Stockholm University

Depression in old age often has a poor clinical course, although there is substantial variability in depressive symptom trajectories. We aimed to characterise old-age depressive symptom trajectories, assess their multifactorial correlates, and their impact on mortality. We used cohort data from 2118 dementia-free community-dwelling adults aged ≥60years participating in the Swedish National study on Aging and Care in Kungsholmen (SNAC-K). Depressive symptoms were evaluated using the Montgomery-Åsberg Depression Rating Scale at baseline and 1-3 follow-ups over 9years. Sociodemographic (age, sex, marital status, socioeconomic status), psychosocial (social connections and support), clinical (multimorbidity), and functional (gait speed; cognitive impairment) factors at baseline were considered as trajectory correlates. Generalised growth mixture models and multinomial logit models estimated depression trajectories and their correlates. Cox proportional hazard models estimated all-cause mortality risk. Three trajectory classes emerged: low, increasing, and U-shaped trajectories of depressive symptoms. Compared to the low trajectory, socioeconomic status involving high financial strain and poor social support was more common in the increasing and U-shaped trajectories. Slow gait speed was linked to higher odds of increasing depressive symptoms, while greater multimorbidity was associated with the U-shaped trajectory. The increasing and U-shaped trajectories were associated with higher mortality risk, and the association for increasing was robust to the adjustment of covariates. Depressive symptom trajectories in late life are heterogeneous and linked to diverse socio-economic, clinical, and functional factors, some of which are trajectory-specific. Given its association with mortality, older people should be carefully monitored for depressive symptomatology.

How communities are structured into functional groups and trophic layers is key to understanding ecosystem functioning. Nonetheless, we lack insights about spatiotemporal variation in guild composition of communities and its causes. To investigate spatial and temporal patterns and drivers of variation in insect feeding guilds, we combined data from a nationwide survey of Swedish insects using Malaise traps and DNA metabarcoding with a comprehensive trait database. We assigned species into one of three feeding guilds (phytophages, saprophages, predators) or into one of three associated parasitoid guilds. We then analysed patterns in species richness for each guild. Species richness declined with latitude in all guilds. Beyond this gradient, local variation in species richness matched between hosts and their parasitoids. Yet, hosts and their parasitoids responded differently to habitat. The phenological peak of parasitoid species richness appeared later than the peak of their hosts, but the length of time lags varied among guilds. Spatiotemporal patterns were driven by guild-specific responses to temperature, though much variation remained between seasons and locations even when controlling for temperature. Overall, these patterns suggest that shifts in both climate and land use may alter the synchrony of insect trophic layers, with unknown consequences.

Understanding where blue carbon habitats occur and how they are affected by human activity contributes to effective management of natural carbon sinks. Here, we compiled geographical data for Sweden to map the distribution of coastal vegetated blue carbon (BC) habitats. The mapping effort focused on well-recognised (salt marshes and seagrass meadows) and emergent BC habitats (other rooted submerged macrophytes and forested wetlands). We also estimated the exposure to anthropogenic pressures on coastal BC habitats based on their proximity to land-based human activities, and subsequently, the portion of these BC habitats that were located within protected areas. The total area of BC habitats was estimated to around 1850 km2, corresponding to ca. 35% of the Swedish coast. Seagrass meadows and other rooted submerged macrophytes were dominating, covering about 1500 km2. Around 22% of the mapped BC habitats were expected to be exposed to high pressures from land-based human activities due to their location, while BC habitats within protected areas were often less exposed. This nationwide assessment of coastal vegetated BC habitats accentuates the need for strengthening conservation prioritisation to maximise the carbon storage potential of BC habitats.

We study optimal price setting by a monopolist in an infinite horizon model with stochastic costs, moderate inflation, and costly price adjustment. For realistic parameters, chosen to replicate observed frequencies of price changes, the model fits numerically several empirical regularities. In particular, price reductions are larger but less frequent than price increases, and prices respond considerably faster to cost increases than to cost decreases. The associated kink in the steady state short-run Phillips curve implies that the output loss associated with a small negative in‡ation surprise is about twice as large as the output gain associated with a small positive inflation surprise.

As platforms for dialogue, art-science collaborations hold the potential to cross disciplinary boundaries to better understand and engage the public in addressing sustainability challenges. Moving beyond documenting outcomes, this study details how researchers and composers combined science communication and artistic expression to co-produce performances as part of the Baltic Sea Festival Science Lab. Drawing on insights from a joint reflection process, we recount our motivations for participation, provide insights on the co-production processes of six researcher-composer pairs, and share our experiences of the performances. We highlight openness to other ways of working, different perspectives and opinions, and emergence as well as collaborative skills, including listening, communication, and problem-solving skills, as key enablers for crossing disciplinary boundaries in art-science collaborations. As answers to the question on how, why, and in what ways platforms for dialogue can turn into platforms for learning, we discuss opportunities for designing safe-enough spaces, working towards a shared goal while embracing the unfolding nature of a process, and engaging in reflection to follow up on and make sense of one’s learning. Through this study, we hope to provide guidance for those who wish to engage in art-science collaborations to co-produce pathways towards sustainable futures together.

Palsa mires are located at the southern border of the permafrost region. Rising temperatures have led to widespread permafrost thaw and rapid palsa and peat plateau degradation. Palsa mires store significant amounts of carbon (C), which is released when permafrost thaws, potentially changing the peatlands from long-term C sinks to temporary C sources. To improve predictions of how palsa mires will respond to ongoing climate change, a better understanding of their past dynamics is vital. Here, we reconstruct the permafrost history of a peat plateau in Karlebotn, northern Norway, using a multiproxy approach. A peat profile was dated by accelerator mass spectrometry radiocarbon method, and analyzed for oribatid mite communities, peat type and peat properties. Oribatid mite analysis is a relatively novel method suggested as a proxy for permafrost initiation. Here, we compared it to more established approaches based on peat characteristics and vegetation changes. Our results suggest that gradual permafrost aggradation at the site began after ca. 1000 calibrated years Before Present (cal year BP; present = 1950 AD) with stable permafrost conditions established by ca. 400 cal year BP. Three peatland succession phases were identified: the first wet fen phase, a transitional phase with wet and dry condition taxa and the last phase dominated by species typical of dry and permafrost-associated conditions. Our results show that integrating oribatid mite analysis into paleoecological studies offers a more robust reconstruction of past permafrost dynamics, thereby enhancing our understanding of the past, present and future development of palsa mires.

ABSTRACT Whether evolution follows predictable genetic paths across species remains a central question in evolutionary biology, particularly as rising temperatures reshape species distributions worldwide. Despite its importance, the genetic basis of thermal adaptation remains poorly understood across divergent species. Here, we use the yeast genus Saccharomyces as a comparative model to investigate how species with contrasting thermal niches adapt to rising temperatures. We combined experimental evolution under progressively increasing temperatures for up to ∼600 generations with whole-genome sequencing of 256 evolved genotypes, followed by transcriptomic, functional, and physiological analyses across eight species. Despite large differences in ancestral thermal tolerance and evolutionary outcomes, selection repeatedly targeted the same conserved regulatory pathways across species. Independent lineages accumulated de novo mutations in central growth and stress response networks, particularly in TORC1, PKA, and MAPK signaling pathways, revealing striking molecular convergence across species occupying distinct thermal environments. However, these shared genetic targets produced divergent transcriptional and physiological responses depending on species background, indicating that thermal adaptation primarily proceeds through rewiring of conserved regulatory hubs rather than changes in temperature-specific enzymes. Cold-tolerant species frequently lost mitochondrial DNA during thermal evolution, yet loss alone was insufficient to reproduce the adaptive thermal phenotypes of evolved populations. Together, our results show that adaptation to increasing temperature is driven by predictable changes in conserved regulatory networks, while species-specific constraints shape divergent phenotypic outcomes. These findings reveal both the predictability and contingency of evolutionary responses to rising temperature across species.

Abstract. We present a fully implicit finite element method for viscous free surface Stokes problems which are common in glaciology and geodynamics. Standard fully implicit iterative solvers diverge for such problems when using large time steps. We address this by incorporating a stabilization term that vanishes upon convergence. This approach enables the use of large time steps, thereby significantly improving the efficiency of simulations. Furthermore, we leverage the fully implicit solver to develop second-order time-stepping schemes that mitigate the high errors associated with first-order methods for large time steps. The methods are tested and evaluated on model domains relevant to geodynamics and glaciology.