Search results for "ISOTOPES"
showing 10 items of 1216 documents
Mobility or migration: a case study from the Neolithic settlement of Nieder-Mörlen (Hessen, Germany)
2009
A combination of stable carbon and nitrogen isotope analysis of collagen and radiogenic strontium isotope analysis of tooth enamel was used to investigate diet and mobility at the early Neolithic settlement of Nieder-Morlen in Germany. The carbon and nitrogen ratios suggest a mixed terrestrial based diet that is consistent with data previously published for early Neolithic sites in Europe. The strontium isotope data indicate a high degree of human mobility with only one individual having an isotope ratio consistent with locally derived strontium. Unusually, a group of non-local juveniles with isotope ratios typical of upland regions is also present at the settlement but there are no adult b…
From pedologic indications to archaeological reconstruction: deciphering land use in the Islamic period in the Baida district (north-western Sicily)
2013
Abstract The aim of this work was to detect imprints on soil properties from former Islamic land use (9th to 11th century) using a multi-method, soil-chemical approach. Four soil profiles (with buried horizons) found in the vicinities of former Islamic settlements in Sicily were analysed for phosphorus (total, organic and inorganic), nitrogen (total, NO 3 − and NH 4 + ), carbon compounds (δ 13 C, lipids, polycyclic aromatic hydrocarbons (PAH) and functional groups), physical and chemical C-fractions and the state of soil weathering. Two soil profiles contained ceramic sherds from the Islamic period. Inorganic nitrogen forms, phosphorous and the PAH content indicated strong impacts from trad…
Activation of nitric oxide signaling by the rheumatoid arthritis shared epitope
2006
Objective. Susceptibility to rheumatoid arthritis (RA) is closely associated with HLA–DRB1 alleles encoding a shared epitope (SE) in positions 70–74 of the HLA–DR chain. The mechanistic basis for this association is unknown. Given the proposed pathogenic role of nitric oxide (NO) in RA, this study was undertaken to examine whether the SE can trigger NO signaling events. Methods. The intracellular levels of NO were measured with the fluorescent NO probe 4,5diaminofluorescein diacetate and by the 2,3diaminonaphthalene method. NO synthase activity was determined by measuring the rate of conversion of radioactive arginine to citrulline. Levels of cGMP were measured with a commercial enzyme-link…
Access to Gamma-ray Spectroscopy of Neutron-Rich sdfp Shell Nuclei
2000
γ-rays in neutron-rich sdfp shell nuclei, produced in deep-inelastic processes during collisions of 37Cl and 40Ar ions on 208Pb and of 48Ca ions on 48Ca, have been studied using large Ge multidetector arrays. Candidates for new yrast states in heavy argon and sulfur isotopes have been identified.
Dental calculus is not equivalent to bone collagen for isotope analysis: a comparison between carbon and nitrogen stable isotope analysis of bulk den…
2014
Palaeodietary reconstruction using the carbon and nitrogen isotope values of bone and dentine collagen is a well-established method and the biochemical processes involved are well known. Researchers have recently explored using bulk samples of dental calculus as a substitute for bone and dentine collagen in dietary analyses, because calculus can be sampled without causing damage to the teeth, and may be useful in situations where more destructive analyses are not possible, or where collagen is poorly preserved. Several questions remain about the use of bulk calculus as a source of carbon and nitrogen isotope data, however. It is not yet clear how much of an individual¿s life span dental cal…
JAK3/STAT5/6 Pathway Alterations Are Associated with Immune Deviation in CD8+ T Cells in Renal Cell Carcinoma Patients
2010
To investigate the molecular mechanisms underlying altered T cell response in renal cell carcinoma (RCC) patients, we compared autologous and allogeneic CD8(+) T cell responses against RCC line from RCC patients and their HLA-matched donors, using mixed lymphocyte/tumor cell cultures (MLTCs). In addition, we analyzed the expression of molecules associated with cell cycle regulation. Autologous MLTC responder CD8(+) T cells showed cytotoxic activity against RCC cell lines; however the analysis of the distribution of CD8(+) T-cell subsets revealed that allogenic counterparts mediate superior antitumor efficacy. In RCC patients, a decreased proliferative response to tumor, associated with defe…
Climate signals in carbon and oxygen isotope ratios of Pinus cembra tree‐ring cellulose from the Călimani Mountains, Romania
2020
Abstract We analyze annually resolved tree-ring stable carbon (I´13C) and oxygen (I´18O) isotopic chronologies from Swiss stone pine (Pinus cembra L.) in Romania. The chronologies cover the period between 1876 and 2012 and integrate data from four individual trees from the Calimani Mts in the eastern Carpathians where climatic records are scarce and starts only from 1961. Calibration trials show that the I´13C values correlate with local April-May relative humidity and with regional to larger scale (European) summer precipitation. I´18O correlates significantly with local relative humidity, cloud cover, maximum temperature, as well as European scale drought conditions. In all cases, the cli…
δ13C variations in tree rings as an indication of severe changes in the urban air quality
2002
Abstract Annual growth rings sampled from three free-standing trees (Platanus hybrida sp.), grew in the metropolitan area of Palermo (Italy) and covering a 118 years time span (1880–1998), have been studied for their 13C/12C carbon isotope ratios. It has been found that the 13C/12C tree ring record, during the study time interval, decreased of −3.6‰, from −26.4‰ in 1880 to −30‰ in 1998. Such a progressive depletion has been attributed to the addition of anthropogenic 13C depleted carbon dioxide to the local atmosphere. The observed 13C/12C decrease has been used to infer some possible pathways of atmospheric CO2 change in the study urban area.
Paleoceanography of the Late Cretaceous northwestern Tethys Ocean: Seasonal upwelling or steady thermocline?
2020
In this study we attempted to assess whether seasonal upwelling or a steady thermocline persisted at the western margin of the Tethys Ocean during the late Turonian-early Coniacian interval. For this scope, we employed novel and published stable oxygen isotope (δ18O) data of various organisms (bivalves, bivalves, brachiopods, fish and belemnites). New seasonally resolved temperature estimates were based on the δ18O record of sequentially sampled inoceramid (Inoceramus sp.) and rudist (Hippurites resectus) shells from the Scaglia Rossa and Gosau deposits of northern Italy and western Austria, respectively. Diagenetic screening was performed using reflected light, cathodoluminescence (CL), sc…
RADIONUCLIDE CONCENTRATIONS IN AIR PARTICULATE AT PALERMO (ITALY) FOLLOWING FUKUSHIMA ACCIDENT
2012
Following the Fukushima accident, a series of samplings were carried out with a daily frequency to detect the arrival of radioactive contamination in air at Palermo (Italy) and to follow its evolution during the time. Air particulate collection was performed by suction of atmospheric air through cellulose filter paper by means of a high-volume air sampler (∼15 000 m(3) d(-1)). Spectrometric analysis of the filters highlights the presence of (131)I, (134)Cs, (137)Cs and, only for a few samples, traces of (132)Te-(132)I and (136)Cs. Maximum airborne concentrations were 883 μBq m(-3) for (131)I (only particulate), 81 μBq m(-3) for (137)Cs and 70 μBq m(-3) for (134)Cs. From a dose to population…