ABSTRACT
Abstract Traditionally dates is consumed as a rich source of iron supplement and the current research discuss the synthesis of silver nanoparticles (AgNPs) using methanolic seed extract of Rothan date and its application over in vitro anti-arthritic, anti-inflammatory and antiproliferative activity against lung cancer cell line (A549). FTIR result of synthesised AgNPs reveals the presence of functional group OH as capping agent. XRD pattern confirms the crystalline nature of the AgNPs with peaks at 38º, 44º, 64º and 81º, indexed by (111), (200), (220) and (222) in the 2θ range of 10-90, indicating the face centered cubic (fcc) structure of metallic Ag. HR- TEM results confirm the morphology of AgNPs as almost spherical with high surface areas and average size of 42 ± 9nm. EDX spectra confirmed that Ag is only the major element present and the Dynamic light scattering (DLS) assisted that the Z-average size was 203nm and 1.0 of PdI value. Zeta potential showed − 26.5mv with a single peak. The results of the biological activities of AgNPs exhibited dose dependent activity with 68.44% for arthritic, antiinflammatory with 63.32% inhibition and anti-proliferative activity illustrated IC50 value of 59.66 µg/mL expressing the potential of AgNPs to combat cancer
Subject(s)
Silver , In Vitro Techniques/methods , Chronology as Topic , Nanoparticles , Phoeniceae/adverse effects , Lung Neoplasms/classification , Seeds , zeta Potential , Spectroscopy, Fourier Transform Infrared , Inhibitory Concentration 50 , Dosage/methodsABSTRACT
An extract of date (fruit of a palm tree) residue plus food-grade glutamate, acetic acid, and yeast extract (date residue extract mix, DREM) has been successfully fermented with using Lactobacillus brevis JCM 1059T to produce gamma-aminobutyric acid (GABA). Here, mouse splenocytes were found to be viable when supplemented with DREM and fermented DREM containing GABA (fDREM). The addition of DREM and fDREM resulted in the secretion of tumor necrosis factor (TNF)-α from the splenocytes, fDREM being more effective than DREM. The TNF-α secretion with DREM was elevated by exogenous addition of GABA and that with fDREM was in part mediated via A-type GABA receptors. Contrary to general understanding of the suppressive effects of GABA on various biological functions, our findings suggest that GABA-containing fDREM arguments the immune function as a food and pharmaceutical material.
Subject(s)
Chronology as Topic , Fermentation , Phoeniceae/chemistry , Plant Extracts/chemistry , Spleen/cytology , gamma-Aminobutyric Acid/chemistry , Animals , Female , Levilactobacillus brevis/metabolism , Mice , Mice, Inbred BALB C , Spleen/immunology , Tumor Necrosis Factor-alpha/metabolismABSTRACT
Mediterranean Early Iron Age chronology was mainly constructed by means of Greek Protogeometric and Geometric ceramic wares, which are widely used for chronological correlations with the Aegean. However, Greek Early Iron Age chronology that is exclusively based on historical evidence in the eastern Mediterranean as well as in the contexts of Greek colonisation in Sicily has not yet been tested by extended series of radiocarbon dates from well-dated stratified contexts in the Aegean. Due to the high chronological resolution that is only achievable by (metric-scale) stratigraphic 14C-age-depth modelling, the analysis of 21 14C-AMS dates on stratified animal bones from Sindos (northern Greece) shows results that immediately challenge the conventional Greek chronology. Based on pottery-style comparisons with other sites, the new dates for Sindos not only indicate a generally higher Aegean Early Iron Age chronology, but also imply the need for a revised understanding of the Greek periodisation system that will foreseeably have a major impact on our understanding of Greek and Mediterranean history.
Subject(s)
Archaeology/methods , Ceramics/history , Radiometric Dating/methods , Animals , Ceramics/analysis , Chronology as Topic , Fossils/history , Greece , History, Ancient , Humans , SicilyABSTRACT
La phasa (conocida así entre los pobladores aymaras) es un tipo de arcilla comestible que se encuentra en los suelos, empleada como medicina tradicional en la mayoría de los continentes, principalmente para aliviar o tratar patologías gastrointestinales e infecciones cutáneas. Su consumo se remonta muchos siglos atrás; existe evidencia del uso de este elemento en las Placas de arcilla de Nippur en Mesopotamia (2500 años a. C.). Develar las propiedades bio-físico-químicas de las arcillas comestibles está permitiendo a la ciencia explicar las propiedades terapéuticas que posee y así confirmar los grandes avances en la medicina alternativa que tuvieron nuestros antepasados. El uso de la phasa no se limita a la medicina, sino también a muchas otras ramas de la ciencia. En los últimos 10 años se ha experimentado en la agricultura, veterinaria, incluso en el cuidado del medio ambiente dando resultados muy gratificantes y prometedores.
Phasa, an Aymara's language word, is a type of edible clay found in soils; which is used in traditional medicine worldwide mainly to relieve or treat gastrointestinal pathologies and skin infections. Its consumption dates back many centuries, even millennia ago; there is evidence of the use of this element in the clay plates of Nippur in Mesopotamia (2500 years BC). Revealing the bio-physical-chemical properties of edible clay has allowed science to explain their healing and therapeutic properties and confirms the great advances our ancestors got. The use of phasa is not limited to medicine, it is also used in many other sciences; in the last 10 years it has been used in agriculture and veterinary medicine, getting gratifying results.
Subject(s)
Clay , Skin , Soil , Chronology as Topic , InfectionsABSTRACT
The dingo is the only placental land mammal aside from murids and bats to have made the water crossings to reach Australia prior to European arrival. It is thought that they arrived as a commensal animal with people, some time in the mid Holocene. However, the timing of their arrival is still a subject of major debate with published age estimates varying widely. This is largely because the age estimates for dingo arrival are based on archaeological deposit dates and genetic divergence estimates, rather than on the dingo bones themselves. Currently, estimates vary from between 5000-4000 years ago, for finds from archaeological contexts, and as much as 18,000 based on DNA age estimates. The timing of dingo arrival is important as post arrival they transformed Indigenous societies across mainland Australia and have been implicated in the extinction of a number of animals including the Tasmanian tiger. Here we present the results of direct dating of dingo bones from their oldest known archaeological context, Madura Cave on the Nullarbor Plain. These dates demonstrate that dingoes were in southern Australia by between 3348 and 3081 years ago. We suggest that following their introduction the dingo may have spread extremely rapidly throughout mainland Australia.
Subject(s)
Animal Migration , Wolves , Animals , Archaeology , Australia , Caves , Chronology as Topic , Collagen/chemistry , Extinction, Biological , Female , Fossils , History, Ancient , Radiometric Dating , Swimming , Toe PhalangesABSTRACT
Found in 1968, the archaeological site of Anzick, Montana, contains the only known Clovis burial. Here, the partial remains of a male infant, Anzick-1, were found in association with a Clovis assemblage of over 100 lithic and osseous artifacts-all red-stained with ochre. The incomplete, unstained cranium of an unassociated, geologically younger individual, Anzick-2, was also recovered. Previous chronometric work has shown an age difference between Anzick-1 and the Clovis assemblage (represented by dates from two antler rod samples). This discrepancy has led to much speculation, with some discounting Anzick-1 as Clovis. To resolve this issue, we present the results of a comprehensive radiocarbon dating program that utilized different pretreatment methods on osseous material from the site. Through this comparative approach, we obtained a robust chronometric dataset that suggests that Anzick-1 is temporally coeval with the dated antler rods. This implies that the individual is indeed temporally associated with the Clovis assemblage.
Subject(s)
Anthropology, Cultural , Databases, Factual , Indians, North American , Chronology as Topic , Female , History, Ancient , Humans , Male , MontanaABSTRACT
The timing and location of the emergence of our species and of associated behavioural changes are crucial for our understanding of human evolution. The earliest fossil attributed to a modern form of Homo sapiens comes from eastern Africa and is approximately 195 thousand years old, therefore the emergence of modern human biology is commonly placed at around 200 thousand years ago. The earliest Middle Stone Age assemblages come from eastern and southern Africa but date much earlier. Here we report the ages, determined by thermoluminescence dating, of fire-heated flint artefacts obtained from new excavations at the Middle Stone Age site of Jebel Irhoud, Morocco, which are directly associated with newly discovered remains of H. sapiens. A weighted average age places these Middle Stone Age artefacts and fossils at 315 ± 34 thousand years ago. Support is obtained through the recalculated uranium series with electron spin resonance date of 286 ± 32 thousand years ago for a tooth from the Irhoud 3 hominin mandible. These ages are also consistent with the faunal and microfaunal assemblages and almost double the previous age estimates for the lower part of the deposits. The north African site of Jebel Irhoud contains one of the earliest directly dated Middle Stone Age assemblages, and its associated human remains are the oldest reported for H. sapiens. The emergence of our species and of the Middle Stone Age appear to be close in time, and these data suggest a larger scale, potentially pan-African, origin for both.
Subject(s)
Archaeology/methods , Chronology as Topic , Fossils , Hominidae , Phylogeny , Africa/ethnology , Animals , Electron Spin Resonance Spectroscopy , History, Ancient , Hominidae/classification , Humans , Mandible , Morocco , Tooth , Uranium/analysisABSTRACT
There are two models for the origins and timing of the Bronze Age in Southeast Asia. The first centres on the sites of Ban Chiang and Non Nok Tha in Northeast Thailand. It places the first evidence for bronze technology in about 2000 B.C., and identifies the origin by means of direct contact with specialists of the Seima Turbino metallurgical tradition of Central Eurasia. The second is based on the site of Ban Non Wat, 280 km southwest of Ban Chiang, where extensive radiocarbon dating places the transition into the Bronze Age in the 11th century B.C. with likely origins in a southward expansion of technological expertise rooted in the early states of the Yellow and Yangtze valleys, China. We have redated Ban Chiang and Non Nok Tha, as well as the sites of Ban Na Di and Ban Lum Khao, and here present 105 radiocarbon determinations that strongly support the latter model. The statistical analysis of the results using a Bayesian approach allows us to examine the data at a regional level, elucidate the timing of arrival of copper base technology in Southeast Asia and consider its social impact.
Subject(s)
Copper/history , Metallurgy/history , Asia , Bayes Theorem , Bone and Bones/chemistry , Carbon Radioisotopes/analysis , Chronology as Topic , Fossils , History, Ancient , Humans , ThailandABSTRACT
For a long time, anthropological and genetic research on the Neolithic revolution in Europe was mainly concentrated on the mechanism of agricultural dispersal over different parts of the continent. Recently, attention has shifted towards population processes that occurred after the arrival of the first farmers, transforming the genetically very distinctive early Neolithic Linear Pottery Culture (LBK) and Mesolithic forager populations into present-day Central Europeans. The latest studies indicate that significant changes in this respect took place within the post-Linear Pottery cultures of the Early and Middle Neolithic which were a bridge between the allochthonous LBK and the first indigenous Neolithic culture of north-central Europe--the Funnel Beaker culture (TRB). The paper presents data on mtDNA haplotypes of a Middle Neolithic population dated to 4700/4600-4100/4000 BC belonging to the Brzesc Kujawski Group of the Lengyel culture (BKG) from the Kuyavia region in north-central Poland. BKG communities constituted the border of the "Danubian World" in this part of Europe for approx. seven centuries, neighboring foragers of the North European Plain and the southern Baltic basin. MtDNA haplogroups were determined in 11 individuals, and four mtDNA macrohaplogroups were found (H, U5, T, and HV0). The overall haplogroup pattern did not deviate from other post-Linear Pottery populations from central Europe, although a complete lack of N1a and the presence of U5a are noteworthy. Of greatest importance is the observed link between the BKG and the TRB horizon, confirmed by an independent analysis of the craniometric variation of Mesolithic and Neolithic populations inhabiting central Europe. Estimated phylogenetic pattern suggests significant contribution of the post-Linear BKG communities to the origin of the subsequent Middle Neolithic cultures, such as the TRB.
Subject(s)
Ethnicity/genetics , Genetics, Population , Chronology as Topic , DNA, Mitochondrial , Ethnicity/history , Evolution, Molecular , Gene Frequency , Genotype , Geography , Haplotypes , History, Ancient , Humans , Poland/ethnology , Sequence Analysis, DNAABSTRACT
Exploration of a landlocked cenote on Lifou (Loyalty Islands) revealed 37 shells of the cephalopod Nautilus macromphalus Sowerby, 1849, in saltwater on the cenote floor, approximately 40 m below the water surface. The occurrence of these shells is unusual because N. macromphalus is restricted to the open marine waters surrounding the island. All of the shells are mature, and nearly all of them are unbroken, with faded red-brown color stripes. We analyzed seven shells to determine their age. Radiocarbon dating yielded ages of 6380±30 to 7095±30 y BP. The 238U-series radionuclides 210Pb (half-life â=â22.3 y) and 226Ra (half-life â=â1600 y) also were measured. Two of the samples showed radioactive equilibrium between the nuclides, consistent with the old radiocarbon dates, but the other five samples showed excess 210Pb. When corrected for radioactive decay, the 226Ra activities were much greater than those found in living Nautilus. We conclude that exposure to high activities of 222Rn and 226Ra in the salty groundwater of the cenote altered the activities originally incorporated into the shells. Human placement of the shells in the cavity is rejected based on their radiocarbon age and the geometry of the cenote. The most probable explanation is that the animals entered the flooded karstic system through a connection on the seaward side at approximately 7,000 y BP, during an interval of slowly rising sea level. Unable to find an exit and/or due to anoxic bottom waters, the animals were trapped and died inside. The open connection with the sea persisted for â¼700 y, but after â¼6400 y BP, the connection was lost, probably due to a roof collapse. This is a rare example of Nautilus in a karstic coastal basin and provides a minimum age for the appearance of N. macromphalus in the Loyalty Islands.
Subject(s)
Nautilus/anatomy & histology , Nautilus/physiology , Animal Shells/physiology , Animals , Chronology as Topic , Humans , New Caledonia , Radiometric Dating , Radium/analysis , Uranium/analysisABSTRACT
StW 573, Little Foot, is the most complete Australopithecus skeleton yet discovered, with many of its bones found in their correct anatomical position. Since the discovery of the in situ skeleton in the Silberberg Grotto in 1997, several teams have attempted to date the fossil. This appeared a simple process because several flowstones are inter-bedded in the breccia above and below StW 573. Dating of these flowstones, using U-Pb (uranium-lead) isotope decay techniques, gave younger results than expected from the fauna and stratigraphic position, around 2.2 Ma (millions of years). Our recent stratigraphic, micromorphological and geochemical studies revealed that the stratigraphy is much more complicated than was previously thought, with localized post-depositional processes leading to the creation of voids within the breccia around the skeleton. These voids were then filled by multiple generations of flowstone growth. The research we present here demonstrates that the proposed dates based on the flowstone deposition can give only a minimum age for StW 573 and that the flowstone formation came after, and probably long after, the breccia deposition. If one takes account of the long evolution of these karst fillings, StW 573 appears to be significantly older than 2.2 Ma.
Subject(s)
Chronology as Topic , Fossils , Hominidae , Radiometric Dating , Animals , Archaeology , Biological Evolution , Bone and Bones/chemistry , Geologic Sediments/chemistry , Lead Radioisotopes/chemistry , Paleontology , South Africa , Uranium/chemistryABSTRACT
The discovery and first dates of the paintings in Grotte Chauvet provoked a new debate on the origin and characteristics of the first figurative Palaeolithic art. Since then, other art ensembles in France and Italy (Aldène, Fumane, Arcy-sur-Cure and Castanet) have enlarged our knowledge of graphic activity in the early Upper Palaeolithic. This paper presents a chronological assessment of the Palaeolithic parietal ensemble in Altxerri B (northern Spain). When the study began in 2011, one of our main objectives was to determine the age of this pictorial phase in the cave. Archaeological, geological and stylistic evidence, together with radiometric dates, suggest an Aurignacian chronology for this art. The ensemble in Altxerri B can therefore be added to the small but growing number of sites dated in this period, corroborating the hypothesis of more complex and varied figurative art than had been supposed in the early Upper Palaeolithic.
Subject(s)
Archaeology , Caves , Paintings/history , Chronology as Topic , Geology , History, Ancient , Humans , Radiometric Dating , SpainABSTRACT
Most researchers believe that anatomically modern humans (AMH) first appeared in Africa 160-190 ka ago, and would not have reached eastern Asia until â¼50 ka ago. However, the credibility of these scenarios might have been compromised by a largely inaccurate and compressed chronological framework previously established for hominin fossils found in China. Recently there has been a growing body of evidence indicating the possible presence of AMH in eastern Asia ca. 100 ka ago or even earlier. Here we report high-precision mass spectrometric U-series dating of intercalated flowstone samples from Huanglong Cave, a recently discovered Late Pleistocene hominin site in northern Hubei Province, central China. Systematic excavations there have led to the in situ discovery of seven hominin teeth and dozens of stone and bone artifacts. The U-series dates on localized thin flowstone formations bracket the hominin specimens between 81 and 101 ka, currently the most narrow time span for all AMH beyond 45 ka in China, if the assignment of the hominin teeth to modern Homo sapiens holds. Alternatively this study provides further evidence for the early presence of an AMH morphology in China, through either independent evolution of local archaic populations or their assimilation with incoming AMH. Along with recent dating results for hominin samples from Homo erectus to AMH, a new extended and continuous timeline for Chinese hominin fossils is taking shape, which warrants a reconstruction of human evolution, especially the origins of modern humans in eastern Asia.
Subject(s)
Biological Evolution , Caves/chemistry , Fossils , Geologic Sediments/chemistry , China , Chronology as Topic , Humans , Mass Spectrometry , Radiometric Dating , Tooth/chemistry , Uranium/chemistryABSTRACT
The Sierra de Atapuerca, northern Spain, is known from many prehistoric and palaeontological sites documenting human prehistory in Europe. Three major sites, Gran Dolina, Galería and Sima del Elefante, range in age from the oldest hominin of Western Europe dated to 1.1 to 1.3 Ma (millions of years ago) at Sima del Elefante to c.a. 0.2 Ma on the top of the Galería archaeological sequence. Recently, a chronology based on luminescence methods (Thermoluminescence [TL] and Infrared Stimulated Luminescence [IRSL]) applied to cave sediments was published for the Gran Dolina and Galería sites. The authors proposed for Galería an age of 450 ka (thousands of years ago) for the units lower GIII and GII, suggesting that the human occupation there is younger than the hominid remains of Sima de los Huesos (>530 ka) around 1 km away. In this paper, we present new results obtained by combined Electron Spin Resonance/Uranium-series (ESR/U-series) dating on 20 herbivorous teeth from different levels at the Galería site. They are in agreement with the TL results for the upper part of the stratigraphic sequence (GIV and GIIIb), in the range of between 200 and 250 ka. But for the GIIIa to GIIb levels, the TL ages become abruptly older by 200 ka while ESR ages remain relatively constant. Finally, the TL and ESR data agree in the lowest part of the section (GIIa); both fall in the range of around 350-450 ka. Our results suggest a different interpretation for the GII, GIII and GIV units of Galería and the upper part of Gran Dolina (TD10 and TD11) than obtained by TL. The ESR/U-series results are supported by a Bayesian analysis, which allows a better integration between stratigraphic information and radiometric data.
Subject(s)
Electron Spin Resonance Spectroscopy/methods , Fossils , Luminescent Measurements/methods , Radiometric Dating/methods , Tooth/chemistry , Animals , Bayes Theorem , Chronology as Topic , Geologic Sediments/chemistry , Hominidae , Horses , Ruminants , Spain , Uranium/chemistryABSTRACT
PURPOSE: This study was conducted to examine the effect of baby massage on attachment between mothers and their newborns. METHODS: This study was carried out from June 2008 to February 2010 in a quasi-experimental design (57 in the experimental group, 60 in the control group). Between the dates of the study, all healthy primipara mothers and their healthy babies were included. Data were collected regarding their demographic characteristics and by using the Maternal Attachment Inventory (MAI). All mothers were assessed on the first and the last days of the 38-day study period. In the experimental group, the babies received a 15-minute massage therapy session everyday during the 38 days. RESULTS: There was no significant difference found in the pretest mean value baseline of the MAI score in both groups. The posttest mean values of the MAI of the experimental group mothers (90.87 +/- 10.76) were significantly higher than those of control group (85.10 +/- 15.50). There was a significant difference between groups (p < .05). CONCLUSION: The results of the study have shown that baby massage is effective in increasing the mothere infant attachment.
Subject(s)
Humans , Infant , Chronology as Topic , Complementary Therapies , House Calls , Massage , MothersABSTRACT
BACKGROUND: To study the effects of an aqueous extract of date fruit (Phoenix dactylifera L. Arecaceae) diet on diabetic polyneuropathy (DPN) in streptozotocin- (STZ-) induced diabetic rats. METHODS: The effects of a date fruit extract (DFE) diet on diabetic neuropathy in STZ-induced diabetic rats were evaluated and compared with a nondiabetic control group, diabetic control group (sham), and vehicle group with respect to the following parameters: open field behavioral test, motor nerve conduction velocity (MNCV), and morphological observations. RESULTS: In the model of STZ-induced of diabetic neuropathy, chronic treatment for 6 weeks with DFE counteracted the impairment of the explorative activity of the rats in an open field behavioral test and of the conduction velocity of the sciatic nerve (MNCV). In addition, pretreatment with DFE significantly reversed each nerve diameter reduction in diabetic rats. CONCLUSION: DFE treatment shows efficacy for preventing diabetic deterioration and for improving pathological parameters of diabetic neuropathy in rats, as compared with control groups.
Subject(s)
Chronology as Topic , Diabetes Mellitus, Experimental/complications , Diabetic Neuropathies/drug therapy , Fruit , Motor Neurons/drug effects , Neuroprotective Agents/administration & dosage , Plant Extracts/administration & dosage , Animals , Behavior, Animal/drug effects , Diabetic Neuropathies/physiopathology , Male , Motor Neurons/pathology , Motor Neurons/physiology , Neural Conduction/drug effects , Neuroprotective Agents/adverse effects , Plant Extracts/adverse effects , Rats , Rats, Wistar , Sciatic Nerve/drug effects , Sciatic Nerve/pathology , Sciatic Nerve/physiopathologyABSTRACT
The surface expressions of hydrothermal systems are prime targets for astrobiological exploration, and fossil systems on Earth provide an analogue to guide this endeavor. The Paleozoic Mt. Gee-Mt. Painter system (MGPS) in the Northern Flinders Ranges of South Australia is exceptionally well preserved and displays both a subsurface quartz sinter (boiling horizon) and remnants of aerial sinter pools that lie in near-original position. The energy source for the MGPS is not related to volcanism but to radiogenic heat produced by U-Th-K-rich host rocks. This radiogenic heat source drove hydrothermal circulation over a long period of time (hundreds of millions of years, from Permian to present), with peaks in hydrothermal activity during periods of uplift and high water supply. This process is reflected by ongoing hot spring activity along a nearby fault. The exceptional preservation of the MGPS resulted from the lack of proximal volcanism, coupled with tectonics driven by an oscillating far-field stress that resulted in episodic basement uplift. Hydrothermal activity caused the remobilization of U and rare earth elements (REE) in host rocks into (sub)economic concentrations. Radiogenic-heat-driven systems are attractive analogues for environments that can sustain life over geological times; the MGPS preserves evidence of episodic fluid flow for the past â¼300 million years. During periods of reduced hydrothermal activity (e.g., limited water supply, quiet tectonics), radiolytic H(2) production has the potential to support an ecosystem indefinitely. Remote exploration for deposits similar to those at the MGPS systems can be achieved by combining hyperspectral and gamma-ray spectroscopy.
Subject(s)
Fossils , Hot Springs , Chronology as Topic , Exobiology , Geologic Sediments/analysis , Uranium/analysisABSTRACT
BACKGROUND: Date seeds have been shown to contain high amounts of antioxidants. However, in vivo studies on date seeds are lacking. Therefore the purpose of this study was to determine the effect of date seeds on oxidative damage and antioxidant status in vivo. Male Wistar rats were fed a basal diet containing 0, 70 or 140 g kg(-1) date seeds for 30 days. All three diets were isonitrogenous and isocaloric. Indication of oxidative damage was assessed in the liver and serum, and antioxidant status was assessed in the liver. Serum biochemical parameters, including indicators of tissue cellular damage and complete blood count with differential, were also determined. RESULTS: The results showed that date seeds significantly (P<0.05) reduced liver and serum malondialdehyde (a lipid peroxidative damage product) and serum lactate dehydrogenase and creatine kinase. Liver antioxidants (vitamin E, vitamin C, glutathione, superoxide dismutase, glutathione peroxidase and catalase), complete blood count with differential and other serum biochemical parameters assessed were not significantly altered by date seeds. CONCLUSION: The results obtained suggest a protective effect of date seeds against in vivo oxidative damage, possibly through the action of their bioactive antioxidants.
Subject(s)
Antioxidants/pharmacology , Chronology as Topic , Lipid Peroxidation/drug effects , Liver/drug effects , Oxidative Stress/drug effects , Plant Preparations/pharmacology , Seeds , Animals , Antioxidants/metabolism , Creatine Kinase/blood , Diet , L-Lactate Dehydrogenase/blood , Liver/metabolism , Male , Malondialdehyde/blood , Malondialdehyde/metabolism , Rats , Rats, WistarABSTRACT
Palaeomagnetic analysis was conducted on speleothems from Members 1-5 at Sterkfontein Cave, South Africa. Palaeomagnetic analysis of siltstone and speleothem from the bulk of Member 4 indicate a reversed magnetic polarity that dates the deposits and its Australopithecus africanus fossils to between 2.58 and ~2.16 Ma. Further confirmation of this age comes in the form of two short normal polarity events correlated to the Rèunion (~2.16 Ma) and Huckleberry Ridge (~2.05 Ma) events in speleothem capping the bulk of Member 4 and coeval with deposition of the final phase of Member 4, including A. africanus fossil Sts 5. At ~2.16-2.05 Ma, Sts 5 is the youngest representative of A. africanus yet discovered. Palaeomagnetic analysis of the Silberberg Grotto deposits identifies a single short geomagnetic field event in flowstone overlying the StW 573 Australopithecus fossil, which is suggested to represent the Rèunion event at ~2.16 Ma. This further supports the uranium lead age estimates of 2.3-2.2 Ma for the StW 573 fossil. Based on a reversed polarity for the deposits below the skeleton it cannot be older than 2.58 Ma. If StW 573 is considered to be a second species of Australopithecus then this indicates that two species of Australopithecus are present at Sterkfontein between 2.6 and 2.0 Ma. All of the Member 5 deposits date to less than 1.8 Ma based on a comparison of palaeomagnetic, faunal, and electron spin resonance age estimates. The StW 53 fossil bearing infill (M5A) is intermediate in age between Member 4 and the rest of Member 5 (B-C) at around 1.78-1.49 Ma. The rest of Member 5 (B-C) containing Oldowan and Acheulian stone tools and Homo and Paranthropus fossils was deposited gradually between 1.40 and 1.07 Ma, much younger than previously suggested.