Czech Academy of Sciences

Despite significant advances in the development of biocompatible platforms, such as scaffolds, films, and hydrogels, a challenge remains in formulating films with the right balance of mechanical properties and bioactivity. Herein, we developed biocompatible composite films based on polycaprolactone (PCL), MXene, and gelatin that can be utilized for biomedical applications. PCL and gelatin (from bovine, fish, and porcine skin) were used to design the biocompatible matrix, while MXenes were used as a filler to enhance the mechanical and biological properties of the films. We investigated the influence of these three types of gelatin on the chemical structure, morphology, physicochemical properties, cytotoxicity, biocompatibility, and cell growth. All the films exhibited high tensile strength, ranging from 5 to 10 MPa. The incorporation of a relatively small content of MXene (0.5 wt%) altered the tensile properties of the films with the lower gelatin contents (12-15 wt%). SAXS analysis revealed that the nanometer-scale lamellar stack structures characteristic of PCL, consisting of alternating crystalline and amorphous lamellae, were present in all samples and exhibited a morphology identical to that of neat PCL. In contrast, WAXS showed that the relative intensities of individual PCL reflections varied with sample composition, indicating a preferential orientation of PCL crystallites-and consequently of the lamellar stacks-particularly, in MXene-containing samples. The SEM/SE micrographs displayed a coarse morphology of gelatin nanoparticles in the PCL matrix, and the structure coarseness decreased in the following order: PCL/MX/fish gelatin > PCL/MX/bovine gelatin > PCL/MX/porcine gelatin. Invitro, cell culture experiments with SAOS-2 cells revealed that cell confluence was relatively high on samples with the 14.5 wt% porcine gelatin.

The mitochondrial FoF1-ATP synthase is a reversible nanomachine that normally produces ATP via oxidative phosphorylation but under stress conditions it can reverse to maintain the mitochondrial membrane potential at the expense of ATP, a process regulated by the conserved inhibitory factor 1 (IF1). We show that ATP synthase reversal also occurs during in vitro-induced differentiation of the unicellular parasite Trypanosoma brucei, partially mirroring events in the tsetse fly. Differentiation of insect forms is marked by increased expression of alternative oxidase and reduced levels of trypanosomal IF1 (TbIF1), changes that may promote ATP synthase reversal. Parasites lacking TbIF1 efficiently progressed to the mammalian-infective form, coinciding with increased ATP synthase reversal, a higher ADP/ATP ratio, elevated phosphorylation of AMP-activated protein kinase (AMPK), enhanced proline-supported respiration, and increased mitochondrial and cellular reactive oxygen species (ROS). In contrast, inducible TbIF1 overexpression diminished these hallmarks and locked parasites in the initial insect stage. Our findings reveal that TbIF1 downregulation enables life cycle progression and underscore a regulatory role for the ATP synthase-IF1 axis.

Vertical deformation is the most discriminating observable of the seismic cycle in subduction zones, but its complex measurement and contamination by multiple controlling processes have limited its exploitation. While horizontal displacements primarily reflect interplate coupling, vertical signals encode the competition among elastic megathrust loading, plate tectonic forcing, mantle flow and relaxation, and long-wavelength mass redistribution within the upper plate and forearc. Advances in satellite geodesy now allow vertical deformation rates to be resolved with sufficient precision and spatial coherence to provide new constraints on long-standing conceptual models of interseismic deformation. Recent observations reveal the existence of a secondary zone of interseismic subsidence (SZIS) in Cascadia, Nankai, Japan Trench, and Southern Chile. We use new data and models to assess the persistence of a SZIS and quantify and unravel its physical controls.Using multi-track InSAR rate maps in northern Chile, we identify an inter-seismic secondary zone of subsidence landward of the primary coastal uplift belt. The presence of this SZIS supports the existence of a persistent secondary zone of interseismic subsidence. However, within the classical backslip framework, the elastic half-space predicts a slow monotonic transition from coastal uplift to inland subsidence. We show that it cannot reproduce the observed secondary trough without invoking unphysical coupling distributions or implausible fault geometries. The discrepancy is therefore not parametric, but conceptual. Interestingly, the existence of a SZIS was first predicted by our numerical seismotectonic models (van Dinther et al., PAGEO, 2019). We use these cross-scale visco-elasto-plastic models to demonstrate the critical role of a visco-elastic lower crust, which allows for an elastic upper crust that is thin enough to bulge under compression transferred across a coupled megathrust. We find that this mechanism is important, but it is not the only relevant mechanism. To quantify and detangle the physical mechanisms in more detail, we build a data-driven model of Northern Chile and aim to explain lateral variations along our observed segment. We integrate high-resolution earthquake catalogue, seismic tomography, and gravity anomaly observations to constrain slab geometry, forearc rheology, density structure, and seismogenic zone dimensions. Our fully dynamic visco-elasto-plastic earthquake cycle model with invariant rate-and-state friction resolves sequences of quasi-periodic earthquakes and can build topography over them. Through that, we aim to explain the presence of a SZIS also in our early geomorphic and geological interpretations of upper-plate deformation. Those multi-scale observations support that vertical surface displacements are not only governed by elastic rebound of megathrust faulting but also include a long-term long-wavelength deformation signal possibly related to position-dependent buckling of the upper plate.We argue that, together with the existence of a persistent secondary zone of coseismic uplift of the largest earthquakes, such a secondary zone of deformation is a persistent and characteristic feature of seismic cycle deformation in subduction zones. This primary diagnostic will allow for a reinterpretation of the mechanics of subduction through an extension of the canonical backslip surface-deformation model.

We introduce SpectralPINN, a hybrid pseudo-spectral/physics-informed neural network (PINN) solver for Kerr quasinormal modes that targets the Teukolsky equation in both the separated (radial/angular) and joint two-dimensional formulations. The solver replaces standard neural activation functions with Chebyshev polynomials of the first kind and supports both soft — via loss penalties — and hard — enforced by analytic masks — implementations of Leaver's normalization. Benchmarking against Leaver's continued-fraction method shows cumulative (real+imaginary part) relative frequency errors of ∼ 0.001% for the separated formulation with hard normalization, ∼ 0.1% for both the soft separated and soft joint formulations, and ∼ 0.01% for the hard joint case. Exploiting our ability to solve the joint equation, we add a small quadrupolar perturbation to the Teukolsky operator, effectively rendering the problem non-separable. The resulting perturbed quasinormal modes are compared against the expected precision of the Einstein Telescope, allowing us to constrain the magnitude of the perturbation. These proof-of-concept results demonstrate that hybrid spectral-PINN solvers can provide a flexible pathway to quasinormal spectra in settings where separability, asymptotics, or field content become more intricate and high accuracy is required.

Across the planet, angiosperm diversification has been shaped by palaeoclimates and biotic interactions, particularly with pollinators, leaving signatures in the angiosperm age structure. Regional floras represent biased samples of this global diversification shaped by dispersal, extinction and environmental filtering, yet it remains unclear whether floristic age structure reflects pollination strategies or their interaction with palaeoclimates. We constructed a 97% resolved phylogeny of all 1,178 angiosperms in the Netherlands and characterized age structure of eight pollination syndromes by standardized epoch-specific lineage diversities (stELDs) quantifying the proportional increase in lineages per 10-Myr interval. Overall, stELDs peaked under the coldest intervals and were lowest for intermediate-temperature intervals (geological age alone had no effect). This age structure was strongest in wind-pollinated species. Resolving insect pollination into six syndromes revealed strong heterogeneity: lepidoptera-pollination was most strongly associated with warmest palaeotemperatures, bumblebee and wasp-pollination under intermediate temperatures, and fly, lepidoptera and beetle-pollination under coldest temperatures. Paleotemperature signatures correlated positively with contemporary seasonal flowering temperatures, indicating conserved thermal niches across ecological and macroevolutionary timescales. We suggest that temperate floras reflect both recent cold-house diversification of wind- and certain insect-pollinated lineages and earlier warm-house radiations of lineages pollinated by older insect clades. Phylogenetic age structures permit detecting such patterns.

ABSTRACT This study examined how sexual orientation stereotypes and perceived norms shape young gay and straight men's perceptions of motivations and barriers to interest in early childhood education and care (ECEC) careers. Gay and straight men ( N = 364) estimated interest and then reported barriers and motivations influencing men's interest in childcare work; either for themselves, gay men, or straight men. Men overestimated gay men's interest in childcare work, regardless of their own sexual orientation. As key barriers, participants cited the low salary, poor working conditions, and the gendered association of childcare with femininity, whereas key motivators were positive interactions with children, salary increases, and intrinsic rewards associated with a care‐oriented career. Patterns of distorted norm perception and sexual orientation stereotyping emerged: straight men believed traditional masculinity norms discouraged other straight men more than themselves (i.e., pluralistic ignorance), and gay men overestimated communal motivations of other gay men. These findings highlight how sexual orientation stereotypes and misperceptions of norms reinforce occupational segregation. The discussion addresses the implications of these dynamics for diversifying the ECEC workforce and calls for interventions that challenge restrictive identity‐based assumptions about caregiving roles.