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1.
Nature ; 548(7667): 322-325, 2017 08 17.
Artículo en Inglés | MEDLINE | ID: mdl-28792933

RESUMEN

Genetic evidence for anatomically modern humans (AMH) out of Africa before 75 thousand years ago (ka) and in island southeast Asia (ISEA) before 60 ka (93-61 ka) predates accepted archaeological records of occupation in the region. Claims that AMH arrived in ISEA before 60 ka (ref. 4) have been supported only by equivocal or non-skeletal evidence. AMH evidence from this period is rare and lacks robust chronologies owing to a lack of direct dating applications, poor preservation and/or excavation strategies and questionable taxonomic identifications. Lida Ajer is a Sumatran Pleistocene cave with a rich rainforest fauna associated with fossil human teeth. The importance of the site is unclear owing to unsupported taxonomic identification of these fossils and uncertainties regarding the age of the deposit, therefore it is rarely considered in models of human dispersal. Here we reinvestigate Lida Ajer to identify the teeth confidently and establish a robust chronology using an integrated dating approach. Using enamel-dentine junction morphology, enamel thickness and comparative morphology, we show that the teeth are unequivocally AMH. Luminescence and uranium-series techniques applied to bone-bearing sediments and speleothems, and coupled uranium-series and electron spin resonance dating of mammalian teeth, place modern humans in Sumatra between 73 and 63 ka. This age is consistent with biostratigraphic estimations, palaeoclimate and sea-level reconstructions, and genetic evidence for a pre-60 ka arrival of AMH into ISEA. Lida Ajer represents, to our knowledge, the earliest evidence of rainforest occupation by AMH, and underscores the importance of reassessing the timing and environmental context of the dispersal of modern humans out of Africa.


Asunto(s)
Cuevas , Fósiles , Migración Humana/historia , Espectroscopía de Resonancia por Spin del Electrón , Historia Antigua , Humanos , Indonesia , Luminiscencia , Bosque Lluvioso , Diente/anatomía & histología , Uranio
2.
Mar Pollut Bull ; 96(1-2): 356-67, 2015 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-25935807

RESUMEN

Terrestrial runoff and flooding have resulted in major impacts on coral communities worldwide, but we lack detailed understanding of flood plume conditions and their ecological effects. Over the course of repeated flooding between 2010 and 2013, we measured coral cover and water quality on the high-latitude coral reefs of Hervey Bay, Queensland, Australia. In 2013, salinity, total suspended solids, total nitrogen and total phosphorus were altered for up to six months post-flooding. Submarine groundwater caused hypo-saline conditions for a further four months. Despite the greater magnitude of flooding in 2013, declines in coral abundance (∼28%) from these floods were lower than the 2011 flood (∼40%), which occurred immediately after a decade of severe drought. There was an overall cumulative decrease of coral by ∼56% from 2010 to 2013. Our study highlights the need for local scale monitoring and research to facilitate informed management and conservation of catchments and marine environments.


Asunto(s)
Antozoos/fisiología , Arrecifes de Coral , Monitoreo del Ambiente , Inundaciones/estadística & datos numéricos , Contaminantes Químicos del Agua/análisis , Animales , Bahías/química , Nitrógeno/análisis , Fósforo/análisis , Queensland , Lluvia , Salinidad , Calidad del Agua
3.
J Hum Evol ; 57(5): 484-502, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19254806

RESUMEN

A robust timeframe for the extant cave deposits at Liang Bua, and for the river terraces in the adjoining Wae Racang valley, is essential to constrain the period of existence and time of extinction of Homo floresiensis and other biota that have been excavated at this hominin type locality. Reliable age control is also required for the variety of artifacts excavated from these deposits, and to assist in environmental reconstructions for this river valley and for the region more broadly. In this paper, we summarize the available geochronological information for Liang Bua and its immediate environs, obtained using seven numerical-age methods: radiocarbon, thermoluminescence, optically- and infrared-stimulated luminescence (collectively known as optical dating), uranium-series, electron spin resonance, and coupled electron spin resonance/uranium-series. We synthesize the large number of numerical age determinations reported previously and present additional age estimates germane to questions of hominin evolution and extinction.


Asunto(s)
Evolución Biológica , Fenómenos Geológicos , Hominidae/genética , Ríos , Animales , Fósiles , Historia Antigua , Hominidae/clasificación , Humanos , Indonesia , Uranio
4.
Zhongguo Zhong Xi Yi Jie He Za Zhi ; 21(10): 760-2, 2001 Oct.
Artículo en Chino | MEDLINE | ID: mdl-12575611

RESUMEN

OBJECTIVE: To study the mechanism of anti-tumor effect of Fuzheng Yiliu Decoction (FZYLD). METHODS: S180 neoplasm strain was inoculated in Kunming mice to establish model of S180 solid tumor. The model animals were treated with FZYLD by gastrogavage, the cell cycle of tumor were checked up by flow cytometer and the telomerease kit was used to test telomerease activity. RESULTS: The stage G0/1 ratio of tumor cells in model animals treated with FZYLD increased, while cells of S stage decreased, with telomerease activity inhibited. These changes were different significantly from those in the model animals treated with normal saline (P < 0.001). CONCLUSION: FZYLD could block the tumor cell proliferation procedure and inhibit the DNA synthesis and duplication in tumor cell. And the suppression of telomerease activity might be one of the mechanisms affecting the tumor cell proliferation cycle.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Medicamentos Herbarios Chinos/farmacología , Sarcoma 180/enzimología , Sarcoma 180/patología , Telomerasa/metabolismo , Animales , Ciclo Celular/efectos de los fármacos , ADN de Neoplasias/biosíntesis , Femenino , Masculino , Ratones
5.
World J Gastroenterol ; 3(3): 185-8, 1997 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-27239147

RESUMEN

AIM: To demonstrate the relationship between the ultrastructural changes of the gastric mucosa and the syndrome differentiation in chronic gastritis. METHODS: Sixteen chronic gastritis patients with Piweixuhan (PXG, the cold of insufficiency syndrome of the spleen and the stomach) and fifteen chronic gastritis patients with Ganweibuhe (GBG, incoordination syndrome of the liver and the stomach) were treated with Jianpiwenwei decoction (JWD, invigorating the spleen and warming the stomach) or Shuganhewei decoction (SHD, dispersing the stagnated Liver Qi and regulating the stomach), respectively for three months. Before and after treatment, a gastroscopy was performed and the gastric mucosa was collected from the lesser curvature of the antrum of each patient. The ultrasections were observed and photographed under the JEM-100C X electron microscope. RESULTS: The common ultrastructural anomalies of the two types of chronic gastritis were the plasmacyte infiltration and the lesions of the mucosal epithelial cells, chief cells and antral mucous cells. There were obvious differences between the two types. In PXG, the predominant lesion of the chief cells was swelling of the mitochondria, while in GBG the rough endoplasmic reticulum was enlarged in the chief cells and the plasmacytes. After treatment, most cases of the ultrastructural lesions reverted to normal or improved. CONCLUSION: There was a close relationship between the ultrastructural changes of gastric mucosa and the syndrome differentiation of chronic gastritis. JWD and SHD could significantly improve the ultrastructural lesions of the gastric mucosa.

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