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  1. Free, publicly-accessible full text available August 31, 2024
  2. Free, publicly-accessible full text available September 1, 2024
  3. ABSTRACT

    The line widths of broad-line regions (BLRs) of active galactic nuclei (AGNs) are key parameters for understanding central supermassive black holes. However, owing to obscuration from dusty tori, optical recombination lines from BLRs in type II AGNs cannot be directly detected. Radio recombination lines (RRLs), with low extinction, could be ideal tracers to probe the emission from BLRs in type II AGNs. We performed RRL observations for H35α and H36α towards the centre of the Circinus galaxy with Atacama Large Millimeter/submillimeter Array (ALMA). The narrow components of H35α and H36α, which are thought to be mainly from star-forming regions around the nuclear region, are detected. However, only upper limits are obtained for broad H35α and H36α. Because Circinus is one of the nearest AGNs, the non-detection of broad RRLs in Circinus in this band tells us that it is hopeless to try to detect broad RRL emission in local AGNs with current facilities. Submillimetre RRLs, with flux densities that are dozens of times higher than those at the millimetre level, could be the tools to directly detect BLRs in type II AGNs with ALMA, once its backend frequency coverage has been upgraded to several times better than its current capabilities.

     
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  4. Objective

    This study explores subjective and objective driving style similarity to identify how similarity can be used to develop driver-compatible vehicle automation.

    Background

    Similarity in the ways that interaction partners perform tasks can be measured subjectively, through questionnaires, or objectively by characterizing each agent’s actions. Although subjective measures have advantages in prediction, objective measures are more useful when operationalizing interventions based on these measures. Showing how objective and subjective similarity are related is therefore prudent for aligning future machine performance with human preferences.

    Methods

    A driving simulator study was conducted with stop-and-go scenarios. Participants experienced conservative, moderate, and aggressive automated driving styles and rated the similarity between their own driving style and that of the automation. Objective similarity between the manual and automated driving speed profiles was calculated using three distance measures: dynamic time warping, Euclidean distance, and time alignment measure. Linear mixed effects models were used to examine how different components of the stopping profile and the three objective similarity measures predicted subjective similarity.

    Results

    Objective similarity using Euclidean distance best predicted subjective similarity. However, this was only observed for participants’ approach to the intersection and not their departure.

    Conclusion

    Developing driving styles that drivers perceive to be similar to their own is an important step toward driver-compatible automation. In determining what constitutes similarity, it is important to (a) use measures that reflect the driver’s perception of similarity, and (b) understand what elements of the driving style govern subjective similarity.

     
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  5. Abstract

    The heart is capable of activating protective mechanisms in response to ischemic injury to support myocardial survival and performance. These mechanisms have been recognized primarily in the ischemic heart, involving paracrine signaling processes. Here, we report a distant cardioprotective mechanism involving hepatic cell mobilization to the ischemic myocardium in response to experimental myocardial ischemia–reperfusion (MI-R) injury. A parabiotic mouse model was generated by surgical skin-union of two mice and used to induce bilateral MI-R injury with unilateral hepatectomy, establishing concurrent gain- and loss-of-hepatic cell mobilization conditions. Hepatic cells, identified based on the cell-specific expression of enhanced YFP, were found in the ischemic myocardium of parabiotic mice with intact liver (0.2 ± 0.1%, 1.1 ± 0.3%, 2.7 ± 0.6, and 0.7 ± 0.4% at 1, 3, 5, and 10 days, respectively, in reference to the total cell nuclei), but not significantly in the ischemic myocardium of parabiotic mice with hepatectomy (0 ± 0%, 0.1 ± 0.1%, 0.3 ± 0.2%, and 0.08 ± 0.08% at the same time points). The mobilized hepatic cells were able to express and release trefoil factor 3 (TFF3), a protein mitigating MI-R injury as demonstrated in TFF3−/−mice (myocardium infarcts 17.6 ± 2.3%, 20.7 ± 2.6%, and 15.3 ± 3.8% at 1, 5, and 10 days, respectively) in reference to wildtype mice (11.7 ± 1.9%, 13.8 ± 2.3%, and 11.0 ± 1.8% at the same time points). These observations suggest that MI-R injury can induce hepatic cell mobilization to support myocardial survival by releasing TFF3.

     
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