University of Freiburg

CT perfusion (CTP) is widely used to assess infarct core in acute stroke, yet real-world data on its reproducibility and temporal dynamics are limited. We retrospectively identified patients with repeated CTP scans. Core and hypoperfusion volumes were quantified using standard thresholds (CBF <30 %, Tmax >6 s). Clinical and imaging data were reviewed to identify cases with disruptive events. We analyzed scan-to-scan differences in core volume, hypoperfusion volume, ASPECTS, and intensity metrics, including median Tmax (in hypoperfusion), CBF, and NCCT HU (in core), using Bland-Altman analysis and assessed their association with time between scans. Among 32 patients with repeated CTP (26 with repeated NCCT), three were excluded due to disruptive events. In the remaining 29 cases, mean scan-to-scan differences for infarct core volume (4.8 ± 19.6 mL), hypoperfusion volume (3.86 ± 39.1 mL), and ASPECTS (-0.4 ± 1.6) indicated minimal systematic bias at the group level but substantial variability. Correlation coefficients were high (r = 0.90, 0.93, and 0.70, respectively; all p < 0.0001), and no statistically significant paired differences or association with scan interval were observed. Intensity-based metrics likewise showed minimal bias with lower variability (Tmax -0.3 ± 1.07 s; CBF -3.11 ± 7.3 %; NCCT HU -3.0 ± 4.9 %), high correlations (Tmax r = 0.87, CBF r = 0.91, NCCT HU r = 0.69; all p < 0.02), and no association with time between scans. Repeated CTP showed no systematic group-level scan-to-scan bias suggestive of infarct growth, while a substantial degree of variability was observed, with intensity-based metrics demonstrating lower variability than volume estimates. These findings support temporal consistency of perfusion-derived metrics at the group level and question the applicability of linear infarct growth rate (IGR) concepts to perfusion imaging, which primarily reflects a hemodynamic state rather than time-dependent tissue progression.

Stress significantly influences eating behavior, yet individual responses vary. Binge eating - a core feature of Binge Eating Disorder and Bulimia Nervosa - is frequently triggered by acute stress. One proposed mechanism is that stress increases the motivational salience of food cues, which could promote craving and food intake. To test this idea experimentally, this study examined how stress affects attentional bias toward food, and how such changes relate to food craving and food intake in individuals with binge eating behaviors compared with individuals without binge eating. Using a mixed experimental design, 130 participants (68 with binge eating, 62 without binge eating) completed sessions with and without stress induction via a video-conference Trier Social Stress Test. Attentional bias was assessed via the Dot Probe Paradigm and eye tracking, food craving was measured via self-reports, and food intake was measured behaviorally. Stress did not significantly change attentional bias toward food, nor did it affect food intake. Stress did increase craving in the group with binge eating, indicating that stress enhanced the motivational value of food. The absence of corresponding changes in attentional bias suggests that heightened craving under stress does not necessarily translate into measurable shifts in attentional allocation toward food cues, or that stress may influence motivational processes without altering overt attentional patterns. Another possibility is that methodological restraints specific to our study design limited the detection of stress-related changes in attentional processes. Further research is needed to clarify the role of attentional processes in stress-related eating, especially regarding binge eating.

Post-disturbance recovery is a central element of forest resilience against intensifying disturbance regimes. Although recovery signals are strong across Central European forests, the relative roles of different factors contributing to recovery remain incompletely understood. As climate change increasingly challenges recovery, elucidating these processes is essential to adapt forest management to changing climate and disturbance regimes. We extended and applied a biologically grounded model of forest growth to remote sensing data to quantify how management shapes two key drivers of canopy recovery—disturbance legacies and post-disturbance height growth—across Bavaria, Germany. We combined 23,036 ha of quality-filtered photogrammetric canopy height model data with a Landsat-based disturbance map, a forest ownership map and environmental covariates in a Bayesian modelling framework. Post-disturbance growth rates were governed primarily by forest type and site conditions, whereas management strongly influenced disturbance legacies, i.e. the remaining post-disturbance vegetation height structure on site. Legacies varied widely across management types: Federal and set-aside forests retained the highest level of disturbance legacies, while private forests had the lowest legacy levels. Despite marginally lower growth rates, set-aside areas had recovery trajectories that were comparable to managed forests. The median recovery time to 5 m mean canopy height was 14.3 years over all forest and management types. Set-aside areas exhibited the greatest variation in recovery trajectories. We here show that (i) management affects disturbance legacies more strongly than post-disturbance tree growth, (ii) set-aside areas do not differ in recovery speed from managed areas, and (iii) legacies are diversifying forest recovery trajectories, with potential implications for future forest resilience. Our results underline that the post-disturbance reorganization window is a crucial period for management to influence long-term forest development. The framework presented here provides a scalable approach to monitor structural recovery and guide adaptive forest policy and management under increasing disturbance. • Forest management in Central Europe affects post-disturbance recovery more via legacies than tree growth rates. • Set-aside forests recover their canopy height equally fast as managed forests in Central Europe. • Homogenizing and removing disturbance legacies can reduce forest canopy variation across forest stand development. • We combined a biological growth model with remote sensing data to assess forest canopy recovery.

S-Adenosyl-l-methionine (SAM) is the second most used enzyme cofactor and vital for numerous cellular reactions such as methylation or polyamine synthesis. While most stereocentres of the biologically active (SS,SCα)-SAM are fixed, epimerisation at the methyl sulfonium centre is driven by heat, yielding biologically inactive (RS,SCα)-SAM. This SAM diastereomer disturbs SAM-dependent pathways, posing a metabolic threat, especially to thermophilic organisms. In vitro analysis shows that SAM hydrolases cleave the biologically inactive (RS,SCα)-SAM, thereby constituting a metabolic salvage pathway. To further assess the biological relevance of this pathway, we characterised two archaeal SAM hydrolases from the thermophilic Sulfolobus acidocaldarius and the halophilic Haloferax volcanii, confirming their selectivity towards (RS,SCα)-SAM in vitro. Genetic manipulation in the native hosts supports a significant role of the SAM hydrolases in decreasing the share of intracellular (RS,SCα)-SAM to sustain cellular functions in thermophilic organisms.

Many flying insects, such as bees, wasps, and hoverflies, live aboveground, but depend on soil for nesting, development, and overwintering. In agricultural landscapes, soil is managed for production and therefore frequently subjected to disturbances such as ploughing, potentially influencing flying insects during their belowground life stages. To investigate the effects of ploughing on ground-nesting flying insects, we conducted a two-year field experiment in twelve wildflower strips. All strips were ploughed and sown during establishment and were 0, 1, 2 or 3 years old at the start of the experiment. Within wildflower strips, we compared unploughed control plots with adjacent treatment plots that were ploughed between the two sampling years. This design allowed us to assess the ploughing effect across different ages and whether time since establishment influenced insects. We used emergence traps to sample insects emerging from the soil and measured insect biomass, abundance, and body size. We found that ploughing substantially reduced ground-nesting flying insect biomass. When wildflower strips were left unploughed, biomass increased rapidly, particularly during the first years after their establishment. Ploughing consistently reduced insect biomass to equally low levels regardless of how long the wildflower strips had been established. This was driven primarily by declines in the abundance of large insects. Our findings highlight that even moderate reductions in ploughing frequency - for example, only every second year - can benefit ground-nesting flying insects and point to the potential for incorporating reduced ploughing frequencies into agricultural management and agri-environmental schemes. • Ploughing reduced the biomass of ground-nesting insects in wildflower strips. • Biomass rose rapidly in unploughed sites, especially during the first years. • Biomass dropped to equally low levels after ploughing, regardless of recovery time. • Large insects were most affected by ploughing, causing biomass drops. • Reducing ploughing, even to every two years, enhances insect biomass.