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Chorus waves are naturally occurring electromagnetic emissions in space and are known to produce highly energetic electrons in the hazardous radiation belt. The characteristic feature of chorus is its fast frequency chirping, whose mechanism remains a long-standing problem. While many theories agree on its nonlinear nature, they differ on whether or how the background magnetic field inhomogeneity plays a key role. Here, using observations of chorus at Mars and Earth, we report direct evidence showing that the chorus chirping rate is consistently related to the background magnetic field inhomogeneity, despite orders of magnitude difference in a key parameter quantifying the inhomogeneity at the two planets. Our results show an extreme test of a recently proposed chorus generation model and confirm the connection between the chirping rate and magnetic field inhomogeneity, opening the door to controlled plasma wave excitation in the laboratory and space.

The Martian crustal magnetic anomalies present a varied, asymmetric obstacle to the imposing draped interplanetary magnetic field (IMF) and solar wind plasma. Magnetic reconnection, a ubiquitous plasma phenomenon responsible for transferring energy and changing magnetic field topology, has been observed throughout the Martian magnetosphere. More specifically, reconnection can occur as a result of the interaction between crustal fields and the IMF, however, the global implications and changes to the overall magnetospheric structure of Mars have yet to be fully understood. Here, we present an analysis to determine these global implications by investigating external conditions that favor reconnection with the underlying crustal anomalies at Mars. To do so, we plot a map of the crustal anomalies strength and orientation compiled from magnetic field data collected throughout the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission. Then, we create shear maps which calculate and plot the angle of shear between the crustal fields and a chosen external field orientation. From there we define a shear index to quantify the susceptibility of a region to undergo reconnection based on a given overlaid, external field orientation and the resulting shear map for that region. We demonstrate that the shear analysis technique augments analysis of local reconnection events and suggests southward IMF conditions should favor dayside magnetic reconnection on a more global scale at Mars.

The Martian magnetotail exhibits a highly twisted configuration, shifting in response to changes in polarity of the interplanetary magnetic fields (IMF) dawn-dusk (B Y) component. Here, we analyze ∼6000 MAVEN orbits to quantify the degree of magnetotail twisting (θ Twist) and assess variations as a function of (a) strong planetary crustal field location, (b) Mars season, and (c) downtail distance. The results demonstrate that θ Twist is larger for a duskward (+B Y) IMF orientation a majority of the time. This preference is likely due to the local orientation of crustal magnetic fields across the surface of Mars, where a +B Y IMF orientation presents ideal conditions for magnetic reconnection to occur. Additionally, we observe an increase in θ Twist with downtail distance, similar to Earths magnetotail. These findings suggest that coupling between the IMF and moderate-to-weak crustal field regions may play a major role in determining the magnetospheric structure at Mars.

The refilling of the lunar wake is facilitated by the wake ambipolar electric potential arising from the electron pressure gradient. Incident solar wind protons can be reflected by the lunar crustal magnetic fields and the lunar surface on the dayside and repicked up, entering the lunar wake due to their large gyroradii. This burst of positive charges can cause the lunar wake potential to be reduced by hundreds of volts. We utilize over 7 years of ARTEMIS (Acceleration, Reconnection, Turbulence, and Electrodynamics of the Moons Interaction with the Sun) measurements to systematically investigate how the reflected protons affect the lunar wake potential structure when the Moon is immersed in the solar wind. RPs have a peak occurrence rate of ~20% for downstream distances from the Moon at N × 2πR g and a preference of high occurrence rates and high densities in the direction of the motional electric field of the solar wind. We show that reflected protons in the lunar wake can significantly change the electrostatic ambipolar potentials in the wake, leading in turn to the formation of field-aligned, accelerated electron beams. Our case study also suggests a nonmonotonic field-aligned potential structure in the presence of reflected protons in the wake. Lastly, our results show that when the reflected proton density is larger than ~30% of the local proton density from refilling solar wind protons, the wake potential scales as the logarithmic density of reflected protons, which can be explained by the Boltzmann relation.

The joint Simon effect refers to inhibitory responses to spatially competing stimuli during a complementary task. This effect has been considered to be influenced by the social factors of a partner: sharing stimulus-action representation. According to this account, virtual interactions through their avatars would produce the joint Simon effect even when the partner did not physically exist in the same space because the avatars are intentional agents. To investigate this, we conducted two joint experiments in which participants controlled avatars as their agents in immersive virtual environments. In Experiment 1, participants were asked to touch a virtual button through their avatars when a target color of an object was presented. The target position was manipulated to be compatible with the button (compatible stimulus) or incompatible with the button (incompatible stimulus). In Experiment 2, the task was identical to that in Experiment 1 except that participants' gaze position was either visualized or not during the task. We hypothesized that visualizing the partner's gaze would enhance the joint Simon effect because gaze is a cue to mentalize others' internal states. The results showed that avatar-based interactions more significantly delayed responses for the incompatible than for the compatible stimulus. However, inconsistent with our hypothesis, visualizing the partner's gaze position did not influence responses for spatially competing stimuli. These results suggest that virtual interactions through avatar agents can produce the joint Simon effect even when the partner does not physically exist in the same space. [ABSTRACT FROM AUTHOR]

In this study, we introduce RecombiCraft, an innovative, rapid, and cost-efficient method for constructing DNA libraries in E. coli. This method uses seamless ligation cloning extract (SLiCE) coupled with liquid culture amplification to effectively minimize sequence biases. The technique capitalizes on the natural homologous recombination capabilities of E. coli cell lysates, eliminating the need for multiple purified enzymes and reducing costs. We first synthesized the library backbone and inserts via PCR, employing high-fidelity polymerase to minimize sequence bias. The SLiCE technique was then used to assemble the DNA fragments introduced into E. coli through electroporation. To ensure the integrity of the library, we optimized culture times based on next-generation sequencing analysis which confirmed the minimal sequence bias. The RecombiCraft method demonstrates that this approach is economical and maintains the library's uniformity. By using liquid culture, this method can complete DNA library generation in about 12 hours and final extraction is simple, making it a promising tool for genetic research and biotechnology applications. [ABSTRACT FROM AUTHOR]

Although meeting close friends through video calls has become common, less is known about its stress-buffering effect. This study aims to examine whether cardiovascular responses to stress are decreased when the presence of a friend on a monitor compared to the presence of a friend in person or alone. Forty-six undergraduate students completed a stress task while in the room with a friend (1) in person (in-person condition), (2) on Zoom (online condition), or (3) alone (alone condition). Blood pressure and heart rate were monitored throughout the experiment. Analyses revealed that diastolic blood pressure after the stress was recovered closer to the pre-stress state under in-person and online conditions than alone condition. However, the study observed no differences across groups regarding self-reported affect. In summary, this result suggests that even the online presence of a friend, as well as in-person friends, may help recover blood pressure to the original state without one's awareness. [ABSTRACT FROM AUTHOR]

To investigate the excitation mechanism of ionospheric perturbations on Mars by the Neutral Gas and Ion Mass Spectrometer (NGIMS) onboard Mars Atmosphere and Volatile EvolutioN (MAVEN), we categorize ionospheric perturbations into three cases: (a) the ion‐neutral coupling cases where ion and neutral perturbations are well coupled, (b) the ion‐specific cases where ion perturbations move independently from neutrals, and (c) the coronal mass ejection cases associated with solar wind extreme events. A representative number of cases from total profiles are compared with a numerical model to determine the fraction that can be explained by an atmospheric gravity waves (GW). The neutral perturbations on the dayside at 170–190 km altitudes are in excellent agreement with the GW. Whereas, contrary to previous thoughts, neutral perturbations are not necessarily explained by the GW especially on the nightside at 190–210 km. Ion perturbations on the dayside at 170–190 km also show a good agreement with the GW. The agreement becomes extremely low on the nightside at 190–210 km, reaching the limit of strong ion‐neutral coupling around 190 km. Further investigation found that the behavior of the ion perturbations explicitly depends on the dayside and nightside. Its dominant driver potentially differs clearly between dayside and nightside. Statistics of relative perturbations demonstrate a clear effect associated with species scale height in neutrals. Whereas, the correlation between ions and neutrals breaks down at high solar zenith angle near southern dusk. We see currently unexplained behavior that cannot be fully interpreted by GW both at night and near southern dusk. Plain Language Summary: In the upper atmosphere of Mars, both neutral and ionized atmospheres show large amplitude density disturbances that are not seen on Earth. The cause of these disturbances is still unknown; whether they are caused by atmospheric gravity waves (GW) propagating upward from the lower atmosphere or by plasma flows from the sun from space (solar wind; SW) has not yet been determined. We investigated the excitation mechanism of ion perturbations on Mars using the Neutral Gas and Ion Mass Spectrometer onboard NASA's Mars Atmospheric Variability Observatory satellite. We found that on the dayside, neutral atmospheric disturbances are well explained by atmospheric waves. Whereas, contrary to previous ideas, the neutral perturbations cannot always be explained by GW, especially on the night side. The difference in the behavior of ion perturbations between day and night is even more pronounced. While most of the perturbations on the dayside at lower altitudes could be explained by GW, most of the perturbations on the nightside at higher altitudes could not be explained by GW. Our results indicate that the drivers of ionospheric perturbations are potentially different on the day and the night sides. Key Points: We investigated the ionospheric perturbations on MarsThe fraction that can be explained by atmospheric gravity waves differs between day and night sidesWe see unexplained behavior both at night, and southern dusk [ABSTRACT FROM AUTHOR]

Recent studies have proposed that the automatic activation of naïve concepts, which persist even after learning scientific concepts, must be inhibited to successfully output scientific concepts. This model assumes that individual differences in inhibitory control (IC) within executive functions represent differences in conceptual change. However, the reported correlations between concept conflict and IC tasks are weak, casting doubt on this assumption. This study improves on previous methodologies by focusing on the performance of adult subjects in living and nonliving concept tasks presumed to have successfully achieved conceptual change and quantifying semantic‐level IC through the Stroop interference effect. The results revealed that the correlations between the Stroop interference effect and reaction time (RT) differences between conditions of the concept conflict task, which are assumed to represent the time required to inhibit naïve concepts, were relatively stronger compared with findings reported in previous studies. These findings suggest that individual differences in fluent inhibition of naïve concepts after acquiring scientific concepts align with those in IC, thereby supporting the validity of the inhibition model of naïve concepts. Even after learning a scientific concept (e.g., plants are alive), a previously held naïve concept (e.g., moving objects are alive) remains in a person's brain. This study investigated the characteristics of individuals who can successfully and fluently "suppress" naïve concepts in their brains when required to answer questions about scientific concepts. The results suggested a stronger connection than previously known with the well‐known cognitive ability of inhibitory control. [ABSTRACT FROM AUTHOR]

Mars lacks a global intrinsic dipole field but possesses localized crustal fields, making it unique in the solar system. Recent observations revealed that electrons can be injected into the crustal fields, and exhibit drift-dispersed bursts due to the magnetic drift motion, which are characterized by increases or decreases in energy over time in the energy spectrum. However, the source of the drift-dispersed electrons and the mechanism of their injection into the crustal fields remains unclear. Here, by leveraging data from the Mars Atmosphere and Volatile EvolutioN mission, along with test-particle simulations, we reveal that the source of dispersed electrons is the precipitating electrons injected into the crustal fields via open field lines. These electrons display as dispersionless bursts near the source location, and as dispersed bursts as they drift away from the source. Thus, the dispersed electrons represent a later stage in the evolution of dispersionless electrons. This evolutionary process closely mirrors that observed within Earth's dipole field, affirming that the crustal fields function similarly to a mini-magnetosphere. [ABSTRACT FROM AUTHOR]

Although solar wind‐driven convection is expected to dominate magnetospheric circulation at Mercury, its exact pattern remains poorly characterized by observations. Here we present BepiColombo Mio observations during the third Mercury flyby indicative of convection‐driven transport of low‐energy dense ions into the deep magnetosphere. During the flyby, Mio observed an energy‐dispersed ion population from the duskside magnetopause to the deep region of the midnight magnetosphere. A comparison of the observations with backward test particle simulations suggests that the observed energy dispersion structure can be explained in terms of energy‐selective transport by convection from the duskside tail magnetopause. We also discuss the properties and origins of more energetic ions observed in the more dipole‐like field regions of the magnetosphere in comparison to previously reported populations of the plasma sheet horn and ring current ions. Additionally, forward test particle simulations predict that most of the observed ions on the nightside will precipitate onto relatively low‐latitude regions of the nightside surface of Mercury for a typical convection case. The presented observations and simulation results reveal the critical role of magnetospheric convection in determining the structure of Mercury's magnetospheric plasma. The upstream driver dependence of magnetospheric convection and its effects on other magnetospheric processes and plasma‐surface interactions should be further investigated by in‐orbit BepiColombo observations. Key Points: BepiColombo Mio observed low‐energy dense ions deep within Mercury's magnetosphere during the third Mercury flybyBackward test particle simulations suggest that low‐energy ions are transported by convection from the duskside tail magnetopauseForward test particle simulations imply convection‐driven ion precipitation onto the nightside low‐latitude surface of Mercury [ABSTRACT FROM AUTHOR]