Model Simulation of Convectively Lofted Ice Contribution to Stratospheric Water Vapor

Changes in the amount of stratospheric water vapor can affect both the chemistry and climate in the stratosphere and troposphere. Convectively lofted ice near and above the tropopause can evaporate and contribute to stratospheric water vapor. Here we conduct several experiments using a trajectory model driven by two chemistry-climate models (CCMs) to study the contribution of lofted ice to stratospheric water vapor. We show that the largest amount of evaporation of convectively lofted ice occurs in the Tropical Tropopause Layer (TTL) and above the Lagrangian cold point, and we find two key regions for lofted ice evaporation: the Asian monsoon region during JJA (June, July, and August) and the tropical western Pacific during DJF (December, January, and February), regions where convection frequently occurs and the evaporation rate of lofted ice is high. The distribution of net contribution is mainly determined by the degree of subsaturation in the TTL, and the net contribution of lofted ice is then transported to the rest of the stratosphere by the general circulation. Over the 21st century, an increase of subsaturation leads both the lofted ice evaporation rate and the net contribution to increase. It explains part of the increase of stratospheric water vapor over the 21st century

Toward Understanding Key Estimation in Learning Robust Humanoid Locomotion

Accurate state estimation plays a critical role in ensuring the robust control of humanoid robots, particularly in the context of learning-based control policies for legged robots. However, there is a notable gap in analytical research concerning estimations. Therefore, we endeavor to further understand how various types of estimations influence the decision-making processes of policies. In this paper, we provide quantitative insight into the effectiveness of learned state estimations, employing saliency analysis to identify key estimation variables and optimize their combination for humanoid locomotion tasks. Evaluations assessing tracking precision and robustness are conducted on comparative groups of policies with varying estimation combinations in both simulated and real-world environments. Results validated that the proposed policy is capable of crossing the sim-to-real gap and demonstrating superior performance relative to alternative policy configurations

Enhanced Immune Responses Conferring Cross-Protection by Skin Vaccination With a Tri-Component Influenza Vaccine Using a Microneedle Patch

Skin vaccination using biodegradable microneedle patch (MNP) technology in vaccine delivery is a promising strategy showing significant advantages over conventional flu shots. In this study, we developed an MNP encapsulating a 4M2e-tFliC fusion protein and two types of whole inactivated influenza virus vaccines (H1N1 and H3N2) as a universal vaccine candidate. We demonstrated that mice receiving this tri-component influenza vaccine via MNP acquired improved IgG1 antibody responses with more balanced IgG1/IgG2a antibody responses and enhanced cellular immune responses, including increased populations of IL-4 and IFN-γ producing cells and higher frequencies of antigen-specific plasma cells compared with intramuscular injection. In addition, stronger germinal center reactions, increased numbers of Langerin-positive migratory dendritic cells, and increased cytokine secretion were observed in the skin-draining lymph nodes after immunization with the tri-component influenza MNP vaccine. The MNP-immunized group also possessed enhanced protection against a heterologous reassortant A/Shanghai/2013 H7N9 (rSH) influenza virus infection. Furthermore, the sera collected from 4M2e-tFliC MNP-immunized mice were demonstrated to have antiviral efficacy against reassortant A/Vietnam/1203/2004 H5N1 (rVet) and A/Shanghai/2013 H7N9 (rSH) virus challenges. The immunological advantages of skin vaccination with this tri-component MNP vaccine could offer a promising approach to develop an easily applicable and broadly protective universal influenza vaccine

Over 18% ternary polymer solar cells enabled by a terpolymer as the third component

“Ternary blending” and “random terpolymerization” strategies have both proven effective for enhancing the performance of organic solar cells (OSCs). However, reports on the combination of the two strategies remain rare. Here, a terpolymer PM6-Si30 was constructed by inserting chlorine and alkylsilyl-substituted benzodithiophene (BDT) unit (0.3 equivalent) into the state-of-the-art polymer PM6. The terpolymer exhibitsadeep highest-occupied-molecular-orbital energy and good miscibility with both PM6 and BTP-eC9 (C9) and enables its use as a third component into PM6:PM6-Si30:C9 bulk-heterojunction for OSCs. The resulting cells exhibit maximum power conversion efficiency (PCE) of 18.27%, which is higher than that obtained for the optimized control binary PM6:C9-based OSC (17.38%). The enhanced performance of the PM6:PM6-Si30:C9 cells is attributed to improved charge transport, favorable molecular arrangement, reduced energy loss and suppressed bimolecular recombination. The work demonstrates the potential of random terpolymer as a third component in OSCs and highlights a new strategy for the construction of a ternary system with improved photovoltaic performance

Hunga Tonga-Hunga Ha’apai Volcano Impact Model Observation Comparison (HTHH-MOC) Project: Experiment Protocol and Model Descriptions

The 2022 Hunga volcanic eruption injected a significant amount of water vapor and a moderate amount of sulfur dioxide into the stratosphere causing observable responses in the climate system. We have developed a model-observation comparison project to investigate the evolution of volcanic water and aerosols, and their impacts on atmospheric dynamics, chemistry, and climate, using several state-of-the-art chemistry climate models. The project goals are: 1. Evaluate the current chemistry-climate models to quantify their performance in comparison to observations; and 2. Understand atmospheric responses in the Earth system after this exceptional event and investigate the potential impacts in the projected future. To achieve these goals, we designed specific experiments for direct comparisons to observations, for example from balloons and the Microwave Limb Sounder satellite instrument. Experiment 1 is a free-running ensemble experiment from 2022 to 2031. Experiment 2 is a nudged-run experiment from 2022 to 2023 using observed meteorology. To allow participation of more climate models with varying complexities of aerosol simulation, we include two sets of simulations in Experiment 2: Experiment 2a is designed for models with internally-generated aerosol while Experiment 2b is designed for models using prescribed aerosol surface area density. We take model results from the previously developed Tonga-MIP to fulfill Experiment 3, which focuses on the initial dispersion and microphysical evolution of aerosol and water plumes. Experiment 4 is designed to understand the climate impact on the mesosphere from 2022–2027, for which the experiment design is the same as Experiment 1 but for models that resolve the upper stratosphere and mesosphere

Mechanisms of noncovalent β subunit regulation of NaV channel gating

Voltage-gated Na(+) (NaV) channels comprise a macromolecular complex whose components tailor channel function. Key components are the non-covalently bound β1 and β3 subunits that regulate channel gating, expression, and pharmacology. Here, we probe the molecular basis of this regulation by applying voltage clamp fluorometry to measure how the β subunits affect the conformational dynamics of the cardiac NaV channel (NaV1.5) voltage-sensing domains (VSDs). The pore-forming NaV1.5 α subunit contains four domains (DI-DIV), each with a VSD. Our results show that β1 regulates NaV1.5 by modulating the DIV-VSD, whereas β3 alters channel kinetics mainly through DIII-VSD interaction. Introduction of a quenching tryptophan into the extracellular region of the β3 transmembrane segment inverted the DIII-VSD fluorescence. Additionally, a fluorophore tethered to β3 at the same position produced voltage-dependent fluorescence dynamics strongly resembling those of the DIII-VSD. Together, these results provide compelling evidence that β3 binds proximally to the DIII-VSD. Molecular-level differences in β1 and β3 interaction with the α subunit lead to distinct activation and inactivation recovery kinetics, significantly affecting NaV channel regulation of cell excitability

Practical sketching algorithms for low-rank tucker approximation of large tensors

Low-rank approximation of tensors has been widely used in high-dimensional data analysis. It usually involves singular value decomposition (SVD) of large-scale matrices with high computational complexity. Sketching is an effective data compression and dimensionality reduction technique applied to the low-rank approximation of large matrices. This paper presents two practical randomized algorithms for low-rank Tucker approximation of large tensors based on sketching and power scheme, with a rigorous error-bound analysis. Numerical experiments on synthetic and real-world tensor data demonstrate the competitive performance of the proposed algorithms