Scene recognition is a core sensory capacity that enables humans to adaptively interact with their environment. Despite substantial progress in the understanding of the neural representations underlying scene recognition, the relevance of these representations for behavior given varying task demands remains unknown. To address this, we aimed to identify behaviorally relevant scene representations, to characterize them in terms of their underlying visual features, and to reveal how they vary across different tasks. We recorded fMRI data while human participants viewed scenes and linked brain responses to behavior in three tasks acquired in separate sessions: man-made/natural categorization, basic-level categorization, and fixation color discrimination. We found correlations between categorization response times and scene-specific brain responses, quantified as the distance to a hyperplane derived from a multivariate classifier. Across tasks, these effects were found in largely distinct parts of the ventral visual stream. This suggests that different scene representations are relevant for behavior depending on the task. Next, using deep neural networks as a proxy for visual feature representations, we found that intermediate layers mediated the relationship between scene representations and behavior for both categorization tasks, indicating a contribution of mid-level visual features to these representations. Finally, we observed opposite patterns of brain-behavior correlations in the man-made/natural and the fixation task, indicating interference of representations with behavior for task demands that do not align with the content of representations. Together, these results reveal the spatial extent, content, and task-dependence of the visual representations that mediate behavior in complex scenes.
View lessRegional regime complexity has long been on the rise and carries a series of potential negative effects, such as waste of resources or reduced effectiveness of regional governance. This article investigates a specific strategy of how states cope with regime complexity, namely by exiting regional international organizations (RIOs). We develop hypotheses on how different types of regional regime complexity influence the chances for exits to occur and theorize interaction effects. The analysis reveals that higher levels of membership- and competency-based regime complexity as well as RIO incompatibility increase the likelihood of state withdrawals. In addition, state characteristics moderate this effect and influence who leaves which organization. Most importantly, smaller rather are less able to shape RIO policies and activities and have fewer capacities to implement them and are thus more likely to exit one of the organizations when being member in many overlapping RIOs. By contrast, powerful states can better navigate regime complexity and avoid negative side-effects and are therefore less inclined to withdraw from RIOs in situations of high regional regime complexity.
View lessBy simulation and asymptotic theory, we investigate the transition-path time of a one-dimensional finite-mass reaction coordinate crossing a double-well potential in the presence of non-Markovian friction. First, we consider single-exponential memory kernels and demonstrate that memory accelerates transition paths compared to the Markovian case, especially in the low-mass/high-friction limit. Then, we generalize to multi-exponential kernels and construct an asymptotic formula for the transition-path time that compares well with simulation data.
View lessIn molecular physics, it is often necessary to average over the orientation of molecules when calculating observables, in particular when modeling experiments in the liquid or gas phase. Evaluated in terms of Euler angles, this is closely related to integration over two- or three-dimensional unit spheres, a common problem discussed in numerical analysis. The computational cost of the integration depends significantly on the quadrature method, making the selection of an appropriate method crucial for the feasibility of simulations. After reviewing several classes of spherical quadrature methods in terms of their efficiency and error distribution, we derive guidelines for choosing the best quadrature method for orientation averages and illustrate these with three examples from chiral molecule physics. While Gauss quadratures allow for achieving numerically exact integration for a wide range of applications, other methods offer advantages in specific circumstances. Our guidelines can also be applied to higher-dimensional spherical domains and other geometries. We also present a Python package providing a flexible interface to a variety of quadrature methods.
View lessWe investigate the anisotropic frequency-dependent dielectric, THz and IR response of liquid water confined between two planar graphene sheets with force-field- and density-functional-theory-based molecular dynamics simulations. Using spatially resolved anisotropic spectra, we demonstrate the critical role of the volume over which the spectral response is integrated when reporting spatially averaged electric susceptibilities. To analyze the spectra, we introduce a unique decomposition into bulk, interfacial, and confinement contributions, which reveals that confinement effects on the spectra occur only for systems with graphene separation below 1.4 nm, for all frequencies. Based on this decomposition, we discuss the molecular origin of the main absorption features of nanoconfined water from the GHz to the IR regime. We show that, at low frequencies, the 15 GHz Debye peak of interfacial water is redshifted due to a slowdown of collective water reorientations. At high frequencies, the OH stretch at 100 THz blue shifts and a signature of free OH groups emerges, while the HOH bend mode at 50 THz is redshifted. Strikingly, in nanoconfinement, the 20 THz libration band shifts to below 15 THz and broadens drastically, spanning two orders of magnitude in frequency. These results are rationalized by the collective water motion and the structure of the hydrogen-bond network at the water–graphene interface and in two-dimensional water layers, which reveals the intricate behavior of nanoconfined water and its spectral properties.
View lessA dichloromethane (DCM) extract of carrot roots was found to stimulate insulin-dependent glucose uptake (GU) in adipocytes in a dose dependent manner. Bioassay-guided fractionation of the DCM extract resulted in the isolation of the polyacetylenes falcarinol and falcarindiol. Both polyacetylenes were able to significantly stimulate basal and/or insulin-dependent GU in 3T3-L1 adipocytes and porcine myotube cell cultures in a dose-dependent manner. Falcarindiol increased peroxisome proliferator-activated receptor (PPAR)γ-mediated transactivation significantly at concentrations of 3, 10 and 30 μM, while PPARγ-mediated transactivation by falcarinol was only observed at 10 μM. Docking studies accordingly indicated that falcarindiol binds to the ligand binding domain of PPARγ with higher affinity than falcarinol and that both polyacetylenes exhibit characteristics of PPARγ partial agonists. Falcarinol was shown to inhibit adipocyte differentiation as evident by gene expression studies and Oil Red O staining, whereas falcarindiol did not inhibit adipocyte differentiation, which indicates that these polyacetylenes have distinct modes of action. The results of the present study suggest that falcarinol and falcarindiol may represent scaffolds for novel partial PPARγ agonists with possible antidiabetic properties.
View less24 unbekannte Aufsätze Julius Stindes aus Zeitschriften und Zeitungen von 1874 bis 1902.
Context. The increased brightness temperature of young rocky protoplanets during their magma ocean epoch makes them potentially amenable to atmospheric characterization at distances from the Solar System far greater than thermally equilibrated terrestrial exoplanets, offering observational opportunities for unique insights into the origin of secondary atmospheres and the near surface conditions of prebiotic environments.
Aims. The Large Interferometer For Exoplanets (LIFE) mission will employ a space-based midinfrared nulling interferometer to directly measure the thermal emission of terrestrial exoplanets. In this work, we seek to assess the capabilities of various instrumental design choices of the LIFE mission concept for the detection of cooling protoplanets with transient high-temperature magma ocean atmospheres at the tail end of planetary accretion. In particular, we investigate the minimum integration times necessary to detect transient magma ocean exoplanets in young stellar associations in the Solar neighborhood.
Methods. Using the LIFE mission instrument simulator (LIFEsim), we assessed how specific instrumental parameters and design choices, such as wavelength coverage, aperture diameter, and photon throughput, facilitate or disadvantage the detection of protoplan-ets. We focused on the observational sensitivities of distance to the observed planetary system, protoplanet brightness temperature (using a blackbody assumption), and orbital distance of the potential protoplanets around both G- and M-dwarf stars.
Results. Our simulations suggest that LIFE will be able to detect (S/N ≥ 7) hot protoplanets in young stellar associations up to distances of 100 pc from the Solar System for reasonable integration times (up to a few hours). Detection of an Earth-sized protoplanet orbiting a Solar-sized host star at 1 AU requires less than 30 minutes of integration time. M-dwarfs generally need shorter integration times. The contribution from wavelength regions smaller than 6 µm is important for decreasing the detection threshold and discriminating emission temperatures.
Conclusions. The LIFE mission is capable of detecting cooling terrestrial protoplanets within minutes to hours in several local young stellar associations hosting potential targets. The anticipated compositional range of magma ocean atmospheres motivates further architectural design studies to characterize the crucial transition from primary to secondary atmospheres.
View lessContext. Hot Jupiters are giant planets subject to intense stellar radiation. The physical and chemical properties of their atmosphere make them the most amenable targets for atmospheric characterization.
Aims. In this paper we analyze the photometry collected during the secondary eclipses of the hot Jupiter WASP-3 b by CHEOPS, TESS, and Spitzer. Our aim is to characterize the atmosphere of the planet by measuring the secondary eclipse depth in several passbands and constrain the planetary dayside spectrum.
Methods. We updated the radius and the ephemeris of WASP-3 b by analyzing the transit photometry collected by CHEOPS and TESS. We also analyzed the CHEOPS, TESS, and Spitzer photometry of the occultations of the planet, measuring the eclipse depth at different wavelengths.
Results. Our update of the stellar and planetary properties is consistent with previous works. The analysis of the occultations returns an eclipse depth of 92±21 ppm in the CHEOPS passband, 83±27 ppm for TESS, and >2000 ppm in the IRAC 1-2-4 Spitzer passbands. Using the eclipse depths in the Spitzer bands, we propose a set of likely emission spectra that constrain the emission contribution in the CHEOPS and TESS passbands to approximately a few dozen parts per million. This allowed us to measure a geometric albedo of 0.21±0.07 in the CHEOPS passband, while the TESS data lead to a 95% upper limit of ∼0.2.
Conclusions. WASP-3 b belongs to the group of ultra-hot Jupiters that are characterized by a low Bond albedo (<0.3±0.1), as predicted by different atmospheric models. On the other hand, it seems to efficiently recirculate the absorbed stellar energy, which is not typical for similar, highly irradiated planets. To explain this inconsistency, we propose that other energy recirculation mechanisms are at play besides advection (for example, the dissociation and recombination of H2). Another possibility is that the observations in different bandpasses probe different atmospheric layers; this would make the atmospheric analysis difficult without an appropriate modeling of the thermal emission spectrum of WASP-3 b, which is not feasible with the limited spectroscopic data available to date.
View lessContext. HR 10 has only recently been identified as a binary system. Previously thought to be an A-type shell star, it appears that both components are fast-rotating A-type stars, each presenting a circumstellar envelope. Although showing complex photometric variability, spectroscopic observations of the metallic absorption lines reveal variation explained by the binarity, but not indicative of debris-disc inhomogeneities or sublimating exocomets. On the other hand, the properties of the two stars make them potential δ Scuti pulsators.
Aims. The system has been observed in two sectors by the TESS satellite, and was the target of three observing visits by CHEOPS. Thanks to these new data, we aim to further characterise the stellar properties of the two components. In particular, we aim to decipher the extent to which the photometric variability can be attributed to a stellar origin. In complement, we searched in the lightcurves for transient-type events that could reveal debris discs or exocomets.
Methods. We analysed the photometric variability of both the TESS and CHEOPS datasets in detail. We first performed a frequency analysis to identify and list all the periodic signals that may be related to stellar oscillations or surface variability. The signals identified as resulting from the stellar variability were then removed from the lightcurves in order to search for transient events in the residuals.
Results. We report the detection of δ Scuti pulsations in both the TESS and CHEOPS data, but we cannot definitively identify which of the components is the pulsating star. In both datasets, we find flicker noise with the characteristics of a stellar granulation signal. However, it remains difficult to firmly attribute it to actual stellar granulation from convection, given the very thin surface convective zones predicted for both stars. Finally, we report probable detection of transient events in the CHEOPS data, without clear evidence of their origin.
View lessReplicating existing models and their key results not only adds credibility to the original work, it also allows modellers to start model development from an existing approach rather than from scratch. New theory can then be developed by changing the assumptions or scenarios tested, or by carrying out more in-depth analysis of the model. However, model replication can be challenging if the original model description is incomplete or ambiguous. Here we show that the use of standards can facilitate and speed up replication: the ODD protocol for describing models, and NetLogo, an easy-to-learn but powerful software platform and language for implementing agent-based models. To demonstrate the benefits of this approach, we conducted a replication experiment on 18 agent-based models from different disciplines. The researchers doing the replications had no or little previous experience using ODD and NetLogo. Their task was to rewrite the original model description using ODD, implement the model in NetLogo and try to replicate at least one exemplary main result. They were also asked to produce, if time allowed, some initial new results with the replicated model, and to record the total time spent on the replication exercise. Replication was successful for 15 out of 18 models. The time taken varied between 2 and 12 days, with an average of 5 days. ODD helped to systematically scan the original model description, while NetLogo proved easy and quick to learn, but difficult to debug when implementation problems arose. Although most of the models replicated were relatively simple, we conclude that even for more complex models it can be useful to use ODD and NetLogo for replication, at least for developing a prototype to help decide how to proceed with the replicated model. Overall, the use of both, standard approaches such as ODD and easy to learn but powerful software such as NetLogo, can promote coherence and efficiency within and between different models and modelling communities. Imagine if all modellers spoke ODD and NetLogo as a common language or lingua franca.
View lessThe lncRNA Crossfirre was identified as an imprinted X-linked gene, and is transcribed antisense to the trans-acting lncRNA Firre. The Firre locus forms an inactive-X-specific interaction with Dxz4, both loci providing the platform for the largest conserved chromatin structures. Here, we characterize the epigenetic profile of these loci, revealing them as the most female-specific accessible regions genome-wide. To address their in vivo role, we perform one of the largest X-linked knockout studies by deleting Crossfirre, Firre, and Dxz4 individually and in combination. Despite their distinct epigenetic features observed on the X chromosome, our allele-specific analysis uncovers these loci as dispensable for imprinted and random X chromosome inactivation. However, we provide evidence that Crossfirre affects autosomal gene regulation but only in combination with Firre. To shed light on the functional role of these sex-specific loci, we perform an extensive standardized phenotyping pipeline and uncover diverse knockout and sex-specific phenotypes. Collectively, our study provides the foundation for exploring the intricate interplay of conserved X-linked loci in vivo.
View lessIntroduction
Increasing soil organic carbon (SOC) in croplands is a natural climate mitigation effort that can also enhance crop yields. However, there is a lack of comprehensive field studies examining the impact of SOC on crop yields across wide climatic, soil, and farming gradients. Furthermore, it is largely unknown how water retention, soil microbial diversity, and nutrient availability modulate the SOC-crop yield relationship.
Materials and Methods
We conducted an observational study across 127 cereal fields along a 3000 km north-south gradient in Europe, measured topsoil (0–20 cm) organic C content, and collected data on climate, soil properties, crop yield and farming practices. Additionally, we explored the relationship between crop yield, particulate organic carbon (POC) and mineral-associated organic carbon (MAOC) contents at three soil depths (0–20, 20–40 and 40–60 cm) in a subset of sites.
Results
Relative yield increases levelled off at 1.4% SOC, indicating an optimal SOC content for cereals along a European gradient. The quadratic relationship between SOC and cereal yield was conspicuous even after controlling for large differences in climate, soil and farming practices across countries. The relationship varied significantly across soil depths and C fractions. MAOC dominated the SOC pool, and was significantly related to relative yield up to an optimal level that varied with soil depth. Soil microbial diversity and nutrient availability emerged as main drivers of the SOC-yield relationship, while water retention did not exhibit a notable influence.
Conclusions
Our study demonstrates that SOC is as a key determinant of cereal yield along a European gradient, and identifying this threshold can inform soil management strategies for improved carbon capture based on initial SOC levels. Nevertheless, the complex SOC-yield relationship highlights the necessity for tailored soil management strategies that consider specific site conditions to optimize C storage and crop yield.
View lessDespite the multifaceted and diverse challenges that refugees, migrants, and asylum-seekers experience when entering a new country, they remain notably underrepresented in the evaluation and understanding of the health and wellbeing impacts of outdoor health interventions. We addressed this knowledge gap by a mixed-methods evaluation (questionnaires, focus groups and photo elicitation activity) facilitated by a community researcher. Qualitative data (focus groups and photo elicitation activity) revealed that the participants saw the social component of outdoor activities as a critical factor in improving their wellbeing, an insight not captured by established quantitative wellbeing scales. Given the diverse backgrounds of refugee, migrant, and asylum-seeker populations, we underline the importance of a transdisciplinary, collaborative, and mixed-methods research approach.
View lessMany super-Earths are on very short orbits around their host star and, therefore, more likely to be tidally locked. Because this locking can lead to a strong contrast between the dayside and nightside surface temperatures, these super-Earths could exhibit mantle convection patterns and tectonics that could differ significantly from those observed in the present-day solar system. The presence of an atmosphere, however, would allow transport of heat from the dayside toward the nightside and thereby reduce the surface temperature contrast between the two hemispheres. On rocky planets, atmospheric and geodynamic regimes are closely linked, which directly connects the question of atmospheric thickness to the potential interior dynamics of the planet. Here, we study the interior dynamics of super-Earth GJ 486b (R=1.34 R circle plus, M=3.0 M circle plus, Teq approximate to 700 K), which is one of the most suitable M-dwarf super-Earth candidates for retaining an atmosphere produced by degassing from the mantle and magma ocean. We investigate how the geodynamic regime of GJ 486b is influenced by different surface temperature contrasts by varying possible atmospheric circulation regimes. We also investigate how the strength of the lithosphere affects the convection pattern. We find that hemispheric tectonics, the surface expression of degree-1 convection with downwellings forming on one hemisphere and upwelling material rising on the opposite hemisphere, is a consequence of the strong lithosphere rather than surface temperature contrast. Anchored hemispheric tectonics, where downwellings und upwellings have a preferred (day/night) hemisphere, is favored for strong temperature contrasts between the dayside and nightside and higher surface temperatures.
View lessCryomyces antarcticus , a melanized cryptoendolithic fungus endemic to Antarctica, can tolerate environmental conditions as severe as those in space. Particularly, its ability to withstand ionizing radiation has been attributed to the presence of thick and highly melanized cell walls, which—according to a previous investigation—may contain both 1,8‐dihydroxynaphthalene (DHN) and L‐3,4 dihydroxyphenylalanine (L‐DOPA) melanin. The genes putatively involved in the synthesis of DHN melanin were identified in the genome of C. antarcticus. Most important is capks1 encoding a non‐reducing polyketide synthase (PKS) and being the ortholog of the functionally characterized kppks1 from the rock‐inhabiting fungus Knufia petricola . The co‐expression of CaPKS1 or KpPKS1 with a 4′‐phosphopantetheinyl transferase in Saccharomyces cerevisiae resulted in the formation of a yellowish pigment, suggesting that CaPKS1 is the enzyme providing the precursor for DHN melanin. To dissect the composition and function of the melanin layer in the outer cell wall of C. antarcticus , non‐melanized mutants were generated by CRISPR/Cas9‐mediated genome editing. Notwithstanding its slow growth (up to months), three independent non‐melanized Δ capks1 mutants were obtained. The mutants exhibited growth similar to the wild type and a light pinkish pigmentation, which is presumably due to carotenoids. Interestingly, visible light had an adverse effect on growth of both melanized wild‐type and non‐melanized Δ capks1 strains. Further evidence that light can pass the melanized cell walls derives from a mutant expressing a H2B‐GFP fusion protein, which can be detected by fluorescence microscopy. In conclusion, the study reports on the first genetic manipulation of C. antarcticus , resulting in non‐melanized mutants and demonstrating that the melanin is rather of the DHN type. These mutants will allow to elucidate the relevance of melanization for surviving extreme conditions found in the natural habitat as well as in space.
View lessTopical treatment of oral inflammatory diseases is challenging due to the intrinsic physicochemical barriers of the mucosa and the continuous flow of saliva, which dilute drugs and limit their bioavailability. Nanocarrier technology can be an innovative approach to circumvent these problems and thus improve the efficacy of topical drug delivery to the mucosa. Core‐multishell (CMS) nanocarriers are putative delivery systems with high biocompatibility and the ability to adhere to and penetrate the oral mucosa. Ester‐based CMS nanocarriers release the anti‐inflammatory compound dexamethasone (Dx) more efficiently than a conventional cream. Mussel‐inspired functionalization of a CMS nanocarrier with catechol further improves the adhesion of the nanocarrier and may enhance the efficacy of the loaded drugs. In the present study, the properties of the ester‐based CMS 10‐E‐15‐350 nanocarrier (CMS‐NC) are further evaluated in comparison to the catechol‐functionalized variant (CMS‐C0.08). While the mucoadhesion of CMS‐NC is inhibited by saliva, CMS‐C0.08 exhibits better mucoadhesion in the presence of saliva. Due to the improved adhesion properties, CMS‐C0.08 loaded with dexamethasone (Dx‐CMS‐C0.08) shows a better anti‐inflammatory effect than Dx‐CMS‐NC when applied dynamically. These results highlight the superiority of CMS‐C0.08 over CMS‐NC as an innovative drug delivery system (DDS) for the treatment of oral mucosal diseases.
View lessMany of the world's rifts and rifted margins have developed within former orogens. The South China Sea (SCS) formed during Cenozoic rifting by utilizing pre‐existing orogenic structures, like thrust faults, thickened crust, and corresponding thermal weaknesses. The mechanisms explaining how inherited structures influence the spatiotemporal evolution of a rift remain a topic of on‐going research. Here, we explore the impact of orogenic inheritance on rift evolution through a numerical forward model that reproduces geodynamic and landscape evolution processes. By imposing time‐dependent phases of shortening and extension, we model rifted margin formation that is consistent with the available geological and geophysical observations of the SCS. Our numerical models allow us to identify thrust faults that are reactivated as normal faults during extensional phases. Not all pre‐existing thrust faults, however, undergo full reactivation, as their behavior is influenced by variations in lithospheric strength and the pre‐existing structural discontinuities. We further show that inherited orogenic structures compete with each other during extensional reactivation and ultimately govern the location of continental breakup. Our results provide valuable insights into the broader implications of inherited orogenic structures and how they affect subsequent rift system evolution.
View lessPublic administration in governments strives to develop forward‐looking capacities. Foresight has come to the fore as a set of practices that is mobilized to counter political myopia. Despite this increasing interest in governmental foresight, research suggests that diverging institutional practices, organizational structures, and epistemic cultures between foresight practices and policy‐making result in loose coupling. This article aims to contribute to understanding these complicated foresight‐policy interactions. To this end, we draw on findings from public administration scholarship. The concept of institutionalization is employed to analyze how foresight aligns with working practices and routines in government. Based on an in‐depth case study on the institutionalization of foresight practices within the German Federal Government, we demonstrate that scrutinizing the multiple dimensions of institutionalization helps not only to understand where and why loose ends occur but also provides new insights into some of the causes of the lacking impact. The article does not aim to provide an easy fix. Instead, we want to sensitize foresight practitioners, reduce both disappointment and overstating regarding the role of foresight in policy‐making, and provide a nuanced understanding of foresight practices in government.
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