We study local consequence relations in modal extensions of product logic over Kripke models with either valued (fuzzy) or crisp accessibility relations. In both settings, we consider semantics over the full class of product algebras as well as over the standard product algebra on [0, 1]. Our main result is a constructive reduction of these modal logics to propositional product logic. As consequences, we prove that all the resulting systems are decidable and standard complete, i.e., the local consequence relation over all product algebras coincides with the one induced by the standard product algebra. In the valued-accessibility case, our methods strengthen previous results on decidability by extending them from theoremhood to arbitrary local consequence relations, and covering standard completeness. In the crisp case, the techniques are substantially different and yield, to the best of our knowledge, the first decidability and standard completeness results for local modal product logics with crisp accessibility relations. (c) 2026 The Author. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
Temperate floodplains rank among Europe's most biodiverse ecosystems, yet land-use change has profoundly transformed them, including large-scale river regulation, canopy closure and the loss of semi-open habitats. While these changes affect biodiversity, it remains unclear whether present-day communities are shaped more by contemporary landscape structure or by historical landscape legacies that persist despite subsequent habitat transformations. Resolving this question is critical for understanding delayed biodiversity responses and guiding effective conservation in dynamic landscapes. We addressed this question across 299 forest stands in a Central European floodplain, using multi-taxon community data on plants, birds, saproxylic beetles, and ants (385, 114, 598, and 46 species, respectively). We quantified the relative contributions of contemporary landscape composition, long-term land-cover change between 1938 and 2009, and spatial predictors to community composition, total species richness, and threatened species richness. Across all taxa and diversity responses, contemporary landscape composition explained more variation than historical land-cover change. Closed-canopy forest cover emerged as a dominant cross-taxon landscape gradient, associated with shifts in community composition and declining species richness, whereas open and semi-open habitats were generally associated with greater diversity. Spatial effects, closely tied to floodplain topography, varied by taxonomic group and were strongest for plants and beetles but relatively weak for birds. Importantly, although the independent contribution of historical land-cover change was generally small, it remained significant for plant and bird communities and was particularly pronounced for threatened species richness. In contrast, historical change had no significant unique effect on overall species richness. This contrast suggests that threatened species retain a stronger signal of historical landscape transformations than overall biodiversity, consistent with persistent landscape legacies and potentially delayed responses to habitat change. Our findings show that contemporary habitat structure best explains floodplain biodiversity, while historical landscape legacies remain especially relevant for species of conservation concern. Effective conservation should therefore combine maintaining heterogeneous habitat mosaics with restoring structurally diverse, semi-open floodplain habitats.
HelD protein, also named HelR (encoded by MSMEG_2174 in Mycobacterium smegmatis), interacts with mycobacterial RNA polymerase (RNAP) and affects rifampicin resistance in Mycobacterium abscessus. Here, we provide data on rifampicin resistance and helD presence in the genomes of other clinically relevant nontuberculous mycobacteria. We show that helD is primarily found in rapidly growing mycobacteria, such as M. smegmatis, where we detected HelD at a subset of promoters that can also associate with CarD and RbpA. Transcriptome analysis of a helD deletion strain revealed that HelD has a dual role in gene regulation: it enhances transcription during exponential growth but reduces it in stationary phase. We show that transcription downregulation in stationary phase is accompanied by decreased amounts of the transcription initiation factors RbpA and CarD. In addition, we characterized HelD-containing RNAP complexes using native cryo-EM. Based on these data, we propose that HelD acts as a general transcription factor that releases stalled RNAP complexes and dissociates RNAP from promoters. HelD demonstrates how a single protein can perform fundamentally different tasks, mediating both antibiotic resistance and efficient transcription, and thereby shaping bacterial adaptability.
This work uncovers a non-intuitive picture of twinning evolution in rolled AZ31 magnesium alloy by combining in-situ neutron diffraction with rotational sampling and EBSD. Contrary to expectations based on nearly uniform Schmid factor distributions for the same grain families around the rotation axis of the specimen, twinning activity exhibits a pronounced orientation selectivity: the strongest twinning-associated response is observed for grains with basal planes perpendicular to the sheet normal direction. Even more intriguingly, the twinning-associated depletion of the parent (0002) orientation population follows a robust power-law scaling with grain orientation density (MRD), with an exponent that remains nearly constant over most of the deformation and increases above approximately 6–7% true strain, indicating a change in how the twinning-associated response is distributed among orientation populations. Unlike commonly reported dynamic power laws associated with intermittent plasticity, this scaling describes a population-based relation and does not resolve individual twinning events. Local twin variant selection is asymmetric, while DIC, EBSD, and supplementary time-resolved observations are consistent with interaction-assisted, potentially autocatalytic twinning across neighboring grains. This behavior is accompanied by the formation of organized mesoscopic twin-rich deformation bands. Together, these findings show that the observed azimuthal twinning response is not described by Schmid factor considerations alone, but also reflects texture, grain interactions, and mesoscopic strain compatibility.
We discuss quantum couplers based on two-dimensional Dirac Hamiltonians. We focus on transport regimes in which Klein tunneling plays a dominant role and suppresses backscattering, yet, the involved interactions act in nontrivial manner on additional degrees of freedom. We show that, at normal incidence, the phenomenon is intimately related to free-particle dynamics through a unitary transformation. This mapping provides a simple analytical framework for describing changes of the polarization of states transmitted through the coupler. The construction is illustrated using armchair graphene nanoribbons, with particular emphasis on an AA-stacked bilayer coupler; a monolayer coupler with proximity-induced exchange interaction is discussed as an alternative realization. We derive explicit expressions for the polarization coefficients and show how the transmitted polarization can be controlled by external interactions. In the bilayer realization, this enables layer switching and conversion between layer and cone polarization. We also analyze transport away from the perfect Klein-tunneling regime, derive analytically the conditions for Fabry–Pérot resonances, and calculate the conductance of the coupler.
