Recent results of laser spectroscopy experiments of pionic helium atoms at PSI

A review of a recent experiment carried out at PSI involving laser spectroscopy of metastable pionic helium (\pi{^4He}^+\equiv\pi^{-}+{^4He}^{2+}+e^-π4He+≡π−+4He2++e−) atoms is presented. An infrared transition (n,\ell)=(17,16)(n,ℓ)=(17,16)\rightarrow→(17,15)(17,15) at a resonance frequency of \nu\approx 183760ν≈183760 GHz was detected.

Superstatistical modelling of protein diffusion dynamics in bacteria

A recent experiment (Sadoon AA, Wang Y. 2018 Phys. Rev. E 98 , 042411. ( doi:10.1103/PhysRevE.98.042411 )) has revealed that nucleoid-associated proteins (i.e. DNA-binding proteins) exhibit highly heterogeneous diffusion processes in bacteria where not only the diffusion constant but also the anomalous diffusion exponent fluctuates for the various proteins. The distribution of displacements of such proteins is observed to take a q -Gaussian form, which decays as a power law. Here, a statistical model is developed for the diffusive motion of the proteins within the bacterium, based on a superstatistics with two variables. This model hierarchically takes into account the joint fluctuations of both the anomalous diffusion exponents and the diffusion constants. A fractional Brownian motion is discussed as a possible local model. Good agreement with the experimental data is obtained.

“Hit the Robot on the Head With This Mallet” – Making a Case for Including More Open Questions in HRI Research

Researchers continue to devise creative ways to explore the extent to which people perceive robots as social agents, as opposed to objects. One such approach involves asking participants to inflict ‘harm’ on a robot. Researchers are interested in the length of time between the experimenter issuing the instruction and the participant complying, and propose that relatively long periods of hesitation might reflect empathy for the robot, and perhaps even attribution of human-like qualities, such as agency and sentience. In a recent experiment, we adapted the so-called ‘hesitance to hit’ paradigm, in which participants were instructed to hit a humanoid robot on the head with a mallet. After standing up to do so (signaling intent to hit the robot), participants were stopped, and then took part in a semi-structured interview to probe their thoughts and feelings during the period of hesitation. Thematic analysis of the responses indicate that hesitation not only reflects perceived socialness, but also other factors including (but not limited to) concerns about cost, mallet disbelief, processing of the task instruction, and the influence of authority. The open-ended, free responses participants provided also offer rich insights into individual differences with regards to anthropomorphism, perceived power imbalances, and feelings of connection toward the robot. In addition to aiding understanding of this measurement technique and related topics regarding socialness attribution to robots, we argue that greater use of open questions can lead to exciting new research questions and interdisciplinary collaborations in the domain of social robotics.

Stability and superconductivity of Ca-intercalated bilayer blue phosphorene

Superconductivity attracts much interest in two-dimensional compounds due to their potential application in nano-superconducting devices. Inspired by a recent experiment reporting the superconducting state in twisted bilayer graphene, here, based...

Restoring Walking Complexity in Older Adults Through Arm-in-Arm Walking: Were Almurad et al.’s (2018) Results an Artifact?

The analysis of stride series revealed a loss of complexity in older people, which correlated with the falling propensity. A recent experiment evidenced an increase of walking complexity in older participants when they walked in close synchrony with a younger companion. Moreover, a prolonged experience of such synchronized walking yielded a persistent restoration of complexity. This result, however, was obtained with a unique healthy partner, and it could be related to a particular partner’s behavior. The authors’ aim was to replicate this important finding using a different healthy partner and to compare the results to those previously obtained. The authors successfully replicated the previous results: synchronization yielded an attraction of participants’ complexity toward that of their partner and a restoration of complexity that persisted in two posttests, 2 and 6 weeks after the end of the training sessions. This study shows that this complexity restoration protocol can be applied successfully with another partner, and allows us to conclude that it can be generalized.

The role of the three body photodissociation channel of water in the evolution of dioxygen in astrophysical applications

A recent experiment at the Dalian Coherent Light Source (DCLS) has provided measurements of the partial cross sections for the photodissociation of water vapor over an unprecedented range of wavelengths in the vacuum ultraviolet (VUV) region.

Prominent nonequilibrium effects beyond the standard first-principles approach in nanoscale electronic devices

The standard density functional theory (DFT) based first-principles approach has been widely used for modeling nanoscale electronic devices. A recent experiment, however, reported surprising transport properties of thiol-terminated silanes junctions...

Error Detection and Representational Mechanisms

This chapter defends a mechanistic and teleosemantic view of naturalized intentionality that underlies the role of error detection via coherence checking. Representational mechanisms serve the biological functions of representing, which are related to the semantic value of representation: its truth or falsity, its being vacuous or satisfied, or its accuracy. If representational mechanisms contain (or interact with) error-detection mechanisms, the semantic value of representation is causally relevant. As long as semantic value is causally relevant in cognitive explanations, the content of representation is arguably causally relevant, which vindicates the notion of mental representation in contemporary scientific research. Error detection is understood mechanistically in terms of coherence checking, which is purely computational and does not presuppose any semantic function. This chapter analyzes this conceptually and demonstrates that this account is descriptively adequate by citing a recent experiment on zebra finches, even though discrepancy detection is not always related to intentionality.

A competition of critics in human decision-making

Recent experiments and theories of human decision-making suggest positive and negative errors are processed and encoded differently by serotonin and dopamine, with serotonin possibly serving to oppose dopamine and protect against risky decisions. We introduce a temporal difference (TD) model of human decision-making to account for these features. Our model involves two opposing counsels, an optimistic learning system and a pessimistic learning system, whose predictions are integrated in time to control how potential decisions compete to be selected. Our model predicts that human decision-making can be decomposed along two dimensions: the degree to which the individual is sensitive to (1) risk and (2) uncertainty. In addition, we demonstrate that the model can learn about reward expectations and uncertainty, and provide information about reaction time despite not modeling these variables directly. Lastly, we simulate a recent experiment to show how updates of the two learning systems could relate to dopamine and serotonin transients, thereby providing a mathematical formalism to serotonin's hypothesized role as an opponent to dopamine. This new model should be useful for future experiments on human decision-making.

The Stories We Tell

Last week, I told you about my daughter Amanda's first experience with “hard math.” My guess is that the young people in your life have their own stories to share. No doubt they have struggled and failed at something important to them. Surely they have stories of success, too—perhaps, as it was for Amanda, following a dark period when self-efficacy was at a low point. If, as four decades of research have shown, self-efficacy grows with small wins, does anything turbocharge such learning? A recent experiment supported by Character Lab suggests that experience is an even better teacher when followed by writing. Students spent 15 to 20 minutes writing about a time they failed, and at least one way this failure changed them for the better, as well as a time they succeeded, and the steps they took to “make this success a reality.” Compared to a control group, the students who did this writing exercise demonstrated greater academic persistence, which in turn predicted better grades the following marking period.