Objective:
In this article, we investigated the effects of external human-machine interfaces (eHMIs) on pedestrians’ crossing intentions.
Background:
Literature suggests that the safety (i.e., not ...crossing when unsafe) and efficiency (i.e., crossing when safe) of pedestrians’ interactions with automated vehicles could increase if automated vehicles display their intention via an eHMI.
Methods:
Twenty-eight participants experienced an urban road environment from a pedestrian’s perspective using a head-mounted display. The behavior of approaching vehicles (yielding, nonyielding), vehicle size (small, medium, large), eHMI type (1. baseline without eHMI, 2. front brake lights, 3. Knightrider animation, 4. smiley, 5. text WALK), and eHMI timing (early, intermediate, late) were varied. For yielding vehicles, the eHMI changed from a nonyielding to a yielding state, and for nonyielding vehicles, the eHMI remained in its nonyielding state. Participants continuously indicated whether they felt safe to cross using a handheld button, and “feel-safe” percentages were calculated.
Results:
For yielding vehicles, the feel-safe percentages were higher for the front brake lights, Knightrider, smiley, and text, as compared with baseline. For nonyielding vehicles, the feel-safe percentages were equivalent regardless of the presence or type of eHMI, but larger vehicles yielded lower feel-safe percentages. The Text eHMI appeared to require no learning, contrary to the three other eHMIs.
Conclusion:
An eHMI increases the efficiency of pedestrian-AV interactions, and a textual display is regarded as the least ambiguous.
Application:
This research supports the development of automated vehicles that communicate with other road users.
Objectives This study aimed to investigate and compare the anatomical features of the nasolacrimal drainage system (NDS) in three brachycephalic dog breeds with those of normocephalic dogs, taking ...into account how the NDS was related to the malformed brachycephalic head. Animals Fifty-one brachycephalic dogs were examined, comprising 23 Pugs, 18 French Bulldogs, and 10 English Bulldogs. Six normocephalic dogs of different breeds served as a comparison. Methods Computed tomographic dacryocystography was performed. Parameters such as length, angulation, and gradient were determined. Crossing of the nasolacrimal duct (NLD) beneath the maxillary canine root, as well as the incidence of an accessory opening, were also analyzed. Results and conclusions In all three brachycephalic breeds, the NDS was grossly malformed. We regard this as a further consequence of exaggerated breeding for a short head conformation. While the length of the NLD was substantially reduced by 41 to 57 percent in brachycephalic dogs, their lacrimal canaliculi were two to three times as long as those of normocephalic dogs. Varying parts of the nasolacrimal drainage system followed an inverse direction in short-headed dogs, giving the entire nasolacrimal apparatus an anomalous U- or V-shaped appearance. The NLD exhibited a three to five times steeper alignment in brachycephalic dogs than in normocephalic ones. Obviously, this strong slope did not cause clinical symptoms only because there was an aberrant outflow pathway. The brachycephalic dogs consistently exhibited an accessory opening, through which most of fluid escaped into the posterior nasal cavity instead of through the common route into the nasal vestibule via the nasolacrimal ostia.
Plant mitochondria have a complex and peculiar genetic system. They have the largest genomes, as compared to organelles from other eukaryotic organisms. These can expand tremendously in some species, ...reaching the megabase range. Nevertheless, whichever the size, the gene content remains modest and restricted to a few polypeptides required for the biogenesis of the oxidative phosphorylation chain complexes, ribosomal proteins, transfer RNAs and ribosomal RNAs. The presence of autonomous plasmids of essentially unknown function further enhances the level of complexity. The physical organization of the plant mitochondrial DNA includes a set of sub-genomic forms resulting from homologous recombination between repeats, with a mixture of linear, circular and branched structures. This material is compacted into membrane-bound nucleoids, which are the inheritance units but also the centers of genome maintenance and expression. Recombination appears to be an essential characteristic of plant mitochondrial genetic processes, both in shaping and maintaining the genome. Under nuclear surveillance, recombination is also the basis for the generation of new mitotypes and is involved in the evolution of the mitochondrial DNA. In line with, or as a consequence of its complex physical organization, replication of the plant mitochondrial DNA is likely to occur through multiple mechanisms, potentially involving recombination processes. We give here a synthetic view of these aspects.
Group II introns are large catalytic RNAs that are ancestrally related to nuclear spliceosomal introns. Sequences corresponding to group II RNAs are found in many prokaryotes and are particularly ...prevalent within plants organellar genomes. Proteins encoded within the introns themselves (maturases) facilitate the splicing of their own host pre-RNAs. Mitochondrial introns in plants have diverged considerably in sequence and have lost their maturases. In angiosperms, only a single maturase has been retained in the mitochondrial DNA: the matR gene found within NADH dehydrogenase 1 (nad1) intron 4. Its conservation across land plants and RNA editing events, which restore conserved amino acids, indicates that matR encodes a functional protein. However, the biological role of MatR remains unclear. Here, we performed an in vivo investigation of the roles of MatR in Brassicaceae. Directed knockdown of matR expression via synthetically designed ribozymes altered the processing of various introns, including nad1 i4. Pull-down experiments further indicated that MatR is associated with nad1 i4 and several other intron-containing pre-mRNAs. MatR may thus represent an intermediate link in the gradual evolutionary transition from the intron-specific maturases in bacteria into their versatile spliceosomal descendants in the nucleus. The similarity between maturases and the core spliceosomal Prp8 protein further supports this intriguing theory.
During online learning, it is essential to provide instructional guidance to support learning. However, guidance can be given in different forms and quantities. Thus, one important challenge is to ...provide the right amount and type of instructional guidance.
The aim of the study is to investigate types of guidance which are effective for students with heterogenous programming knowledge and skills solving programming tasks in a remote laboratory.
We carried out two studies with a single factor pre-post-design with guidance (basic/enhanced) as a between-subjects factor.
In study 1, we implemented enhanced guidance in the form of prompts in the introduction to the tasks. Whereas we found no differences in learning outcome or extraneous cognitive load, students in the enhanced guidance group reported less intrinsic motivation, and logfiles revealed a lower programming performance. In study 2, we implemented enhanced guidance in the form of adaptive just-in-time explanations for error streaks. Enhanced guidance led to a lower extraneous cognitive load, and this way increased learning outcome.
The type and timing of instructional guidance for students in computer science matters. More guidance is not better in each case. Instructional guidance should be tailored to students' needs.
Both endogenous processes and exogenous physical and chemical sources generate deoxyribonucleic acid (DNA) damage in the nucleus and organelles of living cells. To prevent deleterious effects, damage ...is balanced by repair pathways. DNA repair was first documented for the nuclear compartment but evidence was subsequently extended to the organelles. Mitochondria and chloroplasts possess their own repair processes. These share a number of factors with the nucleus but also rely on original mechanisms. Base excision repair remains the best characterized. Repair is organized with the other DNA metabolism pathways in the organelle membrane-associated nucleoids. DNA repair in mitochondria is a regulated, stress-responsive process. Organelle genomes do not encode DNA repair enzymes and translocation of nuclear-encoded repair proteins from the cytosol seems to be a major control mechanism. Finally, changes in the fidelity and efficiency of mitochondrial DNA repair are likely to be involved in DNA damage accumulation, disease and aging. The present review successively addresses these different issues.
► Endogenous and exogenous sources generate organelle DNA damage. ► Mitochondria and chloroplasts possess specific DNA repair pathways. ► Functional DNA repair in organelles is associated with the membrane compartment. ► Mitochondrial DNA repair is impaired in disease and aging. ► Regulation of organelle DNA repair may rely on relocalization of repair proteins.
Abstract
Mutations in the small genome present in mitochondria often result in severe pathologies. Different genetic strategies have been explored, aiming to contribute to rescue such mutations. A ...number of these were based on the capacity of human mitochondria to import RNAs from the cytosol and were designed to repress the replication of the mutated genomes or to provide the organelles with wild-type versions of mutant transcripts. However, the mutant RNAs present in mitochondria turned out to be an obstacle to therapy and little attention has been devoted so far to their elimination. Here, we present the development of a strategy to knockdown mitochondrial RNAs in human cells using the transfer RNA-like structure of the Brome mosaic virus or the Tobacco mosaic virus as a shuttle to drive trans-cleaving ribozymes into the organelles in human cell lines. We obtained a specific knockdown of the targeted mitochondrial ATP6 mRNA, followed by a deep drop in ATP6 protein and a functional impairment of the oxidative phosphorylation chain. Our strategy opens a powerful approach to eliminate mutant organellar transcripts and to analyze the control and communication of the human organellar genetic system.
•Participants’ risk avoiding behaviors are sensitive to cultural difference in this study.•Chinese participants maintain a higher speed in the stated scenario.•Chinese participants have a longer ...reaction time than German participants in the stated scenario.
Driving simulators are useful tools for traffic safety researches as they can create repeatable scenarios that cannot be easily created in real world. The present study investigated whether there existed significant differences in risk-avoiding behaviors between Chinese and German young male student drivers when interacting with vulnerable traffic participants. Twenty Chinese and twenty-one German young male drivers were recruited to perform a series of simulated driving including three scenarios of traffic conflict: (1) motorbike lane violation (2) pedestrian crossing urban street (3) Animal (wild boar) crossing highway road. A questionnaire-based survey about subjective assessment of the severity of the conflicts was conducted after experiment. Using data collected from the driving simulator and questionnaire, differences in risk-avoiding behaviors between two groups of drivers were tested. Results showed that Chinese young male drivers would maintain a higher speed in scenario (1), they also had a higher score of severity of conflicts in scenario (1) and (3). German young male drivers had a shorter reaction time under the same time-to-collision (TTC) in scenario (3), and they had a shorter reaction time in the case of a longer time-to-collision (TTC) in scenario (1).
Mitochondria of flowering plants have large genomes whose structure and segregation are modulated by recombination activities. The post-synaptic late steps of mitochondrial DNA (mtDNA) recombination ...are still poorly characterized. Here we show that RADA, a plant ortholog of bacterial RadA/Sms, is an organellar protein that drives the major branch-migration pathway of plant mitochondria. While RadA/Sms is dispensable in bacteria, RADA-deficient Arabidopsis plants are severely impacted in their development and fertility, correlating with increased mtDNA recombination across intermediate-size repeats and accumulation of recombination-generated mitochondrial subgenomes. The radA mutation is epistatic to recG1 that affects the additional branch migration activity. In contrast, the double mutation radA recA3 is lethal, underlining the importance of an alternative RECA3-dependent pathway. The physical interaction of RADA with RECA2 but not with RECA3 further indicated that RADA is required for the processing of recombination intermediates in the RECA2-depedent recombination pathway of plant mitochondria. Although RADA is dually targeted to mitochondria and chloroplasts we found little to no effects of the radA mutation on the stability of the plastidial genome. Finally, we found that the deficient maintenance of the mtDNA in radA apparently triggers a retrograde signal that activates nuclear genes repressing cell cycle progression.
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