University of Padua

The emergence of Automated Vehicles (AVs) will result in mixed traffic with Human-Driven Vehicles (HDVs), creating a complex traffic environment. While literature supports the effect of AVs on human driving behavior, the influence of different AV driving styles in this context remains largely unexplored. This study investigated interactions between HDVs and AVs varying in driving style (cautious vs. aggressive) and appearance (recognizable vs. unrecognizable) at Market Penetration Rates (MPR) of 0% to 75% in 25% increments within a highway context. Car-following behavior of 160 participants (56 females, age range 19-65) in a driving simulator experiment was analyzed using average time headway (THW) and standard deviation of relative speed (SDRS) as key metrics. Linear Mixed Models (LMMs) and Structural Equation Modelling (SEM) were applied. Results showed that compared to the baseline (no AVs), drivers' THW decreased when interacting with aggressive AVs by 11.1%, 8.6%, and 13.2% at MPRs of 25%, 50%, and 75%, respectively. Interactions with cautious AVs led to even larger reductions in THW by about 9.9%, 16.6%, and 17.3% at the same MPRs. SDRS improved across MPRs by 4.5%, 5.2%, and 6.2%, independent of AV driving style or appearance. SEM analysis indicated that AV driving style moderated relationships between independent, mediating, and dependent variables, while drivers' perceived stress and comfort mediated effects of AVs, trust propensity, and recognizability on THW and SDRS. These findings provide insights into human responses to AV behavior, highlighting implications for traffic flow and safety to ensure smoother and safer human-AV interactions.

Research on the role of the physical school environment in areas other than educational psychology has documented the benefits of exposure to nature for cognitive and emotional functioning. Positive effects have been indicated not only after a break in nature in mentally fatigued students but also in students who did not have depleted mental resources when performing cognitive tasks in a green area. We investigated the impact of the physical school environment during a single lesson. We also considered psychophysiological self-regulation as a possible moderator of the relationship between environment and learning. We used data from 101 sixth and seventh graders for self-reported variables. Data about psychophysiological self-regulation, measured as resting cardiac vagal tone, was available for 83 students. In a within-participants research design, we compared the effects of a lesson in the classroom and a lesson in a green urban park close to the school - featuring numerous trees of different sizes, with lush foliage - on participants' affective state, perception of the environmental quality, and conceptual learning. After the lesson in nature, students reported more positive affect and perceived the park as a higher quality environment compared with the indoor classroom. Students with higher cardiac vagal tone learned more in nature, whereas this individual characteristic did not play a role in the classroom environment. Passive exposure to nature during a school lesson has a positive affective impact and may also be beneficial for conceptual learning in combination with a higher ability to flexibly adapt to environmental demands.

The substitution of carboxylate donors with neutral amide groups is a well-established approach for tuning charge distribution and hydration properties in metal chelates; however, its influence on Fe(III) systems has remained largely unexplored. Here, we report two CDTA-derived ligands incorporating one or two secondary butylamide substituents (CD3A-BA and CD2A-BA₂) and comprehensively characterize their Fe(III) complexes using potentiometry, capillary zone electrophoresis, UV-Vis spectrophotometry, transchelation assays (with HBED and human serum transferrin), 1H NMRD, variable-temperature 17O NMR, and in vitro cytotoxicity tests. Amide incorporation decreases ligand basicity and leads to reduced complex stability and kinetic inertness compared to the parent CDTA framework. Nevertheless, the new Fe(III) complexes retain strong metal affinity and remain monohydrated under physiologically relevant conditions. Progressive amide substitution systematically slows inner-sphere water exchange, consistent with the higher residual positive charge of the complexes. Despite this, relaxivity in media mimicking physiological conditions remains unchanged, with negligible protein binding and no detectable Fe(III) release. Cellular assays confirm an absence of cytotoxicity at the tested concentrations. Collectively, these findings elucidate how secondary-amide substitution governs stability, reactivity, and hydration dynamics in Fe(III)-CDTA derivatives, offering valuable insights for the rational design of Fe(III)-based MRI contrast agents.