JGU-Publikationen

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Now showing 1 - 20 of 2094
  • ItemZeitschriftenaufsatzOpen Access
    The bivalve Glycymeris planicostalis as a high-resolution paleoclimate archive for the Rupelian (Early Oligocene) of central Europe
    (2015) Walliser, Eric Otto; Schöne, Bernd Reinhard; Tütken, Thomas; Zirkel, Jessica; Grimm, Kirsten; Pross, Jörg
    Current global warming is likely to result in a unipolar glaciated world with unpredictable repercussions on atmospheric and oceanic circulation patterns. These changes are expected to affect seasonal extremes and the year-to-year variability of seasonality. To better constrain the mode and tempo of the anticipated changes, climatologists require ultra-high-resolution proxy data of time intervals in the past, e.g., the Oligocene, during which boundary conditions were similar to those predicted for the near future. In the present paper, we assess whether such information can be obtained from shells of the long-lived bivalve mollusk Glycymeris planicostalis from the late Rupelian of the Mainz Basin, Germany. Our results indicate that the studied shells are pristinely preserved and provide an excellent archive for reconstructing changes of sea surface temperature on seasonal to interannual timescales. Shells of G. planicostalis grew uninterruptedly during winter and summer and therefore recorded the full seasonal temperature amplitude that prevailed in the Mainz Basin ~ 30 Ma. Absolute sea surface temperature data were reconstructed from δ18Oshell values assuming a δ18Owater signature that was extrapolated from coeval sirenian tooth enamel. Reconstructed values range between 12.3 and 22.0 °C and agree well with previous estimates based on planktonic foraminifera and shark teeth. However, temperatures during seasonal extremes vary greatly on interannual timescales. Mathematically re-sampled (i.e., corrected for uneven number of samples per annual increment) winter and summer temperatures averaged over 40 annual increments of three specimens equal 13.6 ± 0.8 and 17.3 ± 1.2 °C, respectively. Such high-resolution paleoclimate information can be highly relevant for numerical climate studies aiming to predict possible future climates in a unipolar glaciated or, ultimately, polar-ice-free world.
  • ItemZeitschriftenaufsatzOpen Access
    Oxygen and carbon isotope variations in a modern rodent community : implications for palaeoenvironmental reconstructions
    (2012) Gehler, Alexander; Tütken, Thomas; Pack, Andreas
    Background: The oxygen (d18O) and carbon (d13C) isotope compositions of bioapatite from skeletal remains of fossil mammals are well-established proxies for the reconstruction of palaeoenvironmental and palaeoclimatic conditions. Stable isotope studies of modern analogues are an important prerequisite for such reconstructions from fossil mammal remains. While numerous studies have investigated modern large- and medium-sized mammals, comparable studies are rare for small mammals. Due to their high abundance in terrestrial ecosystems, short life spans and small habitat size, small mammals are good recorders of local environments. Methodology/Findings: The d18O and d13C values of teeth and bones of seven sympatric modern rodent species collected from owl pellets at a single locality were measured, and the inter-specific, intra-specific and intra-individual variations were evaluated. Minimum sample sizes to obtain reproducible population d18O means within one standard deviation were determined. These parameters are comparable to existing data from large mammals. Additionally, the fractionation between coexisting carbonate (d18OCO3) and phosphate (d18OPO4) in rodent bioapatite was determined, and d18O values were compared to existing calibration equations between the d18O of rodent bioapatite and local surface water (d18OLW). Specific calibration equations between d18OPO4 and d18OLW may be applicable on a taxonomic level higher than the species. However, a significant bias can occur when bone-based equations are applied to tooth-data and vice versa, which is due to differences in skeletal tissue formation times. d13C values reflect the rodents’ diet and agree well with field observations of their nutritional behaviour. Conclusions/Significance: Rodents have a high potential for the reconstruction of palaeoenvironmental conditions by means of bioapatite d18O and d13C analysis. No significant disadvantages compared to larger mammals were observed. However, for refined palaeoenvironmental reconstructions a better understanding of stable isotope signatures in modern analogous communities and potential biases due to seasonality effects, population dynamics and tissue formation rates is necessary.
  • ItemZeitschriftenaufsatzOpen Access
    Opportunistic feeding strategy for the earliest Old World hypsodont equids : evidence from stable isotope and dental wear proxies
    (2013) Tütken, Thomas; Kaiser, Thomas M.; Vennemann, Torsten; Merceron, Gildas
    Background: The equid Hippotherium primigenium, with moderately hypsodont cheek teeth, rapidly dispersed through Eurasia in the early late Miocene. This dispersal of hipparions into the Old World represents a major faunal event during the Neogene. The reasons for this fast dispersal of H. primigenium within Europe are still unclear. Based on its hypsodonty, a high specialization in grazing is assumed although the feeding ecology of the earliest European hipparionines within a pure C3 plant ecosystem remains to be investigated. Methodology/Principal Findings: A multi-proxy approach, combining carbon and oxygen isotopes from enamel as well as dental meso- and microwear analyses of cheek teeth, was used to characterize the diet of the earliest European H. primigenium populations from four early Late Miocene localities in Germany (Eppelsheim, Ho¨wenegg), Switzerland (Charmoille), and France (Soblay). Enamel d13C values indicate a pure C3 plant diet with small (,1.4%) seasonal variations for all four H. primigenium populations. Dental wear and carbon isotope compositions are compatible with dietary differences. Except for the Ho¨wenegg hipparionines, dental microwear data indicate a browse-dominated diet. By contrast, the tooth mesowear patterns of all populations range from low to high abrasion suggesting a wide spectrum of food resources. Conclusions/Significance: Combined dental wear and stable isotope analysis enables refined palaeodietary reconstructions in C3 ecosystems. Different H. primigenium populations in Europe had a large spectrum of feeding habits with a high browsing component. The combination of specialized phenotypes such as hypsodont cheek teeth with a wide spectrum of diet illustrates a new example of the Liem’s paradox. This dietary flexibility associated with the capability to exploit abrasive food such as grasses probably contributed to the rapid dispersal of hipparionines from North America into Eurasia and the fast replacement of the brachydont equid Anchitherium by the hypsodont H. primigenium in Europe.
  • ItemZeitschriftenaufsatzOpen Access
    Tooth oxygen isotopes reveal Late Bronze Age origin of Mediterranean fish aquaculture and trade
    (2018) Sisma-Ventura, Guy; Tütken, Thomas; Zohar, Irit; Pack, Andreas; Sivan, Dorit; Lernau, Omri; Gilboa, Ayelet; Bar-Oz, Guy
    Past fish provenance, exploitation and trade patterns were studied by analyzing phosphate oxygen isotope compositions (δ18OPO4) of gilthead seabream (Sparus aurata) tooth enameloid from archaeological sites across the southern Levant, spanning the entire Holocene. We report the earliest evidence for extensive fish exploitation from the hypersaline Bardawil lagoon on Egypt’s northern Sinai coast, as indicated by distinctively high δ18OPO4 values, which became abundant in the southern Levant, both along the coast and further inland, at least from the Late Bronze Age (3,550–3,200 BP). A period of global, postglacial sea-level stabilization triggered the formation of the Bardawil lagoon, which was intensively exploited and supported a widespread fish trade. This represents the earliest roots of marine proto-aquaculture in Late Holocene coastal domains of the Mediterranean. We demonstrate the potential of large-scale δ18OPO4 analysis of fish teeth to reveal cultural phenomena in antiquity, providing unprecedented insights into past trade patterns.
  • ItemZeitschriftenaufsatzOpen Access
    Past aquatic environments in the Levant inferred from stable isotope compositions of carbonate and phosphate in fish teeth
    (2019) Sisma-Ventura, Guy; Tütken, Thomas; Peters, Stefan T. M.; Bialik, Or M.; Zohar, Irit; Pack, Andreas
    Here we explore the carbon and oxygen isotope compositions of the co-existing carbonate and phosphate fractions of fish tooth enameloid as a tool to reconstruct past aquatic fish environments and harvesting grounds. The enameloid oxygen isotope compositions of the phosphate fraction (δ18OPO4) vary by as much as ~4‰ for migratory marine fish such as gilthead seabream (Sparus aurata), predominantly reflecting the different saline habitats it occupies during its life cycle. The offset in enameloid Δ18OCO3-PO4 values of modern marine Sparidae and freshwater Cyprinidae from the Southeast Mediterranean region vary between 8.1 and 11.0‰, similar to values reported for modern sharks. The mean δ13C of modern adult S. aurata and Cyprinus carpio teeth of 0.1±0.4‰ and -6.1±0.7‰, respectively, mainly reflect the difference in δ13C of dissolved inorganic carbon (DIC) of the ambient water and dietary carbon sources. The enameloid Δ18OCO3-PO4 and δ13C values of ancient S. aurata (Holocene) and fossil Luciobarbus sp. (Cyprinidae; mid Pleistocene) teeth agree well with those of modern specimens, implying little diagenetic alteration of these tooth samples. Paired δ18OPO4-δ13C data from ancient S. aurata teeth indicate that hypersaline water bodies formed in the Levant region during the Late Holocene from typical Mediterranean coastal water with high evaporation rates and limited carbon input from terrestrial sources. Sparid tooth stable isotopes further suggest that coastal lagoons in the Eastern Mediterranean had already formed by the Early Holocene and were influenced by terrestrial carbon sources. Overall, combined enameloid oxygen and carbon isotope analysis of fish teeth is a powerful tool to infer the hydrologic evolution of aquatic environments and assess past fishing grounds of human populations in antiquity.
  • ItemZeitschriftenaufsatzOpen Access
    Forage silica and water content control dental surface texture in guinea pigs and provide implications for dietary reconstruction
    (2019) Winkler, Daniela E.; Schulz-Kornas, Ellen; Kaiser, Thomas M.; De Cuyper, Annelies; Clauss, Marcus; Tütken, Thomas
    Recent studies have shown that phytoliths are softer than dental enamel but still act as abrasive agents. Thus, phytolith content should be reflected in dental wear. Because native phytoliths show lower indentation hardness than phytoliths extracted by dry ashing, we propose that the hydration state of plant tissue will also affect dental abrasion. To assess this, we performed a controlled feeding experiment with 36 adult guinea pigs, fed exclusively with three different natural forages: lucerne, timothy grass, and bamboo with distinct phytolith/silica contents (lucerne < grass < bamboo). Each forage was fed in fresh or dried state for 3 weeks. We then performed 3D surface texture analysis (3DST) on the upper fourth premolar. Generally, enamel surface roughness increased with higher forage phytolith/silica content. Additionally, fresh and dry grass feeders displayed differences in wear patterns, with those of fresh grass feeders being similar to fresh and dry lucerne (phytolith-poor) feeders, supporting previous reports that “fresh grass grazers” show less abrasion than unspecialized grazers. Our results demonstrate that not only phytolith content but also properties such as water content can significantly affect plant abrasiveness, even to such an extent that wear patterns characteristic for dietary traits (browser–grazer differences) become indistinguishable.
  • ItemZeitschriftenaufsatzOpen Access
  • ItemZeitschriftenaufsatzOpen Access
    A bifunctional iron-nickel oxygen reduction/oxygen evolution catalyst for high-performance rechargeable zinc-air batteries
    (2025) Chen, Zhengfan; Cheng, Weiyi; Cao, Kecheng; Jin, Meng; Rahali, Sarra; Chala, Soressa Abera; Ebrahimi, Elnaz; Ma, Nana; Liu, Rongji; Lakshmanan, Keseven; Chang, Chia-Yu; Cheung, Chun-Chi; Luo, Haojian; Wang, Yongkang; Hwang, Bing Joe; Streb, Carsten
    Efficient and robust electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are crucial for fuel cells, metal-air batteries, and other energy technologies. Here, a highly stable, efficient bifunctional OER/ORR electrocatalyst (FeNi-NC@MWCNTs) is reported and demonstrated its integration and robust performance in an aqueous Zinc–air battery (ZAB). The catalyst is based on neighboring iron/nickel sites (FeNiN6) which are atomically dispersed on porous nitrogen-doped carbon particles. The particles are wrapped in electrically conductive multi-walled carbon nanotubes for enhanced electrical conductivity. Electrocatalytic analyses show high OER and ORR performance (OER/ORR voltage difference = 0.69 V). Catalyst integration in a ZAB results in excellent performance metrics, including an open circuit voltage of 1.44 V, a specific capacity of 782 mAh g−1 (at j = 15 mA cm−2), a peak power density of 218 mW cm−2 (at j = 260 mA cm−2) and long-term durability over 600 charge/discharge cycles. Combined experimental and theoretical (density functional theory) analyses provide an in-depth understanding of the physical and electronic structure of the catalyst and the role of the FeNi dual atom reaction site. The study therefore provides critical insights into the structure and reactivity of high-performance bifunctional OER/ORR catalysts based on atomically dispersed non-critical metals.
  • ItemZeitschriftenaufsatzOpen Access
    Dietary and homeostatic controls of Zn isotopes in rats : a controlled feeding experiment and modeling approach
    (2024) Bourgon, Nicolas; Tacail, Théo; Jaouen, Klervia; Leichliter, Jennifer N.; McCormack, Jeremy; Winkler, Daniela E.; Clauss, Marcus; Tütken, Thomas
    The stable isotope composition of zinc (δ66Zn), which is an essential trace metal for many biological processes in vertebrates, is increasingly used in ecological, archeological, and paleontological studies to assess diet and trophic level discrimination among vertebrates. However, the limited understanding of dietary controls and isotopic fractionation processes on Zn isotope variability in animal tissues and biofluids limits precise dietary reconstructions. The current study systematically investigates the dietary effects on Zn isotope composition in consumers using a combined controlled feeding experiment and box-modeling approach. For this purpose, 21 rats were fed one of seven distinct animal- and plant-based diets and a total of 148 samples including soft and hard tissue, biofluid, and excreta samples of these individuals were measured for δ66Zn. Relatively constant Zn isotope fractionation is observed across the different dietary groups for each tissue type, implying that diet is the main factor controlling consumer tissue δ66Zn values, independent of diet composition. Furthermore, a systematic δ66Zn diet-enamel fractionation is reported for the first time, enabling diet reconstruction based on δ66Zn values from tooth enamel. In addition, we investigated the dynamics of Zn isotope variability in the body using a box-modeling approach, providing a model of Zn isotope homeostasis and inferring residence times, while also further supporting the hypothesis that δ66Zn values of vertebrate tissues are primarily determined by that of the diet. Altogether this provides a solid foundation for refined (paleo)dietary reconstruction using Zn isotopes of vertebrate tissues.
  • ItemZeitschriftenaufsatzOpen Access
    Phosphate uptake is an essential process for rapid bone mineralization during early diagenesis : evidence from bone alteration experiments
    (2024) Kral, Anna G.; Geisler, Thorsten; Wiedenbeck, Michael; Guagliardo, Paul; Tütken, Thomas
  • ItemZeitschriftenaufsatzOpen Access
    Spatial ecology of moose in Sweden : combined Sr-O-C isotope analyses of bone and antler
    (2024) Armaroli, Elena; Lugli, Federico; Cipriani, Anna; Tütken, Thomas
    The study of spatial (paleo)ecology in mammals is critical to understand how animals adapt to and exploit their environment. In this work we analysed the 87Sr/86Sr, δ18O and δ13C isotope composition of 65 moose bone and antler samples from Sweden from wild-shot individuals dated between 1800 and 1994 to study moose mobility and feeding behaviour for (paleo)ecological applications. Sr data were compared with isoscapes of the Scandinavian region, built ad-hoc during this study, to understand how moose utilise the landscape in Northern Europe. The 87Sr/86Sr isoscape was developed using a machine-learning approach with external geo-environmental predictors and literature data. Similarly, a δ18O isoscape, obtained from average annual precipitation δ18O values, was employed to highlight differences in the isotope composition of the local environment vs. bone/antler. Overall, 82% of the moose samples were compatible with the likely local isotope composition (n = 53), suggesting that they were shot not far from their year-round dwelling area. ‘Local’ samples were used to calibrate the two isoscapes, to improve the prediction of provenance for the presumably ‘non-local’ individuals. For the latter (n = 12, of which two are antlers and ten are bones), the probability of geographic origin was estimated using a Bayesian approach by combining the two isoscapes. Interestingly, two of these samples (one antler and one bone) seem to come from areas more than 250 km away from the place where the animals were hunted, indicating a possible remarkable intra-annual mobility. Finally, the δ13C data were compared with the forest cover of Sweden and ultimately used to understand the dietary preference of moose. We interpreted a difference in δ13C values of antlers (13C-enriched) and bones (13C-depleted) as a joint effect of seasonal variations in moose diet and, possibly, physiological stresses during winter-time, i.e., increased consumption of endogenous 13C-depleted lipids.
  • ItemZeitschriftenaufsatzOpen Access
    Zinc isotope composition of enameloid, bone and muscle of gilt-head seabreams (Sparus aurata) raised in pisciculture and their relation to diet
    (2024) McCormack, Jeremy; Jaouen, Klervia; Bourgon, Nicolas; Sisma-Ventura, Guy; Tacail, Théo J. G.; Müller, Wolfgang; Tütken, Thomas
    The isotope ratios of zinc (66Zn/64Zn expressed as δ66Zn), a vital nutrient, increasingly demonstrate trophic discrimination among vertebrates, making δ66Zn a valuable dietary proxy for ecological, archaeological, and palaeontological studies. Given the novelty of the methodology, tissue-diet and tissue-tissue zinc isotope fractionation factors remain poorly understood and have so far only been studied in a few terrestrial mammals. Here, we investigate δ66Zn compositions of enameloid, bone, and white muscle of seven artifcially-fed pisciculture gilt-head seabreams (Sparus aurata) from ofshore Israel, in comparison to the Zn isotope composition of their diet. In addition, we also analysed δ66Zn values in the same tissues of wild-caught S. aurata, bluespotted seabream (Pagrus caeruleostictus) and grey triggerfsh (Balistes capriscus) caught of the coast of Israel. We determine a tissue-diet δ66Zn ofset for Sparus aurata of − 0.04±0.09 ‰ (2SD) for bone, − 0.29±0.06 ‰ (2SD) for enameloid, and − 0.45±0.07 ‰ (2SD) for white muscle. Wild-caught fsh have much higher among-individual δ66Zn variability with values distinct from the pisciculture S. aurata, documenting a much more isotopically heterogeneous diet consumed by the wild individuals. Still, tissue–tissue δ66Zn diferences in wild-caught individuals are close to those observed in the pisciculture ones with progressively lower δ66Zn values in the order bone>enameloid>white muscle. Our results demonstrate predictable tissue-diet and tissue-tissue δ66Zn diferences among fsh hard and soft tissues and can be applied to identify the δ66Zn values of dietary input, thereby informing trophic (palaeo)ecological reconstructions.
  • ItemZeitschriftenaufsatzOpen Access
    Stable isotopes show Homo sapiens dispersed into cold steppes ∼45,000 years ago at Ilsenhohle in Ranis, Germany
    (2024) Pederzani, Sarah; Britton, Kate; Trost, Manuel; Fewlass, Helen; Bourgon, Nicolas; McCormack, Jeremy; Jaouen, Klervia; Dietl, Holger; Döhle, Hans-Jürgen; Kirchner, André; Lauer, Tobias; Le Corre, Mael; McPherron, Shannon P.; Meller, Harald; Mylopotamitaki, Dorothea; Orschiedt, Jörg; Rougier, Hélène; Ruebens, Karen; Schüler, Tim; Sinet-Mathiot, Virginie; Smith, Geoff M.; Talamo, Sahra; Tütken, Thomas; Welker, Frido; Zavala, Elena I.; Weiss, Marcel; Hublin, Jean-Jacques
    The spread of Homo sapiens into new habitats across Eurasia ~45,000 years ago and the concurrent disappearance of Neanderthals represents a critical evolutionary turnover in our species’ history. ‘Transitional’ technocomplexes, such as the Lincombian–Ranisian–Jerzmanowician (LRJ), characterize the European record during this period but their makers and evolutionary significance have long remained unclear. New evidence from Ilsenhöhle in Ranis, Germany, now provides a secure connection of the LRJ to H. sapiens remains dated to ~45,000 years ago, making it one of the earliest forays of our species to central Europe. Using many stable isotope records of climate produced from 16 serially sampled equid teeth spanning ~12,500 years of LRJ and Upper Palaeolithic human occupation at Ranis, we review the ability of early humans to adapt to different climate and habitat conditions. Results show that cold climates prevailed across LRJ occupations, with a temperature decrease culminating in a pronounced cold excursion at ~45,000–43,000 cal bp. Directly dated H. sapiens remains confirm that humans used the site even during this very cold phase. Together with recent evidence from the Initial Upper Palaeolithic, this demonstrates that humans operated in severe cold conditions during many distinct early dispersals into Europe and suggests pronounced adaptability.
  • ItemZeitschriftenaufsatzOpen Access
    "And how did that make you feel?" : repeated symptom queries enhance symptom reports elicited by negative affect
    (2024) Petzke, Tara M.; Elspaß, Lina; Köteles, Ferenc; Van den Bergh, Omer; Witthöft, Michael
    Objective: Negative affect, alexithymia, and other predisposing traits (such as health anxiety) can influence an individual's symptom perception. In this study, we used the affective picture paradigm (APP, Bogaerts et al., 2010) to induce symptoms using affective picture stimuli. We aimed to cross-sectionally test the effect of high vs low-frequency symptom queries and analyze the time course of the APP, including interactions with health anxiety and somatic symptom distress. Methods: Participants (N = 124) completed a modified APP and filled out various questionnaires. In the APP, participants were randomized to either a highly-frequent-query condition (18 symptom checklists) or a lessfrequent-query condition (6 checklists). Data were analyzed using ANOVAs, cross-lagged panel models, moderation models, and multilevel models. Results: Both groups had comparable symptom baseline values, but people in the highly frequent as opposed to less frequent condition reported significantly higher symptom levels once the experiment started (F (1,120) = 14.319, p < .001, η2 = .107). Symptom levels stayed stable over the course of the experiment and were best predicted by symptom levels at earlier timepoints in the experiment (β = 0.43 and β = 0.68, both p < .001). Health anxiety levels significantly predicted symptom levels (F(1,121) = 10.054, p = .002, η2 = .077) and moderated the relation between condition and symptom levels (F(2,121) = 16.253, p < .001, η2 = .212). Conclusion: In terms of the predictive processing model (e.g.,[1]), repeated symptom queries following negative affective cues may activate prior beliefs about symptoms, resulting in elevated levels of symptom reports in interaction with health anxiety.
  • ItemZeitschriftenaufsatzOpen Access
    Realizing quantitative quasiparticle modeling of skyrmion dynamics in arbitrary potentials
    (2025) Brems, Maarten A.; Sparmann, Tobias; Fröhlich, Simon M.; Dany, Leonie-C.; Rothörl, Jan; Kammerbauer, Fabian; Jefremovas, Elizabeth M.; Farago, Oded; Kläui, Mathias; Virnau, Peter
    We demonstrate fully quantitative Thiele model simulations of magnetic skyrmion dynamics on previously unattainable experimentally relevant large length and time scales by ascertaining the key missing parameters needed to calibrate the experimental and simulation timescales and current-induced forces. Our work allows us to determine complete spatial pinning energy landscapes that enable quantification of experimental studies of diffusion in arbitrary potentials within the Lifson-Jackson framework. Our method enables us to ascertain the timescales, and by isolating the effect of ultralow current density (order 10^{6}  A/m^{2}) generated torques we directly infer the total force acting on the skyrmion for a quantitative modeling.
  • ItemZeitschriftenaufsatzOpen Access
    Strain effects on magnetic compensation and spin reorientation transition of Co/Gd synthetic ferrimagnets
    (2023) Masciocchi, Giovanni; Kools, Thomas J.; Li, Pingzhi; Petrillo, Adrien A. D.; Koopmans, Bert; Lavrijsen, Reinoud; Kehlberger, Andreas; Kläui, Mathias
    Synthetic ferrimagnets are an attractive material class for spintronics as they provide access to all-optical switching of magnetization and, at the same time, allow for ultrafast domain wall motion at angular momentum compensation. In this work, we systematically study the effects of strain on the perpendicular magnetic anisotropy and magnetization compensation of Co/Gd and Co/Gd/Co/Gd synthetic ferrimagnets. First, the spin reorientation transition of a bilayer system is investigated in wedge type samples, where we report an increase in the perpendicular magnetic anisotropy in the presence of in-plane strain. Using a model for magnetostatics and spin reorientation transition in this type of system, we confirm that the observed changes in anisotropy field are mainly due to the Co magnetoelastic anisotropy. Second, the magnetization compensation of a quadlayer is studied. We find that magnetization compensation of this synthetic ferrimagnetic system is not altered by external strain. This confirms the resilience of this material system against strain that may be induced during the integration process, making Co/Gd ferrimagnets suitable candidates for spintronics applications.
  • ItemZeitschriftenaufsatzOpen Access
    Feindbild postmigrantische Gesellschaft : zur Aneignung postkolonialer Argumentationslinien bei der Neuen Rechten
    (2024) Wiegmann, Eva
    Die Vision einer postmigrantischen Gesellschaft schürt in kulturkonservativen Kreisen die Angst vor dem Verlust der eigenen kulturellen Identität. Als Instrument zur Verteidigung des spezifisch Eigenen hat die Neue Rechte die postkolonialen Studien für sich entdeckt. Der Beitrag beleuchtet zum einen das Kulturverständnis der Neuen Rechten und wie es zu der existentiellen Angst vor einem ethnokulturellen Bedeutungsverlust kommt. Zum anderen wird gezeigt, wie sich die Neue Rechte den postkolonialen Identitätsdiskurs aneignet und seine Parameter durch strategische Mimikry verschiebt.
  • ItemAnderer Publikations- oder DokumenttypOpen Access
    Römischer Weinkelterfund an Nahe / Glan : neue Perspektiven zu den Anfängen der deutschen Weinbaugeschichte : Interview von 10. Märs 2025
    (2025) Matheus, Michael; Nickenig, Rudolf
    Faszinierender Römischer Weinkelterfund an Nahe/Glan Neue Perspektiven zu den Anfängen der deutschen Weinbaugeschichte Der Fund einer römischen Weinkelter am Zusammenfluss von Nahe und Glan ist aus weinkulturgeschichtlicher Sicht als eine Sensation zu bewerten. In einem Gespräch mit dem Vorsitzenden des wissenschaftlichen Beirates der Gesellschaft für Geschichte des Weines, Dr. Rudolf Nickenig, erläutert der renommierte Historiker Prof. Dr. Michael Matheus, wie er zu seiner Bewertung der Ausgrabung als römische Kelteranlage kam, welche Probleme es bei der Erhaltung und Sicherung des Fundes gibt, und welche Chancen für die Weinkultur und Weintouristik bestehen. Dieser römische Weinkelterfund, so Matheus, erhärtet die bisher nicht zu beweisende Vermutung, dass die Römer auch in der näheren Umgebung von Mainz, nicht nur im Rheintal, sondern auch an den Nebenflüssen Nahe und Glan Weinbau betrieben haben. Der mit archäologischen Kelterfunden vertraute und zu diesem Thema ausgewiesene Wissenschaftler appelliert auch aufgrund der Erfahrungen mit dieser Fundstätte, dass bei zukünftigen Grabungen im Bereich römischer Landvillen sensibler auf weinhistorische Relikte geachtet wird. In einem ausführlichen Interview (s.www.geschichte-des-weines.de/Roemer- Weinkelter-Nahe.pdf) erläutert Matheus die wissenschaftlichen Methoden, die zur Beweisführung bei der Identifizierung der römischen Kelteranlage eingesetzt wurden. Im Vergleich zu Ausgrabungen an der Mosel in den 1970er Jahren stehen heute modernste archäobotanische, -chemische und materialwissenschaftliche Analysen zur Verfügung, die nicht nur eine zeitliche Einordnung, sondern auch Bestimmung des Verwendungszweckes von Materialien, wie z. B. von Estrichen in Behältern, erlauben. Auf dieser Grundlage gelang der Nachweis, dass es sich in Odernheim um eine römische Weinkelteranlage handelt. Außerdem vergleicht Matheus bisherige römische Weinkelterfunde an der Mosel, in Ungstein (Pfalz) und in Italien wie in Rom an der Via Appia Antica. Spannend für die Weinbranche und für die Weinkulturfreund*innen sind vor allem die weinkulturgeschichtlichen Konsequenzen und Chancen, die sich aus dem Fund ergeben. Vieles spricht dafür, dass die Ausbreitung des Weinbaus in den deutschen Weinbaugebieten anders verlief als bisher angenommen. Für die Weinbauregion an Nahe und Glan, die unmittelbar an Rheinhessen grenzt und historisch zur Nordpfalz zählte, kann der archäologische Weinkelterfund zu einem weintouristischen „Pfund“ werden, wenn man die überraschend gefundene Chance erkennt und nutzt!
  • ItemZeitschriftenaufsatzOpen Access
    Effects of chiral polypeptides on skyrmion stability and dynamics
    (2025) Kapon, Yael; Kammerbauer, Fabian; Balland, Theo; Yochelis, Shira; Kläui, Mathias; Paltiel, Yossi
    Magnetic skyrmions, topologically stabilized chiral spin textures in magnetic thin films, have garnered considerable interest due to their efficient manipulation and resulting potential as efficient nanoscale information carriers. One intriguing approach to address the challenge of tuning skyrmion properties involves using chiral molecules. Chiral molecules can locally manipulate magnetic properties by inducing magnetization through spin exchange interactions and by creating spin currents. Here, Magneto-Optical Kerr Effect (MOKE) microscopy is used to image the impact of chiral polypeptides on chiral magnetic structures. The chiral polypeptides shift the spin reorientation transition temperature, reduce thermal skyrmion motion, and alter the coercive field locally, enhancing skyrmion stability and thus enabling local control. These findings demonstrate the potential of chiral molecules to address challenges for skyrmion based devices, thus paving the way to applications such as the racetrack memory, reservoir computing and others.
  • ItemArbeitspapierOpen Access