186 research outputs found
New AMS (14)C dates from the early Upper Paleolithic sequence of Raqefet Cave, Mount Carmel, Israel
Raqefet Cave (35°04'21"N, 32°39'17"W) is situated in the southeastern side of Mount Carmel in Israel (Figure 1) on the left bank of wadi Raqefet (230 m asl), ~50 m above the wadi bed. It is 50 m long with an area of ~500 m2 (Figure 2). Eric Higgs of Cambridge University and Tamar Noy of the Israel Museum conducted excavations at the site between 1970 and 1972 (Higgs et al. 1975). New excavations at the cave began in 2004 (Lengyel et al. 2005)
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30,000 Years Old Wild Flax Fibers - Testimony for Fabricating Prehistoric Linen
A unique finding of wild flax fibers from a series of Upper Paleolithic layers at Dzudzuana Cave, located in the foothills of the Caucasus, Georgia, indicates that prehistoric hunter-gatherers were making cords for hafting stone tools, weaving baskets, or sewing garments. Radiocarbon dates demonstrate that the cave was inhabited intermittently during several periods dated to 32 to 26 thousand years before the present (kyr B.P.), 23 to 19 kyr B.P., and 13 to 11 kyr B.P. Spun, dyed, and knotted flax fibers are common. Apparently, climatic fluctuations recorded in the cave’s deposits did not affect the growth of the plants because a certain level of humidity was sustained.Anthropolog
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Response to Comment by Bergfjord et al.
The comment by Bergfjord et al. expresses doubts concerning the possibility of
identifying flax fibers on the basis of the morphology of their internal layers. The authors use microphotographs and descriptions of the outer layers of fibers as arguments for their claims. Morphology and structure of the outer and inner parts of fibers are radically different, and for that reason the methodological approach of Bergfjord et al. is questionable.Anthropolog
The onset of faba bean farming in the Southern Levant
Even though the faba bean (Vicia faba L.) is among the most ubiquitously cultivated crops, very little is known about its origins. Here, we report discoveries of charred faba beans from three adjacent Neolithic sites in the lower Galilee region, in the southern Levant, that offer new insights into the early history of this species. Biometric measurements, radiocarbon dating and stable carbon isotope analyses of the archaeological remains, supported by experiments on modern material, date the earliest farming of this crop to ~10,200 cal BP. The large quantity of faba beans found in these adjacent sites indicates intensive production of faba beans in the region that can only have been achieved by planting non-dormant seeds. Selection of mutant-non-dormant stock suggests that the domestication of the crop occurred as early as the 11(th) millennium cal BP. Plant domestication| Vicia faba L.| Pre-Pottery Neolithic B| radiocarbon dating| Δ(13)C analysis
Assessing local and long-range structural disorder in aggregate-free lime binders
For aggregate-free, calcite-containing lime binders, we correlate long-range crystallinity parameters from X-ray diffraction measurements (lattice constants, crystalline
domain sizes, and microstrain fluctuation values) with short-range structural parameters from extended X-ray absorption fine structure data (coordination environments,
attenuation factors, and fit stabilities). In doing so, we reveal a correlation between unit cell contraction and a more ideal local calcite structure. Using Fourier transform
infrared spectroscopy and X-ray absorption near edge spectroscopy, we rule out the possibility of contributions from amorphous calcium carbonate, and show that the structural disorder is likely related to localized regions of incomplete carbonation. Thus, by using data from this judicious combination of structural characterization tools, we demonstrate that short-range structural distortions occur in calcitic lime binders, and that these distortions can be detected even in multi-phase mixtures
Evaluation of benzydamine effects on Candida albicans adhesion, biofilm formation and persistence onto abiotic surfaces
Introduction. Candida albicans is the most abundant yeast colonizing the oral cavity. It behaves as an opportunistic pathogen, causing mucosal infections mainly in immunocompromised individuals; in addition, it is often associated to patients suffering from diabetes, oral cancer and terminally ill conditions. Benzydamine hydrochloride is a non-steroidal and anti-inflammatory agent. It has been included in the formulation of several mouthwashes because endowed with analgesic and anesthetic properties. Since benzydamine exerts antibacterial and antifungal activity in vitro, we assessed if this molecule could affect C. albicans virulence traits, such as adhesion, biofilm formation and persistence on abiotic surfaces.
Materials and Methods. C. albicans CA1398, carrying the bioluminescence ACT1p-gLUC59 fusion product, was employed. Firstly, fungal cells were exposed for 1\u2019, 5\u2019, or 15\u2019 to 4 different benzydamine concentrations (0.075%, 0.15%, 0.3% and 0.6%) and then tested for their capacity to adhere to plastic (90\u2019 incubation) or to form a biofilm (24h assay). Secondly, 24 and 48h-old biofilms were exposed to the same concentrations of benzydamine and for the same times in order to assess biofilm persistence and regrowth. Benzydamine effects were quantified by measuring, in parallel, metabolically active fungal cells (bioluminescence assay) and viable cells (Colony Forming Units assay).
Results. Benzydamine impaired ability to adhere to plastic and to form biofilm, in a dose-dependent fashion; such effects could be ascribed to a direct effect of benzydamine on Candida viability only when using the highest dosage. Moreover, benzydamine caused a dose-dependent decrement in the viability of Candida cells embedded in biofilm, no matter whether a 24h- or a 48h-old sessile community was tested.
Discussion and Conclusions. Benzydamine not only impairs C. albicans biofilm formation, profoundly affecting the initial step of fungal cell adhesion to abiotic surfaces, but it is also able to counteract persistence and regrowth of a preformed biofilm. The capacity of benzydamine to affect C. albicans, a fungus responsible of oral diseases in several categories of susceptible subjects, makes this molecule a very interesting tool for both prevention and treatment of oral candidiasis. Studies employing benzydamine-containing mouthwashes will be carried out, in order to assess and compare the anti-Candida effects of different commercial products
Structural differences in archaeologically relevant calcite
We show that two different sources of calcite (geogenic flowstones and anthropogenic lime plaster) have complex, yet distinctive, structural disorder signatures. It is effective to identify these differences by pairing a rapid, fieldwork-compatible technique (Fourier transform infrared (FTIR) spectroscopy) with a robust laboratory-based technique (X-ray diffraction (XRD) peak width analyses). We demonstrate that crystalline domain size, microstrain fluctuations, and lattice strain each affect the FTIR spectra of calcite. To focus on each variable separately, XRD data and FTIR absorption spectra are compared among calcite samples formed by different processes. Small crystalline domain sizes cause changes to FTIR peak intensity ratios (grinding curves). However, larger microstrain fluctuations or larger lattice strain also produce similar changes. Thus, inferring structural differences from calcite FTIR spectra alone is not advisable. Instead, we advocate using FTIR grinding curves in conjunction with analyses of angle-dependent XRD peak widths using the Williamson–Hall relation. Thus, combining these two analysis techniques is more powerful and informative than using either one alone. These findings are relevant for heritage science, including archaeology
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Radiocarbon Dating of Charcoal and Bone Collagen Associated with Early Pottery at Yuchanyan Cave, Hunan Province, China
Yuchanyan Cave in Daoxian County, Hunan Province (People's Republic of China), yielded fragmentary remains of 2 or more ceramic vessels, in addition to large amounts of ash, a rich animal bone assemblage, cobble and flake artifacts, bone tools, and shell tools. The artifacts indicate that the cave was a Late Paleolithic foragers' camp. Here we report on the radiocarbon ages of the sediments based on analyses of charcoal and bone collagen. The best-preserved charcoal and bone samples were identified by prescreening in the field and laboratory. The dates range from around 21,000 to 13,800 cal BP. We show that the age of the ancient pottery ranges between 18,300 and 15,430 cal BP. Charcoal and bone collagen samples located above and below one of the fragments produced dates of around 18,000. These ceramic potsherds therefore provide some of the earliest evidence for pottery making in China.Anthropolog
Early Neolithic wine of Georgia in the South Caucasus
Chemical analyses of ancient organic compounds absorbed into the pottery fabrics from sites in Georgia in the South Caucasus region, dating to the early Neolithic period (ca. 6,000-5,000 BC), provide the earliest biomolecular archaeological evidence for grape wine and viniculture from the Near East, at ca. 6,000-5,800 BC. The chemical findings are corroborated by climatic and environmental reconstruction, together with archaeobotanical evidence, including grape pollen, starch, and epidermal remains associated with a jar of similar type and date. The very large-capacity jars, some of the earliest pottery made in the Near East, probably served as combination fermentation, aging, and serving vessels. They are the most numerous pottery type at many sites comprising the so-called "Shulaveri-Shomutepe Culture" of the Neolithic period, which extends into western Azerbaijan and northern Armenia. The discovery of early sixth millennium BC grape wine in this region is crucial to the later history of wine in Europe and the rest of the world
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