Search results for "Cave"
showing 10 items of 606 documents
Betanin inhibits the myeloperoxidase/nitrite-induced oxidation of human low-density lipoproteins
2007
Production of nitrogen dioxide by the activity of myeloperoxidase (MPO) in the presence of nitrite is now considered a key step in the pathophysiology of low-density lipoprotein (LDL) oxidation. This study shows that betanin, a phytochemical of the betalain class, inhibits the production of lipid hydroperoxides in human LDL submitted to a MPO/nitrite-induced oxidation. Kinetic measurements including time-course of particle oxidation and betanin consumption, either in the presence or in the absence of nitrite, suggest that the antioxidant effect is possibly the result of various actions. Betanin scavenges the initiator radical nitrogen dioxide and can also act as a lipoperoxyl radical-scaven…
Reactive oxygen species (ROS) generation inhibited by aporphine and phenanthrene alkaloids semi-synthesized from natural boldine.
2004
Four phenanthrene and one aporphine alkaloids semi-synthesized from boldine were evaluated for their inhibitory effect on reactive oxygen species (ROS) generation. ROS generation by neutrophils stimulated with N-formyl-methionyl-leucyl-phenylalanine was inhibited in a concentration dependent manner. Alkaloids exerted similar inhibitory effect in the hypoxanthine-xanthine oxidase system than in stimulated neutrophils, which could be attributed to a direct ROS scavenging activity. None of the alkaloids assayed had any effect on xanthine oxidase activity. Therefore the synthesized alkaloids might constitute an alternative therapy in inflammation disorders in which ROS generation is involved.
Nonlinear nonhomogeneous Neumann eigenvalue problems
2015
We consider a nonlinear parametric Neumann problem driven by a nonhomogeneous differential operator with a reaction which is $(p-1)$-superlinear near $\pm\infty$ and exhibits concave terms near zero. We show that for all small values of the parameter, the problem has at least five solutions, four of constant sign and the fifth nodal. We also show the existence of extremal constant sign solutions.
Last Glacial Human Settlement in Eastern Cantabria (Northern Spain)
2002
While the excavation of individual sites remains fundamental to the creation of the Palaeolithic archeological record, increasingly the focus of prehistoric research is on human adaptations to and within natural regions. Such a reorientation implies viewing sites and occupations as samples of different suites of activities in various habitats across space and time; it is dependent on the use of radiocarbon to date and relate occupation residues among sites; and it necessitates the application of methods to uncover patterns of human mobility as an integral aspect of subsistence economy, demographic arrangements and social relations. This paper contributes to the regional study of Last Glacia…
Holocene climate variability in Central Germany and a potential link to the polar North Atlantic: A replicated record from three coeval speleothems
2016
Here, we present high-resolution trace element and stable isotope records from three coeval Holocene stalagmites from the Herbstlabyrinth cave system, Central Germany. All stalagmites were precisely dated using MC-ICPMS 230Th/U-dating. One stalagmite started to grow at 13.62 ± 0.13 ka BP, covering the late Glacial; the other two speleothems started to grow at 11.13 ± 0.08 and 10.26 ± 0.08 ka BP, respectively. The combined record covers the entire Holocene. The interpretation of the different climate proxies is supported by data from a detailed cave monitoring programme. Cold conditions during the Younger Dryas are reflected by intermittent stalagmite growth at the Herbstlabyrinth. The δ18O…
Fauna e industria en materia dura de origen animal del lugar sagrado de la Cultura de las Motillas: Castillejo del Bonete (Terrinches, Ciudad Real)
2020
En los últimos años revistas científicas han publicado diversos estudios (cerámica, metal, material lítico, etc.) sobre Castillejo del Bonete. Este trabajo presenta datos inéditos sobre la industria ósea, micro y macromamíferos encontrados en este yacimiento. La industria elaborada sobre materia dura de origen animal está constituida principalmente por piezas elaboradas con hueso, asta o dientes, que fueron utilizados como medios de producción o complementos para vestir y adornar a los difuntos, o tallar ídolos. El estudio de los micromamíferos aporta información sobre el final del uso de estos túmulos, así como sobre aspectos ambientales. Los perfiles de mortalidad de los grandes mamíferos…
Increasing contextual information by merging existing archaeological data with state of the art laser scanning in the prehistoric funerary deposit of…
2013
Abstract In this paper we present a virtual reconstruction of prehistoric funerary practices in Pastora Cave, a collective burial site in Eastern Spain that dates from the Late Neolithic, Chalcolithic and Bronze Age. Modern data of the cave was captured by 3D laser scanning techniques and added to recorded archaeological data and 3D graphic information. The combination of these data sets allowed us to create a hypothetical reconstruction to analyze the material excavated in the 1940s and 50s in greater spatial context. A 3D model of the current cave was created in order to serve as a basis for modeling the relative stratigraphic information available. We present the methodology employed and…
A laboratory cave for the study of wall degradation in rock art caves : an implementation in the Vézère area
2013
The aim of this proposal is to present an original approach to the study and preservation of rock art caves. A multidisciplinary study of cave wall alteration will be performed to understand the impact of environmental context on the evolution of wall surfaces. The approach involves the choice of a cave with characteristics similar to painted caves in the studied area (Vézère Valley in Dordogne, France): e.g., cave wall alteration, lithology, morphology, etc. This selected cave is intended to become a laboratory cave, monitored for the acquisition of chemical, physical and biological environmental data on bedrock, air and fluids along with their characteristics. A cave without art or archae…
Osteological and paleodietary investigation of burials from Cova de la Pastora, Alicante, Spain
2011
We present results of osteological and isotopic analyses of human remains from Cova de la Pastora (Alcoi, Alicante, Spain) and discuss the implications in light of a new sequence of radiocarbon dates indicating that the cave was used as a burial site in the Late Neolithic (ca. 3800e3000 cal BC), Chalcolithic (ca. 3000 e2500 cal BC), Bell Beaker Transition (Horizonte Campaniforme Transicional - HCT; ca. 2500e2200 cal BC) and the Bronze Age (ca. 2200e1500 cal BC). Similarities in stable isotopic values of C and N indicate little variation in subsistence between men and women, and a similar nutritional base from the Late Neolithic to the Bronze Age. This pattern of stability is augmented by ev…
First evidence of Pleistocene ochre production from bacteriogenic iron oxides. A case study of the Upper Palaeolithic site at the San Teodoro Cave (S…
2020
Abstract The use of iron pigments is well documented in the archaeological horizons of the different parts of the world since the Middle Pleistocene. The mineralogical and chemical composition of the pigments allowed defining, in most cases, their inorganic origin, which were then used after a limited transformation and manipulation. The use of a biogenic ochraceous pigment and its manipulation has recently been described in a late Holocene archaeological horizon of the American continent. Here we describe the earliest case of archaeological use of ferrous pigment produced by iron-oxidising bacteria (FeOB), the first identified in a European Epigravettian (late Upper Palaeolithic) layer, at…