Landslides triggered by degrading mountain permafrost pose an increasing risk to life and infrastructure in mountain regions due to current climate change trends. Because discontinous mountain ...permafrost is not directly detectable by remote sensing, permafrost molards offer a way of indirectly detecting its location and state. Permafrost molards are cones of loose debris that are associated with landslide deposits. They originate from ice-cemented blocks of sediment that are transported downslope with the landslide. These ice-cemented blocks are fragmented parts of the permafrost initially located in the landslide source area. Over time, these blocks degrade into conical mounds with diameters typically ranging from decimeters up to 40 m. They indicate the presence of an area of degrading permafrost at the level of the detachment zone. The physical processes that lead to the formation of molards from the ice-cemented blocks have not yet been studied in detail. Therefore, we perform an experimental study to recreate molards in a controlled laboratory environment and investigate the key formation processes. We downscale the molards to an initial cube side length of ~30 cm, and reduced the model's complexity by using two different types of gravel with a defined granulometry and lithology. We quantified the degradation phase by using a novel photogrammetric time-lapse system to detect changes in the digital elevation model between half-hourly time-steps. For the first time, we successfully recreated morphologies resembling molards under controlled laboratory conditions on a decimeter scale. We find the main processes to produce the final molard shape are cascades of grainfall for slightly cohesive sediment, and individual grainfall for non-cohesive sediment. Our experiments reveal three possible cross-section shapes (bell-shaped, triangular, trapezoidal) that correspond to molards that can be found in the field. Along with these field observations, we suggest that it may be possible to identify the cohesion of a molard's sediment based on its morphology. Together with future field data and experiments investigating the granulometry, ice and clay contents of the initial ice-cemented block, we aim to use molards as a record to better understand the landslide dynamics and state of the mountain permafrost.
•Successful reproduction of permafrost molard morphology in a controlled laboratory environment.•Determination of the most important processes in the formation of permafrost molards using time-lapse photogrammetry.•The flank angles of molards in the laboratory are up to 10 % steeper than the angle of repose of the respective material.•The cohesion of the molard material determines the molard's morphology and cross-section type.
Extreme environmental conditions, such as high and low salinity, are stressors for marine fish growth. Juveniles of marbled flounder Pseudopleuronectes yokohamae and stone flounder Platichthys ...bicoloratus use estuaries as nursery grounds. Our field surveys showed that the occurrence of juvenile stone flounder seemed to be unrelated to salinity, whereas that of juvenile marbled flounder was positively correlated with salinity. To examine the effects of salinity on feeding and growth of these species, we conducted a laboratory experiment in which juveniles were reared individually under constant and variable salinity regimes for seven days. Cultured marbled flounder of two sizes (23–29 and 48–58 mm standard length) were reared under constant salinities of 5, 15, and 30 and fluctuating salinities of 5–30 and 15–30 or 5–15. Wild stone flounder (23–37 mm standard length) were reared under constant salinities of 1, 5, and 30 and fluctuating salinities of 5–30 and 1–30. Commercial pellets were fed to fish twice daily until satiation. The feeding and growth of marbled and stone flounders were considerably low at constant salinities of 5 and 1, respectively. Meanwhile, suppression of feeding and growth was not observed in fish with salinities varying from 5 to 30 or 1 to 30, respectively. The results indicated that extremely low salinity inhibits feeding and growth of juveniles only with continuous exposure. Estuaries with fluctuating salinities are potential nursery grounds for both marbled flounder and stone flounder, although marbled flounder tend to avoid low-salinity environments in the field. This study showed that extremely low-salinity environments, which reduce juvenile growth when consistently exposed, would not affect distribution or growth if they were temporary around low tide.
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•Juvenile stone flounder occurred at wider salinity ranges than marbled flounder.•Feeding and growth of juveniles were reduced under extremely low salinities.•Juvenile growth inhibition did not occur at fluctuating salinity treatments.•Temporary low salinity environment does not hinder habitat use of juveniles.
This paper experimentally investigates risk taking in contest schemes by implementing a stopping task based on Seel and Strack (2013). In this stylized setting, managers with contest payoffs have an ...incentive to delay halting projects with a negative expectation, with the induced inefficiency being highest for a moderately negative drift. The experiment systematically varies the negative drift (between-subjects) and the payoff incentives (within-subject). We find evidence for risk taking in all our treatment conditions, with the non-monotonicity at least as pronounced as predicted. Contrary to the theoretical predictions, a similar pattern of behaviour persists even without contest incentives, suggesting contest incentives are not the only driver of risk-taking behaviour. Instead, observed behaviour violates expected utility maximization and is consistent with some intrinsic motivation for taking risk and myopic reasoning about the opponent. We explore the interplay between intrinsic incentives and the payment scheme and find that contest incentives might crowd out an intrinsic inclination to risk-taking.
This study addresses the emergence of (unarmed) peace and investments in arms within a guns-vs-butter conflict setting. We introduce a novel feature within the conflict game and separate the decision ...to start a conflict and the investment in arms, following the theoretical framework of Garfinkel and Syropoulos (2021). Based on this model we experimentally examine the emergence of peace while varying resource inequality among conflicting parties. We find that inequality leads to more conflicts and higher investments in arms. Despite these trends, achieving a state of unarmed peace is rarely observed in both treatments. Our results highlight the critical role of trust in attaining peaceful outcomes and show that armed peace, although not an optimal strategy in either treatment, is one of the most frequently chosen decisions.
•We investigate conflict and arming decisions in a novel guns-vs-butter setting.•We test the effect of resource inequality on decisions toward and in conflicts.•Inequality leads to more conflicts and higher investments in arms.•A state of unarmed peace is rarely observed, while armed peace occurs frequently.•Trust is identified as a key factor influencing decisions.
Carpooling is one of the travel demand management strategies to mitigate road congestion. Incentive-Based Travel Demand Management (IBTDM) strategies are pivotal for carpool promotion by providing ...incentives to address inconveniences and privacy apprehensions, yet their efficacy lacks validation. Considering the constraints of incentive budget as well as the penetration rate, it is important to assess the long-term impact of incentives on carpooling, improve the programs in term of information feedback and identify the individuals who are most inclined to carpool. To achieve the goals, we conducted a laboratory experiment through WeChat applet platform focused on carpooling and departure time choices. 194 participants successfully completed the entire experiment. The experiment emphasizes several crucial elements, including long term (participants making daily travel choices in one month), the interactivity and information feedback mechanisms, instruments enhancing participant engagement (redeeming incentives at the end of the experiment, etc.), exit questionnaire to collect travelers' behavioral strategies. The findings elucidate several key insights: 1) Incentives have a significant long-term influence on encouraging travelers to carpool, and compensatory mechanisms for unsuccessful carpool matches further amplify travelers' impetus. 2) IBTDM administrations can promote carpooling by improving feedback information according to travelers' learning effect in each round, such as introducing real-time displays of the numbers of carpool drivers and passengers. 3) Drawing from the analysis of travelers’ participation, behavioral compliance and psychological strategies of carpooling, it can be inferred that individuals with higher incomes, fewer commuting days who have a solid grasp of the experimental mechanism, constitute prospective candidates for carpooling programs. This work contributes to helping IBTDM administrations clarify the target participants and develop a more reasonable carpooling program. The behavioral data collection approach based on our laboratory experiment is portable for future studies.
•An interactive long-term laboratory experiment was conducted by WeChat applet.•Incentives have a significant long-term impact on promoting carpool.•Participants' information-based learning effects affect their travel behaviors.•Young, high-income travelers with good experimental understanding tend to carpool with incentives.•Low-income travelers with private cars tend to adjust departure times with incentives.
For the proper understanding and modelling of pedestrian dynamics, reliable empirical data are necessary for analysis and verification. To this end, we have performed a series of experiments with a ...large number of persons. Such experiments give us the opportunity to selectively analyse parameters independent of undesired influences and adjust them to values seldom seen in field studies.
We are developing software for the time-efficient automatic extraction of accurate pedestrian trajectories. Depending on the camera system the software is able to detect and track people on planar or uneven terrain with or without markers.
In this paper, we summarise the experiments we have accomplished and the possibilities of our extraction techniques, in particular the newly introduced algorithm of markerless detection in stereo recordings. The markerless detection based on groups of ellipses approximating isolines of the same distance to an overhead stereo camera.
Even though women׳s position in academia has changed dramatically over the last few decades, there is still some evidence that when it comes to evaluation of scientific achievements, gender may play ...a significant role. Gender bias is particularly likely to take the form of statistical discrimination. In this study we sought to verify the hypothesis that researcher׳s gender affects evaluation of his or her work, especially in a field where women only represent a minority. Towards this end we asked a sample of subjects, mostly economics majors, to evaluate a paper written by mixed-gender couples, indicating that it was (co-)authored by a “female economist”, “male economist”, “young female economist” or “young male economist” or giving no information about the author at all. While age factor played no role, female authors appeared to be seen as less competent than males, in that subjects (being incentivized to give their best judgment) less often believed that their papers have been published. This effect did not interact strongly with the gender of the subject.
The ability to predict when societies will replace one social norm for another can have significant implications for welfare, especially when norms are detrimental. A popular theory poses that the ...pressure to conform to social norms creates tipping thresholds which, once passed, propel societies toward an alternative state. Predicting when societies will reach a tipping threshold, however, has been a major challenge because of the lack of experimental data for evaluating competing models. We present evidence from a large-scale laboratory experiment designed to test the theoretical predictions of a threshold model for social tipping and norm change. In our setting, societal preferences change gradually, forcing individuals to weigh the benefit from deviating from the norm against the cost from not conforming to the behavior of others. We show that the model correctly predicts in 96% of instances when a society will succeed or fail to abandon a detrimental norm. Strikingly, we observe widespread persistence of detrimental norms even when individuals determine the cost for nonconformity themselves as they set the latter too high. Interventions that facilitate a common understanding of the benefits from change help most societies abandon detrimental norms. We also show that instigators of change tend to be more risk tolerant and to dislike conformity more. Our findings demonstrate the value of threshold models for understanding social tipping in a broad range of social settings and for designing policies to promote welfare.
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