37 research outputs found

    Electronic structure of Co_xTiSe_2 and Cr_xTiSe_2

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    The results of investigations of intercalated compounds Cr_xTiSe_2 and Co_xTiSe_2 by X-ray photoelectron spectroscopy (XPS) and X-ray emission spectroscopy (XES) are presented. The data obtained are compared with theoretical results of spin-polarized band structure calculations. A good agreement between theoretical and experimental data for the electronic structure of the investigated materials has been observed. The interplay between the M3d--Ti3d hybridization (M=Cr, Co) and the magnetic moment at the M site is discussed. A 0.9 eV large splitting of the core Cr2p{3/2} level was observed, which reveals a strong exchange magnetic interaction of 3d-2p electrons of Cr. In the case of a strong localization of the Cr3d electrons (for x<0.25), the broadening of the CrL spectra into the region of the states above the nominal Fermi level was observed and attributed to X-ray re-emission. The measured kinetic properties are in good accordance with spectral investigations and band calculation results.Comment: 14 pages, 11 figures, submitted to Phys.Rev.

    Magnetic properties of Ni2.18Mn0.82Ga Heusler alloys with a coupled magnetostructural transition

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    Polycrystalline Ni2.18Mn0.82Ga Heusler alloys with a coupled magnetostructural transition are studied by differential scanning calorimetry, magnetic and resistivity measurements. Coupling of the magnetic and structural subsystems results in unusual magnetic features of the alloy. These uncommon magnetic properties of Ni2.18Mn0.82Ga are attributed to the first-order structural transition from a tetragonal ferromagnetic to a cubic paramagnetic phase.Comment: 4 pages, 4 figures, revtex

    On-site data cast doubts on the hypothesis of shifting cultivation in the Late Neolithic (c. 4300-2400 cal. BC): Landscape management as an alternative paradigm

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    This article brings together in a comprehensive way, and for the first time, on- and off-site palaeoenvironmental data from the area of the Central European lake dwellings (a UNESCO World Cultural Heritage Site since 2011). The types of data considered are as follows: high-resolution off-site pollen cores, including micro-charcoal counts, and on-site data, including botanical macro- and micro-remains, hand-collected animal bones, remains of microfauna, and data on woodland management (dendrotypology). The period considered is the late Neolithic (c. 4300–2400 cal. BC). For this period, especially for its earlier phases, discussions of land-use patterns are contradictory. Based on off-site data, slash-and-burn – as known from tropical regions – is thought to be the only possible way to cultivate the land. On-site data however show a completely different picture: all indications point to the permanent cultivation of cereals (Triticum spp., Hordeum vulgare), pea (Pisum sativum), flax (Linum usitatissimum) and opium-poppy (Papaver somniferum). Cycles of landscape use are traceable, including coppicing and moving around the landscape with animal herds. Archaeobiological studies further indicate also that hunting and gathering were an important component and that the landscape was manipulated accordingly. Late Neolithic land-use systems also included the use of fire as a tool for opening up the landscape. Here we argue that bringing together all the types of palaeoenvironmental proxies in an integrative way allows us to draw a more comprehensive and reliable picture of the land-use systems in the late Neolithic than had been reconstructed previously largely on the basis of off-site data

    Inhibition of Adhesion of S-fimbriated Escherichia coli to buccal epithelial cells by human milk fat globule membrane components: a novel aspect of protective function of mucins in the non-immunoglobulin fraction

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    We investigated the presence of factors in human milkthat inhibit Invasion of pathogenic bacteria. The efl'ect of human milk fat globule membrane (HMFGM) components on adhesion of cloned S-fimbriated Escherichia coli to human buccal epithelial cells was analyzed. S fimbriae are a common feature of E. coli strains causing sepsis and meningitis in newborns and are bound to epithelia via sialyl-(a-2-3)galactoside structures. Human milk fat globules (HMFG) could be agglutinated by the above-mentioned bacteria. Agglutination could be inhibited by fetuin, human glycophorin, and a 1-acid glycoprotein. In addition, pretreatment of HMFG with Jlibrio cholerae neuraminidase markedly reduced bacterium-induced agglutinations, indicating the involvement of neuraminic acid-containing glycoproteins. In contrast, Iipid droplets of infant formula or artificiallipid emulsions (Intralipid) could not be agglutinated. HMFG were present in stools of breast-fed neonates as shown by indirect immunofluorescence staining with a monoclonal antibody directed against carbohydrate residues present on HMFGM. These HMFG could be agglutinated by bacteria. HMFG inhibited E. coli adhesion to buccal epithelial cells. To further characterize relevant E. coli binding structures, HMFGM components w~re separated by gel chromatography. The mucin fraction showed the most pronounced inhibitory efrect on adhesion of S-fimbriated E. coli to human buccal epithelial cells. Our data soggest that HMFG inhibit bacterial adhesion in the entire intestine and thereby may provide protection against bacterial infection

    S-fimbriae mediated adhesin of Escherichia coli to human buccal epithelial cells is age independent

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    S-fimbriated Escherichia coli, which cause sepsis and meningitis in the newbom, bind to sialic acid-containing glycoprotein structures on the surface of human buccal epithelial cells. The dependence of · this binding on host age was examined. S-fimbriated · E. coli adhered in comparable numbers to cells in newborns, infants, children and adults (23.0 ± 8.6; 23.1 ± 11.5; 24.7 ± 7.9; 28.9 ± 8.8). Thus, the increased susceptibility of neonates to infections caused by S-fimbriated E. coli cannot be explained by enhanced · adhesion to epithelial cellsDie S-Fimbrien vermittelte Adhiision von Escherichia coli an menschliche Mundschleimhautzellen ist altersunabhĂ€ngig. S-Fimbrien tragende Escherichia coli, die Sepsis und Meningitis . im Neugeborenenalter verursachen, binden an sialinsĂ€urehaltige Glycoproteine atif der OberflĂ€che menschlicher Mundschleimhautzellen. Wir untersuchten die AbhĂ€ngigkeit · der Bindung vom Alter des Schleimhautzellenspenders. S-Fimbrien tragende. E. coli banden in vergleichbarer Zahl an Zellen von Neugeborenen, SĂ€uglingen, Ă€lteren · Kindern und Erwachsenen (23,0 ± 8,6; 23,1 ± 11,5; 24,7 ± 7,9; 28,9 ± 8,8). Die vermehrte EmpfĂ€nglichkeit von Neugeborenen fĂŒr Infektionen, die durch S- Fimbrien tragende E. coli verursacht werden, kann nicht mit einer verstĂ€rkten AdhĂ€sion an Mundschleimhautzellen erklĂ€rt wer.den

    Inhibition of adhesion of S-fimbriated Escherichia coli to epithelial cells by meconium feces of breast fed and formula fed newborns - mucins are the major inhibitor component

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    We investigated the ability of meconium, feces from human milk-fed (HMF) newborns, and feces from formula-fed (FF) newborns to inhibit adhesion of S-fimbriated E. coli to human buccal epithelial cells. S-fimbriae are a common property of E.·coli strains causing sepsis and meningitis in neonates. Meconium had the highest content of neuraminic acid and the strongest inhibitory effect on bacterial adhesion. HMF also exerted high inhibitory activity while FF was markedly less active: To achieve inhibitory effects comparable to HMF a sixfold amount of FF was required. Glycoproteins from excretions were separated by gel chromatography. Fractions obtained were analyzed for adhesion-inhibiting activity. In all excretions analyzed, the mucin-containing fraction could be identified as the major inhibitory component. Inhibition was probably mediated by specific interaction of this fraction with S-fimbriae, as shown by binding of isolated fimbriae on Western blots after electrophoretic separation of glycoproteins. In conclusion, our data support the view that the mucin-containing fraction from meconium and human milk exerts antibacterial functions by preventing adhesin-mediated binding of pathogenic bacteria to mucosal epithelia. Key Words: S-fimbriated E. coli-Inhibition of adhesion-Meconium- Feces of human milk-fed newborns-Feces of formula-fed newborns-Mucins

    Inhibition of adhesion of S-fimbriated Escherichia coli to buccal epithelial cells by human milk fat globule membrane components: a novel aspect of the protective function of mucins in the nonimmunoglobulin fraction.

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    We investigated the presence of factors in human milk that inhibit invasion of pathogenic bacteria. The effect of human milk fat globule membrane (HMFGM) components on adhesion of cloned S-fimbriated Escherichia coli to human buccal epithelial cells was analyzed. S fimbriae are a common feature of E. coli strains causing sepsis and meningitis in newborns and are bound to epithelia via sialyl-(alpha-2-3)galactoside structures. Human milk fat globules (HMFG) could be agglutinated by the above-mentioned bacteria. Agglutination could be inhibited by fetuin, human glycophorin, and alpha 1-acid glycoprotein. In addition, pretreatment of HMFG with Vibrio cholerae neuraminidase markedly reduced bacterium-induced agglutinations, indicating the involvement of neuraminic acid-containing glycoproteins. In contrast, lipid droplets of infant formula or artificial lipid emulsions (Intralipid) could not be agglutinated. HMFG were present in stools of breast-fed neonates as shown by indirect immunofluorescence staining with a monoclonal antibody directed against carbohydrate residues present on HMFGM. These HMFG could be agglutinated by bacteria. HMFG inhibited E. coli adhesion to buccal epithelial cells. To further characterize relevant E. coli binding structures, HMFGM components were separated by gel chromatography. The mucin fraction showed the most pronounced inhibitory effect on adhesion of S-fimbriated E. coli to human buccal epithelial cells. Our data suggest that HMFG inhibit bacterial adhesion in the entire intestine and thereby may provide protection against bacterial infection

    Umwelt-, Landschaft- und Besiedlungsgeschichte

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    ZĂŒrich-Parkhaus OpĂ©ra ĂŒbertrifft vergleichbare Fundstellen deutlich an FlĂ€che und Fundmenge und erlaubt dank der ReprĂ€sentativitĂ€t und hohen Datendichte Einblicke in die Gesellschaft, Wirtschaft und Umwelt der damaligen Bevölkerung. Der vorliegende Band prĂ€sentiert die Ergebnisse der naturwissenschaftlichen Analysen – erstmals in der FeuchtbodenarchĂ€ologie unter Einbezug der Chironomiden- und Cladocerenfossilien sowie ausfĂŒhrlicherer Mykologie – und fĂŒhrt die Erkenntnisse der gesamten Auswertung dieser vor allem horgenzeitlichen Fundstelle in einer Synthese zusammen. Die taphonomischen Resultate aller Disziplinen belegen, dass die Ablagerung der Kulturschichten auf dem grössten Teil der GrabungsflĂ€che ganzjĂ€hrig unter Wasser erfolgte. Die archĂ€obiologischen Ergebnisse bestĂ€tigen die eminente wirtschaftliche Bedeutung von Getreide und Rindern, zeigen aber auch, dass die Rolle von Erbsen und Sammelpflanzen bislang unterschĂ€tzt wurde. Pollenuntersuchungen, Dendrotypologie und ArchĂ€obotanik zeichnen ein detailliertes Bild der menschlichen Eingriffe in die Naturlandschaft. So erhöhten die Siedler zu Beginn einer Siedlungsphase die ProduktivitĂ€t ihrer Umgebung durch gezielte Eingriffe. Das Optimum war nach frĂŒhestens 15 bis 20 Jahren erreicht, dann sank die ProduktivitĂ€t und nach etwa 250 Jahren wurde eine neue Region vorbereitet. Vieles deutet darauf hin, dass wirtschaftlich spezialisierte Nebensiedlungen zusammen einen komplexeren Siedlungsverbund bildeten. Die Siedler bedienten sich ĂŒber weite Teile Europas verbreiteter Symbole, nahmen aber viele Entwicklungen der Westschweiz und am Bodensee nicht auf. Die Fundverteilungen und -typologie sowie die Siedlungsstruktur lassen auf verschiedene soziale Einheiten innerhalb von Parkhaus OpĂ©ra schliessen. Diesen dritten und letzten Band zu ZĂŒrich-Parkhaus OpĂ©ra runden ein kritischer RĂŒckblick auf Organisation und Ablauf von Grabung und Auswertung, Empfehlungen fĂŒr kĂŒnftige Grabungen sowie Ausblicke auf weiterfĂŒhrende Forschungsfragen a

    New data about the consumption of fish from the Alsace Region, France

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    International audienceThis study provides an overview of 11 archaeological sites that yielded fish boneremains from the Roman period through medieval to modern contexts. It bringsnew knowledge about the consumption of fish for the Alsace region. Although thenumbers of remains vary greatly, some diachronic comparisons are possible. Themajority of the species represented in the assemblages from the inland sites sampledwere freshwater fishes, together with a few migratory fishes. Most individuals weresmall‐sized fishes, which may explain the type of structure analysed, for instance,latrines. Two wels catfish vertebrae indicate the presence of this species in France.European marine fishes such as cod and flatfish are very rare, and the importationof marine fish began more recently. However, some herring bones found in theRoman and early medieval period make a straightforward interpretation moredifficult
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