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Odd-parity effect and scale-dependent viscosity in atomic quantum gases
No full textTwo-dimensional electron gases are predicted to possess an anomalous “tomographic” transport regime that is marked by an odd-even effect in the relaxation times, with odd-parity deformations of the Fermi surface becoming long-lived in comparison to even-parity ones. In this work, we establish that neutral two-component atomic Fermi gases also exhibit this tomographic effect. By diagonalizing the Fermi liquid collision integral, we identify odd-parity modes with anomalously long lifetimes below temperatures T≤0.15TF, which is within reach of cold atom experiments. Furthermore, in contrast to electron gases, we find that the odd-even effect in neutral gases is widely tuneable with interactions along the BCS-BEC crossover and is suppressed on the BEC side. We propose as an experimental signature of the odd-even effect the damping rate of quadrupole oscillations, which is anomalously enhanced due to the presence of long-lived odd-parity modes. Our findings suggest that the dynamics of two-dimensional Fermi gases is richer than previously thought and should include additional long-lived modes.publishe
Dynamics of later-life caregiving and health : Insights from biomarker data and cognitive tests
No full textAs populations age and informal caregiving becomes more widespread, the health consequences of providing care are becoming a key concern for societies. Sociological theories of stress appraisal and role strain posit detrimental consequences to the health and wellbeing of caregivers. Conversely, role enhancement theory holds that caregiving can have positive health consequences. Using data from the English Longitudinal Study of Aging (ELSA) collected among adults aged 50 years or older with a follow-up period of up to 20 years (2002–23, 88,225 observations of 20,217 respondents), we examine associations between transitions into and out of caregiving, and two key health outcomes which have been understudied as consequences of caregiving, namely: allostatic load and cognitive functioning. We estimate asymmetric fixed-effects models which model changes in health outcomes as a function of transitions into and out of caregiving while accounting for unobserved between-person heterogeneity. Our results show that caregiving is associated with better cognitive health for both men and women, but not with improved biomarker-based allostatic load. Results do not differ by caregiving intensity. Our findings provide support for role enhancement theory, suggesting that caregivers benefit in terms of cognitive functioning, even if a biomarker-based approach to measuring stress-related health outcome does not corroborate an overall health benefit. We formulate implications for policy-making and directions for future research.publishe
Interplay between genes and social environment : from epigenetics to precision medicine
No full textpublishe
The Future Could be Greener : A Randomized Choice Experiment on Cognitive Alternatives and Sustainable Food Choices
No full textCarbon footprint information via labels has raised interest as a tool to encourage pro-environmental behavior. We propose cognitive alternatives to the environmental status quo (Environmental cognitive alternatives; ECAs), the ability to imagine what a sustainable relationship with nature could look like, to improve the effectiveness of carbon labels. Using a discrete choice experiment with intervention and control groups, we investigate the effect of ECAs on low emission labeled, sustainable choices in a grocery shopping context. German participants (N = 150) were randomly assigned to three groups, activating either cognitive alternatives of a positive relationship with nature, or perceived environmental threat (PET), or nothing in a full control group. In the ECAs activation group, participants chose options with lower carbon emissions compared to the other two groups, and had stronger preferences on rating scales for these options. In the PET activation group, participants also had stronger preferences on rating scales than the control group, but this effect was not found for the choice of options. Activating ECAs might be a promising intervention for promoting sustainable choices, and carbon labeling could be helpful when paired with interventions that activate ECAs.publishe
Complex variation in afrotropical mammal communities with human impact
No full textThe diversity and composition of mammal communities are strongly influenced by human activities, though these relationships may vary across broad scales. Understanding this variation is key to conservation, as it provides a baseline for planning and evaluating management interventions. We assessed variation in the structure and composition of Afrotropical medium and large mammal communities within and outside protected areas, and under varying human impact. We collected data at 512 locations from 22 study sites in 12 Afrotropical countries over 7 years and 3 months (2011–2018) with 164,474 camera trap days in total. Half of these sites are located inside protected areas and half in unprotected areas. The sites are comparable in that they all harbor at least one great ape species, indicating a minimum level of habitat similarity, though they experience varying degrees of human impact. We applied Bayesian Regression models to relate site protection status and the degree of human impact to mammal communities. Protected area status was positively associated with the proportion of all threatened species, independent of the degree of human impact. Similarly, species richness was associated with area protection but was more sensitive to human impact. For all other attributes of the mammal communities, the pattern was more complex. The influence of human impact partially overrides the positive effects of protected area status, resulting in comparable mammal communities being observed both within protected areas and in similarly remote locations outside these areas. We observed a common pattern for large carnivores, whose probability of occurrence declined significantly with increasing human impact, independent of site protection status. Mammal communities benefit from sustainability measures of socio‐economic context that minimize human impact. Our results support the notion that conservation of mammalian species can be achieved by reducing human impact through targeted conservation measures, adopting landscape‐level management strategies, fostering community engagement, and safeguarding remote habitats with high mammal diversity.publishe
Binding Security of Implicitly-Rejecting KEMs and Application to BIKE and HQC
No full textIn this work, we continue the analysis of the binding properties of implicitly-rejecting key-encapsulation mechanisms (KEMs) obtained via the Fujisaki-Okamoto (FO) transform. These binding properties, in earlier literature known under the term robustness, thwart attacks that can arise when using KEMs in complex protocols. Recently, Cremers et al. (CCS'24) introduced a framework for binding notions, encompassing previously existing but also new ones. While implicitly-rejecting FO-KEMs have been analyzed with respect to multiple of these notions, there are still several gaps. We complete the picture by providing positive and negative results for the remaining notions. Further, we show how to apply our results to the code-based KEMs BIKE and HQC, which were round-4 candidates in NIST's PQC standardization process. Through this, we close a second gap as our results complete the analysis of the binding notions for the NIST round-4 KEMs. Finally, we give a modified version of the FO transform that achieves all binding notions.publishe
Sharp Trace and Korn Inequalities for Differential Operators
No full textWe establish sharp trace and Korn-type inequalities that involve vectorial differential operators, the focus being on situations where global singular integral estimates are not available. Starting from a novel approach to sharp Besov boundary traces by Riesz potentials and oscillations that equally applies to p = 1, a case difficult to be handled by harmonic analysis techniques, we then classify boundary trace- and Korn-type inequalities. For p = 1 and so despite the failure of the Calderón-Zygmund theory, we prove that sharp trace estimates can be systematically reduced to full k-th order gradient estimates. Moreover, for 1 < p < ∞, where sharp trace estimates yield Korn-type inequalities on smooth domains, we show for the basically optimal class of John domains that Korn-type inequalities persist – even though the reduction to global Calderón-Zygmund estimates by extension operators might not be possible.publishe
Implementation of field-differential phase-resolved microwave magnetic spectroscopy
No full textMicrowave spectroscopies are central to the investigation of magnetic systems by enabling the identification of dynamical resonance modes and by providing quantitative information on key magnetic parameters. Experiments on magnetization dynamics based on inductive microwave techniques usually rely on either field-modulated power detection or phase-resolved detection using a vector network analyzer. While these two approaches bring separate advantages, they have rarely been combined together. In this work, we develop customized microwave instrumentation combining phase-resolved detection and magnetic field modulation to perform microwave spectroscopy of magnetic systems. We apply this technique to ferromagnetic resonance (FMR), where it enables a quantitative measurement of the magnetic susceptibility in systems with small volume and magnetization. This method of field-differential phase-resolved microwave magnetic spectroscopy is compared with other approaches and is shown to greatly improve the resolution of finely separated FMR peaks and the detection of small signals. Furthermore, we model and characterize comprehensively the inductive coupling of the magnetic system to the microwave circuit, which enables a quantitative analysis of the resonance peaks and the rejection of potential errors originating from too strong permeability, imperfect impedance matching, broadening induced by field inhomogeneity, and varying sample placement.publishe
Introducing the Attribution Stability Indicator : A Measure for Time Series XAI Attributions
No full textGiven the increasing amount and general complexity of time series data in domains such as finance, weather forecasting, and healthcare, there is a growing need for state-of-the-art performance models that can provide interpretable insights into underlying patterns and relationships. Attribution techniques enable the extraction of explanations from time series models to gain insights but are hard to evaluate for their robustness and trustworthiness. We propose the Attribution Stability Indicator (ASI), a measure to incorporate robustness and trustworthiness as properties of attribution techniques for time series into account. We extend a perturbation analysis with correlations of the original time series to the perturbed instance and the attributions to include wanted properties in the measure. We demonstrate the wanted properties based on an analysis of the attributions in a dimension-reduced space and the ASI scores distribution over three whole time series classification datasets.publishe
Responses of naturalized alien plants to soil heterogeneity and competition vary with the global naturalization success of the native competitors
No full text1. Soil heterogeneity (i.e. the heterogeneous distribution of nutrients, soil types or other soil characteristics) has been found to promote the invasion success of naturalized alien plants (i.e. plants that have been introduced by humans to new ranges, where they have established persistent populations) when competing with native plants. However, native species that compete with the naturalized aliens may themselves be naturalized alien species elsewhere. It has also been found that common species, irrespective of whether they are alien or native, benefit more from high resource availability than rare species. Therefore, it remains unknown how regional commonness of alien plants and the extent of the worldwide naturalized geographical distribution of native species impact the invasion process on heterogeneous soils.
2. We considered the geographical distributions of native and alien species in Germany at two scales: commonness (i.e. grid-cell frequency) in Germany and the global naturalized distribution. Then, to test whether the performance of common (n = 7) and rare (n = 7) alien species in Germany depends on soil heterogeneity and on whether the natives they compete with are themselves widely naturalized elsewhere (i.e. outside of Germany; n = 10) or not (n = 5), we conducted a large outdoor pot experiment.
3. We found that the growth of the alien plants, irrespective of whether they are relatively rare or common in Germany, was reduced by competition, and particularly if the native competitor is widely naturalized elsewhere. Consequently, the relative biomass of the alien plants (i.e. the ratio of alien to total biomass) was reduced when growing with a native plant that is widely naturalized elsewhere. Soil heterogeneity overall resulted in a reduced growth, but this was not the case for the common aliens when they were competing with a native that is widely naturalized elsewhere.
4. Synthesis. Our findings thus show that soil heterogeneity does not always promote alien plants over native plants. Moreover, our findings show that when testing the effects of native species on naturalized alien species, it is important to consider whether the native species themselves are widely naturalized around the globe or not.publishe