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Using data from the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission, we explore the plasma properties of Martian magnetotail current sheets (CS), to further understand the solar wind interaction with Mars and ion escape. There are some CS exhibit energetic oxygen ions that show narrow beam structures in the energy spectrum, which primarily occurs in the hemisphere where the solar wind electric field (Esw) is directed away from the planet. On average, these CS have a higher escaping flux than that of the CS without energetic oxygen ion beams, suggesting different roles in ion escape. The CS with energetic oxygen ion beams exhibits different proton and electron properties to the CS without energetic oxygen ion beams, indicating their different origins. Our analysis suggests that the CS with energetic oxygen ion beams may result from the interaction between the penetrated solar wind and localized oxygen ion plumes. Plain Language Summary: Ion escape into space, driven by solar wind interactions with Mars, plays a pivotal role in the evolution of the Martian atmosphere. An important escape channel of planetary oxygen ions is the current sheet in the nightside magnetotail. Yet, our existing understanding of plasma characteristics within this magnetic structure remains quite limited. Based on the MAVEN observations, we find the current sheets can be categorized into two distinct types according to the energy distribution patterns of oxygen ions: one is with the appearance of energetic oxygen ions with narrow beam structure, the other one is not. On average, the current sheets with energetic oxygen ion beams have a higher escaping flux than those without, suggesting different roles in ion escape. Furthermore, the two types of current sheets exhibit markedly distinct plasma properties, indicating that they have different origins. Here we suggest that the current sheet with energetic oxygen ion beams arise from the interaction between the penetrated solar wind and localized oxygen ion plumes. Key Points: Martian magnetotail current sheets occasionally exhibit energetic oxygen ions that show beam structures in the energy spectrumThe current sheets with energetic oxygen ion beam usually have a higher escaping flux than those withoutPlasma properties in current sheets differ significantly differences between those with and without energetic oxygen ion beams [ABSTRACT FROM AUTHOR]

Developmental dyslexia (DD) is a prevalent neurodevelopmental disease that poses challenges in both early intervention and long-term development for children with DD. However, there is a lack of a standardized and comprehensive tool for the diagnosis of DD in Mainland China. To develop a standardized tool (i.e., Developmental Dyslexia Scale for Standard Mandarin [DDSSM]) for the diagnosis of DD in Mainland China and evaluate its reliability and validity. DDSSM consists of 10 subtests. The initial draft was created after Delphi expert consultation, and the final version was revised to improve discriminability with a pilot study involving 450 children from grades 1–3. The reliability and validity were then confirmed with 53 children from grades 1–2. The Delphi expert consultation demonstrated that the expert panel had good authority, and that all agreed on the subtest setup. The DDSSM exhibited great internal consistency. Confirmatory factor analysis revealed that the model aligns with the theoretical structure (P > 0.05, χ2/df < 2.00, root-mean-square error of approximation (RMSEA) < 0.08, comparative fit index (CFI) > 0.90, TLI > 0.90). The Dyslexia Checklist for Chinese Children and children's academic performance agreed well with the DDSSM. The DDSAM is reliable and valid for assessing and diagnosing DD in Standard Mandarin-speaking primary school children from grades 1–2. Although a number of scales and tools have been proposed for assessing developmental dyslexia (DD) in Chinese, there is still a lack of diagnostic tools for Mandarin Chinese in Mainland China. In this study, we developed one of the most comprehensive diagnostic tools for DD in Mandarin Chinese for lower graders. We included visual-spatial attention (VA) and compounding awareness (CA), two tests that have been recently suggested as reliable measures for identifying DD in the Chinese language. This assessment tool has been verified for robust reliability and validity. This study also provided confirmation of the core deficits of DD in Chinese, which were orthographic awareness (OA). In addition, VA, rapid automatized naming (RAN) and morphological awareness (MA) were found to be the most important cognitive abilities for word reading in Chinese lower graders in this study. • A complete dyslexia development assessment tool in Mandarin Chinese was developed. • The tool incorporated indicators such as visual-spatial attention and compounding awareness found in recent studies. • Robust reliability and validity have been verified for this tool. [ABSTRACT FROM AUTHOR]

We report the first global, time‐dependent simulation of the Mars upper atmospheric responses to a realistic solar flare event, an X8.2 eruption on 10 September 2017. The Mars Global Ionosphere‐Thermosphere Model runs with realistically specified flare irradiance, giving results in reasonably good agreement with the Mars Atmosphere and Volatile EvolutioN spacecraft measurements. It is found that the ionized and neutral regimes of the upper atmosphere are significantly disturbed by the flare but react differently. The ionospheric electron density enhancement is concentrated below ∼110‐km altitude due to enhanced solar X‐rays, closely following the time evolution of the flare. The neutral atmospheric perturbation increases with altitude and is important above ∼150‐km altitude, in association with atmospheric upwelling driven by solar extreme ultraviolet heating. It takes ∼2.5 hr past the flare peak to reach the maximum disturbance and then additional ∼10 hr to generally settle down to preflare levels. Key Points: Ionospheric perturbation follows the flare in time and is concentrated mostly below 110‐km altitudeNeutral atmospheric perturbation increases with altitude and is important above 150‐km altitudeIt takes the neutral atmosphere 2.5 hr to reach the perturbation peak and 10 more hours to generally recover [ABSTRACT FROM AUTHOR]

• A locally implicit algorithm is presented to efficiently update the source terms of a coupled multifluid-Maxwell system. • A direct computing algorithm is constructed to further improve performance substantially. • The model is successfully applied to complex, large systems. • An exact algorithm based on the analytic solution is also formulated. Recently, a family of models that couple multifluid systems to the full Maxwell equations have been used in laboratory, space, and astrophysical plasma modeling. These models are more complete descriptions of the plasma than reduced models like magnetohydrodynamic (MHD) since they are derived more closely from the full kinetic Vlasov-Maxwell system, without assumptions like quasi-neutrality, negligible electron mass, etc. Thus these models naturally retain non-ideal MHD effects like electron inertia, Hall term, pressure anisotropy/nongyrotropy, displacement current, among others. One obstacle to broader application of these models is that an explicit treatment of their source terms leads to the need to resolve rapid processes like plasma oscillation and electron cyclotron motion, even when these are not important. In this paper, we suggest two ways to address this issue. First, we derive the analytic solutions to the source update equations, which can be implemented as a practical, but less generic solver. We then develop a time-centered, locally implicit algorithm to update the source terms, allowing stepping over the fast kinetic time-scales. For a plasma with S species, the locally implicit algorithm involves inverting a local (3 S + 3) × (3 S + 3) matrix only, thus is very efficient. The performance can be further increased by using the direct update formulas to skip null calculations. We present benchmarks illustrating the exact energy-conservation of the locally implicit solver, as well as its efficiency and robustness for both small-scale, idealized problems and large-scale, complex systems. The locally implicit algorithm can be also easily extended to include other local sources, like collisions and ionization, which are difficult to solve analytically. [ABSTRACT FROM AUTHOR]

Background: Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder in school-aged children. The lack of objective biomarkers for ADHD often results in missed diagnoses or misdiagnoses, which lead to inappropriate or delayed interventions. Eye-tracking technology provides an objective method to assess children's neuropsychological behavior., Objective: The aim of this study was to develop an objective and reliable auxiliary diagnostic system for ADHD using eye-tracking technology. This system would be valuable for screening for ADHD in schools and communities and may help identify objective biomarkers for the clinical diagnosis of ADHD., Methods: We conducted a case-control study of children with ADHD and typically developing (TD) children. We designed an eye-tracking assessment paradigm based on the core cognitive deficits of ADHD and extracted various digital biomarkers that represented participant behaviors. These biomarkers and developmental patterns were compared between the ADHD and TD groups. Machine learning (ML) was implemented to validate the ability of the extracted eye-tracking biomarkers to predict ADHD. The performance of the ML models was evaluated using 5-fold cross-validation., Results: We recruited 216 participants, of whom 94 (43.5%) were children with ADHD and 122 (56.5%) were TD children. The ADHD group showed significantly poorer performance (for accuracy and completion time) than the TD group in the prosaccade, antisaccade, and delayed saccade tasks. In addition, there were substantial group differences in digital biomarkers, such as pupil diameter fluctuation, regularity of gaze trajectory, and fixations on unrelated areas. Although the accuracy and task completion speed of the ADHD group increased over time, their eye-movement patterns remained irregular. The TD group with children aged 5 to 6 years outperformed the ADHD group with children aged 9 to 10 years, and this difference remained relatively stable over time, which indicated that the ADHD group followed a unique developmental pattern. The ML model was effective in discriminating the groups, achieving an area under the curve of 0.965 and an accuracy of 0.908., Conclusions: The eye-tracking biomarkers proposed in this study effectively identified differences in various aspects of eye-movement patterns between the ADHD and TD groups. In addition, the ML model constructed using these digital biomarkers achieved high accuracy and reliability in identifying ADHD. Our system can facilitate early screening for ADHD in schools and communities and provide clinicians with objective biomarkers as a reference., (©Zhongling Liu, Jinkai Li, Yuanyuan Zhang, Dan Wu, Yanyan Huo, Jianxin Yang, Musen Zhang, Chuanfei Dong, Luhui Jiang, Ruohan Sun, Ruoyin Zhou, Fei Li, Xiaodan Yu, Daqian Zhu, Yao Guo, Jinjin Chen. Originally published in JMIR mHealth and uHealth (https://mhealth.jmir.org), 29.11.2024.)

When the solar wind interacts with the ionosphere of an unmagnetized planet, it induces currents that form an induced magnetosphere. These currents and their associated magnetic fields play a pivotal role in controlling the movement of charged particles, which is essential for understanding the escape of planetary ions. Unlike the well-documented magnetospheric current systems, the ionospheric current systems driven by solar wind and atmospheric neutral winds have not been quantitatively observed, which constrains the quantification of energy transfer from stars to these planets. Here, utilizing eight years of data from the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission, we investigate the global distribution of ionospheric currents on Mars. We identify two distinct current systems in the ionosphere: one aligns with the solar wind electric field but exhibits hemispheric asymmetry perpendicular to the solar wind electric field direction; the other corresponds to the flow pattern of annually averaged neutral winds. We propose that these two current systems are driven by the solar wind and atmospheric neutral winds, respectively. Our findings reveal that Martian ionospheric dynamics are influenced by the neutral winds from below and the solar wind from above, highlighting the complex and intriguing nature of current systems on unmagnetized planets., (© 2024. The Author(s).)

Mars lacks a global magnetic field, and instead possesses small-scale crustal magnetic fields, making its magnetic environment fundamentally different from intrinsic magnetospheres like those of Earth or Saturn. Here we report the discovery of magnetospheric ion drift patterns, typical of intrinsic magnetospheres, at Mars using measurements from Mars Atmosphere and Volatile EvolutioN mission. Specifically, we observe wedge-like dispersion structures of hydrogen ions exhibiting butterfly-shaped distributions (pitch angle peaks at 22.5°-45° and 135°-157.5°) within the Martian crustal fields, a feature previously observed only in planetary-scale intrinsic magnetospheres. These dispersed structures are the results of drift motions that fundamentally resemble those observed in intrinsic magnetospheres. Our findings indicate that the Martian magnetosphere embodies an intermediate case where both the unmagnetized and magnetized ion behaviors could be observed because of the wide range of strengths and spatial scales of the crustal magnetic fields around Mars., (© 2023. The Author(s).)

The presence of an atmosphere over sufficiently long timescales is widely perceived as one of the most prominent criteria associated with planetary surface habitability. We address the crucial question of whether the seven Earth-sized planets transiting the recently discovered ultracool dwarf star TRAPPIST-1 are capable of retaining their atmospheres. To this effect, we carry out numerical simulations to characterize the stellar wind of TRAPPIST-1 and the atmospheric ion escape rates for all of the seven planets. We also estimate the escape rates analytically and demonstrate that they are in good agreement with the numerical results. We conclude that the outer planets of the TRAPPIST-1 system are capable of retaining their atmospheres over billion-year timescales. The consequences arising from our results are also explored in the context of abiogenesis, biodiversity, and searches for future exoplanets. In light of the many unknowns and assumptions involved, we recommend that these conclusions must be interpreted with due caution., Competing Interests: The authors declare no conflict of interest.