachtit are well defined, showing continuity from one phase to another, the absolute chronology is poorly resolved because the radiocarbon method used had a large uncertainty. Nevertheless, Boker Tachtit is considered to be the origin of the succeeding Early Upper Paleolithic Ahmarian tradition that dates in the Negev to ∼42,000 y ago (42 ka). Here, we provide 14C and optically stimulated luminescence dates obtained from a recent excavation of Boker Tachtit. The new dates show that the early phase at Boker Tachtit, the Emirian, dates to 50 through 49 ka, while the late phase dates to 47.3 ka and ends by 44.3 ka. These results show that the IUP started in the Levant during the final stages of the Late Middle Paleolithic some 50,000 y ago. The later IUP phase in the Negev chronologically overlaps with the Early Upper Paleolithic Ahmarian of the Mediterranean woodland region between 47 and 44 ka. We conclude that Boker Tachtit is the earliest manifestation of the IUP in Eurasia. The study shows that distinguishing the chronology of the IUP from the Late Middle Paleolithic, as well as from the Early Upper Paleolithic, is much more complex than previously thought.

2.
PLoS One ; 12(1): e0169418, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28125597

RESUMO

Goda Buticha is a cave site near Dire Dawa in southeastern Ethiopia that contains an archaeological sequence sampling the late Pleistocene and Holocene of the region. The sedimentary sequence displays complex cultural, chronological and sedimentological histories that seem incongruent with one another. A first set of radiocarbon ages suggested a long sedimentological gap from the end of Marine Isotopic Stage (MIS) 3 to the mid-Holocene. Macroscopic observations suggest that the main sedimentological change does not coincide with the chronostratigraphic hiatus. The cultural sequence shows technological continuity with a late persistence of artifacts that are usually attributed to the Middle Stone Age into the younger parts of the stratigraphic sequence, yet become increasingly associated with lithic artifacts typically related to the Later Stone Age. While not a unique case, this combination of features is unusual in the Horn of Africa. In order to evaluate the possible implications of these observations, sedimentological analyses combined with optically stimulated luminescence (OSL) were conducted. The OSL data now extend the radiocarbon chronology up to 63 ± 7 ka; they also confirm the existence of the chronological gap between 24.8 ± 2.6 ka and 7.5 ± 0.3 ka. The sedimentological analyses suggest that the origin and mode of deposition were largely similar throughout the whole sequence, although the anthropic and faunal activities increased in the younger levels. Regional climatic records are used to support the sedimentological observations and interpretations. We discuss the implications of the sedimentological and dating analyses for understanding cultural processes in the region.


Assuntos
Arqueologia , Fósseis/diagnóstico por imagem , Sedimentos Geológicos/análise , Datação Radiométrica/métodos , Animais , Radioisótopos de Carbono , Cavernas , Etiópia , Fósseis/história , História Antiga , Humanos , Luminescência , Medições Luminescentes
3.
J Hum Evol ; 75: 53-63, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25200888

RESUMO

Grotte Vaufrey, located in the Dordogne region of southwestern France, is well known for its substantial archaeological sequence containing a succession of Acheulean and Mousterian occupations. While over the last thirty years numerous studies have attempted to outline a detailed chronostratigraphy for this important sequence, the failure to employ a common chronological framework has complicated its interpretation. Here, we aim to resolve these inconsistencies by providing a new chronology for the site based on luminescence dating. To this end, thermally-transferred optically stimulated luminescence (TT-OSL) dates were obtained from eight sediment samples distributed throughout the sequence, which, when combined with already available chronological information, produce a new chronostratigraphic model for the site. Our results demonstrate that the Typical Mousterian extends from MIS 7 to MIS 5, while the earliest Acheulean occupation could be associated with MIS 8 and may date to as early as MIS 10. When compared with other regional sequences, the Acheulean levels from the Grotte Vaufrey provide evidence for one of the earliest hominin occupations in southwestern France.


Assuntos
Sedimentos Geológicos/análise , Sedimentos Geológicos/química , Quartzo/química , Arqueologia , França , Datação Radiométrica
4.
Ginecol Obstet Mex ; 79(5): 303-7, 2011 May.
Artigo em Espanhol | MEDLINE | ID: mdl-21966820

RESUMO

The production of anti-müllerian hormone for the ovarian follicles begins near the puberty and the circulating levels begin to descend progressively in the stage of the pre-menopause coinciding with the depletion follicular and in consequence the menstrual cycles become irregular, frequently anovulatories. Therefore, concentration of anti-müllerian hormone shows a close correlation with follicular reserve and reproductive capacity, more than FSH and estradiol measurements. We described two patients that developed premature ovarian failure without previous diagnosis and therefore just were treated pharmacologically with estrogen-progestagen to induce menstrual bleeding. In blood of both patients was found low levels (< or = 4 ng/mL) of anti-müllerian hormone, and by means of sonography the absence of follicles was demonstrated in the ovaries. Has intended that premature ovarian failure could be of a chromosomal dysfunction, similar to other gonadal dysgenesias, another explanation of the mechanism is that it could be for development of some autoimmunity dysfunction. Therefore, the combined hormonal substitution of estrogen with progestagen should stay during several years to avoid the complications for the lack of estrogens; in some cases, could be informed on offering the pregnancy possibility by means of the attended fertilization using ovules donor.


Assuntos
Hormônio Antimülleriano/sangue , Menopausa Precoce/sangue , Adulto , Biomarcadores , Estradiol/sangue , Estrogênios/uso terapêutico , Feminino , Hormônio Foliculoestimulante/sangue , Terapia de Reposição Hormonal , Humanos , Infertilidade Feminina/etiologia , Ovário/diagnóstico por imagem , Progestinas/uso terapêutico , Ultrassonografia
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